8> ; CORNELL UNIVERSITY LIBRARY DATE DUE J[fN \ p. m* mUM .CORNELL UNIVERSITY LIBRARY _3_1924 092 298 235 Cornell University Library The original of this book is in the Cornell University Library. There are no known copyright restrictions in the United States on the use of the text. http://www.archive.org/details/cu31924092298235 THE WORKS OP THOMAS REII), Di). NOW FULLY COLLECTED, WITH SELECTIONS FROM HIS UNPUBLISHED LETTERS. PREFACE, NOTES AND SUPPLEMENTARY DISSERTATIONS, BY SIR WILLIAM HAMILTON, BART., ADVOCATE ; A.M. (OXON.) ; ETC. ; CORRESPONDING MEMBER OF THE INSTITUTE OF FRANCE ; HONORARY MEMBER OF THE AMERICAN ACADEMY OF ARTS AND SCIENCES J OF THE LATIN SOCIETY OF JENA ; ETC. ; PROFESSOR OF LOGIC AND METAPHYSICS IN THE UNIVERSITY OF EDINBURGH. PREFIXED, STEWART'S ACCOUNT OF THE LIFE AND WRITINGS OF REID. VOL. I. EIGHTH EDITION. EDINBURGH MACLACHLAN AND STEWART. LONDON: LONGMAN, GREEN, LONGMAN, ROBERTS, AND GREEN. MDCCCLXXX. <$. 2-2-1 ON EARTH, THERE IS NOTHING GREAT BUT MAN; IN MAN, THERE IS NOTHING GREAT BUT MIND. TO VICTOR COUSIN, PEER OF FRANCE, LATE MINISTER OF PUBLIC INSTRUCTION, MEMBER OF THE INSTITUTE, PROFESSOR OF PHILOSOPHY, ETC., ETC., THIS EDITION OF THE WORKS OF REID IS DEDICATED; NOT ONLY, IN TOKEN OF THE EDITOR'S ADMIRATION OF THE FIRST PHILOSOPHER OF FRANCE, BUT, AS A TRIBUTE, DUE APPROPRIATELY AND PRE-EMINENTLY TO THE STATESMAN, THROUGH WHOM SCOTLAND HAS BEEN AGAIN UNITED INTELLECTUALLY TO HER OLD POLITICAL ALLY, AND THE AUTHOR'S WRITINGS, (THE BEST RESULT OF SCOTTISH SPECULATION,) MADE THE BASIS OF ACADEMICAL INSTRUCTION IN PHILOSOPHY THROUGHOUT THE CENTRAL NATION OF EUROPE. CONTENTS. Paoe Dedication, ...... Table of Contents, ..... iii EDITOR'S PREFACE, .... xv DUGALD STEWART'S ACCOUNT OF THE LIFE AND WRITINGS OF THOMAS REID, D.D. Section I. From Dr Reid's birth till the date of his latest publication, 3 II. Observations on the Spirit and scope of Dr Reid's philosophy, 11 III. Conclusion of the Narrative, ... 29 Notes, .... 35 RE ID'S (I.— WRITINGS NOT INTENDED FOR PUBLICATION.) LETTERS. A. To Drs Andrew and David Skene, 1764 — 1770, . . 39 B To Lord Karnes, 1772—1782, . . .60 C— To Dr James Gregory, 1783—1793, ... 62 D. To the Rev. Archibald Alison, 1790, ... 89 E.— To Prof. Robison, 1792, ..... 89 F To David Hume, 1763, . • . . 91 (II.— WRITINGS INTENDED AND PREPARED FOR PUBLICATION.) A— INQUIRY INTO THE HUMAN MIND. Dedication, . ■ 95 CHAPTER I.— Inikoduction. Section I. The Importance of the subject, and the Means of prosecuting it, 97 II. The Impediments to our knowledge of the mind, . 98 III. The Present State of this part of philosophy. Of Des Cartes, Male- branche, and Locke, .... 99 IV. Apology for tliose philosophers, . • 101 £ V. Of Bishop Berkeley ; the " Treatise of Human Nature " [by Humej] and of Scepticism, .... 101 VI. Of the " Treatise of Human Nature" . . 102 VII. The system of all these authors is the same, and leads to Scepticism, 103 VIII. We ought not to despair of a better, . ■ . 103 CHAPTER II.— Or Smelling. Section I. The Order of proceeding. Of the medium and organ of Smell, 104 II. The Sensation considered abstractly, . _. 105 III. Sensation and Remembrance, natural principles of Belief , 105 IV. Judgment and Belief in some cases precede Simple Apprehension, 106 V. Two Theories of the nature of Belief refuted. Conclusions from what hath been said, . . • 107 vi CONTENTS. Paob ESSAY III._Of Memort. Cuapxer I. Things obvious and certain with regard to Memory, . 339 IF. Memory an original faculty, . ■ ■ 340 III. Of Duration, ..... 342 IV. Of Identity, . . . . 344 V. Mr Locke's account of the Origin of our Ideas, and particularly of the idea of Duration, . . • 346 VI. Mr Locke's account of our Personal Identity, . 350 VII. Theories concerning Memory, . . • 353 ESSAY IV Of Conception. Chapter I. Of Conception, or Simple Apprehension in general, . 360 II. Tlieories concerning Conception, . . 368 III. Mistakes concerning Conception, . . . 375 IV. Of the Train of Thought in the mind, . . 379 ESSAY V.— Of Abstraction. Chapter I. Of General Words, .... 389 II. Of General Conceptions, . . . 391 III. Of general conceptions formed by Analysing objects, . 394 IV. Of general conceptions formed by Combination, . 39S V. Observations concerning the Names given to our general notions, 403 VI. Opinion of philosophers about Universals, . . 405 ESSAY VI Of Judgment. Chapter I. Of Judgment in general, . . .413 II. Of Common Sense, .... 421 III. Sentiments of philosophers concerning Judgment, . 426 IV. Of First Principles in general, • . . 434 V. The first principles of Contingent Truths. [On Consciousness,] 441 VI. First principles of Necessary Truths, . . 452 VII. Opinions, ancient and modern, about First Principles, . 462 VIII. Of Prejudices, the causes of error, . . 468 ESSAY VII.— Of Reasoning. Chapter I. Of Reasoning in general, and of Demonstration, . 475 II. Whether Morality be capable of demonstration, . 478 III. Of Probable Reasoning, .... 481 IV. Of Mr Hume's Scepticism with regard to Reason, , 484 ESSAY VIII.— Of Taste. Chapter I. Of Taste in general, . II. Of the Objects of taste, and first of Novelty, . 493 III. Of Grandeur, .... 404 IV, Of Beauty, . • • . 498 490 CONTENTS. Vll C— ESSAYS ON THE ACTIVE POWERS OF THE HUMAN MIND. Introduction, ...... 51] ESSAY I. — Of Active Power in General. Chapter I. Of the Notion of Active Power, . . . 512 II. The same subject, .... 515 III. Of Mr Locke's account of our Idea of Power, . 518 IV. Of Mr Hume's opinion of the Idea of Power, . . 520 V. Whether beings that have no Will nor Understanding may have Active Power ? . . . . 522 V I. Of the Efficient Causes of the phenomena of nature, . 525 VII. Of the Extent of Human Power, . 527 ESSAY II.— Of the Will. Chapter I. Observations concerning the Will, . . . 530 II. Of the influence of Incitements and Motives upon the Will, 533 III. Of operations of mind which may be called Voluntary, 537 IV. Corollaries, . . . 541 ESSAY III. — Of the Principles of Action, PART I.- — Op tue Mechanical Principles of Action. Chapter I. Of the Principles of Action in general, II. Of Instinct, III. Of Habit, 543 545 550 PART II Of the Animal Principles of Action Chapter I. Of Appetites, . . . . 551 II. Of Desires, . . . 554 III. Of Benevolent Affection in general . . 558 IV. Of the particular Benevolent Affections, . . 560 V. Of Malevolent Affections, . . . 566 VI. Of Passion, ..... 570 VII. Of Disposition, . . . 575 VIII. Of Opinion, ..... 577 PART III Of the Rational Principles of Action. Chapter I. There are Rational Principles of action in man, . 579 II. Of regard to our Good upon the Whole, . 580 III. The Tendency of this Principle, . . 582 IV. Defects of this Principle, .... 584 V. Of the notion of Duty, Rectitude, Moral Obligation, . 588 VI. Of the Sense of Duty, . ... 589 VII. Of Moral Approbation and Disapprobation, . 592 VIII. Observations concerning Conscience, . . • 594 ESSAY IV Of the Liberty of Moral Agents. Chapter I. The notions of Moral Liberty and Necessity stated, . 599 II. Of the words, Cause and Effect, Adion, and Aclive Power, 603 vnf ClIAJ !R III. Causes of the Ambiguity of those word: IV. Of the influence of Motives, V. Liberty consistent with Government, VI. First Argument for Liberty, VII. Second Argument, VIII. Third Argument, IX. Of Arguments for Necessity, X. The same subject, XI. Of the Permission of Evil, 605 608 613 61S 020 022 024 620 632 ESSAY V— Of Morals. Chapter I. Of the First Principles of Morals, . ■ . 637 II. Of Systems of Morals, "... 640 III. Of Systims of Natural Jurisprudence, . . 643 IV. Whether an action deserving Moral Approbation, must be done with the Belief of its being Morally Good, . 646 V. Wlielher Justice be a Natural, or an Artificial Virtue, . 651 VI. Of the nature and obligation of a Contract, 662 VII. That Moral Approbation implies a real Judgment, . 670 D ACCOUNT OF ARISTOTLE'S LOGIC. CHAPTER I.— Of the First Three Treatises. Section I. Of the Author, .... II. Of the Porphyry's Introduction, III. Of the Categories, IV. Of the book Concerning Interpretation, 681 083 683 685 CHAPTER II.— Remarks. Section I. On the Five Predicables, II. On tlie Ten Categories, and on Divisions in genera/, III. On Distinctions, IV. On Definitions, V. On tlie structure of Speech, VI- On Propositions, 685 6S7 689 ^90 691 092 CHAPTER III. — Account of the First Analytics. Section I. Of the Conversion of Propositions, . , (593 II. Of the Figures < nd Modes of Pure Syllogisms, . 694 III. Of tlie Invention [Discovery} of a Middle- Term, . 695 IV. Of the remaining part of the First Book, . 695 V. Of the Second Book of tlie First Analytics, , 695 CHAPTER IV Remarks. Section I. Of the Conversion of Propositions, «9(i CONTENTS. IX Section IT. On Additions made to Aristotle's Theory, . 697 III. On Examples used to illustrate this Theory, . . 698 IV. On the Demonstration of the Theory, . . G99 V. On this Theory considered as an Engine of Science, . 701 VI. On Modal Syllogisms, . , . 702 VII. On Syllogisms that do not belong to Figure and Mode, . 704 CHAPTER V. — Account of the Remaining Books of the Okganon. Section I. Of the Last Analytics, .... 705 II. Of the Topics, ' . . . 70f> III. Of 'he booh concerning Sophisms, . . . 707 CHAPTER VI. — Reflections on tub Utii.itt op Logic, and tub Means of its Improvement. Section T. Of the Utility of Logic, . 703 II. Of the Improvement of Logic, 711 E — ESSAY ON QUANTITY. [Occasion and grounds of the Discussion,] 715 Of the Newtonian Measure of Force, . 717 Of the Leibnilzian Measure of Force, . . 718 Reflections on this Controversy, . . 719 F.— ACCOUNT OF THE UNIVERSITY OF GLASGOW. Introduction, ...... 721 I. History of the University before the Reformation, . 721 II. Ancient Constitution, . . . 722 III. History after the Reformation, . . 727 IV. Modern Constitution, . . . 729 V. Donations, . . . 730 VI. Present State, . . 732 VII. Conclusion, . . 738 3 EDITOR'S SUPPLEMENTARY DISSERTATIONS. 5;A.)— ON THE PHILOSOPHY OF COMMON SENSE; OR, OUR PRIMARY ''BELIEFS CONSIDERED AS THE ULTIMATE CRITERION OF TRUTH. Section I. The Meaning of the Doctrine, and Purport of the Argument, of Common Sense, .... 742 II. The Conditions of the Legitimacy, and legitimate application, of the argument, . . . 749 III. That it is one strictly Philosophical and scientific, . 751 * IV. The Essential diameters by which our primary beliefs, or the principles of Common Sense, are discriminated, . 754 V- The Nomenclature, that is, the various appellations by which these have been designated, . . 7f>."> CONTENTS, Section VJ. The Universality of tlus philosophy of Common Sense ; or its general recognition, in reality and in name, shown by a chronological series of Testimonies from llie dawn of speculation to the pre- sent day, ■ ■ i '" (B.)— OF PRESENTATIVE AND REPRESENTATIVE KNOWLEDGE. Section I. The distinction of Presentative, Intuitive or Immediate, and of Representative or Mediate cognition ; with the various signifi- cations of the term Object, its conjugates and correlatives, 804 Section II. Errors of Reid and other Philosophers, in reference to the preced- ing distinctions, .... 812 (C.)— ON THE VARIOUS THEORIES OF EXTERNAL PERCEPTION. Section I. Systematic Schemes, from different points of view, of the various theories of the relation of External Perception to its Object ; and of the various systems of Philosophy founded thereon, 816 II. What is the character, in this respect, of Reid's doctrine of Percep- tion? . . . . .819 (D.)— DISTINCTION OF THE PRIMARY AND SECONDARY QUALITIES OF BODY. Section I. Historically considered, . . . 825 II. Critically considered. Three classes (Primary, Secundo-Primary, and Secondary Qualities,) established, . 845 (D *.)— PERCEPTION PROPER AND SENSATION PROPER. Section I. Principal momenta of the Editor's doctrine of Perception, (A) in itself, and (B) in contrast to that of Reid, Stewart, Royer Collard, and other philosophers of the Scottish School, 876 II. Historical notices in regard to the distinction of Perception proper and Sensation proper, ■ . . 886 (D **.) CONTRIBUTION TOWARDS A HISTORY OF THE DOCTRINE OF MENTAL SUGGESTION OR ASSOCIATION, 889 (D ***.)— OUTLINE OF A THEORY OF MENTAL REPRODUCTION, SUGGESTION OR ASSOCIATION. Section I. Laws of Mental Succession, as General. — (A.) Not of Reproduc- tion proper, uniform — (B.) Of Reproduction proper, not uniform : as possible ; as actual ; as direct, — Abstract or Primary law of Repetition ; as indirect, — Abstract or Primary law of Redintegration, Concrete or Secondary law of Pre- ference, ..... 910 II. Laws of Mental Succession, as SjieciaL — Of Reproduction : (A.) Abstract or Primary,— modes of the laws of Repetition and Redintegration, one or both ; — (B.) Concrete or Secondary,— modes of the law of Preference. CONTENTS. XI (E.)-ON THE CORRELATIVE APPREHENSIONS OF COLOUR, AND OF EXTENSION AND FIGURE. Section I. On the Cm-relation of Colour with Extension and Figure in visual Perception and Imagination, . . . 917 II. On the Philosophy of the Point, the Line, and the Surface : in illus- tration of the reality, nature, and visual perception of breadth- less lines, . . . 921 (F.)— ON LOCKE'S NOTION OF THE CREATION OF MATTER, 924 (G.)— ON THE HISTORY OF THE WORD IDEA, . 925 (H.)-ON CONSCIOUSNESS. Section I. ReicVs reduction of Consciousness to a special faculty shewn to be inaccurate. Consciousness the fundamental condition of all our mental energies and affections, . . . 929 II. Conditions and Limitations of Consciousness. General Laws of Variety and Succession. Special characteristics of Conscious- ness. Philosophy of the Conditioned in relation to the notions of Substance and Cause, . . .932 [III.] Historical references — i. On the conditions of Consciousness ; ii. On acts of mind beyond the sphere of Consciousness, . 938 (I.) -ON THE HISTORY OF THE TERMS CONSCIOUSNESS, ATTENTION, AND REFLECTION. Section I. Extracts explanatory of Sir W. Hamilton's view of the distinction between Consciousness, Attention, and Reflection, with special reference to the opinions of Reid and Stewart, . . 940 II. Historical notices of the use of the terms Consciousness, Attention, and Reflection, . . 942 (K.)— THAT THE TERMS IMAGE, IMPRESSION, TYPE, &c, IN PHILO- SOPHICAL THEORIES OF PERCEPTION, ARE NOT TO BE TAKEN LITERALLY, . ... 948 (L.)— ON THE PLATONIC DOCTRINE OF PERCEPTION, . 950 1M.)— ON THE DOCTRINE OF SPECIES, AS HELD BY ARISTOTLE AND THE ARISTOTELIANS. [Section I.] Origin of -the theory as a metaphysical and physical hypothesis — i opinion of Aristotle — of the Schoolmen — theory of intentional species, impressed and expressed, sensible and, intelligible — various opinions on the whole hypothesis, . . 951 Xli CONTENTS. Paob [Section II.] Translations of passages exhibiting the nominalist doctrine of species, . ■ ■ "57 (N.V--THE CARTESIAN THEORY OF PERCEPTION AND IDEAS, , 961 (0.)— LOCKE'S OPINION ABOUT IDEAS, (P.)— ON MALEBRANCHE'S THEORY, 96fi (Q.)-ON HUME'S ASSERTION ABOUT THE IDEAS OF POWER AND CAUSE, AND BROWN'S CRITICISM OF REID, . 968 (R.)— ON THE CARTESIAN DOUBT, . . 969 (S.)— ON REID'S BORROWING FROM GASSENDI THE OPINION OF ALEXANDER AND THE NOMINALISTS, . 970 (T\)-ON THE QUALITY OF NECESSITY AS A CRITERION OF THE ORIGINALITY OF A COGNITION, 971 (U.)-ON THE ARGUMENT FROM PRESCIENCE AGAINST LIBERTY. [Section I.] Liberty vindicated by the Philosophy of the Conditioned, . 97?, [II.] Impossibility of reconciling Liberty and Prescience — various theories mi this point, . . . 970 [III.] Extracts from A quinas and Cajetanus, . . 970 (U*.)— ON SCIENTIA MEDIA, . . .OS! (V.)— ARISTOTLE'S MERITS AS A LOGICIAN : HIS OWN AND KANT'S TESTIMONY, ..... 982 (W.)— THE SCIENCES OF OBSERVATION TO BE STUDIED BEFORE THOSE OF REFLECTION, . 9S5 ■ CONTENTS. X1U Pagb (X.)— ON THE DIFFERENCE BETWEEN CONCEPTIONS (BEGRIFFE) AND INTUITIONS (ANSCHAUUNGEN), . . 986 (Y.)— ON EGOISM 988 ADDENDA, . . . . 989* POSTSCRIPT, .... 989 INDICES, 991 MEMORANDA FOR PREFACE. [From the Advertisement prefixed to this work, it appears that Sir William Hamilton's contributions as Editor were intended to include, in addition to the Foot-Notes and Supplementary Dissertations, a General Preface to the whole. This Preface was never written, and its plan can only be conjectured from a few memo- randa marked as intended for it, and some fragments apparently designed to be incorporated with it. The principal of these have been printed below. — Ed.] [Of the Scottish Philosophy in General.] Results of Locke's philosophy — Col- lins, &c, see Cousin in Vacherot, [Cours de 1819-20, partie2,Leconl.*] Berkeley, Hume — adopted at first by Scottish school; Reid's reaction. Hume's scepticism proceeds in two momenta. 1°, In shewing that the notions of Cause and Effect, Substance and Accident, which he wishes to make merely subjec- tive, have no genuine necessity; (under and after this, but not developed, that even if the necessity be not a bastard one — from custom — it is at best only a legitimate subjective one, and without objective validity.) 2°, In shewing that the mind is not con- scious of any real existence in perception ; that its representations are no guarantee for anything represented (Idealism. ) Now Kant and Reid both combated Hume. Kant applied himself to the causal nexus ; Reid to the idealism. Shew how both were equally intent on shewing that causality is a real neces- sity of mind. Though both only subjective, Kant more articulate. How, in regard to idealism, Kant con- firmed Hume, giving his premises, whereas Reid's doctrine, though confused and vacillating, was a real refutation. [These memoranda have been partly worked out in a paper printed in the Appendix to the Lectures on Metaphysics, vol. i., p. 392 sq. Another aspect of the Scottish Philosophy, in relation to that of Germany, is indicated in the following fragment, which is apparently related to the reference above, p. 793. — Ed.] * Sec also M. Cousin's own edition of these Lectures, LeQon 2. — Ed. It was Jacobi who first in Germany at- tacked the mediate and demonstrating philosophy of the Leibuitians, and shewed the necessity of immediate knowledge. This he took from Reid. — See Prancke, p. 227 sq. Schulze, another great pro- moter of this. — Ibid., p. 230. [The purport of this memorandum is explained by the following extracts, translated from Francke's work, Das selbststaendige und reine Leben des Gefuehls, als des Geistes urspruenglichen Urtheils, u.s.w. Leipzig, 1838 : — " The union of the English and French empiricism with the German logical ra- tionalism produced that maxim of the philosophy of reflection, which maintains that nothing can be admitted as truth which cannot be proved, or logically de- duced, from the perceptions of sense ; a position which leads, as a natural conse- quence, to the scepticism of Hume. On the other hand, Reid, Beattie, and Oswald, advocating the hitherto obscured element of Feeling, maintained that the human mind possesses immediately in conscious- ness principles of knowledge independent of experience; and a more cautious at- tempt was made by Richard Price to shew that the Understanding, or Faculty of Thought, as distinguished from the deduc- tive faculty, is essentially different from the faculty of- sense, and is a source of special representations distinct from those of the senses. Yet, on the whole, all these writers, as regards the scientific vindication of their teaching, were com- pelled to place the foundation of the immediate cognition of the higher truths of reason in a Common Sense ; and the assumption of this protended source ne- cessarily involved suspicion and doubt ns regards the truth of the cognitions derived from it. And so also Jacobi, if MEMORANDA FOR PREFACE. we except the negative, polemical side of his teaching, wherein he certainly accom- plished much, has advanced little or nothing beyond his English predecessors in laying a firm scientific foundation for his own view ; though he was the first among ourselves who, in the controversy with the disciples of Wolf and other cog- nate schools, by the employment of the terms feeling and belief, directed attention to the necessity of acknowledging the importance of immediate cognition and its consciousness "Although Jacobi's system, on account of its vacillating language, and still more on account of its intuitive narrowness and subjective character, was not fitted to bene- fit philosophy immediately, it had, not- withstanding, a foundation of truth, which could not long fail of producing its effect. Many soon became clearly convinced that the Kantian philosophy also was liable to the charge of onesidedness, and failed to satisfy the requirements of the entire man : they acknowledged that Jacobi, notwith- standing the enthusiastic vehemence of his decisions, had seized and brought to light a principle of our mental life hitherto marvellously overlooked, the discovery of which would henceforth fill up a great void in the culture of the age, and the recognition of which was indispensable to the preservation and progress of philoso- phy. Even men who could not directly be classed as belonging to the school of Jacobi, the clearest and most cautious thinkers, acknowledged the importance of the distinction between mediate and im- mediate knowledge, and between the mediate and immediate consciousness of it ; and although they would not concede to Feeling an independent significance, and were unable to assign to it a sure psychological position, they at least saw clearly, and proved conclusively, that the power and efficacy of this Feeling must be a necessary condition of knowledge antecedent to all determinate conceptions and reasonings. Among these men may be especially mentioned the so - called sceptic, (who in his later writings is a natural realist,) G-. E. Schulze,* Bouter- wek,t and Gerlach.f ' ' Schulze, indeed, regards the Feelings as the most obscure and variable phase of the * Psyoh. Anthropol. ed. 2, § 161, pp. 259, 260 : Encycl. der philos. Wissensch. §§ 39, 115 ; Kritik dor theor. Philos. i. p. 702-720; Ueber dio mensohl. Erkenntniss, § 45-50, pp. 155-174. t Lehrb. der philos. Wissensch. Apod. p. 16-8(5. t Lclu-b. der philos. "Wissensch. i. § 48, p. 48. mental life : he holds them to be incapable of establishing or proclaiming anything ob- jective, and hence to be useless as princi- ples for the demonstration of truth ; but he repeatedly asserts the existence in the human consciousness of certain funda- mental assumptions, of which, by the con- stitution of our nature, we are unable arbi- trarily to divest ourselves, and which have a place in all natural science and in moral and religious convictions. It is true that Schulze did not penetrate to a complete insight into the nature of demonstrative knowledge and transcendental idealism ; and hence, from the position of his natural objective realism, he is unable to discover that our ideal convictions can attain to an equal certainty with the natural conviction of knowledge based on intuition. Bouter- wek, adhering more closely to Jacobi's doctrine, speaks of the consciousness of the original feeling of truth as the first witness of certainty in all human convic- tion ; but, like Jacobi, he seems to believe in a perceptive power of the internal sense, by which even demonstrative phi- losophical cognitions may be realised in consciousness Fries is the first who, by opening a new path of anthropologico-critical inquiry, has com- pletely and fully succeeded in organi- cally uniting the immediate products of Jacobi's philosophy with the results of the Kantian criticism, and thus in exhibiting in a clear and scientific light, from the laws of the theory of man's mental life, the relation of Knowledge to Belief, of the natural and ideal aspect of the world, as well as the important relation between the feeling and the conception of the truth. He is the first philosopher in whose system Feeling has won an independent and firmly established position among the philoso- phical convictions of the reason." * — Ed. J Merits of the Scottish School. Their proclaiming it as a rule, 1°, That the province of a preliminary or general Logic (Noology) — the ultimate laws, &c, of the human mind — should be sought out and established ; 2°, That once recog- nised and given, they should be accept- ed, to govern philosophy, as all other sciences. With regard to the first, the Scottish philosophers are not original. It is a perennis philosophia, gravitated towards * On the relation of the system of Fries to that of Bcid, see below, Note A, p. 70S, No. 95 ; and the rofercnees there given.— Ed, MEMORANDA FOR PREFACE. xvn even by those who revolted against it. (See Note A. ) The merit of the Scottish school is one only of degree, — that it 1b more consistent, more catholic, and em- bodies this permute philosophia more purely. [Its writers, however,] are them- selves peccant in details, and have not always followed out the spirit of their own doctrines. [With regard to the second,] Dr Reid and Mr Stewart not only denounce as absurd the attempt to demonstrate that the original data of Consciousness are for us the rule of what we ought to believe, that is, the criteria of a relative — human — subjective truth; but interdict as unphi- losophical all question in regard to their validity, as the vehicles of an absolute or objective truth. M. Jouffroy,* of course, coincides with the Scottish philosophers in regard to the former; but, as to the latter, he maintains, with Kant, that the doubt is legitimate, and, though he admits it to be insoluble, he thinks it ought to be enter- tained. Nor, on the ground on which they and he consider the question, am I disposed to dissent from his conclusion. But on that on which I have now placed it, I cannot but view the inquiry as in- competent. For what is the question in plain terms ? Simply, — Whether what our nature compels us to believe as true and real, be true and real, or only a consistent illusion ? Now this question cannot be philosophically entertained, for two rea- sons. 1°, Because there exists a pre- sumption in favour of the veracity of our nature, which either precludes or peremptorily repels a gratuitous supposi- tion of its mendacity. 2°, Because we have no mean out of Consciousness of testing Consciousness. If its data are found concordant, they must be presumed trustworthy; if repugnant, they are al- ready proved unworthy of credit. Un- less, therefore, the mutual collation of the primary data of Consciousness be held such an inquiry, it is, I think, mani- festly incompetent. It is only in the case of one or more of these original facts being rejected as false, that the question can emerge in regard to the truth of the others. But, in reality, on this hypothesis, the problem is already decided ; their character for truth is gone ; and all sub- sequent canvassing of their probability is profitless speculation. Kant started, like the philosophers in general, with the non-acceptance of the * (Earns do Reid, Preface, p. clxxxv.— Ed. deliverance of Consciousness, — that wo are immediately cognisant of extended objects. This first step decided the des- tiny of his philosophy. The external world, as known, was, therefore, only a phenomenon of the internal; and our knowledge in general only of self; the objective only subjective ; and truth only the harmony of thought with thought, not of thought with things; reality only a necessary illusion. It was quite in order, that Kant should canvass the veracity of all our primary beliefs, having founded his philosophy on the presumed falsehood of one ; and an in- quiry followed out with such consistency and talent, could not, from such a com- mencement, terminate in a different result.* Fiohte evolved this explicit idealism — Nihilism, f Following the phantom of the Absolute, Schelling rejected the lawof Contradiction, as Hegel that of Excluded Middle ; J with the result that, as acknowledged by the former, the worlds of common sense and of philosophy are reciprocally the converso of each other. Did the author not see that this is a reductio ad absurdum of phi- losophy itself ? For, ex hypothesi, philo- sophy, the detection of the illusion of our nature, shews the absurdity of nature; but its instruments are only those of this illusive nature. Why, then, is it not an illusion itself? The philosophy which relies on the data of Consciousness may not fulfil the condi- tions of what men conceit that a philo- sophy should be : it makes no pretension to any knowledge of the absolute — the unconditioned — but it is the only philo- sophy which is conceded to man below ; and if we neglect it, we must either re- nounce philosophy or pursue an ignis fa- tuus which will only lead us into quag- mires. § [Defects of the Scottish School.] Scottish school too exclusive — intoler- ant, not in spirit and intention, for Reid * Reprinted from Lectures on Metaphysics, vol. i. p. 399. From the reference below, p. 746 a, n. *, it appears that this question was intended to be discussed in the Preface. — En. t See below, p. 129, n. * and 796 b.— Ed. X See Lectures on Logic, vol. i. p. 90. — Ed. § In the MS. follow references to the two Scaligers, to Grotius, and to Cusa ; the last being, through Bruno, the father of the modern Philo- sophy of the Absolute. All these references are given in fall, Discussions, pp. 638-041, — Ed. Xvm MEMORANDA FOR PREFACE. and Stewart wore liberal — but from not taking high enough ground, and studying opinions with sufficient accuracy, and from a sufficiently lofty point of view. On the nature and domain of the philo- sophy of mind. Reid and Stewart do not lay it out pro- perly, though their practice is better than their precept. They do not take notice of the difference between mental and phy- sical inquiry — that the latter is mere induc- tive classification, the former more specula- tive, secerning necessary from contingent. But an element of thought being found necessary, there remains a further process — to ascertain whether it be, 1°, by nature or by education ; 2°, ultimately or deriva- tively necessary ; 3°, positive or negative. . . . . A law of nature is only got by general induction ; a law of mind is got by experiment — whether we can not think it; e. g. cause in objective and subjective phi- losophy. The progress of the two sciences not parallel — error of Stewart (Essays, p. xiii.*) An experimental analysis, but of differ- ent kinds, is competent to physical and mental science, besides the observation common to both. To mental, the trying what parts of a concrete thought or cog- nition can be thought away, what cannot. [Further developments supplementary to the philosophy of the Scottish school, as re- I by Reid and Stewart.] [A. On the Principle of Oom/mon Sense.] I would, with Leibnitz, t distinguish truths or cognitions into those of Fact, or of Perception, (external and internal), and those of Reason. The truths or cognitions of both classes rest on an ultimate and common ground of a primary and inexpli- cable belief. This ground may be called by the names of Common Sense, of Fun- damental or Transcendental Consciousness, * Coll. Works, vol. v. p. IS. " The order established in the intellectual world seems to be regulated by laws perfectly analogous to those which we trace among the phenomena of the material system; and in all our philosophical inquiries, (to whatever subject they may relate,) the progress of the mind is liable to be affected by the same tendency to a premature generalisa- tion." On this passage, there is the following marginal note in Sir W. Hamilton's copy: " Shew how this analogy is vitiated by the fact that the most general faots, being necessities of thought, are among the first established. Existence, the last in the order of induction, is the first in the order of ."—Ed. f Nouveanx Essais, L. iv. ch. 2 — Ed. of Feeling of Truth or Knowledge, of Na- tural or Instinctive Belief. This, in itself, is simply a fact, simply an experience, and is purely subjective and purely negative. It supports the validity of a proposition, only on the fact that I find that it is im- possible for me not to hold it for true, to suppose it therefore not true — without denying, in the one case, the veracity of consciousness ; and, in the other, the pos- sibility of thought; [without presuming] that I am necessitated to hold the false for the true, the unreal for the real, and therefore that my intelligent nature is radically mendacious. But this is not to be gratuitously presumed ; therefore the proposition must be admitted. But to apply it to the two classes of truths. I. Truths of Fact or of Perception (Ex- ternal and Internal.) Am I asked, for example, how I know that the series of phaenomena called the external world or the non-ego exists — I answer, that I know it by external Per- ception. But if further asked, how I know that this Perception is not an il- lusion — that what I perceive as the ex- ternal world, is not merely a particular order of phaenoniena pertaining to the in- ternal — that what I am conscious of as something different from me, is not merely self representing a not-self — I can only answer, that I know this solely inasmuch as I find that I cannot but feel, hold, or believe that what I perceive as not-self, is really presented in consciousness as not- self. I can, indeed, in this, as in the case of every other truth of Pact, imagine the possibility of the converse — imagine that what is given as a mode of not- self, may be in reality only a mode of self. But this only in imagining that my primary con- sciousness deceives me ; which is not to be supposed without a ground. Now, the conviction here cannot in propriety be called Reason, because the truth avouched by it is one only of Fact, and because the conviction avouching it is itself only ma- nifested as a Pact. It may, however, he well denominated Common Sense, Funda- mental or Transcendental Consciousness. Other examples may be taken from Me- mory and its reality, Personal Identity, &c, II. Truths of Reason. Again, if I am asked, how I know that every change must have its cause, that every quality must have its substance, that there is no mean between two contra- dictories, &c, I answer, that I know it by Reason, vovs — Reason or vovs being a name for the mind considered as the source, or as the complement, of first principles, axioms, native notions, kowoi or tprnmaX Zvvoiai. MEMORANDA FOR PREFACE. xlx But if further asked, how I know that Rea- son ib not illusive — that this, or that first principle may not be false — I can only an- swer, that I know it to be true, solely inas- much as I am conscious that I cannot but feel, hold, believe it to be true, seeing that I cannot even realise in imagination the possibility of the converse. Now, this last ground of conviction, in the conscious im- potence of conceiving the converse, is not, I think, so properly styled Reason, which is more of a positive character, as Common Sense, Fundamental Consciousness, &c. This is shewn in the quotations from Locke and Price. Note A, Testimonies, Nos. 51, 78. [The substance of these remarks on the Principle of Common Sense, has been already printed, in an abbreviated form, in Note A, p. 754. The present fragment, which has the appearance of being an earlier sketch of the same note, has been inserted in this place, as containing a somewhat fuller statement of an import- ant distinction, which is perhaps liable to be overlooked in the brief form in which it was previously published. Though not apparently designed for this Preface, it is sufficiently cognate in matter to the pre- ceding fragments, to be entitled to a place with them. The following fragment, which is marked " Preface," may be regarded as a continuation of the same subject, being a step towards that further analysis of the Truths of Reason, in relation to the Phi- losophy of the Conditioned, which the Author regarded as his peculiar addition to the philosophy of his predecessors. This analysis will be found further pursued in Notes H and T, and especially in the Philosophical Appendix to the Discussions. —Ed.] [B. Stages m the method of Mental Science.] Three degrees or stages in the method of mental science. 1°, When the mind is treated as matter, and the mere Baconian observation and induction applied. 2°, When the quality of Necessity is in- vestigated, and the empirical and neces- sary elements thus discriminated. (Here Reid is honourably distinguished even from Stewart, not to say Brown and other British philosophers. ) 3°, When the necessity is distinguished into two classes — the one being founded on a power or potency, the other upon an impoten ce of mind. Hence the Philosophy of the Conditioned. [Testimonies to the merits of the Scottish Philosophy, and of Seid as its founder.'] 1. — Poret. — Manuel de Philosophie par Auguste Henri Matthias, traduit de 1' Alle- mand sur la troisieme Edition, par M. II. Poret, Professeur suppleant a la Faculte des Lettres, et Professeur de Philosophie au College Rollin. Paris, 1837. Preface du Traducteur. — 'II suffit d'a- voir une idee de l'e'tat des §tudes en Prance pour reconnaitre que la philosophie e"cos- saise y est aujourd'hui naturalised. Nous la voyons defrayer a peu pres seule l'en- seignement de nos colleges; sa langue et ses doctrines ont passe" dans la plu- part des ouvrages elementaires qui se publient sur les matieres philosophiques ; sa me'thode severe et circonspecte a satisfait les plus difficiles et rassure' les plus de'fiants, et en meme temps Bon profond respect pour les croyances mo- rales et religieuses lui a concilia ceux qui reconnaissent la verity surtout a ses fruits. Les penseurs prevoyants qui so donnerent tant de soins pour l'introduire parmi nous ont eu a se f inciter du succes de lcur efforts. La seule apparition do cette philosophie si peu fastueuse suffit pour mettre a terre le sensualisme ; une doctrine artiflcielle dut s'evanouir devaut la simple exposition des faits ; le sens in- time fut re'tabli dans sa prerogative ; les elements a priori de l'intelligence, si ridi- culement honnis par Locke et son dcole, rentrerent dans la science dont on avait pretendu les bannir, et y reprirent leur place legitime. Cette espece de restaura- tion philosophique devait avoir ses conse- quences : des questions assoupies, mais non pas mortes, se re"veillerent ; les limites arbitrairement posees a la connaissanco disparurent ; la philosophie retrouva son domaine, et de nouveau les esprits s'effor- cerent de le conquerir. En general, le bienfait des doctrines ecoBsaises importdes en France, 9'a &i& d'affranchir les intelli- gences de tout prejuge' d'e"cole et de les remettre en presence de la re'alite'. Nul doute que ce ne fut la l'indispensable con- dition de tout progres ulterieur, et cette condition indispensable, elles l'ont remplie dans toute son e'tendue. Aujourd'hui meme qu'elles ont porte ces premiers fruits, les bons efl'ets de ces doctrines ne sont pas, nous le croyons, prSs de s'epuiser, et nous regarderions comme un echec a la prospeVitS des Etudes philosophiques tout ce qui tendrait a en contrarier l'influence.' 2. — Garnier. — Critique de la Philoso- phie de Thomas Reid, Paris, 1840. P. 112. — ' Demandez a ce philosophe une distribution mdthodique des materiaux MEMORANDA FOR PREFACE. qu'il a recueillis, une adroite induction qui des phenomenes nous conduise a un petit nombre de causes, vous ne trou- verez ni cette classification, ni cette ana- lyse. Ce n'dtait pourtant pas la tache la plus malaise'e ; et le de"pit de lui voir negliger ce facilo travail est ce qui nous a mis la plume a la main. Mais ces materi- aux innombrables, ces milliers de phe- nomenes si patiemment de"crits, faut-il les oublier? N'est-ce pas Reid qui nous a montre" a ne plus confondre les percep- tions des diffe'rents sens, et en particulier, celles de la vue et du toucher ? Malgre' quelques contradictions, n'est-ce pas chez lui seul qu'on peut recontrer une thebrie raisonnable de la perception ? Ou trouver une plus savante exposition de la memoire et des merveilles si varices qui presente la suite de nos conceptions? Ses essais sur l'abstraction, le jugement, et le rai- sonnement sont encore plus lumineux et plus instructifs que les memes chapitres dans l'admirable Logique de Port-Royal, et les savants solitaires ont partage" la faute de regard er ces operations de l'esprit comme les actes d'autant de facultes distinctes. Enfin, avec quel pro- fit et quel inte>et ne lit-on pas les cha- pitres sur le gout intellectuel, sur les affec- tions si varices qui se partagent notre ame, sur le sens du devoir et sur la morale? Avec touB ses diSfauts, l'ouvrage de Reid offrira longtemps encore la lecture la plus instructive pour l'esprit, la plus delicieuse pour le cosur, et la plus profitable pour la philosophie.' P. 118 'En presence des constructions fantastiques de l'Allemagne, j'aime mieux les mate"riaux epars de l'Ecosse. Thomas Reid est l'ouvrier laborieux, qui a peui- bloment extrait les blocs de la carriere, qui a faille" les mats et les charpentes : vi- enne l'architecte, il en construira des villes et des flottes. L'Allemand est l'entrepre- neur audacieux qui dans la hate de batir se contente de terre et de paille.' 3. — Remusat. — Essais de Philosophie, Paris 1842, t. i. p. 250.—' La philosophie de Reid nous parait un des plus beaux re"- sultats de la methode psychologique. Plus approf ondie, mieux ordonnfe, elle peut de- venir plus syste"matique et plus complete ; elle peut donuer a l'observation une forme plus rationnelle. Sans doute elle n'est pas tout la verite philosophique ; mais dans son ensemble elle est vraie, et nous croyons qu'elle doit dtre conside>ee par les ecoles modernes comme la philosophie elemen- taire de l'esprit humain. ' 4. — Thdeot. — Introduction a l'Etade du la Philosophie, Discours Preliminaire, t. i. p. lxiv, Speaking of Reid's Essays — ' L'erudition choisie ct varieo qu il a su y rgpandre, l'amour sincere de la verit6 qui s'y montre partout, et la dignity calme de l'expression en rendent la lecture extreme- ment attachante.' 5. — Cousin.— [Cours d'Histoire de la Philosophie Morale au dix-huitieme Siecle, seconde partie, publiee par MM. Danton et Vacherot, Paris, 1840], p. 241 sq.* ' There is a final merit in the doctrine of the Scottish philosopher, which it is impossible too highly to extol. He has done better than ruin the hypotheses which had shaken all the bases of human belief ; in fixing with precision the limits of science, he has destroyed for ever the spirit itself which had inspired them. The philosophy which Reid combated had not understood that there were facts inexpli- cable, facts which carry with them their own light ; and had therefore gone, in quest of a principle of explanation, into a foreign sphere. It is thus that to explain the phsenomena of perception, of mem- ory, of imagination, recourse was had to images from the external world ; the pha> nomena of the soul were represented as the effects of sensible impressions, them- selves resulting from a contact between the mind and the body. Reid has laid down the true criterium, in virtue of which we can always recognise the point at which an attempt at explanation ought to stop, when he says : — Facts simple and primi- tive are inexplicable. It is thus that he has cut short those hypotheses, those pre- sumptuous theories, which history has consigned for ever to the romances of Metaphysio. ' In the meanwhile, it remains for me to consider, whether the remedy be not excessive, and whether the philosophy of Reid, in ruining the metaphysical hypo- theses, has not proscribed the metaphysi- cal spirit itself. But before enteriug upon the question, it is requisite to pre- mise, that even if this be done by Reid, still there is nothing in the proceeding at which criticism ought to take offence. His mission was to proclaim the applica- tion of the experimental method to the philosophy of the human mind, on the ruins of the hypotheses which had issued from the Cartesian school ; this mission he has completely fulfilled, for he has purged philosophy, one after another, of the theory of ideas, of the desolating scepticism * This passage is given in a translation found among Sir W. Hamilton's papers. The other testimonies have been added from his extracts and ivRtcuccs. — Ed. MEMORANDA FOR PREFACE. xxi of Hume, of the idealism of Berkeley, of the demonstrations of Descartes ; he has thus made a tabula rasa. Were it then the fact, that the abuse of the metaphysical spirit, and the spectacle of the aberrations into which this spirit has betrayed the human mind, had carried Reid to pro- nounce its banishment from science, for this we ought no more seriously to re- proach him, than we should condemn Bacon for his proscription of the Syllog- ism, of which the Schoolmen had made so flagrant an abuse. My intention, there- fore, in touching on this delicate point, is, far less to evince the too empirical char- acter of the philosophy of Beid, than to relieve a great and noble science from the unjust contempt to which it has been exposed from the philosophers both of the school of Bacon and of the Scottish school. ' But let us first see, how far Reid's neglect of Metaphysic has extended. — Ac- cording to him, to explain a fact is to carry it up into a fact more simple ; so that the explanatory principle is of the same nature as the fact explained, nor, in our explanation of facts, is it ever neces- sary for us to transcend experience. I admit the truth of this definition for a certain number of the sciences which ought not to transgress the bounds of ob- servation : thus in Physics, in Natural His- tory, in Psychology even, the explanation of the fact can possess no other character, can propose no other aim. But I believe the human mind goes farther ; the ex- planation which consists in the connecting one fact to another more simple does not suffice for it, nor does it even recognise this as a veritable explanation. To ex- plain, to explicate, in the strict propriety of language, is to reduce that which is to that which ought to be, in other words, to connect a fact to a principle. Reid, therefore, in the view he takes of the explanation of facts, has banished from science the research of principles, of the necessary causes and reasons of things, — that is, precisely, metaphysical speculation. ' On the other hand, to distinguish philosophy from the sciences which hare nature for their object, he defines it — the science of the human mind; he thus con- siders philosophy as a science no less special than the others, which is only dis- criminated from them by the nature of its object, and which, moreover, has with them the same method and the same end. The same method : for, like the natural sciences, it observes ; only the facts which it observes are immaterial. The same end : for it proposes the discovery of laws, like the sciences of nature ; the only dif- ference lying in the nature of these laws. As to that general and synthetic science, which applies itself to all, and to which no matter comes amiss, which is distin- guished from other sciences, not by tho character of its object but by the elevated point of view from which it contemplates the universe of things, which styles itself philosophy of Nature, philosophy of Mind, philosophy of History, according to the limitation of the object which for the moment it considers, — of such a science Reid does not appear to have even sus- pected the existence. ' In fine, we ought not to forget that Reid is a partisan of the Baconian method, which he has extended from the sciences of nature to the science of mind. Now, as is well knowu, Bacon had a proud con- tempt of Metaphysic, and names it only to deride it, or to shew that in retaining the word, he rejects the thing. Accordingly, in his classification of the sciences, he reduces Metaphysic to the mere science of the immutable and universal forms of nature, that is to say, to a transcendental physics; while subsequently, in his Novum Organum, there is no mention of it at all. Reid, who inherited from Bacon his method, inherited likewise from him his contempt of Metaphysic; and, with Reid, the whole Scottish school. ' Once more I repeat, the reaction of the experimental philosophy, so much and so long oppressed by speculation, is excus- able in Reid as in Bacon, because on their part it was natural and almost necessary ; but in the present day, when this philoso- phy has everywhere triumphed over the obstacles which the spirit of system, the prejudices and the authority of the past, had accumulated in its path, — in the pre- sent day, when this philosophy in its turn oppresses Metaphysic, and would, if it could, exclude it from the domain of science, it may not be unimportant briefly to shew, that Metaphysic also has its titles, and its legitimate place in the cycle of human knowledge. ' In the first place, it is a very ancient science ; under definitions the most di- verse, it has always appeared as the science of principles. Until the eighteenth century, it has never for a moment quit- ted the philosophic stage, and on that stage has never ceased to occupy the most distinguished part. The reason of this preeminence was very simple ; for to Metaphysic was confided the task of re- solving the most extensive, arduous, and important problems : Metaphysic alone spoke of God and his attributes, of tho universe considered in its totality and ito MEMORANDA. FOR PREFACE. laws, of the human soul and of its destiny; Metaphysic alone shewed to each faculty the end in view for its activity, to the im- agination the ideal of the beautiful, to the will the ideal of the good, to the intelli- gence the ideal of the true. Since the erapirism of the last century, dominant in France and England, has relegated Metaphysic to the region of chimseras, science rarely agitates those mighty pro- blems, and if perchance it moots them, it does so with a timidity and weakness which make us regret that powerful im- pulse of the metaphysical genius which alone is competent to handle and resolve these formidable questions. Why then has it been repudiated by science? Is it only proper to generate magnificent ro- mances ? Is it that Metaphysic is without a basis ? ' To judge of it by the objections of its adversaries and by the unreflective en- thusiasm of its partisans, to judge of it especially by the strange forms in which imagination has been pleased to clothe it, it would seem that Metaphysic is a philo- sophy mysterious and almost superhuman, which descends from another world, and which has nothing in common with the positive and natural methods of science. There is nothing more false. Metaphysic, like the other sciences, has its roots in the nature of the mind. If the sciences of fact repose in observation, if the abstract sciences are founded upon reasoning, Me- taphysic has for its basis the conceptions of reason, as well pure as in combination with the data of experience. I say the conceptions of reason, which I distinguish, and which every observer of the acts of intelligence may distinguish, from the fan- tastic or arbitrary creations of imagination. When on occasion of an existence finite, contingent, relative, individual, attested by experience, I conceive the infinite, the necessary, the absolute, the universal ; when rising from the phenomena which the universe presents to my observation, I contemplate the great laws of this uni- verse, those laws which constitute the harmony of its movements, the order and the beauty of its plan ; when retiring within the limits of my proper nature, I connect the phenomena, so various and so mutable, in which it is manifested, to a principle, simple, identical, and immut- able in essence, — I neither imagine, nor dream, nor fabricate ; I conceive. My conception is an act of my mind, necessary and legitimate as the very simplest percep- tion. No intelligent being has a right to contest tho authority of any faculty whatever of intelligence, and it is lament- able to see the highest and divinest of its functions treated with contempt.' 6.— Jouffrot.— CEuvres Completes de Thomas Reid, Paris, 1836. PrSface, pp. cc. cci.— ' S'il est un service et un service eminent que les Ecossais aient rendu b, la philosophic, e'est assurement d'avoir etabli une fois pour toutes dans les esprits, et de maniere a ce qu'elle ne puisse plus en sortir, l'idee qu'il y a une science d'observation, une science de faits, a la maniere dont l'entendent les phyBiciens, qui a 1'esprit humain pour objet et le sens intime pour instrument, et dont le re - - sultat doit 6tre la determination des lois de 1'esprit, comme celui des sciences physiques doit etre la determination dea lois de la matiere. Les philosophes ecos- sais ont-ils eu les premiers cette idee! Non, sans doute, si par avoir une idee on entend simplement en e'mettre d'au- tres qui la contiennent ; a le prendre ainsi plusieurs philosophes l'avaient eue avant eux, et, pour ne citer que les plus ce'lebres, on la trouve dans Locke et dans Descartes. Mais si par inventer une idee on entend non pas seulement en concevoir le germe, mais la saisir en elle- meme dans toute sa ve'rite' et son ^ten- due, mais en voir la ported et les conse- quences, mais y croire, mais la pratiquer, mais la prtlcher, mais la mettre dans une telle lumiere qu'elle pe"netre dans tous lea esprits et qu'elle soit desormais acquise d'une maniere definitive a l'intelligence humaine, on peut dire avec v6rite' que, l'idee dont il s'agit, les Ecossais l'ont eue les premiers et qu'ils en sont les ve"ritables inventeurs. ' P. cciv.-ccvi. — ' C'est la en effet le vrai titre, le titre Eminent des philosophes dcos- sais a l'estirae de la postdrite et le principal service qu'ils aient rendu a la philosophie. C'est un fait qu'avant eux, ni l'idee de cette science ainsi nettement demelee, ni l'idee de la m^thode vraie a y appliquer, ni l'exemple d'une application rigoureuse de cette indthode, n'existaient; e'en est un autre que depuis eux tout cela existe et que c'est a eux qu'on le doit. Qu'ils soient trop restes dans les limites de cette science, et, faute d'en etre assez sortis, qu'ils n'en aient pas vu toute la portee, ni l'ensemble des liens qui, en y rattachant toutes les sciences philosophiques, en forment le point de depart et la racine de la moitid des connaissances humaincs, cela est vrai, et nous l'avons montre; que les vues historiques qui les ont conduits a 1 ide"e de cette science manquent souvent d'etendue et de justesse, et que dans la determination de la me"thode,des limites et des conditions de la science acme, ils MEMORANDA FOR PREFACE. n'aient pas toujours ni bien vu, ni aasez vu, c'cst ce qui est encore vTai et ce que nous avons ogalement montrd; mais tou- jours est-il que l'honneur do l'avoir crdee est a eux, et que, quand l'histoire voudra marquer l'epoque ou la science de l'esprit humain a veritablement etc? concue telle qu'elle doit l'etre, elle sera forcee d'indi- quer celle ou les philosophea ecosaaiB ont 6crit. ' Une seconde idee qui reste gravee dans l'esprit quand on a lu les philosophes ecossais, et dont on peut dire, comme de la prgce'dente, qu'ils l'ont mise au monde, quoique plusieurs philosophes, et Locke en dernier lieu, l'eussent indiqufe, c'est que la connaissance de l'esprit humain et de ses lois est la condition de solution de la plupart des questions dont la philo- sophie s'occupe, de maniere que pour 16- soudre ces questions il faut avant tout acquerir cette connaissance, et qu'elles ne peuvent etre resolues que par hypothese tant qu'on ne la possede pas. Nous avons montre" que cette idee n'e'tait que le germe d'une idee plus grande que les Ecossais n'ont saisie qu'a moitie', a savoir que toutes les sciences philosophiques dependent de la psychologie, parce que toutes les ques- tions qu'elles agitent viennent se resoudre dans la connaissance des phenomenes api- rituels, et que c'est la le caractere com- mun qui unit toutes ces sciences entre elles, qui en constitue l'unite, et les dis- tingue des sciences physiques. Nous avons ajoute que si les Ecossais a'etaient Aleves jusqu'a cette idee, a la gloire d'a- voir fondd la science de l'esprit humain ils auraient ajoute' celle d'avoir fixe' l'idee ;de la philosophie et d'avoir organise' cette moitil de la connaissance humaine. Mais si cette conception est restee imparfaite idans leur esprit, il n'en eBt pas moins vrai qu'elle s'y est suffisamment developpee >pour imprimer a la philosophie ecossaise ;une direction originale et qui est selon :nous celle-la mime que la philosophie doit ;suivre. Subordonner toute recherche phi- ilosopljique a la psychologie, sur ce fonde- jment que toute question philosophique a isa solution dans quelques lois de la nature ispirituelle, comme toute question physique fa la sienne dans quelques lois de la na- ture physique, voila en reality ce que les Ecossais ont fait, ot lc principe qui plane sur toute leur philosophie, qui l'anime, qui la dirige, et dont on resto peiidtro' quand on l'a fitudiee. La methode phi- losophique des Ecossais n'est autre chose qu'une consequence de ce principe; et non-seulement ils ont prouve" la veritC de ce principe pour un grand nombre de questions philosophiques et pour les plus importantes, mais ils l'ont constamment pratiqu^. ' Pp. ccvii., ccviii. — ' Avant et depuia les Ecossais aucun autre systerne n'offre cette construction de la science ; elle leur appar- tient en propre. et c'est la le second service qu'ils ont rendu a la philosophie. Ils ont f onde' la science de l'esprit humain, c'est lo premier; apres en avoir fixe' l'idee, ils ont fait de cette science le point de depart de la philosophie et sont venus chercher dans ses donnees la solution scieotifique de toute question, e'eat la le second. ' Une troisieme idee qui n'est moins importante ni moins propre aux Ecossais que lea pre'ee'dentes, c'est l'aasimilation complete des recherches philoaophiques et des recherches physiquea, fondee sur ce principe que les unes et les autres ont egalement pour objet la connaissance d'une partie des osuvres de Dieu, et qu'il n'y a pas deux manieres de connaitre les ceuvres de Dieu, mais une aeule, qui a'ap- plique a la solution des questions philo- sophiques comme a celle des questions physiquea.' P. ccxiii. — ' En prouvant cette aimili- tude, ils disaipent la superstitieuae ob- scurity qui entoure les recherches philoao- phiques; ils les ramenentaux aim plea con- ditions, a la simple nature, & la simple methode de toutea lea recherchea scientifi- ques ; ils montrent l'erreur constante des philosophes qui ont meconnu cette verite* ; ils expliquent par cette erreur la destinee mlaheureusedecesrechercheajilsrassurent ainsi lea esprits que cette destinee eloig- nait de s'en occuper, et les rappellent a la • philosophie en la mettant dans une voie nouvelle et cependant eprouvee, dans la grande voie qu'indiquent les loia de l'en- tendement, qu'ont auivie toutea lea sci- ences, et par laquelle l'esprit humain est arrive a toutes les verites qui font sa puis- sance et sa gloire.' ACCOUNT THE LIFE AND WRITINGS THOMAS RE ID, D.D., F.R.S.E., LATE PROFESSOR OF MORAL PHILOSOPHY IN THE UNIVERSITY OP liLASOOW. DUGALD STEWART, Esq., F.R SS L & E, PROFESSOR OF MORAL PHILOSOPHY IN THE UNIVERSITY OF EDINBURGH. f!EA!> AT DIFFERENT MEETINGS OF I'HE ROYAL SOCIETY OP EDINIiUKOH, pruusiiKD in lcoa ACCOUNT OF THE LIFE AND WRITINGS OF THOMAS REID D.D. SECTION I. PROM DR REID'S BIRTH TILL THE DATE OP HIS LATEST PUBLICATION. The life of which I am now to present to the Boyal Society a short account, although it fixes an era in the history of modern philosophy, was uncommonly barren of those incidents which furnish materials for biography — strenuously devoted to truth, to virtue, and to the best interests of man- kind, but spent in the obscurity of a learned retirement, remote from the pursuits of ambition, and with little solicitude about literary fame. After the agitation, however, of the political convulsions which Europe has witnessed for a course of years, the simple record of such a life may derive an interest even from its uniformity ; and, when contrasted with the events of the passing scene, may lead the thoughts to some views of human nature on which it is not ungrateful to repose. Thomas Reid, CD., late Professor of Moral Philosophy in the University of Glas- gow, was born, on the 26th of April 1710, it Strachan, in Kincardineshire, a country parish, situated about twenty miles from Aberdeen, on the north side of the Gram- pian mountains. His father, the Rev. Lewis Reid, was minister of this parish for fifty years. He tvas a clergyman, according to his son's iccount of him, respected by all who knew lim, for his piety, prudence, and benevo- ence ; inheriting from his ancestors (most >f whom, from the time of the Protestant istablishment, had been ministers of the Church of Scotland) that purity and sim- plicity of manners which became his station ; and a love of letters, which, without attract- ing the notice of the world, amused his leisure and dignified his retirement. For some generations before his time, a propensity to literature, and to the learned professions — a propensity which, when it has once become characteristical of a race, is peculiarly apt to be propagated by the influence of early associations and habits — may be traced in several individuals among his kindred. One of his ancestors, James Reid, was the first minister of Banchory- Ternan after the Reformation, and trans- mitted to four sons a predilection for those studious habits which formed his own hap- piness. He was himself a younger son of Mr Reid of Pitfoddels, a gentleman of a very ancient and respectable family in the county of Aberdeen. James Reid was succeeded as minister of Banchory by his son Robert. Another son, Thomas, rose to considerable distinc- tion, both as a philosopher and a poet ; and seems to have wanted neither ability nor inclination to turn his attainments to the best advantage. After travelling over Europe, and maintaining, as was the cus- tom of his age, public disputations in seve- ral universities, he collected into a volume the theses and dissertations which had been the subjects of his literary contests ; and also published some Latin poems, which may be found in the collection entitled, " Delilite Po'dlamm Scolorum." On his return to his native country, he fixed his residence in London, where he was ap- pointed secretary in the Greek and Latin tongues to King James I. of England," and lived in habits of intimacy with some * Whose fcnglish works he, along with the learned Patrick Voui'g, translated into Latin,— H. B 2 ACCOUNT OF THE Ml'E AND WHITINGS of the most distinguished characters of that period. Little more, I believe, is known of Thomas Reid's history, excepting that ho bequeathed to the Marischal College of Aberdeen a curious collection of books and manuscripts, with a fund for establishing a salary to a librarian- Alexander Reid, the third son, was physi- cian to King Charles I., and published several books on surgery and medicine. The fortune he acquired in the course of his practice was considerable, and enabled him (besitte many legacies to his relations and friends) to leave various lasting and honourable memorials, both of his benevo- lence and of his attachment to letters. A fourth son, whose name was Adam, translated into English Buchanan's His- tory of Scotland. Of this translation, which was never published, there is a manuscript copy in the possession of the University of Glasgow. A grandson of Robert, the eldest of these sons, was the third minister of Banchory after the Reformation, and was great- grandfather of Thomas Reid, the subject of this memoir." The particulars hitherto mentioned, are stated on the authority of some short memorandums written by Dr Reid a few weeks before his death. In consequence of a suggestion of his friend, Dr Gregory, he had reso'ved to amuse himself with col- lecting such facts as his papers or memory could supply, with respect to his life, and the progress of his studies ; but, unfortun- ately, before he had fairly entered on the subject, his design was interrupted by hip last illness. If he had lived to complete it, 1 might have entertained hopes of pre- senting to the public some details with respect to the history of his opinions and speculations on those important subjects to which he dedicated his talents — the most interesting of all articles in the biography of a philosopher, and of which it is to be lamented that so few authentic records are to be found in the annals of letters. All the information, however, which I have derived from these notes, is exhausted in the foregoing pages ; and I must content myself, ia the continuation of my narrative, with those indirect aids which tradition, and the recollection of a few old acquaint- ance, afford ; added to what I myself have learned from Dr Reid's conversation, or col- lected from a careful perusal of his writings. His mother, Margaret Gregory, was a daughter of David Gregory, Esq. of Kin- nairdie, in Banffshire, elder brother of James Gregory, the inventor of the reflect- ing telescope, and the antagonist of Huy- ghens. She was one of twenty-nine children ; the most remarkable of whom was David Gregory, Savilian Professor of Astronomy at Oxford, and an intimate friend of Sir Isaac Newton. Two of heryounger brothers were at the same time Professors of Mathe- matics— the one at St Andrew's, the other at Edinburgh— and were the first persons who taught the Newtonian philosophy in our northern universities. The hereditary worth and genius which have so long dis- tinguished, and which still distinguish, tlic descendants of this memorable family, are well known to all who have turned their attention to Scottish biography ; but it is not known so generally, that, through tlie female line, the same characteristical endow- ments have been conspicuous in various instances ; and that to the other monuments which illustrate the race of the Gregories, is to be added the Philosophy of Reid. With respect to the earlier part of Dr Reid's life, all that I have been able to learn amounts to this : — That, after two years spent at the parish school of Kincar- dine, he was sent to Aberdeen, where lie had the advantage of prosecuting his class- ical studies under an able and diligent teacher ; that, about the age of twelve or thirteen, he was entered as a student in Marischal College ; and that his master in philosophy for three years wns Dr George Turnbull, who afterwards attracted some degree of notice as an author ; particularly by a book entitled, " Principles of Moral Philosophy ;'' and by a voluminous treatise (long ago forgotten) on " Ancient Paint- ing."* The sessions of the College were, at that time, very short, and the educa- tion (according to Dr Reid's own account] slight and superficial. It does not appear, from the information which I have received, that he gave any early indications of future eminence. Hb industry, however, and modesty, were con- spicuous from his childhood ; and it was foretold of him, by the parish schoolmaster, who initiated him in the first principles o. learning, " That he would turn out to lie a man of good and well-wearing parts ;" a prediction which touched, not unhappily, on that capacity of " patient thought" which so peculiarly characterised his philo- sophical genius. His residence at the University was pro- longed beyond the usual term, in conse- quence of his appointment to the office » librarian, which had been endowed by one of his ancestors about a century before The situation was acceptable to him, as it afforded an opportunity of indulging his passion for study, and united the charrM of a learned society with the quiet of ai academical retreat. Note n OF THOMAS REID, D.D. During this period, he formed an intimacy with John Stewart, afterwards Professor of Mathematics in Marischal College, and author of " A Commentary on Newton's Quadrature of Curves." His predilection for mathematical pursuits was confirmed and strengthened bythis connection. I have often heard him mention it with much pleasure, while he recollected the ardour v. ith which they both prosecuted these fas- cinating studies, and the lights which they imparted mutually to each other, in their first perusal of the " Principia," at a time when a knowledge of the Newtonian dis- coveries was only to be acquired in the writings of their illustrious author. In 1736, Dr Eeid resigned his office of librarian, and accompanied Mr Stewart on iin excursion to England. They visited together London, Oxford, and Cambridge, and were introduced to the acquaintance of many persons of the first literary eminence. His relation to Dr David Gregory procured him a ready access to Martin Folkes, whose house concentrated the most interesting objects which the metropolis had to offer to his curiosity. At Cambridge he saw Dr Bentley, who delighted him with his learn- ing, and amused him with his vanity ; and enjoyed repeatedly the conversation of the blind mathematician, Saunderson — a pheno- menon in the history of the human mind to which he has referred more than once in his philosophical speculations. With the learned and amiable man who was his companion in this journey, he main- tained an uninterrupted friendship till 1766, when Mr Stewart died of a malignant fever. His death was accompanied with circum- stances deeply afflicting to Dr Eeid's sensi- bility; the same disorder proving fatal to his wife and daughter, both of whom were buried with him in one grave. In 1737, Dr Reid was presented, by the King's College of Aberdeen, to the living of New-Machar, in the same county ; but the circumstances in which he entered on his preferment were far from auspicious. The 'intemperate zeal of one of his predecessors, and an aversion to the law of patronage, had so inflamed the minds of his parishioners against him, that, in the first discharge of his clerical functions, he had not only to en- counter the most violent opposition, but was exposed to personal danger. His unwearied attention, however, to the duties of his pffice, the mildness and forbearance of his temper, and the active spirit of his humanity, Soon overcame all these prejudices ; and, Siot many years afterwards, when he was failed to a different situation, the same per- sons who had suffered themselves to be so ar misled as to take a share in the outrages tgainst him, followed him, on his departure, — '.villi their blessings and tears. Dr Eeid's popularity at New-Machar (as I am informed l>y the respectable clergy- man* who now holds that living) increased greatly after Mb marriage, in 1740, with Elizabeth, daughter of his uncle, Dr George Eeid, physician in London. The accom- modating manners of this excellent woman, and her good offices among the sick and necessitous, are still remembered with gra- titude, and so endeared the family to the neighbourhood, that its removal was re- garded as a general misfortune. The simple and affecting language in which some old men expressed themselves on this subject, in conversing with the present minister, deserves to be recorded : — " We fought ayainU Dr Eeid when he came, and would have fought for him when he went away." In some notes relative to the earlier part of his history, which have been kindly com- municated to me by the Eev. Mr Davidson, minister of Eayne, it is mentioned, as a proof of his uncommon modesty and diffi- dence, that, long after he became minister of New-Machar, he was accustomed, from a distrust in his own powers, to preach the sermons of Dr TMlotson and of Dr Evans. I have heard, also, through other channels, that he had neglected the practice of com- position to a more than ordinary degree in the earlier part of his studies. The fact is curious, when contrasted with that ease, perspicuity, and purity of style, which he afterwards attained. From some informa- tion, however, which has been lately trans- mitted to me by one of his nearest relations, I have reason to believe that the number of original discourses which he wrote while a country clergyman, was not inconsider- able. The satisfaction of his own mind was probably, at this period, a more powerful incentive to his philosophical researches, than the hope of being able to instruct the world as an author. But, whatever his views were, one thing is certain, that, during his residence at New-Machar, the greater part of his time was spent in the most intense study; more particularly in a careful exami- nation of the laws of external perception, and of the other principles which' form the groundwork of human knowledge. His chief relaxations were gardening and beta ny , to both of which pursuits he retained his attachment even in old age. A paper which he published in the Phi- losophical Transactions of the Eoyal Society of London, for the year 1748, affords some light with respect to the progress of liis speculations about this period. It is en- titled, " An Essay on Quantity, occasioned by reading a Treatise in which Simplo and Compound Ratios are implied to Virtue and * Tho lu.y wnii.im Stron.-icn. 6 ACCOUNT OF THE LIFE AND WRITINGS Merit ;" and Bhews plainly, by its contents, that, although he had not yet entirely re- linquished the favourite researches of his youth, he was beginning to direct his thoughts to other objects. The treatise alluded to in the title of this paper, was manifestly the " Inquiry into the Origin of our Ideas of Beauty and Vir- tue ;" by Dr Hutcheson of Glasgow. Ac- cording to this very ingenious writer, the moment of public good produced by an indi- vidual, depending partly on his benevolence, and partly onhis ability, the relation between these different moral ideas may be expressed in the technical form of algebraists, by say- ing that the first is in the compound pro- portion of the two others. Hence, Dr Hutcheson infers, that " the beneroLnee of an agent (which in this system is synony- mous with his moral merit) is proportional to a fraction, having the moment of good for the numerator, and the ability of the agent for the denominator." Various other examples of a similar nature occur in the same work ; and are stated with a gravity not altogether worthy of the author. It is probable that they were intended merely as illustrations of his general reasonings, not as media of investigation for the discovery of new conclusions ; but they appeared to Dr Reid to be an innovation which it was of importance to resist, on account of the ten- dency it might have (by confounding the evidence of different branches of science) to retard the progress of knowledge. The very high reputation which Dr Hutcheson then possessed in the universities of Scotland, added to the recent attempts of Pitcairn and Cheyne to apply mathematical reasoning to medicine, would bestow, it is likely, an in- terest on Dr Reid's Essay at the time of its publication, which it can scarcely be expected to possess at present. Many of the observations, however, which it contains, are acute and original ; and all of them are expressed with that clearness and precision so conspicuous in his subsequent composi- tions. The circumstance which renders a subject susceptible of mathematical consider- ation, is accurately stated ; and the proper province of that science defined in such a manner as sufficiently to expose the absur- dity of those abuses of its technical phrase- ology which were at that time prevalent. From some passages in it, there is, I think, ground for concluding that the author's reading had not been very extensive pre- vious to this period. The enumeration, in particular, which he has given of the differ- ent kinds of proper quantity, affords a proof that he was not acquainted with the re- fined yet sound disquisitions concerning the nature of number and of proportion, which had appeared, almost a century before, in the " Mathematical Lt/i:Liirco" of Dr li.ir- row ; nor with the remarks on the same subject introduced by Dr Clarke m one of his controversial letters addressed to Leibnitz. In the same paper, Dr Reid takes occa- sion to offer some reflections on the dispute between the Newtonians and Leibnitzians, concerning the measure of forces. The fundamental idea on which these reflections! proceed, is just and important ; and it leads to the correction of an error com- mitted very generally by the partisans of both opinions — that of mistaking a question concerning the comparative advantages of two definitions for a difference of statement with respect to a physical fact. It must, I think, be acknowledged, at the same time, that the whole merits of the controversy are not here exhausted ; and that the hon- ■ our of placing this very subtle and abstruse question in a point of view calculated to reconcile completely the contending parties, was reserved for M. D'Alembert. To have fallen short of the success which attended, the inquiries of that eminent man, on a subject so congenial to his favourite habits of study, will not reflect any discredit on Hit powers of Dr Reid's mind, in the judgment of those who are at all acquainted with the history of this celebrated discussion. In 175'2, the professors of King's Col- lege elected Dr Reid Professor of Philoso- phy, in testimony of the high opinion they had formed of his learning and abilities. Of the particular plan which he followed in his academical lectures, while he held this office, I have not been able to obtain any satisfactory account ; but the depart- ment of science which was assigned to him by the general system of education in that university, was abundantly extensive ; com- prehending Mathematics and Physics as well as Logic and Ethics. A similar system was pursued formerly in the other univer- sities of Scotland ; the same professor thai conducting his pupil through all those branches of knowledge which are now ap- propriated to different teachers. And when he happened fortunately to possess tta various accomplishments which distin- guished Dr Reid in so remarkable a degree, it cannot be doubted that the unity anJ comprehensiveness of method of which such academical courses admitted, must neces- sarily have possessed Important advantags over that more minute subdivision of lito ary labour which has since been introdui " But, as public establishments ought to afe, r themselves to what is ordinary, rather ftu to what is possible, it is not surprising tlul experience should have gradually suggested an arrangement more suitable to the narro« limits which commonly circumscribe hui~ gelnus. Sut.11 after Dr Reid's removal to A! OF THOMAS REID, D.D. di'cn, lie projected (in conjunction with his friend Dr John Gregory) a literary society, which subsisted for many years, and which seems to have had the happiest effects in awakening and directing that spirit of philo- sophical research which has since reflected so much lustre on the north of Scotland. The meetings of this society were held weekly ; and afforded the members (beside the advantages to be derived from a mutual communication of their sentiments on the common objects of their pursuit) an oppor- tunity of subjecting their intended publica- tions to the test of friendly criticism. The number of valuable works which issued, nearly about the same time, from individuals connected with this institution — more par- ticularly the writings of Reid, Gregory, Campbell, Beattie, and Gerard — furnish the best panegyric on the enlightened views of those under whose direction it was originally formed. Among these works, the most original and profound was unquestionably the " In- quiry into the Human Mind," published by Dr Reid in 1764. The plan appears to have been conceived, and the subject deeply medi- tated, by the. author long before; but it is doubtful whether his modesty would have ever permitted him to present to the world the fruits of his solitary studies, without the encouragement which he received from the general acquiescence of his associates in the most important conclusions to which he had been led. From a passage in the dedication, it would seem that the speculations which termi- nated in these conclusions, had commenced as early as the year 1739 ; at which period the publication of Mr Hume's " Treatise of Human Nature," induced him, for the first time, (as he himself informs us,) " to call in question the principles commonly received with regard to the human understanding." In his "Essays on the Intellectual Powers," he acknowledges that, in his youth, he had, without examination, admitted the esta- blished opinions on which Mr Hume's sys- tem of scepticism was raised ; and that it was the consequences which these opinions seemed to involve, which roused his suspi- cions concerning their truth. " If I may presume," says he, " to speak my own sen- timents, I once believed the doctrine of Ideas so firmly as to embrace the whole of Berke- ley's system along with it ; till, finding other consequences to follow from it, which gave me more uneasiness than the want of a ma- terial world, it came into my mind, more than forty years ago, to put the question, What evidence have I for this doctrine, that all the objects of my knowledge are ideas in my own mind ? From that time to the pre- sent, I have been candidly and impartiy,all B8 I think, seeking for the evidence of this principle ; but can find none, excepting the authority of philosophers." In following the train of Dr Reid's re- searches, this last extract merits attention, as it contains an explicit avowal, on his own part, that, at one period of his life, he had been led, by Berkeley's reasonings, to abandon the belief of the existence of matter. The avowal does honour to his candour, and the fact reflects no discredit on his saga- city. The truth is, that this article of the Berkleian system, however contrary to the conclusions of a sounder philosophy, was the error of no common mind. Considered in contrast with that theory of materialism which the excellent author was anxious to supplant, it possessed important advantages, not only in its tendency, but in its scientific consistency ; and it afforded a proof, wher- ever it met with a favourable reception, of an understanding superior to those casual associations which, in the apprehensions of most men, blend indissolubly the pheno- mena of thought with the objects of external perception. It is recorded as a saying of M. Turgot, (whose philosophical opinions in some important points approached very nearly to those of Dr Reid,*) that " he who had never doubted of the existence of matter, might be assured he had no turn for metaphysical disquisitions." As the refutation of Mr Hume's sceptical theory was the great and professed object of Dr Reid's " Inquiry," he was anxious, before taking the field as a controversial writer, to guard against the danger of misapprehend- ing or misrepresenting the meaning of his adversary, by submitting his reasonings to Mr Hume's private examination. With this view, he availed himself of the good offices of Dr Blair, with whom both he and Mr Hume had long lived in habits of friend, ship. The communications which he at first transmitted, consisted only of detached parts of the work ; and appear evidently, from a correspondence which I have per- used, to have conveyed a very imperfect idea of his general system. In one of Mr Hume's letters to Dr Blair, he betrays some want of his usual good humour, in looking forward to his new antagonist. " I wish," says he, " that the parsons would confine themselves to their old occupation of worry- ing one another, and leave philosophers to argue with temper, moderation, and good manners." After Mr Hume, however, had read the manuscript, he addressed himself directly to the Author, in terms so candid and liberal, that it would be unjust to his memory to withhold from the public so pleasing a memorial of his character : — " By Dr Blair's means I have been * See, in particular, the article " Fxietenoe" in the " Luicyclcipeuie." 8 ACCOUNT OF THE LIFE AND WRITINGS favoured with the perusal of your perform- ance, which I have read with great pleasure and attention. It is certainly very rare that a piece so deeply philosophical is wrote with so much spirit, and affords so much entertainment to the reader ; though I must still regret the disadvantages under which I read it, as I never had the whole perform- ance at once before me, and could not be able fully to compare one part with another. To this reason, chiefly, I ascribe some obscurities, which, in spite of your short analysis or abstract, still seem to hang over your system ; for I must do you the jus- tice to own that, when I enter into your ideas, no man appears to express himself with greater perspicuity than you do — a talent which, above all others, is requisite in that species of literature which you have cultivated. There are some objections which I would willingly propose to the chap- ter, ' Of Sight,' did I not suspect that they proceed from my not sufficiently under- standing it ; and I am the more confirmed in this suspicion, as Dr Blair tells me that the former objections I made had been derived chiefly from that cause. I shall, therefore, forbear till the whole can be before me, and shall not at present propose any farther difficulties to your reasonings. I shall only say that, if you have been able to clear up these abstruse and important subjects, instead of being mortified, I shall be so vain as to pretend to a share of the praise ; and shall think that my errors, by having at least some coherence, had led you to make a more strict review of my prin- ciples, which were the common ones, and to perceive their futility. " As I was desirous to be of some use to you, I kept a watchful eye all along over your style ; but it is really so correct, and so good English, that I found not anything worth the remarking. There is only one passage in this chapter, where you make use of the phrase hirvkr to do, instead of hinder from doing, which is the English one ; but I could not find the passage when I sought for it. You may judge how un- exceptionable the whole appeared to me, vhen I could remark so small a blemish. l beg my compliments to my friendly adver- saries, Dr Campbell and Dr Gerard ; and also to Dr Gregory, whom I suspect to be of the same disposition, though he has not openly declared himself such." Of the particular doctrines contained in Dr Reid's " Inquiry,'' I do not think it necessary here to attempt any abstract s nor, indeed, do his speculations (conducted, as they were, in strict conformity to the rules of inductive philosophizing) afford a subject for the same species of rapid out- line which is so useful in facilitating the study of a merely hypothet'cal theory. Their great object was to record and to classify the phenomena which the operations of the human mind present to those who reflect carefully on the subjects of their consciousness ; and of such a history, it is manifest that no abridgement could be offered with advantage. Some reflections , on the peculiar plan adopted by the author, 1 and on the general scope of his researches in this department of science, will after- wards find a more convenient place, when I shall have finished my account of his subse- quent publications. The idea of prosecuting the study of the human mind, on ■■*■ plan analagous to that which had been so successfully adopted in physics by the followers of Lord Bacon, if not first conceived by Dr Reid, was, at least, first carried successfully into execution in his writings. An attempt had, long before, been announced by Mr Hume, in the title- page of his " Treatise of Human Nature," to introduce the experimental method of reasoning into moral subjects ; and some admirable remarks are made in the intro- duction to that work, on the errors into which his predecessors had been betrayed by the spirit of hypothesis ; and yet it is now very generally admitted, that the whole of his own system rests on a principle for which there is no evidence but the authority of philosophers ; and it is certain that, in no part of it has he aimed to investigate, by a systematical analysis, those general prin- ciples of our constitution which can alone afford a synthetical explanation of its com- plicated phenomena. I have often been disposed to think that Mr Hume's inattention to those rules of philoso- phizing which it was his professed intention J to exemplify, was owing, in part, to some indistinctness in his notions concerning their import. It does not appear that, in the earlier part of his studies, he had paid much attention to the models of investigation ex- hibited in the writings of Newton and of his successors ; and that he was by no means aware of the extraordinary merits of Bacon as a philosopher, nor of the influence which his writings have had on the subse- quent progress of physical discovery, is demonstrated by the cold and qualified encomium which is bestowed on his genius in one of the most elaborate passages of the " History of England." In these respects, Dr Reid possessed important advantages ; familiarized, from his early years, to those experimental:? inquiries which, in the course of the two* last centuries, have exalted natural philo- sophy to the dignity of a science, and determined strongly, by the peculiar bent of his genius, to connect every step in tin progress of discovery with the history of the Iranian mind. The influence of the 'eneral OF THOMAS REID, D. D. 9 views opened in the " Novum Organon" may be traced in almost every page of his writings ; and, indeed, the circumstance by which these are so strongly and character- istically distinguished, is, that they exhibit the first systematical attempt to exemplify, in the study of human nature, the same plan of investigation which conducted Newton to the properties of light, and to the law of gravitation. It is from a steady adherence to this plan, and not from the superiority of his inventive powers, that he claims to himself any merit as a philosopher ; and he seems even willing (with a modesty approaching to a fault) to abandon the praise of what is commonly called genius, to the authors of the systems which he was anxious to refute. " It is genius," he ob- serves in one passage, " and not the want of it, that adulterates philosophy, and fills it with error and false theory. A creative imagination disdains the mean offices of digging for a foundation, of removing rub- bish, and carrying materials : leaving these servile employments to the drudges in science, it plans a design, and raises a fa- bric. Invention supplies materials where they are wanting, and fancy adds colouring and every befitting ornament. The work pleases the eye, and wants nothing but solidity and a good foundation. It seems even to vie with the works of nature, till some succeeding architect blows it into ruins, and builds as goodly a fabric of his own in its place." " Success in an inquiry of this kind," he observes farther, " it is not in human power to command ; but perhaps it is possible, by caution and humility, to avoid error and delusion. The labyrinth may be too intri- cate, and the thread too fine, to be traced through all its windings ; but, if we stop where we can trace it no farther, and secure the ground we have gained, there is no harm done ; a quicker eye may in time trace it farther." The unassuming language with which Dr Reid endeavours to remove the preju- dices naturally excited by a new attempt to philosophize on so unpromising, and hitherto so ungrateful a subject, recalls to our recol- lection those passages in which Lord Bacon — filled as his own imagination was with the future grandeur of the fabric founded by his hand — bespeaks the indulgence of his readers, for an enterprise apparently so hopeless and presumptuous. The apology he offers for himself, when compared with the height to which the structure of physical knowledge has since attained, may perhaps have some effect in attracting a more gene- ral attention to pursuits still more im- mediately interesting to mankind ; and, at any rate, it forms the best comment on the prophetic suggestions in which Dr Reid occasionally indulges himself concerning the future progress of moral speculation : — " Si homines per tanta annorum spatia viam veram invcniendi et colendi scientias tenuissent, nee tamen ulterius progredi po- tuissent, audax procul dubio et temeraria foret opinio, posse rem in ulterius provehi. Quod si in via ipsa erratum sit, atque homi- num opera in iis consumpta in quibus minime oportebat, sequitur ex eo, non in rebus ipsis dimcultatem oriri, quae potestatis nos- tras non sunt ; sed inintellectu humano, ej us- que usu et applicatione, quse res remedium et medicinam suscipit."* — "De nobis ipsis silemus : de re autem quse agitur, petimus ; Ut homines earn non opinionem, sed opus esse cogitent ; ac pro certo habeant, non sectse nos alicujus, aut placiti, sed utilitatis et amplitudinis humanae fundamenta moliri. Praeterea, ut bene sperent ; neque Instau- rationem nostram ut quiddam infinitum et ultra mortale fingant, et animo concipiant ; quum revera sit infiniti erroris finis et ter- minus legitimus."-)- The impression produced on the minds of speculative men, by the publication of Dr Reid's "Inquiry," wasfully asgreatas could be expected from the nature of his under- taking. It was a work neither addressed to the multitude, nor level to their compre- hension ; and the freedom with which it canvassed opinions sanctioned by the highest authorities, was ill calculated to conciliate the favour of the learned. A few, however, habituated, like the author, to the analytical researches of the Newtonian school, soon perceived the extent of his views, and re- cognised in his pages the genuine spirit and language of inductive investigation. Among the members of this University, Mr Fergu- son was the first to applaud Dr Reid's success ; warmly recommending to his pu- pils a steady prosecution of the same plan, as the only effectual method of ascertaining the general principles of the human frame ; and illustrating, happily, by his own pro- found and eloquent disquisitions, the appli- cation of such studies to the conduct of the understanding and to the great concerns of life. I recollect, too, when I attended (about the year 1771) the lectures of the late Mr Russell, to have heard high encomiums on the philosophy of Reid, in the course of those comprehensive discussions concerning the objects and the rules of experimental science, with which he so agreeably diversi- fied the particular doctrines of physics. Nor must I omit this opportunity of paying a tribute to the memory of my old friend, Mr Stevenson, then Professor of Logic ; whose candid mind, at the age of seventy, gave a welcome reception to a system subversive of the theories which he had taught for Nov, Cr{;. 91. -f Iiibtaur. Mag — Tin-fat. 10 ACCOUNT OF THE LIFE AND WRITINGS forty years ; and whose zeal for the ad- vancement of knowledge prompted him, when his career was almost finished, to undertake the laborious task of new-model- ling that useful compilation of elementary instruction to which a singular diffidence of his own powers limited his literary exer- tions. It is with no common feelings of respect and of gratitude, that I now recall the names of those to whom I owe my first attach- ment to tHfese studies, and the happiness of a liberal occupation superior to the more aspiring aims of a servile ambition. From the University of Glasgow, Dr Reid's " Inquiry" received a still more substantial testimony of approbation ; the author having been invited, in 1703, by that learned body, to the Professorship of Moral Philosophy, then vacant by the resignation of Mr Smith. The preferment was, in many respects, advantageous ; affording an income considerably greater than he enjoyed at Aberdeen; and enabling him to concentrate to his favourite objects, that attention which had been hitherto dis- tracted by the miscellaneous nature of his academical engagements. It was not, how- ever, without reluctance, that he consented to tear himself from a spot where he had so long been fastening his roots ; and, much as he loved the society in which he passed the remainder of his days, I am doubtful if, in his mind, it compensated the sacrifice of earlier habits and connections. Abstracting from the charm of local attachment, the University of Glasgow, at the time when Dr Reid was adopted as one of its members, presented strong attrac- tions to reconcile him to his change of situation. Robert Simson, the great re- storer of ancient geometry, was still alive ; and, although far advanced in years, pre- served unimpaired his ardour in study, his relish for social relaxation, and his amusing singularities of humour. Dr Moor com- bined, with a gaiety and a levity foreign to this climate, the profound attainments of a scholar and of a mathematician. In Dr Black, to whose fortunate genius a new world of science had just opened, Reid acknowledged an instructor and a guide ; and met a simplicity of manners congenial to his own. The Wilsons (both father and son) were formed to attach his heart by the similarity of their scientific pursuits, and an entire sympathy with his views and sen- timents. Nor was he less delighted with the good-humoured opposition which his opinions never failed to encounter in the acuteness of Millar — then in the vigour of youthful genius, and warm from the lessons of a different school. Dr Leechman, the friend and biographer of Hutcheson, was the official head of the College ; and added the weight of a venerable name to the repu. tation of a community which he had oncn adorned .in a more active station.* Animated by the zeal of such associates, and by the busy scenes which his new resi- dence presented in every department of useful industry, Dr Reid entered on his functions at Glasgow with an ardour not common at the period of life which he had now attained. His researches concerning the human mind, and the principles of morals, which had occupied but an incon- siderable space in the wide circle of science allotted to him by his former office, were, extended and methodized in a course which employed five hours every week, during six months of the year ; the example of his illustrious predecessor, and the prevailing topics of conversation around him, occa- sionally turned his thoughts to commercial politics, and produced some ingenious essays on different questions connected with trade, which were communicated to a private society of his academical friends ; his early passion for the mathematical sciences was revived by the conve sation of Simson, Moor, and the Wilsons ; and, at the age of fifty-five, he attended the lectures of Black, with a juvenile curiosity and enthusiasm. As the substance of Dr Reid's lectures at Glasgow (at least of that part of them which was most important and original) has been since given to the public in a more improvod form, it is unnecessary for me to enlarge on the plan which he followed in the discharge of his official duties. I shall therefore only observe, that, beside his spe- culations on the intellectual and active powers of man, and a system of practi- cal ethics, his course comprehended some general views with respect to natural juris- prudence, and the fundamental principles of politics. A few lectures on rhetoric, which were read, at a separate hour, to a more advanced class of students, formed a volun- tary addition to the appropriate functions of his office, to which it is probable he was prompted, rather by a wish to supply what was then a deficiency in the established course of education, than by any predilec- tion for a branch of study so foreign to his ordinary pursuits. The merits of Dr Reid as a public teacher were derived chiefly from that rich fund of original and instructive philosophy which is to be found in his writings, and from his unwearied assiduity in inculcating principles winch he conceived to be of essential import- ance to human happiness. In his elocution and mode of instruction, there was nothing Peculiarly attractive. He seldom, if ever § indulged himself in the warmth of exS pore discourse ; nor was his manner of Note C. OF THOMAS RE1D, D.D. 11 reading calculated to increase the effect of what he had committed to writing. Such, however, was the simplicity and perspicuity of his style, such the gravity and authority of his character, and such the general in- terest of his young hearers in the doctrines which he taught, that, by the numerous audiences to which his . instructions were addressed, ho was heard uniformly with the most silent and respectful attention. On this subject, I speak from personal know- ledge ; having had the good fortune, during a considerable part of winter 1772, to be one of his pupils. It does not appear to me, from what I am now able to recollect of the order which he observed in treating the different parts of his subject, that he had laid much stress on systematical arrangement. It is pro- bable that he availed himself of whatever materials his private inquiries afforded, for his academical compositions, without aiming at the merit of combining them into a whole, by a comprehensive and regular design — an undertaking to which, if I am not mistaken, the established forms of his university, consecrated by long custom, would have presented some obstacles. One thing is certain, that neither he nor his immediate predecessor ever published any general pr... spectus of their respective plans, nor any heads or outline* to assist their students in tracing the trains of thought which suggested their various transitions. The interest, however, excited by such details as these, even if it were in my power to render them more full and satisfactory, must necessarily be temporary and local ; and I, therefore, hasten to observations of a more general nature, on the distinguishing characteristics of Dr Reid's philosophical genius, and on the spirit and scope of those researches which he has bequeathed to posterity concerning the phenomena and laws of the human mind. In mentioning his first performance on this subject, I have already anticipated a few remarks which are equally applicable to his subsequent publications ; but the hints then suggested were too slight to place in so strong a light as I cculd wish the peculiarities of that mode of investigation which it was the great object of his writings to recommend and to exemplify. His own anxiety to neglect nothing that might contribute to its farther illustration induced him, while his health and faculties were yet entire, to withdraw from his public labours, and to devote himself, with an undivided attention, to a task of more extensive and permanent utility. It was in the year 1781 that he carried this design into execution, at a period of life (for he was then upwards of seventy) when the infirmities of age might be supposed to account sufficiently for his retreat ; but when, in fact, neither the vigour of his mind nor of his body seemed to have suffered any injury from time. The works which he published not many years afterwards, afford a sufficient proof of the assiduity with which he had availed himself of his literary leisure — his " Essays on tlio Intellectual Powers of Man" appearing in 1785, and those on the " Active Powers" in 1788. As these two performances are, both of them, parts of one great work, to which his " Inquiry into the Human Mind" may be regarded as the introduction, I have re- served for this place whatever critical reflec- tions I have to offer on his merits as an author ; conceiving that they would be more likely to produce their intended effect, when presented at once in a connected form, than if interspersed, according to a chronological order, with the details of a biographical narrative. SECTION II. OBSERVATION'S ON THE SPIRIT AND SCOPE OP mi reid's philosophy. I have already observed that the dis- tinguishingfeatureof Dr Reid's philosophy, is the systematical steadiness with which he has adhered in his inquiries, to that plan of investigation which is delineated in the " Novum Organon," and which has been so happily exemplified in physics by Sir Isaac Newton and his followers. To recommend this plan as the only effectual method of enlarging our knowledge of nature, was the favourite aim of all his studies, and a topic on which he thought he could not enlarge too rnuch, in conversing or corresponding with his younger friends. In a letter to Dr Gregory, which I have perused, he particu- larly congratulates him upon his acquaint- ance with Lord Bacon's works ( adding, " I am very apt to measure a man's under- standing by the opinion he entertains of that author." It were perhaps to be wished that he had taken a little more pains to illustrate the fundamental rules of that logic the value of which he estimated so highly ; more especially, to point out the modifications with which it is applicable to the science of mind. Many important hints, indeed, con- nected with this subject, may be collected from different parts of his writings ; but I am inclined to think that a more ample discussion of it, in apreliminary dissertation, might have thrown light on the scope of many of his researches, and obviated some of the most plausible objections which have boon stated to his conclusions. 12 ACCOUNT OF THE LIFE AND WRITINGS It is not, however, my intention at pre- sent to attempt to supply a desideratum of S" great a magnitude — an undertaking which, I trust, will find a more convenient place, in the farther prosecution of those speculations with respect to the intellectual powers which I have already submitted to the public. The detached remarks which lollow, are offered merely as a supplement to what I have stated concerning the nature and object of this branch of study, in the Introduction to the " Philosophy of the Human Mind." The influence of Bacon's genius on the subsequent progress of physical discovery, has been seldom fairly appreciated — by some wiiters almost entirely overlooked, and by others considered as the sole cause of the reformation in science which has since taken place. Of these two extremes, the latter certainly is the least wide of the truth ; for, in the whole history of letters, no other individual can be mentioned, whose exer- tiona have had so indisputable an effect in forwarding the intellectual progress of man- kind. On the other hand, it must be ac- knowledged, that, before the era when Bacon appeared, various philosophers in different parts of Europe had struck into the right path ; and it may perhaps be doubted whether any one important rulewith respect to the true method of investigation be con- tained in his works, of which no hint can be traced in those of his predecessors. His great merit lay in concentrating their feeble and scattered lights ; fixing the attention of philosophers on the distinguishing cha- racteristics of true and of false scienoe, by a felicity of illustration peculiar to himself, seconded by the commanding powers of a bold and figurative eloquence. The method of investigation which he recommended had been previously followed in every instance in which any solid discovery had been made with respect to the laws of nature ; but it had been followed accidentally and without any regular, preconceived design ; and it was reserved for him to reduce to rule and method what others had effected, either fortuitously, or from some momentary glimpse of the truth. It is justly observed by Dr Reid, that " the man who first dis- covered that cold freezes water, and that heat turns it into vapour, proceeded on the same general principle by which Newton discovered the law of gravitation and the properties of light. His ' Reguhe Philo- sophandi' are maxims of commonsense, and are practised every day in common life; and he who philosophizes by other rules, either concerning the material system or concerning the mind, mistakes his aim.'* These remarks are not intended to detract from the just glory of Bacon ; for they apply to ail those, without exception, who have systematized the principles of any of the arts. Indeed, they apply less forcibly to him than to any other philosopher whose studies have been directed to objects analo- gous to his ; inasmuch as we know of no art of which the ru es have been reduced successfully into a didactic form, when the art itself was as much hV infancy as expe- rimental philosophy was when Bacon wrote. Nor must it be supposed that the utility was small of thus attempting to systematize the accidental processes of unenlightened ingenuity, and to give to the noblest exer- tions of human reason, the same advan- tages of scientific method which have contributed so much to insure the success of genius in pursuits of inferior importance. The very philosophical motto which Rey- nolds has so happily prefixed to his "Academical Discourses," admits, on this occasion, of a still more appropriate appli- cation : — " Omnia fere quae prseceptis con- tinentur ab ingeniosis hominibus fiunt ; sed casu quodam magis quam scientia. Ideoque doctrina et animadversio adhibenda est, ut ea quae iiiterdum sine ratione nobis occur- runt, semper in nostra protestate sint ; et quoties res postulaverit, a nobis ex praepa- rato adhibeantur." But, although a few superior minds seem to have been, in some measure, predisposed for that revolution in science which Bacon contributed so powerfully to accomplish, the case was very different with the great majority of those who were then most dis- tinguished for learning and talents. His views were plainly too advanced for the age in which he lived ; and, that he was sen- sible of this himself, appears from those remarkable passages in which he styles himself " the servant of posterity," and " bequeaths his fame to future times." Hobbes, who, in his early youth, had enjoyed his friendship, speaks, a consider- able time after Bacon's death, of experi- mental philosophy, in terms of contempt ; influenced, piobably, not a little by the tendency he perceived in the inductive method of inquiry, to undermine the found- ations of that fabric of scepticism which it was the great object of his labours to rear. Nay, even during the course of the last century, it has been less from Bacon's own speculations, than from the examples of sound investigation exhibited by a few emi- nent men, who professed to follow him as their guide, that the practical spirit of his writings has been caught by the multitude oi physical experimentalists over Europe i truth and gsod sense descending gradually, in this as in other instances, by the force of imitation and of early habit, from the higher orders of intellect to the lower In ^me parts of the Continent, more 'espe- cully, the circulation of Bacon's philoso. OF THOMAS ItEID, D. D. 13 phical works has been surprisingly slow. It is doubtful whether Des Cartes himself ever perused them ;* and, as late as the year 1759, if we may credit Montucla, they were very little known in Prance. The introductory discourse prefixed by D'Alem- bert to the " Encyclopedie," first recom- mended them, in that country, to general attention. The change which has taken place, dur- ing the two last centuries, in the plan of physical research, and the success which has so remarkably attended it, could not fail to suggest an idea, that something analogous might probably be accomplished at a future period, with respect to the phenomena of the intellectual world. And, accordingly, various hints of this kind may be traced in different authors, since the era of Newton's discoveries. A memorable instance occurs in the prediction with which that great man concludes his " Optics :" — " That, if natural philosophy, in all its parts, by pursuing the inductive method, shall at length be perfected, the bounds of moral philosophy will also be enlarged." Similar remarks may be found in other publications ; particularly in Mr Hume's " Treatise of Human Nature," where the subject is enlarged on with much ingenuity. As far, however, as I am able to judge, l5r Reid was the first who conceived justly and clearly the analogy between these two dif- ferent branches of human knowledge ; de- fining, with precision, the distinct provinces of observation and reflection,-)- in furnish- ing the data of all our reasonings concerning matter and mind ; and demonstrating the necessity of a careful separation between the phenomena which they respectively exhibit, while we adhere to the same mode of philo- sophizing in investigating the laws of both. That so many philosophers should have thus missed their aim, in prosecuting the study of the human mind, will appear the less surprising when we consider in how many difficulties, peculiar to itself, this • This is a mistake, which it is the more requisite to correct, because Mr Stewart's authority in histori- cal points is, in consequence of hishabi'ual accuracv, de>ervedly high. It is repeated, if I recollect aright, in more articulate terms, in the " Dissertation on the Proeressnf Metaphysical Philosophy." Des Cartes, in three or four passages ot bis " Letters," makes honourable menion of Bacon and his method; his works he seems notonly to have perused but studied There is, however, no reason to suppose that Des Car. res was acquainted with the writings of his great predecessor in the early part of bis life.; and his own views in philosophy were probably not affected by this influence. Mr Stewart, likewise, greatly under- rates hV influence of the Haconian writings in gene. ral, previous to the recommendation of D'AIem- bert. On this subject, the reader is referred to a valuable paper by Professor Napier on the " Scope anrj Influence pf the Baconian Philosophy," in the Tfansactions-of the Royal Society of Edinburgh. — H . + See a note on Reid's Mxth " Essay on the Intel. Jectual Powers," chap l.»and of theorhjinal edition, p. 517.— H science is involved. It is sufficient .it present to mention those which arise from the metaphorical origin of all the words which express the intellectual phenomena ; from the subtle and fugitive nature of the objects of our reasonings ; from the habits of inattention we acquire, in early life, to the subjects of our consciousness ; and from the prejudices which early impressions and asso- ciations create to warp our opinions. It must be remembered, too, that, in the science of mind, (so imperfectly are its logi- cal rules as yet understood !) we have not the same checks on the abuses of our rea- soning powers which serve to guard us against error in our other researches. In physics, a speculative mistake is abandoned when contradicted by facts which strike the senses. In mathematics, an absurd or inconsistent conclusion is admitted as a demonstrative proof of a faulty hypothesis. But, in those inquiries which relate to the principles of human nature, the absurdities and inconsistencies to which we are led by almost all the systems hitherto proposed, instead of suggesting corrections and im- provements on these systems, have too frequently had the effect of producing scepticism with respect to all of them alike. How melancholy is the confession of Hume ! — " The intense view of these manifold contradictions and imperfections in human reason, has so wrought upon me, and heated my brain, that I am ready to reject all belief and reasoning, and can look upon no opinion even as more prob- able or likely than another." Under these discouragements to this branch of study, it affords us some comfort to reflect on the great number of important facts with respect to the mind, which are scattered in the writings of philosophers. As the subject of our inquiry here lies within our own breast, a considerable mix- ture of truth may be expected even in those systems which are most erroneous ; not only because a number of men can scarcely be long imposed on by a hypothesis which is perfectly groundless, concerning the ob- jects of their own consciousness, but because it is generally by an alliance with truth, and with the original principles of human nature, that prejudices and associations produce their effects. Perhaps it may even oe affirmed, that our progress in this re- search depends less on the degree of our industry and invention, than on our saga- city and good sense in separating old dis- coveries from the errors which have bet n blended with them ; and on that candid and dispassionate temper that may prevent us from being led astray by the love of novelty, or the affectut'on of singularity. In this respect, the science of mind pos- sesses a very important advantage over 11 ACCOUNT OF THE LIFE AND WRITINGS tliat which relates to the laws of the mate- rial world. The former has been culti- vated with more or less success in all ages and countries : the facts which serve as the basis of the latter have, with a very few exceptions, been collected durtngtthe course of the two last centuries. An observation similar to this is applied to systems of ethics by Mr Smith, in his account of the theory of Mandeville ; and the illustration ho gives of it may be extended with equal propriety to the science of mind in general : — " A system of natural philosophy," he remarks, " may appear very plausible, and be, for a long time, very generally received in the world, and yet have no foundation in nature, nor any sort of resemblance to the truth. But it is otherwise with systems of moral philosophy. When a traveller gives an account of some distant country, he may impose upon our credulity the most ground- less and absurd fictions as the most certain matters of fact ; but when a person pretends to inform us of what passesin our neighbour- hood, and of the affairs of the very parish we live in — though here, too, if we are so careless as not to examine things with our own eyes, he may deceive us in many re- spects — yet the greatest falsehoods which he imposes on us must bear some resem- blance to the truth, and must even have a, considerable mixture of truth in them.'' These considerations demonstrate the es- sential importance, iu this branch of study, of forming, at the commencement of our inquiries, just notions of the criteria of true and false science, and of the rules of philoso- phical investigation. They demonstrate, at the same time, that an attention to the rules of philosophizing, as they are exemplified in the physical researches of Newton and his fol- lowers, although the best of all preparations for an examination of the mental phenomena, is but one of the steps necessary to insure our success. On an accurate comparison of the two subjects, it might probably appear, that, after this preliminary step has been gained, the most arduous part of the process still remains. One thing is certain, that it is not from any defect in the power of ratio- cination or deduction, that our speculative errors chiefly arise — a fact of which wc have a decisive proof in the facility with which most students may be taught the mathematical and physical sciences, when compared with the difficulty of leading their minds to the truth, on questions of morals and politics. The logical rules which lay the foundation of sound and useful conclusions concerning the laws of this internal world, although not altogether overlooked by Lord Bacon, were plainly not the principal object of his work ; and what he has written on the sub- ject, consists chiefly of detached hints dropped casually in the course of other speculations. A comprehensive view of the sciences and arts dependent on the philosophy of the human mind, exhibiting the relations whick they bear to each other, and to the general system of human knowledge, would form a natural and useful introduction to the study of these logical principles ; but such a view remains still a desideratum, after all the advances made towards it by Bacon and D'Alembert. Indeed, in the present im- proved state of things, much is wanting to complete and perfect that more simple part of their intellectual map which relates to the material universe. Of the inconsider- able progress hitherto made towards a just delineation of the method to be pursued in studying the mental phenomena, no other evidence is necessary than this, That the sources of error and false judgment, so pe- culiarly connected, in consequence of the association of ideas, with studies in which our best interests are immediately and deeply concerned, have never yet been investigated with such accuracy as to afford effectual aid to the student, in his attempts to coun- teract their influence. One of these sources alone — that which arises from the imper- fections of language — furnishes an exceptioD to the general remark. It attracted, fortu- nately, the particular notice of Locke, whose observations with respect to it, compose, perhaps, the most valuable part of his philo- sophical writings; and, since the time of Condillac, the subject has been still more deeply analyzed by others. Even on this article, much yet remains to be done ; but enough has been already accomplished to j ustify the profound aphorism in which Bacon pointed it out to the attention of his follow- ers : — " Credunt homines rationem suam verbis imperare ; sed fit etiam ut verba vim suam super rationem retorqueant."* Into these logical discussions concerning the means of advancing the philosophy of human nature, Dr Reid has seldom entered; and still more rarely has he indulged him- self in tracing the numerous relations by which this philosophy is connected with the practical business of life. But he has done what was still more essential at the time he wrote : he has exemplified, with the happiest success, that method of investigation by which alone any solid progress can be made; directing his inquiries to a subject which formsanecessarygroundworkforthelabours of his successors— an analysis of the various powers and principles belonging to our con- stitution. Of the importance of this under- taking, it is sufficient to observe, that it . * This paeaage of Bacon forms the motto toaverv OF THOMAS It KID, D.D. K stands somewhat, although I confess not altogether, in the same relation to the dif- ferent branches of intellectual and moral science, (such as grammar, rhetoric, logic, ethics, natural theology, and politics,) in which the anatomy of the human body stands to the different branches of physio- logy and pathology. And, as a course of medical education naturally, or rather ne- cessarily, begins with a general survey of man's animal frame, so 1 apprehend that the proper, or rather the essential prepara- tion for those studies which regard our nobler concerns, is an examination of the firineiples which belong to man as an intel- igent, active, social, and moral being. Nor does the importance of such an analysis rest here ; it exerts an influence over all those sciences and arts which are connected with the material world ; and the philosophy of Bacon itself, while it points out the road to physical truth, is but a branch of the philo- sophy of the human mind. The substance of these remarks is admir- ably expressed by Mr Hume in the follow- ing passage— allowances being made for a few trifling peculiarities of expression, bor- rowed from the theories which were pre- valent at the time when he wrote : — " 'Tis evident that all the sciences have a relation, greater or less, to human nature ; and that, however wide any of them may seem to run from it, they still return back by one pass- age or another. Even mathematics, natural philosophy, and natural religion, are in some measure dependent on the science of man ; since they lie under the cognizance of men, and are judged of by their powers and facul- ties. It is impossible to tell what changes and improvements we might make in these sciences, were we thoroughly acquainted with the extent and force of human under- standing, and could explain the nature of the ideas we employ, and of the operations we perform in our reasonings. " If, therefore, the sciences of mathe- matics, natural philosophy, and natural religion, have such a dependence on the knowledge of man, what may be expected in the other sciences, whose connection with human nature is more close and intimate ? The sole end of logic is to explain the prin- ciples and operations of our reasoning faculty, and the nature of our ideas ; morals and criticism regard our tastes and senti- ments ; and politics consider men as united in society and dependent on each other. In these four sciences of logic, morals, criti- cism, and politics, is comprehended almost everything which it can any way import us to be acquainted with, or which can tend either to the improvement or ornament of the human mind. " Here, then, is the only expedient from which we can hope for success in our philo- sophical researches : to leave the tedious, lingering method, which we have hitherto followed ; and, instead of taking, now and then, a castle or village on the frontier, to march up directly to the capital or centre of these sciences — to human nature itself; which being once masters of, we may every- where else hope for an easy victory. From this station, we may extend our conquests over all those sciences which more intimately concern human life, and may afterwards proceed at leisure to discover more fully those which are the objects of pure curiosity. There is no question of importance whose decision is. not comprised in the science of man ; and there is none which can be de- cided with any certainty before we become acquainted with that science." To prepare the way for the accomplish- ment of the design so forcibly recommended in the foregoing quotation — by exemplifying, in an analysis of our most important intel- lectual and active principles, the only method of carrying it successfully into execution — was the great object of Dr Reid in all his various philosophical publications. In ex- amining these principles, he had chiefly in view a vindication of those fundamental laws of belief which form the groundwork of human knowledge, against the attacks made on their authority in some modern systems of scepticism ; leaving to his successors the more agreeable task of applying the philo- sophy of the mind to its practical uses. On the analysis and classification of our powers, which he has proposed, much room for im- provement must have been left in so vast an undertaking ; but imperfections of this kind do not necessarily affect the justness of his conclusions, even where they may suggest to future inquirers the advantages of a simpler arrangement, and a more de- finite phraseology. Nor must it be forgotten that, in consequence of the plan he has fol- lowed, the mistakes which may be detected in particular parts of his works imply no such weakness in the fabric he has reared as might have been justly apprehended, had he presented a connected system founded on gratuitous hypothesis, or on arbitrary definitions. The detections, on the con- trary, of his occasional errors, may be ex- pected, from the invariable consistency and harmony of truth, to throw new lights on those parts of his work where his inquiries have been more successful ; as the correc- tion of *.A particular mistatement in an authentic history is often found, by com- pleting an imperfect link, or reconciling a seeming contradiction, to dispel the doubts which hung over the most faithful and accurate details of the narrative. In Dr Reid's first performance, he con- fined himself entirely to the five senses, and the principles of our nature necessarily Iff ACCOUNT OF THE LIFE AND WRITINGS connected with tliom ; reserving the further prosecution of thesubjeet for afuture period. At that time, indeed, he seems to have thought, that a more comprehensive exami- nation of the mind was an enterprise too great for one individual. " The powers,"' he observes, " of memory, of imagination, of taste, of reasoning, of moral perception, the will, the passions, the affections, and all the active powers of the soul, present a boundless field of philosophical disquisition, which the author of this ' Inquiry' is far from thinking himself able to explore with accuracy. Many authors of ingenuity, ancient and modern, have made incursions into this vast territory, and have commu- nicated useful observations ; but there is reason to believe that those who have pre- tended to give us a map of the whole, have satisfied themselves with a very inaccurate and incomplete survey. If Galileo had attempted a complete system of natural philosophy, he had probably done little service to mankind ; but, by confining him- self to what was within his comprehension, he laid the foundation of a system of know- ledge, which rises by degrees, and does honour to the human understanding. New- ton, building upon this foundation, and in like manner, confining his inquiries to the law of gravitation, and the properties of light, performed wonders. If he had at- tempted a great deal more, he had done a great deal less, and perhaps nothing at all. Ambitious of following such great examples, with unequal steps, alas ! and unequal force, we have attempted an inquiry into one little corner only of the human mind ; that cor- ner which seems to be most exposed to vulgar observation, and to be most easily comprehended ; and yet, if we have deli- neated it justly, it must be acknowledged that the accounts heretofore given of it were very lame, and wide of the truth." From these observations, when compared with the magnitude of the work which the author lived to execute, there is some ground for supposing, that, in the progress of his researches, he became more and more sensible of the mutual connection and de- pendence which exists among the conclu- sions we form concerning the various prin- ciples of human nature ; even concerning those which seem, on a superficial view, to have the most remote relation to each other : and it was fortunate for the world, that, in this respect, he was induced to ex- tend his views so far beyond the limits of his original design. His examination, in- deed, of the powers of external perception, and of the questions immediately connected with them, bears marks of a still more minute diligence and accuracy than appear in some of his speculations concerning the ^ ther parts of our frame ; and what he has written on the former subject, in his In. quiry into the Human Mind," is evidently more highly finished, both in matter and form, than the volumes which he published in his more advanced years. The value, however, of these is inestimable to future adventurers in the same arduous under- taking ; not only in consequence of the aids they furnish as a rough draught of the field to be examined, but by the example they exhibit of a method of investigation on such subjects, hitherto very imperfectly under- stood by philosophers. It is by the origin- ality of this method, so systematically pur- sued in all his researches, still more than by the importance of his particular conclu- sions, that he stands so conspicuously dis- tinguished among those who have hitherto prosecuted analytically the study of man. I have heard it sometimes mentioned, as a subject of regret, that the writers who have applied themselves to this branch of knowledge have, in general, aimed at a great deal more than it was possible to ac- complish ; extending their researches to all the different parts of our constitution, while a long life might be well employed in examining and describing the phenomena connected with any one particular faculty. Dr Reid, in a passage already quoted from his " Inquiry," might have been supposed to give some countenance to this opinion, if his own subsequent labours did not so strongly sanction the practice in question. The truth, I apprehend, is, that such de- tached researches concerning the human mind can seldom be attempted with much hope of success ; and that those who have recommended them, have not attended suf- ficiently to the circumstances which so re- markably distinguish this study from that which has for its object the philosophy of the material world- A few remarks in illustration of this proposition seem to me to be necessary, in order to justify the rea- sonableness of Dr Reid's undertaking ; and they will be found to apply with still greater force to the labours of such as may wish to avail themselves of a similar analysis ifl^ explaining the varieties of human genius and character, or in developing the latent capacities of the youthful mind. One consideration of a more general nature is, in the first place, worthy of notice ; that, in the infancy of every science, the grand and fundamental desideratum is a bold and comprehensive outline ; some- what for the same reason that, in the cul- tivation of an extensive country, forests must be cleared and wildernesses reclaimed, before the limits of private property are fixed with accuracy ; and long before the period when the divisions and subdivisions,, of separate possessions give rise to the de# tails of a curious and refined husbandry. OF THOMAS REID, D.D. 17 The speculations of Lord Bacon embraced all the objects of human knowledge. Those of Newton and Boyle were confined to phy- sics ; but included an astonishing range of the material universe. The labours of their successors, in our own times, have been employed with no less zeal in pursuing those more particular, but equally abstruse investigations, in which they were unable to engage, for want of a sufficient stock both of facts and of general principles ; and which did not perhaps interest their curio- sity in any considerable degree. If these observations are allowed to hold to a certain extent with respect to all the sciences, they apply in a more peculiar manner to the subjects treated of .in Dr Keid's writings — subjects which are all so intimately connected, that it may be doubted if it be possible to investigate any one completely, without some general ac- quaintance, at least, with the rest. Even the theory of the understanding may re- ceive important lights from an examination of the active and the moral powers ; the state of which, in the mind of every indivi- dual, will be found to have a powerful in- fluence on his intellectual character ; — while, on the other hand, an accurate analy- sis of the faculties of the understanding, would probably go far to obviate the scep- tical difficulties which have been started concerning the origin of our moral ideas. It appears to me, therefore, that, whatever be the department of mental science that we propose more particularly to cultivate, it is necessary to begin with a survey of human nature in all its various parts ; studying these parts, however, not so much on their own account, as with a reference to the applications of which our conclusions are susceptible to our favourite purpose. The researches of Dr Reid, when consid- ered carefully in the relation which they bear to each other, afford numberless illustra- tions of the truth of this remark. His lead- ing design was evidently to overthrow the modern system of scepticism ; and, at every successive step of his progress, new and unexpected rights break in on his funda- mental principles. It is, however, chiefly in their practical application to the conduct of the under- standing, and the culture of the heart, that such partial views are likely to be danger- ous ; for here, they tend not only to mislead our theoretical conclusions, but to counter- act our improvement and happiness. Of this I am so fully convinced, that the most faulty theories of human nature, provided only they embrace the whole of it, appear to me less mischievous in their probable , effects than those more accurate and micro- scopical researches which are habitually I confined to one particular corner of our constitution. It is easy to conceive that, where the attention is wholly engrossed with the intellectual powers, the moral prin- ciples will be in danger of running to waste ; and it is no less certain, on the other hand, that, by confining our care to the moral constitution alone, we may suffer the under- standing to remain under the influence of unhappy prejudices, and destitute of those just and enlightened views without which the worthiest dispositions are of little use, either to ourselves or to society. An exclu- sive attention to any one of the subordinate parts of our frame — to the culture of taste, for example, or of the argumentative powers, or even to the refinement of our moral sen- timents and feelings — must be attended with a hazard proportionally greater. " In forming the human character," says Bacon, in a passage which Lord Bolingbroke has pronounced to be one of the finest and deepest in his writings, "we must not proceed as a statuary does in forming a statue, who works sometimes on the face, sometimes on the limbs, sometimes on the folds of the drapery ; but we must proceed (and it is in our power to proceed) as Nature does in forming a flower, or any other of her pro- ductions : she throws out altogether, and at once, the whole system of being, and the rudiments of all the parts. Rudimenta parLium omnium simul parit et producit"* Of this passage, so strongly marked with Bacon's capacious intellect, and so richly adorned with his "philosophical fancy," I will not weaken the impression by any comment ; and, indeed, to those who do not intuitively perceive its evidence, no comment would be useful. In what I have hitherto said of Dr Beid's speculations, I have confined myself to such general views of the scope of his researches, and of his mode of philosophizing, as seemed most likely to facilitate the perusal of his works to those readers who have not been much conversant with these abstract disqui- sitions. A slight review of some of the more important and fundamental objections which have been proposed to his doctrines, may, I hope, be useful as a farther preparation for the same course of study. Of these objections, the four following appear to me to be chiefly entitled to atten- tion : — 1. That he has assumed gratuitously, in all his reasonings, that theory concerning the human soul which the scheme of materialism calls in question. 2. That his views tend to damp the ardour of philosophical curiosity, by stat- ing as ultimate facts, phenomena which * In the foregoing paragraph. I have borrowed (with a very trifling alteration) Lord Bolingbroke's words, in a beautiful paraphrase on Bacon's remark —Sec his " Idea ot a Patriot Kiig." c IS ACCOUNT OF THE LIFE AND WRITINGS may be resolved into principles more simple and general. 3. That, by an unnecessary multiplica- tion of original or instinctive principles, he has brought the science of mind into a state more perplexed and unsatisfactory than that in which it was left by Locke and his successors. 4. That his philosophy, by sanctioning an appeal from the decisions of the learned to the voice of the multitude, is unfavour- able to a spirit of free inquiry, and lends additional stability to popular errors. 1. With respect to Dr Reid's supposed assumption of a doubtful hypothesis con- cerning the nature of the thinking and sentient principle, it is almost sufficient for me to observe, that the charge is directed against that very point of his philosophy in which it is most completely invulnerable. The circumstance which peculiarly charac- terises the inductive science of mind is, that it professes to abstain from all specu- lations concerning its nature and essence ; confining the attention entirely to pheno- mena for which we have the evidence of consciousness, and to the laws by which these phenomena are regulated. In this respect, it differs equally, in its scope, from the pneumatological discussions of the schools, and from the no less visionary theories so loudly vaunted by the physio- logical metaphysicians of more modern times. Compared with the first, it differs as the inquiries of the mechanical philoso- phers concerning the laws of moving bodies differ from the discussions of the ancient sophists concerning the existence and the nature of motion. Compared with the other, the difference is analogous to what exists between the conclusions of Newton concerning the law of gravitation, and his query concerning the invisible ether of which he supposes it might possibly be the effect. The facts which this inductive science aims at ascertaining, rest on their own proper evidence ; an evidence uncon- nected with all these hypotheses, and which would not, in the smallest degree, be affected, although the truth of any one of them should be fully established. It is not, therefore, on account of its inconsistency with any favourite opinions of my own, that I would oppose the disquisitions either of scholastic pneumatology, or of physiological metaphysics ; but because I consider them as an idle waste of time and genius on ques- tions where our conclusions can neither be verified nor overturned by an appeal to ex- periment or observation. Sir Isaac New- ton's query concerning the cause of gravi- tation was certainly not inconsistent with his own discoveries concerning its laws; but what would have been the consequences to the world, if he had indulged himself in the prosecutionofhypothetxal theories with respect to the former, instead of directing his astonishing powers to an investigation of the latter ? That the general spirit of Dr Reid's philosophy is hostile to the conclusions of the materialist, is indeed a fact. Not, however, because his system rests on the contrary hypothesis as a fundamental prin- ciple, but because his inquiries have a powerful tendency to wean the understand- ing gradually from those obstinate associa- tions and prejudices to which the common mechanical theories of mind owe aH their plausibility. It is, in truth, much more from such examples of sound research con- cerning the laws of thought, than from any direct metaphysical refutation, that a change is to be expected in the opinions of those who have been accustomed to con- found together two classes of phenomena, so completely and essentially different. But this view of the subject does not belong to the present argument, g /VDElOh ? It has been recommended of lafe, by a medical author of gr eat reputation, to those" 'who wish to study tne numan mind, to begin with preparing themselves for the task by the study of anatomy. I must con- fess, I cannot perceive the advantages of this order of investigation ; as the anatomy of the body does not seem to me more likely to throw light on the philosophy of the mind, than an analysis of the mind to throw light on the physiology of the body. To ascertain, indeed, the general laws of their connection from facts established by observ- ation or experiment, is a reasonable and most interesting object of philosophical curiosity ; and in this inquiry, (which was long ago proposed and recommended by Lord Bacon,) a knowledge of the constitu- tion both of mind and body is indispensably requisite ; but even here, if we wish to pro- ceed on firm ground, the two classes of facts must be kept completely distinct ; so that neither of them may be warped or distorted in consequence of theories suggested by their supposed relations or analogies.* Thus, in many of the phenomena connected with custom and habit, there is ample scope for investigating general laws, both with respect to our mental and our corporeal frame ; but what light do we derive from such information concerning this part of our constitution as is contained in the fol- lowing sentence of Locke ?_" Habits seem to be but trains of motion in the animal spirits, which, once set a-going, continue il wW-TT « epS they had been ™* *»' which, by often treading, are worn into » wSTlfSrJF**' " "» «— OF THOMAS REID, D.D. 19 smooth path." In like manner, the laws which regulate the connection between the mind and our external organs, in the case of perception, have furnished a very fertile subject of examination to some of the best of our modern philosophers ; but how im- potent does the genius of Newton itself appear, when it attempts to shoot the gulf which separates the sensible world and the sentient principle ! " Is not the sensorium of animals," he asks in one of his queries, " the place where the sentient substance is present, and to which the sensible species of things are brought through the nerves and brain, that they may be perceived by the mind present in that place ?" It ought to be remembered, also, that this inquiry, with respect to the laws regulating the connection between our bodily organiz- ation, and the phenomena subjected to our own consciousness, is but one particular department of the philosophy of the mind ; and that there still remains a wide, and, indeed, boundless region, where all our data must be obtained from our own mental operations. In examining, for instance, the powers of judgment and reasoning, let any person of sound understanding, after perus- ing the observations of Bacon on the differ- ent classes of our prejudices, or those of Locke on the abuse of words, turn his atten- tion to the speculations of some of our con- temporary theorists, and he will at once perceive the distinction between the two modes of investigation which I wish at pre- sent to contrast. " Reasoning," says one of the most ingenious and original of these, " is that operation of the sensorium by which we excite two or many tribes of ideas, and then re-excite the ideas in which they differ or correspond. If we determine this difference, it is called Judgment ; if we in vain endeavour to determine it, it is called Doubting ; if we re-excite the ideas in which they differ, it is called Distinguishing ; if we re-excite those in which they correspond, itis called Comparing."* In what accept- ation the word idea is to be understood in the foregoing passage, may be learned from the following definition of the same author : — " The word idea has various meanings in the writers of metaphysic : it is here used simply for those notions of external things which our organs of sense bring us ac- quainted with originally ; and is defined a contraction, or motion, or configuration, of the fibres which constitute the immediate organ of sense."+ Mr Hume, who was less of a physiologist than Dr Darwin, has made use of a language by no means so theoretical and arbitrary, but still widely removed from the simplicity and precision essentially neces- • » Zoonomia," vol. i. p 181 ,3d edit t Ibid., vol. i.pp..ll,12. sary in studies where everything depends on the cautious use of terms. "Belief,'' according to him, is " a lively idea related to or associated with a present impression ; Memory is the faculty by which we repeat our impressions, so as that they retain a considerable degree of their first vivacity, and are somewhat intermediate betwixt an idea and an impression." According to the views of Dr Reid, the terms which express the simple powers of the mind, are considered as unsusceptible of definition or explanation ; the words, Feeling, for example, Knowledge, Will, Doubt, Belief, being, in this respect, on the same footing with the words, Green or Scarlet, Sweet or Bitter. To the names of these mental operations, all men annex some notions, more or less distinct; and the only way of conveying to them notions more correct, is by teaching them to ex- ercise their own powers of reflection. The definitions quoted from Hume and Darwin, even if they were more unexceptionable in point of phraseology, would, for these rea- sons, be unphilosophical, as attempts to simplify what is incapable of analysis ; but, as they are actually stated, they not only envelope truth in mystery, but lay a found- ation, at the very outset, for an erroneous theory. It is worth while to add, that, of the two theories in question, that of Darwin, how inferior soever, in the estimation of competent judges, as a philosophical work, is by far the best calculated to impose on a very wide circle of readers, by the mix- ture it exhibits of crude and visionary me- taphysics, with those important facts and conclusions which might be expected from the talents and experience of such a writer, in the present advanced state of medical and physiological science. The questions which have been hitherto confined to a few, prepared for such discussions by habits of philosophical study, are thus submitted to the consideration, not only of the cultivated and enlightened minds which adorn the medical profession, but of the half -informed multitude who follow the medical trade : nor is it to be doubted, that many of these will give the author credit, upon subjects of whiph they feel themselves incompetent to judge, for the same ability which he dis- plays within their own professional sphere. The hypothetical principles assumed by Hume are intelligible to those only who are familiarized to the language of the schools ; and his ingenuity and elegance, captivating as they are to men of taste and refinement, possess slight attractions to the majority of such as are most likely to be misled by his conclusions. After all, I do not apprehend that the physiological theories concerning the mind, which have made so much noise of lats 5*0 ACCOUNT OF THE LIFE AND WRITINGS will produce a very lasting impression. The splendour of Dr Darwin's accomplish- ments could not fail to bestow a temporary importance on whatever opinions were sanc- tioned by his name ; as the chemical dis- coveries which have immortalized that of Priestley, have, for a while, recalled from oblivion the reveries of Hartley. But, ab- stracting from these accidental instances, in which human reason seems to have held aretrograde course, there has certainly been, since the time of Des Cartes, a continual, and, on the whole, a very remarkable ap- proach to the inductive plan of studying human nature. We may trace this in the writingB even of those who profess to con- sider thought merely as an agitation of the brain — in the writings more particularly of Hume and of Helvetius ; both of whom, although they may have occasionally ex- pressed themselves in an unguarded man- ner concerning the nature of mind, have, in their mrst useful and practical disquisi- tions, been prevented, by their own good sense, from blending any theory with re- spect to the causes of the intellectual phe- nomena with the history of facts, or the investigation of general laws. The authors who form the most conspicuous exceptions to this gradual progress, consist chiefly of men whose errors may be easily accounted for, by the prejudices connected with their circumscribed habits of observation and inquiry : of physiologists, accustomed to attend to that part alone of the human frame which the knife of the anatomist can lay open ; or of chemists, who enter on the analysis of thought, fresh from the decompositions of the laboratory — carrying into the theory of mind itself (what Bacon expressively calls) " the smoke and tarnish of the furnace." Of the value of such pur- suits, none can think more highly than myself ; but I must be allowed to observe, that the most distinguished pre-eminence in them does not necessarily imply a capa- city of collected and abstracted reflection, or an understanding superior to the preju- dices of early association, and the illusions of popular language. I will not go so far as Cicero, when he ascribes to those who possess these advantages, a more than ordinary vigour of intellect : — " Magni est ingenii revocare mentem a sensibus, et cogita- lionem a consueludine abducere." I would only claim for them the merit of patient and cautious research ; and would exact from their antagonists the same qualifica- tions.* In offering these remarks, I have no wish to exalt any one branch of useful knowledge at the expense of another, but to combat prejudices equally fatal to the * NoteD. progress of them all. With the same view, I cannot help taking notice of a prevailing, but very mistaken idea, that the formation of a hypothetical system is a stronger proof of inventive genius than the patient in- vestigation of Nature in the way of induc- tion. To form a system, appears to the young and inexperienced understanding, a species of creation ; to ascend slowly to general conclusions, from the observation and comparison of particular facts, is tc comment servilely on the works of another. No opinion, surely, can be more ground- less. To fix on a few principles, or even on a single principle, as the foundation of a theory ; and, by an artful statement of sup- posed facts, aided by a dexterous use oi language, to give a plausible explanation, by means of it, of an immense number of phenomena, is within the reach of most men whose talents have been a little exer- cised among the subtilties of the schools : whereas, to follow Nature through all her varieties with a quick yet an exact eye — to record faithfully what she exhibits, and to record nothing more — to trace, amidst the diversity of her operations, the simple and comprehensive laws by which they are regulated, and sometimes to guess at the beneficent purposes to which they are sub- servient — may be safely pronounced to be the highest effort of a created intelligence. And, accordingly, the number of ingenious theorists has, in every age, been great; that of sound philosophers has been won- derfully small ; — or, rather, they are only beginning now to have a glimpse of their way, in consequence of the combined lights furnished by their predecessors. Des Cartes aimed at a complete system of physics, deduced oprioHfromtheabstract suggestions of his own reason ; Newton as- pired no higher than at a faithful " inter- pretation of Nature," in a few of the more general laws which she presents to our no- tice : and yet the intellectual power displayed in the voluminous writings of the former vanishes into nothing when compared with what we may trace in a single page of the latter. On this occasion, a remark of Lord Bacon appears singularly apposite — that "Alexander and Caesar, thpugh they acted without the aid of magic or prodigy, per- formed exploits that are truly greater than what fable reports of King Arthur or Ama- dis de Gaul." I shall only add farther on this head, that the last observation holds more strictly with respect to the philosophy of the human mmd, than any other branch of science; for there is no subject whatever on which it is so easy to form theories calculated to impose on the multitude ; and none where the discovery of truth is attended with so many difficulties. One great cause of this OF THOMAS REID, D.D. 21 is, the analogical or theoretical terms em- ployed in ordinary language to express every thing relating either to our intellectual or active powers ; in consequence of which, specious explanations of the most mysteri- ous phenomena may be given to superficial inquirers ; while, at the same time, the la- bour of just investigation is increased to an incalculable degree. 2. To allege that, in this circumscription of the field of our inquiries concerning the mind, there is any tendency to repress a reasonable and philosophical curiosity, is a charge no less unfounded than the former ; inasmuch as every physical inquiry concern- ing the material world is circumscribed by limits precisely analogous. In all our in- vestigations, whatever their subject may be, the business of philosophy is confined to a reference of particular facts to other facts more general ; and our most successful re- searches must at length terminate in some law of nature, of which no explanation can be given. In its application to Dr Reid's writings, this objection has, I think, been more pointedly directed against his reason- ings concerning the process of nature in perception; a part of his writings which (as it is of fundamental importance in his general system) he has laboured with pecu- liar care. The result is, indeed, by no means flattering to the pride of those theorists who profess to explain everything; for it amounts to an acknowledgment that, after all the lights which anatomy and physiology supply, the information we obtain by means of our senses, concerning the existence and the qualities of matter, is no less incomprehen- sible to our faculties than it appears to the most illiterate peasant ; and that all we have gained, is a more precise and complete acquaintance with some particulars in our animal economy — highly interesting, indeed, when regarded in their proper light, as ac- cessions to our physical knowledge, but, considered in connection with the philoso- phy of the mind, affording only a more accurate statement of the astonishing phe- nomena which we would vainly endeavour to explain. This language has been charged, but most unjustly and ignorantly, with mys- ticism ; for the same charge may be brought, with equal fairness, against all the most im- portant discoveries in the sciences. It was, in truth, the very objection urged against Newton, when his adversaries contended, that gravity was to be ranked with the occult qualities of the schoolmen, till its mechanical cause should be assigned ; and the answer given to this objection, by Sir Isaac New- ton's commentator, Mr Maclaurin, may be literally applied, in the instance before us. to the inductive philosophy of the human mind :— " The opponents of Newton, finding no- thing to obj ect to his observations and reason- ings, pretended to find a resemblance between his doctrines and the exploded tenets of the scholastic philosophy. They triumphed mightily in treating gravity as an occult quality, because he did not pretend to de- duce this principle fully from its cause. . ... I know not that ever it was made an objection to the circulation of the blood, that there is no small difficulty in account- ing for it mechanically. They, too, who first extended gravity to air, vapour, and to all bodies round the earth, had their praise ; though the cause of gravity was as obscure as before ; or rather appeared more myste- terious, after they had shewn that there was no body found near the earth, exempt from gravity, that might be supposed to be its cause. Why, then, were his admirable discoveries, by which this principle was ex- tended over the universe, so ill relished by some philosophers ? The truth is, he had, with great evidence, overthrown the boasted schemes by which they pretended to unravel all the mysteries of nature ; and the philosophy he introduced in place of them, carrying with it a sincere confession of our being far from a complete and perfect knowledge of it, could not please those who had been accustomed to imagine themselves possessed of the eternal reasons and primary causes of all things. "It was, however, no new thing that this philosophy should meet with opposition. All the useful discoveries that were made in former times, and particularly in the seven- teenth century, had to struggle with the prejudices of those who had accustomed themselves, not so much. as to think but in a certain systematic way ; who could not be prevailed on to abandon their favourite schemes, while they were able to imagine the least pretext for continuing the dispute. Every art and talent was displayed to sup- port their falling cause ; no aid seemtd foreign to them that could in any manner annoy their adversary ; and such often was their obstinacy, that truth was able to make little progress, till they were succeeded by younger persons, who had not so strongly imbibed their prejudices." These excellent observations are not the less applicable to the subject now under consideration, that the part of Dr Reid's writings which suggested the quotation, leads only to the correction of an inveterate prejudice, not to any new general conclu- sion. It is probable, indeed, (now that the ideal theory has, in a great measure, dis- appeared from our late metaphysical sys- tems,) that those who have a pleasure in detracting from the merits of their prede- cessors, may be disposed to represent it as an idle waste of labour and ingenuity to have entered into a serious refutation of a hypo- '£4 ACCOUNT OF THE LIFE AND WHITINGS thesis at once gratuitous and inconceivable. A different judgment, however, will be formed by such as are acquainted with the extensive influence which, from the ear- liest accounts of science, this single preju- dice has had in vitiating almost every branch of the philosophy of the mind ; and who, at the same time, recollect the names of the illustrious men by whom, in more modern times, it has been adopted as an incontrovertible principle. It is sufficient for me to mention those of Berkeley, Hume, Locke, Clarke, and Newton. To the two first of these, it has served as the basis of their sceptical conclusions, which seem, in- deed, to follow from it as necessary conse- quences ; while the others repeatedly refer to it in their reasonings, as one of those facts' concerning the mind of which it would be equally superfluous to attempt a proof or a refutation. I have enlarged on this part of Dr Eeid's writings the more fully, as he was himself disposed, on all occasions, to rest upon it his chief merit as an author. In proof of this, I shall transcribe a few sen- tences from a letter of his to Dr Gregory, dated 20th August 1790 :— " It would be want of candour not to cwn that I think there is some merit in what you are pleased to call my Philoso- phy ; but I think it lies chiefly in having called in question the common theory of Ideas, or Images of things in the mind being the only objects of thought ; a theory founded on natural prejudices, and so uni- versally received as to be interwoven with the structure of language. Yet, were I to give you a detail of what led me to call in question this theory, after I had long held it as self-evident and unquestionable, you would think, as I do, that there was much of chance in the matter. The discovery was the birth of time, not of genius ; and Berkeley and Hume did more to bring it to light than the man that hit upon it. I think there is hardly anything that can be called mine in the philosophy of the mind, which does not follow with ease from the detection of this prejudice. " I must, therefore, beg of you most ear- nestly, to make no contrast in my favour to the disparagement of my predecessors in the same pursuit. I can truly say of them, and shall always avow, what you are pleased to say of me, that, but for the assistance I have received from their writ- ings, I never could have wrote or thought what I have done." 3. Somewhat connected with the last objection, are the censures which have been so frequently bestowed on Dr Beid, for an unnecessary and unsystematical multiplica- tion of original or instinctive principles. In reply to these censures, I have little to add to what I have remarked on the same topic, in the " Philosophy of the Human Mind." That the fault which is thus ascribed to Dr Eeid has been really committed by some ingenious writers in this part of the island, I most readily allow ; nor will I take upon me to assert that he has, in no instance, fallen into it himself. Such instances, however, will be found, on an accurate examination of his works, to be comparatively few, and to bear a very trifling proportion to those in which he has most successfully and decisively displayed his acuteness in exposing the premature and flimsy generalizations of his prede- cessors. A certain degree of leaning to that ex- treme to which Dr Reid seems to have inclined, was, at the time when he wrote, much safer than the opposite bias. From the earliest ages, the sciences in general, and more particularly the science of the human mind, have been vitiated by an undue love of simplicity ; and, in the course of the last century, this disposition, after having been long displayed in subtle theo- ries concerning the active powers, or the principles of human conduct, has been directed to similar refinements with respect to the faculties of the understanding, and the truths with which they are conversant. Mr Hume himself has coincided so far with the Hartleian school, as to represent the "principle of union and cohesion among our simple ideas as a kind of attraction, of as universal application in the mental world as in the natural ;"* and Dr Hartley, with a still more sanguine imagination, looked forward to an era " when future generations shall put all kinds of evidences and inquiries into mathematical forms; reducing Aristotle's ten categories, and Bishop Wilkin's forty summa genera, to the head of quantity alone, so as to make mathematics and logic, natural history and civil history, natural philosophy and philo- sophy of all other kinds, coincide, omni ex parte."f It is needless to remark the obvious ten- dency of such premature generalizations, to withdraw the attention from the study of particular phenomena ; while the effect of Reid's mode of philosophizing, even in those instances where it is carried to an ex- cess, is to detain us, in this preliminary step, a little longer than is absolutely ne- cessary. The truth is, that, when the phenomena are once ascertained, generaliz- ation is here of comparatively little value, and a task of far less difficulty than to observe facts with precision, and to record them with fairness. • <■ Treatise of Human Nature," vol. i. p so t i Hartley " On Man," p. 207, «o edit' London, OF THOMAS REID, D.D. 23 In no part of Dr Reid's writings, I am inclined to think, could more plausible criti- cisms be made on this ground, than in his classification of our active principles : but, even there, the facts are always placed fully and distinctly before the reader. That several of the benevolent affections which he has stated as ultimate facts in our con- stitution, might be analyzed into the same general principle differently modified, ac- cording to circumstances, there can, in my opinion, be little doubt. This, however, (as I have elsewhere observed,*) notwith- standing the stress which has been some- times laid upon it, is chiefly a question of arrangement. Whether we suppose these affections to be all ultimate facts, or some of them to be resolvable into other facts more general, they are equally to be regarded as constituent parts of human nature ; and, upon either supposition, we have equal reason to admire the wisdom with which that nature is adapted to the situation in which it is placed. The laws which regulate the acquired perceptions of sight, are surely as much a part of our frame as those which regulate any of our original perceptions ; and, although they require, for their developement, a certain degree of experience and observation in the individual, the uniformity of the result shews that there is nothing arbitrary nor accidental in their origin. In this point of view, what can be more philosophical, as well as beautiful, than the words of Mr Ferguson, that " natural affection springs up in the soul of the mother, as the milk springs in her breast, to furnish nourish- ment to her child!" "The effect is here to the race," as the same author has excel- lently observed, " what the vital motion of the heart is to the individual ; too neces- sary to the preservation of nature's works, to be intrusted to the precarious will or intention of those most nearly concerned."+ The question, indeed, concerning the origin of our different affections, leads to some curious analytical disquisitions; but is of very subordinate importance to those inquiries which relate to their laws, and uses, and mutual references. In many ethical systems, however, it seems to have been considered as the most interesting subject of disquisition which this wonder- ful part of our frame presents. In Dr Reid's " Essays on the Intellec- tual Powers of Man," and in his " Inquiry into the Human Mind," I recollect little • " Outlines of Moral Philosophy," pp. 19, 80, 2d edit. Edinburgh, 1801 . t '* Principles of Moral anil Political Science," part I. chap. I. sect 3. " Of the Principles of Society in Human Nature." The whole discussion unites, in a singular degree, the.soundest philosophy with the most eloquent description. that can justly incur a similar censure, notwithstanding the ridicule which Dr Priestley has attempted to throw on the last of these performances, in his " Table of Reid's Instinctive Principles."* To examine all the articles enumerated in that table, would require a greater latitude of disquisition than the limits of this memoir allow; and, therefore, I shall confine my observations to a few instances, where the precipitancy of the general criticism seems to me to admit of little dispute. In this light I cannot help considering it, when applied to those dispositions or determina- tions of the mind to which Dr Reid has given the names of the " Principle of Credulity," and the " Principle of Vera- city." How far these titles are happily chosen, is a question of little moment ; and on that point I am ready to make every concession. I contend only for what is essentially connected with the objection which has given rise to these remarks. "That any man," says Dr Priestley, " should imagine that a peculiar instinctive principle was necessary to explain our giving credit to the relations of others, appears to me, who have been used to see things in a different light, very extraordi- nary ; and yet this doctrine is advanced by Dr Reid, and adopted by Dr Beattie. But really," he adds, " what the former says in favour of it, is hardly deserving of the slightest notice. "•)- The passage quoted by Dr Priestley, in justification of this very peremptory deci- sion, is as follows : — " If credulity were the effect of reasoning and experience, it must grow up and gather strength in the same proportion as reason and experience do. But, if it is the gift of nature, it will be the strongest in childhood, and limited and restrained by experience ; and the most superficial view of human life shews that this last is the case, and not the first." To my own judgment, this argument of Dr Reid's, when connected with the ex- cellent illustrations which accompany it, carries complete conviction ; and I am con- firmed in my opinion by finding, that Mr Smith (a writer inferior to none in acute- ness, and strongly disposed, by the peculiar bent of his genius, to simplify, as far as possible, the philosophy of human nature) has, in the latest edition of his " Theory of Moral Sentiments," acquiesced in this very conclusion ; urging in support of it the same reasoning which Dr Priestley affects to estimate so lightly. " There seems to be in young children an instinctive * Examination of Reid's " Inquiry," &c. London 1774. f Examination of Reid's " Inquiry," &c, p. 88. 24 ACCOUNT OF THE LIFE AND WRITINGS disposition to believe whatever they are told. Nature seems to have judged it ne- cessary for their preservation that they should, for some time at least, put implicit confidence in those to whom the care of their childhood, and of the earliest and most necessary part of their education, is intrusted. Their credulity, accordingly, is excessive ; and it requires long and much experience of the falsehood of mankind to reduce them to a reasonable degree of diffi- dence and distrust."* That Mr Smith's opinion also coincided with Dr Eeid's, in what he has stated concerning the principle of veracity, appears evidently from the remarks which immediately follow the pas- sage just quoted. But I must not add to the length of this memoir by unnecessary citations. Another instinctive principle mentioned by Reid, is " our belief of the continuance of the present course of nature." " All our knowledge of nature," he observes, " be- yond our original perceptions, is got by experience, and consists in the interpreta- tion of natural signs. The appearance of the sign is followed \>y the belief of the thing signified. Upon this principle of our constitution, not only acquired perception, but also inductive reasoning, and all rea- soning from analogy, is grounded ; and, therefore, for want of a better name, we shall beg leave to call it the inductive prin- ciple. It is from the force of this principle that we immediately assent to that axiom upon which all our knowledge of nature is built, that effects of the same kind must have the same cause. Take away the light of this inductive principle, and ex- perience is as blind as a mole. She may indeed feel what is present, and what im- mediately touches her, but she sees nothing that is either before or behind, upon the right hand or upon the left, future or past." On this doctrine, likewise, the same critic has expressed himself with much severity ; calling it " a mere quibble ;" and adding, " every step that I take among this writer's sophisms, raises my astonish- ment higher than before." In this, how- ever, as in many other instances, he has been led to censure Dr Reid, not because he was able to see farther than his antago- nist, but because he did not see quite so far. Turgot, in an article inserted in the French " Encyclopeaie," and Condorcet, in a discourse prefixed to one of his mathe- matical publications,f have, both of them, stated the fact with a true philosophical precision; and, after doing so, have de- * Smith's "Theory," last edit, pari VII. sect 4. t " Rssai sur I'apphcation de l'analyse a la pro. ba.bilite des decisions rendues a la plurality des voix." Paris, 1785. duced from it an inference, not only flie same in substance with that of Dr Reid, but almost expressed in the same form of words. » In these references, as well as in that already made to Mr Smith's " Theory," I would not be understood to lay any undue stress on authority in a philosophical argu- ment. I wish only — by contrasting the modesty and caution resulting from habits of profound thought, with that theoretical intrepidity which a blindness to insuper- able difficulties has a tendency to inspire to^invite those whose prejudices against this part of Reid's system rest chiefly on the great names to which they conceive it to be hostile, to re-examine it with a little more attention, before they pronounce finally on its merits. The prejudices which are apt to occur against a mode of philosophizing so morti- fying to scholastic arrogance, are encour- aged greatly by that natural disposition, to refer particular facts to general laws, which is the foundation of all scientific arrange- ment ; a principle of the utmost importance to our intellectual constitution, but" which requires the guidance of a sound and ex- perienced understanding to accomplish the purposes for which it was destined. They are encouraged also, in no inconsiderable degree, by the acknowledged success of mathematicians, in raising, on the basis of a few simple data, the most magnificent, and, at the same time, the most solid fabric of science, of which human genius can boast. The absurd references which logicians are accustomed to make to Euclid's " Elements of Geometry," as a model which cannot be too studiously copied, both in physics and in morals, have contributed, in this as in a variety of other instances, to mislead phi- losophers from the study of facts, into the false refinements of hypothetical theory. On these misapplications of mathemati- cal method to sciences which rest ulti- mately on experiment and observation, I shall take another opportunity of offering some strictures. At present, it is suffi- cient to remark the peculiar nature of the truths about which pure or abstract mathe- matics are conversant. As these truths have all a necessary connection with each other, (all of them resting ultimately on those definitions or hypotheses which are the principles of our reasoning,) the beauty of the science cannot fail to increase ; in proportion to the simplicity of the data, compared with the incalculable variety of consequences which they involve : and to the simplifications and generalizations of theory on such a subject, it is perhaps im- possible to conceive any limit. How dif- ferent is the case in those inquiries where our first principles are not defimtiom but OF THOMAS RfilD, D.B. 25 facts , aud where our business is not to trace necessary connections, but the laws which regulate the established order of the universe ! In various attempts which have been lately made, more especially on the Conti- nent, towards a systematical exposition of the elements of physics, the effects of the mistake I am now censuring are extremely remarkable. The happy use of mathema- tical principles, exhibited in the writings of Newton and his followers, having ren- dered an extensive knowledge of them an indispensable preparation for the study of the mechanical philosophy, the early habits of thought acquired in the former pursuit are naturally transferred to the latter. Hence the illogical aud obscure manner in which its elementary principles have fre- quently been stated; an attempt being made to deduce, from the smallest possible number of data, the whole system of truths which it comprehends. The analogy exist- ing among some of the fundamental laws of mechanics, bestows, in the opinion of the multitude, an appearance of plausibility on such attempts ; and their obvious tendency is to withdraw the attention from that unity of design which it is the noblest employ- ment of philosophy to illustrate, by dis- guising it under the semblance of an eter- nal and necessary order, similar to what the mathematician delights to trace among the mutual relations of quantities and figures. These slight hints may serve as a reply in part to what Dr Priestley has suggested with respect to the consequences likely to 'follow, if the spirit of Reid's philosophy should be introduced into physics.* One consequence would unquestionably be, a careful separation between the principles •which we learn from experience alone, and those which are fairly resolvable, by ma- thematical or physical reasoning, into other facts still more general ; and, of course, a correction of that false logic which, while it throws an air of mystery over the plainest and most undeniable facts, levels the study of nature, in point of moral interest, with the investigations of the geometer or of the algebraist. It must not, however, be supposed, that, in the present state of natural philosophy, a false logic threatens the same dangerous effects as in the philosophy of the mind. It may retard somewhat the progress of the student at his first outset ; or it may con- found, in his apprehensions, the harmony of systematical order with the consistency and mutual dependency essential to a series of mathematical theorems : but the funda- mental truths of physics are now too well * " Examination of Reid's Inquiry, p 1 10. established, and the checks which it fur- nishes against sophistry are too numerous and palpable, to admit the possibility of any permanent error in our deductions. In the philosophy of the mind, so difficult is the acquisition of those habits of reflection which can alone lead to a correct knowledge of the intellectual phenomena, that a faulty hypothesis, if skilfully fortified by the im- posing, though illusory strength of arbitrary definitions and a systematical phraseology, may maintain its ground for a succession of ages. It will not, I trust, be inferred from anything I have here advanced, that I mean to offer an apology for those who, either in physics or morals, would pre- sumptuously state their own opinions with respect to the laws of nature, as a bar against future attempts to simplify and generalize them still farther. To assert that none of the mechanical explanations yet given of gravitation are satisfactory, and even to hint that ingenuity might be more profitably employed than in the search of such a theory, is something different from a gratuitous assumption of ultimate facts in physics ; nor does it imply an obstinate de- termination to resist legitimate evidence, should some fortunate inquirer — contrary to what seems probable at present— succeed where the genius of Newton has failed. If Dr Reid has gone farther than this in his conclusions concerning the principles which he calls original or instinctive, he has de- parted from that guarded language in which he commonly expresses himself — for all that it was of importance for him to conclude was, that the theories of his predecessors were, in these instances, exceptionable ; and the doubts he may occasionally insinu- ate, concerning the success of future adven- turers, so far from betraying any overween- ing confidence in his own understanding, are an indirect tribute to the talents of those from whose failure he draws an argument against the possibility of their undertaking. The same eagerness to simplify and to generalize, which led Priestley to complain of the number of Reid's instinctive prin- ciples, has carried some later philosophers a step farther. According to them, the very word instinct is unphilosophical ; and everything, either in man or brute, which has been hitherto referred to this mysteri- ous source, may be easily accounted for by experience or imitation. A few instances in which this doctrine appears to have been successfully verified, have been deemed sufficient to establish it without any limit- ation. \ InCa very original work) on which I have already hazarded some criticisms, much in- genuity has been employed in analyzing the wonderful efforts which the human infan' 26 ACCOUNT OF THE LIFE AND WRITINGS is enabled to make for its own preservation the moment after its introduction to the light. Thus, it is observed that the fcetus, while still in the uterus, learns to perforin the operation of swallowing ; arid also learns to relieve itself, by a change of posture, from the irksomeness of continued rest: and, therefore, (if we admit these proposi- tions,) we must conclude that some of the actions which infants are vulgarly supposed to perform in consequence of instincts coeval with birth, are only a continuation of actions to which they were determined at an earlier period of their being. The remark is inge- nious, and it may perhaps be just ; but it does not prove that instinct is an unphiloso- phical term ; nor does it render the opera- tions of the infant less mysterious than they seem to be on the common supposition. How far soever the analysis, in such in- stances, may be carried, we must at last arrive at some phcawmenon no less wonder- ful than that we mean to explain : in other words, we must still admit as an ultimate fact, the existence of an original determina- tion to a particular mode of action salutary or necessary to the animal ; and all we have accomplished is, to connect the origin of this instinct with an earlier period in the history of the human mind. The same author has attempted to ac- count, in a manner somewhat similar, for the different degrees in which the young of different animals are able, at the moment of birth, to exert their bodily powers. Thus, calves and chickens are able to walk almost immediately ; while the human in- fant, even in the most favourable situations, is six or even twelve months old before he can stand alone. For this Dr Darwin assigns two causes. 1. That the young of some animals come into the world in a more complete state than that of others — the colt and lamb, for example, enjoying, in this respect, a striking advantage over the puppy and the rabbit. 2. That the mode of walk- ing of some animals, coincides more per- fectly than that of others, with the previous motions of the ftstus in utero. The struggles of all animals, he observes, in the womb, must resemble their manner of swimming, as by this kind of motion they can best change their attitude in water. But the swimming of the calf and of the chicken resembles their ordinary movements on the ground, which they have thus learned in part to execute while concealed from our observation ; whereas, the swimming of the human infant differing totally from his manner of walking, he has no opportunity of acquiring the last of these arts till he is exposed to our view. The theory is ex- tremely plausible, and does honour to the author's sagacity ; but it only places in a new light that provident care which Nature | has taken of all her offspring in the infancy of their existence. Another instance may contribute towards a more ample illustration of the same sub- ject. A lamb, not many minutes after it is dropped, proceeds to search for its nour- ishment in that spot where alone it is to be found ; applying both its limbs and its eyes ts their respective offices. The peasant ob- serves the fact, and gives the name of in- stinct, or some corresponding term, to the unknown principle by which the animal is guided. On a more accurate examination of circumstances, the philosopher finds reason to conclude that it is by the sense of smelling it is thus directed to its object. In proof of this, among other curious facts, the following has been quoted : — " On dissecting," says Galen, "a goat great with young, I found a brisk emkrytm, and having detached it from the matrix, and snatching it away before it saw its dam, I brought it into a room where there were many vessels ; some filled with wine, others with oil, some with honey, others with milk, or some other liquor ; and in others there were grains and fruits. We first ob- served the young animal get upon its feet and walk ; then it shook itself, and after- wards scratched its side with one of its feet ; then we saw it smelling to every one of those things that were set in the room ; and, when it had smelt to them all, it drank up the milk."* Admitting this very beautiful story to be true, (and, for my own part, I am far from being disposed to ques- tion its probability,) it only enables us to state the fact with a little more precision, in consequence of our having ascertained, that it is to the sense of smelling the in- stinctive determination is attached. The conclusion of the peasant is not here at variance with that of the philosopher. It differs only in this, that he expresses him- self in those general terms which are suited to his ignorance of the particular process by which Nature, in this case, accomplishes her end ; and, if he did otherwise, he would be censurable for prejudging a ques- tion of which he is incompetent to form an accurate opinion. The application of these illustrations to some of Dr Reid's conclusions concerning the instinctive principles of the human mind, is, I flatter myself, sufficiently mani- fest. They relate, indeed, to a subject which differs, in various respects, from that which has fallen under his more particular- consideration ; but the same rules of philo- sophizing wili be found to apply equally to both. 4. The criticisms which have been made on what Dr Reid has written concerning • Darwin, m. i. ppi , Wj lgs OP THOMAS REID, D.D. 27 the intuitive truths which he distinguishes by the title of " Principles of Common Sense," would require a more ample dis- cussion than I can now bestow on them ; not that the importance of these criticisms (of such of them, at least, as I have happened to meet with) demands a long or elaborate refutation, but because the subject, accord- ing to the view I wish to take of it, involves some other questions of great moment and difficulty, relative to the foundations of human knowledge. Dr Priestley, the most formidable of Dr Reid's antagonists, has granted as much in favour of this doctrine as it is worth while to contend for on the present occasion. " Had these writers," he observes, with respect to Dr Reid and his followers, " assumed, as the elements of their Common Sense, certain truths which are so plain that no man could doubt of them, (without entering into the ground of our assent to them,) their conduct would ,have been liable to very little objection. AH jthat could have been said would have been, jthat, without any necessity, they had made an innovation in the received use of a term ; for no person ever denied that there are self-evident truths, and that these must be lassumed as the foundation of all our reason- ing. I never met with any person who did not acknowledge this, or heard of any argu- mentative treatise that did not go upon the supposition of it."* After such an acknow- ledgment, it is impossible to forbear asking, a with Dr Campbell,) " What is the great wint which Dr Priestley would controvert ? 'Is it, whether such self-evident truths shall "oe denominated Principles of Common Sense, Sr be distinguished by some other appella- tion ?"f ' That the doctrine in question has been, 1 n some publications, presented in a very Exceptionable form, I most readily allow ; k.ior would I be understood to subscribe to !l t implicitly, even as it appears in the works "if Dr Reid. It is but an act of justice to fiim, however, to request that his opinions iiay be judged of from his own works alone, Siot from those of others who may have j'happened to coincide with him in certain ikenets, or in certain modes of expression ; md that, before any ridicule be attempted An his conclusions concerning the authority *sf Common Sense, his antagonists would illake the trouble to examine in what accept- ation he has employed that phrase, i i The truths which Dr Reid seems, in most Ishstances, disposed to refer to the judgment rff this tribunal, might, in my opinion, be Renominated more unexceptionably, " fun- damental laws of human belief." They ml * « Examination of Dr Reid's Inquiry," Itc. p. *" t " Philosophv of Rhetoric," vol. i. p. ill — See — lote E, have been called by a very ingenious fo- reigner, (M. Trembley of Geneva,) but certainly with a singular infelicity of lan- guage, Prejuges Legitimes. Of this kind are the following propositions : — " I am the same person to-day that I was yesterday ;" " The material world has an existence in- dependent of that of percipient beings ;" " There are other intelligent beings in the universe beside myself;" " The future course of nature will resemble the past." Such truths no man but a philosopher ever thinks of stating to himself in words ; but all our conduct and all our reasonings pro- ceed on the supposition that they are admit- ted. The belief of them is essential for the preservation of our animal existence ; and it is accordingly coeval with the first opera- tions of the intellect. One of the first writers who introduced the phrase Common Sense into the tech- nical or appropriate language of logic, was Father Buffier, in a book entitled, " Traite des Premieres Verites." It has since been adopted by several authors of note in this country ; particularly by Dr Reid, Dr Os- wald, and Dr Beattie; by all of whom, however, I am afraid, it must be confessed, it has been occasionally employed without a due attention to precision. The last of these writers uses it* to denote that power by which the mind perceives the truth of any intuitive proposition ; whether it be an axiom of abstract science ; or a statement of some fact resting on the immediate inform- ation of consciousness, of perception, or of memory ; or one of those fundamental laws of belief which are implied in the ap- plication of our faculties to the ordinary business of life. The same extensive use of the word may, I believe, be found in the other authors just mentioned. vBut no authority can justify such a laxity in the employment of language in philosophical discussions^for, if mathematical axioms be (as they are, manifestly and indisputably) a class of propositions essentially distinct from the other kinds of intuitive truths now described, why refer them all indis- criminately to the same principle in our constitution ? If this phrase, therefore, be at all retained, precision requires that it should be employed in a more limited ac- ceptation ; and, accordingly, in the works under our consideration, it is appropriated most frequently, though by no means uni- formly, to that class of intuitive truths which I have already called " fundamental laws of belief."f When thus restricted, it conveys a notion, unambiguous, at least, • "Essay on Truth," edition second, p. 40, el seq. ; also p. 166, et seq. + This seems to be nearly the meaning annexed to the phrase, by the learned and acute author of " The Philosophy of Rhetoric," vol. i p 109, et seq. 21! ACCOUNT OF THE LIFE AND WRITINGS and definite ; and, consequently, the ques- tion about its propriety or impropriety turns entirely on the coincidence of this definition with the meaning of the word as employed in ordinary discourse. What- ever objections, therefore, may be stated to the expression as now defined, will apply to it with additional force, when used with the latitude which has been already censured. I have said that the question about the propriety of the phrase Common Sense as employed by philosophers, must be decided by an appeal to general practice ; for, although it be allowable, and even neces- sary, for a philosopher to limit the accepta- tion of words which are employed vaguely in common discourse, it is always dangerous to give to a. word a scientific meaning essentially distinct from that in which it is usually understood. It has, at least, the effect of misleading those who do not enter deeply into the subject ; and of giving a paradoxical appearance to doctrines which, if expressed in more unexceptionable terms, would be readily admitted. It appears to me that this has actually happened in the present instance. The phrase Common Sense, as it is generally understood, is nearly synonymous with mother-wit; denoting that degree of sagacity (depending partly on original capacity, and partly on personal experience and observa- tion) which qualifies an individual for those simple and essential occupations which all men are called on to exercise habitually by their common nature. In this acceptation, it is opposed to those mental acquirements which are derived from a regular education, and from the study of books ; and refers, not to the speculative convictions of the under- standing, but to that prudence and discretion which are the foundation of successful con- duct. Such is the idea which Pope annexes to the word, when, speaking of good sense, (which means only a more than ordinary share of common sense,) he calls it " The gift of Heaven, And, though no science, fairly worth the seven." To speak, accordingly, of appealing from the conclusions of philosophy to common sense, had the appearance, to title-page readers, of appealing from the verdict of the learned to the voice of the multitude ; or of attempting to silence free discussion by a reference to some arbitrary and undefinable standard, distinct from any of the intel- lectual powers hitherto enumerated by logi- cians. Whatever countenance may be sup- posed to have been given by some writers to such an interpretation of this doctrine, I may venture to assert that none is afforded by the works of Dr Reid. The standard to which he appeals is neither the creed of a particular sect, nor the inward light of 1 enthusiastic presumption, but that constitu- tion of human nature without which all the business of the world would immediately cease ; and the substance of his argument amounts merely to this, that those essential laws of belief to which sceptics have objected, when considered in connection with our scientific reasonings, are implied in every step we take as active beings ; and if called in question by any man in his prac- tical concerns would expose him universally to the charge of insanity. In stating this important doctrine, it were perhaps to be wished that the subject had been treated with somewhat more of ana- lytical accuracy ; and it is certainly to be regretted that a phrase should have been employed, so well calculated by its ambiguity to furnish a convenient handle to misre- presentations; but, in the judgment of those who have perused Dr Eeid's writings with an intelligent and candid attention, these misrepresentations must recoil on their authors ; while they who are really inter- ested in the progress of useful science, will be disposed rather to lend their aid in sup- plying what is defective in his views than to reject hastily a doctrine which aims, by the developement of some logical principles overlooked in the absurd systems which have been borrowed from the schools, to vin- dicate the authority of truths intimately and extensively connected withhuman happiness. In the prosecution of my own speculations on the human mind, I shall have occasion to explain myself fully concerning this, as well as various other questions connected - with the foundations of philosophical evi- dence. The new doctrines and newphrase- ology on that subject, which have lately become fashionable among some metaphy- sicians in Germany, and which, in my opinion, have contributed not a little to involve it in additional obscurity, are a sufficient proof that this essential and funda- mental article of logic is not as yet com- , pletely exhausted. In order to bring the foregoing remarks within some compass, I have found it necessary to confine myself to such objec- tions as strike at the root of Dr Reid's philosophy, without touching on any of his , opinions on particular topics, however im- portant. I have been obliged also to com- press what I have stated within narrower limits than were perhaps consistent with j complete perspicuity ; and to reject many illustrations which crowded upon me at almost every step of my progress. It may not, perhaps, be superfluous to add, that, supposing some of these objections to possess more force than I have ascribed to them in my reply, it will not therefore follow, that little advantage is to be derived OF THOMAS REID, D.D. 29 from a careful perusal of the speculations against which they are directed. Even they who dissent the most widely from Dr Reid's conclusions, can scarcely fail to admit, that, as a writer, he exhibits a striking contrast to the most successful of his predecessors, in u, logical precision and simplicity of language — his statement of facts being neither vitiated by physiological hypothesis, nor obscured by scholastic mystery. Who- ever has reflected on the infinite importance, in such inquiries, of a skilful use of words as the essential instrument of thought, must be aware of the influence which his works are likely to have on the future pro- gress of science, were they to produce no other effect than a general imitation of his mode of reasoning, and of his guarded It is not, indeed, every reader to whom these inquiries are accessible ; for habits of attention in general, and still more habits of attention to the phmnomena of thought, require early and careful cultivation ; but those who are capable of the exertion will soon recognise, in Dr Reid's statements, the faithful history of their own minds, and will find their labours amply rewarded by that satisfaction which always accompanies the discovery of useful truth. They may expect, also, to be rewarded by some intel- lectual acquisitions not altogether useless in their other studies. An author well quali- fied to judge, from his own experience, of whatever conduces to invigorate or to em- bellish the understanding, has beautifully remarked, that " by turning the soul inward on itself, its forces are concentrated, and are fitted for stronger and bolder flights of science ; and that, in such pursuits, whether we take, or whether we lose the game, the chase is certainly of service."* In this respect, the philosophy of the mind (ab- stracting entirely from that pre-eminence which belongs to it in consequence of its practical applications) may claim a distin- guished rank among those preparatory dis- ciplines which another writer, of no less eminence, has happily compared to " the crops which are raised, not for the sake of the harvest, but to be ploughed in as a dress- ing to the land."-)- SECTION III. CONCLUSION OF THE NARRATIVE. The three works to which the foregoing remarks refer — together with the Essay on Quantity, published in the " Philosophical * Preface to Mr Burke's " Essay on the Sublime and Beautiful." t Bishop Berkeley's " Querist." Transactions of the Royal Society of Lon- don," and a short but masterly Analysis of Aristotle's Logic, which forms an ap- pendix to the third volume of Lord Karnes' " Sketches" — comprehend the whole of Dr Reid's publications. * The interval between the dates of the first and last of these amounts to no lees than forty years, although he had attained to the age of thirty-eight before he ventured to appear as an author. With the " Essays on the Active Powers of Man," he closed his literary career ; but he continued,, notwithstanding, to prosecute his studies with unabated ardour and activity. The more modern improvements in chemis- try attracted his particular notice ; and he applied himself, with his wonted diligence and success, to the study of its new doctrines and new nomenclature. He amused him- self also, at times, in preparing, for a philo- sophical society of which he was a member, short essays on particular topics which happened to interest his curiosity, and on which he thought he might derive useful hints from friendly discussion. The most important of these were — " An Examination of Priestley's Opinions concerning Matter and Mind ;" " Observations on the ' Utopia' of Sir Thomas More ;" and " Physiologi- cal Reflections on Muscular Motion." This last essay appears to have been written in the eighty-sixth year of his age, and was read by the author to his associates, a few months before his death. His " thoughts were led to the speculations it contains," (as he himself mentions in the conclusion,) " by the experience of some of the effects which old age produces on the muscular motions." '* As they were occasioned, therefore," he adds, " by the infirmities of age, they will, I hope, be heard with the greater indulgence." Among the various occupations with which he thus enlivened his retirement, the mathematical pursuits of his earlier years held a distinguished place. He delighted to converse about them with his friends ; and often exercised his skill in the investi- gation of particular problems. His know- ledge of ancient geometry had not probably been, at any time, very extensive ; but he had cultivated diligently those parts of mathematical science which are subservient to the study of Sir Isaac Newton's works. He had a predilection, more particularly, for researches requiring the aid of arith- metical calculation, in the practice of which he possessed uncommon expertness and address. I think I have sometimes ob- served in him a slight and amiable vanity, connected with this accomplishment. * Reid's " History of the University of Glasgow" was published, after his death, in the " Sratistical Account of Scotland." It is how, for the first time, added to his other works.— H. 30 ACCOUNT OF THE LIFE AND WRITINGS The revival, at this period, of Dr Reid's first scientific propensity, has often recalled to me a favourite remark of Mr Smith's that of all the amusements of old age, the most grateful and soothing is a renewal of acquaintance with the favourite studies and favourite authors of our youth ; a re- mark which, in his own case, seemed to be more particularly exemplified, while he was re-perusing, with the enthusiasm of a stu- dent, the tragic poets of ancient Greece. I heard him, at least, repeat the observa- tion more than once, while Sophocles or Euripides lay open on his table. In the case of Dr Reid, other motives perhaps conspired with the influence of the agreeable associations to which Mr Smith probably alluded. His attention was always fixed on the state of his intellectual facul- ties ; and for counteracting the effects of time on these, mathematical studies seem to be fitted in a peculiar degree. They are fortunately, too, within the reach of many individuals, after a decay of memory dis- qualifies them for inquiries which involve a multiplicity of details. Such detached problems, more especially, as Dr Reid com- monly selected for his consideration — pro- blems where all the data are brought at once under the eye, and where a connected train of thinking is not to be carried on from day to day — will be found, (as I have wit- nessed with pleasure in several instances,) by those who are capable of such a recrea- tion, a valuable addition to the scanty re- sources of a life protracted beyond the or- dinary limit. While he was thus enjoying an old age happy in some respects beyond the usual lot of humanity, his domestic comfort suf- fered a deep and incurable wound by the death of Mrs Reid. He had had the mis- fortune, too, of surviving, for many years, a numerous family of promising children ; four of whom (two sons and two daughters) died after they attained to maturity. One daughter only was left to him when he lost his wife ; and of her affectionate good offices he could not always avail himself, in con- sequence of the attentions which her own husband's infirmities required. Of this lady, who is still alive, (the widow of Patrick Carmichael, M. D.,*) I shall have occasion again to introduce the name, be- fore I conclude this narrative. * A learned and worthy physician, who, after a long residence in Holland, where he practised medi- cine, retired to Glasgow. He was a younger 6on of Professor Gerschom Carmichael, who published, about the year 1720, an edition of Puffendorff, De Officio Hominis et Civis, and who is pronounced by Dr Hutcheson, " by far the best commentator on that book." [Carmichael was Hutcheson's imme- diate predecessor in the chair of Moral Philosophy in the University of Glasgow, and may be regarded, on good grounds, as the real founder of the Scottish school of philosophy. — H.] A short extract from a letter addressed to myself by Dr Reid, not many weeks after his wife's death, will, I am persuaded, be acceptable to many, as an interesting relic of the writer. " By the loss of my bosom friend, with whom I lived fifty-two years, I am brought into a kind of new world, at a time of life when old habits are not easily forgot, or new ones acquired. But every world is God's world, and I am thankful for the comforts he has left me. Mrs Carmichael has now the care of two old deaf men, and does every thing in her power to please them; and both are very sensible of her goodness. I have more health than, at my time of life, I had any reason to expect. I walk about; entertain myself with reading what I soon forget ; can converse with one person, if he articulates distinctly, and is within ten inches of my left ear ; go to church, without hearing one word of what is said. You know I never had any pretensions to viva- city, but I am still free from languor and ennui. " If you are weary of this detail, impute it to the anxiety you express to know the state of my health. I wish you may have no more uneasiness at my age, — being yours most affectionately." About four years after this event, ha was prevailed on, by his friend and relation, Dr Gregory, to pass a few weeks, during the summer of 1796, at Edinburgh. He was accompanied by Mrs Carmichael, who lived with him in Dr Gregory's house ; a situation which united under the same roof, every advantage of medical care, of tender attachment, and of philosophical inter- course. As Dr Gregory's professional en- gagements, however, necessarily interfered much with his attentions to his guest, I enjoyed more of Dr Reid's society than might otherwise have fallen to my share. I had the pleasure, accordingly, of spend- ing some hours with him daily, and of attending him in his walking excursions, which frequently extended to the distance of three or four miles. His faculties (ex- cepting his memory, which was considerably impaired) appeared as vigorous as ever; and, although his deafness prevented him from taking any share in general conversa- tion, he was still able to enjoy the company of a friend. Mr Playfair and myself were both witnesses of the acuteness which he displayed on one occasion, in detecting a mistake, by no means obvious, in a manu- script of his kinsman, David Gregory, on the subject of " Prime and Ultimate Ratios." Nor had his temper suffered from the hand of time, either in point of gentleness or of gaiety. " Instead of repining at the en- joyments of the young, he delighted in pro- moting them ; and, after all the losses he OF THOMAS REID, D.D. 31 had Sustained in his own family, he con- tinued to treat children with such conde- scension and benignity, that some very young ones noticed the peculiar kindness of his eye."» In apparent soundness and activity of body, he resembled more a man of sixty than of eighty-seven. He returned to Glasgow in his usual health and spirits ; and continued, for some weeks, to devote, as formerly, a regular por- tion of his time to the exercise both of body and of mind. It appears, from a letter of Dr Cleghorn's to Dr Gregory, that he was still able to work with his own hands in his garden ; and he was found by Dr Brown, occupied in the solution of an algebraical problem of considerable difficulty, in which, after the labour of a day or two, he at last succeeded. It was in the course of the same short interval, that he committed to writing those particulars concerning his an- cestors, which I have already mentioned. This active and useful life was now, how- ever, drawing to a conclusion. A violent disorder attacked him about the end of September ; but does not seem to have occasioned much alarm to those about him, till he was visited by Dr Cleghorn, who soon after communicated his apprehensions in a letter to Dr Gregory. Among other symptoms, he mentioned particularly "that alteration of voice and features which, though not easily described, is so well known to all who have opportunities of seeing life close." Dr Reid's own opinion of his ease was probably the same with that of his physician ; as he expressed to him on his first visit his hope that he was "soon to get his dismission." After a severe struggle, attended with repeated strokes of palsy, he died on the 7th of October following. Dr Gregory had the melancholy satisfaction of visiting his venerable friend on his death- bed, and of paying him this Unavailing mark of attachment before his powers of recol- lection were entirely gone. The only surviving descendant of Dr Reid is Mrs Carmichael, a daughter worthy in every respect of such a father — long the chief comfort and support of his old age, and his anxious nurse in his last moments, t In point of bodily constitution, few men have been more indebted to nature than Dr Reid. His form was vigorous and athletic ; and his muscular force (though he was somewhat under the middle size) uncom- monly great ; advantages to which his habits of temperance and exercise, and the un- clouded serenity of his temper, did ample * I have borrowed this sentence from a just and elegant-character of Dr .Reid, which appeared, a few days after his death, in one of the Glasgow journals. I had occasion frequently to verify the truth of the observation during his visit to Edinburgh. t Note F justice. His countenance was strongly expressive of deep and collected thought ; but, when brightened up by the face of a friend, what chiefly caught the attention was a look of good- will and of kindness. A picture of him, for which he consented, at the particular request of Dr Gregory, to sit to Mr Raeburn, during his last visit to Edinburgh, is generally and justly ranked among the happiest performances of that excellent artist. The medallion of Tassie, also, for which he sat in the eighty-first year of his age, presents a very perfect resemblance. I have little to add to what the foregoing pages contain with respect to his character. Its most prominent features were, intrepid and inflexible rectitude, a pure and devoted attachment to truth, and an entire com- mand (acquired by the unwearied exertions of a long fife) over all his passions. Hence, in those parts of his writings where his subjectforces him to dispute the conclusions of others, a, scrupulous rejection of every expression calculated to irritate those whom he was anxious to convince ; and a spirit of liberality and good-humour towards his opponents, from which no asperity on then- part could provoke him for a moment to deviate. The progress of useful knowledge, more especially in what relates to human nature and to human life, he believed to be retarded rather than advanced by the in- temperance of controversy ; and to be secured most effectually when intrusted to the slow but irresistible influence of sober reasoning. That the argumentative talents of the disputants might be improved by such altercations, he was willing to allow ; but, considered in their connection with the great objects which all classes of writers profess equally to have in view, he was convinced " that they have done more harm to the practice, than they have done service to the theory, of morality.'* In private life, no man ever maintained, more eminently or more uniformly, the dignity of philosophy ; combining with the most amiable modesty and gentleness, the noblest spirit of independence. The only preferments which he ever enjoyed he owed to the unsolicited favour of the two learned bodies who successively adopted him into their number ; and the respectable rank which he supported in society was the well- earned reward of his own academical la- bours. The studies in which he delighted were little calculated to draw on him the patronage of the great ; and he was un- skilled in the art of courting advancement by " fashioning his doctrines to the varying hour." As a philosopher, his genius was more * Preface to Pope's " Essay on Man." 32 ACCOUNT OF THE LIFE AND WRITINGS peculiarly characterised by a sound, cautious, distinguishing judgment, by a singular patience and perseverance of thought, and by habits of the most fixed and concentrated attention to his own mental operations ; endowments which, although not the most splendid in the estimation of the multitude, would seem entitled, from the history of science, to rank among the rarest gifts of the mind. With these habits and powers, he united (what does not always accompany them) the curiosity of a naturalist, and the eye of an observer ; and, accordingly, his inform- ation about everything relating to physical science, and to the useful arts, was exten- sive and accurate. His memory for his- torical details was not so remarkable ; and he used sometimes to regret the imperfect degree in which he possessed this faculty. I am inclined, however, to think, that, in doing so, he underrated his natural advan- tages ; estimating the strength of memory, as men commonly do, rather by the recol- lection of particular facts, than by the pos- session of those general conclusions, from a subserviency to which such facts derive their principal value. Towards the close of life, indeed, his memory was much less vigorous than the other powers of his intellect ; in none of which could I ever perceive any symptom of decline. His ardour for knowledge, too, remained unextinguished to the last ; and, when cherished by the society of the young and inquisitive, seemed even to increase with his years. What is still more remark- able, he retained, in extreme old age, all the sympathetic tenderness and all the moral sensibility of youth ; the liveliness of his emotions, wherever the happiness of others was concerned, forming an affecting con- trast to his own unconquerable firmness under the severest trials. Nor was the sensibility which he retained the selfish and sterile offspring of taste and indolence. It was alive and active, wher- ever he could command the means of re- lieving the distresses or of adding to the comforts of others ; and was often felt in its effects, where he was unseen and unknown. Among the various proofs of this which have happened to fall under my own know- ledge, I cannot help mentioning particularly (upon the most unquestionable authority) the secrecy with which he conveyed his occasional benefactions to his former parish- ioners at New-Machar, long after his esta- blishment at Glasgow. One donation, in particular, during the scarcity of 1782 — a donation which, notwithstanding all his precautions, was distinctly traced to his beneficence — might perhaps have been thought disproportionate to his limited in- come, had not his own simple and moderate habits multiplied the resources of hit humanity. His opinions on the most important sub- jects are to be found in his works ; and that spirit of piety which animated every part of his conduct forms the best comment on their practical tendency. In the state in which he found the philosophical world, he believed that his talents could not be so usefully employed as in combating the schemes of those who aimed at the com- plete subversion of religion, both natural and revealed ; convinced, with Dr Clarke, that, " as Christianity presupposes the truth of Natural Religion, whatever tends to discredit the latter must have a propor- tionally greater effect in weakening the authority of the former."* In his views of both, he seems to have coincided nearly with Bishop Butler, an author whom Tie held in the highest estimation. A very careful abstract of the treatise entitled " Analogy," drawn up by Dr Reid, many years ago, for his own use, still exists among his manuscripts ; and the short " Dissertation on Virtue" which Butler has annexed to that work, together with the " Discourses on Human Nature" published in his volume of Sermons, he used always to recommend as the most satisfactory ac- count that has yet appeared of the funda- mental principles of Morals : nor could he conceal his regret, that the profound philo- sophy which these Discourses contain should of late have been so generally sup- planted in England by the speculations of some other moralists, who, while they pro- fess to idolize the memory of Locke, " approve little or nothing in his writings, but his errors. "+ Deeply impressed, however, as he was with Ins own principles, he possessed the most perfect liberality towards all whom he believed to be honestly and conscientiously devoted to the search of truth. With one very distinguished character, the late Lord Karnes, he lived in the most cordial and affectionate friendship, notwithstanding the avowed opposition of their sentiments on some moral questions to which he attached the greatest importance. Both of them, however, were the friends of virtue and of mankind ; and both were able to temper the warmth of free discussion with the for- bearance and good humour founded on re- ciprocal esteem. No two men, certainly, ever exhibited a more striking contrast in their conversation, or in their constitutional tempers : — the one, slow and cautious in * Collection of Papers which passed between Leib. nitt and Clarke. See Dr Clarke's Dedication. t I have adopted here, the words which Dr Clarkl applied to some of Mr Locke's earlier followers. They are still more applicable to many-writers of thf present times See Clarke's First Reply to Leib. nit*. v OF THOMAS REID, D.D. 33 his decisions, even on those topics which he had most diligently studied ; reserved and silent in promiscuous society ; and re- taining, after all his literary eminence, the same simple and unassuming manners which he brought from his country residence : the other, lively, rapid, and communicative ; accustomed, by his professional pursuits, to wield with address the weapons of con- troversy, and not averse to a trial of his powers on questions the most foreign to his ordinary habits of inquiry. But these cha- racteristical differences, while to their com- mon friends they lent an additional charm to the distinguishing merits of each, served only to enliven their social intercourse, and to cement their mutual attachment. I recollect few, if any anecdotes of Dr Reid, which appear to me calculated to throw additional light on his character ; and I suspect strongly, that many of those which are to be met with in biographical publications are more likely to mislead than to inform. A trifling incident, it is true, may sometimes paint a peculiar fea- ture better than the most elaborate descrip- tion ; but a selection of incidents really characteristical, presupposes, in the ob- server, a rare capacity to discriminate and to generalize ; and where this capacity is wanting, a biographer, with the most scru- ^ pulous attention to the veracity of his de- tails, may yet convey a very false concep- tion of the individual he would describe. As, in the present instance, my subject afforded no materials for such a choice, I have attempted, to the best of my abilities, (instead of retailing detached fragments of conversations, or recording insulated and unmeaning occurrences,) to communicate to others the general impressions which Dr Reid's character has left on my own mind. In this attempt I am far from being confi- dent that I have succeeded ; but, how barren soever I may have thus rendered my pages in the estimation of those who consider biography merely in the light of an amusing tale, I have, at least, the satisfaction to think, that my picture, though faint in the colouring, does not present a distorted re- semblance of the original. The confidential correspondence of an individual with his friends, affords to the student of human nature, materials of far greater authenticity and importance; more particularly, the correspondence of a man like Dr Reid, who will not be suspected by those who knew him, of accommodating his letters (as has been alleged of Cicero) to the humo rs and principles of those whom he addressed. I am far, at the same time, from thinking that the correspondence of Dr Reid would be generally interesting; or even that he excelled in this species of writing : but few men, I sincerely believe, who have written so much, have left be- hind them such unblemished memorials of their virtue. At present, I shall only transcribe two letters, which I select from a considerable number now lying before me, as they seem to accord, more than the others, with the general design of this Memoir. The first (which is dated January 13, 1779) is ad- dressed to the Rev. William Gregory, (now Rector of St Andrew's, Canterbury,) then an undergraduate in Balliol College, Oxford. It relates to a remarkable pecu- liarity in, Dr Reid's physical temperament,- connected with the subject of dreaming ; and is farther interesting as a genuine re- cord of some particulars in his early habits, in which it is easy to perceive the openings of a superior mind. " The fact which your brother the Doctor desires to be informed of, was as you men- tion it. As far as I remember the circum- stances, they were as follow : — " About the age of fourteen, I was, almost every night, unhappy in my sleep, from frightful dreams : sometimes hanging over a dreadful precipice, and just ready to drop down ; sometimes pursued for my life, and stopped by a wall, or by a sudden loss of all strength ; sometimes ready to be de- voured by a wild beast. How long I was plagued with such dreams, I do not now recollect. I believe it was for a year or two at least ; and I think they had quite left me before I was fifteen. 1 n those days, I was much given to what Mr Addison, in one of his " Spectators," calls castle-build- ing ; and, in my evening solitary walk, which was generally all the exercise I took, my thoughts would hurry me into some active scene, where I generally acquitted myself much to my own satisfaction ; and in these scenes of imagination I performed many a gallant exploit. At the same time, in my dreams I found myself the most arrant coward that ever was. Not only my cour- age, but my strength failed me in every danger ; and I often rose from my bed in the morning in such a panic that it took some time to get the better of it. I wished very much to get free of these uneasy dreams, which not only made me unhappy in sleep, but often left a disagreeable im- pression in my mind for some part of the following day. I thought it was worth trying whether it was possible to recollect that it was all a dream, and that I was in no real danger. I often went to sleep with my mind as strongly impressed as I could with this thought, that I never in my life- time was in any real danger, and that every fright I had was a dream. After many fruitless endeavours to recollect this when the danger appeared I effected it at last, and have often, when I was sliding over a 34 ACCOUNT OF THE LIFE AND WRITINGS precipice into the abyss, recollected that it was all a dream, and boldly jumped down. The effect of this commonly was, that I immediately awoke. But I awoke calm and intrepid, which I thought a great ac- quisition. After this, my dreams were never very uneasy ; and, in a short time, I dreamed not at all. " During all this time I was in perfect health ; but whether my ceasing to dream was the effect of the recollection above mentioned, or of any change in the habit of my body, which is usual about that period of life, I cannot tell. I think it may more probably be imputed to the last. However, the fact was, that, for at least forty years after, I dreamed none, to the best of my remembrance ; and finding, from the testimony of others, that this is some- what uncommon, I have often, as soon as I awoke, endeavoured to recollect, without being able to recollect, anything that passed in my sleep. For some years past, I can sometimes recollect some kind of dreaming thoughts, but so incoherent that I can make nothing of them. " The only distinct dream I ever had since I was about sixteen, as far as I remember, was about two years ago. I had got my head blistered for a fall. A plaster, which was put upon it after the blister, pained me excessively for a whole night. In the morning I slept a little, and dreamed, very distinctly, that I had fallen into the hands of a party of Indians, and was scalped. " I am apt to think that, as there is a state of sleep, and a state wherein we are awake, so there is an intermediate state, which partakes of the other two. If a man peremptorily resolves to rise at an early hour for some interesting purpose, he will of himself awake at that hour. A sick- nurse gets the habit of sleeping in such a manner that she hears the least whisper of the sick person, and yet is refreshed by this kind of half sleep. The same is the case of a nurse who sleeps with a child in her arms. I have slept on horseback, but so as to preserve my balance ; and, if the horse stumbled, I could make the exertion necessary for saving me from a fall, as if I was awake. " I hope the sciences at your good uni- versity are not in this state. Yet, from so many learned men, so much at their ease, one would expect something more than we hear of." For the other letter, I am indebted to one of Dr Reid's most intimate friends, to whom it was addressed, in the year 1784, on occasion of the melancholy event to which it alludes. " I sympathize with you very sincerely in the loss of a most amiable wife. I judge of your feelings by the impression she made upon my own heart, on a very short ac- quaintance. But all the blessings of this world are transient and uncertain ; and it would be but a melancholy scene if there were no prospect of another. " I have often had occasion to admire the resignation and fortitude of young per- sons, even of the weaker sex, in the views of death, when their imagination is filled with all the gay prospects which the world presents at that period. I have been wit- ness to instances of this kind, which I thought truly heroic, and I hear Mrs G gave a remarkable one. " To see the soul increase in vigour and wisdom, and in every amiable quality, when health, and strength, and animal spirits decay — when it is to be torn by violence from all that filled the imagination and flattered hope — is a spectacle truly grand and instructive to the surviving. To .think that the soul perishes in that fatal moment when it is purified by this fiery trial, and fitted for the noblest exertions in another state, is an opinion which I cannot help looking down upon with contempt and dis- dain. " In old people, there is no more merit in leaving this world with perfect acquiescence than in rising from a feast after one is full. When I have before me the prospect of the infirmities, the distresses, and the peevish- ness of old age, and when I have already received more than my share of the good things of this life, it would be ridiculous indeed to be anxious about prolonging it ; but, when I was four-and-twenty, to have had no anxiety for its continuance, would, I think, have required a noble effort. Such efforts in those that are called to make them surely shall not lose their reward." I have now finished all that the limits of my plan permit me to offer here as a tribute to the memory of this excellent person. In the details which I have stated, both with respect to his private life and his scientific pursuits, I have dwelt chiefly on such cir- cumstances as appeared to me most likely to interest the readers of his works, by illustrating his character as a man, and his views as an author. Of his merits as an instructor of youth, I have said but little ; partly from a wish to avoid unnecessary diffuseness, but chiefly from my anxiety to enlarge on those still more important la- bours of which he has bequeathed the fruits to future ages. And yet, had he left no such monument to perpetuate his name, the fidelity and zeal with which he dis- charged, during so long a period, theobscure but momentous duties of his official station would, in the judgment of the wise and good, have ranked him in the first order of OF THOMAS REID, D.D. 35 useful citizens. " Nee enim is solus rei- publicse prodest, qui candidates extrahit, et tuetur reos, et de pace belloque censet ; sed qui juventutem exhortatur ; qui, in tanta bonorum praeceptorum inopia, virtute in- struit animos ; qui, ad pecuniam luxuri- anique cursu ruentes prensat ac retrahit, et, si nihil aliud, certe moratur : in privato, publicum nsgotium agit."* In concluding this memoir, I trust I shall be pardoned, if, for once, I give way to a personal feeling, while I express the satisfaction with which I now close, finally, my attempts as a biographer. Those which I have already made, were imposed on me by the irresistible calls of duty and attach- ment ; and, feeble as they are, when com- pared with the magnitude of subjects so splendid and so various, they have en- croached deeply on that small portion of literary leisure which indispensable engage- ments allow me to command. I cannot, at the same time, be insensible to the grati- fication of having endeavoured to associate, in some degree, my name with three of the greatest which have adorned this age — • Senaca," De Tranquill. An." cap. 3. happy, if, without deviating intentionally from truth, I may have succeeded, however imperfectly, in my wish to gratify at once the curiosity of the public, and to soothe the recollections of surviving friends. But I, too, have designs and enterprises of my own ; and the execution of these (which, alas ! swell in magnitude, as the time for their accomplishment hastens to a period) claims, at length, an undivided attention. Yet I should not look back on the past with regret, if I could indulge the hope, that the facts which it has been my province to record — by displaying those fair rewards of extensive usefulness, and of permanent fame, which talents and industry, when worthily directed, cannot fail to secure — may contribute, in one single instance, to foster the proud and virtuous independence of genius ; or, amidst the gloom of poverty and solitude, to gild the distant prospect of the unfriended scholar, whose laurels are now slowly ripening in the unnoticed pri- vacy of humble life. " I * On Reid's doctrines Mr Stewart has also 6ome j valuableobservationsin his" Dissertation on the Pro- gress of Metaphysical and Ethical Philosophy " — H. NOTES.* Note A. — Page 4. In the account given in the text of Dr Reid's ancestors, I have followed scrupu- lously the information contained in his own memorandums. I have some suspicion, however, that he has committed a mistake with respect to the name of the translator of Buchanan's History ; which would ap- pear, from the MS. in Glasgow College, to have been, not Adam, hut John. At the same time, as this last statement rests on an authority altogether unknown, (being written in a hand different from the rest of the MS.,i*) there is a possibility that Dr • If another edition of this Memoir should ever -be called for, I must request that the printer may adhere to the plan which I myself have thought advisable to adopt in the distribution of my notes. A mistake which has been committed in a late edi tion of my Lite of Dr Robertson, where a long Appendix is broken down into foot-notes, will suf- ficiently account for this request to those who have seen that publication. f It is to the following purport : — "The Historie of Scotland, first written in the Latm tungue by that famous and learned man, George Buchanan, and afterwards translated into theScottishe tungue by John Read, Esquyar, brother to James Rear), person of Banchory. Ternan, whyle he lived. They both.ly intered in the parish church of thattowne, seated not farre from the banke of the river of Deo, expecting the general resurrection, and the glorious appearing of Jesus Christ, there Rcdimer." The date Reid's account may be correct ; and, there- fore, I have thought it advisable, in a matter of so very trifling consequence, to adhere to it in preference to the other. The following particulars with respect to Thomas Reid may, perhaps, be acceptable to some of my readers. They are copied from Dempster, a contemporary writer ; whose details concerning his countrymen, it must, however, be confessed, are not always to be implicitly relied on : — " Thomas Reidus, Aberdonensis, pueri- tiaa me£e et infantilis otii sub Thoma Car- gillo collega, Lovaniiliterasinschola Lipsii* scrio didicit, quas magno nomine in Ger- mania docuit, carus Principibus. Londiui diu in comitatu humanissimi ac clarissiini viri, Fulconis Grevilli, Regii Consiliarii luterioris et Anglise Proqusestoris, egit : turn ad araicitiam Regis, eodem Fulcmie tlcducente, cveotus. inter Palatinos admis- of the transcript is 12th December lG.'i4. Accord- ing to CalderwoocVs IMS. History of the Chinch of Scotland, John Read was ''servitor and writer to Mr George Buchanan." But this is not likely.— H. » This is doubtful ; for Sir Robert Aytoun, in the account he gives of Reid's studies, makes no mention of so remarkable a circumstance. Dempster possibly confuted Thomas Reid with Reid's friend, Sir Thomas Seghet, another learned and wardering Scotchman, and a favourite pupil of '■• the Prince of Latin Let. ters."— H. D2 36 ACCOUNT OF THE LIFE AND WRITINGS sus, A Uteris Latinis Regi fuit. Scripsit multa, ut est magna indole et varia erudi- tione," &c. " Ex aula se, nemine conscio, nuper proripuit, dum illi omnia festinati honoris augmenta singuli ominarentur, nee quid deinde egerit aut quo Iocorum se con- tulerit quisquam indicare potuit. Multi stispicabantur, ta>dio aulse affectum, mon- asticte quieti seipsum tradidisse, sub an- num 1618. Rumor postea fuit in aulam rediise, et meritissimis honoribus redditum, sed nunquam id consequetur quod virtus promeretur. *' — Hist. Ecclesiastica Gentis Scotorum, lib. xvi. p. 576. What was the judgment of Thomas Reid's own times with respect to his genius, and what their hopes of his posthumous fame, may be collected from an elegy on his death by his learned countryman [Sir] Robert Aytoun. Already, before the lapse of two hundred years, some apology, alas ! may be thought necessary for an attempt to rescue his name from total oblivion. Aytoun's elegy on Reid is referred to in terms very flattering both to its author and to its subject, by the editor of the collec- tion entitled, " Poetarum Scotorum Museg Sacrae."* " Tn obitum Thomee Rheidi [Rhsedi] epicedium extat elegantissimum Robert! Aytoni, viri Uteris ac dignitate clarissimi, in Delitiis Poetarum Scotorum, ubi et ipsius quoque poemata, paucula qui- dem ilia, sed venusta, sed elegantia, corn- parent, "f * The well-known William Lauder.— H. t I add the following hricf notices, which T chance to have, in regard to this elegant scholar and acute philosopher. From Sir Robert Avtoun's Elegy, it appears, that, after finishing his studies in Scot- land. Reid proceeded to France. There, however, he did no' tarry ; for, as Pcottish-plulosophersiwere then in high academical repute, he soon received a cat! to Germany : — — — " attraxit Germania philtro E* precis et pretii." In that country, he taught philosophy and humane letters for several years with distinguished reputation, in the universities of Leipsic and Rostoch. ** Palladis in castris multa hie cum laude merentem, Kt victa de Barbarie sciolisque sophistis Ducentem insignes fama victrice triumphos Lipst'a dethmit lomum. Quis credidit illic Se rite admissum in Phcebi sacraria, Rha;do Non pandente fores? Quh per dumeta Lycsei Ausus itertentare, nisi duce et ausp'ce Rhaedo ? Nee tibi fama minor qua Balthica h'tora special Rosiocht'um, paucis istic tihi plurimus annis Crevit hono«, nullo non admirante profunda Doctrine aggestos tot in uno pectore acervos, Felicemque viani fandi,m to institute a suit with the magistrates of Aberdeen, about their management of the fund left by his ancestor for the librarian's salary, which fund had b?en greatly dilapidated by them since 1677. This was, however, rendered unnecessary by a decision of the Court of Session, which deprived them of the patronage of that office, and Te^ored it to the persons in whom the Secretary's will had vested it. Dr Reid appears from the College records, to have been in Dr G, Turnbull's class, (as Mr Stewart men- tions p. 4,) studying under him three sessions, and becoming A. M in 17v6. He entered college in 1122, and was in the first Grt-ek class taught by Dr Thomas B'ackwell, afterwards Principal, and celebrated, at the time, for his strenuous attempts to revive the study of the Greek language in the northern parts of Scotland Dr Reid had entered into this plan with enthu- siasm ; for his pupil and colleague, the late Professor William Ogilvie, used to relate that he had heard him recite to his class, demonstrations of Kuclidin the original language The sermon which was preached by Mr John Bis- aet, on the day of moderating a call for Dr Reid, (to the parish of- Now-Machar, near Aberdeen,) p. .% attracted much attention, and continued tobelonga favourite with the opponents of patronage. P. fi. Immediately on Dr He-id's appointment to the place of one of the Regents of King's College, he prevailed on his colleagues to make great improve- ments in their system of Univeisity education. The -es ion was extended fiom five to t>evyn month*. C 39 ] CORRESPONDENCE OF DR REID. The following correspondence consists of three consecutive series. The first, for which I am indebted to my friend, Alexander Thomson, Esq., of Ban- chory, extends from 1764 to 1770, and contains letters by Reid, during the first six years after his removal to Glasgow, to Dr Andrew Skene, and his son, Dr David Skene, physicians in Aberdeen. This correspondence was terminated, by the death of the father, in 1767, and of the son, in 1771. Both were highly eminent in their profession; but the latter, who hardly reached the age of forty, was one of the most zealous culti- vators of the natural sciences in Scotland, and the valued correspondent of Linnaeus, Pennant, Lord Karnes, and other distinguished contemporaries. These letters afford what was perhaps wanting to Mr Stewart's portraiture of Reid— they shew us the philo. sopher in all the unaffected simplicity of his character, and as he appeared to his friends in the familiar intercourse of ordinary life. The second series comprises the letters addressed to Lord Kames, as given in Lord Woodbouselee's Memoirs of the Life and Writings of that ingenious philosopher. They extend from 1772 to 1782, and are chiefly of scientific interest. The third series contains a selection from Reid's letters to his kinsman, the late Dr James Gregory, Professor of the Practice of Medicine in the University of Edinburgh. Dr Gregory is known, not only as a distinguished physician, but as one of the most elegant scholars and vigorous thinkers of his time. He was indeed a remarkable member even of a family in which, for two centuries, talent would almost seem to have been entailed. To Dr Gregory and Mr Dugald Stewart, Reid appropriately dedicated his prin- cipal work — the " Essays on the Intellectual Powers." The correspondence, which is of varied interest, extends from 1783, and was only terminated by Reid's death in 1796. I owe my best thanks to John Gregory, Esq., for the flattering manner in which he placed these valuable letters at my disposal ; but my friend Dr Alison is not the only other member of the family for whose kindness I have also to express my obligation — H. A.— LETTERS TO DRS ANDREW AND DAVID SKENE. TO DR ANDREW SKENE. Glasgow, Nov. Uth, 1764. Dear Sir, — I have been for a long time wishing for as much leisure as to write you, if it was only to revive the memory of the many happy hours which I have enjoyed in your company, when, tete-a- tete, we sat down to speak freely of men and things, without reserve and without malignity. The time slipt away so smoothly, humanity classwas added, on a higher scale than had been taught previously ; and the teaching of the ele- ments of Latin, by the Professor of Humanity, dis- continued ; some of the small bursaries were united ; and an account of these alterations was given to the public in a small tract, published in 1754. Dr Reid was in favour of one professor teaching thewhole, or the greater part of the curriculum, and Iherefore did not follow the plan of confining the professors to separate branches, as had been done in Glasgow since 1727, and in Marischal College since 1753 The plan ol'a seven mouths' session, after a trial of five years, was abandoned. that I could often have wished to have dipt its wings. I dare not now be guilty of any such agreeable irregularities ; for I must launch forth in the morning, so as t > be at the College (which is a walk of eight minutes) half an hour after seven, v hen I speak for an hour, without interruption, to an audience of about a hundred. At eleven I examine for an hour upon my morning prelection ; but my audience is little more than a third part of what it was in the morning. In a week or two, I must, for three days in the week, have a second pre- lection at twelve, upon a different subject, where my audience will be made up of those who hear me in the morning, but do not attend at eleven. My hearers commiily attend my class two years at least. The first session they attend the morning pre- lection, and the hour of examination at eleven ; the second and subsequent years tliey attend the two prelections, but. not the hour of examination. They pay fees for the first two years, and then they arc civci 40 CORRESPONDENCE OF DR 11EID. of that class, and may attend gratis as many years as they please. Many attend the Moral Philosophy class four or five years ; so that I have many preachers and students of divinity and law of considerable stand- ing, before whom I stand in awe to speak without more preparation than I have leisure for. I have a great inclination to attend some of the professors here — several of whom are very eminent in their way ; but I cannot find leisure. Much time is consumed in our college meetings about business, of which we have commonly four or five in the week. We have a literary society once a-week, consisting of the Masters and two or three more ; where each of the members has a discourse once in the session. The Professors of Hu- manity, Greek, Logic, and Natural Philo- sophy, have as many hours as I have, some of them more. All the other professors, except one, teach at least one hour a-day ; and we are no less than fourteen in num- ber. The hours of the different professors are different so far as can be, that the same student may attend two or three, or per- haps more, at the same time. Near a third part of our students are Irish. Thirty came over lately in one ship, besides three that went to Edinburgh. We have a good many English, and some foreigners. Many of the Irish, as well as Scotch, are poor, and come up late, to save money ; so that we are not yet fully conveened, although I have been teaching ever since the 10th of October. Those who pretend to know, say that the number of students this year, when fully conveened, will amount to 300. The Masters live in good habits with one another, and manage their political differ- ences with outward decency and good man- ners, although with a good deal of intrigue and secret caballing when there is an elec- tion. I have met with perfect civility from them all. By this time, I am sure you have enough of the College ; for y ou kno w as m uch as I can tell you of the fine houses of the Masters, of the Astronomical Observatory, of Kobin Fowlis' collection of pictures and painting college, of the foundery for types and printing house ; therefore, I will carry you home to my own house, which lyes among the middle of the weavers, like the Back Wynd in Aberdeen. You go through a long, dark, abominably nasty entry, which leads you into a clean little close You walk up stairs to a neat little dining-room, and find as many other little rooms as just accommodate my family so scantily that my apartment is a closet of six feet by eight or nine off the dining-room. To balance these little inconveniences, the house is new and free of buggs ; it has the best air and the finest respect in Glasgow ; the privilege of a large garden, very airy, to walk in, which is not so nicely kept but one may use free- dom with it. A five minutes' walk leads us up a rocky precipice into a large park, partly planted with firs and partly open, which overlooks the town and all the country round, and gives a view of the windings of the Clyde for a great way. The ancient cathedral stands at the foot of the rock, half of its height below you, and half above you ; and, indeed, it is a very magnificent pile. When we came here, the street we live in (which is called the Drygate) was infested with the smallpox, which were very mortal Two families in our neighbourhood lost all their children, being three each. Little David was seized with the infection, and had a very great eruption both in his face and over his whole body, which you will believe would discompose his mother. . Although my salary here be much the same as at Aberdeen, yet, if the class does not fall off, nor my health, so as to disable me from teaching, I believe I shall be able to live as easily as at Aberdeen, notwithstand- ing the difference of the expense of living at the two places. I have touched about A'70 of fees, and may possibly make out the hundred this session. And now, sir, after I have given you so full an account of my own state, spiritual and temporal, how goes it with you ? Are George and Molly minding their business ? I know Kate will mind hers. Is Dr David littering up your house more and more with all the birds of the air, the beasts of the field, and the clods of the valley ? Or has Walker, the botanist, been carrying him about to visit vegetable patients, while you are left to drudge among the animal ones ? Is your head steady, or is it sometimes [turning] round? I have a thousand ques- tions to ask about our [country] people, but I ought rather to put them to those who have more time to answer them. I was very sorry to hear, by a letter from Lady Forbes, of Hatton's misfortune, and am left in doubt whether the next account shall be of his death or recovery. The common people here have a gloom in their countenance, which I am at a loss whether to ascribe to their religion or to the air and climate. There is certainly more of religion among the common people in this town than in Aberdeen ; and, although it has a gloomy, enthusiastical cast, yet I think it makes them tame and sober. I have not heard either of a house or of a head broke, of a pocket picked, or of any flagrant crime, since I came here. I have not heard any swearing in the streets, nor seen a man drunk, (excepting, inter nos,one 1>n,f r,) since T came here. If this scroll LETTERS TO DRS A. AND D. SKENE. 41 tire you, impute it to this, that to-morrow is to be employed in choosing a Rector, and I can sleep till ten o'clock, which I shall not do again for six weeks ; and believe me to be, with sincere friendship .and regard, dear Sir, yours, Thomas Reid. II. TO DR DAVID SKENE. Dear Sir, — We had a Turin Professor of Medicine here lately, whom I wished you acquainted with : Count Carburi is his name ; an Athenian born, but has been most of his time in Italy.* He seems to be a great connoisseur in natural history, and has seen all the best collections in Europe. The Emperor and King of France, as well as many persons in Italy, he says, have much more compleat collections of our Scotch fossils than any we have in Britain. I described to him our Bennachie porphyry ; but he says all that they call porphyry in Italy, consists of small dark-coloured grains, in a grey ground, and has very much the same appearance as many of our granites, before it is polished. He wanted much to know whether we had any authentic evi- dence from Ireland, or anywhere else, of wood that had been seen in the state of wood, and afterwards petrified. He would have gone over to Ireland on purpose, if we could have given him ground to expect this. He says MM. Buffon and Daubenton are both positive that no such thing was ever known, and that all the petrified wood dug up on various parts of the earth — of whicli Carburi says he has two waggon -loads, found in Piedmont — has been petrified before our earth put on its present form ; and that there is no evidence of any such petrifica- tion now going on. I have a strong inclin- ation to attend the cbymical lecture here next winter ; but am afraid I shall not have time. I have had but very imperfect hints of Dr Black's theory of fire. He has a strong apprehension that the phlogistick principle is so far from adding to the weight of bodies, by being joyned to them, that it diminishes it ; and, on the contrary, by taking the phlogistick from any body, you make it heavier. He brings many experi- ments to prove this : the calcination of metals, and the decomposition of sulphur, you will easily guess to be among the num- ber ; but he is very modest and cautious in his conclusions, and wants to have them amply confirmed before he asserts them positively. I am told that Black's theory is not known at Edinburgh. . Chemistry * This was Count Mnrco, not fount Marino, Car- luiri ; horn at Ccpkalonia, and, Irom 1159 to 1808, Professor of Chemistry in I'adua.—M. seems to be the only branch of philosophy that can be said to be in a progressive state here, although other branches are neither ill taught nor ill studied. As Black is got into a good deal of practice, it is to be feared that hischymical inquiries must go on slowly and heavily in time to come. I never con- sidered Dollond's telescopes till I came here. I think they open a new field in op- ticks which may greatly enrich that part of philosophy. The laws of the refraction of light seem to be very different, in different kinds both of glass and of native chrystal. 1 have seen a prism of Brazil pebble, which forms two distinct speculums in Sir I. New- ton's experiment, each of them containing all the primary colours. A German native chrystal seemed to me to form four or five. One composition of glass separates the different colours much more than another composition, even with the same degree of refraction. Dollond has made a fortune by his telescopes, nobody else having attempted to imitate them, and is now, I am told, grown lazy. Nor is the theory of them prosecuted as it ought. Dollond's micro- meter is likewise a very fine instrument, although not built upon anything new in opticks. We have one of them here fitted to a reflecting telescope of about 18 inches, by which one may take the apparent diame- ter of the sun, or of any planet, within a second of a degree. I find a variety of things here to amuse me in the literary world, and want nothing so much as my old friends, whose place I cannot expect, at my time of life, to sup- ply. I think the common people here and in the neighbourhood greatly inferior to the common people with you. They are Boeotian in their understandings, fanatical in their religion, and clownish in their dress and manners. The clergy encourage this fanaticism too much, and find it the only way to popularity. I often hear a gospel here which you know nothing about; for you neither hear it from the pulpit, nor will you find it in the bible. What is your Philosophical Society* do- ing ? Still battling about D. Hume ? or have you time to look in ? I hope your papa holds out in his usual way. I beg to be remembered to him most affectionately, and to all the rest of your family. But I believe you do not like to be charged with compliments, otherwise I would desire of you likewise to remember me respectfully to Sir Archibald Grant, Sir Arthur and Lady Forbes, and others of my country « The Philosophical Society to which Reid here al udes was founded by himself and his relative, I)v John Gregory. It was vulgarly styled the Wine Club. Dr David Skene, who is called by Sir W. F. rbes " a prnsic'an ot genius and taste," was one of its original members, tee Forties's " Life of Beau tie," i. 35— H. 42 CORRESPONDENCE OF DR REID. acquaintance, when you have occasion to see them. I should be glad, too, to hear from you, when leisure, and opportunity, and the epistolary humour all meet together. My folks are' all pretty well, and beg their compliments to you and all yours. — I am, dear Sir, most affectionately, yours, Thomas Reid. Glasgow, 13 Jnh/ 1765, being the first warm day we have had since the month of May. III. TO DR DAVID SKENE. Glasgow, 20 Dec. 17«5. Dear Sir, — Your commissions have been lying by me some time, for want of a proper conveyance. An Aberdeen carrier promised to call for them, but disappointed me ; I therefore sent the two thermometers wrapt up in paper, and directed for you by Mr. Menzies, merchant in the Narrow Wynd, who was to set out from hence yes- terday morning. One has a circular bore in the small tube, the other an elliptical one, and is on that account much fitter for experiments. As there is a much greater quantity of quicksilver in the circular one, it may take four or five minutes to bring it to the temperature of a fluid in which it is immersed. For nice experiments, some of the elliptical ones are made by Dr Wil- son with the bulb of the small tube naked. But these are so liable to accidents that few choose them. The perspective machine goes to Edinburgh to-morrow with Dr Trail, who will send it to my sisters to be sent you by the first proper opportunity. . . . Mr Watt has made two small improve- ments of the steam-engine. The first is in the iron bars which support the fire. These have always been made of solid iron, and burn away so fast by the great heat, that the expense of repairing them comes to be very considerable. He uses hollow square bars of plate iron, always kept full of water, which communicates with a pretty large reservoir, so that the bars can never be heated above the degree of boyling water, and may be kept far below that degree of heat. The other improvement is to pre- vent the waste of heat by the chimney pipe of the furnace. It is evident that a very large proportion of the heat of the fire passes off in this way without being applied to the water in the boyler. To prevent this, he makes three small chimney pipes of iron, which are made to pass through the boyler. He is just now employed in setting up an engine for the Carron Company with these imp] ovements. Since I saw C. Carburi, I have it upon good authority that there are petrifying springs in England which petrify things put into them in a short time. And a gentleman here expects, in a short time, a petrified periwig from one of them. Dr Black tells me that Cramer's fur- naces, both for essaying and melting, as you have them described in his "Ars Dnci- masticn," are the best he knows. His are of this kind, being made of plate iron, lined with a coat of a lute, which is com- posed of one-part clay and three-parts fire- sand, which, he says, never cracks. He has not examined the Fechel earth, but con- jectures it to be a composition of the same kind with Prussian blue. He has seen a horse's head, which, by being long buried in a clay which had some mixture of iron, had in several places taken a fine blue tinge, or rather was covered with a fine blue dust. I have attended Dr Black's lectures hith- erto. His doctrine of latent heat is the only thing I have yet heard that is alto- gether new. And, indeed, I look upon it as a very important discovery. As Mr Ogilvie attended him and took notes, I believe he can give you a fuller account of it than I can. It gives a great deal of light to the phsenomena of heat that appear in mixture, solution, and evaporation ; but, as far as I see, it gives no light to those which appear in animal heat, inflammation, and friction. I wish this discovery may not reach any person who may be so ungene- rous as to make it public before the Dr has time to publish it himself. If the ac- count which Ogilvie can give you should suggest any doubts, I will be glad to clear them, so far as my knowledge of this doc- trine reaches. — I am very glad to hear that Dr Hope has a prospect of raising the true rhubarb. I believe I forgot to tell you that I wrapped up a head of what I take to be the daucus sylvesiris, in a piece of paper, and put it in the box with the drawing machine. It grows in great plenty in the fields here ; but I never saw it with you. I have not met with any botanists here. Our College is considerably more crowded than it was last session. My class, indeed, is much the same as last year ; but all the rest are better. I believe the number of our students, of one kind or another, may be between four and five hundred. But the College of Edinburgh is increased this year much more than we are. The Moral Philosophy class there, is more than double ours. The Professor, Ferguson, is, indeed, as far as I can judge, a man of a noble spirit, of very elegant manners, and has a very uncommon flow of eloquence. I hear he is about to publish, I don't know under what title, a natural history of man : exhibiting a view of him in the savage state, and in LETTEKS TO DKS A. AND D. SKENE 43 the several successive states of pasturage, agriculture, and commerce. Your friend, the Cte. de Lauraguais, was very full of you when he was here, and shewed an anxiety that your merit should be known. I am told that he has wrote many things in the Memoirs of the Academy ; but I know nobody here that has read them. Our College Library is ten or twelve years behind in the Memoirs of the Royal Aca- demy ; and all that the Cte. has wrote must fall within that period. He seems to have attached himself so entirely to chemistry as to have neglected every other branch of knowledge. Carburi was more universal ; he gave attention chiefly to the progress of manufactures and commerce, and to col- lect books and specimens of natural or artifi- cial things. Our society is not so harmonious as I wish. Schemes of interest, pushed by some and opposed by others, are like to divide us into parties, and, perhaps, engage us in law-suits.* When you see Mr W. Ogilvie, please make my compliments to him. I received his letter, and will write him when I can find leisure. I hope your papa is quite recovered of his cold, and that all the rest of the family are in good health. Pray, make my best compliments to him. Mrs Reid, Pegie, and I, have all had a severe cold and cough. I have been keeping the house these two days, in order to get the better of it. — I am, dear Sir, Yours most affectionately, Thomas Reid. Ended, Dec. 30. Wishing you many happy years. IV. TO DB ANDREW SKENE. Dear Sir, — I have been sometimes apt to impute it to laziness, and sometimes to hurry of business, that I have been so long without writing you. I am ashamed to plead the last of these excuses when I con- sider how many people there are of my acquaintance that have a great deal more to do than I have, a-nd would think all my business but idleness. Yet, I assure you, I can rarely find an hour which I am at liberty to dispose of as I please. The most disagreeable thing in the teaching part is to have a great number of stupid Irish teagues who attend classes for two or three years to qualify them for teaching schools, or being dissenting teachers. I preach to these as St Francis did to the fishes.-)- I • See above, p 40, A, below, pp. 46, A, and47, B. AH theory and all experience prove, that the worst and the most corrupt depositaries of acaderr'cal pa- tronage are a self-eleci ive body of professors.— H. t Not St Francis, but St Antony (of Padua.)— H. don't know what pleasure he had in his audience ; but I should have none in mine if there was not in it a mixture of reason- able creatures. I confess I think there is a smaller proportion of these in my class this year than was the last, although the number of the whole is not less. I have long been of the opinion, that, in a right con- stituted college, there ought to be two Pro- fessors for each class — one for the dunces, and another for those who have parts. The province of the former would not be the most agreeable, but, perhaps, it would require the greatest talents, and, therefore, ought to be accounted the post of honour. There is no part of my time more disagree- ably spent than that which is spent in College meetings, of which we have often five or six in a week. And I should have been attending one this moment if a bad cold I have got had not furnished me with an excuse. These meetings are become more disagreeable by an evil spirit of party that seems to put us in a ferment, and, I am afraid, will produce bad consequences. The temper of our northern colonies makes our mercantile people here look very grave. Several of them are going to Lon- don about this matter, to attend the pro- ceedings of Parliament. It is said that the effects in those colonies belonging to this town amount to above £400,000 sterling. The mercantile people are for suspending the stamp-act, and redressing the grievances of the colonists. Others consider their conduct as an open rebellion, and an avowed claim to independence, which ought to be checked in the beginning. They say that, for all their boasting, the colonists are a das- tardly, pusillanimous race, and that a Bri- tish fleet and army would soon reduce them to such terms as would secure their future dependence upon the mother country; that this is the most proper time for doing so when we are at peace with all our neigh- bours. In what light the House of Com- mons will view this matter, I don't know, but it seems to be one of the most import- ant matters that have come before them. I wish often an evening with you, such as we have enjoyed in the days of former times, to settle the important affairs of State and Church, of Colleges and Corpora- tions. I have found this the best expedient to enable me to think of them without melancholy and chagrin. And I think all that a man has to do in the world is to keep his temper and to do his duty. Mrs Reid is tolerably well just now, but is often ailing. She desires to be remembered to you and all your family.— I am, dear Sir, Yours most affectionately, Thomas Reid. Glasgou. Dec. 30, 1765. 44 CORRESPONDENCE OF DR IlEID. V. TO DK DAVID SKENE. Glasgow, 23 March 1766. Dear Sib,— I had yours of the 14th, and this moment that of Thursday the 20, with the inclosed, a letter from your papa by Mr Duguid, with your circular thermo- meter. I returned the thermometer, re- paired by Mr Annan, who left this two days ago, but was to be a week at Edinburgh in his return. I shall remember Sir Archi- bald Grant's commission, but must take some time to think of it. What would you think of Alex. Mearns in Gordon's Hospi- tal ? If you are not acquainted with him, you may learn his qualities, and tell me your sentiments. I shall likewise mind your ell 'ptical thermometer. Mr Stewart's* death affects me deeply. A sincere friendship, begun at twelve years of age, and continued to my time of life without any interruption, cannot but give you some pangs. You know his worth, yet it was shaded ever since you knew him by too great abstraction from the world- The former part of his life was more amiable and more social, but the whole was of a piece in virtue, candour, and humanity. I have often regretted that the sol icitude of pro viding for a numerous family, and the labour of managing an estate and a farm, should make a man in a great measure unknown, whose virtue, integrity, and judg- ment ought to have shone in a more exten- sive sphere. His scholars could not but observe and revere his virtues ; and I have no doubt but great numbers of them have reapedgreat improvement by him in matters of higher importance than mathematical knowledge. I have always regarded him as my best tutor, though of the same age with me. ■ If the giddy part of my life was in any degree spent innocently and virtuously, I owe it to him more than to any human creature ; for I could not but be virtuous in his company, and I could not be so happy in any other. But I must leave this pleas- ing melancholy subject. He is happy; and I shall often be happy in the remembrance of our friendship ; and I hope we shall meet again. There is no such thing as chymical fur- naces made here for sale. They are made of plate iron : and a white-iron-man manages that materia 1 better than a blacksmith. But you must direct them in everything, and be still over the work. I can give but an imperfect account of * John Stuart, Professor of Mathematics in Marischal College. This chair is in the presentation of the Town Council of Aberdeen j and on the va. cancy, by Stuart's death, Dr Hcid was appointed one of the examinators of c.imlidatc, for the oificc — H. the doctrine of latent heat ; but some hint I shall give, trusting entirely to your hououi that you will be cautious not to make any use of it that may endanger the discoverer being defrauded of his property. There is in every body a certain quantity of heat, which makes a part of its form or constitution, and which it never parts with without losing or changing its form. This is called the latent heat of that body. All or most bodies hare three different forms — hardness, fluidity, and steam or vapour. Take water, for an example, in its hard state, that of ice : we have no means of knowing what latent heat it may contain ; hut in its fluid state it has about 140° of latent heat more than it had in the state of ice. This heat is latent while the water is fluid ; it does not affect the thermometer, nor pro- duce any other effect but that of making the body fluid. In the very act of melting from the state of ice to that of water, 140° of heat is absorbed from the circumambient bodies without making the water sensibly warmer than the ice ; and in the act of passing from the state of water to that of ice, 140° of heat which was latent in the water becomes sen- sible, and must pass from the water to the ambient bodies before it can wholly be con- verted into ice. As there is no intermediate state between water and ice, a very small part of the water freezes at once ; and the latent heat of that part being communicated to the remaining water, the freezing even in the coldest air goes on piecemeal,' according as the latent heat goes off first into the water not yet frozen, and from that into the air or ambient bodies. Spermaceti, in passing from a solid to a perfectly fluid form, requires about 150° of heat, which becomes latent ; bees' wax about 160°. But there is this remarkable difference between these bodies — as well as iron and some other metals on the one hand, and water on the other — that the former soften by degrees, so that there are many intermediate degrees of softness be- tween the hardest state which the body takes by cold, and the state of perfect fluidity ; whereas in water there seems to be no intermediate degree between perfect ice and perfect water. Accordingly, in spermaceti, bees' wax, and iron, the latent heat is more or less, according to the de- gree of softness ; but in water it is always the same. As water has about 140° of latent heat more than ice, so steam has about 800° of latent heat more than water ; hence, an ounce of steam, though it have little more sensible heat than boyling water, will heat the cold water that condenses it almost as much as four ounces of boyling water would do. I can only at present give you an experiment or two of the many by which this theory is confirmed. But LETTERS TO DItS A. AND D. SKENE. 45 first, it is proper to observe, that equal quantities of the same fluid of different temperatures, being mixed, the tempera- ture of the mixed fluid is always an arith- metical mean between the temperatures of the ingredients. Thus, if a pound of water of 40° be mixed with a pound of 100", the mixed is found precisely 60°. This has been tried in an infinite variety of cases, and found to hold invariably, proper allowance being made for the heat communicated to the vessels, or drawn from them in the operation. Experiment 1. — Two Florence flasks had six ounces of water put into each. In one it was made to freeze ; in the other brought as near as possible to the freezing point without freezing — that is, to about 33°. Both were set to warm in a large warm room. The unfrozen water soon came to the temperature of the room ; but the frozen water took eleven or twelve hours to dis- solve, and for the greatest part of that time was not sensibly heated. A calculation was made upon the supposition that the frozen water had as much heat communi- cated to it every half hour as the unfrozen water had the first half hour. The result of this calculation was, that the frozen water had absorbed 136° or 140° of heat in melting, over and above that which affected the thermometer. Exp. 2. — Six ounces of ice of the tem- perature of 32° had six ounces of boyling water poured upon it. The ice melted im- mediately, and the whole water was 52" temperature. Exp. 3. — From Mussehenbroek, with a little variation. When the air is ten degrees below the freezing point, set a deep, narrow beer-glass of water to freeze, and let it re- main perfectly at rest, without the least motion. The water will cool regularly below 32° without freezing, even to 22° ; but, as soon as it is disturbed, a number of icy spicuke are formed ; and in the same moment the sensible heat rises to 32°, and continues so till all is frozen. I need not tell you, that by sensible heat is meant that which diffuses itself to the ambient bodies till all are brought to an equilibrium. Of this the thermometer is the measure. But latent heat adheres to the body without any tendency to diffuse itself to other bodies, unless they are able to change the foim of the body from vapour to a fluid, or from a fluid to ice or hardness — then the latent heat goes off to other bodies, and becomes sensible. I hope you will un- derstand me, though I have wrote in a great hurry. Yet I cannot find that Cullen or the Edinburgh people know anything of this matter. I may give you more of the ex- periments afterwards. Thomas Reid. VI. TO DR DAVIO SKENE. Glusiiaw, \8th April [17G6.] Dear Sir, — There is like to be a vacancy in one of the medical professions of this col- lege, by the removal of Joseph Black to Edinburgh. I thought, when I heard of D^Whlte's (death, that there was very little probability of our losing Dr Black by that event ; because the Chymical Profession in Edinburgh was that which was thought fittest for l>r Black ; and there was good reason to think that Cullen would not give up the Chemistry for the Theory of Medi- cine — though he would very willingly, ex- change it for the Practice of Medicine. But I was informed late yesternight, that Dr Black is willing to accept of the Theory of Medicine in Edinburgh, and that the Council are certainly to present him. I am very dubious whether his place here would be worth your acceptance ; but I am sure it would be so much the interest of this society to have such a man in it, (and I need not say how agreeable it would be to me,) that I beg leave to inform you of what 1 know of the state of the matter, that you may think of it, and let me know your thoughts. The salary of Dr Black's place, is £50 as Professor of the Theory and Practice of Medicine ; and the presentation is in the Crown. The recommendation of the College would probably have great weight, if unanimous ; but I think there is no pro- bability of an unanimous recommendation ; so that the Court interest must probably determine it. Dr Black, and Dr Cullen be- fore him, had £20 yearly from the College, for teaching chemistry ; and the College have, from time to time, allowed, I believe, above £500 for a laboratory. The chemical class this session might bring £50 or £60 of fees, and the medical class from £20 to £30 ; so that the whole salary andfees will be between £140 and £160. At the same time, the College can at any time withdraw the £20, and give that and the chemical laboratory to another ; and it is not improbable that this may be done if one be presented of whose abilities in chemistry the College is not satisfied. Dr Black, of late, had got a great deal of practice in the medical way, so as to leave him but little time for prose- cuting his chemical discourses, and I think you might expect the same after some time ; for he had no natural connection here : it was his merit alone that brought him into it ; and he long resisted, instead of courting it ; so that it was in a manner forced upon him. The other medical Professor has anatomy and botany for his province ; he has a good anatomical class ; but ho Joes 4(5 CORRESPONDENCE OF DR REID. not teach botany at all, nor is, as I appre- hend, qualified to teach it. All I have far- ther to say is, that there is a great spirit of inquiry here among the young people. Lite- rary merit is much regarded ; and I con- ceive the opportunities a man has of improv- ing himself are much greater than at Aber- deen. The communication with Edinburgh is easy. One goes in the stage-coach to Edin- burgh before dinner ; has all the afternoon there ; and returns to dinner at Glasgow next day : so that, if you have any ambition to get into the College of Edinburgh, (which, I think, you ought to have,) I conceive Glasgow would be a good step. Now, sir, if you incline this place, you must, without delay, try your interest at Court, and get the best recommendations you can to the members of this College. The Principal and Mr Clow are not engaged ; they are the only persons to whom I have made known, or intend to make known, my writing to you. Lord Findlater's interest, I think, would have weight with Trail and Williamson. I am told of three candidates — Dr Stevenson, in Glasgow; Dr Smith Carmichael, a young doctor, presently at London ; and one Dr Stork, who was educated here. Each of these, I apprehend, has interest with some of the members, and depend upon them ; so that we will probably be divided, and, con- sequently, our recommendation, if any is given, will have little weight at Court. If, after due deliberation, you think it not worth your while to stir in this matter for yourself, will you be so good as communicate the state of the case to Dr George Skene ?" He is the man — that is, next to you — I would be fond of for a colleague ; and in this I think I am determined more by the public good than my private. VII. TO DR ANHREW SKENE. Dear Sir, — I cannot presently lay my hand upon the last letter I had from you, and I beg you will impute it to that and to my bad memory if there was anything in it I ought to answer. I have sent by the bearer, Mr Duguid, merchant in Aberdeen, an elliptical thermometer for Dr David, which I could not find an opportunity of sending till now. Mrs Reid was, this day, at one in the afternoon, brought to bed of a daughter, whom we have named Elizabeth, and I hope is in a good way We have had great canvassing here about * A third Aberdonian rhysican of distinction, ot the name of Skene, but not a relation, at least not a near relation, of the other two He was Prol'essoi of Philosophy, Marischal ( ollege; an eminent scholar ; and father of the late Solicitor-General — H. a Professor of the Theory and Practice of Physic, to succeed Dr Jo. Black, although all that we do is to recommend one to the King, who has the presentation. Dr Stevenson, a son of the late Dr Stevenson in Edinburgh, who has by much the best practice in this town and neighbourhood, has obtained a recommendation from the majority of the College, not without much interest. The only objection to him was his great practice, which it was thought might tempt him to neglect regular teach- ing. And, I believe, the majority would have preferred to him any man of character who had not such a temptation to neglect the duties of his office. However, the strongest assurances that he would not ne- glect the class — nay, that he would think himself bound in honour to give up the Profession if he could not keep up a class, brought in a majority to sign a recom- mendation in his favour ; and, as he has a strong interest at Court, and no rival, as far as we know, it is thought he will be the man. He declines teaching the chemistry class, which is in the gift of the College, and, I conceive, will be given to one of Dr Black's scholars. My class will be over in less than a month, and by that time I shall be glad to have some respite. I hope to have the pleasure of seeing my friends at Aberdeen in the month of August, if not sooner. We have had a thronger College this year than ever before. I had some reason to think that I should not have so good a class as last year, and was dis- appointed, for it was somewhat better. I expect a good one next winter, if I live so long. The Irish, on whom we depend much, have an ebb and flow, as many of them come but one year in two. We have been remarkably free from riots and dis- orders among the students, and I did not indeed expect that 350 young fellows could have been kept quiet, for so many months, with so little trouble. They commonly attend so many classes of different profes- sors, from half-an-hour after seven in the morning till eight at night, that they have little time to do mischief. You'll say to all this that cadgers are aye speaking of crooksaddles. I think so they ought ; besides, I have nothing else to say to you, and I have had no time to think of anything but my crooksaddles for seven months past. When the session is over I must rub up my mathematicks against the month of August. There is one candidate for your Profession of Mathematicks to go from this College ; and, if your College get a. better man or a better mathematician, they will be very lucky. I am so sensible of the honour the magistrates have done me in naming me to be one of the examinators, that I will not decline it, though, I confess, LETTERS TO DRS A. AND D. SKENE. 47 I like tlie honour better than the office.- I am, dear Sir, Yours most affectionately, Thomas Reid. Glasgow, 8th May, 1766. Half an hour after eleven at night. VIII. TO DR ANDREW SKENE. When you are dis-- posed to laugh you may look into the in- closed proposals from a physician here who has been persecuting everybody with an edition of Celsus, and now with an index to him as large as the book. Another physi- cian here is printing a History of Medicine, and of all the arts and sciences from the beginning to the present time, four vols. 8vo, price one guinea. He is not thought mad, but whimsical. I have not the pro- posals to send you, and I suppose I have sent enough of this kind. We authors had rather be known for madmen or fools than pass our lives in obscurity. Stevenson's presentation to the Profession of Medicine here is not yet come, but is expected as cer- tain. The College have appointed a Lec- turer in Chemistry, and one in Materia Medica, for next session. I think we might have a college of medicine here if we had an infirmary. I think our surgeons eclipse our M.D's. I do not hear much of the last, if you except Black and Stevenson. Our Professor of Anatomy is not an M.D., otherwise I would have excepted him also. Have you ever tried the seeds of the dau- cus sylvestris in nephritick cases ? It has been much talked of of late. I never saw it in the north, but it is pretty common in the fields here. — I am, dear Sir, Yours most affectionately, Thomas Reid. Glasgow, \5th July 1766. IX TO DR ANDREW SKENE. Glasgow College, Dec. 17, 1766. • • « I live now in the College, and have no distance to walk to my class in dark mornings, as I had before. I enjoy this ease, though I am not sure whether the necessity of walking up and down a steep hill three or four times a-day, was not of use. I have of late had a little of your distemper, finding a giddiness in my head when I lie down or rise, or turn myself in my bed. Our College is very well peopled this session ; my public class is above three score, besides the private class. Dr Smith never had so many in one year. There is nothing so uneasy to me here as our fac- tions in the College, which seem to be rather more inflamed than last session. Will you take the trouble to ask of Dr David, whether he knows of a bird called a stankhen.* It is a water fowl, less than a duck, with scolloped membranes at the toes, but not close-footed, and has a crest on the forehead of the same kind of sub- stance with a cock's comb, but white andflat. It has a very fishy taste, and is found here in the lochs. If he has none of this kind, I could send him one when I find a proper occasion. I am, with entire affection and regard, dear Sir, yours, Thomas Reid. X. TO DR DAVID SKENE. Glasgow College, 25th Fehy. 1767. Dear Sir, — I intend to send your stank- hen along with the furnace, which was ready long ago, and I suppose would have been sent before now, but that Dr Irvine was confined a long time by a megrim, and was like to lose one eye by it ; but is now pretty well recovered, and intends to send your furnace this week. Since the repeal of the stamp-act, trade, which was languishing, has revived in this place, and there is a great bustle and great demand for money. We are now resolved to have a canal from Carron to this place, if the Parliament allows it. £40,000 was subscribed last week by the merchants and the Carron Company for this purpose ; and commissioners are immediately going up to London to apply for an act of Parlia- ment. The freight upon this canal is not to exceed twopence per ton for every mile ; the land carriage is more than ten times as much. Our medical college has fallen off greatly this session, most of the students of medi- cine having followed Dr Black ; however, our two medical professors and two lec- turers have each of them a class, and Irvine expects a great many to attend him for botany in summer. The natural and moral philosophy classes are more numerous than they have ever been ; but I expect a great falling off, if I see another session. The Lecturer in Chemistry has general approba- tion. He chiefly follows Dr Black and Stahl. There is a book of Stahl's, called " Three Hundred Experiments," which he greatly admires, and very often quotes. I was just now seeing your furnace along with * The Gallinula Chloropus — H. 48 CORRESPONDENCE OF DR REID. Irvine ; I think it a very decent piece of furniture for a man of your profession, and that no limb of the faculty should be without one, accompanied with a proper apparatus of retorts, cucurbits, &c. For my part, if I could find a machine as proper for ana- lyzing ideas, moral sentiments, and other materials belonging to the fourth kingdom, I believe I should find in my heart to be- stow the money for it. I have the more use for a machine of this kind, because my alembick for performing these operations — I mean my cranium — has been a little out of order this winter, by a vertigo, which has made my studies go on heavily, though it has not hitherto interrupted my teaching I have found air and exercise, and a clean stomach, the best remedies ; but I cannot command the two former as often as I could wish. I am sensible that the air of a crowded class is bad, and often thought of carrying my class to the common hall ; but I was afraid it might have been construed as a piece of ostentation. I hope you are carrying on your natural history, or something else, in the Club, with a view to make the world wiser. What is my Lord Linnaeus doing ? Are we ever to expect his third volume upon the fossile kingdom or not ? "We are here so busie reading lec- tures, that we have no time to write. . . . XI. TO DR DAVID SKENE. Glasgow College, 14 SepK 1767. Dear Sir, — It gives me much surprise, as well as affliction, to hear frommy daughter Patty, of the death of my dear friend, your papa. Fifteen years ago it would havebeenno surprise ; but for some years back, I thought there was great probability that his life and usefulness might have had a longer period. I can never, while I remember anything, forget the many agreeable hours I have en- joyed with him in that entire confidence and friendship which give relish to life. I never had a friend that shewed a more hearty affection, or a more uniform dispo- sition to be obliging and useful to me and to my family. I had so many opportuni- ties of observing his disinterested concern to be useful in his profession to those from whom he could expect no return, his sym- pathy with the distressed, and his assiduity in giving them his best assistance, that, if I had had no personal friendship with him, I could not but lament his death as a very great and general loss to the place. It is very uncommon to find a man that at any time of life, much more at his, possessed the active, the contemplative, and the social disposition at once in so great vigour. I sincerely sympathize with you ; and I beg you will assure each of your brothers and sisters of my sympathy ; and that, besides my personal regard to every one of them, I hold myself to be under the strongest obligation from gratitude and regard to the memory of my deceased friend, if I can ever be of the least use to any of them. You are now, dear Sir, in the providence of God, called to be a father as well as a brother ; and I doubt not but you will ac- quit yourself in that character as you have done in the other. I need not say that Dr Skene's death gave very great affliction to Mrs Reid and to all my family ; they all desire that you and all your family may be assured of their respect and sympathy. . . . Some days after I parted from you at Edinburgh, I was called home to do the last duty to my sweet little Bess, whom I had left in perfect health some days after her innoculation. Since that time I have not been three miles from Glasgow, but once at Hamilton with Mr Beattie. Hav- ing my time at command, I was tempted to fall to the tumbling over books, as we have a vast number here which I had not access to see at Aberdeen. But this is a mare magnum, wherein one is tempted, by hopes of discoveries, to make a tedious voy- age, which seldom rewards his labour. I have long ago found my memory to be like a vessel that is full ; if you pour in more, you lose as much as you gain ; and, on this aceount, have a thousand times resolved to give up all pretence to what is called learn- ing, being satisfied that it is more profitable to ruminate on the little I have laid up, than to add to the indigested heap. To pour learning into a leaky vessel is indeed a very childish and ridiculous imagination. Yet, when a man has leisure, and is placed among books that are new to him, it is difficult to resist the temptation. I have had little society, the college people being out of town, and have almost lost the faculty of speech by disuse. I blame my- self for having corresponded so little with my friends at Aberdeen. I wished to try Linnoeus's experiment, which you was so good as to communicate to me. I waited for the heat of summer, which never came till the first of August, and then lasted butia few days. Not hav- ing any of the fungus powder at hand, I put a piece of fresh fungus which grew on rot- ten wood in pure water. In a day or two I found many animalcules diverting them- selves in the water by diving and rising again to the top. But, after three or fouT days, the water turned muddy and stunk. And, from all I could then observe, I should rather have concluded that my animalcules died and putrified, than that they were transformed into youug mushrooms. I see LETTERS TO DRS A. AND D. SKENE. 49 r letter in The Edinburgh Courant of Wed- nesday last on this subject. About twenty hours ago, I put some smutty oats in water ; but have not seen any animals in it yet. A nasty custom I have of chewing tobacco has been the reason of my observ- ing a species of as nasty little animals. On the above occasion, I spit in a bason of saw- dust, which, when it comes to be drenched, produces a vast number of animals, three or four times as large as a louse, and not very different in shape ; but armed with four or five rows of prickles like a hedgehog, which seem to serve it as feet. Its motion is very sluggish. It lies drenched in the foresaid mass, which swarms with these animals of all ages from top to bottom ; whether they become winged at last I have not discovered. Dr Irvine was taken up a great part of the summer with his botanical course ; and, since that was over, has been in the country. I have gone over Sir James Stewart's great book of political ceconomy, wherein I think there is a great deal of good materials, care- lessly put together indeed ; but I think it contains more sound principles concerning commerce and police than any book we have yet had. We had the favour of a visit from Sir Archibald Grant. It gave me much pleasure to see him retain his spirits and vigor. I beg when you see him you will make my best compliments to him. I beg to be remembered to the Club, which I hope goes on with spirit. I am, with great regard, dear Sir, yours most affectionately, Thomas Reid. Be so good as to put the inclosed into Sandie Leslie's shop. XII. TO DR DAVID SKENE. Dear Sir, — You will easily guess that my chief motive in writing you at this time, is, by the benefit of your frank, to save the postage of the two inclosed, of which I give you the trouble. Perhaps I would have dis- sembled this, if I had had anything to say. I long to hear how Linnaeus' experiment has succeeded with you. For my own part, I have found nothing aboutit but what I wrote you before. The chyniists here are hunting for something by which cambrick may be stamped as it comes from the loom, so that the stamps shall stand out all the operations of boyling, bleaching, &c. The only thing that is like to answer, I am told, is that solu- tion of silver which is used to dye ivory black. The act of Parliament anent cambrick re- quires it to be stamped in the loom ; and, if this stamp is not apparent after bleaching, it is contraband. But the wisdom of the nation has not thought fit to prescribe the material to be used for that purpose ; if no such material is found, the act will be use- less. I passed eight days lately with Lord Kaims at Blair-Drummond. You were very honourably mentioned. My Lord has it much at heart to have a professor of practical mcchanicks established at Edin- burgh, and wants only a proper person. He is preparing a fourth edition of his " Elements." I have been labouring at Barbara Celarent for three weeks by- gone ;* and on Monday begin my own course. I do not expect such a crop of students as 1 had last year ; but the Col- lege in general promises pretty well. My compliments to all your family ; and believe me to be, with great affection, dear Sir, Yours, Thomas Reid. Glasgow College, 31 Oct. 17G7- XIII. TO DR DAVID SKENE. [j„i y mo.\ Peak Sir, — Having this opportunity, I could not forbear asking how you do, and what you are doing. I know you are giv- ing feet to the lame, and eyes to the blind, and healing the sick. I know you are gathering heaps of fossils, vegetables, and animals, and I hope among other fossils you are gathering gold and silver; this is all very right. I know, likewise, that you have been, ever since you was in petticoats, most avari- ciously amassing knowledge. But is it all to die with you, and to be buried in your grave ? This, my dear sir, ought not to be. You see we Scotch people will be blotting paper though you should hold your hand : stultnm est periturtB parcere churae. Can you find no time, either when you are laid up in the gout, or when the rest of the world is in good health, to bequeath something to pos- terity ? Think seriously of this, if you have not done so already. Permit me, sir, to offer you another counsell ; for you know we moralists know better how to give good counsell than to take it. Is it not possible for you to order things so as to take a jaunt of six weeks or two months ? I verily believe there are things worth knowing here, much more at Edinburgh, of which you cannot be fully informed while you keep be-north Tay. We have speculatists in medicine, in chem- istry, in mechanics, in natural history, that are worth being acquainted with, and that * This alludes to his " Analysis of Aristotle's Lo- gic," which he was then preparing as an Appendix to one of Lord Karnes's " Sketches ofthe History of Man "— H. 50 CORRESPONDENCE OF DR REID. would be fond of your acquaintance. As to myself, the immaterial world has swal- lowed up all my thoughts since I came here ; but I meet with few that have travelled far in that region, and am often left to pursue my dreary way in a more solitary manner than when we used to meet at the club. What is Linmeus doing ? When you have leisure, indulge me with the pleasure of knowing that you have not forgot, dear Sir, your affectionate friend, Thomas Reid. B— LETTERS TO LORD KAMES. ON THE DOCTRINE OF NECESSITY IN RELA- TION TO MORALS. Glasgow College, 3d D c. 1772. My Lord, — I was very glad to under- stand, by the letter you honoured me with of November 9, that you got safe home, after a long journey, in such dreadful rainy weather. I got to Mr C 's on horse- back soon after you left me, where I was in good warm quarters. The case you state is very proper, to dis- cover how far we differ with respect to the influence of the doctrine of necessity upon morals. A man in a mad fit of passion stabs his best friend ; immediately after, he condemns himself; and, at last, is condemned by a court of justice, although his passion was no less irresistible than if he had been pushed on by external violence. My opinion of the case, my Lord, is this : if the passion was really as irresistible as you represent it, both in its beginning and progress, the man is innocent in the sight of God, who knows that he was driven as by a whirlwind, and that, the moment he was master of himself, he abhorred the action as much as a good man ought to do. At the same time, he reasonably may condemn himself, and be condemned by a court of justice. He condemns himself, because, from his very constitution, he has a conviction that his passion was not irresistible. Every man has this conviction as long as he be- lieves himself not to be really mad, and incapable of self-government. Even if he is a fatalist in speculation, that will not hinder this natural conviction when his conscience smites him, anymore than specu- lative scepticism will hinder a man from apprehension of danger when a cart runs against him. The court of justice condemns him for the same reason, because they believe that his passion was not irresistible. But, if it could be proved that the man was really incapa- ble of bridling his passion — that is, that he was really mad — then the court of justice ought not to punish him as a criminal, but to confine him as a madman. "What is madness, my Lord ? In my opinion, it is such weakness in the power of self-government, or such strength of pas- sion, as deprives a man of the command of himself. The madman has will and inten- tion, but he has no power to restrain them. If this madness continues so long as to be capable of proof from the tenor of a man's actions, he is no subject of criminal law, because he is not a free agent. If we sup- pose real madness to continue but for a moment, it makes a man incapable of a crime, while it lasts, as if it had continued for years. But a momentary madness can have no effect to acquit a man in a court of justice, because it cannot be proved. It would not even hinder him from condemn- ing himself, because he cannot know that he was mad. In a word, if, by a mad fit of passion, your Lordship means real madness, though temporary, and not permanent, the man is not criminal for what this fit of madness produced. A court of justice would not impute the action to him, if this could be proved to be the case. But if, by a mad fit of passion, you mean only a strong pas- sion, which still leaves a man the power of self-government, then he is accountable for his conduct to God and man ; for every good man — yea, every man that would avoid the most heinous crimes— must at some times do violence to very strong passions. But hard would be our case indeed, if we were required, either by God or man, to resist irresistible passions. You think that will and intention is suf- ficient to make an action imputable, even though that will be irresistibly determined. I beg leave to dissent, for the following reasons : — 1 An invincible error of the understanding, of memory, of judgment, or of reasoning, is not imputable, for this very reason, that it is invincible : why, then, should an error of the will be imputable, when it is supposed equally invincible ? God Almighty has given us various powers of understanding and of will. They are all equally his workmanship. Our LETTERS TO LORD KAMES. 51 understandings may deviate from truth, as our wills may deviate from virtue. You will allow that it would be unjust and tyran- nical to punish a man for unavoidable devi- ations from truth. Where, then, is the justice of condemning and punishing him for the deviations of another faculty, which are equally unavoidable ? You say we are not to judge of this mat- ter by reasons, but by the moral sense. Will you forgive me, my Lord, to put you in mind of a saying of Mr Hobbes, that when reason ss against a man. he will he against reason. I hope reason and the moral sense are so good friends as not to differ upon any point. But, to be serious, I agree with your Lordship, that it is the moral sense that must judge of this point, whether it be just to punish a man for doing what it was not in his power not to do. The very ideas or notions of just and un- just are got by the moral sense ; as the ideas of blue and red are got by the sense of seeing. And as by the sense of seeing we de- termine that this body is red, and that is blue ; so, by the moral sense, we determine this action to be just, and that to be unjust. Itisby the moral sense that I determine, in general, that it is unjust to require any duty of a man which it is not in his power to perform. By the same moral sense, in a particular case, I determine a man to be guilty, upon finding that he did the deed voluntarily and with intention, without making any inquiry about his power. The way to reconcile these two determinations I take to be this : — that, in the last case, I take for granted the man's power, because the common sense of man- kind dictates, that what a man did volun- tarily and with intention, he had power not to do: 2. A second reason of my dissent is, That the guilt of a bad action is diminished in proportion as it is more difficult to resist the motive. Suppose a man entrusted with a secret, the betraying of which to the ene- my may ruin an army. If he discloses it for a bribe, however great, he is a villain and a traitor, and deserves a thousand deaths. But, if he falls into the enemy's hands, and the secret be wrested from him by the rack, our sentiments are greatly changed; we do not charge him with vil- lany, but with weakness. We hardly at all blame a woman in such a case, because we conceive torture, or the fear of present death, to be a motive hardly resistible by the weaker sex. p- As it is, ^hereforejthe uniform judgment of mankind! that, where the deed is the same, andCTie will and intention the same, the degree of guilt must depend upon the difficulty of resisting the motive, will it not follow, that, when the motive is absolutely irresistible, the guilt vanishes altogether ? 3. That this is the common sense of mankind, appears further from the way in which we treat madmen. They have will and intention in what they do ; and, there- fore, if no more is necessary to constitute a crime, they ought to be found guilty of crimes. Yet no man conceives that they can be at all subjects of criminal law. For what reason ? for this, in my opinion, that they have not that power of self-command which is necessary to make a man account- able for his conduct. You suppose, my Lord, a physical power to forbear an action even when it is neces- sary. But this I cannot grant. Indeed, upon the system of free agency, I can easily conceive a power which is not exerted ; but, upon the system of necessity, there can be no such thing— every power that acts by necessity must be exerted. I do indeed think, that a man may act without a motive ; and that, when the mo- tives to action lie all on one side, he m.iy act in contradiction to them. But I agree with your Lordship, that all such actions are capricious ; and I apprehend that, if there were no actions of this kind, there could be no such thing as caprice, nor any word in language to signify it : for why should every language have a word to sig- nify a thing which never did nor can exist ? I agree also with your Lordship, that there can be no merit in such an action, even if it is innocent. But if it is vicious, it has the highest degree of demerit ; for it it is sinning without any temptation, and serving the devil without any wages. It ought to be observed, however, that a vir- tuous action can never becapricious; because there is always a just and sufficient motive to it. For, if I have no other mptive, I must at least have this, that is a worthy action, and is my duty ; which, in reason, ought to weigh down all motives that cai be put into the opposite scale. A capricious action may be innocent, and then it is folly ; or it may be vicious, and then it is pure wickedness. Liberty, like all other good gifts of God, may be abused. As civil liberty may be abused to licentiousness, so our natural liberty may be abused to caprice, folly, and vice. But the proper exercise of liberty is, after weighing duly the motives on both sides, to be determined, not by the strongest mo- tive, but by that which has most authority. It is of great importance in this matter, to distinguish between the authority of mo- tives and their force. The part that is decent, that is manly, that is virtuous, that is noble, has always authority upon its side. Every man feels this authority in his own breast ; and there are few men so wicked as not to yield to it when it has no antago- nist. E 2 CORRESPONDENCE OF DR REID. But pleasure, interest, passion, sloth, often muster a great force on the other side, which, though it has no authority, has often the greater power; and a, conflict arises between these opposite parties. Every man is conscious of this conflict in his own breast, and is too often carried down by the superior force of the party which he knows to have no authority. This is the conflict which Plato describes between reason and appetite ; this is the conflict which the New Testament describes between the spirit and the flesh. The op- posite parties, like Israel and Amalek, dis- pute the victory in the plain. When the self-determining power, like Moses upon the mount, lifts up its hand and exerts itself, then Israel prevails, and virtue is triumphant ; but when its hands hang down and its vigour flags, then Amalek prevails. I am, my dear Lord, most respectfully yours, Tho. Reid. II. ON THE MATERIALISM OF PRIESTLEY AND THE EGOISM OF FRENCH PHILOSOPHERS. r : 17 . 73 - Dr Priestley, in his last book, thinks that the power of perception, as well as all the other powers that are termed mental, is the result of such an organical structure as that of the brain. Consequently, says he, the whole man becomes extinct at death, and we have no hope of surviving the grave, but what is derived fiom the light of Revelation. I would be glad to know your Lordship's opinion, whether, when ray brain has lost its original structure, and when, some hun- dred years after, the same materials are again fabricated so curiously as to become an intelligent being, whether, I say, that being will be mc ;' or, if two or three such beings should be formed out of my brain, whether they will all be me, and conse- quently all be one and the same intelligent being. This seems to me a great mystery, hut Priestley denies all mysteries. He thinks, and rejoices in thinking so, that plants have some degree of sensation. As to the lower animals, they differ from us in degree only, and not in kind. Only they have no promise of a resurrection. If this be true, why should not the King's advocate be ordered to prosecute criminal b> riles, and " Our Engliih / being of an ambiguous sound, it would he convenient in psychology, could we occasion- ally employ me for a nominative, as the French do their moi But this nnt being the ease, Reid is here, a6 elsewhere in his letters, grammatically at fault. you criminal judges to try them ? You are obliged to Dr Priestley for teaching you one-half of your duty, of which you knew nothing before. But I forgot that the fault lies in the legislature, which has not givenyoulawsforthispurpose. I hope,how- ever,when anyof them shall be brought to a trial, that he will be allowed a. jury of his peers. I am not much surprised that your Lordship has found little entertainment in a late French writer on human nature.* From what I learn, they are all become rank Epicureans. One would think that French politesse might consort very well with disinterested benevolence ; but, if we believe themselves, it is all grimace. It is flattery, in order to be flattered ; like that of the horse, who when his neck itches, scratches his neighbour, that he may be scratched by him again. I detest all sys- tems that depreciate human nature. If it be a delusion, that there is something in the constitution of man that is venerable and worthy of its author, let me live and die in that delusion, rather than have my eyes opened to see my species in a humi- liating and disgusting light. Every good man feels his indignation rise against those who disparage his kindred or his country ; why should it not rise against those who disparage his kind ? Were it not that we sometimes see extremes meet, I should think it very strange to see atheists and high-shod divines contending as it were who should most blacken and degrade human nature. Yet I think the atheist acts the more consistent part of the two : for surely such views of human nature tend more to promote atheism, than to promote religion and virtue. ..... III. ON THE CONVERSION OF CLAY INTO VEGETABLE MOULD. October 1, 1775. The theory of agriculture is a wide and deep ocean, wherein we soon go beyond our depth. I believe a lump of dry clay has much the same degree of hardness, whether the weather be hot or cold. It seems to be more affected by moisture or drought : and to be harder in dry weather, and more easily broken when a little moistened. But there is a degree of wetness in clay which makes it not break at all when struck or pressed ; it is compressed and changes its figure, but does not break. Cla y grou nd, I think, ought to be ploughed • Helvetius, De I'Esprit — Loan WoomioiisELBB. Hardly; this work I'einf then, nearly twenty year old. Probably the work, " Sur.l Uommo."_H. LETTERS TO LORD KAMES. 53 in the middle state between wetness and dryness, for this reason : When too dry, the plough cannot enter, or cannot make handsome work. Those clods are torn up, which require great labour and ex- pense to break them. And unless they are broken, the roots of vegetables cannot enter into them. When too wet, the fur- row, in being raised and laid over by the plough, is very much compulsed, but not broken. The compression makes it much harder when it dries, than it would have been without that compression. But when the ground is neither too wet nor too dry, the farrow, in being raised and laid over by the plough, breaks or cracks with in- numerable crevices, which admit air and moisture, and the roots of vegetables. Clay, when exposed in small parts to the air, and to alternate moisture and drought, mellows into mould. Thus a clod of clay, which is so hard in seed-time that you may stand upon it without breaking it, will be found in autumn of the colour of mould, and so softened, that when you press it with the foot it crumbles to pieces. On some clays this change is produced in a shorter time, in the same circumstances ; others are more refractory, and require more time. If wet clay is put into the fire uncom- pressed, I am informed that it burns to ashes, which make no bad manure. But if the clay be wrought and compressed when wet, and then dried, and then put into the fire, it burns into brick, and with a greater degree of heat, into a kind of -glass. I These, my Lord, are facts ; but to deduce \ them from principles of attraction and re- pulsion, is beyond the reach of my philo- sophy : and I suspect there are many things in agriculture, and many things in che- mistry, that cannot be reduced to such principles ; though Sir Isaac Newton seems to have thought otherwise. Human knowledge is like the steps of a ladder. The first step consists of particular truths, discovered by observation or expe- riment : the second collects these into more general truths : the third into still more general- But there are many such steps before we come to the top ; that is, to the most general truths. Ambitious of know- ledge, and unconscious of our own weak- ness, we would fain jump at once from the lowest step to the highest ; but the conse- quence of this is, that we tumble down, and find that our labour must be begun anew. Is not this a good picture of a phi- losopher, my Lord ? I think so truly ; and I should be vain of it, if I were not afraid that I have stolon it from Lord Bacon. | I am, &c. ( Tho. Rkid. IV. ON THE GENERATION OP PLANTS AND ANIMALS. JVo date — but supposed 1775- My Lord, — I have some compunction for having been so tardy in answering the letter which your Lordship dtd me the honour to write me of the 6th November, especially as it suggests two very curious subjects of correspondence. But, indeed, my vacant time has been so much filled up with trifles of College business, and with the frequent calls of a more numerous class of students than I ever had before, that there was no room for anything that could admit of delay. Y ou have expressed with great elegance and strength the conjecture I hinted with regard to the generation of plants. I am indeed apt to conjecture, that both plants and animals are at first organized atoms, having all the parts of the animal or plant, but so slender, and folded up in such a manner, as to be reduced to a par- ticle far beyond the reach of our senses, and perhaps as small as the constituent parts of water.* The earth, the water, and the air may, for anything I know, be full of such organized atoms. They may be no more liable to hurt or injury, than the con- stituent elementary parts of water or air. They may serve the purposes of common matter until they are brought into that situation which nature has provided for their unfolding themselves. When brought into their proper matrix or womb, perhaps after some previous preparations, they are commonly surrounded with some fluid matter, in which they unfold and stretch themselves out to a length and breadth perhaps some thousand times greater than they had when folded up in the atom. They would now be visible to the naked eye, were it not that their limbs and vessels are so slender that they cannot be distin- guished from the fluid in which they float. All is equally transparent, and therefore neither figure nor colour can be discerned, although the object has a considerable bulk. The foetus now has a fluid circulating in its vessels ; all the animal functions go on ; it is nourished and grows ; and some parts, first the heart, then the head, then the * This o- inion is sim lar to that ol M. Bonnet. Sec his " Considi rations sur les Corps Organizes," and his " Contemplation de la Nature." J ord Woomiou rlee. — Rcid's opinion has comparatively little resemblance to the involution theory of Bonnet : it bears, however, a strong analogy to the Pansper- mia of the Ionic philosophers, more especially as I medified by some of the recent physiological specu- latists of Germany This conjecture is curious, as a solitary escapade of our cautious philosopher iu the region of imagination.— H, 54 CORRESPONDENCE OF DR REID. opine, by getting some colour, become visible. It is to be observed, that, from the time that the heart first appears in the pellucid liquor, until the time of birth, the animal grows gradually and insensibly, as it does after birth. But, before it is visible, it must have increased in size many thousand times in a few days. This does not look like growth by nourishment, but like a sudden unfolding of parts, which before were wrapped up in a small atom. I go along with your Lordship cordially, till you come to the first formation of an organized body. But there I hesitate. "May there," say you, " not be particles of a certain kind endowed with a power to form in conjunction an organized body V Would your Lordship allow that certain letters might be endowed with the power of forming themselves into an " Iliad" or '' ^Eneid," or even into a sensible discourse in prose ?* I confess our faculties carry us but a very little way in determining what is possible and what is impossible, and therefore we ought to be modest. But I cannot help thinking that such a work as the " Iliad," aud much more an animal or vegetable body, must have been made by express design and counsel employed for that end. And an author whom I very much respect has taught me, " That we form this conclusion, not by any process of reasoning, but by mere perception and feel- ing."^ And I think that conclusions formed in this manner, are of all others most to be trusted. It seems to me as easy to con- trive a machine that should compose a variety of epic poems and tragedies, as to contrive laws of motion, by which unthink- ing particles of matter should coalesce into a variety of organized bodies. " But," says your Lordship, " certainly the Almighty has made none of his works so imperfect as to stand in need of perpe- tual miracles." Can we, my Lord, shew, by any good reason, that the Almighty finished his work at a stroke, and has con- tinued ever since an unactive spectator ? Can we prove that this method is the best ; or that it is possible that the universe should be well governed in this way ? I fear we cannot. And, if his continued operation be neces- sary or proper, it is no miracle, while it is uniform, and according to fixed laws. Though we should suppose the gravitation of matter to be the immediate operation of the Deity, it would be no miracle, while it is constant and uniform ; but if in that case it should cease for a moment, only by his * This illustration is borrowed from Cicero. <" De .•Jatura Deoium." 1. li c. 37.)— H + Lord Karnes himself. " Fssays on Morality," ac; t> Chapter < l On the Mea of Power." withholding his hand, this would be a mi- racle. That an animal or vegetable body is a work of art, and requires a skilful workman, I think we may conclude, without going beyond our sphere. But when we would determine how it is formed, we have no data; and our most rational conjectures are only reveries, and probably wide of the mark. We travel back to the first origin of things on the wings of fancy. We would discover Nature in puris naturalibus, and trace her first operations and gradual pro- gress. But, alas ! we soon find ourselves unequal to the task : and perhaps this is an entertainment reserved for us in a future state. As to what you say about earth or soil ; there seems, indeed, to be a repulsion of the parts, when it is enriched by the air, or by manure. And, in consequence of this, it swells and occupies more space. But, I conceive, it gets an additional quantity of matter, from the moisture and air which it imbibes, and thereby increases both in bulk and weight. I have been told that a dung- hill made up of earth, dung, and lime, trenched over two or three times, at proper intervals, and then led out, will be found to make more cart-loads than it received : and I believe this to be true. If the earth taken out of a pit does not fill it again, I am apt to think there must have been va- cuities in the earth at first, perhaps made by the roots of plants that have decayed, by moles, insects, or other causes. — I am, my Lord, <\e. Tho. Reid. ON THE LAWS OF MOTION. NEWTON S AXIOMS AND DEFINITIONS. Glasgow College, Mag 19, 1780. My Lord, — In order to understand the preliminary part of Newton's Prmcipia., it is necessary to attend to his general design, both in his axioms and definitions. First, As to his axioms : he sets down the three laws of motion as axioms. But he does not mean by this, that they are to be held as self-evident truths ; nor does he in- tend to prove them in what he says upon them. They are incapable of demonstra- tion, being matters of fact, which universally obtain in the material world, and which had before been observed by philosophers, and verified by thousands of experiments by Galileo, by Wren, Wallis, Huygens, and Mariotte, to whom he refers for the proof of them. Therefore, that he might not aclumagcre,he lays them down as established truths, saying some things upon them by LETTERS TO LORD KAMES. way of illustration, and deducing some gene- ral corollaries from them. That this was his view, he expressly says in the scholium following the axioms : Jlacteniis principia tradidi, a Mathematics recepta, et multiplied enpperientia confirmata, $c. The very same method he follows in his optics, laying down as axioms what had before been discovered in that science. The axioms, or established principles in the Principia, are three : — \u, Every body perseveres in its present state, whether of motion or rest, until it is made to change that state by some force impressed upon it. 2d, The change of motion produced is al- ways proportional to the force impressed, and in the direction of that force. 3-/, All action of bodies upon each other is mutual or reciprocal, and in contrary directions ; that is, if the body A produces any motion or change of motion in B ; by the reaction of B, an equal change of motion, but in a contrary direction, will be produced in A. This holds in all action of bodies on .each other, whether by a stroke, by pressure, by attraction, or by repulsion. Perhaps, you will say these principles ought not to be taken for granted, but to lie proved. True, my Lord, they ought to be proved by a very copious induction of experiments ; and, if they are not proved, the whole system of the Principia falls to the ground ; for it is all built upon them. But Sir Isaac thought they were already proved, and refers you to the authors by whom. He never intended to prove them, but to build upon them, as mathematicians do upon the Elements of Euclid. Secondly, As to the definitions. They are intended to give accuracy and precision to the terms he uses, in reasoning from, the laws of motion. The definitions are accom- modated to the laws of motion, and fitted so as to express with precision all reasoning grounded upon the laws of motion. And, for this reason, even the definitions will appear obscure, if one has not a distinct conception of the laws of motion always be- fore his eye. Taking for granted the laws of motion, therefore, he gives the.name of vis insita, or vis inertite, to that property of bodies, whereby, according to the first and second laws of motion, they persevere in their state, and resist any change, either from rest to motion, or from motion to rest, or from one degree or direction of motion to another. This vis insita is exercised in every case wherein one body is made to change its state by the action of another body ; and the exertion of it may, in different respects, be called both resistance and impetus. The reluctance which the body A has to change its state, which can be overcome only by a force proportioned to that reluct- ance, is resistance. The reaction of the body A upon B, which, according to tl e third law of motion, is equal to the action 01 B upon A, and in a contrary direction, is impetus. Thus, in every change made in the state of one body by another, there is mutual resistance and mutual impetus. The one never exists without the other. A body at rest not only resists, but gives an impetus to the body that strikes it. And a body in motion coming against a body at rest, not only gives an impetus to the body that was at rest, but resists that change of its own motion which is produced by the stroke. Each gives an impetus to the other, and exerts a resistance to the impetus it receives from the other. This is the notion which Newton affixes to the words — impetus and resistance ; and, I think, it corresponds perfectly with the third law of motion, but may appear dark if that is not kept in view. But, because this notion of resistance and impetus differs somewhat from the vulgar application of those words, in order to point out the difference, he contrasts it with the vulgar meaning in the words which your Lordship quotes : — Valgus resistentiam quiescentibus et impel um mm-entibnstribuiU sed motus et quirs, ut vulgo concipiuntur, respectu solo distingunntur, neque semper verequiescunt qucevulgo tanquam quiescenlia spectantur. He considers both resistance and impetus as belonging to every body, in every case in which it is made to change its state, whether from rest to motion, or from motion to rest. It resists the change of its own state, and, by its reaction, gives an impetus to the body that acts upon it. The vulgar, having no notion, or no distinct notion, of this reaction established by the third law of motion, suit their language to their conceptions. He suits his to the laws of motion. A post, you say, resists, but has no im- petus. This is true in the vulgar sense of the word. But, in order to shew you that his sense differs somewhat from the vulgar, he would say, that the post has impetus in his seuse. And by this he means only, that the post stops, or changes the motion of the body that strikes it ; and, in producing this change, exerts a force equal to that with which it was struck, but in a contrary direction. This is a necessary consequence of the third law of motion. The vulgar both speak and judge of motion and rest in a body, by its situation with respect to some other body, which, perhaps, from prejudice, they conceive to be at rest. This makes Newton say, " That motion and rest, as commonly conceived, are distinguished by t elation ; nor are those bodies always really 3(i CORRESPONDENCE OF DR REIO. at rest wliicli are commonly conceived to be at rest-" Rest, when we speak of bodies, is opposed, not to self-motion only, but to all change of place. Absolute, or real rest, is opposed to real motion ; and relative rest—that is, rest with relation to such a body that is supposed at rest, is opposed to relative motion with respect to the same body. But a body may be relatively at rest, and, at the same time, really in motion. Thus, a house rests upon its foundation for ages ; but this rest is relative with respect to the earth. For it has gone round the earth's axis every day, and round the sun every year. The distinction your Lordship makes be- tween moving and being moved, belongs not to physics, but to metaphysics. In physics, you may use the active or the passive verb as you like best. The reason is, that in physics we seek not the efficient causes of phenomena, but only the rules or laws by which they are regulated. We know, that a body once put in motion, continues to move, or, if you please, to be moved, until some force is applied to stop or retard it. But, whether this phenomenon is produced by some real activity in the body itself, or by the efficiency of some external cause ; or whether it requires no efficiency at all to continue in the state into which it is put, is, perhaps, difficult to determine; and is a question that belongs not to physics, but to metaphysics. Some divines and philosophers have maintained, that- the preservation of a created being in existence, is a, continued act of creation ; and that annihilation is nothing but the suspending that exertion of the Creator by which the being was upheld in existence. Analogous to this, I think, is the opinion, that the continuance of motion in a bodv requires a continued exertion of that active force which put it into the state of motion. I am rather inclined to the contrary of both these opinions, and disposed to think that continuance of existence, and continuance of motion in a body, requires no active cause ; and that it is only a change of state, and not a continuance of the present state, that requires active power. But, I suspect, both questions are rather beyond the reach of the human faculties. However, they belong not to the province of physics, but to that of metaphysics. I wish I may be intelligible, and that T do not oppress your Lordship with the gar- rulity of old age. I find myself, indeed, growing old, and have no right to plead ex- emption from the infirniit'es of that stage of life. For that reason, I have made choice of an assistant in my office. Yesterday, the college, at my desire, made choice of Mr Archibald Arthur, preacher, to bemvassist- ant and successor.* I think I have done good service to the college by this, and pro- cured some leisure to myself, though with a reduction of my finances. May your Lord- ship live long and happy. — Yours, Tho. Reid. VI. ON CONJECTURES AND HYPOTHESES IN PHI- LOSOPHY. — CAUSE WHAT IN RELATION TO PHYSICS. — DIFFERENT PROVINCES OP PHYSICAL AND OF METAPHYSICAL SCIENCE. \6th December 1780. My Lord, — 1. I am now to answer the letter you honoured me with of 7th No- vember. And, first, I disclaim what you seem to impute to me — to wit, " the valuing myself upon my ignorance of the cause of gravity." To confess ignorance when one is conscious of it, I take to be a sign, not of pride, but of humility, and of that can- dour which becomes a philosopher ; and so I meant it. 2. Your Lordship thinks, " That never to trust to hypotheses and conjectures about the works of God, and being persuaded that they are more like to be false than true, is a discouraging doctrine, and damps the spirit of inquiry," &c. Now, my Lord, I have, ever since I was acquainted with Bacon and Newton, thought that this doc- trine is the very key to natural philosophy, and the touchstone by which everything that is legitimate and solid in that science, is to be distinguished from what is spurious and hollow ; and I cau hardly think, that we can differ in so capital a point, if we understood each other's meaning. 3. I would discourage no man from con- jecturing, only I wish him not to take his conjectures for knowledge, or to expect that others should do so. Conjecturing may be a useful step even in natural philosophy. Thus, attending to such a phenomenon, I conjecture that it may be owing to such a cause. This may lead me to make the ex- periments or observations, proper for dis- covering whether that is really the cause or not : and if I can discover, either that it is or is not, my knowledge is improved; and my conjecture was a step to that im- * Mr Arthur, a man of learning, abilities, atid worth, filled the Chair of Moral Philosophy in the University of Glasgow for fifteen ye.irs, wilh a repu- tation which did not disappoint the hopes of his respectai.le prrdece*sor. A volume of* Discourses on Theological and l.ilerarv Subjects," which give a very favourable idea of his Ulents, the justness of his tasic, and the rectiiude of his moral and religious principles, has been published, since his death, by I'lofessor Richardson of the same college — a gentle- man distinguished in the literarv world, and who hat done honour to the memory ol his friend, by an inter- esting sketrh of his life and character, .-unjoined to these discourses — Loan Wooimonsl UU-. LETTERS TO LORD KAMES. 57 provement. But, while I rest in my con- jecture, my judgment remains in suspense, and all I can say is, it may be so, and it may be otherwise. 4. A cause that is conjectured ought to be such, that, if it really does exist, it will produce the effect. If it have not this quality, it hardly deserves the name of a conjecture. Supposing it to have this quality, the question remains — Whether does it exist or not ? And this, being a question of fact, is to be tried by positive evidence. Thus, Des Cartes conjectured, that the planets are carried round the sun in a vortex of subtile matter. The cause here assigned is si.fficient to produce the effect. It may, therefore, be entitled to the name of a conjecture. But where is the evidence of the existence of such a vor- tex ? If there be no evidence for it, even though there were none against it, it is a conjecture only, and ought to have no admittance into chaste natural philosophy. 5. All investigation of what we call the causes of natural phenomena may be reduced to this syllogism — If such a cause exists, it will produce such a phenomenon : but that cause does exist : Therefore, &c. The first proposition is merely hypothetical. And a man in his closet, without consulting nature, may make a thousand such propositions, and connect them into a system ; but this is only a system of hypotheses, conjectures, or theories ; and there cannot be one con- clusion in natural philosophy drawn from it, until he consults nature, and discovers whether the causes he has conjectured do really exist. As far as he can shew that they do, he makes a real progress in the knowledge of nature, and not a step further. I hope in all this your Lordship will agree with me. But it remains (o be considered how the second proposition of the syllogism is to be proved — to wit, that such a cause does really exist. Will nothing satisfy here but demonstration ? 6. I am so far from thinking so, my Lord, that I am persuaded we never can have demonstration in this case. All that we know of til e material world, m ust be grounded on the testimony of our senses. Our senses testify particular facts only : from these we collect, by induction, general facts, which we call laws of nature, or natural causes. Thus, ascending by a just and cautious in- duction, from what is less to what is more general, we discover, as far as we are able, natural causes, or laws of nature. This is the analytical part of natural philosophy. The synthetical part takes for granted, as principles, the causes discovered by induc- tion, and from these explaius or accounts for the phenomena which result from them. This analysis and synthesis make up. the whole theory of natural philosophy. The practical part consists in applying the laws of nature to produce effects useful in life. 7. From this view of natural philosophy, which I have learned from Newton, your Lordship will perceive that no man who understands it will pretend to demon- strate any of its principles. Nay, the most certain and best established of them may, for anything we know, admit of exceptions. For instance, there is no principle in natu- ral philosophy better established than the universal gravitation of matter. But, can this be demonstrated ? By no means. What is the evidence of it, then ? It is collected by induction, partly from our daily experience, and from the experience of all nations, in all ages, in all places of earth, sea, and air, which we can reach ; and partly from the observations and expe- riments of philosophers, which shew that even air and smoke, and every body upon which experiments have been made, gravi- tate precisely in proportion to the quantity of matter ; that the sea and earth gravitate towards the moon, and the moon towards them ; that the planets and comets gravi- tate towards the sun, and towards one another, and the sun towards them. This is the sum of evidence ; and it is as differ- ent from demonstration, on the one hand, as from conjecture on the other. It is the same kind of evidence which we have, that fire will burn and water drown, that bread will nourish and arsenic poison, which, I think, would not properly be called conjecture. 8. It is proper here to explain what is meant by the cause of a phenomenon, when that word is used in natural philosophy. The word cause is so ambiguous, that I fear many mistake its meaning, and take it to mean the efficient cause, which I think it never does in this science. 9. By the cause of a phenomenon, nothing is meant but the law of nature, of which that phenomenon is an instance, or a neces- sary consequence- The cause of a body's falling to the ground is its gravity. But gravity is not an efficient cause, but a gene- ral law, that obtains in nature, of which law the fall of this body is a particular in- stance. The cause why a body projected moves in a parabola, is, that this motion is the necessary consequence of the projectile force and gravity united. But these are not efficient causes ; they are only laws of nature. In natural philosophy, therefore, we seek only the general laws, according to which nature works, and these we call the causes of what is done according to them. But such laws cannot be the efficient cause of anything. They are only the rule accord- ing to which the efficient cause operates. 10. A natural philosopher may search after the cause of a law of nature ; but this means r.o more than searching for a 58 CORRESPONDENCE OF DR REID. more general law, which includes that par- ticular law, and perhaps many others under it. This was all that Newton aimed at by his ether. He thought it possible, that, if there was such an ether, the gravitation of bodies, the reflection and refraction of the rays of light, and many other laws of nature, might be the necessary consequences of the elasticity and repelling force of the ether. But, supposing this ether to exist, its elas- ticity and repelling force must be considered as a law of nature ; and the efficient cause of this elasticity would still have been latent 11. Efficient causes, properly so called, are not within the sphere of natural philo- sophy. Its business is, from particular facts in the material world, to collect, by just induction, the laws that are general, and from these the more general, as far as we can go. And when this is done, natural philosophy has no more to do. It exhibits to our view the grand machine of the mate- rial world, analysed, as it were, and taken to pieces, with the connexions and depend- encies of its several parts, and the laws of its several movements. It belongs to another branch of philosophy to consider whether this machine is the work of chance or of design, and whether of good or of bad design ; whether there is not an intelligent first Mover who contrived the whole, and gives motion to the whole, according to the laws which the natural philosopher has dis- covered, or, perhaps, according to laws still more general, of which we can only discover some branches; and whether he does these things by his own hand, so to speak, or employs subordinate efficient causes to execute his purposes. These are very noble and important inquiries, but they do not belong to natural philosophy ; nor can we proceed in them in the way of ex- periment and induction, the only instru- ments the natural philosopher uses in his researches. 12. "Whether you call this branch of philosophy Natural Theology or Meta- physics, I care not ; but I think it ought not to be confounded with Natural Philo- sophy; and neither of them with Mathe- matics. Let the mathematician demon- strate the relation of abstract quantity ; the natural philosopher investigate the laws of the material system by induction ; and the metaphysician, the final causes, and the efficient causes of what we see and what natural philosophy discovers in the world we live in. 13. As to final causes, they stare us in the face wherever we cast our eyes. I can no more doubt whether the eye was made for the purpose of seeing, and the ear of hearing, than I can doubt of a mathema- tical axiom ; yet the evidence is neither mathematical demonstration, nor is it in- duction. In a word, final causes, good final causes, are seen plainly everywhere : in the heavens and in the earth ; in the constitu- tion of every animal, and in our own consti- tution of body and of mind ; and they are most worthy of observation, and have a charm in them that delights the soul. 14. As to Efficient Causes, I am afraid our faculties carry us but a very little way, and almost only to general conclusions. I hold it to be self-evident, that every pro- duction, and every change in nature, must have an efficient cause that has powei to produce the effect ; and that an effect which has the most manifest marks of in- telligence, wisdom, and goodness, must have an intelligent, wise, and good efficient cause. From these, and some such self-evident truths, we may discover the principles of natural theology, and that the Deity is the first efficient cause of all nature. But how far he operates in nature immediately, or how far by the ministry of subordinate effi- cient causes, to which he has given power adequate to the task committed to them, I am afraid our reason is not able to discover, and we can do little else than conjecture. We are led by nature to believe ourselves to be the efficient causes of our own volun- tary actions ; and, from analogy, we judge the same of other intelligent beings. But with regard to the works of nature, I can- not recollect a single instance wherein I can say, with any degree of assurance, that such a thing is the efficient cause of such a phe- nomenon of nature. 15. Malebranche, and many of the Car- tesians, ascribed all to the immediate oper- ation of the Deity, except the determinations of the will of free agents. Leibnitz, and all his followers, maintain, that God finished his work at the creation, having endowed every creature and every individual particle of matter, with such internal powers as necessarily produce all its actions, motions, and changes, to the end of time- Others have held, that various intelligent beings, appointed by the Deity to their several departments, are the efficient causes of the various operations of nature. Others, that there are beings endowed with power with- out intelligence, which are the efficient causes in nature's operations ; and they have given them the name of Plastic Fowers, or Plastic Natures. A late author of your Lordship's acquaintance,* has given it as ancient metaphysics, That every body in the universe is compounded of two sub- stances united— to wit, an immaterial mind or soul, which, in the inanimate creation, has the power of motion without thought ; and of inert matter as the other part. The celebrated Dr Priestley maintains, that • Lord Monboddo H. LETTERS TO LORD KAMES. 59 matter, properly organized, has not only the power of motion, but of thought and intel- ligence ; and that a man is only a piece of matter properly organized. 16. Of all these systems about the effi- cient causes of the phenomena of nature, there is not one that, in my opinion, can be either proved or refuted from the principles of natural philosophy. They belong to metaphysics, and affect not natural philo- sophy, whether they be true or false. Some of them, I think, may be refuted upon meta- physical principles ; but, as to the others, I can neither see such evidence for them or against them as determines my belief. They seem to me to be conjectures only about matters where we have not evidence ; and, therefore, I must confess my ignor- ance. 17. As to the point which gave occasion to this long detail, Whether there is reason to think that matter gravitates by an in- herent power, and is the efficient cause of its own gravitation, I say, first, This is a metaphysical question, which concerns not natural philosophy, and can neither be proved nor refuted by auy principle in that science. Natural philosophy informs us, that matter gravitates according to a certain law ; and it says no more. Whether mat- ter be active or passive in gravitation, can- not be determined by any experiment I can think of. If it should be said that we ought to conclude it to Tse active, because we per- ceive no external cause of its gravitation, this argument, I fear, will go too far. Be- sides it is very weak, amounting only to this : I do not perceive such a thing, there- f ire it does not exist. 18. I never could see good reason to believe that matter has any active power at all. And, indeed, if it were evident that it has one,! think there could be no good reason assigned for not allowing it others. Your Lordship speaks of the power of resisting motion, and some others, as acknowledged active powers inherent in matter. As to the resistance to motion, and the continu- ance in motion, I never could satisfy my- self whether these are not the necessary consequences of matter being inactive. If they imply activity, that may lie in some other cause. 1!). I am not able to form any distinct conception of active power but such as I find in myself. I can only exert my active power by will, which supposes thought. It seems to me, that, if I was not conscious of activity in myself, I could never, from things I see about me, have had the conception or idea of active power. I see a succession of changes, but I fee not the power, that is, the efficient cause of them ; but, having got the notion of active power, from the con- sciousness of my own activity, and finding it a first principle, that every production requires active power, I can reason about an active power of that kind I am acquainted with — that is, such as supposes thought and choice, and is exerted by will. But, if there is anything in an unthinking inanimate being that can be called active power, I know not what it is, and cannot reason about it. 20. If you conceive that the activity of matter is directed . by thought and will in matter, every particle of matter must know the situation and distance of every other particle within the planetary system ; but this, I am apt to think, is not your Lord- ship's opinion. 21. I must therefore conclude, that this active power is guided in all its operations by some intelligent Being, who knows both the law of gravitation, and the distance and situation of every particle of matter with regard to every other particle, in all the changes that happen in the material world. I can only conceive two ways in which this particle .pf matter can be guided, in all the exertions of its active power, by an intelli- gent Being. Either it was formed, in its creation, upon a foreknowledge of all the situations it shall ever be in with respect to other particles, and had such an internal structure given it, as necessarily produces, in succession, all the motions, and tend- encies to motion, it shall ever exert. This would make every particle of matter a ma- chine or automaton, and every particle of a different structure from every other particle in the universe. This is indeed the opinion of Leibnitz ; but I am not prejudiced against it upon that account ; I only wished to know whether your Lordship adopted it or not. Another way, and the only other way, in which I can conceive the active power of a particle of matter, guided by an intelligent Being, is by a continual influence exerted according to its situation and the situation of other particles. In this case, the particle would be guided as a horse is by his rider ; and I think it would be improper to ascribe to it the power of gravitation. It has only the power of obeying its guide. Whether your Lordship chooses the first or the last in this alternative, I should be glad to know ; or whether you can think of a third way better than either. 22. I will not add to the length of so immoderately long a letter by criticising upon the passages you quote from Newton. I have a great regard for his j udgment ; but where he differs from me, I think him wrong. The idea of natural philosophy I have given in this letter, I think I had from him. If in scholia and queries he gives a range to his thoughts, and sometimes enters the regions of natural theology and metaphysics, this I think is very allowab'c, and is not to 60 CORRESPONDENCE OF DR REID. be considered a part of his physics, which are contained in his propositions and corol- laries. Even his queries and conjectures are valuable ; but I think he never intended that they should be taken for granted, but made the subject of inquiry. Tho. Reid. VII. LAWS OF MOTION PRESSURE OF FLUIDS. January 25, 1781. My Lord, — To what cause is it owing that I differ so much from your Lordship in Fhysics, when we differ so little in Meta- physics ? I am at a loss to account for this phenomenon. Whether is it owing to our having different conceptions to the same words ? — or, as I rather think it is, to your being dissatisfied with the three gene- ral laws of motion ? Without them I know not indeed how to reason in physics. Ar- chimedes reasoned from them both in me- chanics and hydrostatics. Galileo, Huy- gens, Wren, Wallis, Mariotte, and many others, reasoned from them, without ob- serving that they did so. I have not indeed any scruples about the principles of hydrostatics. They seem to me to be the necessary consequences of the definition of a fluid, the three laws of motion, and the law of gravitation ; and, therefore, I cannot assent to your Lordship's reason- ing, either about the pressure of fluids, or about the suspension of the mercury in the barometer. As to the first, the experiments which shew that fluids do, in fact, press undequaque, are so numerous, and so well known to your Lordship, that I apprehend it is not the fact you question, but the cause. You think that gravity is not the cause. Why ? Be- cause gravity gives to every part of the fluid a tendency downwards only ; and what is true of every part, is true of the whole : therefore, the whole has no other tendency but downward. This argument is specious, but there is a fallacy in it. If the parts did not act upon one another, and counteract one another, the argument would be good ; but the parts are so connected, that one cannot go down but auother must go up, and, therefore, that very gravity which presses down one part presses up another : so that every part is pressed down by its own gravity, and pressed up, at the same time, by the gravity of other parts ; and the contrary pressures being equal, it re- mains at rest. This may be illustrated by a balance equilibrating by equal weights in both scales. 1 say each arm of the balance is equally pressed upwards and downwards at the same time, and from that cause is at rest ; although the tendency of the weights, in each of the scales, is downwards only. I prove it a pos- teriori ; because the arm of a balance being moveable by the least force, if it was pressed in oue direction only, it would move in that direction : but it does not move. I prove it a priori ; because the necessary effect of pressing one arm down, is the pressing the other up with the same force : therefore, each arm is pressed down by the weight in its own scale, and equally pressed up by the weight in the other scale ; and, being pressed with equal force in contrary directions, it remains at rest. Your Lordship will easily apply this reasoning to a fluid, every part of which is as moveable as the balance is about its fulcrum ; and no one part can move, but an equal part must be moved in a contrary direction. And I think it is impossible we should differ in this, but in words. Next, as to the barometer. You say the mercury is kept up by the expansive power of the air : but you say further, that it is not kept up by the weight of the air. I agree to the first, but not to the last. The expansive power of the air is owing to its being compressed ; and it is compressed by the weight of the incumbent atmosphere. Its expansive force is exactly equal to the force that presses and condenses it ; and that force is the weight of the air above it, to the top of the atmosphere — so that the ex- pansive force of the air is the causa proximn, the weight of the atmosphere the causa remota of the suspension of the mercury. Your Lordship knows the maxim, Causa causes est causa causati. The barometer, therefore, while it measures the expansive force of the air which presses upon the lower end of the tube, at the same time measures the weight of the atmosphere, which is the cause of that expansive force, and exactly equal to it. If the air was not pressed by the incumbent weight, it would expand in boundless space, until it had no more expansive force. As to the observation in the postscript, it is true, that the gravity of the air, while it rests upon an unyielding bottom, will give no motion to it ; but the mercury in the lower end of the tube yields to the pressure of the air upon it, until the weight of the mercury is balanced by the prassure of the air. What your Lordship is pleased to call the Opas Mar/man, goes on, but more slowly than I wish — I am, most respectfully, my Lord, yours, Tho. Reid. LETTERS TO LORD KAMES. 61 VIII. ON THE ACCELERATED MOTION OF FALLING BODIES. Glasgow College, Nov. 11, 1782. My Lord, — My hope that your Lordship is in no worse state of health than when I left you, and that the rest of the good family are well, is confirmed by your continuing your favourite speculations. I promised to call upon you in the morning before I came away. I sent in Samuel to see if you was awake : he reported that you was sleeping sound ; and I could not find it in my heart to disturb your repose. When we say, that, in falling bodies, the space gone through is as the square of the velocity, it must be carefully observed that the velocity meant in this proposition, is the last velocity, which the body acquires only the last moment of its fall : but the space meant is the whole space gone through, from the beginning of its fall to the end. As this is the meaning of the proposition, your Lordship will easily perceive, that the velocity of the last moment must indeed correspond to the space gone through in that moment, but cannot correspond to the space gone through in any preceding moment, with a less velocity ; and, consequently, can- not correspond to the whole space gone through in the last and all preceding mo- ments taken together. You say very justly, that, whether the motion be equable or accelerated, the space gone through in any instant of time corresponds to the velocity in that instant. But it does not follow from this, that, in accelerated motion, the space gone through in many succeeding instants will correspond to the velocity of the last instant. If any writer in physics has pretended to demonstrate mathematically this proposi- tion — that a body falling by gravity in vacuo, goes through a space which is as the square of its last velocity ; he must be one who writes without distinct conceptions, of which kind we have not a few. The proposition is not mathematical, but physical. It admits not of demonstration, as your Lordship justly observes, but of proof by experiment, or reasoning grounded on experiment. There is, however, a ma- thematical proposition, which possibly an inaccurate writer might confound with the last mentioned. It is this — that a body uniformly accelerated from a state of rest, will go through a space which is as the square of the last velocity. ' This is an ab- stract proposition, and has been mathema- tically demonstrated ; and it may be made a step in the proof of the physical proposi- tion. But the proof must be completed by shewing, that, in fact, bodies descending by gravitation are uniformly accelerated. This is sometimes shewn by a machine invented by S'Gravesande, to measure the velocities of falling bodies ; sometimes it is proved by the experiments upon pendulums ; and sometimes we deduce it by reasoning from the second law of motion, which we think is grounded on universal experience. So that the proof of the physical proposition always rests ultimately upon experience, and not solely upon mathematical demonstra- tion. — I am, my Lord, respectfully yours, Tho. Reid. IX. EXTRACT OF A LETTER TO MRS DRUMMOND, AFTER THE DEATH OF HER HUSBAND, LORD KAMES, IN 1782. I accept, dear madam, the present you sent me,*" as a testimony of your regard, and as a precious relic of a man whose talents I admired and whose virtues I honoured ; a man who honoured me with a share of his conversation, and of his cor- respondence, which is my pride, and which gave < me the best opportunity of knowing his real worth. I have lost in him one of the greatest comforts of my life; but his remembrance will always be dear to me, and demand my best wishes and prayers for those whom he has left behind him. When time has abated your just grief for the loss of such a husband, the recol- lection of his eminent talents, and of his public and domestic virtues, will pour balm into the wound. Friends are not lost who leave such a character behind them, and such an example to those who come after them. A gold snuff boy. 62 CORRESPONDENCE OF DR REID. C— LETTERS TO DR JAMES GREGORY. I. Glasqou Crl/cge, April 7, 1783. Dear Smj— By favour of Mr Patrick Wilson, our Assistant Frofessor of Astro- nomy, I send you two more numbers of my lucubrations.* I am not sure when I can send more, as I am not sure whether my scribe may soon leave the College. I shall be much obliged to you if you will continue to favour me with your observa- tions, though I have put off examining those you have sent until the MSS. be returned, which I expect about the end of this month, along with Dug. Stewart's observations. I have also sent the Genealogy of the Gre- gories, which your brother left with me : I suspected that it was more particular than the copy I had, but I find they agree per- fectly. You will please deliver it to him, with my compliments. The few days he was here he payed his respects to all the Pro- fessors and all his acquaintance, and they are all very much pleased with his appear- ance. If it please God to spare his life, I hope he will do honour to his Alma Mater. and to his friends. -f* I know not upon what authority the Edinburgh and London news-writers have given contradictory accounts of Dr Hun- ter's settlements.^: There is nothing cer- tainly known here. I know that, six or seven years ago, he made a settlement very favourable to this College. But whether this is altered, or in what respect, I believe nobody here knows. But we shall probably know soon. He was surely a man that did great honour to his country, and I doubt not but his publick spirit, which I take to have been great, will have disposed him to leave his books, medals, and other literary furniture — which he had collected at vast expense, and with great industry — in such a way as that it may be useful to the pub- lick. I beg you to make my best respects to Mrs Gregory, and to all your family ; and I am, dear Sir, Your most obedient Servant, Tho. Ekid. * His " Essays on 'he Intellectual Powers " — H. t This was the Rev. William Gregory, A. M. of Ralliol College, Oxford, afterwards Hector of St Mary's, Bentham, and one of the Preachers of Can- terbury Cathedral. He had studied at Glasgow pre- viously to ei tcring at Oxford. — H„ X The celebrated Dr Win Hunter. He bequeathed his anatomical preparations, library, and collection of medals, to the University of Glasgow, and a sum of money for the ereclion of a museum.— H. II. Glasgow College, June 8, 1783. Dear Sir, I cannot get more copied of my papers till next winter, and indeed have not much more ready. This parcel goes to page 658. I believe what you have got before may be one-half or more of all I intend. The materials of what is not yet ready for the copyer are partly discourses read in our Literary So- ciety, partly notes of my Lectures. Your judgment of what you have seen flatters me very much, and adds greatly to my own opinion of it, though authors sel- dom are deficient in a good opinion of their own works. I am at a loss to express my obligations to you for the pains you have taken, and pro- pose to take again upon it. I have carefully laid up the observations you sent me, to be considered when the copy they refer to is returned, and I hope for the continuation of them. The analogy between memory and prescience is, I believe, a notion of my own. But I shall be open to conviction on this and every thing else we may differ about. I have often thought of what you propose — to give the History of the Ideal System ; and what I have to say against it, by itself, and I am far from being positive that it stands in the most proper place. Perhaps it will be easier to judge of this when the work is concluded. I have endeavoured to put it in separate chapters, whose titles may direct those who have no taste for it to pass over them. But I hope to have your opi- nion upon this point at more length when we meet- I observe that Boyle and others, who, at the Reformation of Natural Philo- sophy, gave new light, found it necessary to contrast their discoveries with the Aristo- telian notions which then prevailed. We could now wish their works purged of the controversial part ; but, perhaps, it was pro- per and necessary at the time they wrote, when men's minds were full of the old sys- tems, and prepossessed in its favour. What I take to be the genuine philosophy of the human mind, is in so low a state, and has so many enemies, that, I apprehend those who would make any improvement in it must, for some time at least, build with one hand, and hold a weapon with the other. I shall be very glad to see you heue, and will take it as a favour if you acquaint me when you have fixed your time, that I may be sure to be at home. I beg you will LETTERS TO DB JAMES GREGORY 63 make my best compliments to Mrs Gregory, whom I should be happy to see along with you in good health, and to Mr D. Gordon, if he is still with you, and to all your fa- mily ; and am, dear sir, Yours most affectionately, Tho. Reid. III. March 14, 1784. Dear Sir, — I send you now the remainder of what I propose to print with respect to the Intellectual Powers of the Mind. It may, perhaps, be a year before what relates to the Active Powers be ready, and, there- fore, I think the former might be published by itself, as it is very uncertain whether I shall live to publish the latter. I have enclosed, in the first of the three papers now sent, the contents of the whole, which you was so good as to write out as far as it was carried last year. I think the title may be, Essays on the Intellectual Powers of the Human Mind. It will easily divide into eight essays, as you will see by the contents ; but with regard to this, as well as whether the two parts may be published separately, I wish to have your advice and Mr Stuart's — (Sic.) Since you have been so good as to take a concern in it, I apprehend that the second Part — I mean what relates to the Active Powers — will not be near so large as the first. I wish to have the manuscript, with your remarks and Mr Stuart's, (sic,) about the end of April, if you can. Dr Eose at Chiswick — who, you know, has all along had a principal concern in The Monthly Review — has made me a very kind offer, that, if I please to send the MSS. to him, he will both give me his remarks, and treat with a bookseller about the sale of it. I think this is an offer that I ought not to re- fuse ; and I can have a good occasion of sending it about the beginning of the month of May, by his son, who is at this college. I long to hear how Mrs Gregory has stood this severe winter, and beg my most humble respects to her, and to the Rev. Mr Wil- liam, when you write him. I send you on the other page an anecdote respecting Sir I. Newton,* which I do not remember whether I ever happened to men- tion to you in conversation. If his descent be not clearly ascertained, (as I think it is not in the books I have seen,) might it not be worth while for the antiquarian branch of your R. Society, to inquire if they can find evidence to confirm the account which he is said to have given of himself. Sheriff Cross was very zealous about it, • See Brewster's " Life of Newton," and, ro/r.7, Reicl's letter to Mr Robison, at the end of his Cor. respondents. — H. when death put a stop to his inquiries I am, dear Sir, yours most respectfully, Tho. Reid. When I lived in Old Aberdeen, above twenty years ago, I happened to be con- versing over a pipe of tobacco, with a gen- tleman of that country, who had been lately at Edinburgh. He told me that he had been often in company with Mr Hepburn of Keith, with whom I had the honour of some acquaintance. He said that, speaking of Sir Tsaac Newton, Mr Hepburn men- tioned an anecdote, which he had from Mr James Gregory, Professor of Mathematics at Edinburgh, which was to this purpose : — Mr Gregory being at London for some time after he resigned the mathematical chair, was often with Sir I. Newton. One day Sir Isaac said to him, " Gregory, I believe you don't know that I am connected with Scotland." " Pray, how, Sir Isaac ?" said Gregory. Sir Isaac said — " He was told, that his grandfather was a gentleman of East Lothian ; that he came to London with King James at his accession to the Crown of England, and there spent his fortune, as many more did at that time, by which his son (Sir Isaac's father) was reduced to mean circumstances." To this Gregory bluntly replied — " Newton, a gentleman in East Lothian ? — I never heard of a gentleman of East Lothian of that name." Upon this Sir Isaac said, that, being very young when his father died, he had it only by tradition, and it might be a mistake ; and imme- diately turned the conversation to another subject. I confess I suspected that the gentleman who was my author had given some colour- ing to this story ; and, therefore, I never mentioned it for a good many years. After I removed to Glasgow, I came to be very intimately acquainted with Mr Cross, the Sheriff of Lanerick, and one day at his own house mentioned this story with- out naming my author, of whom I expressed some diffidence. The Sheriff immediately took it up as a matter worth being inquired into. He said he was well acquainted with Mr Hepburn of Keith, (who was then alive,) and that he would write him, to know whether he ever heard Mr Gregory say that he had such it conversation with Sir Isaac Newton. He said, he knew that Mr Keith, the ambassador, was also inti- mate with Mr Gregory, and that he would write him to the same purpose. Some time after, Mr Cross told me, -that he had answers from both the gentlemen above- mentioned, and that both remembered to have heard Mr Gregory mention the con- versation between him and Sir Isaac New- ton to the purpose above narrated ; and at the same time acknowledged that thev had 64 CORRESPONDENCE OF DR RKID. made no farther inquiry about the mat- ter. Mr Cross, however, continued in the inquiry ; and, a short time before his death, told me, that all he had learned was, that there is, or was lately, a baronet's family of the name of Newton in West-Lothian, or Mid-Lothian, (I have forgot which;) that there is a tradition in that family that Sir Isaac Newton wrote a letter to the old knight that was, (I think Sir John New- ton ' of Newton was his name,) desiring to know what children, and particularly what sons he had ; their age, and what profes- sions they intended. That the old baronet never deigned to return an answer to this letter, which his family was sorry for, as they thought Sir Isaac might have intended to do something for them. IV. Dear Sib, — Happening to have gone into the country a little way, your letter of 5th June did not reach me in time to write you before you set out upon your journey, which I wish to be attended with much happiness to the parties, and comfort to their friends. • I was so stupid at first as to misunder- stand the direction you gave me how to write you. Now I see it is plain enough, and I hope have taken it right. I send you the enclosed to Dr Rose, as you desire. I have by me our friend D. Stewart's " Discourse on the Ideas of Cause and Effect," &c. ; and I have this day sent him my remarks upon it. I am happy to find his sentiments on that subject agree so much with my own. I think it well wrote, and hope it will be very useful. Dr Rose will shew you the letter I wrote to him along with the MSS., and one from Mr Bell+ to me, which I enclosed in it : these contain all the information I have to give, and all the instructions I thought necessary. I expect an answer from one quarter, at least, before the work be cold from the press. But the only answer that shall ever have any reply from me must be one. who keeps good temper, and who observes good manners, in the first place ; and next one who, in my opinion, gives new light to the subject. I wish you happy success in your own affairs, and a safe return. If nothing hap- pens of which you wish to acquaint me sooner, I shall be glad to hear from you on your return ; being, dear sir, Most affectionately yours, Tho. Reid. Glasgow Coll 1784. • This alludes to the marriage of Dr Gregory's eldest sister to the Kev. Archibald Alison.— H. J Ihc publisher — 11. [ The letter quotr.il above by Mr Stewart, (/>. 34) " to one of Dr Jleid's most intimate friends,* 1 was addressed toDrJame.-t Gregory on the death of his first wife, and should properly here find its place. — H. ] V. ON THE MEANING OF NOTION. Glasgow College, December 31, 1784. Dear Sir, — I had the favour of yours by Mr Tower, and take the opportunity of his return to wish you many happy returns of this season. I believe you and I cannot differ about right or wrong notions, but in words. The notions we have of real existences, may with good reason be said to be right or wrong, true or false ; but I think every notion of this kind has a standard to which I believe my notion to agree ; and as that belief is true or false, so my notion of the thing is true or false. For instance, if my notion of the Devil includes horns and cloven feet, I must believe these to be attributes of the Devil, otherwise they would not be included in my notion of him. If this be- lief be wrong, I have a wrong notion of him ; and, as soon as I am convinced that this belief is wrong, I leave out these attributes in my notion of him. I may have an abstract notion of a being with horns and cloven feet, without apply- ing it to any individual — then it is a simple apprehension, and neither true nor false ; but it cannot be my notion of any indivi- dual that exists, unless I believe that being to have these attributes. I am therefore still apt to think that true and false can only with propriety be applied to notions which include some belief; but whether my re- mark on your use of the word notion be just or not, I cannot presently say : you will judge for yourself. I thought to have seen D. Stewart here about this time. When you see him, please acquaint him that I have made my remarks upon the performance he left with me. I am extremely obliged to you and him for correcting the sheets of my performance. You leave me very little to do. By the slowness of printing, I conjecture that the book cannot be published next spring, and can only be ready for the spring 1786. I desired long ago to know of Mr Bell whether he proposed to publish it in one vol. or two ; but I have not had an answer. I suspect it will be too thick for one vol. and too thin for two. Perhaps if the publication is delayed to 1786, 1 might have my Essays on the Active Powers ready, of which Mr Bell shall have the first offer; and I apprehend that, with this LETTERS TO DR JAMES GREGORY. ( ; 5 (Edition, there may be two sizeable 4tos in the whole. — I am, dear Sir, Yours most affectionately, Tho. Reid. VI. Dear Sir, — I send you enclosed what I propose as the title-page of my essays, with an epistle, which, I hope, you and Mr Stewart will please to allow me to prefix to them. Whether your name should go first, on account of your doctor's degree, or Mr Stewart's, on account of his seniority as a professor, I leave you to adjust between yourselves. * As to the title-page, you and he may alter what you think fit,t and deliver it to Mr Bell without farther communication with me, as he intends immediately to ad- vertise the book. If you find anything in the epistle that you would have altered or corrected, you may please write me; but you need not send back the copy, as I have a copy by me. I know not how to express my obliga- tions to you and Mr Stewart for the aid you have given me I am, dear Sir, your most obliged servant, Tho. Reid. May 2d, 1785, Glasgow College. You will give the epistle to the printers when it is wanted. I send with this the last part of the MS. VII. MEANINGS OP CAUSE — MOTIVE — LAW OF NATURE. June 14, 1785. Dear Sir, — I am extremely obliged to you for your friendly consultation about my health. For two days past, I have had almost nothing of my ailment, which I ascribe to some exercise I have taken, and to a comfortable warmness in the air. I resolve to try some short excursions, which I can make either on foot or in a chaise. If that do not produce the effect, I shall fall to your prescriptions, which I think very rational. I very probably may be at home when you propose to be in Glasgow. * In the MS. dedication of the " Essays on the Intellectual Powers," Dr Gregory's name 6tands before that of Mr Stewart. This order was, probably by Dr Gregory himself, reversed. There are ,also some verbal improvements in the style of the dedica- tion, as it stands printed, which, it is likely, were introduced hy Dr Gregory or Mr Stewart.— H. t The title sent was, " Essays on the Intellectual Powers of the Human Mind," or, " Essays on the Intellectual Powers of Man." The latter was pre- ferred.— H. Your speculation to demonstrate, mathe- matically, the difference between the rela- tion of motive and action, and the relation of cause and effect," is, indeed, so new to me, that Icannoteasilyforma judgment about it. I shall offer some of my thoughts on the sub- ject of those two relations. Whether they be favourable to your speculation, or unfavour- able, I cannot immediately determine. The word cause, is very ambiguous in all languages. I have wrote a chapter lately upon the causes of this ambiguity. The words power, agent, effect, have a like am- biguity ; each different meaning of the first mentioned word leading to a corresponding meaning of the three last. A reason, an end, an instrument, and even a motive, is often called a cause. You certainly exclude the last from what you call a cause. Whether you exclude all the other meanings which I think improper meanings, I am not so sure. In the strict and proper sense, I take an efficient cause to be a being who had power to produce the effect, and exerted that power for that purpose. Active power is a quality which can only be in a substance that really exists, and is endowed with that power. Power to pro- duce an effect, supposes power not to pro- duce it ; otherwise it is not power but neces- sity, which is incompatible with power taken in a strict sense- The exertion of that power, is agency, or efficiency. That every event must have a cause in this proper sense, I take to be self-evident. I should have noticed that I am not able to form a conception how power, in the strict sense, can be exerted without will ; nor can there be will without some degree of under- standing. Therefore, nothing can be an efficient cause, in the proper sense, but an intelligent being- I believe we get the first conception of power, in the proper sense, from the con- sciousness of our own exertions ; and, as all our power is exerted by will, we cannot form a conception how power can be exerted with- out will. Hence the only notion we can form of Almighty power in the Deity, is that *This refers to Dr Gregory's ingenious " Essay on the Differencebetween theRelation of Motive and Action, and that of Cause and Effect in Physics ; on physical and mathematical principles." This treatise, which was published in 1792, had been previously commu- nicated to various philosophical friends, and in par- ticular to every Necessitarian of the author's ac- quaintance, with the assurance that, if any error could be pointed out in the reasoning — which, as mathematical, could be examined with the utmost rigour — the objection should either be completely answered, or the. essay itself suppressed. Only one Necessitarian, however, allowed his objections to be published ; and these, with Dr Gregory's answers, are to be found in the appendix to the essay. Dr Heid was among the first to whom Dr Gregory com- municated this work ; and to Dr Reid, when pub- lished, the '• Philosophical and Literary Essays'* were inscribed.— H. 66 CORRESPONDENCE OF DR REID. he can do whatever he wills. A power to do what he does not will, is words without a meaning. Matter cannot he the cause of anything ; it can only be an instrument in the hands of a real cause. Thus, when a body has a cer- tain force given it by impulse, it may com- municate that force to another body, and that to a third, and so on. But, when we traoe back this motion to its origin, it must nave been given, not by matter, but by some being which had in itself the power of be- ginning motion — that is, by a proper efficient cause of motion. It cannot be said that there is a constant conjunction between a proper cause and the effect ; for, though the effect cannot be, without power to produce it, yet that power may be, without being exerted, and power which is not exerted produces no effect. You will see, by what is said above, what I take to be the strict and proper meaning of the word cause, and the related words, power, agent, fyc. In this sense we use it in reasoning concerning the being and attributes of the Deity. In this sense we ought to use it in the question about liberty and necessity, and, I think, in all metaphy- sical reasoning about causes and effects; for when, in metaphysical reasoning, we de- part from this sense, the word is so vague that there can be no clear reasoning about it. Suppose, now, that you take the word cause in this strict sense ; its relation to its effect is so self- evidently different from the relation of a motive to an action, that I am jealous of a mathematical demonstration of a truth so self-evident. Nothing is more difficult than to demonstrate what is self- evident. A cause is a being which has a real existence ; a motive has no real exist- ence, and, therefore, can have no active power. It is a thing conceived, and not a thing that exists ; and, therefore, can neither he active nor even passive. To say that a motive really acts, is as absurd as to say that a motive drinks my health, or that a motive gives me a box on the ear. In physics, the word cause has another meaning, which, though I think it an im- proper one, yet is distinct, and, therefore, may be reasoned upon. When a phenome- non is produced according to a certain law of nature, we call the law of nature the cause of that phenomenon ; and to the laws of nature we accordingly ascribe power, agency, efficiency. The whole business of physics is to discover, by observation and experi- ment, the laws of nature, and to apply them to the solution of the phenomena : this we call discovering the causes of things. But this, however common, is an improper sense of the word cause. A law of nature can no more be an agent than can a motive. It is a thing conceived, and not a thing that exists ; and, therefore, can neither act, nor be acted upon. A law of nature is a purpose or resolution of the author of nature, to act according to a cer- tain rule — either immediately by himself or by instruments that are under his direction. There must be a real agent to produce the phenomenon according to the law. A malefactor is not hanged by the law, hut according to the law, by the executioner. I suspect you use the word cause in this sense for a law of nature, according to which a phenomenon is produced. If so, it should appear distinctly that you do so. But is it not self-evident, that the rela- tion between a law of nature and the event which is produced according to it, is very different from the relation between a motive and the action to which it is a motive ? Is there any need of demonstration for this ? or does it admit of demonstration ? There is, indeed, a supposition upon which the two relations would he very similar. The supposition is, that, by a law of nature, the influence of motives upon actions is as invariable as is the effect of impulse upon matter ; but to suppose this is to suppose fatality and not to prove it. It is a question of fact, whether the in- fluence of motives be fixed bylaws of nature, so that they shall always have the same effect in the same circumstances. Upon this, indeed, the question about liberty and necessity hangs. But I have never seen any proof that there are such laws of nature, far less any proof that the strongest motive always prevails. However much our late fatalists have boasted of this principle as of a law of nature, without ever telling us what they mean by the strongest motive, I am persuaded that, whenever they shall be pleased to give us any measure of the strength of motives distinct from their pre- valence, it will appear, from experience, that the strongest motive does not always prevail. If no other test or measure of the strength of motives can be found but their prevailing, then this boasted principle will be only an identical proposition, and signify only that the strongest motive is the strong- est motive, and the motive that prevails is the motive that prevails — which proves nothing. May it not be objected to your reasoning, that you apply the three laws of motion to motives ; but motives may be subject to other laws of nature, no less invariable than the laws of motion, though not the same. Different parts of nature have different laws, it may be said; and to apply the laws of one part to another part, particularly to apply the laws of inert matter to the phe- nomena of mind, may lead into great falla- cies. I think, indeed, that your reasoning LETTERS TO DR JAMES GREGORY. 67 proves, that, between the influence of mo- tives upon a mind and the influence of impulse upon a body, there is but a very slight analogy, which fails in many in- stances. I have wearied you and myself with a long detail, I fear, little to the purpose ; but it was in my head, and so came out. I am just setting out on a jaunt to Paisley, with my wife, son-in-law, and daughter, to come home at night. Yours most affectionately, Tfio. Reid. VIII. MEANING OF CAUSE. Deak Sir, — I believe 1 have never an- swered the letter you favoured me with of Aug. 9, by Capt. Gallie. First, I obeyed your commands in attending Mrs Siddons twice, in " Douglas," and in " Venice Pre- served. " I believe I should have had much more pleasure if, on account of deafness, I had not lost much of what she said, and had been better acquainted with the plays. But I believe she is really an admirable actress, and deserves the admiration you express of her. You say, you fear we shall never agree with respect to the notion of cause and effect. I am at a loss to know wherein we differ. I think we agree in this, that a cause, in the proper and strict sense, (which, I think, we may call the metaphysical sense,) signifies a being or mind that has power and will to produce the effect. But there is another meaning of the word cause, which is so well authorized by custom, that we cannot always avoid using it, and I think we may call it the physical sense ; as when we say that heat is the cause that turns water into vapour, and cold the cause that freezes it into ice. A cause, in this sense, means only something which, by the laws of nature, the effect always follows. I think natural philosophers, when they pre- tend to shew the causes of natural phenom- ena, always use the word in this last sense ; and the vulgar in common discourse very often do the same. The reason why I take no notice of neuter verbs is, that I conceive they are used to express an event, without any signification of its having a cause or not. But I shall be very glad to see your speculations upon this subject when they are ready. I had a, letter from Dr Price lately, thanking me for a copy of the Essays I ordered to be presented to him, which he has read, and calls it a work of the first value ; commends me particularly for treat- ing his friend Dr Priestly so gently, who, he says, had been unhappily led to use me ill As you are so kind as to ask about my distemper, I think it is almost quite gone, so as to give me no uneasiness. I abstain from fruit and malt liquor, and take a little port wine, morning, noon, and night, not above two bottles in a week when alone. The more I walk, or ride, or even talk or read audibly, I am the better. When your time is fixed for coming here, I shall be glad to know it. — I am, dear Sir, Most affectionately yours, Tho. Reid. Glasgow, 23rf Sept. 1785. IX. ON CAUSE AND EFFECT— MOTIVE AND ACTION. [March 1786.] Dear Sir, — I hope your essay, along with this, will come to your hand by the carrier, and within the time you mention. It would have been sent sooner if I had not had a discourse to deliver before our Lite- rary Society last Friday. You give me most agreeable intelligence — • first, of Mrs Stewart's being so far recovered of a dangerous illness, and then of my friend William's promotion, who, I hope, will wear the robe with decency and dignity. Your essay I have read several times with attention, and I think the reasoning perfectly conclusive to prove that the rela- tion between motives and actions is totally of a different kind from that which physical causes bear to their effects. I agree with you that the hypothesis you combat in this essay is more unreasonable than that of constant conjunction. Not because it is more reasonable to conceive a constant conjunction between motives and actions than an occasional one ; but be- cause the first agrees better than the last with the hypothesis of motives being physi- cal causes of actions. Between a physical cause and its effect, the conjunction must be constant, unless in the case of a miracle, or suspension of the laws of nature. What D. Hume says of causes, in general, is very just when applied to physical causes, that a constant conjunction with the effect is essen- tial to such causes, and implied in the very conception of them. The style of this essay is more simple than that of the last, and, I think, on that account, more proper for a philosophical dissertation. I am proud of the approbation you ex- press of the essays :* I have made some * On the Active Powers. — H. P2 63 CORRESPONDENCE OF DR REID. corrections and additions, but such as I hope will not make it necessary to write it over again. But I wish, if I find health and leisure, in summer, to add some essays to go before that on liberty, in order to give some farther elucidation to the principles of morals, both theoretical and practical. I expect your remarks and D. Stewart's upon what is in hand. It will be no inconveni- ence to wait for them two or three, or even four months — I am, dear Sir, Yours most affectionately, Tho. Reid. X. Dear Sir,— In answer to your queries," • The following may serve to explain the allusions in these letters, and, in general, the connection of Reid with the family of Gregory :— The Reverend John Gregory of Drumoak, in the county of Aberdeen, was the common ancestor of two lines, both greatly distinguished for mathema- tical and general ability. His wife was a daughter of David Anderson of Finzaugh, couain-german of the celebrated analyst, Alexander Anderson, the friend and follower of Vieta. By her, he had two sons, David and James, progenitors of the several lines. I. LINE. The elder son, David Gregory of Kinairdy, in the county of Aberdeen, was bred a merchant, and lived che greater part of a long life in Holland He had the singular fortune of seeing three sons Professors of Mathem vticsat the same time in three British uni- versities. Of these sons, the eldest, David, (born 1666, difd 1710.) though inferior to hiB uncle James'in inventive genius, was one of the most illustrious geometers and geometrical authors of his time. .In 1683, elected Professor of Mathematics in the University of Edin- burgh, he w;is, in 1691, by the influence of Newton, nominated Savilian Professor of Astronomy in Ox- ford. His son, David, who died 1767, was student, canon, and dean of Christ Church, and Regius Pro- testor of Modern History in the sameuniversity. The second of these sons, James, succeeded his brother David as Professor of Mathematics in Edin- burgh, and retired in favour of the celebrated Mac- laurin, in 1725. The thirdson, Ckarle$,-wa.s Professor of Mathema- tics in St Andrews from 1707 to 1739, when he-resigned in favour of his son, David, who held the Chair until his death in 1761. Dr Reid's mother was a daughter of David Gre- gory of Kinairdy, and sister of the three Mathema- tical Professors. ir. LINE. James, the younger 6on of the Rev. John Gregory, was born in 1638, and died at the early age of thirty- seven. He was Professor of Mathematics at St And- rew's and Edinburgh j inventor of the Reflecting or Gregorian Telescope; author of several remarkable treatises on optics and geometry; and, altogether, one of the most original mathematicians of his age. His son, Jf?nes t Professor of Medicine in King's College, Aberdeen, was father of a more celebrated son— John, who was Lorn 1724, and died 1773. He was successively Professor of Philosophy and of Medicine in King's College, Aberdeen, and of the Practice of Physic in the University of Edinburgh ; author of the " Comparative View of the State and Faculties of Man and Animals," of the •' Lectures on the Duties and Qualifications of a Physician," of" Elements of the Practice nf Physic," and of ( * A Father's Legacy to his Daughters" His eldest son (Dr Reid's cor. rcsp' nrient)— Jamps, was born 1753, and died 1821. He was Professor of the 'theory, afterwards of the Prnctice, I know not precisely either the year of ray grandfather's death or his age. But all that I have heard agrees very well with the account you mention. He served appren- tice to a merchant in Rotterdam or Camp- vere, and, I believe, continued there till the murder of his elder brother. After he came home, he prosecuted the murderer, (son and heir to Viscount Frendritt, as I have heard, though I find not the title among the extinct or forfeited Peers,) who, being a Roman Catholic, was protected by all the interest of the Duke of York ; but was at last condemned, but pardoned by the crown, and sOon after killed in a naval engage- ment. - Your g-grandfather was so much younger than Kinairdy, as to be educated by him. Kinairdy had no more sons professors than the three you mention, who were all professors before he died. David and James were of the first marriage, and Charles of the second. The two first were settled before the Revolution — David as Professor of Mathematics at Edinburgh, and, I sup- pose, immediately succeeded his uncle, and James as a Professor of Philosophy at St Andrews. I think I have a printed thesis of James, published at St Andrews before the Revolution, which is a compend of Newton- ian philosophy, with some strictures against the scholastic philosophy. With regard to the ten categories in particular, he says there neither are nor can be more than two categories, viz. Data and Q,u£esita.f I be- lieve he was the first professor of philosophy that taught the doctrines of Newton in a Scotch university; for the Cartesian was of Medicine, in the University of Edinburgh ; and author of «* Conspectus Medicine Theoretics"," of ft Philosophical and Literary Essays," and of various other works, distinguished by a talent which promises still to be hereditary. • The murder here alluded to was committed on Alexander Gregory of Netherdeel, eldest son and heirofthe Rev. John Gregory, minister of Drumoak ; and the person indicted for the crime, was James (Crichton) Viscount Frendraught. The Books of Adjournal (records of the Scottish Criminal Court) detail the circumstances of the case. In 1664-, Alex- ander Gregory, who held, in security, a part of the estate of Frendraught, was decoyed by Francis Crichton, the Viscount's uncle, to accompany him to the house of Bognie, where that nobleman then lodged. On the way he was assaulted by Crichton and his servant; and, after he had surrendered his arms, was wounded by them with swords and pistols, and -then carried a prisoner to Bognie. Here he was watched during the night, among others, by the Vis- count, whose servants, nextday, early in a cold morn- ing, threw him across a horse, his wounds undressed and bleeding, and brought him to a lane cottage, where he was left till found by his friends, who con- veyed him to Aberdeen, where, after languishing for a few days, he died. Mr Francis and his servant did not compear. The relevancy of the libel against Lord Frendraught was impugned, on the ground that the crimes libelled being only statutory, and the pannel a minor, they ought not to-pass to an assize. But, though the libel was found relevant, the proof seems to have been defective ; the jury, at least, found a verdict of ac quittal. — lam indebted for this information to Dun- can Gregory and James Maidment, Esquires.— H. t This illustrates a statement in " The Analysis of Aristotle's Logic," ch. ii. sec. 2.— H. LETTERS TO DH JAMES GREGORY. the orthodox system at that time, and con- tinued to be so till 1715. I asked him once how he came to give up his place at St Andrew's on the change of government, and afterwards to take the mathematical chair at Edinburgh. " Faith, nephew," said he, " I never minded politicks much ; but my dearest companions in the college were going out, and I did not like those that were to keep their places ; and I thought it better to go out in good company, than to stay be- hind with ill." I believe Kinairdy's mathe- matical and medical knowledge was the effect of his own study and reading. He was much employed as a physician, not only by the poor, but by the nobility and gentry ; but he took no fees ; and, I conceive, his younger brother and his sons had their mathematical education chiefly from him. He had a barometer, and had a correspon- dence with some foreigners, particularly with Mariotte, on barometrical observations. As a barometer had never been heard of in his country before, he was once in danger of being brought to some trouble by the Pres- bytery on account of it. In Queen Ann's war, Kinairdy employed himself upon an invention for improving the effect of fire- arms, of which he at last completed a model, and sent it to his son David at Oxford, that he might take the opinion of Sir Isaac New- ton about it. I have heard my mother say that he was so sanguine upon this project, that he intended to make a campaign in Flanders himself, and prepared for it. But it is said that Sir I. Newton persuaded the suppression of the invention as destructive of the human species, and that it was never brought to light. I knew a clockmaker in Aberdeen who made all the parts by Kin- airdy's direction ; but never saw them put together, and could give no account of the principles of it. Kinairdy carried his family over to Holland, about the year 1715, as I believe, and, after some time, returned to Aberdeen, and • died soon after, flis widow was alive when I went first to Aberdeen in April 1722 ; but old and bed- rid. I never saw a more ladylike woman ; I was now and then called in to her room, when she sat up in her bed, and enter- tained with sweetmeats and grave advices. Her daughters, that assisted her often, as well as one who lived with her, treated her as if she had been of a superior rank ; and, indeed, her appearance and manner com- manded respect. I don't believe that she could ever descend so far from her dignity and magnanimity as to scold. And the reverence paid her by all her descendants to the last period of her life, seems incon- sistent with that character. She and all her children were zealous Presbyterians. The first wife's children were rather Tories and Ejpiscooalians. I believe she had much ado to keep up her authority with them while they were in the family. David and James, when prosecuting their studies at Edinburgh, used to pass their vacations at Kinairdy ; and very often Dr Pitcairn, or some other fellow-student came along with them ; and, as the master of the family was very much from home, it was not easy for a stepmother to keep them to her rules. One of her stepdaughters married a Mr Cuthbert, of the family of Castlehill, a writer in Aber- deen, and was the mother of David Cuth- bert, who saved millions to the nation in the war before last, by controling the accounts of the commissaries in Germany. Another daughter of the first marriage, married a Mr Innes of Tilliefour. A grandson of hers, Alexander Innes, was a professor of philosophy in Marischal College, Aberdeen. He had a great turn to natural history and to medicine ; but died young. My mother, Margaret Gregory, was the oldest daughter of the second marriage. Besides Charles, there was a George of the second marriage, a merchant in Campvere, and the father of David Gregory at Dun- kirk, and of John Gregory at Campvere. Your uncle, David Gregory, served an apprenticeship to this George Gregory, and married his widow after his death. Charles told me that his brother George fell to the study of mathematics in Holland, and wrote him an account of his discoveries. But Charles bid him mind his mercantile affairs ; for these things had been discovered already by authors he was unacquainted with. The only daughter of the second marriage, besides my mother, who left issue, was -Anne, the youngest daughter, grandmother to James Bartlet, banker in Edinburgh. The story of the watch, to which, I sup- pose, you allude, I have heard very often. By the descendants of the first wife it was imputed to the second wife ; but the de- scendants of the second wife imputed it to the first wife. The first time I was in Dean Gregory's house at Oxford, he told it very well to a large company of Oxonians. He prefaced it by saying that his grand- father had a termagant to his second wife ; but turning to me and another Scotch gen- tleman that was with me, he said, " I beg your pardon, gentlemen, for I don't know but one of you may be come of her." I answered that I believed I had heard the story 'he was about to tell, and heard it imputed to the first wife, of whom he was come ; but it was no matter which : I begged he would proceed. To this he agreed, and proceeded to the story of the watch.* Another story, somewhat similar, is tola of Kinairdy. On some occasion his wife, I know not which wife, insisted very per- * Which is now forgotten in the family. — .H. 70 CORRESPONDENCE OF DR REID. emptorily that lie should correct two of his sons, which, it seems, he was not accus- tomed to do ; but the offence was such, that nothing less would satisfy the wife. He took them to a room where his saddle and bridle hung, and shut the door. What satisfaction he required for the fault I know not ; but, after the matter was compromised, he took the bridle, and lashed the said saddle very unmercifully, and ordered the boys to cry, which they did most pitifully. The mother hearing the noise, thought her boys would be killed, and wanted to interpose, but the door was bolted. She was forced to stand behind the door, and felt every stroke more than either the saddle or the boys, resolving never again to trust her husband with the rod of correction. I have found the printed thesis of James Gregory, above mentioned ; it is printed at Edinburgh, 1690. It would seem that the reform of St Andrew's University, after the Revolution, was not overtaken at that time. The students' names who were to defend the thesis at Salvator College, in St Andrew's, on such a day of June, are all mentioned, to the number of twenty-one. Kinairdy was a Scotch Episcopalian. He wrote memoirs of his own times, which my father, who had read them, told me were unfavourable to the Covenant — the idol of the Presbyte- rians at that time. These Memoirs were in your father's possession, and I suppose are in yours. You see, my dear sir, that I have answered more than I was asked, because I like to dwell upon the subject ; but you must not think nor say that my grandmother was a scold ; she might have strong passions, but no scold ever had her dignity and magnanimity. She had a brother, whom I knew well, who was very like to her — Provost John Gordon. He was long at the head of the magistracy in Aberdeen ; and had been a member of the Scotch Parliament, and was one of the most respected magistrates that ever was in that city — I ever am, dear Sir, yours, Tho. Keid. Aug. 24, 1787. XI. ON THE ORIGIN, PROGRESS, AND THEORY OF LANGUAGE. Dear Sir, — I have read your theory of the moods of verbs* over and over, and shall give you a few trifling remarks when the MS. is returned, or sooner, if I see you sooner. It is not yet sent to Dr Cleghorn, but shall be this week. In the meantime, » Snbiequently printed in "The Transactions of I ine Royal Society of Edinburgh."— H I having the opportunity of my good friend Mr John Dugnid, I send you some reveries on the invention and progress of language. The art of communicating our sentiments by articulate sounds,is certainly, of all human arts, the most ingenious, and that which has required most of thought, of abstraction, and nice metaphysical discrimination. This has led our friend L. M.* to think that it must have been, at first, the work of philo- sophers. I rather consider it as a huge and complicated machine, which was very im- perfect at first, but gradually received im- provements from the judgment andinvention of all who used it in the course of many ages. It is a machine which every man must use, and which he finds of suoh utility and importance, that, if he has any genius, he has sufficient inducement to employ it in making language more subservient to bis purpose. In the natural talents of genius and in- vention, there is no less difference among savages than among philosophers. One savage, in the use of natural signs, will shew great superiority to others in conveying his sentiments distinctly and intelligibly ; and the same superiority he will shew in the use of a rude language of articulate sounds— sometimes by giving a more easy or more agreeable sound to words that are in use; sometimes by distinguishing, by some in- flection or inversion, words or phrases that were before ambiguous ; sometimes by a new metaphorical meaning ; and sometimes by new words or new derivations, where they were wanted. So fond are ingenious men to invent such improvements in language, and so prone the multitude to adopt them, when they please the public taste, that all languages are per- petually changing, according to the beau- tiful simile of Horace — Ut silvai foliis pronos mutantur in annos, $c. In a rude language it iseasyto make improvements; andchanges that are found useful and important, though invented by one man, will soon be adopted by the multitude. Thus the inventions of thousands of in- , genious men, in a succession of ages, all ' employed upon this one machine, bring it • by insensible degrees to its perfection ; as knowledge grows, language grows along with it, till it arrive at that stately form which we contemplate with admiration. The steam engine was invented not much more than a century ago ; but it has re- ceived so many and so great improvements in that short period, that, if the inventor were to arise from the dead, and view it in '■ its improved state, he would hardly be able to discern his own share of the invention. Lord Monboddo H. LETTERS TO DR JAMES GREGORY. n Language is like a tree, which, from a small seed, grows imperceptibly, till the fowls of the air lodge in its branches, and the beasts of the earth rest under its shadow. The seed of language is the natural signs of our thoughts, which nature has taught all men to use, and all men to understand. But its growth is the effect of the united energy of all who do or ever did use it. One man pushes out a branch, another a leaf, one smooths a rough part, another lops off an excrescence. Grammarians have, without doubt, contributed much to its regularity and beauty 5 and philosophers, by increasing our knowledge, have added many a fair branch to it ; but it would have been a tree without the aid of either. The rudest tribes of men soon find lan- guage to express their confined wants and desires ; and the natural love of analogy will produce much analogy even in the lan- guage of savages. We see that children of two or three years old, having got a few plurals, without being taught, form new ones analogically, and often, in the pursuit of analogy, break chrough the rules of grammar. A man born deaf, who has no opportunity of conversing with other deaf men, has to invent a language for himself, along with the additional labour of teaching others to un- derstand it- One who has had access to know to what degree of perfection some deaf men have carried their art of commu- nicating their thoughts, will not think it incredible that a nation flourishing in arts and sciences should, in a course of ages, by their united efforts, bring language to all the perfection it has ever attained. In speech, the true natural unit is a sen- tence. No man intends less when he speaks ; what is less than a complete sen- tence is not speech, but a part or parts of speech; to divide a sentence into parts requires greater abstraction than to divide the unit into fractions of a unit. It is, therefore, extremely probable that men ex- pressed sentences by one complex sound or word, before they thought of dividing them into parts, signified by different words. One word signified, give me bread ; another, take ' bread ; another, eat bread ; another, bake bread. As all these sentences have some- thing common in their meaning, the natu- ral love of analogy would lead to some- thing common in the word by which they were expressed; and in the progress -of language, that which was common in the sound of all these sentences might be sepa- rated from that which was proper to each ; and being thus separated, it becomes that part of speech which we call a substantive * This is an important truth, the ignorance, of which is seen in our perverted systems of Grammar, Logic, and Psychology— H. noun, signifying bread, which substantive will be fit to make a part of many other sentences. Thus the object, or accusative, may be, as it were, cut out of the sentence, so as to form a word by itself, though originally it was only a part of a word. Another set of sentences — such as, / love Martha, You love Mary, John loves Matilda — might lead men to separate what is com- mon in the word by which each of these three sentences is expressed, from what is proper to each, and by that means to have a word for the verb love. To shew how all the parts of speech may be cut out of words that signify whole sen- tences, by separating that part of the sound which is common to many sentences, from that which is proper to each, would be more tedious than difficult, and may easily be conceived. By dividing the sound, the mental abstraction is made easy, even to rude men, who, without some aid of this kind, would find it above their reach. Such division facilitates greatly the use of lan- guage, and, therefore, when once begun, will go on. That the parts of speech should be con- ceived before speech was in use, and that speech should at first be formed by putting together parts of speech, which before had got names, seems to me altogether incred- ible ; no less incredible than if it should be said that before men had the conception of a body, they first formed the conception of matter, then the conception of form, and, putting these two together, they got the conception of body, which is made up of matter and form. Perhaps, in the language of some savages, all the parts of speech have not yet been separated into different words. Charlevoix has given a very full account of some of the Canadian languages. I quote him from memory, having read his history of Canada, I think, about forty years ago ; but, as it first led me into this speculation, I remem- ber it the better. He says, "of one of their languages, (I think that of the Hurons,) that in each of their villages there is a public orator chosen, who makes it the whole study of his life to speakthe language with propriety and force ; that the people are very nice judges of the defects and excellencies of their orators ; so that there are very few of them that can perfectly please the public ear ; that their verbs have as many moods and tenses as the Greek verbs have, and, besides this, that the accusative or object always makes a part of the verb. Thus, one verb signi- fies to drink wine ; another, to drink water ; one, to kill a brother ; another, to kill an ene- my ; so that the verb very often expresses the whole sentence. 72 CORRESPONDENCE OP DR REID. I believe, in all languages of nations which we account civilized, the several parts of speech have been separated from one an- other, and are often expressed by words proper to them. But in all of them, and in some more than in others, several parts of speech are often combined in one word, not from necessity, but for the sake of elegance and beauty. Thus, in the Latin and Greek verbs, be- sides the radical signification of the verb, its voice, mood, tense, person, and number are all expressed in one word. In nouns, both substantive and adjective, we have the noun, together with its case, number, and gender, in one word. Nor is this owing to a want of words in those languages to ex- press separately those accidents of verbs and nouns. It seems rather to be a matter of choice, to give greater beauty and strength to the language. By this expedient, much may be said in few words — and these, lofty and sonorous words, with a beautiful variety and harmony of termination, and great power of inversion ; which are qualities of great importance in poetry and eloquence. In language, as in many other things, necessity, convenience, and long practice, have, without the rules of art, produced artifices, which the artist or the philosopher has reason to admire, which, sitting in his chair, he would never have been able to invent, and which, now that they are in- vented, he finds it very difficult to reduce to principles of art. I believe the principles of the art of lan- guage are to be found in a just analysis of the various species of sentences. Aristotle and the logicians have analysed one species — vO wit, the proposition. To enumerate and analyse the other species, must, I think, be the foundation of a just theory of language. —I am, dear Sir, yours affectionately, Tho. Reid. Aug. 26, 1787. XII. [1788.] Dear Sir, — I received yours of Feb. 19, and last evening received, by the fly, the very acceptable present of the new edition of your father's works, for which I heartily thank you. I have read the Life, which I think well wrote. I am much obliged to the author* of it for the notice he has taken of me; but I wish he had spared some epithets, which I could not read to myself without a blush ; I have exceptions to some things in the narrative, but they relate to unimportant circumstances. The quotation from " Whiston's Memoirs" de- lighted me, and does honour to Scotland.-)- • Lord Woodhouselee. — H. t It iB of the following purpott : — Speaking of Dr Perhaps it might have been added, that James, the brother of David, was at that time teaching the same doctrine, as a Pro- fessor of Philosophy, in another Scotch university. I have by me a thesis he published in 1690, which is a compend of the conclusions of Newton's " Principia," I have always heard, by tradition, that D. Gregory, the astronomer, was chosen to be preceptor to the Duke of Gloucester, Queen Ann's son ; but whether his entering upon that office was prevented by his death, or by the death of the young prince, I know not. I have also heard that the Profession of Modern History in Oxford was erected in favour of his son, David, when he came home from his travels.* I am happy in the account you give me of our friend, William. I hope he will continue the race of the Gregories, if you do not — which, however, I do not yet de- spair of. Our University has sent a petition to the House of Commons, in favour of the African slaves. I hope yours will not be the last in this humane design ; and that the Clergy of Scotland will likewise join in it. I comfort my greyhairswiththe thoughts that the world is growing better, having long resolved to resist the common sentiment of old age, that it is always growing worse. I am grown so deaf that I can only converse with one person, and that when he speaks into my left ear ; but I hope to resist that depression of spirits which commonly at- tends that disorder. I can see people con- versing together without any uneasiness ; the only difficulty is, when a laugh is raised, whether to laugh at one does not know what, David Gregory, when Professor of Mathematics at Edinburgh, Whiston says — « He had already caused several of his scholars to keep acts, as we call them, upon several branches of the Newtonian philosophy, while we at Cambridge, poor wretches ! were ignomi- niously studying the fictitious hypotheses of the Carte- sian." — tVhiston's Memoirs, p. 32. — There is in this, however, no just ground of panegyric on Scotland, In the intrusive system of the English universities, where the tutor has illegally superseded the professor, all change from one set of doctrines to a better, must be the tardy and painful work of time and necessity. The evolutions of a university are prompt and easy where each department of its cyclopaedia is separately taught by an able professor; whereas a university which abandons instruction, in all branches, to any individual of a host of tutors — the majority of whom assume the office ol instructor for their own couve. nience, though without the ability adequate' to dis- charge its duties — such a university must be content, not only always to teach little, and that little ill, but to continue often for a long time to teach what is elsewhere obsolete or exploded. Accordingly, in Newton's own university, the Cartesian theories con- tinued to be taught as the orthodox doctrine, after the Newtonian physics had, in other univetsities, super- seded the Cartesian. Andwhy? Simply because, in Cambridge, instruction was carried on by tutors ; and the majority of the Cambridge tutors, educated in the old system, were unable or unwilling to qualify them- selves to become instructors in the new. — H. • David Gregory, the son, was.certainlyTSr** Pro- fessor in the chair ol Modern History and Languages, founded by George I. — H. LETTERS TO DR JAMES GREGORY. 73 or to be grave when other people laugh. I am very glad to hear that Dug. Stewart lectures in physicks so acceptably, but wish his health be not affected by his being over- wrought — I am, dear Sir, very affection- ately yours, Tho. Reid. XIII. ON USURY. I am much pleased with the tract you sent me on usury." I think the reasoning unanswer- able, and have long been of the author's opinion, though I suspect that the general principle, that bargains ought to be left to the judgment of the parties, may admit of some exceptions, when the buyers are the many, the poor, and the simple — the sellers few, rich, and cunning; the former may need the aid of the magistrate to prevent their being oppressed by the latter. It seems to be upon this principle that por- tage, freight, the hire of chairs.and coaches, and the price of bread, are regulated in most great towns. But with regard to the loan of money in a commercial state, the excep- tion can have no place — the borrowers and lenders are upon an equal footiug, and each may be left to take care of his own interest. Nor do I see any good reason for the inter- position of law in bargains about the loan of money more than in bargains of any other kind. I am least pleased with the 10th letter, wherein he accounts for the infamy of usury. In one of the papers you mention, (which I give you liberty to use as'you please,) I have attempted an account of that phenomenon, which satisfies me more than his account does. — I am, dear Sir, Yours most affectionately, Tho- Reid. Glasgow, 5th Sept. 1788. XIV. CAUSE — PHYSICAL CAUSE — LAWS OF NATURE AGENT POWER AND ACTIVITY. My Dear Sir,— On Monday evening I received your book,f with the letter in- closed. The book I shall peruse at leisure with the eye of a critick ; but, as it is proper to acquaint you soon of my having received it safe, I shall now answer your letter, though perhaps in too much haste. Your * '''Letters On Usury," by Mr Jeremy Bentham, addressed to George Wilson, Esq., (Dr Gregory's triend,) and published. by Mr Wilson in 1787.— H. f The " Philosophical and I iterary Essays," or rather their introduction, which was in great part printed several years belore publication.— H. intention of inscribing the book, if published, to me, I account a very great honour done me ; and, if you do not alter your mind, would not be so self-denying as to decline it ; but, as a real friend, I think you ought to inscribe it to some man in power that may be of use to you, though I hate dedi- cations stuffed with flattery to great men. Yet I know no reason why a man of your time of life may not court the notice of a great man by a dedication, as well as by a visit. When I inscribed a book to you, my situation was very different. I was past all hopes and fears with regard to this world ; and, indeed, had Lord Kaimes been alive, intended to have addressed it to him. When he was dead, there was not a man of his eminence that I had so much ac- quaintance with as to j ustify such an address. I therefore seriously wish you to spend a second thought upon this subject ; and not to suffer your friendship, of which I need no new proof, to lead you to do an impru- dent thing, and what the world would think such, or even perhaps construe as a con- tempt put upon your great friends. * As to the two points wherein you and I differ, after what you have said of them ia this letter, I am really uncertain whether we differ about things or only about words. You deny that of every change there must be an efficient cause, in my sense — that is, an intelligent agent, who by his power and will effected the change. But I think you grant that, when the change-is not effected by such an agent, "it must have a physical cause — that is, it must be the necessary consequence of the nature and previous state of things unintelligent and inactive. I admit that, for anything I know to the contrary, there may be such a nature and state of things which have no proper ac- tivity, as that certain events or changes must necessarily follow. I admit that, in such a case, that which is antecedent may be called the physical cause, and what is necessarily consequent, may be called the effect of that cause. I likewise admit, laws of nature may be called (as they commonly are called) phy- sical causes — in a sense indeed somewhat different from the former — because laws of nature effect nothing, but as far as they are put to execution, either by some agent, or by some physical cause ; they being, how- ever, our neplus ultra in natural philosophy, which professes to shew us the causes of natural things, and being, both in ancient and modern times, called causes, they have by prescription acquired a right to that name. I think also, and I believe you agree with » It is needless to say that Dr Gregory did not comply with this prudent advice. The " Essaifc" 1 are dedicated to Keid.~ U. 74 CORRESPONDENCE OF DR REID. me, that every physical cause must be the work of some agent or efficient cause. Thus, that a body put in motion continues to move till it be stopped, is an effect which, for what I know, may be owing to an inherent pro- perty in matter ; if this be so, this pro- perty of matter is the physical cause of the continuance of the motion ; but the ultimate efficient cause is the Being who gave this property to matter. If we suppose this continuance of motion to be an arbitrary appointment of the Deity, and call that appointment a law of nature and a physical cause ; such a law of nature requires a Being who has not only enacted the law, but provided the means of its being executed, either by some physical cause, or by some agent acting by his order. If we agree in these things, I see not wherein we differ, but in words. I agree with you that to confound the notion of agent or efficient cause with that of physical cause, has been a common error of philosophers, from the days of Plato to our own. I could wish that the same gene- ral name of cause had not been given to both, as if they were two species belonging to the same genus. They differ toto genere. For a physical cause is not an agent. It does not act, but is acted upon, and is as passive as its effect. You accordingly give them different generical names, calling the one the agent, and not the cause — the other the cause, but not the agent. I approve of your view in this ; but think it too bold an innovation in language. In all writing, preaching, and speaking, men have been so much accustomed to call the Deity the first cause of all things, that to maintain that he is no cause at all, would be too shocking. To say that the world exists without a cause, would be accounted Atheism, in spite of all explications that could be given of it. Agency, efficiency, operation, are so conjoyned in our concep- tions with a cause, that an age would not be sufficient to disjoyn them. The words agent and action are not less ambiguous than cause and causation ; they are applied, by the most accurate thinkers and speakers, to what you call physical causes. So we say, one body acts upon another, by a stroke, by pressure, by attrac- tion or repulsion ; and in vain would one attempt to abolish this language. We must bear with the imperfections of language in some degree ; we are not able to make it so philosophical as we wish. To remedy the ambiguity of cause and agent as far as possible, without too bold an innovation, I say that each of these words has two meanings — a lax and popular meaning, and a philosophical. In the po- pular meaning, both are applied to what you call a physical cause. In the strict or philo- sophical meaning, both are applied only to what you call an agent — I, an efficient cause. I choose to distinguish the philoso- phical meaning of cause, by calling it an efficient cause ; and to distinguish the philosophical meaning of agent, by calling it an agent in the strict and proper sense. You distinguish the philosophical mean- ing of these two ambiguous words from the popular, by appropriating one to the philo- sophical meaning, and the other to the popular. Is not this the difference between you and me ? It is remarkable that the philosophical meaning of those two words, and of the others that depend upon them, must have been the first, and the popular meaning a corruption of the philosophical, introduced by time, but so deeply rooted in the struc- ture of all languages, that it is impossible to eradicate it ; for nothing external to us could introduce into the human mind the general notion of priority and constant con- junction, but nothing farther. Power and activity are first conceived from being conscious of them in ourselves. Conceiving of other beings from what we know of ourselves, we first ascribe to them such powers as we are conscious of in our- selves. Experience, at least, informs us that the things about us have not the same powers that we have ; but language was formed on a contrary supposition before this discovery was made, and we must give a new, and perhaps a very indistinct, mean- ing to words which before had a clear and distinct one. As to the other difference you mention between you and me, I have quite forgot it. But I think one can hardly be too cautious of denying the bona Jides of an antagonist in a philosophical dispute. It is so bitter a pill, that it cannot be swallowed without being very well gilded and aromatized. I cannot but agree with you that assent or belief is not a voluntary act. Neither is seeing when the eyes are open. One may voluntarily shut his bodily eyes, and perhaps the eye of his understanding. I confess this is mala fides. But as light may he so offensive that the bodily eye is shut involun- tarily, may not something similar happen to the eye of the understanding, when brought to a light too offensive to some favourite prejudice or passion, to be endured?* As soon as I have done with your book, I shall execute your commission to Mr Ar- thur — I am, dear Sir, yours very sincerely. Tho. Ekid. Thursday, July 30, 1789. * This passage (" But I think"—" be endured f •') is quoted in the Introduction to Dr Gregory's Essays, p. 316. ^H. LETTERS TO DR JAMES GREGORY. 75 XV. ARISTOTELIC SPECIES OP CAUSES — ORIGIN OP NOTIONS OP CAUSE AND POWER — WHAT ES- SENTIAL TO THE NATURE OF CAUSE — DIS- TINCTION OP PHYSICAL AND METAPHYSICAL CAUSES. Remarks on the Introduction.'' 1. I humbly think you are too severe against Aristotle and Plato, especially the former, f Two hundred years ago, it was proper to pull him down from the high seat he held ; but now he is sufficiently humbled, and I would not have him trampled upon. I confess that his distinction of causes into four kinds is not a division of a, genus into its species, but of an ambiguous word into its different meanings, and that this is the case with many of his divisions. But, in>the in- fancy of philosophy, this ought to be corrected without severity. It was more inexcusable in many philosophers and divines of the scholastick ages to handle every subject in one method, namely, by shewing its four causes — Efficient, Material, Formal, and Final. A very learned divine, whose compend was the text-book in the school where I was taught, treating of the creation, when he comes to the material cause, pronounces it to be nihil. If Aristotle had treated of his materia prima in this method, he must have made the material cause to be the thing it- self, and all the three other causes to be nihil ; for it had no form, no efficient, con- sequently no end. But the absurdity of making everything to have four causes, can- not, I believe, be imputed to Aristotle. 2. You challenge him with a violation of propriety in the Greek language. J I am dis- posed to take it upon the authority of Aris- totle, as a man who understood Greek better than any modern, that the word Hmn was sometimes used to signify the form, some- times the matter of a thing. If these were not popular meanings of the word, might they not be philosophical, and perhaps to be found only in the writings of philosophers, which are now lost ? But I cannot think that Aristotle would have given these mean- ings without authority ; and I think it bold in any modern to impute this to him. 3. You are likewise severe upon the n ij- «. || May it not be said that it is very like the sup- posed principle of change, which, in page xvii., you make the general meaning of the word cause ? 4. You seem to think -{end of page xxi.) that there are different kinds of causes, each * " Introduction to the Eaaay," &c. printed in part,— H. 1 Vide «'E66ays," Introduction, p. xvi. eg.— H. } Ibidem, p. xvii — H. |] Ibidem, p. xvii.— H. having something specifick in its relation to the effect. I know not what the kinds are which you have in your eye, and therefore speak in the dark upon this point. I mean onely to put you upon your guard that they be really species of the same genus, that you may not fall under the censure you have passed upon Aristotle. You will forgive my offering this caution, because I apprehend that there is one ori- ginal notion of cause grounded in human nature, and that this is the notion on which the maxim is grounded — that every change or event must have a cause. This maxim is so universally held, and forces itself upon the judgment so strongly, that I think it must be a first principle, or what you call a law of human thought. And I think the only distinct and true meaning of this maxim is, that there must be something that had power to produce the event, arid did pro- duce it. We are early conscious of some power in ourselves to produce some events ; and our nature leads us to think that every event is produced by a power similar to that which we find in ourselves — that is, by will and exertion : when a weight falls and hurts a child, he is angry with it — he attributes power and will to everything that seems to act. Language is formed upon these early sentiments, and attributes action and power to things that are afterwards discovered to have neither will nor power. By this means, the notion of action and causation is gradually changed ; what was essential to it at first is left out, while the name remains : and the term cause is applied to things which we believe to be inanimate and passive. I conceive that, from the original notion or sentiment above described, all the dif- ferent notions of cause have been derived, by some kind of analogy, or perhaps abuse ; and I know not but the T o J| ff may compre- hend them all, as well as any other general name, as they are so heterogeneous. A law plea is the cause of a litigation. The motive that induces a great body of men to act in concert, is the cause of a revolu- tion in politicks. A law of nature is the cause of a phenomenon in physicks, or, perhaps, the cause is another phenomenon which always goes before it. The cause of the universe has been by some thought to be necessity, by others chance, by others a powerful intelligent being. I think it is a good division in Aristotle, that the same word may be applied to dif- ferent things in three ways — univocally, analogically, and equivocally. Univocally, when the things are species of the same genus ; analogically, when the things are related by some similitude or analogy; equi- vocally, when they have no relation but a common name. When a word is analogi- 76 CORRESPONDENCE OF DR REII>. cally applied to different things, as, I be- lieve, the word cause is, there must be an original meaning from which the things related to it have borrowed the name ; and it happens not unfrequently that the origi- nal notion loses the name by disuse, while the relatives monopolize it ; as in the Eng- lish words, deliberate, suspense, project, and many others. The vulgar, in their notion even of the physical cause of a phEenomenon, include some conception of efficiency or productive influence. So all the ancient philosophers did. Itaque non sic causa intelligi debet, ut quod cuique antecedat, id ei causa sit, sed quod efficienter antecedit. — Cicero. Modern philosophers know that we have no ground to ascribe efficiency to natural causes, or even necessary connection with the effect. But we still call them causes, including nothing under the name but pri- ority and constant conjunction. Thus the giving the name of causation to the relation of connected events in physicks, is, in mo- dern philosophers, a kind of abuse of the name, because we know that the thing most essential to causation in its proper meaning — to wit, efficiency— is wanting. Yet this does not hinder our notion of a physical cause from being distinct and de- terminate, though, I think, it cannot be said to be of the same genus with an effi- cient cause or agent. Even the great Bacon seems to have thought that there is a latens processus, as he calls it, by which natural causes really produce their effects ; and that, in the progress of philosophy, this might be discovered. But Newton, more enlightened on this point, has taught us to acquiesce in a law of nature, according to which the effect is produced, as the utmost that natural philosophy can reach, leaving what can be known of the agent or efficient cause to metaphysicks or natural theology. This I look upon as one of the great dis- coveries of Newton ; for I know of none that went before him in it. It has new- modelled our notion of physical causes, but, at the same time, carried it farther from what I take to be the original notion of cause or agent. If you have found, as you seem to say, (page xxii.,) that the different relations of things, which we call cause and effect, differ only as species of the same genus, and have found the general notion which comprehends them all under it — this, indeed, is more than I am able to do. Supposing it to be done, I should think that the genus, being an abstract notion, would be capable of a just definition. Yet I do not find fault with your declining to set out by giving the definition ; for I conceive you may, with great propriety, pave the way to it by » preliminary induction. XVI. ON CAUSE OBJECTS OF GEOMETRY POWER — AGENCY, &C. [No dale.] My Dear Sir, — I must thank you, in the first place, for your attention to my in- terest in writing to Dr Rose what you in- formed me of in your answer to my last. I received your three volumes' on Wed- nesday evening, with the letter and plan of the Essay. ...... Volume First. In the induction made to prove that men have a notion of the relation of cause and effect, this case ought to be particularly in the view of the author, (as I take it to be the case that really exists) — to wit, that cause and effect, from the imperfection of langu- age, signifie many different relations, and yet, by those who write and think dis- tinctly, will be used without ambiguity; the things of which they are predicated ex- plaining sufficiently what relation is meant. This is the case of many words that have various meanings really different, though, perhaps, somewhat similar or analogous. It is remarkably the case of prepositions. Yet such words as prepositions are used with- out ambiguity by those who think distinctly. How many relations are expressed by the preposition of ? — and yet, when it is put be- tween two words, we are never at a loss for its meaning. In Aristotle's days, a cause meant four things — to wit, the Efficient, the Form, the Matter, and the End. Yet, when it was used by a good writer, it was easy to see in which of these senses it was meant. With us the word cause has lost some of these 'four meanings, and has got others to supply their places, and, perhaps, has not, in one language, all the meanings which it has in another. Perhaps, therefore, it may be said, that all men have many no- tions of cause and effect, and some men more than others; the same observation may, I think, be applied to the words Power, Agent, and Activity. To give you a hint of my notion of the word cause, I think it has one strict and philosophical meaning which is a single re- lation, and it has a lax and popular meaning which includes many relations. The popu- lar meaning I think I can express by a definition. Causa est id, quo posito ponitur I The MS. of the Essay itself. The Essay wu probably considerably modified before publication ; and 1 have been unable to attempt the task of discover, ing how far, and to .what pages of the published book, the following remarks apply. H. LETTERS TO Dil JAMES GREGORY. 77 Effeetus, quo sublato tollitur. This, you will easily see, includes many relations, and, I believe, includes all thatinany language are expressed by cause, thoughjnsomelanguages some of the relations included under the definition may not be called causes, on ac- count, perhaps, of their having some other word appropriated to signify such relations. In the strict philosophical sense, I take a cause to be that which has the relation to the effect which I have to my voluntary and deliberate actions ; for I take this notion of a cause to be derived from the power I feel in myself to produce certain effects. In this sense, we say that the Deity is the cause of the universe. I think there is some ambiguity in your use of the words The notion of a cause. Through a considerable part of Vol. I. it means barely a conception of the meaning of the word cause ; then suddenly it means some opinion or judgment about the word cause, or the thing meant by that word. The last must be the meaning when you speak of the notion of a cause being true or false, being condemned or justified. The bare conception of a cause, without any opinion about it, can neither be true nor false. It is true that notion often signifies opinion ; but when, in a train of discourse, it has been put for simple conception, and then immediately for opinion, the reader is apt to overlook the change of signification, or to think that the author means to impute truth or falsehood to a bare conception, without opinion. The same thing I observe when you speak of the notion of power, vol. II. p. 19. Page 40, &c What is said about the non-existence of the objects of geometry, I think, is rather too strongly expressed. I grant that they are things conceived without regard to their existence ; but they are pos- sible modifications of things which we dayly perceive by our senses. We perceive length, breadth, and thickness : these attributes do really exist. The objects of geometry are modifications of one or more of these, accu- rately conceived and defined. Nor do I think it can be said, without great exceptions, that the notions of the objects of geometry are not common among man- kind. The notions of a straight and a curve line, of an angle, of a plain surface, and others, are common; though, perhaps, in the minds of the vulgar, not so accurately de- fined as in those of geometers. The more complex geometrical conceptions of cycloids and other curves, are only artificial com- positions of more simple notions which are common to the vulgar. Hence, a man of ordinary capacity finds no difficulty in under- standing the definitions of Euclid. All the difficulty lies in forming the habit by which the name, and an accurate conception of its meaning, are so associated, that the one readily suggests the other. To form this habit requires time, and in some persons much more than in others. Page 68. — You may use freedom with Aristotle, because he won't feel it. But I would not have you laugh at the restorer of ancient metaphysicks* in publick while he is alive. Why hurt a man who is not hurting you ? Page 70. — I thought the animal implume bipes was Plato's definition, and I think I quoted it as his ; but you may examine. I think it is Diog. Laertius that says so ; but I am not sure, nor have I the book here.-)- What you say of definitions in natural history, chemistry, and medicine, may per- haps be taken by some persons as a disap- probation of definitions in those sciences. Would it not be proper to guard against this misconstruction ? I think them very useful to the present age, and that they may be still more useful to future ages, though you observe, very justly, that we can- not reason from them as we do from mathe- matical definitions. The most common words may flow with the flux of time, and have their meaning contracted, enlarged, or altered. Definition seems to be the only mean of fixing them to one meaning, or, at least, of shewing what was the meaning when that definition had authority. Volume Second. After what I have already said, you will not be surprized to find me one of those who think that the notions of Power and of Agency or Activity, have a- share in the rela- tion of Cause and Effect. I take all the three words to have a lax and popular meaning, in which they are nearly related ; and a strict and philosophical meaning, in which also they have the same affinity. In the strict sense, I agree with you that power and agency are attributes of mind onely ; and I think that mind onely can be a cause in the strict sense. This power, indeed, may be where it is not exerted, and so may be without agency or causation ; but there can be no agency or causation with- out power to act, and to produce the effect. As far as I can judge, to everything we call a cause we ascribe power to produce the effect. In intelligent causes, the power may be without being exerted ; so I have power to run, when I sit still or walk. But in .inanimate causes, we conceive no power but what is exerted ; and, therefore, mea- sure the power of the cause by the effect • Lord Monboddo.— H. t See Laertius, L. vi. Seg. 40. The definition i. Plato's H. CORRESPONDENCE OF DR REID. which it actually produces. The power of an acid to dissolve iron is measured by what it actually dissolves. We get the notion of active power, as well as of cause and effect, as I think, from what we feel in ourselves. We feel in our- selves a, power »to move our limbs, and to produce certain effects when we choose. Hence, we get the notion of power, agency, and causation, in the strict and philosophical sense ; and this I take to be our first notion of these three things. If this be so, it is a curious problem in human nature, how, in the progress of life, we come by the lax notion of power, agency, cause, and effect, and to ascribe them to things that have no will nor intel- ligence. I am apt to think, with the Abbe 1 Raynal, " that savages," (I add children as in the same predicament,) " wherever they see motion which they cannot account for, there they suppose a soul." Hence chey ascribe active power and causation to sun, moon, and stars, rivers, fountains, sea, air, and earth ; these are 'conceived to be causes in the strict sense. In this period of society, language is formed, its funda- mental rules and forms established. Ac- tive verbs are applied onely to things that are believed to have power and activity in the proper sense. Every part of nature which moves, without our seeing any exter- nal cause of its motion, is conceived to be a cause in the strict sense, and, therefore, is called so. At length, the more acute and speculative few discover that some of those things which the vulgar believe to be ani- mated like themselves, are inanimate, and have neither will nor understanding. These discoveries grow and spread slowly in a course of ages. In this slow progress, what use must the wise men make of their dis- coveries ? Will they affirm that the sun does not shine nor give heat, that the sea never rages, nor do the winds blow, nor the earth bring forth grass and corn ? If any bold spirit should maintain such para- doxes, he would probably repent his teme- rity. The wiser part will speak the com- mon language, and suit it to their new no- tions as well as they can ; just as philoso- phers say with the vulgar, that the sun rises and sets, and the moon changes. The philosopher must put a meaning upon vul- gar language that suits his peculiar tenets as well as he can. And, even if all men should become philosophers, their language would still retain strong marks of the opi- nions that prevailed when it was first made. If we allow that active verbs were made to express action, it seems to be a necessary consequence, that all the languages we know were made by men who believed almost every part of nature to be active, and to have inherent power. Volume Third. The philological discussion is new to me j and it would require more time in my slow way to make up my mind about it, than you allow me. But the general principle — that every distinction which is found in the structure of i common language, is a real distinction, and is perceivable by the com- mon sense of mankind — this I hold for cer- tain, and have made frequent use of it. I wish it were more used than it has been ; for I believe the whole system of metaphy- sicks, or the far greater part, may be brought out of it ; and, next to accurate reflexion upon the operations of our own minds, I know nothing that can give so much light to the human faculties as a due considera- tion of the structure of language. From this principle, you prove to my satisfaction that there is a real distinction between the relation which a living agent has to his action, and the relation between an inanimate and the effect of which it is the cause, mean, or instrument. But I know no language in which the word cause is confined to inanimate things, though, perhaps, it may be more frequently applied to them than to things that have life and intelligence. If I were convinced that it cannot be said, in a plain, literal sense, that I am the cause of my own actions, or that the Deity is the cause of the universe — if I were convinced that my actions, or the production of the universe, are not effects, or that there must be a cause of these effects distinct from the agent, I should in this case agree to your reasoning. The rule of Latin syntax from which you reason, seems, indeed, to suppose that all causes are inanimate things, like means and instruments ; but I desiderate better authority. I am not sure but power and agency are as often ascribed to inanimate things as causation. Thus we speak of the powers of gravity, magnetism, mechanical powers, and a hundred more. Yet there is a kind of power and agency which you acknowledge to belong only to mind. Your system, if I comprehend it, (which, indeed, I am dubious about,) seems to go upon the supposition that power and agency belong onely to mind, and that in language causation never belongs to mind. If this be so, you and I may, after all, differ only about the meaning of words. What you call an agent, and a being that has power, that I call a cause with regard to every ex- ertion of his power. That which alone you call a cause, I think is no cause at all in the strict sense of the word ; but I acknowledge it is so in the lax and popular sense. LETTERS TO DR JAMES GREGORY. 79 In these remarks I thought friendship obliged me to lay aside all regard to friend- ship, and even to indulge a spirit of severity that seems opposite to it. I hope you will make allowance for this. For, in reality, I have such an opinion of your judgment and taste, that I cannot help suspecting my own where thev differ. XVII. AN AMBIGUITY OF HUME — MEANINGS OF WILL AND VOLITION POWER. Motive — Sect 1. 27. [Page 21, published work.]— It does not appear to me, that the long pas- sage quoted from Mr Hume's reconciling project, is so full of ambiguous expressions and hypothetical doctrine, as it is said to be ; though I think it is very clearly shewn to be full of weak reasoning. I think he does not confound a constant conjunction with a necessary connection, but plainly dis- tinguishes them ; affirming, that the fiist is all the relation which, upon accurate reflec- tion, we are able to perceive between cause and effect ; but that mankind, by some pre- judice, are led to think that cause and effect have moreover a necessary connection; when at the same time they acknowledge onely a constant conjunction betweenmotive and action ; so far I see no obscurity or ambiguity. The words constant conjunction and necessary connection, I think, are the best that can be used to express the meaning of each, and the difference between them. At the same time, to suppose, without assigning any reason for the supposition, that the constant conjunction of cause and effect leads men to believe a necessary con- nection between them, but that the con- stant conjunction between motive and action has no such effect, appears to me very weak and unphilosophical ; and this account of the phenomenon of men's putting a differ- ence between the relation of motive and action, and the relation of cause and effect, does not appear to me to deserve the epithet you give it, of very ingenious. The last part of the quotation, beginning with — " Let any one define a cause without comprehending," &lc* I think has a distinct * The whole sentence is as follows : — It is from Hume's " Inquiry concerning the Human Under, standing," sect. viii. part 1 . prope Jinem. " Let any one define a cause, without comprehending, asapart of the definition, a necessary connection with its effect ; and let himishew distinctly the origin of the idea, ex pressed by the definition, and I shall readily give up Die. whole controversy." — Dr Reid, in his remarks on this passage, would be right, did Hume mean by necessary connection, a really necessary con. nection, and not merely a feeling of necessity in us, and that not a priori, but apo ieriori— not the meaning ; but that meaning is so imperti- nent to his purpose, and so contrary to his principles, that I cannot help thinking that he meant to say the very contrary of what he says ; and that the word without has slipt into the sentence by an oversight of the author or printer. For, does not he him- self define a cause without comprehending, as a part of the definition, a necessary con- nection between the cause and the effect ? Does he not maintain that we have no idea of necessary connection ? He certainly meant to say, that he would give up the whole controversy, if any one could shew that we have such an idea, and not to say that he would give up the controversy, if any one could give a definition of cause without comprehending that idea. Were I to comment upon this passage in the Bentleian style, I would say dele without, rneo periculo. After all, how he should think that the bulk of mankind have, without reason, joyned the idea of necessary con- nection to that of constant conjunction, in the relation of cause and effect, when man- kind have no such idea, I cannot account for. Of the Notion of Instrument. 66, &c. — I am not pleased with the three different meanings you put upon the word volition, nor do I think it ambiguous. Will is indeed an ambiguous word, being some- times put for the faculty of willing ; some- times for the act of that faculty, besides other meanings. But volition always sig- nifies the act of willing, and nothing else. Willingness, I think, is opposed to unwil- lingness or aversion. A man is willing to do what he has no aversion to do, or what he has some desire to do, though perhaps he has not the opportunity ; and I think this is never called volition. Choice or preference, in the proper sense, is an act of the understanding ; but some- times it is improperly put for volition, or the determination of the will in things where there is no judgment or preference ; thus, a man who owes me a shilling, lays down three or four equally good, and bids me take which I choose. I take one without any judgment or belief that there is any ground of preference — this is merely an act of will that is a volition. An effort greater or less, I think, always accompanies volition, but is not called vo- lition. There may be a determination of will to do something to-morrow or next week. This, though it be properly an act offspring acknowledge, but of blind habit. It is here the part of ihe sceptic, not to disprove the subjective phaenomenon of necessity, but to shew that it is ille- gitimate and objectively barren.— H. so CORRESPONDENCE OF DR REID. of will, is not called volition, because it has a proper name of its own — we call it a reso- lution or purpose ; and here the effort is suspended till the purpose is to be ex- ecuted. I apprehend that, in dreaming, the effort accompanies volition, as well as when we are awake ; but in most persons the effort in dreaming produces little or no motion in the body, as is the case in palsy. When a hound dreams, we see a feeble attempt to move his limbs and to bark, as if he had the palsy. And a man dreaming that he cries desperately for help, is often heard to make a feeble attempt to cry. Power. 16, &c I humbly think that my power to ride or to walk, and the king's power to call or to dissolve a parliament, are different kinds, or rather different meanings of the word power. In the former meaning, every- thing depending upon my will is in my power, and consequently my will itself ; for, if I had not power to will, I could have no power to do what depends upon my will. In the second meaning, power signifies a right by the law or by the constitution, according to that maxim of law, Nihil pos- sum quod jure non possum. In another law sense, we say — It is part of the king's prerogative that he can do no wrong. The meaning of this is not that he has no legal right to do wrong, for this may be said of the meanest of his subjects ; but it means that he cannot be accused or tried for any wrong before any criminal judica- ture. It is his prerogative, that he cannot be called to account for any wrong. 71, &c. — The doctrine deliveredfrom page 71 to 76, I suspect very much not to be just. If it be true, it is surely important, and would make many difficulties instantly to vanish, which the bulk of philosophers have laboured in vain to resolve, and the wiser part have reckoned to be insolvable. It is so new and so contrary to all that philosophers have taught and believed since the days of Aristotle, that it ought to be proposed and supported with great modesty ; but, indeed, I cannot yet assent to it. I have, for instance, the power of moving my hand ; all the activity I am conscious of exerting, is volition and effort to move the hand ; the motion must begin some- where. Suppose it begins at the nerves, and that its being continued till the hand be moved, is all mechanism. ' The first motion, however, cannot be mechanism. It follows immediately upon my volition and effort. Nor do I know how my volition and effort to move my hand, nroduoes a certain motion in the nerves. I am conscious that in this there is something which I do not comprehend, though I believe He that made me comprehends it perfectly. If I be struck with a palsy, that volition and effort which before moved my hand, is now unable to do it. Is this owing to an inability to produce the first motion ? or is it owing to some de- rangement of the machine of the body ? I know not. Nay, I am uncertain whether I be truly and properly the agent in the first motion ; for I can suppose, that, whenever I will to move my hand, the Deity, or some other agent, produces the first motion in my body — which was the opinion of Male- branche. This hypothesis agrees with all that I am conscious of in the matter. I am like a child turning the handle of a hand organ — the turning of the handle answers to my volition and effort. The music immediately follows ; but how it follows, the child knows not. Were two or three ingenious children to speculate upon the subject, who had never seen nor heard of such a machine before, perhaps one who had seen strange effects of mechanism, might conjecture that the handle, by means of machinery, produced the music : another, like Malebranche, might conjecture that a musician, concealed in the machine, always played when the handle was turned. We know as little how our intellectual operations are performed as how we move our own body. I remember many things past ; but how I remember them I know not. Some have attempted to account for memory by a repository of ideas, or by traces left in the brain of the ideas we had before. Such accounts would appear ridiculous at first sight, if we knew how the operation of memory is performed. But, as we are totally ignorant how we remember, such weak hypotheses have been embraced by sensible men. In these, and in innumerable cases that might be mentioned, it seems to me to be one thing to know that such a thing is, and another to know how it is. Perhaps you may have been led into the mistake, if it be a mistake, by what you say about definition in the note, p. 76. An operation, or any other thing that is per- fectly simple, cannot be defined — this is true. Nor can it be explained by words to a man who had not the conception of it be- fore ; for words can give us no new simple conceptions, but such only as we had before, and had annexed to such words. Thus, if a man born blind asks me what a scarlet colour is, the question, I think, is not impertinent, or nugatory, or absurd; but I can only answer him, that, though I know perfectly what a scarlet colour is, it is im- possible to give him a distinct conception of it unless he saw. But, if he asks me how LETTERS TO DR JAMES GREGORY. 81 my volition and effort moves ray hand, I not onely cannot satisfy him, but am con- scious that I am ignorant myself. We both know that there is a constant conjunction between the volition and the motion, when I am in health, but how they are connected I know not, but should think myself much wiser than I am, if I did know, for any- thing I know, some other being may move my hand as often as I will to move it. The volition, I am conscious, is my act ; but I am not conscious that the motion is so. I onely learn from experience that it always fol- lows the volition, when I am in sound health. Activity. — Sect. 1. P. 24, &c The distinction, between the two kinds of active verbs here marked, ap- pears no less clearly when they are used in the passive voice. To be known, to be be- lieved, &c, imply nothing done to the things known or believed. But to be wounded, to be healed, implies something done to the wounded or healed. A scholastick philoso- pher would say that to be wounded, belongs to the category of passion ; but to be knoun. belongs to none of the categories— being only an external denomination. Indeed, however grammarians might confound those two kinds of active verbs, the scholastick philo- sophers very properly distinguished the acts expressed by them. They called the acts expressed by the first kind immanent acts, and those expressed by the second kind, transitive acts. Immanent acts of mind are such as produce no change in the object. Such are all acts of understanding, and even sume that may be called voluntary— such as attention, deliberation, purpose. Activity — Sect. 2. P. 43. — If my memory does not deceive me, Charlevoix, in his history of Canada, says, that, in the Huron language, or in some language of that country, there is but one word for both the sexes of the human species, which word has two genders, not a mascu- line and feminine — for there is no such dis- tinction of genders in the language— but a a noble and an ignoble gender : the ignoble gender signifies not a woman, though we improperly translate it so. It signifies a coward, or a good-for-nothing creature of either sex. A woman of distinguished talents that create respect, is always of the noble gender. I know not whether it be owing to something of this kind in the Gaelic language, that a Highlander, who has got onely a little broken English, modestly takes the feminine gender to himself, and, in place of saying / did so, says, her own st/J did so. ..... . As to the mathematical reasoning on motive, Section 2, to prove that the relation of motive and agent is very different from that of a physical cause to its effect, I think it just and conclusive ; and that it is a good argument ad hominem, against the scheme of Necessity held by Hume, Priestley, and other modern advocates for Necessity, who plainly make these two relations the same. Mr Hume holds it for a maxim no less ap- plicable to intelligent beings and their ac- tions, than to. physical causes and their effects, that the cause is to be measured by the effect. And from this maxim he infers, or makes an Epicurean to infer, that we have reason to ascribe to the Deity just as much of wisdom, power, and goodness, as appears in the constitution of things, and no more. The reasoning in the papers on activity, to shew that the relation between an agent and his action is, in the structure of language, dis- tinguished from the relation between a cause and its effect, is, I think, perfectly just when cause is taken in a certain sense ; but I am not so clear that the word cause is never, except metaphorically or figuratively, taken in any other sense. You will see my senti- ments about that word in two chapters of my " Essay on the Liberty of Moral Agents," now in your hands. If I had seen your papers before I wrote those two chapters, perhaps I would have been more explicit. However, they will save you and me the trouble of repeating here what is there said. I think, after all, the difference between you and me is merely about the use of a word ; and that it amounts to this — whether the word cause, and the corresponding words in other languages, has, or has not, from the beginning, been used to express, without a figure, a being that produces the effect by his will and power. I see not how mankind could ever have acquired the conception of a cause, or of any relation, beyond a mere conjunction in time and place between it and its effect, if they were not conscious of active exertions in themselves, by which effects are pro- duced. This seems to me to be the origin of the idea or conception of production. In the grammar rule, causa, modus et instrumentum, &c, the word cause is taken in a limited sense, which is explained by the words conjoyned with it. Nor do I see that any part of the rule would be lost if the word causa had been altogether left out. Is not everything which you would call a cause a mean or an instrument ? May not everything to which the rule applies he called a mean or an instrument ? But surely many things are called causes that are a 82 CORRESPONDENCE OF DR REID. neither means nor instruments, and to which the rule does not apply. You know that Aristotle, who surely understood Greek, makes four kinds of causes — the efficient, the matter, the form, and the end- I thiiik the- grammar rule applies to none of these ; for they are not in Latin expressed by an oblative without a preposition. That nothing can happen without a cause, is a maxim found in Plato, in Cicero, and, I believe, never brought into doubt till the time of D. Hume. If this be not under- stood of an efficient cause, it is not true of any other kind of cause ; nor can any reason be given why it should have been universally received as an axiom. All other causes suppose an efficient cause ; but it supposes no other ; and, therefore, in every enumer- ation of causes, it is made the first ; and the word cause, without any addition, is put to signify an efficient cause ; as in that of Cicero, (which I quote only from memory,) " Itaque non est causa quod cuique ante~ ctdit, sed quod cuique efficicnter anle- eedil." XVIII. ON THE TERMS, PHILOSOPHICAL NECESSITY, AND NECESSARIAN — ON DETERMINATION BY STRONGEST MOTIVE — REPROACH OP MALA FIDES — CONSCIOUSNESS OF LIBERTY ARGUMENTUM PIGRUM,&C IN A PAPER ENTITLED — Remarks." Page 2. — " Philosophical Necessity." — This, I think, is an epithet given to the doctrine of Necessity by Dr Priestley only ; and I do not see that he deserves to be fol- lowed in it. The vulgar have, from the beginning of the world, had the conception of it as well as philosophers. Whether they ground it upon the influence of the stars, or the decrees of fate, or of the gods, or upon the influence of motives, it is necessity still. I have often found the illiterate vul- gar have recourse to it to exculpate their own faults, or those of their friends, when no other excuse could be found. It lurks in their minds as a last shift to alleviate the pangs of guilt, or to soften their indignation against those whom they love.-|- But it is not admitted on other occasions. Dr Priestley by this epithet no doubt wished it to pass for a profound discovery of philosophy ; but * On the " Essay " Somepages correspond to the published work, others do not. The " Essay ' was, therefore, probably printed but in proof. — H. + Thus Agamemnon :— 'Eyai 5' °ux uUtot tlm, 'AAA* Xtus xati Mo?g« Kx) rn^tKpotm 'h^lvvvs- — H. I know no claim it has to be called philoso. phical. In other places, you use another of Dr Priestley's words — the Necessarians. I see no reason for adding this word to our lan- guage, when Fatalists might do as well. Sometimes I think you call them the Philo- sophers indefinitely. I don't like this neither. Fatalism was never so general among philosophers, nor so peculiar to them, as to justify it. P. 27 In my " Essay on Liberty" I have censured the defenders of Necessity for grounding one of their chief arguments upon this as a self-evident axiom, That the strong- est motive always determines the agent, while no one of them, as far as I know, has offered to explain what is meant by the strongest motive, or given any test by which we may know which of two contrary motives is the strongest ; without which the axiom is an identical proposition, or has no meaning at all. I have offered two tests of the strength of motives — according as they operate upon the will immediately, or upon the under- standing — and endeavoured to shew that the maxim is not true according to either. P. 72. — The want of sincerity or bona fides, in a large body of men, respected and respectable, is a very tender place, and can- not be touched with too much delicacy. Though you were sure of being able to de- monstrate it, I am afraid it may be taken as an insult, which even demonstration cannot justify. Your not making the conclusion general, for want of a sufficiently extensive information, will not satisfy, because it seems to extend the conclusion as far as your observation has extended, and because the reasons on which you ground your con- clusion seem to extend it to all fatalists who can draw a conclusion from premises. If David Hume, or any other person, has charged those who profess to believe men to be free agents with insincerity, I think he did wrong, and that I should do wrong in following the example. But, setting apart the consideration of bienseance, I doubt of the truth of your conclusion. If human reason were perfect, I think you would be better founded ; but we are such imperfect creatures, that I fear we are not exempted from the possibility of swallowing contradictions. Could you not prove with equal strength that all bad men are infidels ? Yet I believe this not to be true. In page 76, you speak of our having a consciousness of independent activity. I think this cannot be said with strict pro- priety. It is only the operations of our own mind that we are conscious of. Ac- tivity is not an operation of mind ; it is a LETTERS TO DR JAMES GREGORY. «3 power to act. We are conscious of our volitions, but not of the cause of them. I think, indeed, that we have an early and a natural conviction that we have power to will this or that ; that this conviction precedes the exercise of reasoning ; that it is implyed in all our deliberations, purposes, promises, and voluntary actions: and I have used this as an argument for liberty. But I think this conviction is not properly called consciousness. I truly think that a fatalist who acted agreeably to his belief, would sit still, like a passenger in a ship, and suffer himself to be carried on by the tide of fate ; and that, when he deliberates, resolves, promises, or chuses, he acts inconsistently with his be- lief. But such inconsistencies, I fear, are to be found in life ; and, if men be ever con- vinced of them, it must be by soothing words and soft arguments, which ludunt cir- cum pnecordia ; for the force of prejudice, joyned with that of provocation, will shut the door against all conviction. I humbly think, therefore, that it will be prudent and becoming to express less con- fidence in your mathematical reasonings, though I really believe them to be just upon the hypothesis you combat. Fatalists will think that, when you put the issue of the controversy solely upon the experiments, you treat them like children. No fatalist will contend with you upon that footing, nor take it well to be challenged to do so ; and I think you have a good plea with any man who disputes the strength of your ma- thematical reasoning, to prove that the relation between motives and actions is altogether of a different kind, and subject to different laws from that between physical causes and their effects. XIX. ON VULGAR NOTION OP NECESSAEV CONNEC- TION INADVERTENCY OF HUME REID'S REPUTATION OF IDEAS — REIn'S USE OF THE WORD CAUSE —INERTIA, PASSIVITY, STATE, OP MIND AND SUNDRY OBSERVATIONS ON THE NECESSITARIAN CONTROVERSY IN A PAPER ENTITLED Remarks on the Essay. Page 23. — I am apt to think even the vulgar have the notion of necessary con- nection, and that they perceive it in arith- metical and mathematical axioms, though they do not speculate about it ; nor do they perceive it between physical causes and their effects. Does not every man of com- mon sense perceive the ridiculousness of ' Ae published.— H. that complaint to the gods, which one of the heroes of the " Dunciad" makes— " And am I now fourscore ? Ah! why, ye gods, should two and two make four t" But is it not remarkable that Mr Hume, after taking so much pains to prove that we have no idea of necessary connection, should impute to the bulk of mankind the opinion of a necessary connection between physical causes and their effects ? Can they have this opinion without an idea of necessary connection ? 33 — The passage here quoted from Mr Hume is, indeed, so extraordinary, that I suspect an error in printing, and that the word without has been put in against his intention, though I find it in my copy of his essays, as well as in your quotation. For how could a man who denies that we have any idea of necessary connection, defy any one to define a cause without comprehending necessary connection ? He might, consist- ently with himself, have defied any one to define a cause, comprehending in the defi- nition necessary connection ; and at the same time to shew distinctly the origin of the idea expressed by the definition. How could he pledge himself to give up the con- troversy on the condition of getting such a definition, when, as you observe, he had given two such definitions himself? If there be no error of the press, we must say, Aliquando bonus dormitat Humius. * 34 and 35. — You observe justly and perti- nently, that "the intelligible and consistent use of a word shews that the speaker had some thought, notion, or idea, correspond- ing to it." Idea is here put for the mean- ing of a word, which can neither be true nor false, because it implies neither affirmation nor negation. But in the same paragraph it is supposed that this idea may be im- proper, groundless, and to be given up. This can onely be applied to idea, taken in another sense — to wit, when it implies some affirmation or negation. I know this ambiguity may be found in Locke and Hume ; but I think it ought to be avoided. 36. — " Or the philosophical doctrine of ideas. " If, an hundred years after this, the philosophical doctrine of ideas be as little regarded as the Vortices of Des Cartes are at this day, they may then be coupled in the manner you here do. But at present, though I am proud of your opinion, that that doctrine must be given up, I think it is expressed in a way too assuming with regard to the publick. 40 I know of no philosopher who makes the word cause extend solely to the giving of existence. 44. Dr Reid agrees with the author of the Essay, that the word cause ought to be * See note at page 79.— H. g2 84 CORRESPONDENCE OF DR REID. used in the most common sense.* But one sense may be the most common in one science, and another in others. He thinks that, in theology and in metaphysicks, the most common sense is that of agent or efficient cause ; and for this he thinks he has the authority of Des Cartes, Locke, Dr Clarke, Bishop Butler, and many others. In physicks, and in all its branches, medi- cine, chymistry, agriculture, the mechani- cal arts, &c, he thinks the most common meaning of cause is Hume's notion of it — to wit, something which goes before the effect, and is conj oyned with it in the course of nature. As this notion is vague and popular, philosophers, when they would speak more precisely of a cause in physicks, mean by it some law of nature, of which the phseno- menon called the effect is a necessary consequence. Therefore, in writings of the former kind, he would think himself warranted to use the word cause, without addition in the first of these senses ; and, if he had occasion to use it in the last sense, he would call it physical cause. In writings of the last kind, he thinks it may, with pro- priety, be used without addition in the last sense -;' and if, in such writings, it be used in the first sense, he would have it called the efficient cause. But the additions of efficient and physical, he does [not] conceive as denoting two species of the same genus. * ThiB is in reference to what Dr Gregory says of trie meaning attached by Reid himself to the word cause. The passage is as follows : — ,( As little could he (Hume) have in view the meaning expressed in the third query, in which meaning Dr Reid (I own I think with too little regard to the common use and application of the word cause) hath employed it in arguing this question ; (* Essays on the Active Powers,' passim ; ) as where he says, after admitting that everything must have a cause, that, in the case of voluntary actions, it is not the motive, but the person, that is the cause of them. This meaning of the term cause — to wit, a being having power (and optional or discretionary powei) to produce or not to produce a certain change — is not only evidently dif- ferent from Mr Hume's, but completely repugnant to his whole system. We may therefore set it aside too." It is necessary to quote the queries to which refer, ence is made in the preceding passage. They are these: — " It might reasonably be asked — (1°) Is the word cause employed in that general fourfold sense mentioned by Aristotle, and applied equally to the essence or form of a being, to the matter of it, to the efficient or agent, and to the motive, or purpose, or final cause? Or (2°) is it employed in its more common and limited acceptation, as generally used in physics, and, indeed, in popular discourse, as when we say, ' Heat is the cause of expansion,' excluding all the other meanings of it, and particularly that of the agent? Or (3°) is it employed in that more limited sense in which it hath been defined and used by several philosophers, to denote exclusively theagent, in contradistinction to the physical cause? Or (4°) is it used to express the vague nation insinuated by Aristotle's ro e£ ov, comprehending all these already mentioned, and many more ? For example — what the parts are to the whole, what a right angle in a tri- angle is to the proportion between the squares of the sides of it, what the absence of a pilot is to a ship- wreck, what the seed is to a plant, what a father is to his son, what the removal of an opposing cause is to any event or effect, &c. Ike."— H, but as distinguishing two different meanings of the same ambiguous word. You have good reason to dispute the maxim about causes, as laid down by Mr Hume, in whatever sense he takes the word cause. It is a maxim in natural theology, universally admitted, that everything that begins to exist must have a cause, meaning an efficient cause ; and from this maxim we easily deduce the existance of a Being who neither had a cause nor a beginning of ex- istance, but exists necessarily. Physicks, in all its branches, is conversant about the phenomena of nature, and their physical causes ; and I think it may be admitted as a maxim that every phenomenon of nature has a physical cause. But the actions of men, or of other rational beings, are not phenomena of nature, nor do they come within the sphere of physicks. As little is a beginning of existance a phenomenon of nature. Page 154 — " Expressly excluding from the meaning of the phrase" fyc, to the end of the paragraph. * My remark upon this para- graph I ' think more important than any other I have made on the Essay; and, there- fore, I beg your attention to it. Inertia of mind seems to be a very pro- per name for a quality which, upon every system of Necessity, must belong to the mind. It is likewise very proper to explain the meaning of that term when applied to the mind. But when you " expressly exclude from the meaning of the phrase, the circumstance of mind remaining or persevering in any state into which it once gets," I wish you to consider very seriously whether this con- cession be not more generous than just ; and, if it be not just, whether by making it, you * The whole passage referred to is as follows :— *' I have occasion often to consider the supposed want of any such attribute of mind [viz., Power] as this is the fundamental principle of thedoctrine-ot necessity. And, for the sake of brevity, and the opposition to what has been often termed Activity and Force oj Mind, I call it the Inertia of Mind; limiting, how- ever, the signification of the phrase, to denote merely the incapacity of acting optionally or discretion ally without motives, or in opposition to all motives, or in any other way but just according to the motives applied, and expressly excluding from the meaning of the phrase the circumstance of mind remaining or persevering in any state into which it once gets, as body does in a state, either of rest or of uniform progressive rectilinear motion, into which it is once put. Such permanency of state does not appear to be any part of the constitution of the human mind, with respect to any of iis operations. Sensation of every kind— memory, imagination, judgment, emotion, or passion, volition, and involuntary effort — all appear to be transient conditions, or attributes of mind; which, of their own nature, independently of any cause applied, pass away or come to an end. And this I conceive to be one of the most general circum- stances of distinction between mere sta-eor condition, which is predicable ot mind as well as body, (as, for example, madness, idiotism, vivacity, dulness, pecu- liar genius, wisdom, knowledge, virtue, vice,) and those things which are termed acts or operations of mind or though i - ." — H LETTERS TO DR JAMES GREGORY. 85 do not much weaken the force of a great part of your. subsequent reasoning. The justice of the concession is not evi- dent to me. To be merely passive, and to remain in the stale into which it is put, seem to signify the same thing ; as, on the other hand, to be active, and to have power to change its own state, have the same meaning. If the mind be passive onely, all its changes are phenomena of nature, and therefore be- long to the science of physicks, and require a physical cause, no less than does the change of direction or of velocity in a moving body. Of all things that belong to the mind, its acts and operations are the onely things which have any analogy to motion in a body. The same analogy there is between the ceasing of any act or operation and the ceasing of motion. If, therefore, from mere inactivity, the body, once put in the state of motion, continues or perseveres in that state, why should not a mind, which is equally inactive, being once put in the state of action or operation, continue in that state ? You say, " Such permanency of state does not appear to be the constitution of the mind in any of its operations.". , I grant this. But the question is not, " What really is its constitution ?" but " What would be its constitution if it were as inert and in- active as body is ?" To admit this want of permanency is to admit that the mind is active in some degree, which is contrary to the supposition. The reason why madness, idiotism, &c, are called states of mind, while its acts and operationsarenot,* is because mankindhave always conceived the mind to be passive in the former and active in the later. But on the system of Necessity, this distinction has no place. Both are equally states, onely the first are not so frequently changed as the last. If the concession be just and consistent with necessity, it must be granted, what- ever be its consequences ; but I apprehend theconsequenceswilldeeply affect your essay. For, first, it contradicts what you have said, page 336, and, perhaps, in several other places, that, " according to Mr Hume's doctrine, a living person, in relation to motives and actions, is precisely in the situation of an inanimate body in relation to projection and gravity." If an inanimate body had not the quality of persevering in its state of motion, the effect of projection and gravity upon it would be very different from what it is with that quality. Secondly, by this concession, your reason- ing from the laws of motion and their cor- ollaries, is much weakened ; for those laws • The term State has, more especially of late years, and principally by Necessitarian philosophers, been applied to all modifications of mind indifferently. — H. and corollaries are founded on the supposi- tion that bodies persevere in the state of motion as well as of rest ; and, therefore, are not properly applied to a being which has not that quality. Indeed, perseverance in its state is so essential to inertia, that it will be thought unjustifiable to apply that name to what you acknowledge does not persevere in its state. And you will, perhaps, he charged with giving an invi- dious epithet to the mind, which, by your own acknowledgment, is not due, and then reasoning from that epithet as if it were due. 226— In the style of physicks, to carry a letter in the direction A B, and to carry a letter from A to the point B, are different things. Any line parallel to A B, is said to be in the direction A B, though it can- not lead to the point B. The case, therefore, here put, is, that the porter is offered a guinea a-mile to carry a letter from A to the point B, and half'-a- guinea a-mile to carry a letter, at the same time, from A to the point C. And both motives must necessarely operate according to their strength. I truely think it impos- sible to say how the porter would act upon these suppositions. He would be in an in- extricable puzzle between contrary actions and contrary wills. One should think that the two motives mentioned, would conjoyn their force in the diagonal. But, by going in the diagonal, he loses both the guineas and the half- guineas ; this is implied in the offer, and is a motive not to go in the diagonal, as strong as the two motives for going in it. By the force of the two motives, he must ivill to go in the diagonal ; by the force of the third, he must will not to go in the diagonal. You pretend to demonstrate that he must go in the diagonal willingly. I think it may be demonstrated, with equal force, that he must will not to go in the diagonal. I perceive no error in either demonstration ; and, if both demonstrations be good, what must be the conclusion ? The conclusion must be, that the supposition on which both demonstrations are grounded must be false — I mean the supposition that motives are the physical causes of actions ; for it is possible, and often happens, that, from a false sup- position, two contradictory conclusions may be drawn ; but, from a true supposition, it it impossible. I think it were better to omit the case stated toward the end of this page,* because I think it hardly possible to conceive two motives, which, being conjoyned, shall have an analogy to a projectile and centripetal force conjoyned ; and your concession, that * This has been done. — H. 86 CORRESPONDENCE OF DR REID. the effect of a motive is not permanent, adds to the difficulty. A projectile force requires a cause to begin it, but it requires no continuance of the cause — it continues by the inertia of matter. A centripetal force is the effect of a cause acting constantly ; and the effect of that cause must bear some proportion to the time it acts. Diminish the time, in infinitum, and the effect of a centripetal force is diminished, in infinitum ; so that, in any one instant of time, it bears no proportion to a projectile force ; and, what makes the effect of a centripetal, in a given time, to be capable of comparison with a projectile, force, is, that the effects of the centripetal force, during every instant of the time, are accumulated by the inertia of mat- ter, and all, as it were, brought into one sum. Now, how can you conceive two motives, which have a difference and a re- lation to each other, corresponding to the difference and the relation of these two kinds of force ? Both kinds of force suppose the permanency of motion once acquired, and, I think, cannot be distinctly conceived, or their effects ascertained, without that sup- position. 337- — Upon the scheme of Necessity, considered in this section, it must be main- tained, that there is some unknown cause or causes of human actions, besides motives, which sometimes oppose motives with greater force, sometimes produce actions without motives ; and, as there are no causes but physical causes, all actions must be neces- sary, whether produced by motives or by other physical causes. This scheme of Necessity appears, indeed, to me more tenable than that of H ume and Priestley ; and I wonder that Mr Hume, who thought that he had proved, beyond doubt, that we have no conception of any cause but a physi- cal cause, did not rest the doctrine of Neces- sity upon that principle solely. Unknown causes would have afforded him a retreat in all attacks upon his system. That motives are the sole causes of action, is onely an outwork in the system of Necessity, and may be given up, while it is maintained that every action must have a physical cause ; for physical causes of all human actions, whether they be known or unknown, are equally inconsist- ent with liberty. 342. — A physical cause, from its nature, must be constant in its effects, when it exists, and is applied to its proper object. But of un- known causes, the existence and the applica- tion may depend upon a concurrence of acci- dents, which is not subject to calculation, or even to rational conjecture. So that, I apprehend, the existance of such causes can never be demonstrated to be contrary to matter of fact. Unknown causes, like oc- cult qualities, suit every occasion, and can never be contradicted by phenomena ; for, as we cannot, a priori, determine what shall be the effects of causes absolutely unknown ; so it is impossible to prove, of any effect whatsoever, that it cannot be produced by some unknown physical cause or causes. The defects of this system of Necessity, I think, are these two :— first, it is a mere arbitrary hypothesis, brought to prop a weak side in the hypothesis of Necessity ; and, secondly, it is grounded on the supposition that every event must have a physical cause, a supposition which demonstrably termin- ates in an infinite series of physical causes, every one of which is the effect of a physical cause. If the doctrine opposed in this 16th sec- tion be as it is expressed, page 338 — that, though the connection of motive and action is but occasional, the volitions and actions of men are absolutely produced by motives as physical causes — this doctrine I take to be a contradiction in terms, and unworthy of confutation. It maintains that men are absolutely determined by motives, and yet onely occasionally determined by motives — which, if I understand it right, is a contra- diction. 351. The case supposed in this page seems perfectly similar to that of page 226 ; the same reasoning is applied to both- Should not the conclusion be the same in both ? 431. — Is there not some inaccuracy in the reasoning in this and the next page ? I take X and Y to represent equal motives to action, and V a motive to inaction, which equally opposes both. If this be so, the motives to the opposite action stand thus : X — V 4- Z on one side, and Y — V on the other. Then there will be a preponderancy on the side of X as long as X and its equal Y is greater than V ; and if X be withdrawn on one side, and Y on the other, we shall have — V -!- Z opposed to — V. In this case, if Z be equal to V, the motives to act and not to act on the side of Z will be equal ; if Z be less than V, the strongest motive will be for inaction ; and if Z be greater than V, there will be a preponderating motive to act on the side of Z As to the style in general, the only fault I find is, that it abounds too much in long and complex sentences, which have so many clauses, and so much meaning, that it is difficult to carry it all from the beginning to the end of the sentence. The reader's un- derstanding should have gentle exercise'but not hard labour, to comprehend the author's meaning. I dislike a style that is cut down into what the ancients called commas of a line or half a line. This, like water falling drop by drop, disposes one to sleep. But I think you rather go into the contrary ex- treme. Your friend, Lord Bacon, says, " A fiuent and luxuriant speech becomes youth well, but not age." I believe he had LETTERS TO DR JAMES GREGORY. «7 in his view a rhetorical speech, and not the lene et temperatum dicendi genus, which, in Cicero's judgment, best suits philosophy. XX. ON A NOVEL USB OP THE WORD MOTIVE — CAUSALITY OP MOTIVES, &C. 1793. Dear Sik — I received Mr Crombie's Essay* on Friday the 11th, at night, and have read it twice, though interrupted by the removal of my family to the college. If this be Mr Crombie's first essay in con- troversy, I third; he shews no mean talent, and may in time become an able champion. He has done me particular honour in directing so great a part of the book against me ; yet, though I read the work without prejudice, my opinion is not changed in any point of the controversy. He has strengthenedhis defensive armour by extending the meaning of the word mo- tive. I understood a motive, when applied to a human being, to be that for the sake of which f he acts, and, therefore, that what he never was conscious of, can no more be a motive to determine his will, than it can be an argument to convince his judgment. Now, I learn that any circumstance arising from habit, or some mechanical in- stinctive cause, may be a motive, though it never entered into the thought of the agent. From this reinforcement of motives, of which we are unconscious, every volition may be supplied with a motive, and even a predominant one, when it is wanted. Yet this addition to his defensive force takes just as much from his offensive. The chief argument for Necessity used by D. Hume and Lord Kames is, that, from experience, it appears that men are always determined by the strongest motive. This argument admits of much embellishment by a large and pleasant induction. * Dr Crombie, the well-known author of the " Gymnasium," and other able works, published an " Essay on Philosophical Necessity," London, 1793, in which Dr Gregory's reasoning is assailed with much acrimony and considerable acuteness. It is to this treatise that Reid's remarks apply. There subsequently appeared, " Letters .from Dr James Gregory of Edinburgh, in Defence of his lissay on the Difference ol'thc relation between Motiveand Action, and that of Cause and Effect in Physic* ; with Replies by the Rev. Alexander Crombie, LL.D.;" London, 1819. It is much to be regretted, that Dr Gregory did not find leisure to complete his " Answer to Messrs Crombie, Priestley, and Co. j" of which 512 pages have been printed, but are still unpublished. f This is Aristotle's definition (to 'inxu oZ) of end or final causr; and, as a synonyme for end or final cause, the term motive had been long exclusively employed. There are two schemes of Necessity — the Necessi'ation by efficient— the Necessitation by final causes The former is brute or blind Fate ; the latter rational Determinism. Though their practical results be the same, thev ought to be carefully dis- tinguished in theory.— H. After these two authors had exhausted their eloquence upon it, Mr Crombie adds his, from page 27 to 39. Now, if motives we are unconscious of be the cause of many actions, it will be impossible to prove from experience, that they are all caused by mo- tives. For no experiment can be made upon motives we are unconscious of. If, on the contrary, all our actions are found by experience to proceed from motives known or felt, there is no work left for the unknown, nor any evidence of their exist- ance. I apprehend, therefore, Mr Crombie must either keep by the old meaning of motive, or give up this argument for Neces- sity taken from experience. But helaysthemain stress, as Dr Priestley likewise has done, upon another argument. It is, that a volition not determined by mo- tives, is an uncaused effect, and therefore an absurdity, a contradiction, and the greatest of all absurdities. I think, indeed, it is in vain to reason upon the subject of Necessity pro or con, till this point be determined ; for, on the one side, to what purpose is[it] to disprove by argument a. proposition that is absurd ? On the other side, demonstration itself cannot prove that to be true which is absurd. If this be really an absurdity, Liberty must be given up. And if the appearance of absurdity be owing to false colouring, I think every argument this author has used, when weighed in the balance of reason, will be found light. I would, therefore, think it a prudent saving of time and labour, that controvertists on both sides should lay aside every other weapon, till the force of this be fairly tried. Mr Crombie triumphs in it almost in every page ; and I think Dr Priestley urged it as an apology for neglecting your essay, that you pretended to demonstrate an absurdity. It must, indeed, be granted, that even the Deity cannot give a power to man, which involves an absurdity. But if this absurdity vanish, when seen in a just light, then it will be time to examine the fact, whether such a power is given to man or not. Is a volition, undetermined by motives, an uncaused effect, and therefore an ab- surdity and a contradiction ? I grant that an uncaused effect is a con- tradiction in terms ; for an effect is some- thing effected, and what is effected implies an efficient, as an action implies an agent. To say an effect must have a cause, is really an identical proposition, which carries no information but of the meaning of a word. To say that an event — that is, a thing which began to exist — must have a cause, is not an identical proposition, and might have been as easily said. I know [no] reason why Mr Crombie should stick by this impro- priety, after it was censured in Dr Priestley, 88 CORRESPONDENCE OF DR REID. but that impropriety in the use of terms is an expedient either to cover an absurdity where it really is, or to make that appear absurd which is not so in reality. I grant, then, that an effect uncaused is a contradiction, and that an event uncaused is an absurdity. The question that remains is whether a volition, undetermined by mo- tives, is an event uncaused. This I deny. The cause of the volition is the man that willed it. This Mr Crombie grants in several places of his Essay — that the man is the efficient cause of all his volitions. Is it not strange, then, that, almost in every page, he should affirm that a volition, undeter- mined by motives, is an effect uncaused ? Is an efficient cause no cause ? or are two causes necessary to every event ?* Motives, he thinks, are not the efficient but the physi- cal cause of volitions, as gravity is of the descent of a stone. Then, fair dealing would have made him qualify the absurdity, and, say that it is absurd that a volition should be without a physical cause ; but to have pleaded the absurdity thus qualified, would have been a manifest petitio principii, I can see nothing in a physical cause but a constant conjunction with the effect. Mr Crombie calls it a necessary connection ; but this no man sees in physical causes ; and, if every event must have a physical cause, then every event must have been repeated in conjunction with its cause from eternity, for it could have no constant con- junction when first produced. The most shocking consequences of the system of necessity are avowed by this au- thor without shame. Moral evil is nothing but as it tends to produce natural evil. A man truely enlightened, ought to have no remorse for the blackest crimes. I think he might have added that the villain has reason to glory in his crimes, as he suffers for them without his fault, and for the com- mon good. Among the arts of this author, the following are often put in practice : — 1. To supply the defect of argument by abuse. 2. What he thinks a consequence of the system of Liberty he imputes to his adversaries as their opinion, though they deny it. 3. What is urged as a conse- quence of Necessity, he considers as imputing an opinion to those who hold Necessity, and thinks it answer that they hold no such opinion. 4. What is said to invalidate an argument for Necessity, he considers as an • This is no removal of the difficulty. Is the man determined to volition, and to a certain kind of voli- tion, or is he not? If the former, neccssitation is not avoided; if the latter, the admitted absurdity emerges. The schemes of Libenyand of Nece.-sityare contradictory ot each other: they consequently ex- elude any intermediate theory; and one or other must be true. Yet the possibility of neither can be conceived ; for each equally involves what is incom- prehensible, if not what is absurd. Hut ot this again, argument against Necessity ; and thinks it sufficient to shew that it does not answer a purpose for which it never was intended, aa if what is a sufficient answer to an argument for Necessity must be a conclusive argument against Necessity. I believe, however, he may claim the merit of adding the word Libertarian to the English language, as Priestley added that of Necessarian. — Yours, Tho. Reid.* XXL [The following Letter to Dr Gregory is quoted by Mr Stewart in his Cc Disserta- tion on the Progress of Metaphysical and Moral ScienceS* The dale is not given ; and the original is not now extant among the letters of Reid in the hands of Dr Gregory's family. — H. ] The merit of what you are pleased to call my philosophy, lies, I think, chiefly, in hav- ing called in question the common theory of ideas, or images of things in the mind, being the only objects of thought ; a theory founded on natural prejudices, and so uni- versally received as to be interwoven with the structure of the language. Yet, were I to give you a detail of what led me to call in question this theory, after I had long held it as self-evident and unquestionable, you would think, as I do, that there was much of chance in the matter. The discovery was the birth of time, not of genius ; and Berkeley and Hume did more to bring it to light than the man that hit upon it. I think there is hardly anything that can be called mine in the philosophy of the mind, which does not follow with ease from the detection of this prejudice. I must, there- fore, beg of you most earnestly to make no contrast in my favour to the disparagement of my predecessors in the same pursuits. I can truly say of them, and shall always avow, what you are pleased to say of me, that, but for the assistance I have received from their writings, I never could have wrote or thought what I have done. * Besides the preceding papers on the question of Liberty and Necessity, there are extant, Remarks at considerable length by Reid, on three sets of Objec. tions made by a distinguished natural philosopher to Dr Gregory's Essay, in the years 17S6, 1789, and 1790. These Kemarks, though of much interest, have been omitted : for they could not adequately be understood apart from the relative Objections; and these it was deemed improper to publish posthu- mously, after their author had expressly refused to allow them to be printed during his life. — There are also omitted, as of minor importance, two other papers on the same question ; the one containing, <* Remarks on the Objections to Dr Gregory's h ssay," which were printed in the appendix to that Essay ; theoth'r," Remarks"on apamphlet entitled " Illus- trations of Liberty and Necessity, in Answer to D» Gregory," published in 1795.— H. LETTERS TO THE REV. A. ALISON & PROFESSOR ROBISON. 89 D.— LETTER TO THE REV. ARCHIBALD ALISON. The following letter was addressed, by Dr Reid, to the Rev. Archibald Alison, (LL.B., Prebendary of Sarum, &c.,) on receiving a copy of his " Essays on the Nature and Principles of Taste" — a work of great ingenuity and elegance, and the first systematic attempt to explain the emotions of sublimity and beauty on the principles of association- It was originally published in 1790. It is, perhaps, needless to remind the reader that Mr Alison was brother-in-law of Dr Gregory. — H. ON THE PHILOSOPHY OP TASTE. Dear Sib, — I received your very oblig- ing letter of Jan. 10, with two copies of your book, about the middle of last week. I ex- pected a meeting of Faculty, to which I might present the book, and return you the thanks of the society along with my own ; but we have had no meeting since I received it. In the meantime, I have read it with avidity and with much pleasure ; and cannot longer forbear to return you my cordial thanks for this mark of your regard, and for the hand- some compliment you.make me in the book. I think your principles are just, and that you have sufficiently justified them by a great variety of illustrations, of which many appear new to me, and important in them- selves, as well as pertinent to the purpose for which they are adduced. That your doctrine concerning the sub- lime and beautiful in objects of sense coin- cides, in a great degree, with that of the Platonic school, and with Shaftesbury and Akenside among the moderns, I think may justly be said. They believed intellec- tual beauties to be the highest order, com- pared with which the terrestrial hardly de- serve the name. They taught beauty and good to be one and the same thing. But both Plato and those two, his admirers, handle the subject of beauty rather with the enthusiasm of poets or lovers, than with the cool temper of philosophers. And it is difficult to determine what allowance is to be made, in what they have said, for the hyperbolical language of enthusiasm. The other two you mention, Dr Hutche- son and Mr Spence, though both admirers of Plato, do not appear to me either to have perceived this doctrine in him, or to have discovered it themselves. The first places beauty in uniformity and variety, which, when they are perceived, immediately affect that internal sense which he calls the sense of beauty. The other makes colour, form, expression, and grace to be the four ingre- dients of beauty in the female part of our species, without being aware that the beauty of colour, form, and grace is nothing but expression, as well as what he calls by that name. On these grounds, I am proud to think that I first, in clear and explicit terms, and in the cool blood of a philosopher, main- tained that all the beauty and sublimity of objects of sense is derived from the expres- sion they exhibit of things intellectual, which alone have original beauty. But in this I may deceive myself, and cannot claim to be held an impartial judge. Though I don't expect to live to see the second part of your work, I have no hesi- tation in advising you to prosecute it ; being persuaded that criticism is reducible to prin- ciples of philosophy, which may be more fully unfolded than they have been, and which will always be found friendly to the best interests of mankind, as well as to manly and rational entertainment. Mrs Eeid desires to present her best re- spects to Mrs Alison, to which I beg you to add mine, and to believe me to be your much obliged and faithful servant, Tho. Reie. Glasgow College, 3d Feb. 1790. E,— LETTER TO PROFESSOR ROBISON. There has been given above, (p. 63,) a letter by Dr Reid, in 1784, recording a remarkable conversation between Sir Isaac Newton and Professor James Gregory, relative to Sir Isaac's descent from the family of Newton of Newton, in the county of East Lothian. Some years thereafter, Mr Barron, a relation of Sir Isaac, seems to have instituted inquiries in regard to the Scottish genealogy of the philosopher ; in con- 90 CORRESPONDENCE OF DR REID. sequence of which, the late Professor Robison of Edinburgh, aware, probably, of the letter to Dr Gregory, was induced to apply to Dr Reid for a more particular account of the conversation in question. The following is Reid's answer, as published in Sir David Brewster's " Life of Sir Isaac Newton." — H. Dear Sir,— I am very glad to learn, by yours of April 4, that a Mr Barron, a near relation of Sir Isaac Newton, is anxious to inquire into the descent of that great man, as the family cannot trace it farther, with any certainty, thanhisgrandfather. I there- fore, as you desire, send you a precise ac- count of all I know ; and am glad to have this opportunity, before I die, of putting this information in hands that will make the proper use of it, if it shall be found of any use. Several years before I left Aberdeen, (whichl didin 1764,)Mr Douglas of Fechel, the father of Sylvester Douglas, now a bar- rister at London, told me, that, having been lately at Edinburgh, he was often in com- pany of Mr Hepburn of Keith, a gentleman with whom I had some acquaintance, by his lodging a night at my house at NewMachar, when he was in the rebel army in 1745. That Mr Hepburn told him, that he had heard Mr James Gregory, Professor of Mathematics, Edinburgh, say, that, beiug one day in familiar conversation with Sir Isaac Newton at London, Sir Isaac said — " Gregory, I believe you don't know that I ama Scotchman." — " Pray, how is that ?" said Gregory. Sir Isaac said, he was in- formed that his grandfather (or great-grand- father) was a gentleman of East (or West) Lothian ; that he went to London with King James I. at his accession to the crown of England ; and that he attended the court, in expectation, as many others did, until he spent his fortune, by which means his family was reduced to low circumstances. At the time this was told me, Mr Gregory was dead, otherwise I should have had his own testimony ; for he was my mother's brother. I likewise thought at that time, that it had been certainly known that Sir Isaac had been descended from an old English family, as I think is said in his eloye before the Academy of Sciences at Paris; and therefore I never mentioned what I had heard for many years, believing that there must be some mistake in it. Some years after I came to Glasgow, I mentioned, (I believe for the first time,) what I had heard to have been said by Mr Hepburn, to Mr Cross, late sheriff of this county, whom you will remember. Mr Cross was moved by this account, and im- mediately said — " I know Mr Hepburn very well, and I know he was intimate with Mr Gregory. I shall write him this same night, to know whether he heard Mr Gregory say bo or not. " After some reflection, lie added — " I know that Mr Keith, the ambassador, was also an intimate acquaintance of Mr Gregory, and, as he is at present in Edin- burgh, I shall likewise write to him this night." The next time I waited on Mr Cross, he told me that he had wrote both to Mr Hepburn and Mr Keith, and had an answer from both ; and that both of them testified that they had several times heard Mr James Gregory say, that Sir Isaac New- ton told him what is above expressed, but that neither they nor Mr Gregory, as far as they knew, ever made any farther inquiry into the matter. This appeared very strange both to Mr Cross and me ; and he said he would reproach them for their indifference, and would make inquiry as soon as he was able. He lived but a short time after this ; and, in the last conversation I had with him upon the subject, he said, that all he had yet learned was, that there was a Sir John Newton of Newton in one of the counties of Lothian, (but I have forgot which,) some of whose children were yet alive ; that they reported that their father, Sir John, had a letter from Sir Isaac Newton, desiring to know the state of his family ; what children he had, particularly what sons ; and in what way they were. The old knight never re- turned an answer to this letter, thinking, probably, that Sir Isaac was some upstart, who wanted to claim a relation to his wor- shipful house. This omission the children regretted, conceiving that Sir Isaac might have had a view of doing something for then- benefit. After this, I mentioned occasionally in conversation what I knew, hoping that these facts might lead to some more certain dis- covery ; but I found more coldness about the matter than I thought it deserved. I wrote an account of it to Dr Gregory, your colleague, that he might impart it to any member of the Antiquarian Society who he judged might have had the curiosity to trace the matter farther. In the year 1787, my colleague, Mr Patrick Wilson, Professor of Astronomy, having been in London, told me, on bis return, that he had met accidentally with a James Hutton, Esq. of Pimlico, Westmin- ster, a near relation of Sir Isaac Newton, to whom he mentioned what he had heard from me with respect to Sir Isaac's descent, and that I wished much to know something decisive on the subject. Mr Hutton said, if I pleased to write to him, lie would give CORRESPONDENCE OF OR REID. 91 me all the information he could give. I wrote him, accordingly, and had a very polite answer, dated at Bath, 25th Decem- ber 1787, which is now before me. He says, " I shall be glad, when I return to London, if I can find, in some old notes of my mother, any thing that may fix the cer- tainty of Sir Isaac's descent. If he spoke so to Mr James Gregory, it is most cer- tain he spoke truth. But Sir Isaac's grandfather, not his great-grandfather, must be the person who came from Scot- land with King James I. If I find any thing to the purpose, I will take care it shall reach you." This is all I know of the matter; and for the facts above mentioned, I pledge my veracity. I am much obliged to you, dear Sii ,for the kind expressions of your affection and esteem, which, I assure you, are mutual on my part; and I sincerely sympathise with you on your afflicting state of health, which makes you consider yourself as out of the world, and despair of seeing me any more. I have been long out of the world by deafness and extreme old age. I hope, however, if we should not meet again in this world, that we shall meet and renew our acquaintance in another. In the meantime, I am, with great esteem, dear Sir, yours affectionately, Tho. Re in Glasgow College, 12tt April 1792. P.— LETTER TO DAVID HUME. The following is in answer to the letter of Hume, given by Mr Stewart in his Ac- count of Reid, (supra, p. 7, sq.) It is recently published, from the Hume papers, by Mr Burton, in his very able life of the philosopher ; and, though out of chrono- logical order, (by the reprinting of a leaf,) it is here inserted H. IN REFERENCE TO HIS OWN INQUIRY, PRIOR TO ITS PUBLICATION. King's College, [Aberdeen,] ISth March 1763. Sir, — On Monday last, Mr John Far- quhar brought me your letter of February 25th, enclosed in one from Dr Blair. I thought myself very happy in having the means of obtaining at second hand, through the friendship of Dr Blair, your opinion of my performance : and you have been pleased to communicate it directly in so polite and friendly a manner, as merits great acknowledgments on my part. Your keeping a watchful eye over my style, with a view to be of use to me, is an instance of candour and gene- rosity to an antagonist, which would affect me very sensibly, although I had no per- sonal concern in it, and I shall always be proud to show so amiable an example. Your judgment of the style, indeed, gives me great consolation, as I was very diffi- dent of myself in regard to English, and have been indebted to Drs Campbell and Gerard for many corrections of that kind. In attempting to throw some new light * Kant makes a similar acknowledgment. " By Hume," he says, " I was first Btartled out of my dogmatic slumber." Thus Hume (as elsewhere stated) is author, in a sort, of all our subsequent philosophy. For out of Reid and Kant, mediately or immediately, all our subsequent philosophy is upon those abstruse subjects, I wish to preserve the due mean betwixt confidence and despair. But whether I have any success in this attempt or not, I shall always avow myself your disciple in me- taphysics. I have learned more from your writings in this kind, than from all others put together. Your system appears to me not only coherent in all its parts, but likewise justly deduced from princi - pies commonly received among philoso- phers ; principles which I never thought of calling in question, until the conclu- sions you draw from them in the Treatise of Human Nature made me suspect them. If these principles are solid, your system must stand ; and whether they are or not, can better be judged after you have brought to light the whole system that grows out of them, than when the greater part of it was wrapped up in clouds and darkness. I agree with you, therefore, that if this system shall ever be de- molished, you have a just claim to a great share of the praise, both because you have made it a distinct and determined mark to be aimed at, and have furnished pro- per artillery for the purpose.* evolved; and the doctrines of Kant and Reid are both avowedly recoils from the annihilating scep- ticism of Hume — both attempts to find for philo- sophy deeper foundations than those which he had so thoroughly subverted — H. 92 CORRESPONDENCE OF DR REID. When you have seen the whole of my performance, I shall take it as a very great favour to have your opinion upon it, from which I make no doubt of re- ceiving light, whether I receive correc- tion or no. Your friendly adversaries Drs Campbell and Gerard, as well as Dr Gregory, return their compliments to you respectfully. A little philosophical so- ciety here, of which all the three are members, is much indebted to you for its entertainment. Your company would, although we are all good Christians, ba more acceptable than that of St Athana- sius ; and since we cannot have you upon the bench, you are brought oftener than any other man to the bar, accused and defended with great zeal, but without bitterness. If you write no more in morals, politics, or metaphysics, I am afraid we shall be at a loss for subjects. I am, respectfully, Sir, your most obliged, humble servant, Thomas Reid. The following should have been inserted in the correspondence with Karnes. Karnes's objection to Dr Adam Smith's theory of Sympathy as the sole foundation of our moral judgments, which appeared in the third edition of the " Essays on Morality," were, previously to publication, communicated to Dr Reid, who thus expresses his opinion on the subject : — ■ " I have always thought Dr S 's system of sympathy wrong. It is indeed only a refinement of the selfish system ; and I think your arguments against it are solid. But you have smitten with a friendly hand, which does not break the head ; and your compliment to the author I highly approve of. "—From Letter of 30th October 1778. In this judgment of Smith, Reid and Kant are at one. The latter condemns the Ethic of Sympathy as a Eudsemonism, or rather Hedonism H. In Hutton's Mathematical Dictionary, 1795, in the article, David Gregorv> there are given, " Some farther particulars of the families of Gregory and Ander- son, communicated by Dr Thomas Reid," &c, probably written in the year of publication, or the preceding. As these notices contain nothing of any moment which does not appear in the foregoing correspondence, it has been deemed unnecessary to reprint them. — H. AN INQUIRY INTO THE HUMAN MIND, ON THE PRINCIPLES OP COMMON SENSE. ByTHOMAS reid, d.d, rROFESSOR OP MORAL PHILOSOPHY IN THE UNIVERSITY OF GLASGOW. " The inspiration of the Almighty giveth them understanding."— Job. 03- This Inquiry was first published in 1764, when Dr Reid was Professor of Philo- sophy, in King's College, Aberdeen. Three subsequent editions were printed daring the author's lifetime — in 1765, 1769, and 1785. The text of the present impression is taken from the last authentic edition — the fourth, or that of 1785, which professes to be " corrected;" collated, however, with the first, and any variations of importance noticed. — H. DEDICATION. THE RIGHT HONOURABLE JAMES, EARL OF FINDLATER AND SEAFIELD,* CHANCELLOR OP THE UNIVERSITY OP OLD ABERDEEN. My Lord, — Though I apprehend that there are things new and of some import- ance, in the following Inquiry, it is not without timidity that I have consented to the publication of it. The subject has been canvassed by men of very great penetration and genius : for who does not acknowledge Des Cartes, Malebranche, Locke, Berkeley, and Hume, to be such ? A view of the human understanding, so different from that which they have exhibited, will, no doubt, be condemned by many, without examin- ation, as proceeding from temerity and vanity. But I hope the candid and discerning Few, who are capable of attending to the opera- tions of their own minds, will weigh delibe- rately what is here advanced, before they pass sentence upon it. To such I appeal, as the only competent judges. If they dis- approve, I am probably in the wrong, and shall be ready to change my opinion upon conviction. If they approve, the Many will at last yield to their authority, as they always do. However contrary my notions are to those of the writers I have mentioned, their spe- culations have been of great use to me, and seem even to point out the road which I have taken : and your Lordship knows, that the merit of useful discoveries is sometimes not more justly due to those that have hit upon them, than to others that have ripened them, and brought them to the birth. I acknowledge, my Lord, that I never thought of calling in question the principles commonly received with regard to the hu- man understanding, until the " Treatise of Human Nature" was published in the year 1 739. The ingenious author of that treatise upon the principles of Locke — who was no * In the first edition, "James Lord Deskfoord"— his fader being still alive.— H. sceptic — hath built a system of scepticism, which leaves no ground to believe any one thing rather than its contrary. His reason- ing appeared to me to be just ; there was,„ therefore, a necessity to call in question the* principles upon which it was founded, or to admit the conclusion. * But can any ingenuous mind admit this sceptical system without reluctance ? I truly could not, my Lord ; for I am per- suaded, that absolute scepticism is not more destructive of the faith of a Christian than of the science of a philosopher, and of the prudence of a man of common understand- ing. I am persuaded, that the unjust live by faith-f as well as the just ,- that, if all belief could be laid aside, piety, patriotism, friendship, parental affection, and private virtue, would appear as ridiculous as knight- errantry ; and that the pursuits of pleasure, of ambition, and of avarice, must be grounded upon belief, as well as those that are honourable or virtuous. The dayJabourer toils at his work, in the belief that he shall receive his wages at night ; and, if he had not this belief, he would not toil. We may venture to say, that even the author of this sceptical system wrote it in the belief that it * "This doctrine of Ideas,"(says Dr*Reid,in a sub. sequent work,) " I once believed so firmly, as to em- brace the whole of Berkeley's system in consequence of it ; till, finding other consequences to follow from it, which gave me more uneasiness than the want of a material world, it came into my mind, more than forty years ago, to put the question, What evidence have I for this doctrine, that all the olijects of my knowledge are ideas in my own mind?" — Essays on the Intellectual Powers, Ess. 11. ch. x. p. 1G-2. In like manner, Kant informs us, that it was by Hume's sceptical inferences, in regard to the causal nexus, that he also " was first roused from his dog. matic slumber." See the "Prolegomena," p. 13.— H. t See Note A at the end of the volume, in illustra- tion of the principle, that the root of Knowledge is Belief.— H. 9(5 OF THE HUMAN MIND. should be read and regarded. I hope he wrote it in the belief also that it would be useful to mankind ; and, perhaps, it may prove so at last. For I conceive the scep- tical writers to be a set of men whose busi- ness it is to pick holes in the fabric of knowledge wherever it is weak and faulty ; and, when these places are properly repaired, the whole building becomes more firm and solid than it was formerly. For my own satisfaction, I entered into a serious examination of the principles upon which this sceptical system is built ; and was not a little surprised to find, that it leans with its whole weight upon a hypo- thesis, which is ancient indeed, and hath been very generally received by philoso- phers, but of which I could find no solid proof. The hypothesis I mean, is, That Jiothing is perceived but what is in the mind which perceives it : That we do not really perceive things that are external, but only certain images and pictures of them imprinted upon the mind, which are called impressions and ideas- It this be true, supposing certain im- pressions and ideas to exist in my mind,* I cannot, from their existence, infer the exist- ence of anything else : my impressions and ideas are the only existences of which I can have any knowledge or conception ; and they are such fleeting and transitory beings, that they can have no existence at all, any longer than I am conscious of them. So that, upon this hypothesis, the whole uni- verse about me, bodies and spirits, sun, moon, stars, and earth, friends and rela- tions, all things without exception, which I imagined to have a permanent existence, whether I thought of them or not, vanish at once ; " And, like the baseless fabric of a vision, Leave not a track behind." I thought it unreasonable, my Lord, upon the authority of philosophers, to admit a hypothesis which, in my opinion, overturns all philosophy, all religion and virtue, and all common sensef — and, finding that all the systems concerning the human understand- ing which I was acquainted with, were built upon this hypothesis, I resolved to inquire into this subject anew, without regard to any hypothesis. What I now humbly present to your Lordship, is the fruit of this inquiry, so far only as it regards the five senses : in which I claim no other merit than that of having * In first edition, " to exist presently in my mind." I may here, once for all, notice that pre- sently, (in its original and proper sense, and as it is frequently employed by Reid,) for now or at present, has waxed obsolete in English. For above a century ami a half, it is only to be found in good English writers in the secondary meaning of in a little while — without delay- — H. + See Note A at the end of the volume, in defence and illustration of the term Common Sense.— H. given great attention to the operations of my own mind, and of having expressed, with all the perspicuity I was able, what I conceive every man, who gives the same attention, will feel and perceive. The productions of imagination require a genius which soars above the common rank ; but the treasures of knowledge are commonly buried deep, and may be reached by those drudges who can dig with labour and patience, though they have not wings to fly. The experi- ments that were to be made in this investi- gation suited me, as they required no other expense but that of time and attention, which I could bestow. The leisure of an academical life, disengaged from the pur- suits of interest and ambition ; the duty of my profession, which obliged me to give prelections on these subjects to the youth ; and an early inclination to speculations of this kind, have enabled me, as I flatter my- self, to give a more minute attention to the subject of this inquiry, than has been given before. My thoughts upon this subject were, a good many years ago, put together in an- other form, for the use of my pupils, and afterwards were submitted to the judgment of a private philosophical society," of which I have the honour to be a member. A great part of this Inquiry was honoured even by your Lordship's perusal. And the encouragement which you, my Lord, and others, whose friendship is my boast, and whose judgment I reverence, were pleased to give me, counterbalance my timi- dity and diffidence, and determined me to offer it to the public. If it appears to your Lordship to justify the common sense and reason of mankind, against the sceptical subtilties which, in this age, have endeavoured to put them out of countenance — if it appears to throw any new light upon one of the noblest parts of the divine workmanship — your Lordship's respect for the arts and sciences, and your attention to everything which tends to the improvement of them, as well as to every- thing else that contributes to the felicity of your country, leave me no room to doubt of your favourable acceptance of this essay, as the fruit of my industry in a profession+ wherein I was* accountable to your Lord- ship ; and as a testimony of the great esteem and respect wherewith I have the honour to be, My Lord, Your Lordship's most obliged And most devoted Servant, Tho. Eeid.§ * See above, p 4i,b.— H. t Reid, here and elsewhere, uses profession for chat*- or professorship. — H. t " Am" — first edition — H. f ; In first edition this dedication is dated — " King's College, Nov. 9, 1763."— H. AN INQUIRY INTO THE HUMAN MIND. CHAPTER I. INTRODUCTION. Section I. THE IMPORTANCE OF THE SUBJECT, AND THE MEANS OP PROSECUTING IT. '1 he fabric of the human mind is curious ; nd wonderful, as well as that of the human body. The faculties of the one are with no less wisdom adapted to their several ends than the organs of the other. Nay, it is reasonable to think, that, as the mind is a nobler work and of a higher order than the body, even more of the wisdom and skill o_ the divine Architect hath been employed in its structure. It is, therefore, a subject highly worthy of inquiry on its own account, but still more worthy on account of the extensive influence which the knowledge of it hath over every other branch of science. In the arts and sciences which have least connection with the mind, its faculties are the engines which we must employ; and the better we understand their nature and use, their defects and disorders, the more skilfully we shall apply them, and with the greater success. But in the noblest arts, the mind is also the subject" upon which we operate. The painter, the poet, the actor, the orator, the moralist, and the statesman, attempt to operate upon the mind in differ- ent ways, and for different ends ; and they succeed according as they touch properly the strings of the human frame. Nor can * In philosophical language, it were to be wished that the word subject should be reserved for the sub- ject of inhesi n — the materia in gun ; and the term vbjeci exclusively applied to the subject of operation — the materia circa quam. If this be not done, the grand distinction of subjective and objective, in phi. losophy, is confounded. But if the employment of Subject for Object is to be deprecated, the employ- ment of Object for purpose or final cause, (in th° French and English languages,) is to be absolutely condemned, as a recent and irrational confusion ot notions which should lie carefully distinguished.— H. their several arts ever stand on a solid found- ation, or rise to the dignity of science, until they are built on the principles of the human constitution. Wise men now agree, or ought to agree, in this, that there is but one way to the knowledge of nature's works — the way of observation and experiment. By our con- stitution, we have a strong propensity to trace particular facts and observations to general rules, and to apply such general rules to account for other effects, or to direct us in the production of them. This proce- dure of the understanding is familiar to every human creature in the common affairs of life, and it is the only one by which any real discovery in philosophy can be made. The man who first discovered that cold freezes water, and that heat turns it into vapour, proceeded on the same general prin. ciples, and in the same method by which Newton discovered the law of gravitation and the properties of light. His reguta vhilosophandi are maxims of common sense, and are practised every day in common life ; and he who philosophizes by other rules, either concerning the material sys- tem or concerning the mind, mistakes his aim. Conjectures and theories' are the crea- tures of men, and will always be found very unlike the creatures of God. If we would know the works of God, we must consult themselves with attention and humility, without daring to add anything of ours to what they declare. A just interpretation of nature is the only sound and orthodox philosophy : whatever we add of our own, is apocryphal, and of no authority. All our curious theories of the formation of the earth, of the generation of animals, of the origin of natural and moral evil, so far as they go beyond a just induction from » Reid uses the terms, Theory, Hypothesis, and Conjecture, as convertible, and always in an unfavour. able acceptation. Herein there is a double inaccu- racy. But of this again.— H. 98 OF THE HUMAN MIND. facts, are vanity and folly, no less than the Vortices of Des Cartes,* or the Archseus of Paracelsus. Perhaps the philosophy of the mind hath been no less adulterated by theories, than that of the material system. The theory of Ideas is indeed very ancient, and hath been very universally received ; but, as neither of these titles can give it authenticity, they ought not to screen it from a free and candid examination ; especially in this age, when it hath produced a system of scepticism that seems to triumph over all science, and even over the dictates of com- mon sense. All that we know of the body, is owing to anatomical dissection and observation, and it must be by an anatomy of the mind that we can discover its powers and prin- ciples. Section II. THE IMPEDIMENTS TO OUR KNOWLEDGE OF THE MIND. But it must be acknowledged, that this kind of anatomy is much more difficult than the other ; and, therefore, it needs not seem strange that mankind have made less progress in it. To attend accurately to the operations of our minds, and make them an object of thought, is no easy mat- ter even to the contemplative, and to the bulk of mankind is next to impossible. An anatomist who hath happy opportu- nities, may have access to examine with his own eyes, and with equal accuracy, bodies of all different ages, sexes, and conditions ; so that what is defective, ob- scure, or preternatural in one, may be discerned clearly and in its most perfect state in another. But the anatomist of the mind cannot have the same advantage. It is his own mind only that he can examine with any degree of accuracy and distinct- ness. This is the only subject he can look into. He may, from outward signs, collect the operations of other minds; but these signs are for the most part ambiguous, and must be interpreted by what he perceives within himself. So that, if a philosopher could delineate to us, distinctly and methodically, all the operations of the thinking principle within him, which no man was ever able to do, this would be only the anatomy of one par- ticular subject ; which would be both defi- cient and erroneous, if applied to human nature in general. For a little reflection * No one deemed more lightly of his hypotheses than Des Cartes himself He called them " philosoph- ical romances ;" and thus anticipated Father Daniel, who again anticipated Voltaire, in the saying — The Philosophy of Des Cartes is the Romance of Nature. ™-H, may satisfy us, that the difference of minds is greater than that of any other beings which we consider as of the same species. Of the various powers and faculties we possess, there are some which nature seems both to have planted and reared, so as to have left nothing to human industry. Such are the powers which we have in common with the brutes, and which are necessary to the preservation of the individual, or the continuance of the kind. There are other powers, of which nature hath only planted the seeds in our minds, but hath left the rearing of them to human culture. It is by the proper culture of these that we are cap- able of all those improvements in intellec- tuals, in taste, and in morals, which exalt and dignify human nature ; while, on the other hand, the neglect or perversion of them makes its degeneracy and corruption. The two-legged animal that eats of na- ture's dainties, what his taste or appetite craves, and satisfies his thirst at the crystal fountain, who propagates his kind as occa- sion and lust prompt, repels injuries, and takes alternate labour and repose, is, like a tree in the forest, purely of nature's growth. But this same savage hath within him the seeds of the logician, the man of taste and breeding, the orator, the statesman, the man of virtue, and the saint ; which seeds, though planted in his mind by nature, yet, through want of culture and exercise, must lie for ever buried, and be hardly perceivable by himself or by others. The lowest degree of social life will bring to light some of those principles which lay hid in the savage state ; and, according to his training, and company, and manner of life, some of them, either by their native vigour, or by the force of culture, will thrive and grow up to great perfection, others will be strangely perverted from their natural form, and others checked, or perhaps quite eradicated. This makes human nature so various and multiform in the individuals that partake of it, that, in point of morals and intellectual endowments, it fills up all that gap which we conceive to be between brutes and devils below, and the celestial orders above ; and such a prodigious diversity of minds must make it extremely difficult to discover the common principles of the species. The language of philosophers, with re- gard to the original faculties of the mind, is so adapted to the prevailing system, that it cannot fit any other ; like a coat that fits the man for whom it was made, and shews him to advantage, which yet will sit very awkward upon one of a different make, although perhaps as handsome and as well proportioned. It is hardly possible to make any innovation in our philosophy concern- ing the mind and its operations, without INTRODUCTION". 99 asing new words and phrases, or giving a different meaning to those that are received — a liberty which, even when necessary, creates prejudice and misconstruction, and which must wait the sanction of time to authorize it ; for innovations in language, like those in religion and government, are always suspected and disliked by the many, till use hath made them familiar, and pre- scription hath given them a title. If the original perceptions and notions' of the mind were to make their appearance single and unmixed, as we first received them from the hand of nature, one accus- tomed to reflection would have less difficulty iii tracing them ; but before we are capa- ble of reflection, they are so mixed, com- pounded, and decompounded, by habits, associations, and abstractions, that it is hard to know what they were originally. The mind may, in this respect, be compared to an apothecary or a chemist, whose mate- rials indeed are furnished by nature ; but, for the purposes of his art, he mixes, com- pounds, dissolves, evaporates, and sublimes them, till they put on a quite different appearance ; so that it is very difficult to know what they were at first, and much more to bring them back to their original and natural form. And this work of the mind is not carried on by deliberate acts of mature reason, which we might recollect, but by means of instincts, habits, associa- tions, and other principles, which operate before we come to the use of reason ; so that it is extremely difficult for the mind to return upon its own footsteps, and trace back those operations which have employed it since it first began to think and to act. Could we obtain a distinct and full his- tory of all that hath past in the mind of a child, from the beginning of life and sensa- tion, till it grows up to the use of reason — how its infant faculties began to work, and how they brought forth and ripened all the various notions, opinions, and sentiments which we find in ourselves when we come to be capable of reflection — this would be a treasure of natural history, which would probably give more light into the human faculties, than all the systems of philoso- phers about them since the beginning of the world. But it is in vain to wish for what nature has not put within the reach of our power. Reflection, the only instru- ment by which we can discern the powers of the mind, comes too late to observe the progress of nature, in raising them from their infancy to perfection. It must therefore require great caution, and great application of mind, for a man that is grown up in all the prejudices of education, fashion, and philosophy, to unravel his notions and opinions, till he find out the simple and original principles of his constitution, of which no account can be given but the will of our Maker. This may be truly called an analysis of the human faculties ; and, till this is performed, it is in vain we expect any juBt system of the mind — that is, an enumeration of the original powers and laws of our constitution, and an explication from them of the various phenomena of human nature. Success in an inquiry of this kind, it is not in human power to command ; but, per- haps, it is possible, by caution and humility, to avoid error and delusion. The labyrinth may be too intricate, and the thread too fine, to be traced through all its windings ; but, if we stop where we can trace it no farther, and secure the ground we have gained, there is no harm done ; a quicker eye may in time trace it farther. It is genius, and not the want of it, that adulterates philosophy, and fills it with error and false theory. A creative imagi- nation disdains the mean offices of digging for a foundation, of removing rubbish, and carrying materials ; leaving these servile employments to the drudges in science, it plans a design, and raises a fabric. Inven- tion supplies materials where they are wanting, and fancy adds colouring and every befitting ornament. The work pleases the eye, and wants nothing but solidity and a good foundation. It seems even to vie with the works of nature, till some succeeding architect blows it into rubbish, and builds as goodly a fabric of his own in its place. Happily for the pre- sent age, *the castle-builders employ them- selves more in romance thau in philosophy. That is undoubtedly their province, and in those regions the offspring of fancy is legitimate, but in philosophy it is all spu- rious." Section III. THE PRESENT STATE OP THIS PART OF PHILO- SOPHY — OF nES CARTES, MALEBRANCHE, AND LOCKE. That our philosophy concerning the mind and its faculties is but in a very low state, may be reasonably conjectured even by those who never have narrowly examined it. Are there any principles, with regard to the mind, settled with that perspicuity and evidence which attends the principles of mechanics, astronomy, and optics ? These are really sciences built upon laws of nature which universally obtain. What is * The same doctrine of the incompatibility of crea- tive imagination and philosophical talent, is held by Hume and Kant. There is required, however, foi the metaphysician, not less imagination than for the poet, though of a different kind j it may, in fact, lie doubted whether Homer or Aristotle possessed this faculty in greater vigour. — H. H2 100 OF THE HUMAN MIND. discovered in them is no longer matter of dispute : future ages may add to it ; but, till the course of nature be changed, what is already established can never be overturned. But when we turn our attention inward, and consider the phaenomena of human thoughts, opinions, and perceptions, and endeavour to trace them to the general laws and the first principles of our constitution, we are imme- diately involved in darkness and perplexity ; and, if common sense, or the principles of education, happen not to be stubborn, it is odds but we end in absolute scepticism. Des Cartes, finding nothing established in this part of philosophy, in ortler to lay the foundation of it deep, resolved not to believe his own existence till he should be able to give a good reason for it. He was, per- haps, the first that took up such a resolu- tion ; but, if he could indeed have effected his purpose, and really become diffident of his existence, his case would have been deplorable, and without any remedy from reason or philosophy. A man that dis- believes his own existence, is surely as unfit to be reasoned with as a man that believes he is made of glass. There may be dis- orders in the human frame that may pro- duce such extravagancies, but they will never be cured by reasoning. Des Cartes, in- deed, would make us believe that he got out of this delirium by this logical argument, Cogito, ergo sum ; but it is evident he was in his senses all the time, and never seri- ously doubted of his existence ; for he takes it for granted in this argument, and proves nothing at all. I am thinking, says he — therefore, I am. And is it not as good rea- soning to say, I am sleeping — therefore, I am ? or, I am doing nothing — therefore, I am ? If a body moves, it must exist, no doubt ; but, if it is at rest, it must exist likewise. " Perhaps Des Cartes meant not to assume his own existence in this enthymeme, but the existence of thought ; and to infer from that the existence of a mind, or subject of thought. But why did he not prove the existence of his thought ? Consciousness, it may be said, vouches that. But who is voucher for consciousness ? Can any man prove that his consciousness may not deceive him ? No man can ; nor can we give a better reason for trusting to it, than that every man, while his mind is sound, is determined, by the constitution of his na- ture, to give implicit belief to it, and to laugh at or pity the man who doubts its testimony. And is not every man, in his wits, as much determined to take his exist- ence upon trust as his consciousness ? * The nature of the Cartesian Doubt and its solu- tion is here misapprehended — how, will be shewn in a note upon the eighth chapter of the second" riss.iy 3n the In'ellectual Powers." — H. The other proposition assumed in this argument, That thought cannot be without a mind or subject, is liable to the same objection : not that it wants evidence, but that its evidence is no clearer, ner more immediate, than that of the proposition to be proved by it. And, taking all these pro positions together — I think ; I am con- scious ; Everything that thinks, exists ; I exist — would not every sober man form the same opinion of the man who seriously doubted any one of them ? And if he was his friend, would he not hope for his cure from physic and good regimen, rather than from metaphysic and logic ? But supposing it proved, that my thought and my consciousness must have a subject, and consequently that I exist, how do I know that all that train and succession of thoughts which I remember belong to one subject, and that the I " of this moment is the very individual I of yesterday and of times past ? Des Cartes did not think proper to start this doubt ; but Locke has done it ; and, in order to resolve it, gravely determines that personal identity consists in consciousness — that is, if you are conscious that you did such a thing a twelvemonth ago, this con- sciousness makes you to be the very person that did it. Now, consciousness of what is past can signify nothing else but the re- membrance that I did it ; so that Locke's principle must be, That identity consists in remembrance ; and, consequently, a man must lose his personal identity with regard to everything he forgets. Nor are these the only instances whereby our philosophy concerning the mind appears to be very fruitful in creating doubts, but very unhappy in resolving them. Des Cartes, Malebranche, and Locke, have all employed their genius and skill to prove the existence of a material world ; and with very bad success. Poor untaught mortals believe undoubtedly that there is a sun, moon, and stars ; an earth, which we inhabit ; country, friends, and relations, which we enjoy ; land, houses, and move- ables, which we possess. But philosophers, pitying the credulity of the vulgar, resolve to have no faith but what is founded upon reason. + They apply to philosophy to fur- * In English, we cannot say the I, and the Not.l so happily as the Fr< nch le Mor, and le Non-Moi, or even the Germans das Ich, and das Nicht-lch. llie ambiguity arising from the identity of sound between the I and Hie eye, would of itself preclude the ordinary employment ot the former. 1 tie Ego and Ihc Non- Ego are the best terms we can u-e ; and, as the ex. pressions are scientific, i t is perhaps no loss that their technical precision Is guarded by their non-vernacul- arity.— H. + Reason is here employed, by Reid, not as a synonyme for Common Sense, (vove, locus princi- piorum,) and as he himself more correctly emplo\s it in his later works, but as equivalent to Reason- ing, ( 5i«vo<«, discur-us mmtalis.) See Note *.— li. INTRODUCTION. 101 nish them with reasons for the belief of those things which all mankind have be- lieved, without being able to give any rea- son for it. And surely one would expect, that, in matters of such importance, the proof would not be difficult : but it is the most difficult thing in the world. For these three great men, with the best good will, have not been able, from all the treasures of philosophy, to draw one argument that is fit to convince a man that can reason, of the existence of any one thing without him. Admired Philosophy ! daughter of light ! parent of wisdom and knowledge ! if thou art she, surely thou hast not yet arisen upon the human mind, nor blessed us with more of thy rays than are sufficient to shed a darkness visible upon the human facul- ties, and to disturb that repose and security which happier mortals enjoy, who never approached thine altar, nor felt thine in- flueuce ! But if, indeed, thou hast not power to dispel those clouds and phantoms which thou hast discovered or created, with- draw this penurious and malignant ray ; I despise Philosophy, and renounce its guid- ance — let my soul dwell with Common Sense.* Section IF. APOLOGY FOR THOSE PHILOSOPHERS. But, instead of despising the dawn of light, we ought rather to hope for its increase : instead of blaming the philosophers I have mentioned for the defects and blemishes of their sj'stem, we ought rather to honour their memories, as the first discoverers of a region in philosophy formerly unknown ; and, however lame and imperfect the sys- tem may be, they have opened the way to future discoveries, and are justly entitled to a great share in the merit of them. They have removed an infinite deal of dust and rubbish, collected in the ages of scholastic sophistry, which had obstructed the way. They have put us in the right road — that of experience and accurate reflection. They have taught us to avoid the snares of am- biguous and ill-defined words, and have spoken and thought upon this subject with a distinctness and perspicuity formerly un- known. They have made many openings that may lead to the discovery of truths which they did not reach, or to the detec- tion of errors in which they were involun- tarily entangled. It may be observed, that the defects and blemishes in the received philosophy con- cerning the mind, which have most exposed • Mr Stewart very justly censures the vagueness and amlnguity of this passage, Elem. vol. ii., cb. i., \ 3, p. 92, 8vo editions.— H. it to the contempt and ridicule of sensible men, have chiefly been owing to this — that the votaries of this Philosophy, from a na- tural prejudice in her favour, have endea- voured to extend her jurisdiction beyond its just limits, and to call to her bar the dictates of Common Sense. But these decline this jurisdiction ; they disdain the trial of rea- soning, and disown its authority ; they neither claim its aid, nor dread its attacks. In this unequal contest betwixt Common Sense and Philosophy, the latter will always come off both with dishonour and loss ; not can she ever thrive till this rivalship is dropt, these encroachments given up, and a cordial friendship restored : for, in reality, Common Sense holds nothing of Philoso- phy, nor needs her aid. But, on the other hand, Philosophy (if I may be permitted to change the metaphor) has no other root but the principles of Common Sense ; it grows out of them, and draws its nourishment from them. Severed from this root, its honours wither, its sap is dried up, it dies and rots. The philosophers of the last age, whom I have mentioned, did not attend to the pre- serving this union and subordination so carefully as the honour and interest of phi- losophy required : but those of the present have waged open war with Common Sense, and hope to make a complete conquest of it by the subtilties of Philosophy — an attempt no less audacious and vain than that of the giants to dethrone almighty Jove. Section V. OF BISHOP BERKELEY THE " TREATISE OF HUMAN NATURE" AND OF SCEPTICISM. The present age,I apprehend, has not pro- duced two- more acute or more practised in this part of philosophy, than the Bishop of Cloyne, and the author of the " Treatise of Human Nature." The first was no friend to scepticism, but had that warm concern for religious and moral principles which be- came his order : yet the result of his inquiry was a serious conviction that there is no such thing as a material world — nothing in nature but spirits and ideas ; and that the belief of material substances, and of abstract ideas, are the chief causes of all our errors in philosophy, and of all infidelity and heresy in religion. His arguments are founded upon the principles which were formerly laid down by Des Cartes, Malebranche, and Locke, and which have been very generally received. And the opinion of the ablest judges seems to be, that they neither have been, nor can be confuted ; and that he hath proved by unanswerable arguments what no man in his senses can believe. 102 OF THE HUMAN MIND. The second proceeds upon the same prin- ciples, but carries them to their full length ; and, as the Bishop undid the whole material world, this author, upon the same grounds, undoes the world of spirits, and leaves no- thing in nature but ideas and impressions, without any subject on which they may be impressed. It seems to be a peculiar strain of humour in this author, to set out in his introduction by promising, with a grave face, no less than a complete system of the sciences, upon a foundation entirely new — to wit, that of hu- man nature — when the intention of the whole work is to shew, that there is neither human nature nor science in the world. It may perhaps be unreasonable to complain of this conduct in an author who neither believes his own existence nor that of his reader ; and therefore could not mean to disappoint him, or to laugh at his credulity. Yet I cannot imagine that the author of the " Treatise of Human Nature" is so scep- tical as to plead this apology. He believed, against his principles, that he should be read, and that he should retain his personal identity, till he reaped the honour and repu- tation justly due to his metaphysical acumen. Indeed, he ingeniously acknowledges, that it was only in solitude and retirement that he could yield any assent to his own philo- sophy ; society, like day-light, dispelled the darkuess and fogs of scepticism, and made him yield to the dominion of common sense. Nor did I ever hear him charged with doing anything, even in solitude, that argued such a degree of scepticism as his principles maintain. Surely if his friends apprehended this, they would have the charity never to leave him alone. Pyrrho the Elean, the father of this phi- losophy, seems to have carried it to greater perfection than any of his successors : for, if we may believe Antigonus the Carystian, quoted by Diogenes Laertius, his life cor- responded to his doctrine. And, therefore, if a cart run against him, or a dog attacked him, or if he came upon a precipice, he would not stir a foot to avoid the danger, giving no credit to his senses. But his at- tendants, who, happily for him, were not so great sceptics, took care to keep him out of harm's way ; so that he lived till he was ninety years of age. Nor is it to be doubted but this author's friends would have been equally careful to keep him from harm, if ever his principles had taken too strong a hold of him. It is probable the " Treatise of Human Nature'' was not written in company ; yet it contains manifest indications that the author every now and then relapsed into the faith of the vulgar, and could hardly, for half a dozen pages, keep up the scep- tical character. In like manner, the great Pyrrho him- self forgot his principles on some occasions ; and is said once to have been in such a passion with his cook, who probably had not roasted his dinner to his mind, that with the spit in his hand, and the meat upon it, he pursued him even into the market- place.* It is abold philosophy that rejects, without ceremony, principles which irresistibly go- vern the belief and the conduct of all man- kind in the common concerns of life ; and to which the philosopher himself must yield, after he imagines he hath confuted them. Such principles are older, and of more au- thority, than Philosophy : she rests upon them as her basis, not they upon her. If she could overturn them, she must be buried in their ruins ; but all the engines of philo- sophical subtilty are too weak for this pur- pose ; and the attempt is no less ridiculous than if a mechanic should 1 contrive an axis in peritrochio to remove the earth out of its place ; or if a mathematician should pre- tend to demonstrate that things equal to the same thing are not equal to one an- other. Zeno-f- endeavoured to demonstrate the impossibility of motion ;$ Hobbes, that there was no difference between right and wrong ; and this author, that no credit is to be given to our senses, to our memory, or even to demonstration. Such philosophy is< justly ridiculous, even to those who cannot detect the fallacy of it. It can have no other tend- ency, than to shew the ?cuteness of the sophist, at the expense of disgracing reason and human nature, and making mankind Yahoos. Section VI. OF THE " TREATISE OP HUMAN NATURE." There are other prejudices against this system of human nature, which, even upon a general view, may make one diffident of it. Des Cartes, Hobbes, and this author, have each of them given us a system of human nature ; an undertaking too vast for any one man, how great soever his genius and abilities may be. There must surely be reason to apprehend, that many pajjts of human nature never came under their observation; and that others have been stretched and distorted, to fill up blanks, and complete the system. Christopher » Laertius, L. ix. Seg 68. — H. f Zeno of Elea There are fifteen Zenos known in the history of Philosophy ; of these, Laertius sig. nalizes eight. — H. t The fallacy of Zeno's exposition of the contra, dictions involved in our notion ci motion, has nut yet been detected. — H. INTRODUCTION. 103 Columbus, or Sebastian Cabot, might almost as reasonably have undertaken to give us a complete map of America. There is a certain character and style in Nature's works, which is never attained in the most perfect imitation of them. This seems to be wanting in the systems of human nature I have mentioned, and par- ticularly in the last. One may see a pup- pet make variety of motions and gesticula- tions, which strike much at first view ; but when it is accurately observed, and taken to pieces, our admiration ceases : we com- prehend the whole art of the maker. How unlike is it to that which it represents ! What a poor piece of work compared with the body of a man, whose structure the more we know, the more wonders we dis- cover in it, and the more sensible we are of our ignorance ! Is the mechanism of the mind so easily comprehended, when that of the body is so difficult ? Yet, by this sys- tem, three laws of association, joined to a few original feelings, explain the whole mechanism of sense, imagination, memory, belief, and of all the actions and passions of the mind. Is this the man that Nature made ? I suspect it is not so easy to look behind the scenes in Nature's work. This is a puppet, surely, contrived by too bold an apprentice of Nature, to mimic her work. It shews tolerably by candle light ; but, brought into clear day, and taken to pieces, it will appear to be a man made with mor- tar and a trowel. The more we know of other parts of nature, the more we like and approve them. The little I know of the planetary system ; of the earth which we inhabit ; of minerals, vegetables, and ani- mals ; of my own body ; and of the laws which obtain in these parts of nature — opens to my mind grand and beautiful scenes, and contributes equally to my happiness and power. But, when I look within, and con- sider the mind itself, which makes me capable of all these prospects and enjoy- ments — if it is, indeed, what the " Treatise of Human Nature" makes it — I find I have been only in an enchanted castle, imposed upon by spectres and apparitions. I blush inwardly to think how I have been deluded ; I am ashamed of my frame, and can hardly forbear expostulating with my destiny. Is this thy pastime, O Nature, to put such tricks upon a silly creature, and then to take off the mask, and shew him how he hath been befooled ? If this is the philosophy of human nature, my soul enter thou not into ! her secrets ! It is surely the forbidden ' tree of knowledge ; I no sooner taste of it, j than I perceive myself naked, and stript of all things — yea, even of my very self. I see myself, and the whole frame of nature, shrink into fleeting ideas, which, like Epi- curus's atoms, dance about in emptiness. Section VI I. THE SYSTEM OF ALL THESE AUTHORS IS THE SAME, AND LEADS TO SCEPTICISM. But what if these profound disquisitions into the first principles of human nature, do naturally and necessarily plunge a man into this abyss of scepticism ? May we not reasonably judge so from what hath hap- pened ? Des Cartes no sooner began to dig in this mine, than scepticism was ready to break in upon him. He did what he could to shut it out. Malebranche and Locke, who dug deeper, found the difficulty of keeping out this enemy still to increase ; but they laboured honestly in the design. Then Berkeley, who carried on the work, despairing of securing all, bethought him- self of an expedient : — By giving up the material world, which he thought might be spared without loss, and even with ad- vantage, he hoped, by an impregnable par- tition, to secure the world of spirits. But, alas ! the " Treatise of Human Nature" wantonly sapped the foundation of this partition, and drowned all in one universal deluge. These facts, which are undeniable, do, indeed, give reason to apprehend that Des Cartes' system of the human understand- ing, which I shall beg leave to call the ideal system, and which, with some improvements made by later writers, is now generally received, hath some original defect ; that this scepticism is inlaid in it, and reared along with it ; and, therefore, that we must lay it open to the foundation, and examine the materials, before we can expect to raise any solid and useful fabric of knowledge on this subject. Section VIII. WE OUGHT NOT TO DESPAIR OF A BETTER. But is this to be despaired of, because Des Cartes and his followers have failed ? By no means. This pusillanimity would be injurious to ourselves and injurious to truth. Useful discoveries are sometimes indeed the effect of superior genius, but more fre- quently they are the birth of time and of accidents. A travellerof good judgment may mistake his way, and be unawares led into a wrong track ; and, while the road is fair before him, he may go on without suspicion and be followed by others; but, when it ends in a coal-pit, it requires no great judg- ment to know that he hath gone wrong, nor perhaps to find out what misled him. In the meantime, the unprosperous state of this part of philosophy hath produced an 104 OF THE HUMAN MIND. effect, somewhat discouraging indeed to any attempt of this nature, but an effect which might be expected, and which time only and better success can remedy. Sen- sible men, who never will be sceptics in matters of common life, are apt to treat with sovereign contempt everything that hath been said, or is to be said, upon this subject. It is metaphysic, say they : who minds it ? Let scholastic sophisters en- tangle themselves in their own cobwebs ; I am resolved to take my own existence, and the existence of other things, upon trust ; and to believe that snow is cold, and honey sweet, whatever they may say to the contrary. He must either be a fool, or want to make a fool of me, that would reason me out of my reason and senses. I confess I know not what a sceptic can answer to this, nor by what good argument he can plead even for a hearing ; for either his reasoning is sophistry, and so deserves contempt ; or there is no truth in human faculties — and then why should we reason ? If, therefore, a man findhimself intangled in these metaphysical toils, and can find no other way to escape, let him bravely cut the knot which he cannot loose, curse me- taphysic, and dissuade every man from meddling with it ; for, if I have been led into bogs and quagmires by following an ign'is fatuus, what can I do better than to warn others to beware of it ? If philoso- phy contradicts herself, befools her votaries, and deprives them of every object worthy to be pursued or enjoyed, let her be sent back to the infernal regions from which she must have had her original. But is it absolutely certain that this fair lady is of the party ? Is it not possible she may have been misrepresented ? Have not men of genius in former ages often made their own dreams to pass for her oracles ? Ought she then to be condemned without any further hearing ? This would be unreasonable. I have found her in all other matters an agreeable companion, a faithful counsellor, a friend . to common sense, and to the happiness of mankind. This justly entitles her to my correspond- ence and confidence, till I find infallible proofs of her infidelity. CHAPTER II. OF SMELLING. Section I. THE ORDER OP PROCEEDING — OF THE MEDIUM AND ORGAN OF SMELL. It is so difficult to unravel the operations of the human understanding, and to reduce them to their first principles, that we can. not expect to succeed in the attempt, but by beginning with the simplest, and pro- ceeding by very cautious steps to the more complex. The five external senses may, for this reason, claim to be first considered in an analysis of the human faculties. And the same reason ought to determine us to make a choice even among the senses, and to give the precedence, not to the noblest or most useful, but to the simplest, and that whose objects are least in danger of being mistaken for other things. In this view, an analysis of our sensa- tions may be carried on, perhaps with most ease and distinctness, by taking them in this order : Smelling, Tasting, Hearing, Touch, and, last of all, Seeing. Natural philosophy informs us, that all animal and vegetable bodies, and probably all or most other bodies, while exposed to the air, are continually sending forth efflu- via of vast subtilty, not only in their state of life and growth, but in the states of fer- mentation and putrefaction. These volatile particles do probably repel each other, and so scatter themselves in the air, until they meet with other bodies to which they have some chemical affinity, and with which they unite, and form new concretes. All the smell of plants, and of other bodies, is caused by these volatile parts, and is smelled wher- ever they are scattered in the air : and the acuteness of smell in some animals, shews us, that these effluvia spread far, and must be inconceivably subtile. Whether, as some chemists conceive, every species of bodies hath a spiritus rector, a kind of soul, which causes the smell and all the specific virtues of that body, and which, being extremely volatile, flies about in the air in quest of a proper receptacle, I do not inquire. This, hke most other theories, is perhaps rather the product of imagination than of just induction. But that all bodies are smelled by means of effluvia* which they emit, and which are drawn into the nostrils along with the air, there is no reason to doubt. So that there is manifest appearance of design in placing the organ of smell in the inside of that canal, through which the air is continually passing in inspiration and expiration. Anatomy informs us, that the membrane, pituilaria, and the olfactory nerves, which are distributed to the villous parts of this membrane, are the organs destined by the * It ia wrong to say that "a body is smelled by means of effluvia " Nothing is smelt but the effluvia themselves. They constitute the total object of per- ception in smell j and in all the senses the only object perceived, is that in immediate contact with the or. gan. There is, in reality, no medium in any sense; and, as Democritus long ago shrewdly observed, all the senses arc only modifications of touch H. OF SMELLING. I0!5 wisdom of nature to this sense; so that when a body emits no effluvia, or when they do not enter into the nose, or when the pituitary membrane or olfactory nerves are rendered unfit to perform their office, it can- not be smelled. Yet, notwithstanding this, it is evident that neither the organ of smell, nor the medium, nor any motions we can conceive excited in the membrane above mentioned, or in the nerve or animal spirits, do in the least resemble the sensation of smelling; nor could that sensation of itself ever have led us to think of nerves, animal spirits, or effluvia. Section II. THE SENSATION CONSIDERED ABSTRACTLY. Having premised these things with re- gard to the medium and organ of this sense, let us now attend carefully to what the mind is conscious of when we smell a rose or a lily; and, since our language affords no other name for this sensation, we shall call it a smell or odour, carefully excluding from the meaning of those names everything but the sensation itself, at least till we have ex- amined it. Suppose a person who never had this sense before, to receive it all at once, and to smell a rose — can he perceive any simi- litude or agreement between the smell and the rose ? or indeed between it and any other object whatsoever ? Certainly he can- not. He finds himself affected in a new way, he knows not why or from what cause. Like a man that feels some pain or pleasure formerly unknown to him, he is conscious that he is not the cause of it himself; but cannot, from the nature of the thing, deter- mine whether it is caused by body or spirit, by something near, or by something at a distance. It has no similitude to anything else, so as to admit of a comparison ; and, therefore, he can conclude nothing from it, unless, perhaps, that there must be some unknown cause of it. It is evidently ridiculous to ascribe to it figure, colour, extension, or any other quality of bodies. He cannot give it a place, any more than he can give a place to mel- ancholy or joy ; nor can he conceive it to have any existence, but when it is smelled. So that it appears to be a simple and original affection or feeling of the mind, altogether inexplicable and unaccountable. It is, in- deed, impossible that it can be in any body : it is a sensation, and a sensation can only be in a sentient thing. The various odours have each their dif- ferent degrees of strength or weakness. Most of them are agreeable or disagree- able; and frequently those that are agree- able when weak, are disagreeable when stronger. When we compare different smells together, we can perceive very few resemblances or contrarieties, or, indeed, relations of any kind between them. They are all so simple in themselves, and so dif- ferent from each other, that it is hardly possible to divide them into genera and species. Most of the names we give them are particular ; as the smell of a rose, of a jessamine, and the like. Yet there are some general names — as sweet, slinking, musty, putrid, cadaverous, aromatic. Some of them seem to refresh and animate the mind, others to deaden and depress it. Section III. SENSATION AND REMEMBRANCE, NATURAL PRINCIPLES OB BELIEF. So far we have considered this sensation abstractly. Let us next compare it with other things to which it bears some relation. And first I shall compare this sensation with the remembrance, and the imagination of it. I can think of the smell of a rose when I do not smell it ; and it is possible that when I think of it, there is neither rose nor smell anywhere existing. But when I smell it, I am necessarily determined to believe that the sensation really exists. This is common to all sensations, that, as they cannot exist but in being perceived, so they cannot be perceived but they must exist. I could as easily doubt of my own existence, as of the existence of my sensations. Even those profound philosophers who have endeayoured to disprove their own existence, have yet left their sensations to stand upon their own bottom, stript of a subject, rather than call in question the reality of their existence. Here, then, a sensation, a smell for in- stance, may be presented to the mind three different ways : it may be smelled, it may be remembered, it may be imagined or thought of. In the first casg, it is neces- sarily accompanied with a belief of its pre- sent existence ; in the second, it is neces- sarily accompanied with a belief of its past existence ; and in the last, it is not accom- panied with belief at all,* but is what the logicians call a simphapprehension. Why sensation sHould ^GoTfTpel our belief of the present existence of the thing, me- mory a belief of its past existence, and # This is not strictly correct. The imagination of an object is necessaiily accompanied with a belief of the existence of the mental representation. Heid uses the term existence for objective existenc only, and tnkes no account of tlie possibility of a subjecttvi. existence 10(5 OF THK HUMAN MIND. imagination no belief at all, I believe no philosopher can give a shadow of reason, but that such is the nature of these opera- tions : they are all simple and original, and therefore inexplicable acts of the mind. Suppose that once, and only once, I smelled a tuberose in a certain room, where it grew in a pot, and gave a very grateful perfume. Next day I relate what I saw and smelled- When I attend as carefully as I can to what passes in my mind in this case, it appears evident that the very thing I saw yesterday, and the fragrance I smelled, are now the immediate objects of my mind, when I remember it. Further, I can imagine this pot and flower transported to the room where I now sit, and yielding the same perfume. Here likewise it appears, that the individual thing which I saw and smelled, is the object of my imagination.* Philosophers indeed tell me, that the immediate object of my memory and ima- gination* in this case, is not the past sensa- tion, but an idea of it, an image, phantasm, or species, -f* of the odour I smelled : that this idea now exists in my mind, or in my sensorium ; and the mind, contemplating this present idea, finds it a representation of what is past, or of what may exist ; and accordingly calls it memory, or imagination. This is the doctrine of the ideal philosophy ; which we shall not now examine, that we may not interrupt the thread of the present investigation. Upon the strictest atten- tion, memory appears to me to have things that are past, and not present ideas, for its object. "We shall afterwards examine this system of ideas, and endeavour to make it appear, that no solid proof has ever been advanced of the existence of ideas ; that they are a mere fiction and hypothesis, con- trived to solve the phsenomena of the hu- man understanding ; that they do not at all answer this end ; and that this hypothesis of ideas or images of things in the mind, or in the sensorium, is the parent of those many paradoxes so shocking to common sense, and of that scepticism which disgrace our philosophy of the mind, and have brought upon^it the ridicule and contempt of sensible men. In the meantime, I beg leave to think, with the vulgar, that, when I remember the smell of the tuberose, that very sensation which I had yesterday, and which has now * For an exposition of Reid's error in regard to the- immediate objeci of Memory and Imagination, spe Note B at the end of the volume.— H. t It will be observed, that Keid understands by Id a, Image, Phantasm, Species, S[C always ater- tium quid rmrm-rically differentboth from the Object existing and from the Subject knowing. He had formed nn conception of a doctrine in which a representative object is allowed, but only as a modification of the mind itself. On the evil consequences of this error, both on his own philosophy and on his criticism ot oi her opinions, see Note V at the md of the volume, no more any existence, is the immediate object of my memory ; and when I imagine it present, the sensation itself, and not any idea of it,is the object of my imagination. But, though the object of my sensation, memory, and imagination, be in this case the same, yet these acts or operations of the mind are as different, and as easily distinguishable, as smell, taste, and sound. I am conscious of a difference in kind between sensation and memory, and between both and imag- ination. I find this also, that the sensation compels my belief of the present existence of the smell, and memory my belief of its past existence. There is a smell, is the immediate testimony of sense; there was a smell, is the immediate testimony of mem- ory. If you ask me, why I believe that the smell exists, I can give no other reason, nor shall ever be able to give any other, than that I smell it. If you ask, why I believe that it existed yesterday, I can give no other reason but that I remember it. Sensation and memory, therefore, are simple, original, and perfectly distinct opera- tions of the mind, and both of them are original principles of belief. Imagination is distinct from both, but is no principle of belief. Sensation implies the present exist- ence of its object, memory its past existence, but imagination views its object naked, and without any belief of its existence or non- existence, and is therefore what the schools call Simple Apprehension. m Section IV. JUDGMENT AND BELIEF IN SOME CASES PRE CEDE SIMPLE APPREHENSION. f But here, again, the ideal system comes in our way: it teaches us that the first J* operation of the mind about its ideas, is yT simple apprehension —that is, the bare conception of a thing without any belief about it : and that, after we have got simple apprehensions, by comparing them together, we perceive agreements or dis- agreements between them ; and that this perception of the agreement or disagreement of ideas, is all that we call belief, judgment, or knowledge. Now, this appears to me to be all fiction, without any foundation in nature ; for it is acknowledged by all, that sensation must go before memory and im- agination ; and hence it necessarily follows, that apprehension, acompanied with belie) and knowledge, must go before simple ap- prehension, at least in the matters we are now speaking of. So that here, instead ol • Simple Apprehension, in the language of the Schools, has no relerence to any exclusion of belief, ll was merely given to (he conception ot simple, in contrast to the cognition of complex, terms H. OF SMELLING. 10; saying that the belief or knowledge is got by putting together and comparing the simple apprehensions, we ought rather to say that the simple apprehension is performed by resolving and analysing a natural and original judgment. And it is with the operations of the mind, in this case, as with natural bodies, which are, indeed, compounded of simple principles or ele- ments. Nature does not exhibit these ele- ments separate, to be compounded by us ; she exhibits them mixed and compounded in concrete bodies, and it is only by art and chemical analysis that they can be separated. Section V. TWO THEORIES OF THE NATURE OF BELIE!' REFUTED CONCLUSIONS FROM WHAT HATH BEEN SAID. But what is this belief or knowledge which accompanies sensation and memory ? Every man knows what it is, but no man can define it. Does any man pretend to define sensation, or to define con- sciousness ? It is happy, indeed, that no man does. And if no philosopher had endeavoured to define and explain belief, some paradoxes in philosophy, more in- credible than ever were brought forth by the most abject superstition or the most frantic enthusiasm, had never seen the light. Of this kind surely is that modern discovery of the ideal philosophy, that sensation, me- mory, belief, and imagination, when they have the same object, are only different degrees of strength and vivacity in the idea.* Suppose the idea to be that of a future state after death : one man believes it firmly — this means no more than that he hath a strong and lively idea of it ; another neither believes nor disbelieves — that is, he has a weak and faint idea. Suppose, now, a third person believes firmly that there is no such thing, I am at a loss to know whether his idea be faint or lively : if it is faint, then there may be a firm belief where the idea is faint ; if the idea is lively, then the belief of a future state and the belief of no future state must be one and the same. The same arguments that are used to prove that belief implies only a stronger idea of the object than simple apprehension, might as well be used to prove that love implies only a stronger idea of the object than indiffer- ence. And then what shall we say of hatred, which must upon this hypothesis be a degree of love, or a degree of indifference ? If it should be said, that in love there is something more than an idea — to wit, an affection of the mind — may it not be said * He refers lo IluiTitf.— H with equal reason, that in belief there is something more than an idea — to wit, an assent or persuasion of the mind ? But perhaps it may be thought as ridicu- lous to argue against this strange opinion, as to maintain it. Indeed, if a man should maintain that a circle, a square, and a triangle differ only in magnitude, and not in figure, I belieVe he would find nobody disposed either to believe him or to argue against him ; and yet I do not think it less shocking to oommon sense, to maintain that sensation, memory, and imagination differ only in degree, and not in kind. I know it is said, that, in a delirium, or in dreaming, men are apt to mistake one for the other. But does it follow from this, that men who are neither dreaming nor in a delirium cannot distinguish them ? But how does a man know that he is net in a delirium ? I cannot tell : neither can I tell how a man knows that he exists. But, if any man seri- ously doubts whether he is in a delirium, I think it highly probable that he is, and that it is time to seek for a cure, which I am persuaded he will not find in the whole system of logic. I mentioned before Locke's notion of belief or knowledge ; he holds that it con- sists in a perception of the agreement or disagreement of ideas ; and this he values himself upon as a very important discovery. We shall have occasion afterwards to examine more particularly this grand prin- ciple of Locke's philosophy, and to shew that it is one of the main pillars of modern scepticism, although he had no intention to make that use of it. At present let us only consider how it agrees with the instances of belief now under consideration ; and whether it gives any light to them. I be- lieve that the sensation I have exists ; and that the sensation I remember does not now exist, but did exist yesterday. Here, according to Locke's system, I compare the idea of a sensation with the ideas of past and present existence : at one time I per- ceive that this idea agrees with that of pre- sent existence, but disagrees with that of past existence ; but, at another time, it agrees with the idea of past existence, and disagrees with that of present existence. Truly these ideas seem to be very capri- cious in their agreements and disagree- ments. Besides, I cannot, for my heart, conceive what is meant by either. I say a sensation exists, and I think I understand clearly what I mean. But you want to make the thing clearer, and for that end tell me, that there is an agreement between the idea of that sensation and the idea of existence. To speak freely, this conveys to me no light, but darkness ; I can con- ceive no otherwise of it, than as an odd and obscure circumlocution. I conclude, then, 108 OF THE HUMAN MIND. that the belief which accompanies sensation and memory, is a simple act of the mind, which cannot be denned. It is, in this respect, like seeing and hearing, which can •never be so denned as to be understood by those who have not these faculties ; and to such as have them, no definition can make these operations more clear than they aru already. In like manne*r, every man that has any belief — and he must be a curiosity that has none — knows perfectly wl at belief is, but can never define or explain it. I conclude, also, that sensation, memory, and imagination, even where they have the same object, are operations of a quite dif- ferent nature, and perfectly distinguishable by those who are sound and sober. A man that is in danger of confounding them, is indeed to be pitied ; but whatever relief le may find from another art, he can find none from logic or metaphysic. I conclude fur- ther, that it is no less a part of the human constitution, to believe the present existence of our sensations, and to believe the past existence of what we remember, than it is to believe that twice two make four. The evidence of sense, the evidence of memory, and the evidence of the necessary relations of things, are all distinct and original kinds of evidence, equally grounded on our consti- tution : none of them depends upon, or can be resolved into another. To reason against any of these kinds of evidence, is absurd ; nay, to reason for them is absurd. They are first principles ; and such fall not with- in the province of reason," but of common sense. Section VI. APOLOGY FOR METAPHYSICAL ABSURDITIES — SENSATION WITHOUT A SENTIENT, A CON- SEQUENCE OP THE THEORY OF IDEAS CONSEQUENCES OF THIS STRANGE OPINION. Having considered the relation which the sensation of smelling bears to the remem- brance and imagination of it, I proceed to consider what relation it bears to a mind, or sentient principle. It is certain, no man can conceive or believe smelling to exist of itself, without a mind, or something that has the power of smelling, of which it is called a sensation, an operation, or feeling. Yet, if any man should demand a proof, that sensation cannot be without a mind or sentient being, I confess that I can give none ; and that to pretend to prove it, seems to me almost as absurd as to deny it. This might have been said without any apology before the '• Treatise of Human Nature" appeared in the world. For till tee Nnto + at p. 100. b — H. that time, no man, as far as I know, ever thought either of calling in question that principle, or of giving a reason for his belief of it. Whether thinking beings were of an ethereal or igneous nature, whether material or immaterial, was variously dis- puted ; but that thinking is an operation of some kind of being or other, was always taken for granted, as a principle that could not possibly admit of doubt. However, since the author above men- tioned, who is undoubtedly one of the most acute metaphysicians that this or any age hath produced, hath treated it as a vulgar prejudice, and maintained that the mind is only a succession of ideas and impres- sions without any subject ; his opinion, however contrary to the common appre- hensions of mankind, deserves respect. I beg therefore, once for all, that no offence may be taken at charging this or other metaphysical notions with absurdity, or with being contrary to the common sense of mankind. No disparagement is meant to the understandings of the authors or maintainers of such opinions. Indeed, they commonly proceed, not from defect of under- standing, but from an excess of refinement ; the reasoning that leads to them often gives new light to the subject, and shews real genius and deep penetration in the author; and the premises do more than atone for the conclusion. If there are certain principles, as I think there are, which the constitution of our nature leads us to believe, and which we are under a necessity to take for granted in the common concerns of life, without being able to give a reason for them — these are what we call the principles of common sense ; and what is manifestly contrary to them, is what we call absurd. Indeed, if it is true, and to be received as a principle of philosophy, that sensation and thought may be without a thinking being, it must be acknowledged to be the most wonderful discovery that this or any other age hath produced. The received doctrine of ideas is the principle from which it is deduced, and of which indeed it seems to be a just and natural consequence. And it is probable, that it would not have been so late a discovery, but that it is so shock- ing and repugnant to the common appre- hensions of mankind, that it required an uncommon degree of philosophical intre- pidity to usher it into the world. It is a fundamental principle of the ideal system, that every object of thought must be an impression or an idea — that is, a faint copy of some preceding impression. This is a principle so commonly received, that the author above mentioned, although his whole system is built upon it, never offers the least proof of it. It is upon this principle, OF SMELLING. 101) as a fixed point, that he erects his meta- physical engines, to overturn heaven and earth, body and spirit. And, indeed, in my apprehension, it is altogether sufficient for the purpose. For, if impressions and ideas are the only objects of thought, then heaven and earth, and body and spirit, and everything you please, must signify only impressions and ideas, or they must be words without any meaning. It seems, therefore, that this notion, however strange, is closely connected with the received doc- trine of ideas, and we must either admit the conclusion, or call in question the premises. Ideas seem to have something in their nature unfriendly to other existences. They were first introduced into philosophy, in the humble character of images or repre- sentatives of things ; and in this character they seemed not only to be inoffensive, but to serve admirably well for explaining the operations of the human understanding. But, since men began to reason clearly and j^ distinctly about them, they have by degrees supplanted their constituents, and under- mined the existence of everything but themselves. First, they discarded all se- condary qualities of bodies ; and it was found out by their means, that fire is not hot, nor snow cold, nor honey sweet ; and, in a word, that heat and cold, sound, colour, taste, and smell, are nothing but ideas or impressions. Bishop Berkeley advanced them a step higher, and found out, by just reasoning from the same principles, that extension, solidity, space, figure, and body, are ideas, and that there is nothing in nature but ideas and spirits. But the triumph of ideas was completed by the " Treatise of Human Nature," which discards spirits also, and leaves ideas and impressions as the sole existences in the universe. What if, at last, having nothing else to contend with, they should fall foul of one another, and leave no existence in nature at all ? This would surely bring philosophy into danger ; for what should we have left to talk or to dispute about ? However, hitherto these philosophers acknowledge the existence of impressions and ideas ; they acknowledge certain laws of attraction, or rules of precedence, accord- ing to which, ideas and impressions range themselves in various forms, and succeed one another : but that they should belong to a mind, as its proper goods and chattels, this they have found to be a vulgar error. These ideas are as free and independent as the birds of the air, or as Epicurus's atoms when they pursued their journey in the vast inane. Shall we conceive them like the films of things in the Epicurean system ? Principio hoc dico, rerum simulacra vagari, Multa modis multis, in cunctas undique parteie Tenuia, quee facile inter te junguntur in aurls, Obvia cum veniunt.--JL.uCR. Or do they rather resemble Aristotle's in- telligible species, after they are shot forth from the object, and before they have yet struck upon the passive intellect ? But why should we seek to compare them with any- thing, since there is nothing in nature but themselves ? They make the whole furni- ture of the universe ; starting into existence, or out of it, without any cause ; combining into parcels, which the vulgar call minds ; and succeeding one another by fixed laws, without time, place, or author of those laws. Vet, after all, these self-existent and in- dependent ideas look pitifully naked and destitute, when left thus alone in the uni- verse, and seem, upon the whole, to be in a worse condition than they were before. Des Cartes, Malebranche, and Locke, as they made much use of ideas, treated them hand- somely, and provided them in decent accom- modation ; lodging them either in the pineal gland, or in the pure intellect, or even in the divine mind. They moreover clothed them with a commission, and made them representatives of things, which gave them some dignity and character. But the "Trea- tise of Human Nature," though no less indebted to them, seems to have made but a bad return, by bestowing upon them this independent existence ; since thereby they are turned out of house and home, and set adrift in the world, without friend or con- nection, without a rag to cover their naked- ness ; and who knows but the whole system of ideas may perish by the indiscreet zeal of their friends to exalt them ? However this may be, it is certainly a most amazing discovery that thought and ideas may be without any thinking being — a discovery big with consequences which cannot easily be traced by those deluded mortals who think and reason in the com- mon track. We were always apt to ima- gine, that thought supposed a thinker, and love a lover, and treason a traitor : but this, it seems, was all a mistake ; and it is found out, that there may be treason with- out a traitor, and love without a lover, laws without a legislator, and punishment with- out a sufferer, succession without time, and motion without anything moved, or space in which it may move : or if, in these cases, ideas are the lover, the sufferer, the traitor, it were to be wished that the author of this discovery had farther condescended to ac- quaint us whether ideas can converse to- gether, and be under obligations of duty or gratitude to each other ; whether they can make promises and enter into leagues and covenants, and fulfil or break them, and be punished for the breach. If one set of ideas makes a covenant, another breaks it, and a third is punished for it, there is rea- son to think that justice is no natural virtue in this system. no OF THE HUMAN MIND. It seemed very natural to think, that the " Treatise of Human Nature'' required an author, and a very ingenious one too ; but now we learn that it is only a set of ideas which came together and arranged them- selves by certain associations andattractions. After all, this curious system appears not to be fitted to the present state of human nature. How far it may suit some choice spirits, who are refined from the dregs of common sense, I cannot say. It is acknow- ledged, I think, that even these can enter into this system only in their most specula- tive hours, when they soar so high in pur- suit of those self-existent ideas as to lose sight of all other things. But when they condescend to mingle again with the human race, and to converse with a friend, a com- panion, or a fellow-citizen, the ideal system vanishes ; common sense, like an irresist- ible torrent, carries them along ; and, in spite of all their reasoning and philosophy, they believe their own existence, and the existence of other things. Indeed, it is happy they do so ; for, if they should carry their closet belief into the world, the rest of mankind would con- sider them as diseased, and send them to an infirmary. Therefore, as Plato required certain previous qualifications of those who entered his school, I think it would be pru- dent for the doctors of this ideal philosophy to do the same, and to refuse admittance to every man who is so weak as to imagine that he ought to have the same belief in solitude and in company, or that his prin- ciples ought to have any influence upon his practice ; for this philosophy is like a hob- by-horse, which a man in bad health may ride in his closet, without hurting his repu- tation ; but, if he should take him abroad with him to church, or to the exchange, or to the play-house, his heir would imme- diately call a jury, and seize his estate. Section VII. THE CONCEPTION AND BELIEF OF A SENTIENT BEING OR MIND IS SUGGESTED BY OUR CONSTITUTION — THE NOTION OF RELA- TIONS NOT ALWAYS GOT BY COMPARING THE RELATED IDEAS. Leaving this philosophy, therefore, to those who have occasion for it, and can use it discreetly as a chamber exercise, we may still inquire how the rest of mankind, and even the adepts themselves, except in some solitary moments, have got so strong and irresistible a belief, that thought must have a subject, and be the act of some thinking being ; how every man believes himself to be something distinct from his ideas and impressions — something which continues the same identical self when all his ideas and impressions are changed. It is impossible to trace the origin of this opinion in history ; for all languages have it interwoven in their original con- struction. All nations have always believed it. The constitution of all laws and governments, as well as the common trans- actions of life, suppose it. It is no less impossible for any man to recollect when he himself came by this notion ; for, as far back as we can remem- ber, we were already in possession of it, and as fully persuaded of our own existence, and the existence of other things, as that one and one make two. It seems, there- fore, that this opinion preceded ail reason- ing, and experience, and instruction ; and this is the more probable, because we could not get it by any of these means. It ap- pears, then, to be an undeniable fact, that, from thought or sensation, all mankind, constantly and invariably, from the first dawning of reflection, do infer a power or faculty of thinking, and a permanent being or mind to which that faculty belongs ; and that we as invariably ascribe all the various kinds of sensation and thought we are con- scious of, to one individual mind or self. But by what rules of logic we make these inferences, it is impossible to shew ; nay, it is impossible to shew how our sensations and thoughts can give us the very notion and conception either of a mind or of a faculty. The faculty of smelling is some- thing very different from the actual sensa- tion of smelling ; for the faculty may remain when we have no sensation. And the mind is no less different from the faculty ; for it continues the same indivi- dual being when that faculty is lost. Yet' this sensation suggests to us both a faculty and a mind ; and not only suggests the notion of them, but creates a belief of their existence ; although it is impossible to dis-i cover, by reason, any tie or connection between one and the other. What shall we say, then ? Either those inferences which we draw from our sensa- tions — namely, the existence of a mind, and of powers or faculties belonging to it — are prejudices of philosophy or education, mere fictions of the mind, which a wise man should throw off as he does the belief of fairies ; or they are judgments of nature — judgments not got by comparing ideas, and perceiving agreements and disagreements, but immediately inspired by our constitu- tion. If this last is the case, as I apprehend it is, it will be impossible to shake off those opinions, and we must yield to them at last, though we struggle hard to get rid of them. And if we could, by a determined obstinacy, shake off the principles of our OF SMELLING. Ul nature, this ia not to act the philosopher, but the fool or the madman. It is incum- bent upon those who think that these are not natural principles, to shew, in the first place, how we can otherwise get the notion of a mind and its faculties; and then to shew how we come to deceive ourselves into the opinion that sensation cannot be without a sentient being. It is the received doctrine of philosophers, that our notions of relations can only be got by comparing the related ideas : but, in the present case, there seems to be an instance to the contrary. It is not by having first the notions of mind and sensa- tion, and then comparing them together, that we perceive the one to have the rela- tion of a subject or substratum, and the other that of an act or operation : on the contrary, one of the related things — to wit, sensation — suggests to us both the correlate and the relation. I beg leave to make use of the word sug- gestion, because I know not one more pro- per, to express a power of the mind, which seems entirely to have escaped the notice of philosophers, and to which we owe many of our simple notions which are neither impressions nor i deas, as well as many original principles of belief. I shall endeavour to illustrate, by an example, what I understand by this word. We all know, that a certain kind of sound suggests immediately to the mind, a coach passing in the street ; and not only pro- duces the imagination, but the belief, that a coach is passing. Yet there is here no comparing of ideas, no perception of agree- ments or disagreements, to produce this belief : nor is there the least similitude be- tween the sound we hear and the coach we imagine and believe to be passing.* * *' The word suggest'* (says Mr Stewart, in refer- ence to the preceding passage) " is much used by Berkeley, in this appropriate and technical sense, not only in his 'Theory of Vision,' but in his * Prin- ciples of Human Knowledge,' and in his 'Minute Philosopher.' It expresses, indeed, the cardinal principle on which his ''theory of Vision' hinges, and is now so incorporated with some of our best metaphysical speculations, that one cannot easily conceive how the use of it was so long dispensed with. Locke uses the word excite for the same purpose; but it seems to imply an hypothesis con- cerning the mechanism of the mind, and by no means expresses the fact in question, with the same force and precision. " 1 1 is remarkable, that Dr Reid should have thought it incumbent on him to apologise for introducing into philosophy a word so familiar to every person conversant with Berkeley's works. * 1 beg leave to make use of the word suggestion, because,' &c, " So far Dr Reid's use of the word coincides ex- actly with that of Berkeley; Dut the former will be found to annex to it a meaning more extensive than the latter, by employing it to comprehend, not only those intima ions which are the result of experience and habit ; hut another class of intimations, (quite overlooked by Berkeley,) those which reult from the original frame of the human mind."— Dfsserta- It is true that this suggestion is liot natural and original ; it is tlie result of ex- perience and habit. But I think it appears, from what hath been said, that there are natural suggestions : particularly, that sens- ation suggests the notion of present exist- ence, and the belief that what we perceive or feel does now exist ; that memory sug- gests the notion of past existence, and the belief that what we remember did exist in time past ; and that our sensations and thoughts do also suggest the notion of a mind, and the belief of its existence, and of its relation to our thoughts. By a like natural principle it is, that a beginning of existence, or any change in nature, sug- gests to us the notion of a cause, and com- pels our belief of its existence. And, in like manner, as shall be shewn when we come to the sense of touch, certain sensa- tions of touch, by the constitution of our nature, suggest to us extension, solidity, and motion, which are nowise like to sensations, aUhongh they have been hither- to confounded with them.* Hon on the History of Metaphysical and Ethical Science. P. 167. Second edition Mr Stewart might have adduced, perhaps, a higher and, certainly, a more proxima'e authority, in fa- vour, not merely of the term in general, but of Reid's restricted employment of it, as an intimation of what he and others have designated the Common Sense of mankind. The following sentence of Ter. tullian contains a singular anticipation, both of the philosophy and of the philosophical phraseology ol our author. Speaking of the universal beliet of the soul's immortality : — " Natura pleraque sugger. untur, quasi de publico sensu quo an imam Deus di- tare dignatus est."— De Anima, c. 2. Some strictures on Reid's employment of the term suggestion may be seen in the " Versuche" of Tetens, I., p. 508, sqq.— H. • This last statement is not historically correct. But, waving this, there may be adduced, in illustra- tion of ihe two last paragraphs, the following remarkable passage from St Augustine:—" au. Recte fortasse existimas. Sed responde obsecro, utrum omne quod per visum cognoscimus, videa- mus. ev. Ita credo, au. t 'redis etiam omne quod videndo cognoscimus, per visum nos cognoscere ? ev. Et hoc credo, au. Cur ergo plerumque fumum solum videndo, ignem subter latere cognoscimus quern non videmus ? ev. Verum dicis. Et jam non puto nos videre quicquid per visum cognoscimus : possu. mus enim, ut docuisti, aliud videndo aliud cognoscere qudd visus non attigerit. au. Quid, illud quod per visum sentimus, possumusne non videre ? ev. Nullo modo. au. Aliud est ergo sentire, aliud cognoscere, i v. Omnino ahud, nam sentimus fumum quern vide- mus, et ex eo ignem quern non videmus, subesse cog- noscimus. At'- Bene intelligis. Sed viriea oertecum hoc accidit, corpus nostrum, id est oculos, nihil pati ex igne, sed ex fumo quern solum vident. Etenim videre sentire, et sentire pati esse, iam supra con- sensimus. ev. Teneo, & assentior. au. Cum ergo per passionem corporis non latet at quid an imam , non continuosensus vocatur unus de quinque memoratis, sed cum ipsa passio non latet: namque ille ignis non visus, nee auditus, nee olfactus, nee gustatus, nee tactus a nobis, non tamen latet animam fumo Vii-o Et cum hoc non latere non vocetur sen\us, quia ex igne corpus nihil est passum, vocatur tamen cognitio ver senium, quia ex passione corporis quamvis alia, id est ex alterius rei visione, conjectatum est atquc compertum. iv. Intelligo, et optime video istud congruere ac favere illi definitioni tus, quam ut meam mini defendendam dedisti: nam ita memini e-se abs te sensum definitum, cum animam non latet quod patitur corpus. Itaque illud quodfuvius videtur, 112 OF THE HUMAN MIND. Section VIII. THERE IS A QUALITY OR VIRTUE IN BODIES, WHICH WE CALL THEIR SMELL — HOW THIS IS CONNECTED IN THE IMAGINATION WITH THE SENSATION. We have considered smell as signifying a sensation, feeling, or impression upon the mind ; and in this sense, it can only be in a mind, or sentient being : but it is evident that mankind give the name of .smell much more frequently to something which they conceive to be external, and to be a quality of body : they understand something by it which does not at all infer a mind; and have not the least difficulty in conceiving the air perfumed with aromatic odours in the deserts of Arabia, or in some uninhab- ited island, where the human foot never trod. Every sensible day-labourer hath as clear a notion of this, and as full a convic- tion of the possibility of it, as he hath of his own existence ; and can no more doubt of the one than of the other. Suppose that such a man meets with a modern philosopher, and wants to be in- formed what smell in plants is. The phi- losopher tells him, that there is no smell in plants, nor in anything but in the mind ; that it is impossible there can be smell but in a mind; and that all this hath been demonstrated by modern philosohy. The Vlain man will, no doubt, be apt to think him merry : but, if he finds that he is serious, his next conclusion will be that he is mad; or that philosophy, like magic, puts men into a new world, and gives them different faculties from common men. And thus philosophy and common sense are set at variance. But who is to blame for it ? In my opinion the philosopher is to blame. For if he means by smell, what the rest of mankind most commonly mean, he is cer- tainly mad. But if he puts a different meaning upon the word, without observing it himself, or giving warning to others, he abuses language and disgraces philo- sophy, without doing any service to truth : as if a man should exchange the meaning of the words daughter and cow, and then endeavour to prove to his plain neighbour, that his cow is his daughter, and his daughter his cow. I believe there is not much more wisdom in many of those paradoxes of the ideal philosophy, which to plain sensible men appear to be palpable absurdities, but with the adepts pass for profound discoveries. I eensum vocamus ; passi sunt enim eum oculi videndo qui sunt corporis partes et corpora ; ignem autem ex quo nihil corpus est possum , quamvis cognitus fuerit, scnsumnon vocamus. — Da Quantitate animae, c. xxiv. S 4i.— H. resolve, for my own part, always to pay a great regard to the dictates of common sense, and not to depart from them without absolute necessity : and, therefore, I am apt to think that there is really something in the rose or lily, which is by the vulgar called smell, and which continues to exist when it is not smelled : and shall proceed to inquire what this is ; how we come by the notion of it ; and what relation this quality or virtue of smell hath to the sens- ation which we have been obliged to call by the same name, for want of another. Let us therefore suppose, as before, a person beginning to exercise the sense of smelling ; a little experience will discover to him, that the nose is the organ of this sense, and that the air, or something in the air, is a medium of it. And finding, by farther experience, that, when a rose is near, he has a certain sensation, when it is removed, the sensation is gone, he finds a connection in nature betwixt the rose and and this sensation. The rose is considered as a cause, occasion, or antecedent of the sensation ; the sensation as an effect or consequence of the presence of the rose; they are associated in the mind, and con- stantly found conjoined in the imagination. But here it deserves our notice, that, although the sensation may seem more closely related to the mind its subject, or to the nose its organ, yet neither of these connections operate so powerfully upon the imagination as its connection with the rose its concomitant. The reason of this seems to be. that its connection with the mind is more general, and noway distinguisheth it from other smells, or even from tastes, sounds, and other kinds of sensations. The relation it hath to the organ is likewise general, and doth not distinguish it from other smells ; but the connection it hath with the rose is special and constant ; by which means they become almost insepar- able in the imagination, in like manner as thunder and lightning, freezing and cold. Section IX. THAT THERE IS A PRINCIPLE IN HUMAN NATURE, PROM WHICH THE NOTION OF THIS, AS WELL AS ALL OTHER NATURAL VIRTUES OR CAUSES, IS DERIVED. In order to illustrate further how we come to conceive a quality or virtue in the rose which we call smell, and what this smell is, it is proper to observe, that the mind begins very early to thirst after prin- ciples which may direct it in the exertion of its powers. The smell of a rose is a certain affection or feeling of the mind; and, as it is not constant, but comes and OF SMELLING. 113 goes, we want to know when and where we may expect it ; and are uneasy till we find something which, being present, brings this feeling along with it, and, being removed, removes it. This, when found, we call the cause of it ; not in a strict and philosophical sense, as if the feeling were really effected or produced by that cause, but in a popular sense ; for the mind is satisfied if there is a constant conjunction between them ; and such causes are in reality nothing else but laws of nature. Having found the smell thus constantly conjoined with the rose, the mind is at rest, without inquiring whether this conjunction is owing to a real efficiency or not ; that being a philosophical inquiry, which does not concern human life. But every discovery of such a constant conjunc- tion is of real importance in life, and makes a strong impression upon the mind. So ardently do we desire to find everything that happens within our observation thus connected with something else as its cause or occasion, that we are apt to fancy connec- tions upon the slightest grounds ; and this weakness is most remarkable in the ignor- ant, who know least of the real connections established in nature. A man meets with an unlucky accident on a certain day of the year, and, knowing no other cause of his misfortune, he is apt to conceive something unlucky in that day of the calendar ; and, if he finds the same connection hold a second time, is strongly confirmed in his supersti- tion. I remember, many years ago, a white ox was brought into this country, of so enormous a size that people came many miles to see him. There happened, some months after, an uncommon fatality among women in child-bearing. Two such uncom- mon events, following one another, gave a suspicion of their connection, and occasioned a common opinion among the country- people that the white ox was the cause of this fatality. However silly and ridiculous this opinion was, it sprung from the same root in human nature on which all natural philosophy grows — namely, an eager desire to find out connections in things, and a natural, ori- ginal, and unaccountable propensity to be- lieve that the connections which we have observed in time past will continue in time to come. Omens, portents, good and bad luck, palmistry, astrology, all the numer- ous arts of divination and of interpreting dreams, false hypotheses and systems, and true principles in the philosophy of nature, are all built upon the same foundation in the human constitution, and are distin- guished only according as we conclude rashly from too few instances, or cautiously fi om a sufficient induction. As it is experience only that discovers these connections between natural causes and their effects ; without inquiring further, we attribute to the cause some vague and indistinct notion of power or virtue to pro- duce the effect. And, in many cases, the purposes of life do not make it necessary to give distinct names to the cause and the effect. Whence it happens, that, being closely connected in the imagination, al- though very unlike to each other, one name serves for both ; and, in common discourse, is most frequently applied to that which, of the two, is most the object of our attention. This occasions an ambiguity in many words, which, having the same causes in all lan- guages, is common to all, and is apt to be overlooked even by philosophers. Some instances will serve both to illustrate and confirm what we have said. Magnetism signifies both the tendency of the iron towards the magnet, and the power of the magnet to produce that tendency ; and, if it was asked, whether it is a quality of the iron or of the magnet, one would per- haps be puzzled at first ; but a little atten- tion would discover, that we conceive a power or virtue in the magnet as the cause, and a motion in the iron as the effect ; and, although these are things quite unlike, they are so united in the imagination, that wc give the common name of magnetism to both. The same thing may be said of gru- vitalion, which sometimes signifies the tend- ency of bodies towards the earth, sometimes the attractive power of the earth, which we conceive as the cause of that tendency. We may observe the same ambiguity in some of Sir Isaac Newton's definitions ; and that even in words of his own making. In three of his definitions, he explains very distinctly what he understands by the abm hue quan- tity, what by the accelerative quantity, and what by the motive quantity, of a centri- petal force. In the first of these three definitions, centripetal force is put for the cause, which we conceive to be some power or virtue in the centre or central body ; in the two last, the same word is put for the effect of this cause, in producing velocity, or in producing motion towards that centre. Heat signifies a sensation, and et'lrf a contrary one ; but heat likewise signifies a quality or state of bodies, which hath no contrary, but different degrees. When a man feels the same water hot to one hand and cold to the other, this gives him occa- sion to distinguish between the feeling and the heat of the body ; and, although he knows that the sensations are contrary, he does not imagine that the body can have contrary qualities at the same time. And when he finds a different tnste in the same body in sickness and in health, he is easily convinced, that the quality in the body called taste is the same as before, although I 114 OF THE HUMAN MIND. the sensations he has from it are perhaps opposite. The vulgar are commonly charged by philosophers, with the absurdity of imagin- ing the smell in the rose to be something like to the sensation of smelling ; but I think unjustly ; for they neither give the same epithets to both, nor do they reason in the same manner from them. What is smell in the rose ? It is a quality or vir- tue of the rose, or of something proceeding from it, which we perceive by the sense of smelling ; and this is all we know of the matter. But what is smelling ? It is an act of the mind, but is never imagined to be a quality of the mind. Again, the sens- ation of smelling is conceived to infer neces- sarily a mind or sentient being ; but smell in the rose infers no such thing. We say, this body smells sweet, that stinks ; but we do not say, this mind smells sweet and that stinks. Therefore, smell in the rose, and the sensation which it causes, are not con- ceived, even by the vulgar, to be things of the same kind, although they have the same name. From what hath been said, we may learn that the smell of a rose signifies two things : First, a sensation, which can have no existence but when it is perceived, and can only be in a sentient being or mind ; Secondly, it signifies some power, quality, or virtue, in the rose, or in effluvia proceed- ing from it, which hath a permanent exist- ence, independent of the mind, and which, by the constitution of nature, produces the sensation in us. By the original con- stitution of our nature, we are both led to believe that there is a permanent cause of the sensation, and prompted to seek after it ; and experience determines us to place it in the rose. The names of all smells, tastes, sounds, as well as heat and cold, have a like ambiguity in all languages ; but it deserves our attention, that these names are but rarely, in common language, used to signify the sensations ; for the most part, they signify the external qualities which are indicated by the sensations — the cause of which phenomenon It take to be this. Our sensations have very different degrees of strength. Some of them are so quick and lively as to give us a great deal either of pleasure or of uneasiness. When this is the case, we are compelled to attend to the sensation itself, and to make it an object of thought and discourse ; we give it a name, which signifies nothing but the sensation ; and in this case we readily acknowledge, that the thing meant by that name is in the mind only, and not in any- thing external. Such are the various kinds of pain, sickness, and the sensations of hunger and other appetites. But, where the se.isation is not so interesting as to re- quire to be made an object of thought, our constitution leads us to consider it as a sign of something external, which hath u constant conjunction with it; and, having found what it indicates, we give a name to that : the sensation, having no proper name, falls in as an accessory to the thing signified by it, and is confounded under the same name. So that the name may, in- deed, be applied to the sensation, but most properly and commonly is applied to the thing indicated by that sensation. The sensations of smell, taste, sound, and colour, are of infinitely more importance as signs or indications, than they are upon their own account ; like the words of a language, wherein we do not attend to the sound but to the sense. Section X. WHETHEK IN SENSATION THE MIND IS ACTIVE OB PASSIVE ? There is one inquiry remains, Whether, in smelling, and in other sensations, the mind is active or passive ? This possibly may seem to be a question about words, or, at least, of very small importance ; how- ever, if it leads us to attend more accu- rately to the operations of our minds than we are accustomed to do, it is, upon that very account, not altogether unprofitable. I think the opinion of modern philosophers is, that in sensation the mind is altogether passive.* And this undoubtedly is so far true, that we cannot raise any sensation in our minds by willing it ; and, on the other hand, it seems hardly possible to avoid having the sensation when the object is presented. Yet it seems likewise to be true, that, in proportion as the attention is more or less turned to a sensation or diverted from it, that sensation is more or less perceived and remembered. Every one knows that very intense pain may be diverted by a surprise, or by anything that entirely occupies the mind. When we are engaged in earnest conversation, the clock may strike by us without being heard ; at least, we remember not, the next moment, that we did hear it. The noise and tumult of a great trading city is not heard by them who have lived in it all their days ; but it stuns those strangers who have lived in the peaceful retirement of the country. Whether, therefore, there can be any sensation where the mind is purely passive, I will not say ; but I think we are conscious of having given some attention to every sensation which we remember, though ever so recent. * This i 3 far too absolutely stated.— H. OF TASTING. 115 No doubt, where the impulse is strong and uncommon, it is as difficult to withhold attention as it is to forbear crying out in racking pain, or starting in a sudden fright. But how far both might be attained by strong resolution and practice, is not easy to determine. So that, although the Peri- patetics had no good reason to suppose an active and a passive intellect, since atten- tion may be well enough accounted an act of the will, yet I think they came nearer to the truth, in holding the mind to be in sensation partly passive and partly active, than the moderns, in affirming it toi be purely passive. Sensation, imagination, memory, and judgment, have, by the vulgar in alL ages, been considered as acts of the mind. The manner in which they are ex- pressed in all languages, shews this. When the mind is much employed in them, we say it is very active ; whereas, if they were impressions only, as the ideal philosophy would lead us to conceive, we ought, in such a case, rather to say, that the mind is very passive ; for, I suppose, no man would attribute great activity to the paper I write upon, because it receives variety of cha- racters. The relation which the sensation of smell bears to the memory and imagination of it, and to a mind or subject, is common to all our sensations, and, indeed, to all the oper- ations of the mind : the relation it bears to the will is common to it with all the powers of*understandiug ; and the relation itbears to that quality or virtue of bodies which it in- dicates, is common to it with the sensa- tions of taste, hearing, colour, heat, and cold — so that what hath been said of this sense, may easily be applied to several of our senses, and to other operations of the mind ; and this, I hope, will apologize for our insisting so long upon it. CHAPTER III. OF TASTING. A great part of what hath been said of the sense of smelling, is so easily applied to those of tasting and hearing, that we shall leave the application entirely to the reader's judgment, and save ourselves the trouble of a tedious repetition. It is probable that everything that affects the taste is, in some degree, soluble in the saliva. It is not conceivable how anything should enter readily, and of its own accord, as it were, into the pores of the tongue, palate, and fauces, unless it had some chemical affinity to that liquor with which these pores are always replete. It is, there- fore, an admirable contrivance of nature, that the organs of taste should always be moist with a liquor which is so universal a menstruum, anil which deserves to be ex- amined more than it hath been hitherto, both in that capacity, and as a medical unguent. Nature teaches dogs, and other animals, to use it in this last way ; and its subserviency both to taste and digestion shews its efficacy in the former. It is with manifest design and propriety, that the organ of this sense guards the entrance of the alimentary canal, as that of smell the entrance of the canal for respira- tion. And from these organs being placed in such manner that everything that enters into the stomach must undergo the scrutiny of both senses, it isplainthatthey were intended by nature to distinguish wholesome food from that which is noxious. The brutes have no other means of choosing their food ; nor would mankind, in the savage state. And it is very probable that the smell and taste, noway vitiated by luxury or bad habits, would rarely, if ever, lead us to a wrong choice of food among the produc- tions of nature ; although the artificial compositions of a refined and luxurious cookery, or of chemistry and pharmacy, may often impose upon both, and produce things agreeable to the taste and smell, which are noxious to health. And it is probable that both smell and taste are vitiated, and rendered less fit to perform their natural offices, by the unnatural kind of life men commonly lead in society. These senses are likewise of great use to distinguish bodies that cannot be distin- guished by our other senses, and to discern the changes which the same body under- goes, which, in many cases, are sooner per- ceived by taste and smell than by any other means. How many things are there in the market, the eating-house, and the tavern, as well as in the apothecary and chemist's shops, which are known to be what they are given out to be, and are perceived to be good or bad in their kind, only by taste or smell ? And how far our judgment of things, by means of our senses, might bo improved by accurate attention to the small differences of taste and smell, and other sensible qualities, is not easy to determine. Sir Isaac Newton, by a noble effort of his great genius, attempted, from the colour of opaque bodies, to discover the magnitude of the minute pellucid parts of which they are compounded: and who knows what new lights natural philosophy may yet re- ceive from other secondary qualities duly examined ? Some tastes and smells stimulate the nerves and raise the spirits : but such an artificial elevation of the spirits is, by the laws of nature, followed by a depression, which can only be relieved by time, or by the repeated use of the like stimulus. By ; 2 116 OF THE HUMAN MIND. the use of such things we create an appe- tite for them, which very much resembles, and hath all the force of a natural one. It is in this manner that men acquire an ap- petite for snuff, tobacco, strong liquors, laudanum, and the like. Nature, indeed, seems studiously to have set bounds to the pleasures and pains we have by these two senses, and to have con- fined them within very narrow limits, that we might not place any part of our happi- ness in them; there being hardly any smell or taste so disagreeable that use will not make it tolerable, and at last perhaps agreeable, nor any so agreeable as not to lose its relish by constant use. Neither is there any pleasure or pain of these senses which is not introduced or followed by some degree of its contrary, which nearly balances it; so that we may here apply the beautiful allegory of the divine So- crates — that, although pleasure and pain are contrary in their nature, and their faces look different ways, yet Jupiter hath tied them so together that he that lays hold of the one draws the other along with it. As there is a great variety of smells, seemingly simple and uncompounded, not only altogether unlike, but some of them contrary to others, and as the same thing may be said of tastes, it would seem that one taste is not less different from another than it is from a smell : and therefore it may be a question, how all smells come to be considered as one genus, and all tastes as another ? What is the generical distinction ? Is it only that the nose is the organ of the one and the palate of the other ? or, abstracting from the organ, is there not in the sensations themselves something common to smells, and some- thing else common to tastes, whereby the one is distinguished from the other ? It seems most probable that the latter is the case ; and that, under the appearance of the greatest simplicity, there is still in these sensations something of composition. If one considers the matter abstractly, it would seem that a number of sensations, or, indeed, of any other individual things, which are perfectly simple and uncom- pounded, are incapable of being reduced into genera and species ; because individuals which belong to a species must have some- thing peculiar to each, by which they are distinguished, and something common to the whole species. And the same may be said of species which belong to one genus. And, whether this does not imply some kind of composition, we shall leave to metaphy- sicians to determine. The sensations both of smell and taste do undoubtedly admit of an immense variety of modifications, which no language can express If man was to examine five hundred different wines, he would hardly find two of them that had precisely the same taste. The same thing holds in cheese, and in many other things. Yet, of five hundred different tastes in cheese or wine, we can hardly describe twenty, so as to give a distinct notion of them to one who had not tasted them. Dr Nehemiah Grew, a most judicious and laborious naturalist, in a discourse read before the Royal Society, anno 1675, bath endeavoured to shew that there are at least sixteen different simple tastes, which he enumerates.* How many compounded ones may be made out of all the various combinations of two, three, four, or more of these simple ones, they who are ac- quainted with the theory of combinations will easily perceive. AH these have va- rious degrees of intenseness and weakness. Many of them have other varieties ; in some the taste is more quickly perceived upon the application of the sapid body, in others more slowly — in some the sensation is more permanent, in others more transient — in some it seems to undulate or return after certain intervals, in others it is constant ; the various parts of the organ — as the lips, the tip of the tongue, the root of the tongue, the fauces, the uvula, and the throat— are some of them chiefly affected by one sapid body, and others by another. All these, and other varieties of tastes, that accurate writer illustrates by a number of examples. Nor is it to be doubted, but smells, if exa- mined with the same accuracy, would appear to have as great variety. CHAPTER IV. OP HEARING. Section I. VARIETY OF SOUNDS — THEIR PLACE AND DISTANCE LEARNED BY CUSTOM, WITHOUT REASONING. Sounds have probably no less variety of modifications, than either tastes or odours. For, first, sounds differ in tone. The ear is capable of perceiving four or five hun- dred variations of tone in sound, and pro- bably as many different degrees of strength ; by combining these, we have above twenty thousand simple sounds that differ either in tone or strength, supposing every tone to be perfect. But it is to be observed, that to make a perfect tone, a great many • Plato and Galen reckon seven, Aristotle and Theophrasrns efgtii species of simple tastes Amone the moderns, (as 1 recollect.) these are estimateo at ten, by Boerhaavc and Linnaeus ; by Haller, at I twelve H. OF HEARING. 117 undulations of elastic air are required, which must all be of equal duration and extent, and follow one another with perfect regularity ; and each undulation must be made up of the advance and recoil of in- numerable particles of elastic air, whose motions are all uniform in direction, force, and time. Hence we may easily conceive a prodigious variety in the same tone, aris- ing from irregularities of it, occasioned by the constitution, figure, situation, or man- ner of striking the sonorous body ; from the constitution of the elastic medium, or its being disturbed by other motions ; and from the constitution of the ear itself, upon which the impression is made. A flute, a violin, a hautboy, and a French horn, may all sound the same tone, and be easily distinguishable. Nay, if twenty human voices sound the same note, and with equal strength, there will still be some difference. The same voice, while it re- tains its p oper distinctions, may yet be varied many ways, by sickness or health, youth or age, leanness or fatness, good or bad humour. The same words spoken by foreigners and natives — nay, by persons of different provinces of the same nation — may be distinguished. Such an immense variety of sensations of smell, taste, and sound, surely was not given us in vain. They are signs by which we know and distinguish things without us ; and it was fit that the variety of the .'igns should, in some degree, correspond with the variety of the things signified by them. It seems to be by custom that we learn to distinguish both the place of things, and their nature, by means of their sound. That such a noise is in the street, such another in the room above me ; that this is a knock at my door, that a person walk- ing up stairs — is probably learnt by expe- rience. I remember, that once lying a- bed, and having been put into a fright, I heard my own heart beat; but I took it to be one knocking at the door, and arose and opened the door oftener than once, before I discovered that the sound was in my own breast. It is probable, that, pre- vious to all experience, we should as little know whether a sound came from the right or left, from above or below, from a great or a small distance, as we should know whether it was the sound of a drum, or a bell, or a cart. Nature is frugal in her operations, and will not be at the ex- pense of a particular instinct, to give us that knowledge which experience will soon produce, by means of a general principle of human nature. For a little experience, by the constitu- tion of human nature, ties together, not onl} in our imagination, but in our belief, those things which were in their nature un- connected. When I hear a certain sound, I conclude immediately, without reasoning, that a coach passes by. There are no pre- mises from which this conclusion is inferred by any rules of logic. It is the effect of a principle of our nature, common to us with the brutes. Although it is by hearing that we are capable of the perceptions of harmony and melody, and of all the charms of music, yet it would seem that these require a higher faculty, which we call a musical ear. This seems to be in very different degrees, in those who have the bare faculty of hear- ing equally perfect ; and, therefore, ought not to be classed with the external senses, but in a higher order. Section II. OP NATURAL LANGUAGE. One of the noblest purposes of sound un- doubtedly is language, without which man- kind would hardly be able to attain any degree of improvement above the brutes. Language is commonly considered as purely an invention of men, who by nature are no less mute than the brutes ; but, having a superior degree of invention and reason, have been able to contrive artificial signs of their thoughts and purposes, and to es- tablish them by common consent. But 1 he origin of language deserves to be more care- fully inquired into, not only as this inquiry may be of importance for the improvement of language, but as it is related to the pre- sent subject, and tends to lay open some of the first principles of human nature. I shall, therefore, offer some thoughts upon this subject. By language I understand all those signs which mankind use in order to communi- cate to others their thoughts and intentions, their purposes and desires. And such signs may be conceived to be of two kinds : First, such as have no meaning but what is affixed to them by compact or agreement among those who use them — these are ar- tificial signs; Secondly, such as, previous to all compact or agreement, have a mean- ing which every man understands by the principles of his nature. Language, so far as it consists of artificial signs, may be called artificial ; so far as it consists of natural signs, I call it natural. Having premised these definitions, I think it is demonstrable, that, if mankind had not a natural language, they could never have invented an artificial one by their reason and ingenuity. For all arti- ficial language supposes some compact or agreement to affix a certain meaning to 118 OF THE HUMAN MIND. certain signs ; therefore, there must be compacts or agreements before the use of artificial signs ; but there can be no com- pact or agreement without signs, nor with- out language ; and, therefore, there must be a natural language before any artificial language can be invented : which was to be demonstrated. Had language in general been a human invention, as much as writing or printing, we should find whole nations as mute as the brutes. Indeed, even the brutes have some natural signs by which they express their own thoughts, affections, and. desires, and understand those of others. A chick, as soon as hatched, understands the differ- ent sounds whereby its dam calls it to food, or gives the alarm of danger. A dog or a horse understands, by nature, when the human voice caresses, and when it threatens him. But brutes, as far as we know, have no notion of contracts or covenants, or of moral obligation to perform them. If na- ture had given them these notions, she would, probably have given them natural signs to express them. And where nature has denied these notions, it is as impossible to acquire them by art, as it is for a blind man to acquire the notion of colours. Some brutes are sensible of honour or disgrace ; they have resentment and gratitude ; but none of them, as far as we know, can make a promise or plight their faith, having no such notions from their constitution. And if mankind had not these notions by nature, and natural signs to express them by, with all their wit and ingenuity they could never have invented language. The elements of this natural language of mankind, or the signs that are naturally expressive of our thoughts, may, I think, be reduced to these three kinds : modula- tions of the voice, gestures, and features. By means of these, two savages who have no common artificial language, can converse together ; can communicate their thoughts in some tolerable manner; can ask and refuse, affirm and deny, threaten and sup- plicate ; can traffic, enter into covenants, and plight their faith. This might be con- firmed by historical facts of undoubted credit, if it were necessary. Mankind having thus a common language by nature, though a scanty one, adapted only to the necessities of nature, there is no great ingenuity required in improving it by the addition of artificial signs, to supply the deficiency of the natural. These artificial signs must multiply with the arts of life, and the improvements of knowledge. The articulations of the voice seem to be, of all signs, the most proper for artificial language ; and as mankind have universally used tliem for that purpose, we may reason- ably judge that nature intended them for it. But nature probably does not intend that we should lay aside the use of the natural signs; it is enough that we supply their defects by artificial ones. A man that rides always in a chariot, by degrees loses the use of his legs ; and one who uses artificial signs only, loses both the knowledge and use of the natural. Dumb people retain much more of the natural language than others, because necessity obliges them to use it. And for the same reason, savages have much more of it than civilized nations. It is by natural signs chiefly that we give force and energy to language ; and the less language has of theni, it is the less ex- pressive and persuasive. Thus, writing is less expressive than reading, and reading less expressive than speaking without book ; speaking without the proper and natural modulations, force, and variations of the voice, is a frigid and dead language, com- pared with that which is attended with them ; it is still more expressive when we add the language of the eyes and features ; and is then only in its perfect and natural state, and attended with its proper energy, when to all these we superadd the force of action. Where speech is natural, it will be an exercise, not of the voice and lungs only, but of all the muscles of the body ; like that of dumb people and savages, whose language, as it has more of nature, is more expressive, and is more easily learned. Is it not pity that the refinements of a civilized life, instead of supplying the de- fects of natural language, should root it out and plant in its stead dull and lifeless articulations of unmeaning sounds, or the scrawling of insignificant characters ? The perfection of language is commonly thought to be, to express human thoughts and sen- timents distinctly by these dull signs ; but if this is the perfection of artificial language, it is surely the corruption of the natural. Artificial signs signify, but they do not express ; they speak to the understanding, as algebraical characters may do, but the passions, the affections, and the will, hear them not : these continue dormant and inactive, till we speak to them in the lan- guage of nature, to which they are all atten- tion and obedience. It were easy to shew, that the fine arts of the musician, the painter, the actor, and the orator, so far as they are expressive — although the knowledge of them requires in us a delicate taste, a nice judgment, and much study and practice — yet they are nothing else but the language of nature, which we brought into the world with us, but have unlearned by disuse, and so find the greatest difficulty in recovering it. Abolish the use of articulate sounds and writing among mankind for a century. OF TOUCH. 119 nurl every man would 1)0 n painter, an actor, and an orator. We mean not to affirm that such an expedient is practica- ble; or, if it were, that the advantage would counterbalance the loss; hut that, as men are led by nature and necessity to converse together, they will use every mean in their power to make themselves under- stood ; and where they cannot do this by artificial signs, they will do it, as far as possible, by natural ones : and he that understands perfectly the use of natural signs, must be the best judge in all the ex- pressive arts. CHAPTER V. OF TOUCH. Section I. OP HEAT AND COLD. Th e senses which we have hitherto con- sidered, are very simple and uniform, each of them exhibiting only one kind of sensa- tion, and thereby indicating only one quality of bodies. By the ear we perceive sounds, and nothing else; by the palate, tastes; and by the nose, odours. These qualities are all likewise of one order, being all secondary qualities ; whereas, by touch we perceive not one quality only, but many, and those of very different kinds.* The chief of them are heat and cold, hardness and softness, roughness and smoothness, figure, solidity, motion, and extension. We shall consider these in order. As to heat and cold, it will easily be allowed that they are secondary qualities, of the same order with smell, taste, and sound. And, therefore, what hath been already said of smell, is easily applicable to them ; that is, that the words heat and cold have each of them two significations ; they sometimes signify certain sensations of the mind, which can have no existence when when they are not felt, nor can exist any- where but in a mind or sentient being ; but more frequently they signify a quality in bodies, which, by the laws of nature, occa- sions the sensations of heat and cold in us — a quality which, though connected by cus- tom so closely with the sensation, that we cannot, without difficulty, separate them, yet hath not the least resemblance to it, * It has been very commonly held by philosophers, hoth in ancient and modern times, that the division of the senses into five, is altogether inadequate ; and psychologists, though not at one in regard to the dis- tribution, are now generally agreed, that under Touch —or Feeling, in thestrictest signification of the term — are comprised perceptions which are, at least, as well entitled to be opposed in species, as those of Taste and Smell — II. and may continue to exist when there is no sensation at all. The sensations of heat and cold are per- fectly known ; for they neither are, nor can be, anything else than what we feel them to be ; but the qualities in bodies which we call heat and cold, are unknown. They are only conceived by us, as unknown causes or occasions of the sensations to which we give the same names. But, though common sense says nothing of the nature of these qualities, it plainly dictates the existence of them ; and to deny that there can be heat and cold when they are not felt, is an ab- surdity too gross to merit confutation. For what could be more absurd, than to say, that the thermometer cannot rise or fall, unless some person be present, or that the coast of Guinea would be as cold as Nova Zeinbla, if it had no inhabitants ? It is the business of philosophers to in- vestigate, by proper experiments and in- duction, what heat and cold are in bodies. And whether they make heat a particular element diffused through nature, and ac- cumulated in the heated body, or whether they make it a certain vibration of the parts of the heated body ; whether they de- termine that heat and cold are contrary qualities, as the sensations undoubtedly are contrary, or that heat only is a quality, and cold its privation : these questions are within the province of philosophy ; for com- mon sense says nothing on the one side or the other. But, whatever be the nature of that quality in bodies which we call heat, we certainly know this, that it cannot in the least resemble the sensation of heat. It is no less absurd to suppose a likeness be- tween the sensation and the quality, than it would be to suppose that the pain of the gout resembles a square or a triangle. The simplest man that hath common sense, does not imagine the sensation of heat, or anything that resembles that sensation, to be in the fire. He only imagines that there is something in the fire which makes him and other sentient beings feel heat. Yet, as the name of heat, in common lan- guage, more frequently and more properly signifies this unknown something in the fire, than the sensation occasioned by it, he justly laughs at the philosopher who denies that there is any heat in the fire, and thinks that he speaks contrary to com- mon sense. Section jl OP HARDNESS AND SOFTNESS. Let us next consider hardness and soft- ness ; by which words we always under- 120 OF THE HUMAN MIND. stand real properties or qualities of bodies of which we have a distinct conception. When the parts of a body adhere so firmly that it cannot easily be made to change its figure, we call it hard ; when its parts are easily displaced, we call it soft. This is the notion which all mankind have of hardness and softness ; they are neither sensations, nor like any sensation ; they were real qualities before they were perceived by touch, and continue to be so when they are not perceived ; for if any man will affirm that diamonds were not hard till they were handled, who would reason with him ? There is, no doubt, a sensation by which we perceive a body to be hard or soft. This sensation of hardness may easily be had, by pressing one's hand against the table, and attending to the feeling that ensues, setting aside, as much as possible, all thought of the table and its qualities, or of any external thing. But it is one thing to have the sens- ation, and another to attend to it, and make it a distinct object of reflection. The first is very easy ; the last, in most cases, ex- tremely difficult. We are so accustomed to use the sensa- tion as a sign, and to pass immediately to the hardness signified, that, as far as appears, it was never made an object of thought, either by the vulgar or by philosophers ; nor has it a name in any language. There is no sensation more distinct, or more frequent ; yet it is never attended to, but passes through the mind instantaneously, and serves only to introduce that quality in bodies, which, by a law of our constitution, it suggests. There are, indeed, some cases, wherein it is no difficult matter to attend to the sens- ation occasioned by the hardness of a body; for instance, when it is so violent as to occa- sion considerable pain : then nature calls upon us to attend to it, and then we acknow- ledge that it is a mere sensation, and can only be in a sentient being. If a man runs his head with violence against a pillar, I appeal to him whether the pain he feels re- sembles the hardness of the stone, or if he can conceive anything like what he feels to be in an inanimate piece of matter. The attention of the mind is here entirely turned towards the painful feeling ; and, to speak in the common language of mankind, he feels nothing in the stone, but feels a violent pain in his head. It is quite other- wise when he leans his head gently against the pillar ; for then he will tell you that he feels nothing in his head, but feels hardness in the stone. Hath he not a sensation in this case as well as in the other ? Un- doubtedly he hath ; but it is a sensation which nature intended only as a sign of something in the stone ; and, accordingly, he instantly fixes his attention upon the hing signified ; and cannot, without grat difficulty, attend so much to the sensation as to be persuaded that there is any such thing distinct from the hardness it signifies. , But, however difficult it may be to attend to this fugitive sensation, to stop its rapid progress, and to disjoin it from the external quality of hardness, in whose shadow it is apt immediately to hide itself ; this is what a philosopher by pains and practice must attain, otherwise it will be impossible for him to reason justly upon this subject, or even to understand what is here advanced. For the hist appeal, in subjects of this na- ture, must be to what a man feels and per- ceives in his own mind. » It is indeed strange that a sensation which we have every time we feel a body hard, and which, consequently, we can com- mand as often and continue as long as we please, a sensation as distinct and determi- nate as any other, should yet be so much unknown as never to have been made an object of thought and reflection, nor to have been honoured with a name in any language ; that philosophers, as well as the vulgar, should have entirely overlooked it, or confounded it with that quality of bo- dies which we call hanine^ r to which it hath not the least similitude. May we not hence conclude, that the knowledge of the human faculties is but in its infancy ? — that we have not yet learned to attend to those operations of the mind, of which we are conscious every hour of our lives ? — that there are habits of inattention ac- quired very early, which are as hard to be overcome as other habits ? For I think it is probable, that the novelty of this sensa- tion will procure some attention to it in children at first ; but, being in nowise inte- resting in itself, as soon as it becomes familiar, it is overlooked, and the attention turned solely to that which it signifies. Thus, when one is learning a language, ho attends to the sounds ; but when he is mas- ter of it, he attends only to the sense of what he would express. If this is the case, we must become as little children again, if we will be philosophers ; we must over- come this habit of inattention which has been gathering strength ever since we began to think — a habit, the usefulness of which, in common life, atones for the dif- ficulty it creates to the philosopher in dis- covering the first principles of the human mind. The firm cohesion of the parts of a body, • is no more like that sensation by which I perceive it to be hard, than the vibration of a sonorous body is like the sound I hear : nor can I possibly perceive, by my reason, any connection between the one and the other. No man can give a reason, why the vibration of a body might not have given the sensation of smelling, and the effluvia OK TOUCH. 121 of bodies affected our hearing, if it had so pleased our Maker. In like manner, no man can give a reason why the sensations of smell, or taste, or sound, might not have indicated hardness, as well as that sensa- tion which, by our constitution, does indi- v cute it. Indeed, no man can conceive any sensation to resemble any known quality of bodies. Nor can any man shew, by any Hood argument, that all our sensations might not have been as they are, though no body, nor quality of body, had ever existed. • Here, then, is a phseiiomenon of human nature, which comes to be resolved. Hard- ness of bodies is a thing that we conceive as distinctly, and believe as firmly, as any- thing in nature. We have no way of com- ing at this conception and belief, but by means of a certain sensation of touch, to which hardness hath not the least simili- tude ; nor can we, by any rules of rea- soning, infer the one from the other. The question is, How we come by this conception ' and belief ? First, as to the conception : Shall we call it an idea of sensation, or of reflection ? The last will not be affirmed ; and as little can the first, unless we will call that an idea of sensation which hath no resem- blance to any sensation. So that the origin of this idea of hardness, one of the most common and most distinct we have, is not to be found in all our systems of the mind : not even in those which have so copiously endeavoured to deduce all our notions from sensation and reflection. But, secondly, supposing we have got the conception of hardness, how come we by the belief of it ? Is it self-evident, from comparing the ideas, that such a sensation could not be felt, unless such a quality of bodies existed ? No. Can it be proved by probable or certain arguments ? No ; it cannot. Have we got this belief, then, by tradition, by education, or by experience ? No ; it is not got in any of these ways. Shall we then throw off this belief as hav- ing no foundation in reason ? Alas ! it is not in our power ; it triumphs over reason, and laughs at all the arguments ofa philoso- pher. Even the author of the " Treatise of Human Nature,*' though he saw no rea- son for this belief, but many against it, could hardly conquer it in his speculative and solitary moments ; at other times, he fairly yielded to it, and confesses that he found himself under a necessity to do so. "' What shall we say, then, of this concep- tion, and this belief, which are so unac- countable and untractable ? I see nothing left, but to conclude, that, by an original principle of eur constitution, a certain sens- ation of touch both suggests to the mind the conception of hardness, and creates the belief of it : or, in other words, that this sens- ation is a natural tign of hardness. And this I shall endeavour more fully to explain. Section III. Of NATURAL SIGNS. As in artificial signs there is often neither similitude between the sign and thiog signified, nor any c nnection that arises necessarily from the nature of the things, so it is also in natural signs The word told has no similitude to the substance signified by it ; nor is it in its own nature more tit to signify this than any other sub- stance ; yet, by habit and custom, it sug- gests this and no other. In like manner, a sensation of touch suggests hardness, although it hath neither similitude to hard- ness, nor, as far as we can perceive, any necessary connection with it. The differ- ence betwixt these two signs lies oidy in this — that, in the first, the suggestion is the effect of habit and custom ; in the second, it is not the effect of habit, but of the ori- ginal constitution of our minds. It appears evident from what hath been said on the subject of language, that there are natural signs as well as artificial ; and particularly, that the thoughts, purposes, and dispositions of the mind, have their natural signs in the features of the face, the modulation of the voice, and the motion and attitude of the body : that, without a natural knowledge of the connection between these signs and the things signified by them, language could never have been invented and established among men : and, that the fine arts are all founded upon this connec- tion, which we may call the natural lani/nmin of mankind. It is now proper to observe, that there are different orders of natural signs, and to point out the different classes into which they may be distinguished, that we may more distinctly conceive the rela- tion between our sensations and the things they suggest, and what we mean by calling sensations signs of external things. The first class of natural signs compre- hends those whose connection with the thing signified is established by nature, but discovered only by experience. The whole i of genuine philosophy consists in discover- ing such connections, and reducing them to general rules. The great Lord Verulam had a perfect comprehension of this, when he called it an intt revelation of jiatur \ No man ever more distinctly understood or happily expressed the nature and founda- tion of the philosophic art. What is all we know of mechanics, astronomy, and optics, but connections established by nature, and discovered by experience or observation, and consequences deduced from them ? J 22 OF THE HUMAN MIND. All the knowledge we have in agriculture, gardening, chemistry, and medicine, is built upon the same foundation. And if ever our philosophy concerning the human mind is carried so far aa to deserve the name of science, which ought never to be despaired of, it must be by observing facts, reducing them to general rules, and drawing just con- clusions from them. What we commonly call natural causes might, with more pro- priety, be called natural «?'"?>«, and what we pall effects, the things signified. The causes have no proper efficiency oifJasualityJasfar as we know ; and all we can certaintyaflfirm is, that nature hath established a constant conjunction between them and the things called their effects ; and hath given to man- kind a disposition to observe those con- nections, to confide in their continuance, and to make use of them for the improvement of our knowledge, and increase of our power. A second class is that wherein the con- nection between the sign and thing signi- fied, is not only established by nature, but discovered to us by a natural principle, without reasoning or experience. Of this kind are the natural signs of human thoughts, purposes, and desires, which have been already mentioned as the natural language of mankind. An infant may be put into a fright by an angry countenance, and soothed again by smiles and blandish- ments. A child that has a good musical ear, may be put to sleep or to dance, may be made merry or sorrowful, by the modula- tion of musical sounds. The principles of all the fine arts, and of what we call a fine taste, may be resolved into connections of this kind. A fine taste may be improved by reasoning and experience ; but if the first principles of it were not planted in our minds by nature, it could never be ac- quired. Nay, we have already made it appear, that a great part of this knowledge which we have by nature, is lost by the disuse of natural signs, and the substitution of artificial in their place. A third class of natural signs compre- hends those which, though we never before had any notion or conception of the thing signified, do suggest it, or conjure it up, as it were, by a natural kind of magic, and at ence give us a conception and create a belief of it. I shewed formerly, that our sensations suggest to us a sentient being or mind to which they belong — a being which hath a permanent existence, although the sensations are transient and of short dura- tion — a being which is still the same, while its sensations and other operations are varied ten thousand ways — a being which hath the same relation to all that infinite variety of thoughts, purposes, actions, affections, enjoyments, and sufferings, which we are conscious of, or can remember. The conception of a mind is neither an idea of sensation nor of reflection : for it is neither like any of our sensations, nor like any- thing we are conscious of. The first con- ception of it, as well as the belief of it, and of the common relation it bears to all that we are conscious of, or remember, is suggested to every thinking being, we do not know how. The notion of hardness in bodies, as well » as the belief of it, are got in a similar manner ; being, by an original principle of our nature, annexed to that sensation which we have when we feel a hard body. « And so naturally and necessarily does the sensation convey the notion and belief of hardness, that hitherto they have been confounded by the most acute inquirers into the principles of human nature, al- though they appear, upon accurate reflec- tion, not only to be different things, but as unlike as pain is to the point «f a sword. 1 It may be observed, that, as the first class of natural signs I have mentioned is the foundation of true philosophy, and the second the foundation of the fine arts, or of taste— so the last is the foundation of common sense — a part of human nature which hath never been explained.* I take it for granted, that the notion of f hardness, and the belief of it, is first got by means of that particular sensation which, as far back as we can remember, does invariably suggest it ; and that, if we had never had such a feeling, we should never have had any notion of hardness. I think it is evident, that we cannot, by reasoning from our sensations, collect the existence of bodies at all, far less any of their qualities. This hath been proved by unanswerable arguments by the Bishop of Cloyne, and by the author of the " Treatise of Human Nature." It appears as evi- dent that this connection between our sens- ations and the conception and belief of external existences cannot bo produced by habit, experience, education, or any prin- ciple of human nature that hath been admitted by philosophers. At the same time, it is a fact that such sensations are invariably connected with the conception and belief of external existences. Hence, by all rules of just reasoning, we must con- clude, that this connection is the effect of our constitution, and ought to be considered as an original principle of human nature, till we find some more general principle into which it may be resolved. + * See Stewart's ** Elements of the Philosophy of the Human Mind." Vol II. , chap, i., $ 3, la>t note.— H. f This whole doctrine of natural s^ns, on which his philosophy is in a great measure established, was bor- rowed by Reid, in principle, and even in expression, from Bprkclev. Compare " Minute Philosopher, ' Dial. IV., M 7, II, IS; " New Theory or Vision " ijij 111, 117: "Theory of Vision Vindicated," SS 35 — 13—11. OF TOUCH. 123 Section IY. OF HARDNESS, AND OTHER PRIMARY QUALITIES. Further, I observe that hardness is a quality, of which we have as clear and distinct a conception as of anything what- soever. The cohesion of the parts of a body with more or less force, is perfectly understood, though its cause is not ; we know what it is, as well as how it affects the touch. It is, therefore, a quality of a quite different order from those secondary qualities we have already taken notice of, whereof we know no more naturally than that they are adapted to raise certain sens- ations in us. If hardness were a quality of the same kind, it would be a proper in- quiry for philosophers, what hardness in bodies is ? and we should have had various hypotheses about it, as well as about co- lour and heat. But it is evident that any such hypothesis would be ridiculous. If any man should say, that hardness in bo- dies is a certain vibration of their parts, or that it is certain effluvia emitted by them which affect our touch in the manner we feel — such hypotheses would shock com- mon sense ; because we all know that, if the parts of a body adhere strongly, it is hard, although it should neither emit efflu- via nor vibrate. Yet, at the same time, no man can say, but that effluvia, or the vibration of the parts of a body, might have affected our touch, in the same man- ner that hardness now does, if it had so pleased the Author of our nature ; and, if either of these hypotheses is applied to ex- plain a secondary quality — such as smell, or taste, or sound, or colour, or heat — there appears no manifest absurdity in the sup- position. The distinction betwixt primary and se- condary qualities hath had several revolu- tions. Democritus and Epicurus, and their followers, maintained it. Aristotle and the Peripatetics abolished it. Des Cartes, Malebranche, and Locke, revived it, and were thought to have put it in a very clear light. But Bishop Berkeley again dis- carded this distinction, by such proofs as must be convincing to those that hold the received doctrine of ideas.* Yet, after all, there appears to be a real found- ation for it in the principles of our na- ture. What hath been said of hardness, is so easily applicable, not only to its opposite, softness, but likewise to roughness and • On this distinction of Primary and Secondary Qualities, see " Essays on the lutel'ectual Powers," E.say II., chap. 17, and Mote 1), at the end uf the volume. — It. smoothness, to figure and motion, that we may be excused from making the applica- tion, which would only be a repetition of what hath been said. All these, by means of certain corresponding sensations of touch, are presented to the mind as real external qualities ; the conception and the belief of them are invariably connected with the corresponding sensations, by an original principle of human nature. Their sensa- tions have no name in any language ; they have not only been overlooked by the vul- gar, but by philosophers ; or, if they have been at all taken notice of, they have been confounded with the external qualities which they suggest. i Section V. OP EXTENSION. It is further to be observed, that hard- ness and softness, roughness and smooth- ness, figure and motion, do all suppose ex- tension, and cannot be conceived without it ; yet, I think it must, on the other hand, be allowed that, if we had never felt any thing hard or soft, rough or smooth, figured or moved, we should never have had a con- ception of extension ;* so that, as there is good ground to believe that the notion of extension could not be prior to that of other primary qualities, so it is certain that it could not be posterior to the notion of any of them, being necessarily implied in them alLf Extension, therefore, seems to be a qua- \ lity svgijested to us, by the very same sens- ations which suggest the other qualities above mentioned. When I grasp a ball in my hand, I perceive it at once hard, figured, and extended. The feeling is very simple, and hath not the least resemblance to any quality of body. Yet it suggests to us three primary qualities perfectly dis- tinct from one another, as well as from the sensation which indicates them. When I move my hand along the table, the feel- ing is so simple that I find it difficult to distinguish it into things of different na- tures; yet, it immediatey suggests hardness, smoothness, extension, and motion — tilings * According to Reid,-Exte> sion (Spare) is a no- tion a posteriori, the result of experience. Accord- ing to Kant, it is a prion ; experience only affording the occasions required hy the mind to exert the acts, of which theintuiiinn ol spare is a condition. Toe." [This allusion has puzzled our Scotti-h psychologists, Hu tenesmi evi- dently refer* to the sixth sense, ur sense of venereal tit. illation, proposed by the elder Scaliger, and approved of by Bacon, Buffon, Vnltaire, <\e.j ** The following general account may possibly be useful. (I )— That certain motions raised in our bodies are, by a general law, constituted the < ccasv n of perceptions in the ti'intt. (2°) These perceptions never come' entirely alone, but have some other perception joined with them. Thus every sensation is accompanied with the idea of Duration, and pet duration it not a.sens- tb>e idea, since it also accompanies ideas of inter- mil consciousness or reflection : so the idea of Humber may accompany any sensible ideas, and yet may also accompany any other ideas, as well asextcr. nal sensations. Brutes, when several object-, arc before them, have probably all the proper ideas of sight which we have, without the idea of number. (3°) r-ome idea-> are found at co?nnanyh/g the most different sensations, which yet aro not to be perceived s parately from s-ome.sensible quality. Such are Ex- le.i.sion, Figure, Motion, and Best, which aeci inpmi) the ideas ot Sight or Colours, and yet m.-iy be per. ceived without them, asm the idea- ot I ouch, at lea t it we move our organs along the parts ot ti.e btxly touched. Extension, Figure, Motion, or Kest, s only represented x<\ us in a modification of the self-conscious Ego. This doctrine being admitted, the Idralist has only toshew that the supposition ot a Non-Ego, or external world really existent, is a groundless and unnecessary assumption; for, while the law of parcnnony 'pro- hibits the multiplication of substances or causes be- yond what the phsnomona require, v.e have mani- festly no right to postulate for the Non-Eg ■ the dig- nity of an iudependent substance beyond the Ego, seeing that this Non.Ego is, ex hypothetic known to us, consequently exists for us, only as a phenomenon of the tigo.— Now, the.doctrinc of our Scottish philo- sophers is, in (act, the very groundwork on which the Egoistical Idenlism reposes. That'doctrine not only maintains our nensations of the secondary qua- lities to be the mere effects of certain unknown causes, of which we are consequently entitled to affirm nothing, butthat wehavenodirectand imme- diate perception of extension and the otherprimary qualities of matter. To limit ourselves to extension, (or space,) which figure and motion (the two other qualities proposed by Reid fur the experiment) sup. pose, it ig evident that if extension be not immediately perceived as externally existing, extended objects cannot be immediately perceived as realities out, and independent, of the percipient subject ; for, it we were capable of such a perception ot such objects, we should uecessarilybe also capable of a perception of this, the one essential attribute of their existence. But, on the doctrine i f our Scottish philosophers, Extension is a notion.suggested on occasion of sens- ations supposed to bedctermined by certain unknown causes ; which unknown causes are again supposed to be existences independent of the mind, and ex- tended — (heir complement, in fact, constituting the external world All our knowledge of the Non-Ego is thus merely ideal and mediate; we have no knowledge of any really objective reality* except through a subjective representation or notion; in other words, we are only Immediately cognizant of certain modes of our own minds, and, in and through them, mediately warned of the phenomena of the material universe. In all essential respects, this doc- trine of Reid and Stewart is. identical with Kant's; except that the German philosopher, in holding space OF TOUCH. 129 Tf our philosophy concerning the mind be so lame with regard to the origin of our notions of the clearest, most simple, and most familiar objects of thought, and the powers from which they are derived, can we expect that it should be more perfect in the account it gives of the origin of our opinions and belief ? We have seen already some instances of its imperfection in this respect ; and, perhaps, that same nature which hath given us the power to conceive things altogether unlike to any of our sens- ations, or to any operation of our minds, hath likewise provided for our belief of them, by some part of our constitution hitherto not explained. Bishop Berkeley hath proved, beyond the possibility of reply, that we cannot by reasoning infer the existence of matter from our sensations ; and the author of the " Treatise of Human Nature'' hath proved no less clearly, that we cannot by reasoning infer the existence of our own or other minds from our sensations. But are we to admit nothing but what can be proved hy reasoning ? Then we must be sceptics in- deed, and believe nothing at all. The author of the " Treatise of Human Na- ture" appears to me to be but a half-sceptic. He hath not followed his principles so far as they lead him ; but, after having, with un- paralleled intrepidity and success, combated vulgar prejudices, when he had but one blow to strike, his courage fails him, he fairly lays down his arms, and yields him- self a captive to the most common of all vulgar prejudices — I mean the belief of the existence of his own impressions and ideas. * to be a necessary form of our conceptions of external things, prudently declined asserting that these un- known things are, in themselves, extended. Now, the doctrine of Kant has been rigorously proved hy Jacdhi and Fichte fo be, in its legitimate issue, a doctiineof absolute Ideali-m; and the de- monstralions which the philosopher of Koenigsberg has given of the existence of an external world, have been long admitted, even by his disciples themselves, to he inconclusive. But our Scottish philosophers appeal to an argument which the German philoso- pher overtly rejected-the argument, as it is called, from common sense. In their hands however, this argument is unavailing ; lor, if it be good against the conclusions of the Idealist, it is good against the pre- mises which thev afiord h m. '1 he common sense of mankind only assures us of the existence of an ex- ternal and extended world, in assuring usihatwe are conscious, ivj merely of the phenomena of mind in relation to miuter, but of the phenomena of mat- ter in relation to mind— in other words, that we are immediately percipient of extended things. Reid himself seems to have become obscurely aware of this condition ; and, though he never retracted his doctrine concerning the mere sut>L estion of exten i n, we find, in his " Essays on the Intellectual Powers," assertions in regard to the immediate perception of external things, which would tend to shew that his later views were more in unison with the ne- cessary convictions of mankind. But of this again. * There is in this and the two following para- graphs a confusion and inaccuracy which it is re- quisite to notice— There is no scepticism possible touching the facts of consciousness in themselves. We cannot doubt that the phenomena of conecious- I beg, therefore, to have the honour of making an addition to the sceptical system, without which I conceive it cannot hang together. I affirm, that the belief of the existence of impressions and ideas, is as lit- tle supported by reason, as that of the exist- ence of minds and bodies. No man ever did or could offer any reason for this belief. ness are real, in so far as we are conscious of them. I cannot doubt, for example, that I am actually conscious of a certain feeling of fragrance, and or certain perceptions of colour, figure, \c when I see and mella rose. Of the reality of these, a a expe- rienced, I cannot doubt, because rln*y are facts of consciousne.-s ; and of consciousness I cannot dnubt, because such doubt being itself an act of consci< u . ness, W'iuld contradict, and, consequently, annilu. late itself. Bin of all beyond the mere phenomena of which we are conscious, we may — without fiar of self-contradiction at least— doubt. I may, lor in- stance, doubt whether the rose I see and smell has any existence bejond a phamoinenal existence in my consciousness. I cannot doubt that I am con. scious of it as something d fterent from self, but whe- ther it have, indeed, any reality beyond my mind — whether the not-se/fbc not in truth only self— that I may philos- phically question. In like manner, I am conscious of Mh> memory of a certain pant event. Of the contents of this memory, as a phenomenon Kiven in consciousness, scepticism is impossible. But I may by possibility demur to the reality of all be- yond these contents and the sphere ol present con- sciousness. In Reid's strictures upon Hume, he confounds two opposite things: He reproaches that philosopher with inconsequence, in holding to " the belief of the existence-Of his own impressions and ideas." Now, if, by the existence of impressions and ideas, Reid meant their existence as mere phenomena of con- sciousness, his criticism is inept; for a disbelief of their existence, as such phenomena, would have been a suicidal act in the sceptic. If, again, he meant by imtressions and ideas the hypothesis of representative entities different from the mind and its modifications; in that case the oljection is equally invalid. Hume was a sceptic ; i hat is, he acccp ed the premises afforded him by the dogmatist, and carried these premises to their legitimate con- sequences. To blame Hume, therefore, for not having doubted of his borrowed principles, is to tilame the sceptic for not performing a part altogether incon- sistent with his vocation. But, in point of fact, the hypothe is of such entities is ot no value to the idealist or sceptic. Impressions and fleas, viewed as menial modes, would have answered Hume's pur- pose not a whit \vor*e than impressions and ideas viewed as objects, but not as affections of mind. The most consistent scheme of idealism known in the history of philosophy is that of Fichte ; and Fichte's idealism is founded on a basis which ex- cludes that crude hypothesis of ideas on which alone Reid imagined any doctrine of Idealism could pos- sibly be established. And is the acknowledged result of the Fichtean dogmatism less a nihilism than the scepticism of Hume? " The sum to al," says Fichte, "is this; — There is absolutely nothing permanent either without me or within me, but only an un- ceasing change. I know a' S'lutciy nothing of any existence, not even of my own. I myself know nothing, and am nothing. Images (Bilder) there are : they constitute all that apparently exists, and what they know of them>elves is after the manner of images ; images that pass and vanish without there being aught to witness their transition ; that consist in fact of the image- of images, wiihouf sig- nificance and without an aim. 1 myself am one of these images; nay, I am not even thus much, but only a confused image of images All reality is con, verted into a marvellous dream, without a life to, d p edm of, and without a mind to dream; into a dream made up only of a drtam of itself. Percep- tion is a dream ; thought— the source of all the ex- istence and all the reality which I imagine to myself of my existence, of my power, of my destinations is the dream of that dream. "— H. 130 OF THE HUMAN MlND. Des Cartes took it for granted, that he thought, and had sensations and ideas ; so have all his followers done. Even the hero of scepticism hath yielded this point, I crave leaye to say, weakly and imprudently. I say so, because I am persuaded that there is no principle of his philosophy that obliged him to make this concession. And what is there in impressions and ideas so formid- able, that this all-conquering philosophy, after triumphing over every other existence, should pay homage to them ? Besides, the concession is dangerous : for belief is of such a nature, that, if you leave any root, it will spread ; and you may more easily pull it up altogether, than say, Hitherto shalt thou go and no further: the existence of impressions and ideas I give up to thee ; but see thou pretend to nothing more. A thorough and consistent sceptic will never, therefore, yield this point ; and while he holds it, you can never oblige him to yield anything else. To such a sceptic I have nothing to say ; but of the semi-sceptics, I should beg to know, why they believe the existence of their impressions and ideas. The true reason I take to be, because they cannot help it ; and the same reason will lead them to believe many other things. All reasoning must be from first prin- ciples ; and for first principles no other reason can be given but this, that, by the constitution of our nature, we are under a necessity of assenting to them. Such principles are parts of our constitution, no less than the power of thinking : reason can neither make nor destroy them ; nor can it do anything without them : it is like a telescope, which may help a man to see farther, who hath eyes; but, without eyes, a telescope shews nothing at all. A ma- thematician cannot prove the truth of his axioms, nor can he prove anything, unless he takes them for granted. We cannot prove the existence of our minds, nor even of our thoughts and sensations. A histo- rian, or a witness, can prove nothing, unless it is taken for granted that the memory and senses may be trusted. A natural philosopher ean prove nothing, unless it is taken for granted that the course of nature is steady and uniform. How or when I got such first principles, upon which I build all my reasoning, I know not ; for I had them before I can remember : but I am sure they are parts of my constitution, and that I cannot throw them off. That our thoughts and sensa- tions must have a subject, which we call ourselfj is not therefore an opinion got by reasoning, but a natural principle. That our sensations of touch indicate something external, extended, figured, hard or soft, is not n deduction of reason, but a natural principle. The belief of it, and the very conception of it, are equally parts of our constitution. If we are deceived in it, we are deceived by Him that made us, and there is no remedy.* I do not mean to affirm, that the sensa- tions of touch do, from the very first, sug- gest the same notions of body and its qua- lities which they do when we are grown up. Perhaps Nature is frugal in this, as in her other operations. The passion of love, with all its concomitant sentiments and desires, is naturally suggested by the perception of beauty in the other sex ; yet the same perception does not suggest tho tender passion till a certain period of life. A blow given to an infant, raises grief and lamentation ; but when he grows up, it as naturally stirs resentment, and prompts him to resistance. Perhaps a child in the womb, or for some short period of its existence, is merely a sentient being ; the faculties by which it perceives an external world, by which it reflects on its own thoughts, and existence, and relation to other things, as well as its reasoning and moral faculties, unfold themselves by degrees ; so that it is inspired with the various principles of com- mon sense, as with the passions of love and resentment, when it has occasion for them. Section VIII. OF THE SYSTEMS OF PHILOSOPHERS CONCERN- ING THE SENSES, "j* All the systems of philosophers about our senses and their objects have split upon this rock, of not distinguishing properly * The philosophers who have most loudly appealed to the veracity of God. and the natural conviction of mankind, in refutation of certain obnoxious inclu- sions, have tno often silently contradicted that vera- city and those convictions, when opposed to certain favourite opinions. But it is evident that such autho- rity is either good for all, or good for nothing. Our natural consciousness assures us (and the fact of that assurance is admitted by philosophers ot ail opinions) that we have an immediate knowledge of the very things themselves of an external and extended world ; and, on the ground ot this knowledgealone, is the belief oi mankind founded, that such a world really exists. Reid ought, therefore, either to have given up his doctrine of the mere suggestion of extension, &c., as subjective notions, on the occasion of sensation, or not to appeal t a the Divine veracity, and the-common sense of mankind, in favour of conclusions of which that doctrine subverts the foundation. In this in- consistency, Reid has, however, besides Deb Cartes, many distinguished copartners.— H. t On this subject, see " Essays on the Intellectual Powers,*' E>:say II., chap. 7-15, and the notes there- on. It is perhaps proper to recall to the reader*s-at. teniinn, thai, by the Ideal Theory, Reid always understands the ruder form of the doctrine, which holds that ideas are entities, different both from the external object and from the percipient mind, and that he had no conception of the finer form of that doctrine, which holds that all that we are conscious of in perception,, (of course also in imagination,) is only a ratification of the mind itself — Set; Not* C— H. OF TOUCH. 131 sensations which can have no existence but when they are felt, from the things sug- gested by them. Aristotle — with as dis- tinguishing a head as ever applied to philoso- phical disquisitions— confounds these two ; and makes every sensation to be the form, without the matter, of the thing perceived by it. As the impression of a seal upon wax has the form of the seal but nothing of the matter of it, so he conceived our sensa- tions to be impressions upon the mind, which bear the image, likeness, or form of the external thing perceived, without the mat- ter of it. Colour, sound, and smell, as well as extension, figure, and hardness, are, according to him, various forms of matter : our sensations are the same forms im- printed on the mind, a d perceived in its own intellect. It is evident from this, that Aristotle made no distinction between prim- ary and secondary qualities of bodies, al- though that distinction was made by De- mocritus, Epicurus, and others of the an- cients. • Des Cartes, Malebranche, and Locke, revived the distinction between primary and secondary qualities; but they made the secondary qualities mere sensations, and the primary ones resemblances of our sens- ations. They maintained that colour, sound, and heat, are not anything in bodies, but sensations, of the mind ; at the same time, they acknowledged some particular texture or modification of the body to be the cause or occasion of those sensations ; but to this modification they gave no name. Whereas, by the vulgar, the names of col- our, heat, and sound, are but rarely applied to the sensations, and most commonly to those unknown causes of them, as hath been already explained. The constitution of our nature leads us rather to attend to the things signified by the sensation than to the sensa- tion itself, and to give a name to the former rather than to the latter. Thus we see, that, with regard to secondary qualities, these philosophers thought with the vulgar, and with common sense. Their paradoxes were only an abuse of words; for when they maintain, as an important modern discovery, that there is no heat in the fire, they mean no more, than that the fire does not feel heat, which every one knew before. With regard to primary qualities, these philosophers erred more grossly. They indeed believed the existence of those qua- lities ; but they did not at all attend to the sensations that suggest them, which, having no names, have been as little con- sidered as if they had no existence. They were aware that figure, extension, and * On this last, see Aristotle. De Anima, L. III., c. 1, and Mctaph. L. III. c. 5 — The Aristotelic dis- tinction of first and second qualities was of another kind.— H. riee Norx i>, p. ozx u. hardness, are perceived by means of sens- ations of touch ; whence they rashly con- cluded, that these sensations must be images and resemblances of figure, extension, and hardness. The received hypothesis of ideas natur- ally led them to this conclusion : and indeed cannot consist with any other ; for, accord- ing to that hypothesis, external things must be perceived by means of images of them in the mind ; and what can those images of external things in the mind be, but the sensations by which we perceive them ? This, however, was to draw a conclusion from a hypothesis against fact. We need not have recourse to any hypothesis to know what our sensations are, or what they are like. By a proper degree of re- flection and attention we may understand them perfectly, and be as certain that they are not like any quality of body, as we can be, that the toothache is not like a triangle. How a sensation should instantly make us conceive and believe the existence of an external thing altogether unlike to it, I do not pretend to know ; and when I say that the one suggests the other, I mean not to explain the manner of their connection, but to express a fact, which every one may be conscious of— namely, that, by a law of our nature, such a conception and belief constantly and immediately follow the sens- ation. Bishop .Berkeley gave new light to this subject, by shewing, that the qualities of an inanimate thing, such as matter is con- ceived to be, cannot resemble any sensa- tion ; that it is impossible to conceive any- thing like the sensations of our minds, but the sensations of other minds. Every one that attends properly to his sensations must assent to this ; yet it had escaped all the philosophers that came before Berkeley; it had escaped even the ingenious Locke, who had so much practised reflection on the operations of his own mind. So diffi- cult it is to attend properly even to our own feelings. They are so accustomed to pass through the mind unobserved, and instantly to make way for that which na- ture intended them to signify, that it is extremely difficult to stop, and survey them ; and when we think we have ac- quired this power, perhaps the mind still fluctuates between the sensation and its associated quality, so that they mix to- gether, and present something to the ima- gination that is compounded of both. Thus, in a globe or cylinder, whose opposite sides are quite unlike in colour, if you turn it slowly, the colours are perfectly distinguish- able, and their dissimilitude is manifest ; but if it is turned fast, they lose their dis- tinction, and seem to be of one and the same colour. K3 132 OF THE HUMAN MIND. No succession can be more quick than that of tangible qualities to the sensations with which nature has associated them: but when one has once acquired the art of making them separate and distinct ob- jects of thought, he will then clearly per- ceive that the maxim of Bishop Berkeley, above-mentioned, is self-evident ; and that the features of the face are not more un- like to a passion of the mind which they indicate, than the sensations of touch are to the primary qualities of body. But let us observe what use the Bishop makes of this important discovery. Why, he concludes, that we can have no con- ception of an inanimate substance, such as matter is conceived to be, or of any of its qualities ; and that there is the strongest ground to believe that there is no existence in nature but minds, sensations, and ideas : if there is any other kind of existence , it must be what we neither have nor can have any conception of. But how does this follow ? Why, thus : We can have no conception of anything but what resem- bles some sensation or idea in our minds ; but the sensations and ideas in our minds can resemble nothing but the sensations and ideas in other minds ; therefore, the conclusion is evident. This argument, we see, leans upon two propositions. The last of them the ingenious author hath, indeed, made evident to all that understand his reasoning, and can attend to their own sensations : but the first proposition he never attempts to prove ; it is taken from the doctrine of ideas, which hath been so universally received by philosophers, that it was thought to need no proof- We may here again observe, that this acute writer argues from a hypothesis against fact, and against the common sense of man- kind. That we can have no conception of anything, unless there is some impression, sensation, or idea, in our minds which re- sembles it, is indeed an opinion which hath been very generally received among philo- sophers ; but it is neither self-evident, nor hath it been clearly proved ; and therefore it hath been more reasonable to call in question this doctrine of philosophers, than to discard the material world, and by that means expose philosophy to the ridicule of all men who will not offer up common sense as a sacrifice to metaphysics. We ought, however, to do this justice both to the Bishop of Cloyne and to the author of the " Treatise of Human Nature," to acknowledge, that their conclusions are justly drawn from the doctrine of ideas, which has been so universally received. On the other hand, from the character of Bishop Berkeley, and of his predecessors, Des Cartes, Locke, and Malebranche, we may venture to say, that, if they had seen all the consequences of this doctrine, as clearly as the author before mentioned did, they would have suspected it vehemently, and" examined it more carefully than they appear to have done. The theory of ideas, like the Trojan horse, had a specious appearance both of innocence and beauty ; but if those philo- sophers had known that it carried in its belly death and destruction to all science and common sense, they would not have broken down their walls to give it admit- tance. That we have clear and distinct con- ceptions of extension, figure, motion, and other attributes of body, which are neither sensations, nor like any sensation, is a fact of which we may be as certain as that we have sensations. And that all mankind have a fixed belief of an external material world — a belief which is neither got by rea- soning nor education, and a belief which we cannot shake off, even when we seem to have strong arguments against it and no shadow of argument for it — is likewise a fact, for which we have all the evidence that the nature of the thing admits. These facts are phsenomena of human nature, from which we may justly argue against any hypothesis, however generally received. But to argue from a hypothesis against facts, is contrary to the rules of true philo- sophy. CHAPTER VI. OF SEEING. Section I. THE EXCELLENCE AND DIGNITY Op THIS FACULTY. The advances made in the knowledge of optics in the last age and in the present, and chiefly the discoveries of Sir Isaac Newton, do honour, not to philosophy only, but to human nature. Such discoveries ought for ever to put to shame the ignoble attempts of our modern sceptics to depre- ciate the human understanding, and to dis- pirit men in the search of truth, by repre- senting the human faculties as fit for no- thing but to lead us into absurdities aud contradictions. Of the faculties called the five senses, sight is without doubt the noblest. The rays of light, which minister to this sense, and of which, without it, we could never have had the least conception, are the most wonderful and astonishing part of the inanimate creation. We must be satis- fied of this, if we consider their extreme minuteness ; their inconceivable velocity ; OF SEEING. 133 the regular variety of colours which they exhibit; the invariable laws according to which they are acted upon by other bodies, in their reflections, inflections, and r. fractions, without the least change of their original properties ; and the facility with which they pervade bodies of great density and of the closest texture, without resistance, without crowding or disturbing one another, without giving the least sensi- ble impulse to the lightest bodies. The structure of the eye, and of all its ap- purtenances, the admirable contrivances of nature for performing all its various exter- nal and internal motions, and the variety in the eyes of different animals, suited to their several natures and ways of life, clearly demonstrate this organ to be a mas- terpiece of Nature's work. And he must be very ignorant of what hath been dis- covered about it, or have a very strange cast of understanding, who can seriously doubt whether or not the rays of light and the eye were made for one another, with consummate wisdom, and perfect skill in optics. If we shall suppose an order of beings, endued with every human faculty but that of sight, how incredible would it appear to such beings, accustomed only to the slow informations of touch, that, by the addition of an organ, consisting of a ball and socket of an inch diameter, they might be enabled, in an instant of time, without changing their place, to percei\e the disposition of a whole army or the order of a battle, the figure of a magnificent palace or all the variety of a landscape ! If a man were by feeling to find out the figure of the peak of Teneriffe, or even of St Peter's Church at Rome, it would be the work of a lifetime.* It would appear still more incredible to such beings as we have supposed, if they were informed of the discoveries which may be made by this little organ in things far beyond the reach of any other sense : that by means of it we can find our way in the pathless ocean ; that we can traverse the globe of the earth, deter- mine its figure and dimensions, and deli- neate every region of it ; — yea, that we can measure the planetary orbs, and make discoveries in the sphere of the fixed stars. Would it not appear still more astonish- ing to such beings, if they should be farther informed, that, by means of this same organ, we can perceive the tempers and disposi- tions, the passions and affections, of our fellow-creatures, even when they want most to conceal them ?— that, when the tongue * The thing would be impossible. Let any one try by touch to ascertain the figure of a room, with which he is previously unacquainted, and not alto- gether of the usual shape, and he will find that 'ouch will afford him iiut slender aid — H. is taught most artfully to lie and dissemble, the hypocrisy should appear in the counte- nance to a discerning eye ? — and that, by this organ, we can often perceive what is straight and what is crooked in the mind as well as in the body ? How many myste- rious things must a blind man believe, if he will give credit to the relations of those that see ? Surely he needs as strong a faith as is required of a good Christian. It is not therefore without reason that the faculty of seeing is looked upon, not only as more noble than the other senses, but as having something in it of a nature superior to sensation. The evidence of reason is called seeing, not feeling, smelling, or lusting. Yea, we are wont to express the manner of the Divine knowledge by see- ing, as that kind of knowledge which is most perfect in us. Section II. SIGHT DISCOVERS ALMOST NOTHING WHICH THE BLIND MAY NOT COMPREHEND THE EEASON OF THIS. Notwithstanding what hath been said of the dignity and superior nature of this faculty, it is worthy of our observation, that there is very little of the knowledge ac- quired by sight, that may not be communi- cated to a man born blind. One who never saw the light, may be learned and knowing in every science, even in optics ; and may make discoveries in every branch of philo- sophy. He may understand as much as another man, not only of the order, dis- tances, and motions of the heavenly bodies ; but of the nature of light, and of the laws of the reflection and refraction of its rays. He may understand distinctly how thos-e laws produce the phenomena of the rain- bow, the prism, the camera obscura. and the magic lanthorn, and all the powers of the microscope and telescope. This is a fact sufficiently attested by experience. In order to perceive the reason of it, we must distinguish the appearance that objects make to the eye, from the things suggested by that appearance : and again, in the visi- ble appearance of objects, we must dis- tinguish the appearance of colour from the appearance of extension, figure, and motion. First, then, as to the visible appearance of the figure, and motion, and extension of bodies, I conceive that a man born blind may have a distinct notion, if not of the very things, at least of something extremely like to them. May not a blind man be made to conceive that a body mov- ing directly from the eye, or directly to- wards it, may ap] ear to be at rest ? and that the same motion may appear quicker 134 OF THE HUMAN MIND. or slower, according as it is nearer to the eye or farther off, more direct or more ob- lique ? May he not be made to conceive, that a plain surface, in a certain position, may appear as a straight line, and vary its visible figure, as its position, or the posi- tion of the eye, is varied ? — that a circle seen obliquely will appear an ellipse ; and a square, a rhombus, or an oblong rec- tangle ? Dr Saunderson understood the projection of the sphere, and the common rules of perspective ; and if he did, he must have understood all that I have men- tioned. If there were any doubt of Dr Saunderson's understanding these things, I could mention my having heard him say in conversation, that he found great difficulty in understanding Dr Halley's demonstra- tion of that proposition, that the angles made by the circles of the sphere, are equal to the angles made by their representatives in the stereographic projection ; but, said he, when I laid aside that demonstration, and considered the proposition in my own way, I saw clearly that it must be true. Another gentleman, of undoubted credit and judgment in these matters, who had part in this conversation, remembers it distinctly. As to the appearance of colour, a blind man must be more at a loss ; because he hath no perception that resembles it. Yet he may, by a kind of analogy, in part sup- ply this defect. To those who see, a scar- let colour signifies an unknown quality in bodies, that makes to the eye an ap- pearance which they are well acquainted with and have often observed — to a blind man, it signifies an unknown quality, that makes to the eye an appearance which he is unacquainted with. But he can conceive the eye to be variously affected by differ- ent colours, as the nose is by different smells, or the ear by different sounds. Thus he can conceive scarlet to differ from blue, as the sound of a trumpet does from that of a drum ; or as the smell of an orange differs from that of an apple. It is impossible to know whether a scarlet colour has the same appearance to me which it hath to another man ; and, if the appearances of it to different persons dif- fered as much as colour does from sound, they might never be able to discover this difference. Hence, it appears obvious, that a blind man might talk long about colours distinctly and pertinently ; and, if you were to examine him in the dark about the nature, composition, and beauty of them, he might be able to answer, so as not to betray his defect. We have seen how far a blind man may go in the knowledge of the appearances which things make to the eye. As to the things which are suggested by them or inferred from them, although he could never discover them of himself, yet he may understand them perfectly by the inform- ation of others. And everything of this kind that enters into our minds by the eye, may enter into his by the ear. Thus, for instance, he eould never, if left to the di- rection of his own faculties, have dreamed of any such thing as light ; but he can be informed of everything we know about it. He can conceive, as distinctly as we, the minuteness and velocity of its rays, their various degrees of refrangibility and reflexibility, and all the magical powers and virtues of that wonderful element. He could never of himself have found out, that there are such bodies as the sun, moon, and stars ; but he may be informed of all the noble discoveries of astrono- mers about their motions, and the lawf of nature by which they are regulated. Thus, it appears, that there is very little knowledge got by the eye, which may not be communicated by language to those who have no eyes. If we should suppose that it were as uncommon for men to see as it is to be born blind, would not the few who had this rare gift appear as prophets and in- spired teachers to the many ? We conceive inspiration to give a man no new faculty, but to communicate to him, in a new way, and by extraordinary means, what the fa- culties common to mankind can apprehend, and what he can communicate to others by ordinary means. On the supposition we have made, sight would appear to the blind very similar to this ; for the few who had this gift, could communicate the know- ledge acquired by it to those who had it not. They could not, indeed, convey to the blind any distinct notion of the manner in which they acquired this knowledge. A ball and socket would seem, to a blind man, in this case, as improper an instru- ment for acquiring such a variety and ex- tent of knowledge, as a dream or a vision. The manner in which a man who sees, discerns so many things by means of the eye, is as unintelligible to the blind, as (he manner in which a man may be inspired with knowledge by the Almighty, is to us. Ought the blind man, therefore, with- out examination, to treat all pretences to the gift of seeing as imposture ? Might he not, if he were candid and tractable, find reasonable evidence of the reality of this gift in others, and draw great advantages from it to himself ? The distinction we have made between the visible appearances of the objects of sight, and things suggested by them, is ne- cessary to give us a just notion of the in- tention of nature in giving us eyes. If we attend duly to (he operation of our mind OF SEEING. 133 tn the use of this faculty, we shall perceive that the visible appearance of objects is hardly ever regarded by us. It is not at all made an object of thought or reflec- tion, but serves only as a sign to introduce to the mind something else, which may be distinctly conceived bythose who neversaw. Thus, the visible appearance of things in my room varies almost every hour, accord- ing as the day is clear or cloudy, as the sun is in the east, or south, or west, and as my eye is in one part of the room or in an- other ; but I never think of these variations, otherwise than as signs of morning, noon, or night, of a clear or cloudy sky. A book or a chair has a different appearance to the eye, in every different distance and posi- tion ; yet we conceive it to be still the same ; and, overlooking the appearance, we immediately conceive the real figure, dis- tance, and posiiion of the body, of which its visible or perspective appearance is a sign and indication. When I see a man at the distance of ten yards, and afterwards see him at the dis- tance of a hundred yards, his visible ap- pearance, in its length, breadth, and all its linear proportions, is ten times less in the last case than it is in the first ; yet I do not conceive him one inch diminished by this diminution of his visible figure. Nay, I do not in the least attend to this diminution, even when I draw from it the conclusion of his being at a greater distance. For such is the subtilty of the mind's operation in this case, that we draw the conclusion, with- out perceiving that ever the premises en- tered into the mind. A thousand such in- stances might be produced, in order to shew that the visible appearances of objects are intended by nature only as signs or indica- tions ; and that the mind passes instantly to the things signified, without making the least reflection upon the sign, or even per- ceiving that there is any such thing. It is in a way somewhat similar, that the sounds of a language, after it is become familiar, are overlooked, and we attend only to the things signified by them. It is therefore a just and important ob- servation of the Bishop of Cloyne, That the visible appearance of objects is a kind of language used by nature, to inform us of their distance, magnitude, and figure. And this observation hath been very happily applied by that ingenious writer, to the solution of somepheenomena in optics, which had before perplexed the greatest masters in that science. ' The same observation is further improved by thejudicious Dr Smith, in his Optics, for explaining the apparent figure of the heavens, and the apparent distances and magnitudes of objects seen with glasses, or by the naked eye. Avoiding as much as possible the repe- tition of what hath been said by these ex- cellent writers, we shall avail ourselves of the distinction between the signs that nature useth in this visual language, and the things signified by them : and in what remains to be said of sight, shall first make some ob- servations upon the signs. Section III. OF THE VISIBLE APPEARANCES OF OBJECTS. In this section we must speak of things which are never made the object of re- flection, though almost every moment pre- sented to the mind. Nature intended them only for signs ; and in the whole course of life they are put to no other use. The mind has acquired a confirmed and invet- erate habit of inattention to them ; for they no sooner appear, than quick as light- ning the thing signified succeeds, and en- grosses all our regard. They have no name in language ; and, although we are conscious of them when they pass through the mind, yet their passage is so quick and so familiar, that it is absolutely un- heeded; nor do they leave any footsteps of themselves, either in the memory or imagination. That this is the case with regard to the sensations of touch, hath been shewn in the last chapter; and it holds no less with regard to the visible appear- ances of objects. I cannot therefore entertain the hope of being intelligible to those readers who have not, by pains and practice, acquired the habit of distinguishing the appearance of objects to the eye, from the judgment which we form by sight of their colour, distance, magnitude, and figure. The only profes- sion in life wherein it is necessary to make this distinction, is that of paintini.'. The painter hath occasion for an abstraction, with regard to visible objects, somewhat similar to that which we here require : and this indeed is the most difficult part of his art. For it is evident, that, if he could fix in his imagination the visible appearance of objects, without confounding it with the things signified by that appearance, it would be as easy for him to paint from the life, and to give every figure its proper shading and relief, and its perspective pro- portions, as it is to paint from a copy. Per- spective, shading, giving relief, and colour- ing, are nothing else but copying the ap- pearance which things make to the eye. We may therefore borrow some light on thesubjectofvisibleappearancefromthisart. Let one look upon any familiar object, such as a book, at different distances and in different positions : is he not able to affirm, upon the tcst'mony of his sight, that 136 OF THE HUMAN MIND it is the same bonk, the same object, whether seen at the distance of one foot or of ten, whether in one position or another ; that the colour is the same, the dimensions the same, and the figure the same, as far as the eye can judge ? This surely must be acknowledged. The same individual object is presented to the mind, only placed at different distances and in different posi- tions. Let me ask, in the next place, Whether this object has the same appear- ance to the eye in these different distances ? Infallibly it hath not. Kor, First, However certain our judgment may be that the colour is the same, it is as certain that it hath not the same appear- ance at different distances. There is a certain degradation of the colour, and a certain confusion and indistinctness of the minute parts, which is the natural conse- quence of the removal of the object to a greater distance. Those that are not painters, or critics in painting, overlook this ; and cannot easily be persuaded, that the colour of the same object hath a dif- ferent appearance at the distance of one foot and of ten, in the shade and in the light. But the masters in painting know how, by the degradation of the colour and the confusion of the minute parts, figures which are upon the same canvass, and at the same distance from the eye, may be made to represent objects which are at the most unequal distances. They know how to make the objects appear to be of the same colour, by making their pictures really of different colours, according to their distances or shades. Secondly, Every one who is acquainted with the rules of perspective, knows that the appearance of the figure of the book must vary in every different position : yet if you ask a man that has no notion of perspective, whether the figure of it does not appear to his eye to be the same in all its different positions ? he can with a good conscience affirm that it does. He hath learned to make allowance for the variety of visible figure arising from the difference of position, and to draw the proper con- elusions from it. But he draws these con- clusions so readily and habitually, as to lose sight of the premises : and therefore where he hath made the same conclusion, he con- ceives the visible appearance must have been the same. Thirdly, Let us consider the apparent magnitude or dimensions of the book. Whether I view it at the distance of one foot or of ten feet, it seems to be about seven inches long, five broad, and one thick. I can judge of these dimensions very nearly by the eye, and I judge them to be the same at both distances. But yet it is certain, th:it, at the distance of one foot, its visible length and breadth is about ten times as great as at the distance of ten feet ; and consequently its surface is about a hundred times as great. This great change of apparent magnitude is altogether overlooked, and every man is apt to im- agine, that it appears to the eye of the same size at both distances. Further, when 1 look at the book, it seems plainly to have three dimensions, of length, breadth, and thickness : but it is certain that the visible appearance hath no more than two, and can be exactly represented upon a canvass which hath only length and breadth. In the last place, does not every man, by sight, perceive the distance of the book from his eye ? Can he not affirm with certainty, that in one case it is not above one foot distant, that in another it is ten ? Nevertheless, it appears certain, that dis- tance from the eye is no immediate object of sight. There are certain things in the visible appearance, which are signs of dis- tance from the eye, and from which, as we shall afterwards shew, we learn by experi- ence to judge of that distance within cer- tain limits ; but it seems beyond doubt, that a man born blind, and suddenly made to see, could form no judgment at first of the distance of the objects which he saw. The young man couched by Cheselden thought, at first, that everything he saw touched his eye,* and learned only by ex- perience to judge of the distance of visible objects. I have entered into this long detail, in order to shew that the visible appearance of an object is extremely different from the notion of it which experience teaches us to form by sight ; and to enable the reader to attend to the visible appearance of colour, figure, and extension, in visible things, which is no common object of thought, but must be carefully attended to by those who would enter into the philosophy of this sense, or would comprehend what shall be said upon it. To a man newly made to see, the visible appearance of objects would be the same as to us ; but he would see nothing at all of their real dimensions, as we do. He could form no conjecture, by means of his sight only, bow many inches or feet they were in length", breadth, or thickness. He could perceive little or no- thing of their real figure ; nor could hedis« cern that this was a cube, that a sphere ; that this was a cone, and that a cylinder.-|- * Still they appeared external to the eye. — H. f l his is a misinterpretation of Cheselden, on whose authority this statement is made; though it must be confessed that the mode in which the case of the young man, couched by that distinguished sur- fteon, is report d, no s not merit all the eulngia that have been lavished on it. ;t is at once imper. lect and indistinct. Thus, nn the point in questi<« • Cheselden says;— "He (the patient) kne ? n« the shape nt anything, • or uny one thing from a other. OF SEEING. 137 His eye could not inform him that this object was near, and that more remote. The habit of a man or of a woman, which appeared to us of one uniform colour, vari- ously folded and shaded, would present to his eye neither fold or shade, but variety of colour. In a word, his eyes, though ever so perfect, would at first give him almost no information of things without him. They would indeed present the same appearances to him as they do to us, and speak the same language ; but to him it is an unknown language ; and, therefore, he would attend only to the signs, without knowing the sig- nification of them, whereas to us it is a lan- guage perfectly familiar ; and, therefore, we take no notice of the signs, but attend only to the thing signified by them. Section IV. THAT COLOUR IS A QUALITY OF BODIES, NOT A SENSATION OF THE MIND. By colour, all men, who have not been tutored by modern philosophy, understand, not a sensation of the mind, which can have no existence when it is not perceived, but a quality or modification of bodies, which continues to be the same whether it is seen or not. The scarlet-rose which is before me, is still a scarlet-rose when I shut my however different In shape or magnitude; bu\ upon being told what things were, whose form he before knew from feeling, he would carefully observe, that he might know them again ; but, > aving too many objects to learn at once, he forgot many of them, and (as he said) at first he learned to know, and again forgot a thousand things in a day. One particular only, though it may appear trifling, I will relate: Having often forgot which whs the vat and which the dog, he was ashamed to ask ; but, catching the rat, which he knew by feeling, he was observed to look at her steadfastly, and then, setiing her down, *aid, *So, puss! I shall know yuu another time.'" Here, when Cheselden says, " that his patient, u hen iccently couched, knew not the shape of any thing, nor anyone thing from another," &c , this cannot mean that he saw no difference between objects of different shapes and sizes; for, if this inter- pretation were adopted, the rest <>i tie statement beromes nonsense. If he had been altogether in ca- llable of apprehending differences, it could not be said that, " being told what things were whose form he before knew from feeling, he would carefully observe, that he might know them again;" for ob- servation supposes the power of discrimination, and, in particular, the anecdote of ihedog and cat would be inconceivable on that hypothesis. It is plain that Cheselden only meant to say, that the things which the patient could previously distinguish and deno- mina-eby touch, he could not now identity :md refer ti> their appellations by sight Ami this is what we might, a priori, be assured of. A sphere and a cube would certainly make different impressions on him j but it is probable that he could not assign to each its name, though, in this particular cas-, there is gnod ground for holding that the slightest consideration would enable a person, previously acquainted with these figures, and aware that the one was a cube and the other a sphere, to connect them with his anterior experience, and to discriminate them by name,— See Fhilos. Trans., I "28, nu. 102.— H. eyes, and was so at midnight when no eye saw it. The colour remains when the appearance ceases ; it remains the same when the appearance changes. For when I view this scarlet-rose through a pair of green spectacles, the appearance is changed ; but I do not conceive the colour of the rose changed. To a person in the jaundice, it has still another appearance ; but he is easily convinced that the change is in his eye, and not in the colour of the object. Every different degree of light makes it have a different appearance, and total dark- ness takes away all appearance, but makes not the least change in the colour of the body. We may, by a variety of optical experiments, change the appearance of figure and magnitude in a body, as well as that of colour; we may make one body appear to be ten. But all men believe, that, as a multiplying glass does not really produce ten guineas out of one, nor a mi- croscope turn a guinea into a ten-pound piece, so neither does a coloured glass change the real colour of the object seen through it, when it changes the appearance of that colour. The common language of mankind shews evidently, that we ought to distinguish be- tween the colour of a body, which is con- ceived to be a fixed and permanent quality in the body, and the appearance of that colour to the eve, which may be varied a thousand ways, by a variation of the light, of the medium, or of the eye itself. The permanent colour of the body is the cause which, by the mediation of various kinds or degrees of light, and of various transparent bodies interposed, produces all this variety of appearances. When a coloured body is presented, there is » certain apparition to the eye, or to the mind, which we have called the appearance of colt-ur, Mr Locke calls it an idea ; and, indeed, it may be called so with the greatest propriety. This idea can have no existence but when it is perceived. It is a kind of thought, and can only be the act of a percipient or thinking being. By the constitution of our nature, we are led to conceive this idea as a sign of something external, and are impatient till we learn its meaning. A thousand experi- ments for this purpose are made every day by children, even before they come to the use of reason. They look at things, they handle them, they put them in various po- sitions, at different distances, and in differ- ent lights. The ideas of sight, by these means, come to be associated with, and readily to suggest, things external, and al- together unlike them. In particular, that idea which we have called the appearance of colour, suggests the conception and belief of some unknown quality in the body which occasions the idea ; and it is to this quality, 138 OF THE HUMAN MIND and not to the idea, that we give the name of colour.* The various colours, although in their nature equally unknown, are easily distinguished when we think or speak of them, by being associated with the ideas which they excite. In like manner, gravity, magnetism, and electricity, although all unknown qualities, are distinguished by their different effects. As we grow up, the mind acquires a habit of passing so rapidly from the ideas of sight to the external tilings suggested by them, that the ideas are not in the least attended to, nor have they names given them in common language. When we think or speak of any parti- cular colour, however simple the notion may seem to be which is presented to the imagin- ation, it is really in some sort compounded. 1 1 involves an unknown cause and a known effect. The name of colour belongs indeed to the cause only, and not to the effect. But, as the cause is unknown, we can form no distinct conception of it but by its relation to the known effect ; and, therefore, both go to- gether in the imagination, and are so closely united, that they are mistaken for one simple object of thought. +■ When I would conceive those colours of bodies whkh we call scarlet and blne—\i I conceived them only as un- known qualities, I could perceive no distinc- tion between the one and the other. I must, therefore, for the sake of distinction, join to each of them, in my imagination, some effect or some relation that is peculiar ; and the most obvious distinction is, the appear- ance which one and the other makes to the eye. Hence the appearance is, in the imagin- ation, so closely united with the quality called a scarlet-colour , that they are apt to be mistaken for one and the same thing, although they are in reality so different and so unlike, that one is an idea in the mind, the other is a quality of body. I conclude, then, that colour is not a sensation, but a secondary quality of bodies, in the sense we have already explained; that it is a certain power or virtue in bodies, that in fair daylight exhibits to the eye an appearance which is very familiar to us, although it hath no name. Colour differs from other secondary qualities in this, that, whereas the name of the qualityis sometimes given to the sensation which indicates it, and is occasioned by it, we never, as far as I can judge, give the name of colour to the sens- ation, but to the quality only.J Perhaps *+t It is justly observed by Mr Stewart, that Ihp.-e p oerning both classes ol philosophers are vague and nu-orreit. Ihe Intter, in general, only allowed sjiecifs for two sonars, Sight a> <1 Hearing ; few admitted them in Feeling ; and j some rejected the.n altogether. — H. 140 OF THE HUMAN MIND. We desire, therefore, with pleasure, to do justice to the doctrine of Locke, and other modern philosophers, with regard to colour and other secondary qualities, and to ascribe to it its due merit, while we beg leave to censure the language in which they have expressed their doctrine. When they had explained and established the dis- tinction between the appearance which co- lour makes to the eye, and the modifica- tion of the coloured body which, by the laws of nature, causes that appearance, the question was, whether to give the name of colour to the cause or to the ef- fect ? By giving it, as they have done, to the effect, they set philosophy apparently in opposition to common sense, and expose it to the ridicule of the vulgar. But had they given the name of colour to the cause, as they ought to have done, they must then have affirmed, with the vulgar, that colour is a quality of bodies ; and that there is neither colour nor anything like it in the mind. Their language, as well as their sentiments, would have been per- fectly agreeable to the common apprehen- sions of mankind, and true Philosophy would have joined hands with Common Sense. As Locke was no enemy to common sense, it may be presumed, that, in this instance, as in some others, he was seduced by some received hypothesis ; and that this was ac- tually the case, will appear in the following section. Section VI. THAT NONE OF OUR SENSATIONS ARE RE- SEMBLANCES OF ANY OF THE QUALITIES OF BODIES. A second inference is, that, although co- lour is really a quality of body, yet it is not represented to the mind by an idea or sensation that resembles it ; on the con- trary, it is suggested by an idea which does not in the least resemble it. And this in- ference is applicable, not to colour only, but to all the qualities of body which we have examined. It deserves to be remarked, that, in the analysis we have hitherto given of the ope- rations of the five seuses, and of the quali- ties of bodies discovered by them, no in- stance hath occurred, either of any sensation which resembles any quality of body, or of any quality of body whose image or resem- blance is conveyed to the mind by means of the senses. There is no phsenomenon in nature more unaccountable than the intercourse that is carried on between the mind and the ex- ter ,al world — there is no phsenomenon which philosophical spirits have shewn greater avidity to pry into, arid to resolve. It is agreed by all, that this intercourse is carried on by means of the senses ; and this satisfies the vulgar curiosity, but not the philosophic. Philosophers must have some system, some hypothesis, that shews the manner in which our senses make us acquainted with external things. All the fertility of human invention seems to have produced only one hypothesis for this pur- pose, which, therefore, hath been univer- sally received ; and that is, that the mind, like a mirror, receives the images of things from without, by means of the senses ; so that their usemustbeto convey these images into the mind. • Whether to these images of external things in the mind, we give the name of sensible forms , or sensible species, with the Peripatetics, or the name of ideas of sensa- tion, with Locke ; or whether, with later philosophers, we distinguish sensations, which are immediately conveyed by the senses, from idtas of sensation, which are faint copies of our sensations retained in the memory and imagination ;-|- these are only differences about words. The hypo- thesis I have mentioned is common to all these different systems. The necessary and allowed consequence of this hypothesis is, that no material thing, nor any quality of material things, can be conceived by us, or made an object oj thought, until its image is conveyed to the mind by means of the senses. We shall examine this hypothesis particularly after- wards, and at this time only observe, that, in consequence of it, one would naturally expect, that to every quality and attribute uf body we know nr can conceive, there should be a sensation corresponding, which is the image. and resemblance of that qua- lity ; and that the sensations which have no similitude or resemblance to body, or to any of its qualities, should give us no con- ception of a material world, or of anything belonging to it. These things might be ex- pected as the natural consequences of the hypothesis we have mentioned. Now, we have considered, in this and the preceding chapters, Extension, Figure, Solidity, Motion, Hardness, Roughness, as well as Colour, Heat, and Cold, Sound, Taste, and Smell. We have endeavoured to shew that our nature and constitution lead us to conceive these as qualities of body, as all mankind have always con- * This is incorrect, especially as it asserts that the one universal hypothesis of philosophy was, that "the mind receives the images of things from with- out," meaning by these images, immediate or repre. senrarive objects, different from the modifications of the thinking subject itself. — H. + He refers to Hume: Aristotle, however, and Hoboes, had previously called Imagination a rfe.aV- inff sense, — H. ~ " 3 OF SEEING. 141 oeived them to be. We have likewise exa- mined with great attention the various sensations we have by means of the five senses, and are not able to find among them all one single* image of body, or of any of its qualities. From whence, then, come those images of body and of its qua- lities into the mind ? Let philosophers re- solve this question. All I can say is, that they come not by the senses. I am sure that, by proper attention and care, I may know my sensations, and be able to affirm with certainty what they resemble, and what they do not resemble. I have examined them one by one, and compared them with matter and its qualities ; and I cannot find one of them that confesses a resembling feature. A truth so evident as this — that our sens- ations are not images of matter, or of any of its qualities — ought not to yield to a hy- pothesis such as that above-mentioned, how- ever ancient, or however universally re- ceived by philosophers ; nor can there be any amicable union between the two. This will appear by some reflections upon the spirit of the ancient and modern philosophy concerning sensation. During the reign of the Peripatetic phi- losophy, our sensations were not minutely or accurately examined. The attention of philosophers, as well as of the vulgar, was turned to the things signified by them : therefore, in consequence of the common hypothesis, it was taken for granted, that all the sensations we have from external things, are the forms or images of these external things. And thus the truth we have mentioned yielded entirely to the hypo- thesis, and was altogether suppressed by it. Des Cartes gave » noble example of turning our attention inward, and scruti- nizing our sensations ; and this example hath been very worthily followed by mo- dern philosophers, particularly by Male- branche, Locke, Berkeley, and Hume. The effect of this scrutiny hath been, a gradual discovery of the truth above-mentioned — to wit, the dissimilitude between the sensa- tions of our minds, and the qualities or attributes of an insentient inert substance, such as we conceive matter to be. But this valuable and useful discovery, in its different stages, hath still been unhappily united to the ancient hypothesis — and from this inauspicious match of opinions, so unfriendly and discordant in their natures, have arisen those monsters of paradox and scepticism with which the modern philoso- phy is too justly chargeable. Locke saw clearly, and proved incon- testably, that the sensations we have by taste, smell, and hearing, as well .as the ' One tingle — a common but faulty pleonasm. — H. sensations of colour, heat, and cold, are nut resemblances of anything^ in bodies ; and in this he agrees with Des Cartes and Malebranche. Joining this opinion with the hypothesis, it follows necessarily, that three senses of the five are cut off from giving us any intelligence of the material world, as being altogether inept for that office. Smell, and taste, and sound, as well as colour and heat, can have no more rela- tion to body, than anger or gratitude ; nor ought the former to be called qualities of body, whether primary or secondary, any more than the latter. For it was natural and obvious to argue thus from that hypo- thesis : If heat, and colour, and sound are real qualities of body, the sensations by which we perceive them must be re- semblances of those qualities ; but these sensations are not resemblances ; there- fore, those are not real qualities of body. We see, then, that Locke, having found that the ideas of secondary qualities are no resemblances, was compelled, by a hypo- thesis common to all philosophers, to deny that they are real qualities of body. It is more difficult to assign a reason why, after this, he should call them secondary qualities ; for this name, if I mistake not, was of his invention.* Surely he did not mean that they were secondary qualities of the mind ; and I do not see with what pro- priety, or even by what tolerable license, he could call them secondary qualities of body, after finding that they were no qua- lities of body at all. In this, he seems to have sacrificed to Common Sense, and to have been led by her authority even in opposition to his hypothesis. The same sovereign mistress of our opinions that led this philosopher to call those things second- ary qualities of body, which, according to his principles and reasonings, were no qualities of body at all, hath led, not the vulgar of all ages only, but philosophers also, and even the disciples of Locke, to believe them to be real qualities of body — she hath led them to investigate, by experiments, the nature of colour, and sound, and heat, in bodies- Nor hath this investigation been fruitless, as it must have been if there had been no such thing in bodies ; on the con- trary, it hath produced very noble and useful discoveries, which make a very con- siderable part of natural philosophy. If, then, natural philosophy be not a dream, there is something in bodies which we call colour, and heat, and sound. And if this be so, the hypothesis from which the con- • The terms First anrl Second, or Primary and Secondary qualities, were no more an invention of Locke than the distinction which he applied them to denote. The terms First and Second Qualities, as I have noticed, in the Aristotelian philosophy, marked out, however, a different distribution ox qualities than that in question.— H. 142 OF THE HUMAN MIND. trary is concluded, must be false : for the argument, leading; to a false conclusion, recoils against the hypothesis from which it was drawn, and thus directs its force backward. If the qualities of body were known to us only by sensations that resem- ble them, then colour, and sound, and heat could be no qualities of body ; but these are real qualities of body ; and, there- fore, the qualities of botty are not known only by means of sensations that resemble them. But to proceed. What Locke had proved with regard to the sensations we have by smell, taste, and hearing, Bishop Berkeley proved no less unanswerably with regard to all our other sensations ;* to wit, that none of them can in the least resemble the qualities of a lifeless and insentient being, such as matter is conceived to be. Mr Hume hath confirmed this by his authority and reasoning. This opinion surely looks with a very malign aspect upon the old hypo- thesis ; yet that hypothesis hath still been retained, and conjoined with it. And what a brood of monsters hath this produced ! The first-born of this union, and, per- haps, the most harmless, was, That the secondary qualities of body were mere sens- ations of the mind. To pass by Male- branche's notion of seeing all things in the ideas of the divine mind,-|- as a foreigner, never naturalized in this island ; the next was Berke'ey's system, That extension, and figure, and hardness, and motion — that land, and sea, and houses, and our own bodies, as well as those of our wives, and children, and friends — are nothing but ideas of the mind : and that there is nothing existing in nature, but minds and ideas. The progeny that followed, is still more frightful ; so that it is surprising, that one could be found who had the courage to act the midwife, to rear it up, and to usher it into the world. No causes nor effects ; no substances, material or spiritual ; no evi- dence, even in mathematical demonstration ; no liberty nor active power ; nothing exist- ing in nature, but impressions and ideas following each other, without time, place, or subject. Surely no age ever produced such a system of opinions, justly deduced with great acuteness, perspicuity, and ele- gance, from a principle universally received. * Bayle, before Berkeley, shewed that the reason. ing of Malebranche against the external reality of the secondary qualities, when carried to its legitimate issue, subverted also that of the primary.— H, t Malebranche, it should bo observed, distin- guished more precisely than Des Cartes, or any pre- vious philosopher, primary from secondary quali- ties; and perception {idee) from sensation (senti- ment.") He regarded the sensation of the secondary qualities as the mere subjective feeling which the human mind had of its own affections ; but I he per- ception of the primary he considered as an objective rntuition it obtained of these, as represented in the divine mind — H. The hypothesis we have mentioned is the father of them all. The dissimilitude of our sensations and feelings to external things, is the innocent mother of most of them. As it happens sometimes, in an arith- metical operation, that two errors balance one another, so that the conclusion is little or nothing affected by them ; but when one of them is corrected, and the other left, we are led farther from the truth than by both together : so it seems to have happened in the Peripatetic philosophy of sensation, compared with the modern. The Peripa- tetics adopted two errors ; but the last served as a corrective to the first, and ren- dered it mild and gentle ; so that their system had no tendency to scepticism. The moderns have retained the first of those errors, but have gradually detected and corrected the last. The consequence hath been, that the light we have struck out hath created darkness, and scepticism hath ad- vanced hand in hand with knowledge, spreading its melancholy gloom, first over the material world, and at last over the whole face of nature. Such a phaenomeno n as this, is apt to stagger even the lovers of light and knowledge, while its cause is latent ; but, when that is detected, it may give hopes that this darkness shall not be everlasting, but that it shall be succeeded by a more permanent light. Section VII. OP VISIBLE FIGURE AND EXTENSION. Although there is no resemblance, nnr, as far as we know, any necessary connec- tion, between that quality in a body which we call its colour, and the appearance which that colour makes to the eye, it is quite otherwise with regard to its figure and mag- nitude. There is certainly a resemblance, and a necessary connection, between the visible figure and magnitude of a body, and its real figure and magnitude ; no man can give a reason why a scarlet colour affects the eye in the manner it does ; no man can be sure that it affects his eye in the same manner as it affects the eye of another, and that it has the same appearance to him as it has to another man ; — but we can assign a reason why a circle placed obliquely to the eye, should appear in the form of an ellipse. The visible figure, magnitude, and position may, by mathematical reasoning, be deduced from the real ; and it may be demonstrated, that every eye that sees dis- tinctly and perfectly, must, in the same situation, see it under this form, and no other. Nay, we may venture to affirm, that a man born blind, if he were instructed in mathematics would be able to determine OF SEEING. 143 tlie visible figure of a body, when its real figure, distance, and position, are given. Dr Saunderson understood the projection of the sphere, and perspective. Now, I require no more knowledge in a blind man, in order to his being able to determine the visible fig re of bodies, than that he can project the outline of a given body, upon the surface of a hollow sphere, whose centre is in the eye. This projection is the visible figure he wants : for it is the same figure with that which is projected upon the tunica retina in vision. A blind man can conceive lines drawn from every point of the object to the centre of the eye, making angles. He can con- ceive that the length of the object will appear greater or less, in proportion to the angle which it subtends at the eye; and that, in like manner, the breadth, and in general the distance, of any one point of the object from any other point, will appear greater or less, in proportion to the angles which those- distances subtend. He can easily be made to conceive, that the visible appearance has no thickness, any more than a projection of the sphere, or a perspective draught. He may be informed, that the eye, until it is aided by experience, does not represent one object as nearer or more remote than another. Indeed, he would probably conjecture this of himself, and be apt to think that the rays of light must make the same impression upon the eye, whether they come from a greater or a less distance. These are all the principles which we suppose our blind mathematician to have ; and these he may certainly acquire by in- formation and reflection. It is no less certain, that, from these principles, having given the real figure and magnitude of a body, and its position and distance with regard to the eye, he can find out its visible figure and magnitude. He can demonstrate in general, from these principles, that the visible figure of all bodies will be the same with that of their projection upon the sur- face of a hollow sphere, when the eye is placed in the centre. And he can demon- strate that their visible magnitude will be greater or less, according as their projec- tion occupies a greater or less part of the surface of this sphere. To set this matter in another light, let us distinguish betwixt the position of objects with regard to the eye, and their distance from it. Objects that lie in the same right line drawn from the centre of the eye, have the same position, however different their distances from the eye may be : but objects which lie in different right lines drawn from the eye's centre, have a different position ; i na this difference of position is greater or less i.i proportion to the angle made at the eye by the right lines mentioned. Having thus defined what we mean by the position of objects with regard to the eye, it is evi- dent that, as the real figure of a body con- sists in the situation of its several parts with regard to one another, so its visible figure consists in the position of its several parts with regard to the eye ; and, as ho that hath a distinct conception of the situ- ation of the parts of the body with regard to one another, must have a distinct con- ception of its real figure ; so he that con- ceives distinctly the position of its several parts with regard to the eye, must have a distinct conception of its visible figure. Now, there is nothing, surely, to hinder a blind man from conceiving- the position of the several parts of a body with regard to the eye, any more than from conceiving their situation with regard to one another ; and, therefore, I conclude, that a blind man may attain a distinct conception of the vis- ible figure of bodies.* Although we think the arguments that have been offered are sufficient to prove that a blind man may conceive the visible extension and figure of bodies ; yet, in order to remove some prejudicesagainstthis truth, it will be of use to compare the notion which a blind mathematician might form to him- self of visible figure, with that which is pre- sented to the eye in vision, and to observe wherein they differ. First, Visible figure is never presented to the eye but in conjunction with colour : and, although there be no connection be- tween them from the nature of the things, yet, having so invariably kept company to- gether, we are hardly able to disjoin them even in our imagination. \ What mightily increases this difficulty is, that we have never been accustomed to make visible figure an object of thought. It is only used as a sign, and, having served this purpose, passes away, without leaving a trace behind. The drawer or designer, whose business it is to hunt this fugitive form, and to take a copy of it, finds how difficult his task is, after many years' labour and practice. Happy ! if at last he can acquire the art of arresting it in his imagination, until he can delineate it. For then it is evident that he must be able to draw as accurately from the life as from a copy. But how few of the professed masters of designing are ever able to arrive at this degree of perfec- tion ! It is no wonder, then, that we should find so great difficulty in conceiving this form apart from its constant associate, * The most accurate observations of the blind from birth evince, however, that their conceptions of figure are extremely limited. — H. t In other words, that unextended colour can be perceived — can be imagined. Of this paradox (wh ch is also adopted by Mr Stewart) in the sequel — H. 144 OF THE HUMAN MIND. when it is so difficult to conceive it at ail- But our blind man's notion of visible figure will not be associated with colour, of which he hath no conception, but it will, perhaps, be associated with hardness or smoothness, with which he is acquainted by touch. These different associations are apt to impose upon us, and to make things seem different, which, in reality, are the same. Secondly, The blind man forms the no- tion of visible figure to himself, by thought, and by mathematical reasoning from prin- ciples ; whereas, the man that sees, has it presented to his eye at once, without any labour, without any reasoning, by a kind of inspiration. A man may form to himself the notion of a parabola, or a cycloid, from the mathematical definition of those figures, although he had never seen them drawn or delineated. Another, who knows nothing of the mathematical definition of the figures, may see them delineated on paper, or feel them cut out in wood. Each may have a distinct conception of the figures, one by mathematical reasoning, the other by sense. Now, the blind man forms his notion of visible figure in the same manner as the first of these formed his notion of a para- bola or a cycloid, which he never saw. Thirdly, Visible figure leads the man that sees, directly to the conception of the real figure, of which it is a sign. But the blind man's thoughts move in a contrary direction. For he must first know the real figure, distance, and situation of the body, and from thence he slowly traces out the visible figure by mathematical reasoning. Nor does his nature lead him to conceive this visible figure as a sign ; it is a creature of his own reason and imagination. Section VIII. SOME QUERIES CONCERNING VISIBLE FIGURE ANSWERED. It may be asked, What kind of thing is this visible figure ? Is it a Sensation, or an Idea ? If it is an idea, from what sensa- tion is it copied ? These questions may seem trivial or impertinent to one who does not know that there is a tribunal of inqui- sition erected by certain modern philoso- phers, before which everything in nature must answer. The articles of inquisition are few indeed, but very dreadful in their consequences. They are only these : Is the prisoner an Impression or an Idea ? If an idea, from what impression copied ? Now, if it appears that the prisoner is neither an impression, nor an idea copied from some impression, immediately, with- out being allowed to offer anything in arrest of judgment, he is sentenced to pass out of existence, and to be, in all time to come, an empty unmeaning sound, or the ghost of a departed entity. * Before this dreadful tribunal, cause and effect, time and place, matter and spirit, have been tried and cast : how then shall such a poor flimsy form as visible figure stand before it ? It must even plead guilty, and confess that it is neither an impression nor an idea. For, alas ! it is notorious, that it is extended in length and breadth ; it may be long or short, broad or narrow, triangular, quadrangular, or circular ; and, therefore, unless ideas and impressions are extended and figured, it cannot belong to that category. If it should still be asked, To what cate- gory of beings does visible figure then be- long ? I can only, in answer, give some tokens, by which those who are better ac- quainted with the categories, may chance to find its place- It is, as we have said, the position of the several parts of a figured body with regard to the eye. The dif- ferent positions of the several parts of the body with regard to the eye, \vhen put to- gether, make a real figure, which is truly extended in length and breadth, and which represents a figure that is extended in length, breadth, and thickness. In like manner, a projection of the sphere is a real figure, and hath length and breadth, but represents the sphere, which hath three dimensions. A projection of the sphere, or -a, perspective view of a palace, is a re- presentative in the very same sense as visi- ble figure is ; and wherever they have their lodgings in the categories, this will be found to dwell next door to them. It may farther be asked, Whether there be any sensation proper to visible figure, by which it is suggested in vision ? — or by what means it is presented to the mind ?+ » « Where Entity and Quiddity, The ghosts of defunct bodies, fly." Hi dibras.— H. f " In Dr Reid's ' Inquiry,*" (says Mr Stewart, in one of his last works, in reference to the following reasoning,) " he Has introduced a discussion con- cerning the perception of visible figure, which ha< puzzled me since the first time (more than forty years ago) that I read his'work. The discussion relates te thequestinn, ■ Whethertherebeanysensation propel to visible figure, by which it is suggested in vision?' The result ot the argument is, that * our eye might have been so framed as to suggest the figure of the object, without suggesting colour or any other quali- ty ; and, ot consequence, there seems to be no sensa- tion appropriated to visible figure ; thisijuality being suggested immediately by the material impression upon the organ, of which impression we are not conscious'— lnquiiy, &c chap. vi. $ 8. To my apprehension, nothing can appear more manifest than this, that, if there had been no variety in our sensations of colour, and, still more, if we had had no sensation of colour whatsoever, the organ of sight amid have given us no in ormation, cither with re- spect tojigures or to distances ; ano, of consequence, would have been as useless to us, as if we had i>ecn afflicted, from the moment of our birth, with a %utta seiena."—£)iisertatio?i t &c, p. G6, note ; 2d w£ OF SEEING. 145 Tins is a question of some importance, in order to our having a distinct notion of the faculty of seeing : and to give all the light to it we can, it is necessary to compare this sense with other senses, and to make some suppositions, by which we may be enabled to distinguish things that are apt to be con- founded, although they are totally dif- ferent. There are three of our senses which give us intelligence of things at a, distance :* smell, hearing, and sight. In smelling and <*n hearing, we have a sensation or impres- sion upon the mind, which, by our consti- tution, we conceive to be a sign of some- thing external : but the position of this external thing, with regard to the organ of sense, is not presented to the mind along with the sensation. When I hear the sound of a coach, I could not, previous to experience, determine whether the sounding body was above or below, to the right hand or to the left. So that the sensation, sug- gests to me some external object as the cause or occasion of it ; but it suggests not the position of that object, whether it lies in this direction or in that. The same thing may be said with regard to smelling. But the case is quite different with regard to seeing. When I see an object, the ap- pearance which the colour of it makes, may be called the sensation, which suggests to me some external thing as its cause ; but it suggests likewise the individual direction and position of this cause witfi regard to the eye. I know it is precisely in such a a direction, and in no other. At the same time, I am not conscious of anything that can be called sensation, but the sensation of colour. The position of the coloured thing is no sensation ; but it is by the laws of my constitution presented to the mind along with the colour, without any additional sensation. Let us suppose that the eye were so con- stituted that the rays coming from any one point of the object were not, as they are in our eyes, collected in one point of the retina, but diffused over the whole : it is evident to those who understand the struc- ture of the eye, that such an eye as we have supposed, would shew the colour of a body as our eyes do, but that it would neither shew figure nor position. The operation of such an eye would be precisely similar to that of hearing and smell ; it would give The questions concerning the mutual dependence of colour on extension, and of extension and figure on colour, in perception and imagination, cannot be dismissed in a foot-note. I shall endeavour, in Note E, to shew that we can neither see nor imagine colour apart from extension, nor extension and figure apart from colour.— H. * Properly speaking, nosen&e gives us a knowledge of aught hut what is in immediate contact with its organ. All else is something over and above percep- tion — H. no perception of figure or extension, but merely of colour. Nor is the supposition we have made altogether imaginary : for it is nearly the case of most people who have cataracts, whose crystalline, as Mr Chesel- den observes, does not altogether exclude the rays of light, but diffuses them over the retina, so that such persons see things as one does through a glass of broken gelly : they perceive the colour, but nothing of the figure or magnitude of objects.*" Again, if we should suppose that smell and sound were conveyed in right lines from the objects, and that every sensation of hearing and smell suggested the precise direction or position of its object ; in this case, the operations of hearing and smelling would be similar to that of seeing : we should smell and hear the figure of objects, in the same sense as now we see it ; and every smell and sound would be associated with some figure in the imagination, as colour is in our present state, -f- * Reid, as remarked by Mr Fearn, misinterprets Cheselden in founding on the expressions of this report, a proof of his own paradox, that-colour can possibly be an object of vision, apait from extension. There is no ground in that repot t for .such an inference ; for it contains absolutely nothing to in. validate, and much to support the doctrine — that, though sensations of colour may be experienced thiough the medium of an imperfect cataract, while the .figures of external objects are intercepted or broken down ; yet that, in these sensations, coloui being diffused over the retina, must appear to uu extended, and of an extension limited by the bound, aries of that sensitive membrane itself. The relative passage of Cheselden is as follows :— '* Though we say of the gentleman couched between thirteen And fourteen years of age, that he was blind, as we do of all people who have ripe cataracts, yet they are never so blind from that cause, but ihey can discern day from night, and for the most part in a strong light distinguish black, white, and scarlet; but the light by which these perceptions are made, being le^. in obliquely through the aqueous humour, or the anterior surface of the crystalline, by which the rays cannot be brought into a focus upon the retina, they can discern in no other manner than a sound eye can through a glass of broken jelly, where a great variety oi surfaces so differently refract the light, that the sevetal distinct pencils of rays cannot he collected by the eye into their proper foci, wherefore the shape nf an o jed in such a case cannot be at all disccn ed, though the colour may And thus it was with this young gentleman, who, though he knew these colours asunder in a good light, yet, when he saw them afrer he was couched, the faint ideas he had of them before, were not sufficient for him to know hem by after- wards, and therefore he did not think ihem the same which he had before known by those names " — There are also several statements in the repot t which shew that thepatieniwas, on the recovery of distinct vision, perfectly familiar with differences of visible magnitude Sec NoteE. — H. ■f To render this supposition possible, we mud not only change theobjective, but also the subjective conditions of smell and hearing; for, with our or- gans of these senses, and our nervous system in ge- neral, constituted as they are at present, the resul* would not be as a-sumed, even were the olfactory effluvia and audible vibrations convejed in right lines.from bodies to the nose and ear But to sup- pose both subjective and objective conditions than .. ed is to suppose new qualities and n^w senses altogether; an hypothesis which would hardly serve the ourposc of an illustration, a notiori. A similar hypothesis and illustration ii 'to be found in Condillac's " Trail e des Sensations;" but, L 146 OF THE HUMAN MIND. We have reason to believe, that the rays of light make some impression upon the retina; but we are not conscious of this impression ; nor have anatomists or philo- sophers been able to discover the nature and effects of it ; whether it produces a vibra- tion in the nerve, or the motion of some subtile fluid contained in the nerve, or some- thing different from either, to which we cannot give a name. Whatever it is, we shall call it the material impression ; remem- bering carefully, that it is not an impression upon the mind, but upon the body ; and that it is no sensation, nor can resemble sensation, any more than figure or motion can resemble thought. Now, this material impression, -made upon a particular point of the retina, by the laws ot our constitution, suggests two things to the mind — namely, the colour and the position of some exter- nal object. No man can give a reason why the same material impression might not have suggested sound, or smell, or either of these, along with the position of the object. That it should suggest colour and position, and nothing else, we can resolve only into our constitution, or the will of our Maker. And since there is no necessary connection between these two things suggested by this material impression, it might, if it had so pleased our Creator, have suggested one of them without the other. Let us suppose, therefore, since it plainly appears to be possible, that our eyes had been so framed as to suggest to us the position of the object, without suggesting colour, or any other quality : What is the consequence of this supposition ? It is evidently this, that the person endued with such an eye, would per- ceive the visible figure of bodies, without having any sensation or impression made upon his mind. The figure he perceives is altogether external ; and therefore cannot be called an impression upon the mind, without the grossest abuse of language. If it should be said, that it is impossible to perceive a figure, unless there be some im- pression of it upon the mind, I beg leave not to admit the impossibility of this without some proof : and I can find none. Neither can I conceive what is meant by an impres- sion of figure upon the mind. I can conceive an impression of figure upon wax, or upon any body that is fit to receive it ; but an impression of it upon the mind, is to me quite unintelligible ; and, although I form the most distinct conception of the figure, I cannot, upon the strictest examination, find any impression of it upon my mind. If wc suppose, last of all, that the eye hath the power restored of perceiving colour, as Mr Stewart observes, though thus anticipated, there is no ground for thinking that Reid was at all acquainted with the writings of the French phi- losopher. — H. I apprehend that it will be allowed, that now it perceives figure in the very same manner as before, with this difference only, that colour is always joined with it. In answer, therefore, to the question pro- posed, there seems to be no sensation thai is appropriated to visible figure, or whose office it is to suggest it. It seems to be suggested immediately by the material im- pression upon the organ, of which we are not conscious : and why may not a material impressioii upon the rethia suggest visible figure, as well as the material impression made upon the hand, when we grasp a ball, suggests real figure ? In the one case, one and the san.e material impression, suggests both colour and visible figure ; and in the other case, one and the same material im- pression suggests hardness, heat, or cold, and real figure, all at the same time. We shall conclude this section withan- other question upon this subject. Since the visible figure of bodies is a real and exter- nal object to the eye, as their tangible figure is to the touch, it may be asked, Whence arises the difficulty of attending to the first, and the facility of attending to the last ? It is certain that the first is more frequently presented to the eye, than the last is to the touch ; the first is as distinct and deter- minate an object as the last, and seems in its own nature as proper for speculation. Yet so little hath it been attended to, that it never had a name in any language, until Bishop Berkeley gave it that which we have used after his example, to distinguish it from the figure which is the object of touch. The difficulty of attending to the visible figure of bodies, and making it an object of thought, appears so similar to that which we find in attending to our sensations, that both have probably like causes. Nature intended the visible figure as a sign of the tangible figure and situation of bodies, and hath taught us, by a kind of instinct, to put it always to this use. Hence it happens, that the mind passes over it with a rapid motion, to attend to the things signified by it. It is as unnatural to the mind to stop at the visible figure, and attend to it, as it is to a spherical body to stop upon an in- clined plane. There is an inward principle, which constantly carries it forward, and which cannot be overcome but by a contrary force. There are other external things which- nature intended for signs ; and we find this common to them all. that the mind is disposed to overlook them, and to attend only to the things signified by them. Thus there are certain modifications of the hu- man face, which are natural signs of the present disposition of the mind. Every man understands the meaning of these signs, but not one of a hundred ever attended to OF SEEING 147 the signs themselves, or knows anything about them. Hence you may find many an excellent practical physiognomist who knows nothing of the proportions of a face, nor can delineate or describe the expression of any one passion. An excellent painter or statuary can tell, not only what are the proportions of a good face, but what changes every passion makes in it. This, however, is one of the chief mysteries of his art, to the acquisition of which infinite labour and attention, as well as a happy genius, are required ; but when he puts his art in practice, and happily ex- presses a passion by its proper signs, every one understands the meaning of these signs, without art, and without reflection. What has been said of painting, might easily be applied to all the fine arts. The difficulty in them all consists in knowing and attending to those natural signs where- of every man understands the meaning. We pass from the sign to the thing sig- nified, with ease, and by natural impulse ; but to go backward from the thing signi- fied to the sign, is a work of labour and difficulty. Visible figure, therefore, being intended by nature to be a sign, we pass on immediately to the thing signified, and can- not easily return to give any attention to the sign. Nothing shews more clearly our indis- position to attend to visible figure and vi- sible extension than this — that, although mathematical reasoning is no less appli- cable to them, than to tangible figure and extension, yet they have entirely escaped the notice of mathematicians. While that figure and that extension which are objects of touch, have been tortured ten thousand ways for twenty centuries, and a very noble system of science has been drawn out of them, not a single proposition do we find with regard to the figure and ex- tension which are the immediate objects of sight ! When the geometrician draws a diagram with the most perfect accuracy — when he keeps his eye fixed upon it, while he goes through a long process of reasoning, and demonstrates the relations of the several parts of his figure— he does not consider that the visible figure presented to his eye, is only the representative of a tangible figure, upon which all his attention is fixed ; he does not consider that these two figures have really different properties ; and that, what he demonstrates to be true of the one, is not true of the other. This, perhaps, will seem so great a para- dox, even to mathematicians, as to require demonstration before it can be believed. Nor is the demonstration at all difficult, if the reader will have patience to enter but a little into the mathematical consideration of visible figure, which we shall call t/i6 geometry ofvisibles. Section IX. or THE GEOMETRY OP VISIBLES.* In this geometry, thedefinitions of a point ; of a line, whether straight or curve ; of an angle, whether acute, or right, or obtuse ; and of a circle — are the same as in common geometry. The mathematical reader will easily enter into the whole mystery of this geometry, if he attends duly to these few evident principles. 1. Supposing the eye placed in the centre of a sphere, every great circle of the sphere will have the same appearance to the eye as if it was a straight line ; for the curva- ture of the circle being turned directly to- ward the eye, is not perceived by it. And, for the same reason, any line which is drawn in the plane of a great circle of the sphere, whether it be in reality straight or curve, will appear straight to the eye. 2. Every visible right line will appear to coincide with some great circle of the sphere ; and the circumference of that great circle, even when it is produced until it returns into itself, will appear to be a con- tinuation of the same visible right line, all the parts of it being visibly in directum. For the eye, perceiving only the position of o , bjects~witlr regartTftTitself , and not their dlstancepiviirsee those points in the same visible pla ce which have the same position witE'regard to the eye, how different soever theiFmstances from it maybe. Now, since a'plane'passing through the eye and a given visible right line, will be the plane of some great circle of the sphere, every point of the visible right line will have the same position as some point of the great circle ; therefore, they will both have the same visible place, and coincide to the eye; and the whole circumference of the great circle, continued even until 'it returns into itself, will appear to be a continuation of the same visible right line. Hence it follows — 3. That every visible right line, when it is continued in directum, as far as it may he continued, will be represented by a great circle of a sphere, in whose centre the eye is placed. It follows — 4. That the visible angle comprehended under two visible right lines, is equal to the spherical angle comprehended under the two great circles which are the representa- tives of these visible lines. For, since the visible lines appear to coincide with the * Mow does this differ from a doctrine of Perspec- tive ? — At any -ate. the notion is Berkeley's. Com. pare" New Theoiy of Vision," \i, 153— 159.— H. n3 148 OF THE HUMAN MIND. great circles, the visible angle compre- hended under the former must be equal to the visible angle comprehended under the latter. But the visible angle comprehended under the two great circles, when seen from the centre, is of the same magnitude with the spherical angle which they really com- prehend, as mathematicians know ; therej- ' fore, the visible angle made by any two visible lines is equal to the spherical angle- made by the two great circles of the sphere which are their representatives. 5. Hence it is evident, that every visible right-lined triangle will coincide in all its parts with some spherical triangle. The sides of the one will appear equal to the sides of the other, and the angles of the one to the angles of the other, each to each ; and, therefore, the whole of the one triangle will appear equal to the whole of the other. In ajvo_rd, to the eye they will be one and the same, and have the same mathematii properties. The properties, therefore, visible right-lined triangles are not the same with the properties of plain triangles, but are the same with those of spherical tri- angles. 6. Every lesser circle of the sphere will appear , a circle to the eye, placed, as we have supposed all along, in the centre of the sphere ; and, on the other hand, every visible circle will appear to coincide with some lesser circle of the sphere. 7. Moreover, the whole surface of the sphere will represent the whole of visible space ; for, since every visible point coin- cides with some point of the surface of the sphere, and has the same visible place, it follows, that all the parts of the spherical surface taken together, will represent all possible visible places — that is, the whole of visible space. And from this it follows, in the last place — 8. That every visible figure will be repre- sented by that part of the surface of the sphere on which it might be projected, the eye being in the centre. And every such visible figure will bear the same ratio to the whole of visible space, as the part of the spherical surface which represents it, bears to the whole spherical surface. The mathematical reader, I hope, will enter into these principles with perfect facility, and will as easily perceive that the following propositions with regard to visible figure and space, which we offer only as a specimen, may be mathematically demon- strated from them, and are not less true nor less evident than the propositions of Euclid, with regard to tangible figures. Prop. 1. Every right line being produced, will at last return into itself. 2. A right line, returning into itself, is the longest possible right line ; and all other right lines bear a finite ratio to it. 3. A right line returning into itself, divides the whole of visible space into two equal parts, which will both be compre- hended under this right line. 4. The whole of visible space bears a finite ratio to any part of it. 5. Any twj^g|d]Jinej_bejn^profliified, )vill TneefrTn two points, andmutually bisect each other • 6. If two lines be parallel — that is, every where equally distant from each other — they cannot both be straight. 7. Any right line being given, a point/ may be found, which is at the same dis- tance from all the points of the given right line. ' 8. A circle may be parallel to a right i line — that is, may be equally distant from I it in all its parts. ' 9. Right-lined triangles that are similar, are also equal. \ 10. Of every right-lined triangle, the / hree arjg'es taken together, are greater han two right angles. I 11. The angles of a right-lined triangle, may all be right angles, or all obtuse angles. 12. Unequal circles are not as the squares of their diameters, nor are their circumferences in the ratio of their dia- meters. This small specimen of the geometry of visibles, is intended to lead the reader to a clear and distinct conception of the figure and extension which is presented to the mind by vision ; and to demonstrate the truth of what we have affirmed above — namely, that those figures and that exten- sion which are the immediate objects of sight, are not the figures and the extension about which common geom etry is employed ; that the geometrician, while he looks at his diagram, and demonstrates a proposition, hath a figure presented to his eye, which is only a sign and representative of a tangible figure ; that he gives not the least atten- tion to the first, but attends only to the last ; and that these two figures have differ- ent properties, so that what he demon- strates of the one, is not true of the other. It deserves, however, to be remarked, that, as a small part of a spherical surface differs not sensibly from a plain surface, so a small part of visible extension differs very little from that extension in length and breadth, which is the object of touch. And it is likewise to be observed, that the human eye is so formed, that an object which is seen distinctly and at one view can occupy but a small part of visible space ; for we never see distinctly what is at a considerable distance from the axis of the eye ; and, therefore, when we would see a large object at one view, the eye must be at so great a distance, that the object OP SEEING. 149 occupies but a small part of visible space. From these two observations, it follows, that plain figures which are seen at one view, when their planes are not oblique, but direct to the eye, differ little from the visible figures which they present to the eye. The several lines in the tangible figure, have very nearly the same propor- tion to each other as in the visible ; and the angles of the one are very nearly, al- though not strictly and mathematically, equal to those of the other. Although, therefore, we have found many instances of natural signs which have no similitude to the things signified, this is not the case with regard to visible figure. It hath, in all cases, such a similitude to the thing signified by it, as a plan or profile hath to that which it represents ; and, in some cases, the sign and thing signified have to all sense the same figure and the same proportions. If we could find a, being endued with sight only, without any other external sense, and capable of reflecting and reasoning upon what he sees, the notions and phi- losophical speculations of such a being, might assist us in the difficult task of distinguishing the perceptions which we have purely by sight, from those which de- rive their origin from other senses. Let us suppose such a being, and conceive, as well as we can, what notion he would have of visible objects, and what conclu- sions he would deduce from them. We must not conceive him disposed by his con- stitution, as we are, -to consider the visi- ble appearance as a sign of something else : it is no sign to him, because there is no- thing signified by it ; and, therefore, we must suppose him as much disposed to attend to the visible figure and extension of bodies, as we are disposed to attend to their tangi- ble figure and extension. If various figures were presented to his sense, he might, without doubt, as they grow familiar, compare them together, and perceive wherein they agree, and wherein they differ. He might perceive visible ob- jects to have length and breadth, but could have no notion of a third dimension, any more than we can have of a fourth.* All visible objects would appear to be termi- nated by lines, straight or curve ; and ob- jects terminated by the same visible lines, would occupy the same place, and fill the same part of visible space. It would not be possible for him to conceive one object to be behind another, or one to be nearer, another more distant. To us, who conceive three dimensions, a line may be conceived straight ; or it may be conceived incurvated in one dimension, * This proceeds upon the supposition that our no. ion ot space is merely empirical. — H. and straight in another ; or, lastly, it may be incurvated in two dimensions. Suppose a line to be drawn upwards and downwards, its length makes one dimension, which we shall call upwards and downwards ; and there are two dimensions remaining, accord- ing to which it may be straight or curve. It may be bent to the right or to the left ; and, if it has no bending either to right or left, it is straight in this dimension. But supposing it straight in this dimension of right and left, there is still another dimen- sion remaining, in which it may be curve ; for it may be bent backwards or forwards. When we conceive a tangible straight line, we exclude curvature in either of these two dimensions : and as what is conceived to be excluded, must be conceived, as well as what is conceived to be included, it follows that all the three dimensions enter into our conception of a straight line. Its length is one dimension, its straightness in two other dimensions is included, or curvature in these two dimensions excluded, in the conception of it. The being we have supposed, having no conception of more than two dimensions, of which the length of a line is one, cannot possibly conceive it either straight or curve in more than one dimension ; so that, in his conception of a right line, curvature to the right hand or left is excluded ; but curva- ture backwards or forwards cannot be ex- cluded, because he neither hath, nor can have any conception of such curvature. Hence we see the reason that a line, which is straight to the eye, may return into itself ; for its being straight to the eye, implies only straightness in one dimension ; and a line which is straight in one dimension may, notwithstanding, be curve in another dimen- sion, and so may return into itself. To us, who conceive three dimensions, a surface is that which hath length and breadth, excluding thickness ; and a surface may be either plain in this third dimension, or it may be incurvated : so that the notion of a third dimension enters into our concep- tion of a surface ; for it is only by means of this third dimension that we can dis- tinguish surfaces into plain and curve sur- faces ; and neither one nor the other can be conceived without conceiving a third dimension. The being we have supposed, having no conception of a third dimension, his visible figures have length and breadth indeed; but thickness is neither included nor ex- cluded, being a thing of which he has no conception. And, therefore, visible figures, although they have length and breadth, as surfaces have, yet they are neither plain surfaces nor curve surfaces. For a curve surface implies curvature in a third dimen- ^ sion, and a plain surface implies the want 150 OF THE HUMAN MIND. of curvature in a third dimension ; and such a being can conceive neither of these, because he has no conception of a third dimension. Moreover, although he hath a distinct conception of the inclination of two lines which make an angle, yet he can neither conceive a plain angle nor a spher- ical angle. Even his notion of a point is somewhat less determined than ours. In the notion of a point, we exclude length, breadth, and thickness ; he excludes length and breadth, but cannot either exclude or include thickness, because he hath no con- ceptual of it. Having thus settled the notions which nich a being as we have supposed might form of mathematical points, lines, angles, Jind figures, it is easy to see, that, by com- paring these together, and reasoning about them, he might discover their relations, and form geometrical conclusions built upon self-evident principles. He might likewise, without- doubt, have the same notions of numbers as we have, and form a system of arithmetic. It is not material to say in what order he might proceed in such dis- coveries, or how much time and pains he might employ about them, but what such a being, by reason and ingenuity, without any materials of sensation but those of sight only, might discover. As it is more difficult to attend to a de- tail of possibilities than of facts, even of slender authority, I shall beg leave to give an extract from the travels of Johannes Rudolphus Anepigraphus, a Rosicrucian philosopher, who having, by deep study of the occult sciences, acquired the art of transporting himself to various sublunary re- gions, and of conversing with various orders of intelligences, in the course of his adven- tures became acquainted with an order of beings exactly such as I have supposed. How they communicate their sentiments to one another, and by what means he be- came acquainted with their language, and was initiated into their philosophy, as well as of many other particulars, which might have gratified the curiosity of his readers, and, perhaps, added credibility to his rela- tion, he hath not thought fit to inform us ; these being matters proper for adepts only to know. His account of their philosophy is as fol- lows : — " The Idomenians," saith he, " are many of them very ingenious, and much given to contemplation. In arithmetic, geometry, metaphysics, and physics, they have most elaborate systems. In the two latter, in- deed, they have had many disputes carried on with great subtilty, and are divided in- to various sects ; yet in the two former there hath been no less unanimity than among the human species. Their prinei- , pies relating to numbers and arithmetic, making allowance for their notation, differ in nothing from ours — but their geometry differs very considerably." As our author's account of the geometry of the Idomenians agrees in everything with the geometry of visibles, of which we have already given a specimen, we shall pass over it. He goes on thus : — " Colour, extension, and figure, are conceived to be the essential properties of body. A very considerable sect maintains, that colour is the essence of body. If there had been no colour, say they, there had been no percep- tion or sensation. Colour is all that we perceive, or can coneeive, that is peculiar to body ; extension and figure being modes common to body and to empty-space. And if we should suppose a body to be annihi- lated, colour is the only thing in it that can be annihilated ; for its place, and conse- quently the figure and extension of that place, must remain, and cannot be imagined not to exist. These philosophers hold space to be the place of all bodies, immoveable and indestructible, without figure, and similar in all its parts, incapable of increase or di- minution, yet not unmeasurable ; for every the least part of space bears a finite ratio to the whole. So that with them the whole extent of space is the common and natural measure of everything that hath length and breadth ; and the magnitude of every body and of every figure is expressed by its being such a part of the universe. In like manner, the common and natural measure of length is an infinite right line, which, as hath been before observed, returns into itself, and hath no limits, but bears a finite ratio to every other line. "As to their natural philosophy, it is now acknowledged by the wisest of them to have been for many ages in a very low state. The philosophers observing, that body can differ from another only in colour, figure, or magnitude, it was taken for granted, that all their particular qualities must arise from the various combinations of these their essential attributes ; and, therefore, it was looked upon as the end ot natural philosophy, to shew how the various combinations of these three .qualities in dif- ferent bodies produced all the phenomena of nature. It were endless to enumerate the various systems that were invented with this view, and the disputes that were car- ried on for ages ; the followers of every system exposing the weak sides of other systems, and palliating those of their own, with great art. " At last, some free and facetious spirits, wearied with eternal disputation, and the labour of patching and propping weak sys- tems, began to complain of the subtilty" of nature ; of the infinite 1 changes that bodies OF SEEING. 151 -ndergo in figure, colour, and magnitude ; and of the difficulty of accounting for these appearances— making this a pretence for giving up all inquiries into the causes of things, as vain and fruitless. " These wits had ample matter of mirth and ridicule in the systems of philosophers ; and, finding it an easier task to pull down than to build or support, and that every sect furnished them with arms and auxi- liaries to destroy another, they began to spread mightily, and went on with great success. Thus philosophy gave way to scep- ticism and irony, and those systems which had been the work of ages, and the admira- tion of the learned, became the jest of the vulgar : for even the vulgar readily took part in the triumph over a kind of learning which they had long suspected, because it produced nothing but wrangling and alter- ed, ion. The wits, having now acquired great reputation, and being flushed with success, began to think their triumph in- complete, until every pretence to know- ledge was overturned ; and accordingly began their attacks upon arithmetic, geo- metry, and even upon the common notions of untaught Idomenians. So difficult it hath always been," says our anthor, "for great conquerors to know where to stop. " In the meantime, natural philosophy began to rise from its ashes, under the direction of a person of great genius, who is looked upon as having had something in him above Idomenian nature. He observed, that the Idomenian faculties were certainly intended for contemplation, and that the works of nature were a nobler subject to exercise them upon, than the follies of sys- tems, or the errors of the learned ; and being sensible of the difficulty of finding out the causes of natural things, he proposed, by accurate observation of the phsenomena of nature, to find out the rules according to which they happen, without inquiring into the causes of those rules. In this he made considerable progress himself, and planned out much work for his followers, who call themselves inductive philosophers. The sceptics look with envy upon this rising sect y as eclipsing their reputation, and threatening to limit their empire ; but they are at a loss on what hand to attack it. The vulgar begin to reverence it as pro- ducing useful discoveries. " It is to be observed, that every Idome- nian firmly believes, that two or more bo- dies may exist in the same place. For this they have the testimony of sense, and they can no more doubt of it, than they can doubt whether they have any perception at all. They often see two bodies meet and coincide in the same place, and separate again, without having undergone any change in their sensible qualities hi thi i penetration. When two bodies meet, and occupy the same place, commonly one onlj appears in that place, and the other disap- pears. That which continues to appear is said to overcome, the other to be over- come." To this quality of bodies they gave a name, which our author tells us hath no word answering to it in any human lan- guage. And, therefore, after making a long apology, which I omit, he begs leave to call it the overcoming quality of bodies. He assures us, that "the speculations which had been raised about this single quality of bodies, and the hypotheses contrived to ac- count for it, were sufficient to fill many volumes. JNor have there been, fewer hy- potheses invented by their philosophers, to account for the changes of magnitude and figure; which, in most bodies that move, they perceive to be in a continual fluctua- ation. The founder of the inductive sect, be ieving it to be above the reach of Ido- menian faculties, to discover the real causes of these phsenomena, applied himself to find from observation, by what laws they are connected together ; and discovered many mathematical ratios and relations con- cerning the motions, magnitudes, figures, and overcoming quality of bodies, which constant experience confirms. But the op- posers of this sect choose rather to content themselves with feigned causes of these phsenomena, than to acknowledge the real laws whereby they are governed, which humble their pride, by being confessedly unaccountable." Thus far Johannes Eudolphus Anepigra- phus. Whether this Anepigraphus be the same who is recorded among the Greek alchemistical writers not yet published, by Borrichius, Fabricius, and others," I do not pretend to determine. The identity of their name, and the similitude of their studies, although no slight arguments, yet are not absolutely conclusive. Nor will I take upon me to judge of the narrative of this learned traveller, by the external marks of his credibility ; I shall confine myself to those which the crit cs call internal. It . would even be of small importance to in- quire, whether the Idomenians have a real, or only an ideal existence ; since this is disputed among the learned with regard to things with which we are more nearly con- nected. The important question is, whe- ther the account above given, is a just ac- count of their geometry and philosophy ? We have all the faculties which they * This is true ; the name is not imaginary "Anepigraphus the Philosopher'' is i he Tepuled author of several chemical treatises in Greek, which have not as *yet been deemed worthy of publicatinn. .See Du Cange, " Gloss, med. etinf.* Gramtatis," voce n«*;Tvs. and Reiiit'su, " Var. I.ectt " L 11. c. a. — H. J52 OF THE HUMAN MIND. have, with the addition of others which they have not ; we may, therefore, form some judgment of their philosophy and ge- ometry, by separating from all others, the perceptions we have by sight and reasoning upon them. As far as I am able to judge in this way, after a careful examination, their geometry must be such as Anepigraphus hath described. Nor does his account of their philosophy appear to contain any evi- dent marks of imposture ; although here, no doubt, proper allowance is to be made for liberties which travellers take, as well as for involuntary mistakes which they are apt to fall into. Section X. OF THE PARALLEL MOTION OF THE EVES. Having explained, as distinctly as we can, visible figure, and shewn its connection with the things signified by it, it will be proper next to consider some phsenomena of the eyes, and of vision, which have com- monly been referred to custom, to anato- mical or to mechanical causes ; but which, as I conceive, must be resolved into origi- nal powers andprinciples of thehumanmind; and, therefore, belong properly to the sub- ject of this inquiry. The first is the parallel motion of the eyes ; by which, when one eye is turned to the right or to the left, upwards or down- wards, or straight forwards, the other always goes along with it in the same direc- tion. We see plainly, when both eyes are open, that they are always turned the same way, as if both were acted upon by the same motive force ; and if one eye is shut, and the hand laid upon it, whi'e the other turns various ways, we feel the eye that is shut turn at the same time, and that whether we will or not. What makes this pheno- menon surprising is, that it is acknowledged, by all anatomists, that the muscles which move the two eyes, and the nerves which serve these muscles, are entirely distinct and unconnected. It would be thought very surprising and unaccountable to see a man, who, from his birth, never moved one arm, without moving the other pre- cisely in the same manner, so as to keep them always parallel— yet it would not be more difficult to find the physical cause of such motion of the arms, than it is to find the cause of the parallel motion of the eyes, which is perfectly similar. The only cause that hath been assigned of this parallel motion of the ejes, is cus- tom. We find by experience, it is said, when we begin to look at objects, that, in order to have distinct vision, it is necessary to turn both eyes the same way j therefore, we soon acquire the habit of doing it con- stantly, and by degrees lose the power of doing otherwise. This account of the matter seems to be insufficient ; because habits are not got at once ; it takes time to acquire and to con- firm them ; and if this motion of the eyes were got by habit, we should see children, when they are born, turn their eyes different ways, and move one without the other, as they do their hands or legs. I know some have affirmed that they are apt to do so. But I have never found it true from my own observation, although I have taken pains to make observations of this kind, and have had good opportunities. I have likewise consulted experienced midwives, mothers, and nurses, and found them agree, that they had never observed distortions of this kind in the eyes of children, but when they had reason to suspect convul- sions, or some preternatural cause. It seems, therefore, to be extremely pro- bable, that, previous to custom, there is something in the constitution, some natural instinct, which directs us to move both eyes always the same way.* We know not how the mind acts upon the body, nor by what power the muscles are contracted and relaxed — but we sec that, in some of the voluntary, as well as in some of the involuntary motions, this power is so directed, that many muscles which have no material tie or connection-f- act in concert, each of them being taught to play its part in exact time and measure. Nor doth a company of expert players in a theatrical performance, or of excellent musicians in a concert, or of good dancers in a country dance, with more regularity and order, conspire and contribute their several parts, to produce one uniform effect, than a number of muscles do, in many of the animal functions, and in many volun- tary actions. Yet we see such actions no less skilfully and regularly performed in children, and in those who know not that they have such muscles, than in the most skilful anatomist and physiologist. Who taught all the muscles that are concerned in sucking, in swallowing our food, in breathing, and in the several na- tural expulsions, to act their part in such regular order and exact measure ? It was not custom surely. It was that same power- ful and wise Being who made the fabric of the human body, and fixed the laws by which the mind operates upon every part • The parallel movemr nt, like other reciprocities of the two eyes, can be explained physiologically, liy the mutual relation of their nerves, without re- curring to any higher or more mysterious principle — t This is not correct. Muscles which have cor. relative motions are now either known or admitted to have correlative ntrves — H. OF SEEING. 153 of it, so that they may answer the pur- poses intended by them. And when we see, in so many other instances, a system of unconnected muscles* conspiring so won- derfully in their several functions, without the aid of habit, it needs not be thought strange, that the muscles of the eyes should, without this aid, conspire to give that di- rection to the eyes, without which they could not answer their end. We see a like conspiring action in the muscles which contract the pupils of the two eyes ; and in those muscles, whatever they be, by which the conformation of the eyes is varied according to the distance of objects It ought, however, to be observed, that, although it appears to be by natural in- stinct that both eyes are always turned the same way, there is still some latitude left for custom. What we have said of the parallel motion of the eyes, is not to be understood so strictly as if nature directed us to keep their axes always precisely and mathematically par- allel to each other. Indeed, although they are always nearly parallel, they hardly ever are exactly so. When we look at an ob- ject, the axes of the eyes meet in that object : and, therefore, make an angle, which is always small, but will be greater or less, according as the object is nearer or more remote. Nature hath very wisely left us the power of varying the parallelism of our eyes a little, so that we can direct them to the same point, whether remote or near. This, no doubt, is learned by custom ; and accordingly we see, that it is a long time before children get this habit in perfection. This power of varying the parallelism of the eyes is naturally no more than is suffi- cient for the purpose intended by it ; but by much practice and straining, it may be increased. Accordingly, we see, that some have acquired the power of distorting their eyes into unnatural directions, as others have acquired the power of distorting their bodies into unnatural postures. Those who have lost the sight of an eye, commonly lose whatthey had got by custom, in the direction of their eyes, but retain what they had by nature ; that is, although their eyes turn and move .always together, yet, when they look upon an object, the blind eye will often have a very small devia- tion from it ; which is not perceived by a slight observer, but may be discerned by one accustomed to make exact observations in these matters. * See the preceding note. Section XI. OF OUR SEEING OBJECTS ERECT BY INVERTED IMAGES. Another phenomenon which hath per- plexed philosophers, is, our seeing objects erect, when it is well known that their images or pictures upon the tunica retina of the eye are inverted. The sagacious Kepler first made the noble discovery, that distinct but inverted pictures of visible objects are formed upon the retina by the rays of light coming from the object. The same great philosopher demonstrated, from the principles of optics, how these pictures are formed — to wit, That the rays coming from any one point of the object, and falling upon the various parts of the pupil, are, by the cornea and crystalline, refracted so as to meet again in one point of the retina, and there paint the colour of that point of the object from which they come. As the rays from dif- ferent points of the object cross each other before they come to the retina, the picture they form must be inverted ; the upper part of the object being painted upon the lower part of the retina., the right side of the object upon the left of the retina, and so of the other parts.* This philosopher thought that we see objects erect by means of these inverted pictures, for this reason, that, as the rays from different points of the object cross each other before they fall upon the retina, we conclude that the impulse which we feel upon the lower part of the retina comes from above, and that the impulse which we feel upon the higher part comes from below. Des Cartes afterwards gave the same solution of this phenomenon, and illustrated it by the judgment which we form of the position of objects which we feel with our arms crossed, or with two-sticks that cross each other. But we cannot acquiesce in this solution. First, Because it supposes our seeing things erect, to be a deduction of reason, drawn from certain premises : whereas it seems to be an immediate perception. And, secondly, Be- cause the premises from which all mankind are supposed to draw this conclusion, never entered into the minds of the far greater part, but are absolutely unknown to them. We have no feeling or perception of the pictures upon the retina, and as little surely * This inverted picture is seen if we take the eye of an ox i for example, and cut away the posterior part of the sclerotica and choroid ; but, without this preparation, it is apparent in the eyes of albino ani- mals, of the owl, &c, in which the hard coat and ctio • aid arc semi-diaphanous. — H. 154 OF THE HUMAN MIND of the position of them. In order to see objects erect, according to the principles of Kepler or Des Cartes, we must previ- ously know that the rays of light come from the object to the eye in straight lines ; we must know that the rays from different points of the object cross one another before they form the pictures upon the retina i and, lastly, we must know that these pictures are really inverted. Now, although all these things are true, and known to philosophers, yet they are absolutely un- known to the far greatest part of mankind : nor is it possible that they who are abso- lutely ignorant of them, should reason from them, and build conclusions upon them. Since, therefore, visible objects appear erect to the ignorant as well as to the learned, this cannot be a conclusion drawn from premises which never entered into the minds of the ignorant. We have indeed had oc- casion to observe many instances of con- clusions drawn, either by means of original principles, or by habit, from premises which pass through the mind very quickly, and which are never made the objects of re- flection ; but surely no man will conceive it possible to draw conclusions fron pre- mises which never entered into the mind at all. Bishop Berkeley having justly rejected this solution, gives one founded upon his own principles ; wherein he is followed by the judicious Dr Smith, in his " Optics;" and this we shall next explain and examine. That ingenious writer conceives the ideas of sight to be altogether unlike those of touch. And, since the notions we have of an object by these different senses have no similitude, we can learn only by experience how one sense will be affected, by what, in a certain manner, affects the other. Figure, position, and even number, in tangible objects, are ideas of touch ; and, although there is no similitude between these and the ideas of sight, yet we learn by expe- rience, that a triangle affects the sight in such a manner, and that a square affects it in such another manner — hence we judge that which affects it in the first manner, to be a triangle, and that which affects it in the second, to be a square. In the same way, finding, from experience, that an object in an erect position affects the eye in one manner, and the same object in an inverted position affects it in another, we learn to judge, by the manner in which the eye is affected, whether the object is erect or in- verted. In a word, visible ideas, according to this author, are signs of the tangible ; and the mind passeth from the sign to the thing signified, not by means of any simi- litude between the one and other, nor by any natural principle, but by having found them constantly conjoined in experience, as the sounds of a language are with the things they signify : so that, if the images upon the retina had been always erect, they would have shewn the objects erect, in the manner as they do now that they are in- verted — nay, if the visible idea which we now have from an inverted object, had been associated from the beginning with the erect position of that object, it would have signi- fied an erect position, as readily as it now signifies an inverted one. And, if the vis- ible appearance of two shillings had been found connected from the beginning with the tangible idea of one shilling, that ap- pearance would as naturally and readily have signified the unity of the object as now it signifies its duplicity. This opinion is, undoubtedly, very inge- nious ; and, if it is just, serves to resolve not only the phsenomenon now under con- sideration, but likewise that which we shall next consider — our seeing objects single with two eyes. It is evident that, in this solution, it is supposed that we do not originally, and previous to acquired habits, see things either erect or inverted, of one figure or another, single or double ; but learn, from experience, to judge of their tangible posi- tion, figure, and number, by certain visible signs. Indeed, it must be acknowledged to be extremely difficult to distinguish the imme- diate and natural objects of sight, from the conclusions which we have been ac- customed from infancy to draw from them. Bishop Berkeley was the first that attempted to distinguish the one from the other, and to trace out the boundary that divides them. And if, in doing so, he hath gone a little to the right hand or to the left, this might be expected in a subject altogether new, and of the greatest subtilty. The nature of vision hath received great light from this distinction ; and many phsenomena in optics, which before appeared altogether unaccountable, have been clearly and dis- tinctly resolved by it. It is natural, and almost unavoidable, to one who hath made an important discovery in philosophy, to carry it a little beyond its sphere, and to apply it to the resolution of phsenomena which do not fall within its province. Even the great Newton, when he had discovered the universal law of gravitation, and ob- served how many of the phaenomena of nature depend upon this, and other laws of attraction and repulsion, could not help ex- pressing his conjecture, that all the phseno- mena of the material world depend upon attracting and repelling forces in the par- ticles of matter. And I suspect that the ingenious Bishop of Cloyne, having found so many phrenomena of vision reducible to the constant association of the ideas of sight OF SEEING. 155 and touch, carried this principle a little be- yond its just limits. In order to judge as well as we can whether it is so, let us suppose such a blind man as Dr Saunderson, having all the knowledge and abilities which a blind man may have, suddenly made to see perfectly. Let us suppose him kept from all opportu- nities of associating his ideas of sight with those of touch, until the former become a little familiar ; and the first surprise, occa- sioned by objects so new, being abated, he has time to canvass them, and to compare them, in his mind, with the notions which he formerly had by touch ; and, in particu- lar, to compare, in his mind, that visible extension which his eyes present, with the extension in length and breadth with which lie was before acquainted. We have endeavoured to prove, that a blind man may form a notion of the visible extension and figure of bodies, from the | i elation which it bears to their tangible I extension and figure. Much more, when this visible extension and figure are presented to his eye, will he be able to compare thein with tangible extension and figure, and to perceive that the one has length and breadth as well as the other ; that the one may be bounded by lines, either straight or curve, as well as the other. And, therefore, he will perceive that there may be visible as well as tangible circles, triangles, quadri- lateral and multilateral figures. And, al- though the visible figure is coloured, and the tangible is not, they may, notwithstand- ing, have the same figure ; as two objects of touch may have the same figure, although one is hot and the other cold. We have demonstrated, that the proper- ties of visible figures differ from those of the plain figures which they represent ; but it was observed, at the same time, that when the object is so small as to be seen distinctly at one view, and is placed directly before the eye, the difference between the visible and the tangible figure is too small to be perceived by the senses. Thus, it is true, that, of every visible triangle, the three angles are greater than two right angles ; whereas, in a plain triangle, the three angles are equal to two right angles ; hut when the visible triangle is small, its three angles will be so nearly equal to two right angles, that the sense cannot discern the difference. In like manner, the circum- ferences of unequal visible circles are not, but those of plain circles are, in the ratio of their diameters ; yet, in small visible circles, the circumferences are very nearly in the ratio of their diameters ; and the diameter bears the same ratio to the circumference, as in a plain circle, very nearly. Hence it appears, that small visible figures (and such only can be seen distinctly at one view) have not only a resemblance to the plain tangible figures which have the name name, but are to all sense the same : so that, if Dr Saunderson had been made to see, and had attentively viewed the figures of the first book of Euclid, he might, by thought and consideration, without touching them, have found out that they were the very figures he was before so well . ac- quainted with by touch. When plain figures are seen obliquely, their visible figure differs more from the tangible ; and the representation which is made to the eye, of solid figures, is still more imperfect ; because visible extension hath not three, but two dimensions only. Yet, as it cannot be said that an exact pic- ture of a man hath no resemblance of the nmn, or that a perspective view of a house hath no resemblance of the house, so it cannot be said, with any propriety, that the visible figure of a man or of a house hath no resemblance of the objects which they represent. Bishop Berkeley therefore proceeds upon a capital mistake, in supposing that there is no resemblance betwixt the extension, figure, and position which we see, and that which we perceive by touch. We may further observe, that Bishop Berkeley's system, with regard to material things, must have made him see this ques- tion, of the erect appearance of objects, in a very different light from that in which it ap- pears to those who do not adopt his system. In his theory of vision, he seems indeed to allow, that there is an external material world : but he believed that this external world is tangible only, and not visible ; and that the visible world, the proper object of sight, is not external, but in the mind. If this is supposed, he that affirms that he eees things erect and not inverted, affirms that there is a top and a bottom, a right and a left in the mind. Now, I confess I am not so well acquainted with the topo- graphy of the mind, as to be able to affix a meaning to these words when applied to it. We shall therefore allow, that, if visible objects were not external, but existed only in the mind, they could have no figure, or position, or extension ; and that it would be absurd to affirm, that they are seen either erect or inverted, or that there is any re- semblance between them and the objects of touch. But when we propose the question, why objects are seen erect and not in- verted, we take it for granted, that we are not in Bishop Berkeley's ideal world, but in that world which men who yield to the dictates of common sense, believe them- selves to inhabit. We take it for granted, that the objects both of sight and touch, arc external, and have a certain figure, and 156 OF THE HUMAN MIND. a certain position with regard to one another, and with regard to our bodies, whether we perceive it or not. When I hold my walking-cane upright in my hand, and look at it, I take it for granted that I see and handle the same individual object. When I say that I feel it erect, my meaning is, that I feel the head directed from the horizon, and the point directed towards it ; and when I say that I see it erect, I mean that I see it with the head directed from the horizon, and the point towards it. I conceive the hori- zon as a fixed object both of sight and touch, with relation to which, objects are said to be high or low, erect or inverted ; and when the question is asked, why I see the ob- ject erect, and not inverted, it is the same as if you should ask, why I see it in that position which it really hath, or why the eye shews the real position of objects, and doth not shew them in an inverted posi- tion, as they are seen by a common astro- nomical telescope, or as their pictures are seen upon the relina of an eye when it is dissected. Section XII. THE SAME SUBJECT CONTINUED. It is impossible to give a satisfactory an- swer to this question, otherwise than by pointing out the laws of nature which take place in vision ; for by these the phseno- mena of vision must be regulated. Therefore, I answer, First, That, by a law of nature, the rays of light proceed from every point of the object to the pupil of the eye, in straight lines ; Secondly, That, by the laws of nature, the rays coming from any one point of the object to the va- rious parts of the pupil, are so refracted as to meet again in one point of the retina ; and the rays from different points of the object, first crossing each other,* and then proceeding to as many different points of the retina, form an inverted picture of the object. So far the principles of optics carry us ; and experience further assures us, that, if there is no such picture upon the retina, there is no vision ; and that such as the picture on the retina is, such is the appear- « It is marvellous how widely both natural philo- sophers and physiologists are at variance with regard *'i the point of the eye at which the rays cross each other. Some place this point in the cornea — some in the region of the pupil— some in the centre of the crystalline — and some in the vitreous humour. Rrccnt experiments, instituted for the purpose of determining its locality, and still unknown in this country, place it tiehind the crystalline lens. This is f- und to be at once the crossing point, both of the rays of light and of the line of visible direction, and the turning point on wlncl' the eye rolls. — H. _ . ance of the object, in colour and figure, distinctness or indistinctness, brightness or faintness. It is evident, therefore, that the pictures upon the retina are, by the laws of nature, a mean of vision ; but in what way they accomplish their end, we are totally igno- rant. Philosophers conceive, that the im- pression made on the retina by the rays of light, is communicated to the optic nerve, and by the optic nerve conveyed to some part of the brain, by them called the senso- rium ; and that the impression thus conveyed to the sensorium is immediately perceived by the mind, which is supposed to reside there. But we know nothing of the seat of the soul : and we are so far from perceiving immediately what is transacted in the brain, that of all parts of the human body we know least about it. It is indeed very probable, that the optic nerve is an instrument of vision no less necessary than the retina ; and that some impression is made upon it, by means of the pictures on the retina. But of what kind this impression is, we know nothing. There is not the least probability that there is any picture or image of the ob- ject either in the optic nerve or brain. The pictures on the retina are formed by the rays of light ; and, whether we suppose, with some, that their impulse upon the re- tina causes some vibration of the fibres of the optic nerve, or, with others, that it gives motion to some subtile fluid contained in the nerve, neither that vibration nor this motion can resemble the visible ob- ject which is presented to the mind. Nor is there any probability that the mind per- ceives the pictures upon the retina. These pictures are no more objects of our percep- tion, than the brain is, or the optic nerve. No man ever saw the pictures in his own eye, nor indeed the pictures in the eye of another, until it was taken out of the head and duly prepared. It is very strange, that philosophers, of all ages, should have agreed in this notion, that the images of external objects are con- veyed by the organs of sense to the brain, and are there perceived by the mind." Nothing can be more unphilosophicaL For, First, This notion hath no foundation in fact and observation. Of all the organs of sense, the eye only, as far as we can disco- ver, forms any kind of image of its object ; and the images formed by the eye are not in the brain, but only in the bottom of the eye ; nor are they at all perceived or felt by the mind.-|- Secondly, It is as difficult • Thi« statement in its unqualified universality is altogether erroneous. — H. t 1 his would renuue a second eye behind the retina; which eye would also see the images bait. OF SEEING. 157 to. conceive how the mind perceives images in the brain, as how it perceives things more distant. If any man will shew how the mind may perceive images in the brain, I will undertake to shew how it may per- ceive the most distant objects ; for, if we give eyes to the mind, to perceive what is transacted at home in its dark chamber, why may we not make these eyes a little longer-sighted ? and then we shall have no occasion for that unphilosophical fiction of images in the brain. In a word, the man- ner and mechanism of the mind's percep- tion is quite beyond our comprehension ; and this way of explaining it, by images in the brain, seems to be founded upon very gross notions of the mind and its opera- tions ; as if the supposed images in the brain, by a kind of contact, formed similar impressions or images of objects upon the mind, of which impressions it is supposed to be conscious. We have endeavoured to shew, through- out the course of this inquiry, that the im- pressions made upon the mind by means of the five senses, have not the least resem- blance to the objects of sense ; and, there- fore, as we see no shadow of evidence that there are any such images in the brain, so we see no purpose, in philosophy, that the supposition of them can answer. Since the picture upon the retina, therefore, is neither itself seen by the mind, nor produces any impression upon the brain or sensorium, which is seen by the mind, nor makes any impression upon the mind that resembles the object, it may still be asked, How this picture upon the retina causes vision ? Before we answer this question, it is pro- per to observe, that, in the operations of the mind, as well as in those of bodies, we must often be satisfied with knowing that cer- tain things are connected, and invariably follow one another, without being able to discover the chain that goes between them. It is to such connections that we give the name of laws of nature ; and when we say that one thing produces another by a law of nature, this signifies no more, but that one thing, which we call in popular lan- guage the cause, is constantly and invari- ably followed by another, which we call the effect ; and that we know not how they are connected. Thus, we see it is a fact, that bodies gravitate towards bodies; and that this gravitation is regulated by certain mathematical proportions, according to the distances of the bodies from each other, and their quantities of matter. Being un- able to discover the cause of this gravita- tion, and presuming that it is the immediate operation, either of the Author of nature, bb they are pictured on the concavity of that mem- brane..— H. or of some subordinate cause, which we have not hitherto been able to reach, we call it a law of nature. If any philoso- pher should hereafter be so happy as to discover the cause of gravitation, this can only be done by discovering some more general law of nature, of which the gravi- tation of bodies is a necessary consequence. In every chain of natural causes, the highest link is a primary law of nature, and the highest link which we can trace, by just induction, is either this primary law of nature, or a necessary consequence of it. To trace out the laws of nature, by induc- tion from the pheenomena of nature, is all that true philosophy aims at, and all that it can ever reach. There are laws of nature by which the operations of the mind are regulated, there are also laws of nature that govern the material system ; and, as the latter are the ultimate conclusions which the human faculties can reach in the philosophy of bodies, so the former are the ultimate con- clusions we can reach in the philosophy of minds. To return, therefore, to the question above proposed, we may see, from what hath been just now observed, that it amounts to this — By what law of nature is a picture upon the retina the mean or occasion of my seeing an external object of the same figure and colour in a contrary position, and in a certain direction from the eye? It will, without doubt, be allowed that I see the whole object in the same manner and by the same law by which I see any one point of it. Now, I know it to be a fact, that, in direct vision, I see every point of the object in the direction of the right line that passeth from the centre of the eye to that point of the object. And I know, likewise, from optics, that the ray of light that comes to the centre of my eye, passes on to the retina in the same direction. Hence, it appears to be a fact, that every point of the otiject is seen in the direction of a right line passing from the picture of that point on the retina, through the centre of the eye. As this is a fact that holds universally and invariably, it must either be a law of nature, or the necessary consequence of some more general law of nature ; and, according to the just rules of philosophising, we may hold it for a law of nature, until some more general law be discovered, whereof it is a necessary conse- quence — which, I suspect, can never be done.* * A confirmation of this doctrine is drawn from the cases of Cheselden and others, in which no men- tal Inversion of the objects is noticed, and which had it occur red, is too remarkable a phenomenon to have been overlooked. It is, indeed, generally asserted ih.i' 158 OF THE HUMAN MIND. Thus, we see that the phenomena of vision lead us by the hand to a law of na- ture, or a law of our constitution, of which law, our seeing objects erect by inverted images, is a necessary consequence. For it necessarily follows, from the law we have mentioned, that the object whose picture is lowest on the retina must be seen in the highest direction from the eye ; and that the object whose picture is on the right of the retina must be seen on the left; so that, if the pictures had been erect in the retina, we should have seen the object in- verted. My chief intention in handling this question, was to point out this law of nature, which, as it is a part of the consti- tution of the human mind, belongs properly to the subject of this inquiry. For this reason, I shall make some farther remarks upon it, after doing justice to the ingenious Dr Porterfield, who, long ago, in the " Medical Essays," or, more lately, in his such inversion has never been observed in any patient, surgically restored to sight. I am aware, however, of one oase of .in opposite purport. It is mentioned, on his own nb-ervation, by a very intelli- gent philosopher and physician, Professor Leiden- fro-it of Duisburg ; and, as his rare worn — " Confes^-io quid putet per Expericntiam didicisse de Mente Humana," I79.J — is altogether unkn >wn in this country, I .•■hall extract from it the whole passage: — " Hae imagines fonnantur in orgnno, non in cerebro. — Mutantur et pcrvcrtuntur ab organo laeso, etiamsi illaesum maneat cerebrum. Non eas con- natas habemus, sed exercitio continuato eas formare discimus. Elegans exemplum habemus in evangelio Marc. H. cf. loll. 9. Vir adultus a nativitate coecus, et potentia miraculosa sancti servatorissubito curatua priino actu visionis uteris distiuguere non poterat, utrumne staturae, quas videtoat, homines eesent, an arbores. Sine dubio jam antcenrationem sciverat ex relatione aliorum,et ex inanuum suarnmexperientia, tdin hominis quam stipitis arboreae staturas < sie erectas, at ulterior! exercitio luerit opus ad utrum- que distinguendum. Aliquid simile aliqnando in juvene propter cataractam congenitam coeco mihi observare licuit. Hie ex paupercula familia rustica ortus, statim post partum utramque pupillam habuit obscuratam; probabiliter membrana pupillaris crassa et opaca erat. I'ro incurabiH habitus nullam cura- tionem habuit. '-anus excrevit, sed plane coecus; omni lumine orbus, in scholas missus lepidi ingenii sigiia dedit. Anno aetitis circiter decimo septimo, nescio ex qua causa gravissima ophthalmia corripitur cum tumure palpebrarum et acerbo dolore. In hoc statu aliqualis medicatio adhibit a est. Observarunt parentes lucera ab eo fugi, a luce rlolores crescere Post aliquot hebdamades febris et ophthalmia de- crescunt; cum summoejus stupore aliqualemluminis usuram nanciscitur. Omit to scribere plures memora- biles hujus visionis conditiones, nam ab eo tempore frequenter, et semper admiraus, eurn conspexi Hoc unum, quod ad rem facit, addo ; imagines in oculo or 1 as penitus ei novas fuisse. Ab initio non paiieba- tur sibi persi iaderi, reliquos homines erectos incedere, putabat hominum capita sui ipsius petlibus esse ob- yersa. Similiter arbores et ohjecta omnia ratione sui inversa esse. Colorum diversitate vehementer delec- tabatur, quorum -mllum conceptual habuerat Nam quamdui coecus erat, si quid de rubro aut alio colore audiverat, id comparaveratcum sensationibus gustus. Kubmm sibi praesentaverat esse aliquid quasi dulce, nigrum cum amarore cy qualities of matter ; dis- tinctions which are thus identified and carried up into a general mw. But of this again H. OF SEEING. Nil four or five inches. We know that, in this case, the raya coining from one point of the object do not meet in one point of the retina, but spread over a small circular spot of it ; the central rays occupying the centre of this circle, the rays that pass above the centre occupying the upper part of the circular spot, and so of the rest. And we know that the object is, in this case, seen confused ; every point of it being seen, not in one, but in various directions. To remedy this confu- sion, we look at the object through the pin- hole, and, while we move the pin-hole over the various parts of the pupil, the object does not keep its place, but seems to move in a contrary direction. It is here to be observed, that, when the pin-hole is carried upwards over the pupil, the picture of the object is carried upwards upon the retina, and the object, at the same time, seems to move downwards, so as to be always in the right line, passing from the picture through the centre of the eye. It is likewise to be observed, that the rays which form the upper and the lower pictures upon the retina do not cross each other, as in or- dinary vision; yet, still, the higher picture shews the object lower, and the lower pic- ture shews Jhe objeet higher, in the same manner as when the rays cross each other. Whence we may observe, by the way, that this phsenomenon of our seeing objects in a position contrary to that of their pictures upon the retina, does not depend upon the crossing of the rays, as Kepler and Des Cartes conceived. Experiment 3. Other things remaining as in the last experiment, make thre^ pin- holes in a straight line, so near that the rays coming from the object through all the holes may enter the pupil at the same time. In this case, we have a very curious phsenome- non ; for the object is seen triple with one eye. And if you make more holes within the breadth of the pupil, you will see as many objects as there are holes. However, we shall suppose them only three — one on the right, one in the middle, and one on the left ; in which case you see three objects standing in a line from right to left. It is here to be observed, that there are three pictures on the retina ; that on the left being formed by the rays which pass on the left df the eye's centre, the middle picture being formed by the central rays, and the right-hand picture by the rays which pass on the right of the eye's centre. It is farther to be observed, that the object which appears on the right, is not that which is seen through the hole on the right, but that which is seen through the hole on the left; and, in like manner, the left- hand object is seen through the hole on the right, as is easily proved by covering the holes successively : so that, whatever is the direction of the rays which form the right-hand and left-hand pictures, still the right-hand picture shews a left-hand object, and the left-hand picture shews a right- hand object. Experiment 4. It is easy to see how the two last experiments may be varied, by placing the object beyond the farthest limit of distinct vision. In order to make this experiment, I looked at a candle at the dis- tance of ten feet, and put the eye of my spectacles behind the card, that the rays from the same point of the object might meet and cross each other, before they reached the retina. In this case, as in the former, the candle was seen triple through the three pin-holes ; but the candle on the right was seen through the hole on the right ; and, on the contrary, the left-hand candle was seen through the hole on the left. In this experiment it is evident, from the principles of optics, that the rays forming the several pictures on the retina cross each other » little before they reach the retina ; and, therefore, the left-hand picture is formed by the rays which pass through the hole on the right : so that the position of the pictures is contrary to that of the holes by which they are formed ; and, therefore, is also contrary to that of their objects — as we have found it to be in the former experiments. These experiments exhibit several un- common phenomena, that regard the appa- rent place, and the direction of visible objects from the eye ; phenomena that seem to be most contrary to the common rules of vision. When we look at the same time through three holes that are in a right line, and at certain distances from each other, we expect that the objects seen through them should really be, and should appear^to be, at a distance from each other. Yet, by the first experiment, we may, through three such holes, see the same object, and the same point of that object ; and through all the three it appears in the same individual place and direction. When the rays of light come from the object in right lines to the eye, without any reflection, inflection, or refraction, we expect that the object should appear in its real and proper direction from --the eye ; and so it commonly does. But in the second, third, and fourth experiments, we see the object in a direction which is not its true and real direction from the eye, although the rays come from the object to the eye, without any inflection, reflection, or refraction. ', When both the object and the eye are fixed without the least motion, and the medium unchanged, we expect that the objeet should appear to rest, and keep the same place. "Yet, in the second and fourth 162 OF THE HUMAN MIND. experiments, when both the eye and the ob- ject are at rest, and the medium unchanged, we make the object appear to move upwards or downwards, or in any direction we please. When we look, at the same time and irith the same eye, through holes that stand in a line from right to left, we expect that the object seen through the left- hand hole should appear on the left, and the object seen through the right-hand hole should appear on the right. Yet, in the third experiment, we find the direct contrary. Although many instances occur in see- ing the same object double with two eyes, we always expect that it should appear single when seen only by one eye. Yet, in the second and fourth experiments, we have instances wherein the same object may appear double, triple, or quadruple to one eye, without the help of a polyhedron or multiplying glass. All these extraordinary phsenomena, re- garding the direction of visible objects from the eye, as well as those that are common and ordinary, lead us to that law of nature which I have mentioned, and are the neces- sary consequences of it. And, as there is no probability that we shall ever be able to give a reason why pictures upon the retina make us see external objects, any more than pictures upon the hand or upon the cheek ; or, that we shall ever be able to give a reason, why we see the object in the direction of a line passing from its picture through the centre of the eye, rather than in any other direction — I am, therefore, apt to look upon this law as a primary law of our constitution. To prevent being misunderstood, I beg the reader to observe, that I do not mean to affirm that the picture upon the retina will make us see an object in the direction mentioned, or in any direction, unless the optic nerve, and the other more immediate instruments of vision, be sound, and per- form their function. We know not well what is the office of the optic nerve, nor in what manner it performs that office ; but that it hath some part in the faculty of see- ing, seems to be certain ; because, in an amaurosis, which is believed to be a disorder of the optic nerve, the pictures on the retina are clear and distinct, and yet there is no vision. We know still less of the use and func- tion of the choroid membrane ; but it seems likewise to be necessary to vision : for it is well known, that pictures upon that part of the retina where it is not covered by the choroid — I mean at the entrance of the optic nerve — produce no vision, any more than a picture upon the hand. • We ac- * TCeid here adopts the theory of Mariotte, who first discovered tno curious fact of this local insensibility. knowledge, therefore, that the retina is not the last and most immediate instrument of the mind in vision. There are other mate- rial organs, whose operation is necessary to seeing, even after the pictures upon the retina are formed. If ever we come to know the structure and use of the choroid membrane, the optic nerve, and the brain, and what impressions are made upon them by means of the pictures on the retina, some more links of the chain may be brought within our view, and a more general law of vision discovered ; but, while we know so little of the nature and office of these more immediate instruments of vision, it seems to be impossible to trace its laws be- yond the pictures upon the retina. Neither do I pretend to say, that there may not be diseases of the eye, or accidents, which may occasion our seeing objects in a direction somewhat different from that men- tioned above. I shall beg leave to mention one instance of this kind that concerns my- self. In May 1761, being occupied in making an exact meridian, in order to observe the transit of Venus, I rashly directed to the sun, by my right eye, the cross hairs of a small telescope. I had often done the like in my younger days with impunity ; but I suffered by it at last, which I mention as a warning to others. I soon observed a remarkable dimness in that eye ; and for many weeks, when I was in the dark, or shut my eyes, there ap- peared before the right eye a lucid spot, which trembled much like the image of the sun seen by reflection from water. This appearance grew fainter, and less frequent, by degrees ; so that now there are seldom any remains of it. But some other very sensible effects of this hurt still remain. For, First, The sight of the right eye con- tinues to be more dim than that of the left. Secondly, The nearest limit of distinct vision is more remote in the right eye than in the other; although, before the time mentioned, they were equal in both these respects, as I had found by many trials. But, thirdly, what I chiefly intended to mention is, That a straight line, in some circumstances, appears to the right eye to have a curvature in it. Thus, when I look upon a music book, and, shutting my left eye, direct the right to a point of the mid- and who ingeniously employed it in support of bit opinion, that the choroid, not the retina, is the proximate organ in vision. But not only is the ab- sence of the choroid not to be viewed as the cause ol this phenomenon : it is not even to be attributed to the entrance of the optic nerve. For it is proved that the impassive portion of the retina does not occupy above a third part of the disc, corresponding o the circumference of that nerve ; and the conjec- '"1? ?f Rudolph, seems probable, that the insensi- bility islirmted to the spot where the arteria centralit enters.— H, OF SEEING. 163 die line of the five which compose the staff of music, the middle line appears dim, in- deed, at the point to which the eye is di- rected, hut straight ; at the same time, the two lines above it, and the two below it, appear to be bent outwards, and to be more distant from each other and from the middle line, than at other parts of the staff, to which the eye is not directed. Fourthly, Although I have repeated this experiment times innumerable, within these sixteen months, I do not find that custom and ex- perience takes away this appearance of cur- vature in straight lines. Lastly, This ap- pearance of curvature is perceptible when I look with the right eye only, but not when I look with both eyes; yet I see better with both eyes together, than even with the left eye alone. I have related this fact minutely as it is, without regard to any hypothesis ; because I think such uncommon facts deserve to be recorded. I shall leave it to others to con- jecture the cause of this appearance. To me it seems most probable, that a small part of the retina towards the centre is shrunk, and that thereby the contiguous parts are drawn nearer to the centre, and to one another, than they were before ; and that objects, whose images fall on these parts, appear at that distance from each other which corresponds, not to the interval of the parts in their present preternatural contraction, but to their interval in their natural and sound, state. Section XIII. OF SEEING OBJECTS SINGLE WITH TWO EVES. Another phsenomenon of vision which deserves attention, is our seeing objects single with two eyes.* There are two pic- * The opinions relative to single vision with two eyes, may, I think,be reduced to two supreme classes. The one attempts to shew that there is no difficulty 10 be solved ; the other attempts to solve the difficulty which is admitted. — Under the former class, there are, as L recollect, three hypotheses. The Jirst sup. poses that we see only with one eye — that man is in reality a Cyclops ; the second supposes that the two impressions are not, in fact, made at the same instant In both eyes, and, consequently, that two simulta- neous impressions are not conveyed to the brain and mind ; the third supposes that, although a separate impression be made on each retina, yet that these several impressions are, as it were, fused into one before they reach the common sensory, in conse. quence of a union of the optic nerves. — The hypo- theses of the latter class which, I think, may also be reduced to three, all admit that there are simultaneous impressions on the two retimB, and that these im- pressions are separately conveyed to the termination of the organic apparatus ; but still hold that, in the mind, there is determined only a single perception. One opinion allows the perception to have been origi- nally twofold, and saves the phenomenon, by suppos- ing that it became single through the influence of cus- tom and association. Another explains it more sub- jectively, by an ultimate and inexplicable law of our tures of the object, one on each retina , and each picture by itself makes us see an object in a certain direction from the eye ; yet both together commonly make us see only one object. All the accounts or solu- tions of this phsenomenon given by anato- mists and philosophers seem to be unsatisfac- tory. I shall pass over the opinions of Galen, of Gassendus, of Baptista Porta, and of Ro- hault. The reader may see these examined and refuted by Dr Porterfield. I shall ex- amine Dr Porterfield's own opinion, Bishop Berkeley's, and some others. But it will be necessary first to ascertain the facts : for, if we mistake the phsenomena of single and double vision, it is ten to one but this mis- take will lead us wrong in assigning the causes. This likewise we ought carefully to attend to, which is acknowledged in theory by all who have any true judgment or just taste in inquiries of this nature, but is very often overlooked in practice — namely, that, in the solution of natural phsenomena, all the length that the human faculties can carry us, is only this, that, from particular phsenomena, we may, by induction, trace out general phsenomena, of which all the particular ones are necessary consequences. And when we have arrived at the most general phsenomena we can reach, there we must stop. If it is asked, Why such a body gravitates towards the earth ? all the answer that can be given is, Because all bodies gravitate towards the earth. This is resolving a particular phsenomenon into a general one. If it should again be asked, Why do all bodies gravitate towards the earth ? we can give no other solution of this phsenomenon, but that all bodies whatso- ever gravitate towards each other. This is resolving a general phsenomenon into a more general one. If it should be asked, Why all bodies gravitate to one another ? we cannot tell ; but, if we could tell, it could only be by resolving this universal gravita- tion of bodies into some other phaenomenon still more general, and of which the gravi- tation of all bodies is a particular instance. The most general phsenomena we can reach, are what we call laws of nature ; so that the laws of nature are nothing else but the most general facts relating to the operations of nature, which include a great many parti- cular facts under them. And if, in any case, we should give the name of a law of nature to a general phsenomenon, which human industry shall afterwards trace to one more general, there is no great harm done. The most general assumes the name of a law of nature when it is discovered, and the less general is contained and comprehended in it. Having premised these things, we pro- ceed to consider the phsenomena of single constitution j and the last, more'objectisely, on some intelligible principle of optics.— H. MS 164 OF THE HUMAN MIND, and double vision, in order to discover some general principle to which they all lead, and of which they are the necessary conse- quences. If we can discover any such general principle, it must either be a law of nature, or the necessary consequence of some law of nature ; and its authority will be equal whether it is the first or the last. 1. We find that, when the eyes are sound and perfect, and the axes of both directed to one point, an object placed in that point is seen single — and here we observe, that in this case the two pictures which shew the object single, are in the centres of the retina. When two pictures of a small object are formed upon points of the retina, if they shew the object single, we shall, for the sake of perspicuity, call such two points of the retina, corresponding points ; and where the object is seen double, we shall call the points of the retina on which the pictures are formed, points that do not cor- respond* Now, in this first phsenomenon, it is evident, that the two centres of the retina are corresponding points. 2. Supposing the same things as in the last phsenomenon, other objects at the same distance from the eyes as that to which their axes are directed, do also appear single. Thus, if I direct my eyes to a candle placed at the distance of ten feet, and, while I look at this caudle, another stands at the same distance from my eyes, within the field of vision, I can, while I look at the first candle, attend to the ap- pearance which the second makes to the eye ; and I find that in this case it always appears single. It is here to be observed, that the pictures of the second candle do not fall upon the centres of the retina, but they both fall upon the same side of the centres — that is, both to the right, or both to the left ; and both are at the same dis- tance from the centres. This might easily be demonstrated from the principles of optics. Hence it appears, that in this second phsenomenon of single vision, the corresponding points are points of the two retinae, which are similarly situate with respect to the two centres, being both upon the same side of the centre, and at the same distance from it. It appears likewise, from this phsenomenon, that every point in one retina corresponds with that which is simi- larly situate in the other. • It is to be noticed that Reid uses the terms, cor. responding points in a sense opposite to that of Smith, ana someoptical writers; thpy use it anatomi. cally, he physiologically. Two points are anatomi. cally correspondent, when on opposite sides of the body they severally hold the same relation to the centre. J. Mueller, and other recent physiologists, employ these terms in the same signification as Reid. An argument a priori has been employed against the doctrine here maintained, on the ground that the congruent points in the opposite eyes are not snatomically corresponding points.— H. 3^ Supposing still the same things, ob. jects which are much nearer to the eyes, or much more distant from them, than that to which the two eyes are directed, appear double. Thus, if the candle is placed at the distance of ten feet, and I hold my finger at arms-length between my eyes and the can- dle — when I look at the candle, I see my fin- ger double ; and when I look at my finger, 1 see the candle double ; and the same thing happens with regard to all other objects at like distances which fall within the sphere of vision. In this phsenomenon, it is evi- dent to those who understand the prin- ciples of optics, that the pictures of the ob- jects which are seen double, do not fall upon points of the retina which are similarly sit- uate, but that the pictures of the objects seen single do fall upon points similarly situate. Whence we infer, that, as the points of the two retina, which are similarly situate with regard to the centres, do correspond, so those which are dissimilarly situate do not correspond. 4. It is to be observed, that, although, in such cases as are mentioned in the last phsenomenon, we have been accustomed from infancy to see objects double which we know to be single ; yet custom, and ex- perience of the unity of the object, never take away this appearance of duplicity. 5. It may, however, be remarked that the custom of attending to visible appear- ances has a considerable effect, and makes the phsenomenon of double vision to be more or less observed and remembered. Thus you may find a man that can say, with a good conscience, that he never saw things double all his life ; yet this very man, put in the situation above mentioned, with his finger between him and the candle, and de- sired to attend to the appearance of the object which he does not look at, will, upon the first trial, see the candle double, when he looks at his finger ; and his finger double, when he looks at the candle. Does he now see otherwise than he saw before ? No, surely; but he now attends to what he never attended to before. The same double appearance of an object hath been a thou- sand times presented to his eye before now, but he did not attend to it ; and so it is as little an object of his reflection and memory, as if it had never happened. When we look at an object, the circum- jacent objects may be seen at the same time, although more obscurely and indis- tinctly: for the eye hath a considerable field of vision, which it takes in at once. But we attend only to the object we look at. The other objects which fall within the field of vision, are not attended to ; and therefore are as if they were not seen. If any of them draws our attention, it naturally draws the eyes at the same time : for, in the com- OE SEEING. 165 mon course of life, the eyes always follow the attention : or if at any time, in a revery, they are separated from it, we hardly at that time see what is directly before us. Hence we may see the reason why the man we are speaking of thinks that he never before saw an object double. When he looks at any object, he sees it single, and takes no notice of other visible objects at that time, whether they appear single or double. If any of them draws his attention, it draws his eyes at the same time ; and, as soon as the eyes are turned towards it, it appears single. But, in order to see things double — at least, in order to have any reflec- tion or remembrance that he did so — it is necessary that he should look at one object, and at the same time attend to the faint appearance of other objects which are within the field of vision. This is a practice which perhaps he never used, nor attempted ; and therefore he does not recollect that ever he saw an object double. But when he is put upon giving this attention, he immediately sees objects double, in the same manner, and with the very same circumstances, as they who have been accustomed, for the greatest part of their lives, to give this attention. There are many phsenomena of a similar nature, which shew that the mind may not attend to, and thereby, in some sort, not perceive objects that strike the senses. I had occasion to mention several instances of this in the second chapter ; and I have been assured, by persons of the best skill in music, that, in hearing a tune upon the harpsichord, when they give attention to the treble, they do not hear the bass ; and when they attend to the bass, they do not perceive the air of the treble. Some per- sons are so near-sighted, that, in reading, they hold the book to one eye, while the other is directed to other objects. Such persons acquire the habit of attending, in this case, to the objects of one eye, while they give no attention to those of the other. 6. It is observable, that, in all cases wherein we see an object double, the two appearances have a certain position with regard to one another, and a certain appar- ent or angular distance. This apparent distance is greater or less in different cir- cumstances ; but, in the same circumstances, it is always the same, not only to the same, but to different persons. Thus, in the experiment above mentioned, if twenty different persons, who see perfectly with both eyes, shall place their finger and the candle at the distances above expressed, and hold their heads upright, looking at the finger, they will see two candles, one on the right, another on the left. That which is seen on the right, is seen by the right eye, and that which is seen on the left, by the left eye ; and they will see them at the same apparent distance from each other. If, again, they look at the candle, they will see two fingers, one on the right, and the other on the left ; and all will see them at the same apparent distance ; the finger towards the left being seen by the right eye, and the other by the left. If the head is laid horizontally to one side, other circum- stances remaining the same, one appearance of the object seen double, will be directly above the other. In a word, vary the cir- cumstances as you please, and the appear- ances are varied to all the spectators in one and the same manner. 7. Having made many experiments in order to ascertain the apparent distance of the two appearances of an object seen double, I have found that in all cases this apparent distance is proportioned to the distance be- tween the point of the retina, where the picture is made in one eye, and the point which is situated similarly to that on which the picture is made on the other eye ; so that, as the apparent distance of two objects seen with one eye, is proportioned to the arch of the retina, which lies between their pictures, in like manner, when an object is seen double with the two eyes, the apparent distance of the two appearances is propor- tioned to the arch of either retina, which lies between the picture in that retina, and the point corresponding to that of the pic- ture in the other retina. 8. As, in certain circumstances, we in- variably see one object appear double, so, in others, we as invariably see two objects unite into one, and, in appearance, lose their duplicity. This is evident in the ap- pearance of the binocular telescope. And the same thing happens when any two simi- lar tubes are applied to the two eyes in a, parallel direction ; for, in this case, we see only one tube. And if two shillings are placed at the extremities of the two tubes, one exactly in the axis of one eye, and the other in the axis of the other eye, we shall see but one shilling. If two pieces of coin, or other bodies, of different colour, and of different figure, be properly placed in the two axes of the eyes, and at the extremi- ties of the tubes, we shall see both the bodies in one and the same place, each' as it were spread over the other, withouthid- ing it j and the colour will be that which is compounded of the two colours.* * Thia last statement is incorrect; it misrepresents* if it does not reverse, the observation of Du Tour- But, though Reid's assertion be inaccurate, there is great difference (probably from the different consti. tution ot their organs) in the phattiomeno-, as re- ported by various observers. None, seemingly, (the reverse of what Reid says,) in looking, e. g., with one eye through a blue, and with the other through a yellow glass, experience a comple- mentary sensation of green. But some see both colours at once; some only one colour— a colour, however, which corresponds neither to yellow nor tc blue, and, at the same time, is not gieen. Jn rr.y 1( OF THE HUMAN MIND. 9. From these pheenomena, and from all the trials I have been able to make, it ap- pears evidently, that, in perfect human eyes, the centres of the two retina correspond and harmonize wth one another, and that every other point in one retina doth correspond and harmonize with the point which is similarly situate in the other ; in such man- ner, that pictures falling on the corre- sponding points of the two retina, shew only one object, even when there are really two ; and pictures falling upon points of the retina which do not correspond, shew us two visible appearances, although there be but one object : so that pictures, upon corresponding points of the two retinas, pre- sent the same appearance to the mind as if they had both fallen upon the same point of one retina ; and pictures upon points of the two retina, which do not correspond, present to the mind the same apparent distance and position of two objects, as if one of those pictures was carried to the point corresponding to it in the other retina. This relation and sympathy between cor- responding points of the two retina, I do not advance as an hypothesis, but as a general fact or phcenomenon of vision. All the pheenomena before mentioned, of single or double vision, lead to it, and are neces- sary consequences of it. It holds true in- variably in all perfect human eyes, as far as I am able to collect from innumerable trials of various kinds made upon my own eyes, and many made by others at my de- sire. Most of the hypotheses that have been contrived to resolve the pheenomena of single and double vision, suppose this general fact, while their authors were not aware of it. Sir Isaac Newton, who was too judicious a philosopher, and too accu- rate an observer, to have offered even a conjecture which did not tally with the facts that had fallen under his observation, pro- poses a query with respect to the cause of it — " Optics," Query, 15. The judicious Dr Smith, in his " Optics," Book 1, § 137, hath confirmed the truth of this general phenomenon from his own experience, not only as to the apparent unity of objects whose pictures fall upon the corresponding points of the retina, but also as to the ap- parent distance of the two appearances of the same object when seen double.* own eye, I can see either of these phenomena, under certain conditions, at will. Johannes Mueller, Weber, Volkmann, and Heermann, are the most recent observers. 1 may also notice, that the congruence between the corresponding points (in Reid's sense) of the two retinje, is admitted for the perception of figure, but not for the sensations of tight and colour. — H, » It might be proper here to say something of the strictures of Dr Wells on Reid's doctrine of single vision ; but, as the matter is, after all, of no high psychological. importance, while the whole theory of the form of the Horopter is, in consequence of Mueller's observations, anew under discussion, I shall This general phsenomenon appears, there- fore, to be founded upon a very full induc- tion, which is all the evidence we can have for a fact of this nature. Before we make an end of this subject, it will be proper to inquire, First, Whether those animals whose eyes have an adverse position in their heads, and look contrary ways, have such corre- sponding points in their retinae? Secondly, What is the position of the corresponding points in imperfect human eyes — I mean in those that squint ? And, in the last place, Whether this harmony of the correspond- ing points in the retinae, be natural and original, or the effect of custom ? And, if it is original, Whether it can be accounted for by any of the laws of nature already discovered ? or whether it is itself to be looked upon as a law of nature, and a part of the human constitution ? Section XIV. OF THE LAWS OF VISION IN BRUTE ANIMALS. It is the intention of nature,in giving eyes to animals, that they may perceive the situation of visible objects, or the direction in which they are placed — it is probable, therefore, that, in ordinary cases, every animal, whether it has many eyes or few, whether of one structure or of another, sees objects single, and in their true and proper direction. And, since there is a prodigious variety in the structure, the motions, and the number of eyes in different animals and insects, it is probable that the laws by which vision is regulated, are not the same in all, but various, adapted to the eyes which nature hath given them. Mankind naturally turn their eyes al- ways the same way, so that the axes of the two eyes meet in one point. They natur- ally attend to, or look at that object only which is placed in the point where the axes meet. And whether the object be more or less distant, the configuration of the eye is adapted to the distance of the object, so as to form a distinct picture of it. When we use our eyes in this natural way, the two pictures of the object we look at are formed upon the centres of the two retinae ; and the two pictures of any con- tiguous object are formed upon the points of the retina which are similarly situate with regard to the centres. Therefore, in order to our seeing objects single, and in their proper direction, with two eyes, it is only refer the jeader who is curious in such points, to the following recent publications :— J. Mueller, '* Zur Vergleichenden Physiologie de- Gesichtssin. nes," &c., 1826.— Volkmann, "Neue Beytraege Bur Physiologie des Gesich'tssinnes," 183fi.— Heermann, " Ueber dieBildungder Gesichtsvorstellungcn,"&c a OP SEEING. 167 sufficient that we be so constituted, that objects whose pictures are formed upon the centres of the two retina, or upon points similarly situate with regard to these centres, shall be seen in the same visi- ble place. And this is the constitution which nature hath actually given to human eyes. When we distort our eyes from their parallel direction, which is an unnatural motion, but may be learned by practice ; or when we direct the axes of the two eyes to one point, and at the same time direct our attention to some visible object much nearer or much more distant than that point, which is also unnatural, yet may be learned : in these cases, and in these only, we see one object double, or two objects confounded in one. In these cases, the two pictures of the same object are formed upon points of the retina which are not similarly situate, and so the object is seen double ; or the two pictures of different objects are formed upon points of the retina which are simi- larly situate, and so the two objects are seen confounded in one place. Thus it appears, that the laws of vision in the human constitution are wisely adapted to the natural use of human eyes, but not to that use of them which is uunatural. We see objects truly when we use our eyes in the natural way ; but have false appearances presented to us when we use them in a way that is unnatural. We may reasonably think that the case is the same with other animals. But is it not unreasonable to think, that those animals which naturally turn one eye towards one obj ect, and another eye towards another object, must thereby have such false appearances presented to them, as we have when we do so against nature ? Many animals have their eyes by nature placed adverse and immoveable, the axes of the two eyes being always directed to opposite points. Do objects painted on the centres of the two retinae appear to such animals as they do to human eyes, in one and the same visible place ? I think it is highly probable that they do not ; and that they appear, as they really are, in opposite places. If we judge from analogy in this case, it will lead us to think that there is a certain correspondence between points of the two retinas in such animals, but of a different kind from that which we have found in human eyes. The centre of one retina will correspond with the centre of the other, in such manner that the objects whose pictures are formed upon these correspond- ing points, shall appear not to be in the same place, as in human eyes, but in op- posite places. And in the same manner will the superior part of one retina corre- spond with the inferior part of the other, and the anterior part of one with the pos- terior part of the other. Some animals, by nature, turn their eyes with equal facility, either the same way or different ways, as we turn oiir hands and arms. Have such animals corresponding points in their retina, and points which do not correspond, as the human kind has ? I think it is probable that they have not ; because such a constitution in them could serve no other purpose but to exhibit false appearances. If we judgefrom analogy, it will lead us to think, that, as such animals move their eyes in a manner similar to that in which we move our arms, they have an immediate and natural perception of the direction they give to their eyes, as we have of the direc- tion we give to our arms ; and perceive the situation of visible objects by their eyes, in a manner similar to that in which we per- ceive the situation of tangible objects with our hands. We cannot teach brute animals to use their eyes in any other way than in that which nature hath taught them ; nor can we teach them to communicate to us the appearances which visible objects make to them, either in ordinary or in extraordinary cases. We have not, therefore, the same means of discovering the laws of vision in them, as in our own kind, but must satisfy ourselves with probable conjectures ; and what we have said upon this subject, is chiefly intended to shew, that animals to which nature hath given eyes differing in their number, in their position, and in their natural motions, may very probably be subjected to different laws of vision, adapted to the peculiarities of their organs of vision. Section XV. SQUINTING CONSIDERED HYPOTHETICALLY. Whether there be corresponding points in the retinae of those who have an invo- luntary squint ? and, if there are, Whether they be situate in the same manner as in those who have no squint ? are not ques- tions of mere curiosity. They are of real importance to the physician who attempts the cure of a squint, and to the patient who submits to the cure. After so much has been said of the strabismus, or squint, both by medical and by optical writers, one might expect to find abundance of facts for deter- mining these questions. Yet, I confess, I have been disappointed in this expectation, after taking some pains both to make ob- servations, and to collect those which have been made by others. 168 OF THE HUMAN MIND. Nor will this appear very strange, if we eonsider, that to make the observations which are necessary for determining these questions, knowledge of the principles of optics, and of the laws of vision, must concur with opportunities rarely to be met with. Of those who squint, the far greater part have no distinct vision with one eye. * When this is the case, it is impossible, and indeed of no importance, to determine the situation of the corresponding points. When both eyes are good, they commonly differ so much in their direction, that the same object cannot be seen by both at the same time ; and, in this case, it will be very difficult to determine the situation of the corresponding points ; for such per- sons will probably attend only to the ob- jects of one eye, and the objects of the other will be as little regarded as if they were not seen. We have before observed, that, when we look at a near object, and attend to it, we do not perceive the double appearances of more distant objects, even when they are in the same direction, and are presented to the eye at the same time. It is probable that a squinting person, when he attends to the objects of one eye, will, in like manner, have his attention totally diverted from the objects of the other ; and that he will per- ceive them as little as we perceive the double appearances of objects when we use our eyes in the natural way. Such a per- son, therefore, unless he is so much a phi- losopher as to have acquired the habit of attending very accurately to the visible ap- pearances of objects, and even of objects which he does not look at, will not be able to give any light to the questions now under consideration. It is very probable that hares, rabbits, birds, and fishes, whose eyes are fixed in an adverse position, have the natural fa- culty of attending at the same time to vi- sible objects placed in different, and even in contrary directions ; because, without this faculty, they could not have those ad- vantages from the contrary direction of their eyes, which nature seems to have in- tended. But it is not probable that those who squint have any such natural faculty ; because we find no such faculty in the rest of the species. We naturally attend to ob- jects placed in the point where the axes of the two eyes meet, and to them only. To give attention to an object in a different di- rection is unnatural, and not to be learned without pains and practice. * On this imperfection of vision ii rested the theory of Squinting, proposed by Buflbn, and now generally adopted. The defective eye is turned aside, because, if it were directed to the object, together with the perfect one, a confused impression would be produced, — H. A very convincing proof of this may be drawn from a fact now well known to phi- losophers : when one eye is shut, there is a certain space within the field of vision, where we can see nothing at all — the space which is directly opposed to that part of the bottom of the eye where the optic nerve enters. This defect of sight, in one part of the eye, is common to all human eyes, and hath been so from the beginning of the world ; yet it was never known, until the sagacity of the Abb6 Mariotte discovered it in the last century. And now when it is known, it cannot be perceived, but by means of some particular experiments, which re- quire care and attention to make them succeed. What is the reason that so remarkable a defect of sight, common to all mankind, was so long unknown, and is now perceived with so much difficulty ? It is surely this That the defect is at some distance from the axis of the eye, and consequently in a part of the field of vision to which we never attend naturally, and to which we cannot attend at all, without the aid of some par- ticular circumstances. From what we have said, it appears, that, to determine the situation of the cor- responding points in the eyes of those who squint, is impossible, if they do not see dis- tinctly with both eyes ; and that it will be very difficult, unless the two eyes differ so little in their direction, that the same object may be seen with both at the same time. Such patients I apprehend are rare ; at least there are very few of them with whom I have had the fortune to meet : and there- fore, for the assistance of those who may have happier opportunities, and inclination to make the proper use of them, we shall con- sider the case of squinting, hypothetically, pointing out the proper articles of inquiry, the observations that are wanted, and the conclusions that may be drawn from them. 1. It ought to be inquired, Whether the squinting person sees equally well with both eyes ? and, if there be a defect in one, the nature and degree of that defect ought to be remarked. The experiments by which this may be done, are so obvious, that I need not mention them. But I would ad- vise the observer to make the proper ex- periments, and not to rely upon the testi- mony of the patient ; because I have found many instances, both of persons that squint- ed, and others who were found, upon trial, to have a great defect in the sight of one eye, although they were never aware of it before. In all the following articles, it is supposed that the patient sees with both eyes so well as to be able to read with either, when the other is covered. 2. It ought to be inquired, Whether, when one eye is covered, the other is turned OF SEEING. 169 directly to the object ? This ought to be tried in both eyes successively. By this observation, as a touchstone, we may try the hypothesis concerning squinting, in- vented by M. de la Hire, and adopted by Boerhaave, and many others of the medical faculty. The hypothesis is, That, in one eye of- a squinting person, the greatest sensibility and the most distinct vision is not, as in other men, in the centre of the retina, but upon one side of the centre ; and that he turns the axis of this eye aside from the object, in order that the picture of the object may fall upon the most sensible part of the retina, and thereby give the most distinct vision. If this is the cause of squinting, the "(minting eye will be turned aside from the joject, when the other eye is covered, as well as when it is not. A trial so easy to be made, never was made for more than forty years ; but the hypothesis was very generally received — so prone are men to invent hypotheses, and so backward to examine them by facts. At last, Dr Jurin having made the trial, found that persons Iwho squint turn the axis of the squinting eye directly to the obj ect, when the other eye is covered. This fact is confirmed by Dr Porterfield ; and I have found it verified in all the instances that have fallen under my observation. 3. It ought to be inquired, Whether the axes of the two eyes follow one another, so as to have always the same inclination, or make the same angle, when the person looks to the right or to the left, upward or downward, or straight forward. By this observation we may judge whether a squint is owing to any defect in the muscles which move the eye, as some have supposed. In the following articles, we suppose that the inclination of the axes of the eyes is found to be always the same. 4. It ought to be inquired, Whether the person that squints sees an object single or double ? If he sees the object double, and if the two appearances have an angular distance, equal to the angle which the axes of his eyes make with each other, it may be con- cluded that he hath corresponding points in the retina of his eyes, and that they have the same situation as in those who have no squint. If the two appearances should have an angular distance which is always the same, but manifestly greater or less than the angle contained under the optic axes, this would indicate corresponding points in the retina, whose situation is not the same as in those who have no squint ; but it is difficult to judge accurately of the angle which the optic axes make. A squint.too small to be perceived, may occasion double vision of objects : for. if we speak strictly, every person squints more or less, whose optic axes do not meet ex- actly in the object which he looks at. . Thus, if a man can only bring the axes of his eyes to be parallel, but cannot make them converge in the least, he must have a small squint in looking at near objects, and will see them double, while he sees very distant objects single. Again, if the optic axes always converge, so as to meet eight or ten feet before the face at farthest, such a per- son will see near objects single ; but when he looks at very distant objects, he will squint a little, and see them double. An instance of this kind is related by Aguilonius in his " Optics," who says, that he had seen a young man to whom near objects appeared single, but distant objects appeared double. Dr Bi-iggs, in his " Nova Visionis Theo- ria," having collected from authors several instances of double vision, quotes this from Aguilonius, as the most wonderful and un- accountable of all, insomuch that he sus- pects some imposition on the part of the young man : but to those who understand the laws by which single and double vision are regulated, it appears to be the natural effect of a very small squint.* Double vision may always be owing to a small squint, when the two appearances are seen at a small angular distance, although no squint was observed : and I do not . remember any instances of double vision recorded by authors, wherein any account is given of the angular distance of the appearances. In almost all the instances of double vision, there is reason to suspect a squint or distortion of the eyes, from the concomi- tant circumstances, which we find to be one or other of the following — the approach of death or of a deliquium, excessive drink- ing or other intemperance, violent headache, blistering the head, smoking tobacco, blows or wounds in the head. In all these cases, it is reasonable to suspect a distortion of the eyes, either from spasm, or paralysis in the muscles that move them. But, although it be probable that there is always a squint greater or less where there is double vision, yet it is certain that there is not double vision always where there is a squint. I know no instance of double vision that con- tinued for life, or even for a great number of years. We shall therefore suppose, in the following articles, that the squinting person sees objects single. 5. The next inquiry, then, ought to be, Whether the object is seen with both eyes at the same time, or only with the eye « It is observed by Purkinje and Volkmann, that short-sighted persons, under certain conditions, see distant objects double. Is the case of Aguilonius more than an example of this ?— H. 170 OF THE HUMAN MIND. whose axis is directed to it ? It hath been taken for granted, by the writers upon the strabismus, before Dr Jurin, that those who squint commonly see objects single with both eyes at the same time ; but I know not one fact advanced by any writer which proves it. Dr Jurin is of a contrary opi- nion ; and, as it is of consequence, so it is very easy, to determine this point, in parti- cular instances, by this obvious experiment. While the person that squints looks steadily at an object, let the observer carefully re- mark the direction of both his eyes, and observe their motions ; and let an opaque body be interposed between the object and the two eyes successively. If the patient, notwithstanding this interposition, and with- out changing the direction of his eyes, con- tinues to see the object all the time, it may be concluded that he saw it with both eyes at once. But, if the interposition of the body between one eye and the object makes it disappear, then we may be certain that it was seen by that eye only. In the two following articles, we shall suppose the first to happen, according to the common hypo- thesis. 6. Upon this supposition, it ought to be inquired, Whether the patient sees an ob- ject double in those circumstances wherein it appears double to them who have no squint ? Let him, for instance, place a candle at the distance of ten feet; and holding his finger at arm's-length between him and the candle, let him observe, when he looks at the candle, whether he sees his finger with both eyes, and whether he sees it single or double ; and when he looks at his finger, let him observe whether he sees the candle with both eyes, and whether single or double. By this observation, it may be deter- mined, whether to this patient, the phseno- mena of double as well as of single vision are the same as to them who have no squint. If they are not the same — if he sees objects single with two eyes, not only in the cases wherein they appear single, but in those also wherein they appear double to other men — the conclusion to be drawn from this supposition is, that his single vision does not arise from corresponding points in the re- tina of his eyes ; and that the laws of vision are not the same in him as in the rest of mankind. 7. If, on the other hand, he sees objects double in those cases wherein they appear double to others, the conclusion must be, that he hath corresponding points in the retina of his eyes, but unnaturally situate. And their situation may be thus determined. When he looks at an object, having the axis of one eye directed to it, and the axis of the other turned aside from it, let us suppose a right line to pass from the object through the centre of the diverging eye. We shall, for the sake of perspicuity, call this right line, the natural axis of the eye; and it will make an angle with the real axis, greater or less, according as his squint is greater or less. We shall also call that point of the retina in which the natural axis cuts it, the natural centre of the retina ; which will be more or less distant from the real centre, according "as the squint is greater or less. Having premised these definitions, it will be evident to those who understand the principles of optics, that in this person the natural centre of one retina corresponds with the real centre of the other, in the very same manner as the two real centres correspond in perfect eyes ; and that the points similarly situate with regard to the real centre in one retina, and the natural centre in the other, do likewise correspond, in the very same manner as the points si- milarly situate with regard to the two reiJi centres correspond in perfect eyes. If it is true, as has been commonly af- firmed, that one who squints sees an object with both eyes at the same time, and yet sees it single, the squint will most probably be such as we have described in this article. And we may further conclude, that, if a person affected with such a squint as we have supposed, could be brought to the habit of looking straight, his sight would thereby be greatly hurt; for he would then see everything double which he saw with both eyes at the same time ; and ob- jects distant from one another would appear to be confounded together. His eyes are made for squinting, as much as those of other men are made for looking straight ; and his sight would be no less injured by looking straight, than that of another man by squinting. He can never see perfectly when he does not squint, unless the corre- sponding points of his eyes should by custom change their place ; but how small the pro- bability of this is will appear in the 17th section. Those of the medical faculty who attempt the cure of a squint, would do well to con- sider whether it is attended with such symp- toms as are above described. If it is, the cure would be worse than the malady: for, every one will readily acknowledge that it is better to put up with the deformity of a squint, than to purchase the cure by the loss of perfect and distinct vision. 8. We shall now return to Dr Jurin's hypothesis, and suppose that our patient, when he saw objects single notwithstanding his squint, was found, upon trial, to have seen them only with one eye. We would advise such a patient to en- deavour, by repeated efforts, to lessen his squint, and to bring the axes of his eyes OP SEEING. 171 nearer to a parallel direction. We have naturally the power of making small varia- tions in the inclination of the optic axes ; and this power maybe greatly increased by exercise. In the ordinary and natural use of our eyes, we can direct their axes to a fixed star ; in this ease they must be parallel : we can direct them also to an object six inches distant from the eye; and in this case the axes must make an angle of fif- teen or twenty degrees. We see young people in their frolics learn to squint, mak- ing their eyes either converge or diverge, when they will, to a very considerable de- gree. Why should it be more difficult for a squinting person to learn to look straight when he pleases ? If once, by an effort of his will, he can but lessen his squint, fre- quent practice will make it easy to lessen it, and will daily increase his power. So that, if he begins this practice in youth, and perseveres in it, he may probably, after «ome time, learn to direct both his eyes to one object. When he hath acquired this power, it will be no difficult matter to determine, by proper observations, whether the centres of the retina, and other points similarly situate with regard to the centres, correspond, as in other men. 9. Let us now suppose that he finds this to be the case ; and that he sees an object single with both eyes, when the axes of both are directed to it. It will then concern him to acquire the habit of looking straight, as he hath got the power, because he will thereby not only remove a deformity, but improve his sight ; and I conceive this ha- bit, like all others, may be got by frequent exercise. He may practise before a mirror when alone, and in company he ought to have those about him who will observe and ad- monish him when he squints. 10. What is supposed in the 9th article is not merely imaginary ; it is really the case of some squinting persons, as will appear in the next section. Therefore, it ought further to be inquired, How it comes to pass that such a person sees an object which he looks at, only with one eye, when both are open ? In order to answer this question, it may be observed, first, Whether, when he looks at an object, the diverging eye is not drawn so close to the nose, that it can have no distinct images ? Or, secondly, whether the pupil of the diverging eye is not covered wholly, or in part, by the upper eye- lid ? Dr Jurin observed instances of these cases in persons that squinted, and assigns them as causes of their seeing the object only with one eye. Thirdly, it may be observed, whether the diverging eye is not so directed, that the picture of the object falls upon that part of the retina where the optic nerve enters, and where there is no vision ? This will probably happen in a squint wherein the axes of the eyes converge so as to meet about six inches before the nose. 11. In the last place, it ought to be inquired, Whether such a person hath any distinct vision at all with the diverging eye, at the time he is looking at an object with the other ? It may seem very improbable that he should be able to read with the diverging eye when the other is covered, and yet, when both are open, have no distinct vision with it at all. But this, perhaps, will not appear so improbable if the following considerations are duly attended to. Let us suppose that one who saw per- fectly, gets, by a blow on the head, or some other accident, a permanent and involun- tary squint. According to the laws of vi- sion, he will see objects double, and will see objects distant from one another confounded together ; but, such vision being very dis- agreeable, as well as inconvenient, he will do everything in his power to remedy it. For alleviating such distresses, nature often teaches men wonderful expedients, which the sagacity of a philosopher would be un- able to discover. Every accidental motion, every direction or conformation of his eyes, which lessens the evil, will be agreeable ; it will be repeated until it be learned to perfection, and become habitual, even with- out thought or design. Now, in this case, what disturbs the sight of one eye is the sight of the other ; and all the disagreeable appearances in vision would cease if the light of one eye was extinct. The sight of one eye will become more distinct and more agreeable, in the same proportion as that of the other becomes faint and in- distinct. It may, therefore, be expected, that every habit will, by degrees, be ac- quired which tends to destroy distinct vi- sion in one eye while it is preserved in the other. These habits will be greatly facili- tated if one eye was at first better than the other ; for, in that case, the best eye will always be directed to the object which he intends to look at, and every habit will be acquired which tends to hinder his seeing it at all, or seeing it distinctly by the other at the same time. I shall mention one or two habits that may probably be acquired in such a, case ; perhaps there are others which we cannot so easily conjecture. First, By a small in- crease or diminution of his squint, he may bring it to correspond with one or other of the cases mentioned in the last article. Secondly, The diverging eye may be brought to such a conformation as to be extremely short-sighted, and consequently to have no distinct vision of objects at a distance. I 172 OF THE HtlMAN MINI). knew this to be the case of one person that squinted ; but cannot say whether the short-sightedness of the diverging eye was original, or acquired by habit. We see, therefore, that one who squints, and originally saw objects double by reason of that squint, may acquire such habits that, when he looks at an object, he shall see it only with one eye ; nay, he may ac- quire such habits that, when he looks at an object with his best eye, he shall have no distinct vision with the other at all. Whether this is really the case — being unable to de- termine in the instances that have fallen under my observation — I shall leave to fu- ture inquiry. I have endeavoured, in the foregoing articles, to delineate such a process as is proper in observing the phsenomena of squinting. I know well by experience, that this process appears more easy in theory, than it will be found to be in practice ; and that, in order to carry it on with success, some qualifications of mind are necessary in the patient, which are not always to be met with. But, if those who have proper opportunities and inclination to observe such phsenomena, attend duly to this pro- cess, they may be able to furnish facts less vague and uninstructive than those we meet with, even in authors of reputation. By such facts, vain theories may be exploded, and our knowledge of the laws of nature, which regard the noblest of our senses, enlarged. Section XVI. FACTS RELATING TO SQUINTING. Having considered the phsenomena of squinting, hypothetically, and their connec- tion with corresponding points in the re- tincB, I shall now mention the facts I have had occasion to observe myself, or have met with in authors, that can give any light to this subject. Having examined above twenty persons that squinted, I found in all of them a de- fect in the sight of one eye. Four only had so much of distinct vision in the weak eye, as to be able to read with it, when the other was covered. The rest saw nothing at all distinctly with one eye. Dr Porterfield says, that this is generally the case of people that squint : and I sus- pect it is so more generally than is com- monly imagined. Dr Jurin, in a very judicious dissertation upon squinting, printed in Dr Smith's " Optics," observes, that those who squint, and see with both eyes, never see the same object with both at the same time ; that, when one eye is directs' strni'^'.t forward to an object, the other is drawn so close to the nose that the object cannot at all be seen by it, the images being too oblique and too indistinct to affect the eye. In some squinting per- sons, he observed the diverging eye drawn under the upper eyelid, while the other was directed to the object. From these observations, he concludes that " the eye is thus distorted, not for the sake of seeing better with it, but rather to avoid seeing at all with it as much as possible." From all the observations he had made, he was satis- fied that there is nothing peculiar in the structure of a squinting eye ; that the fault is only in its wrong direction; and that this wrong direction is got by habit. There- fore, he proposes that method of cure which we have described in the eighth and ninth articles of the last section. He tells ns, that he had attempted a cure, after this method, upon a young gentleman, with promising hopes of success ; but was in- terrupted by his falling ill of the small- pox, of which he died. It were to be wished that Dr Jurin had acquainted us whether he ever brought the young man to direct the axes of both eyes to the same object, and whether, in that case, he saw the object single, and saw it with both eyes ; and that he had likewise acquainted ns, whether he saw objects double when his squint was diminished. But as to these facts he is silent. I wished long for an opportunity of trying Dr Jurin's method of curing a squint, with- out finding one ; having always, upon ex- amination, discovered so great a defect in the sight of one eye of the patient as dis- couraged the attempt. But I have lately found three young gentlemen, with whom I am hopeful this method may have success, if they have patience and perseverance in using it. Two of them are brothers, and, before I had access to examine them, had been practis- ing this method by the direction of their tutor, with such success that the elder looks straight when he is upon his guard : the younger can direct both his eyes to one object ; but they soon return to their usual squint. A third young gentleman, who had never heard of this method before, by a few days practice, was able to direct both his eyes to one object, but could not keep them long in that direction. All the three agree in this, that, when both eyes are directed to one ob- ject, they see it and the adjacent objects single; but, when they squint, they see objects sometimes single and sometimes double. I observed of all the three, that when they squinted most— that is, in the way they had been accustomed to the axes of their eyes converged so as to meet five or six inches before the nose. It is pro: OF SEEING. 173 bable that, in this case, the picture of the object in the diverging eye, must fall upon that part of the retina where the optic nerve enters; and, therefore, the object could not be seen by that eye. All the three have some defect in the sight of one eye, which none of them knew until I put them upon making trials ; and when they squint, the best eye is always directed to the object, and the weak eye is that which diverges from it. But when the best eye is covered, the weak eye is turned directly to the object. Whether this defect of sight in one eye, be the effect of its hav- ing been long disused, as it must have been when they squinted ; or whether some ori- ginal defect in one eye might be the occasion of their squinting, time may discover. The two brothers have found the sight of the weak eye improved by using to read with it while the other is covered. The elder can read an ordinary print with the weak eye ; the other, as well as the third gentleman, can only read a large print with the weak eye. I have met with one other person only who squinted, and yet could read a large print with the weak eye. He is a young man, whose eyes are both tender and weak-sighted, but the left much weaker than the right. When he looks at any object, he always directs the right eye to it, and then the left is turned towards the nose so much that it is impossible for him to see the same object with both eyes at the same time. When the right eye is covered, he turns the left directly to the object ; but he sees it indistinctly, and as if it had a mist about it. I made several experiments, some of them in the company and with the assistance of an ingenious physician, in order to discover whether objects that were in the axes of the two eyes, were seen in one place confounded together, as in those who have no involun- tary squint. The object placed in the axis of the weak eye was a lighted candle, at the distance of eight or ten feet. Before the other eye was placed a printed book, at such a distance as that he could read upon it. He said, that while he read upon the book, he saw the candle but very faintly. And from what we could learn, these two objects did not appear in one place, but had all that angular distance in appearance which they had in reality.* If this was really the case, the conclusion to be drawn from it is, that the correspond- ing points in his eyes are not situate in the same manner as in other men ; and that, if he could be brought to direct both eyes to one object, he would see it double. But, considering that the young man had never been accustomed to observations of this * See Weill— (" h» Essays," &c., p. 26.)— H. kind, and that the sight of one eye was so imperfect, I do not pretend to draw this conclusion with certainty from this single instance. All that can be inferred from these facts is, that, of four persons who squint, three appear to have nothing preternatural in the structure of their eyes. The centres of their retinas, and the points similarly situate with regard to the centres, do certainly corre- spond in the same manner as in other men — so that, if they can be brought to the habit of directing their eyes right to an object, they will not only remove a deformity, but improve their sight. With regard to the fourth, the case is dubious, with some pro- bability of a deviation from the usual course of nature in the situation of the correspond- ing points of his eyes. Seotion XVII. OF THE EFFECT OF CUSTOM IN SEEING OBJECTS SINGLE. It appears from the phaenomena of single and double vision, recited in § 13, that our seeing an object single with two eyes, depends upon these two things : — First, Upon that mutual correspondence of certain points of the retina which we have often described ; Secondly, Upon the two eyes being directed to the object so accurately that the two images of it fall upon corre- sponding points. These two things must concur in order to our seeing an object single with two eyes ; and, as far as they depend upon custom, so far only can single vision depend upon custom. With regard to the second — that is, the accurate direction of both eyes to the ob- ject — I think it must be acknowledged that this is only learned by custom. Na- ture hath wisely ordained the eyes to move in such manner that their axes shall always be nearly parallel ; but hath left it in our power to vary their inclination a little, according to the distance of the ob- ject we look at. Without this power, objects would appear single at one parti- cular distance only ; and, at distances much less or much greater, would always appear double. The wisdom of nature is conspi- cuous in giving us this power, and no less conspicuous in making the extent of it ex- actly adequate to the end. The parallelism of the eyes, in general, is therefore the work of nature ; but that precise and accurate direction, which must be varied according to the distance of the object, is the effect of custom. The power which nature hath left us of varying the inclination of the optic axes a little, is turned into a habit of giving them always 174 OF THE HUMAN MIND. that inclination which is adapted to the distance of the object. But it may be asked, What gives rise to this habit ? The only answer that can be given to this question is, that it is found necessary to perfect and distinct vision. A man who hath lost the sight of one eye, very often loses the habit of directing it exactly to the object he looks at, because that habit is no longer of use to him. And if he should recover the sight of his eye, he would recover this habit, by finding it useful. No part of the human constitution is more admirable than that whereby we acquire habits which are found useful, with- out any design or intention. Children must see imperfectly at first ; but, by using their eyes, they learn to use them in the best manner, and acquire, without intend- ing it, the habits necessary for that pur- pose. Every man becomes most expert in that kind of vision which is most useful to him in his particular profession and man- ner of life. A miniature painter, or an engraver, sees very near objects better than a sailor ; but the sailor sees very distant objects much better than they. A person that is short-sighted, in looking at distant objects, gets the habit of contracting the aperture of his eyes, by almost closing his eyelids. Why ? For no other reason, but because this makes him see the object more distinct. In like manner, the reason why every man acquires the habit of direct- ing both eyes accurately to the object, must be, because thereby he sees it more per- fectly and distinctly. It remains to be considered, whether that correspondence between certain points of the retina, which is likewise necessary to single vision, be the effect of custom, or an original property of human eyes. A strong argument for its being an ori- ginal property, may be drawn from the habit, just now mentioned, of directing the eyes accurately to an object. This habit is got by our finding it necessary to perfect and distinct vision. But why is it neces- sary ? For no other reason but this, be- cause thereby the two images of the object falling upon corresponding points, the eyes assist each other in vision, and the object is seen better by both together, than it could be by one ; but when the eyes are not accurately directed, the two images of an object fall upon points that do not corre- spond, whereby the sight of one eye disturbs the sight of the other, and the object is seen more indistinctly with both eyes than it would be with one. Whence it is rea- sonable to conclude, that this correspond- ence of certain points of the retina, is prior to the habits we acquire in vision, and con- sequently is natural and original. We have all acquired the habit of directing our eyes always in a particular manner, which causes single vision. Now, if nature' hath ordained that we should have single vision only, when our eyes are thus directed, there is an ob- vious reason why all mankind should agree in the habit of directing them in this manner. But, if single vision is the effect of custom, any other habit of directing the eyes would have answered the purpose ; and no account can be given why this particular habit should be so universal ; and it must appear very strange, that no one instance hath been found of a person who had acquired the habit of seeing objects single with both eyes, while they were directed in any other man- ner.* The judicious Dr Smith, in his excellent system of optics, maintains the contrary opinion, and offers some reasonings and facts in proof of it. He agrees with Bishop Berkeley^ in attributing it entirely to cus- tom, that we see obj ects single with two eyes, as well as that we see objects erect by in- verted images. Having considered Bishop Berkeley's reasonings in the 1 1th section, we shall now beg leave to make some remarks on what Dr Smith hath said upon this subject, with the respect due to an author to whom the world owes, not only many valuable discoveries Of Ins own, but those of the brightest mathematical genius of this age, which, with great labour, he generously redeemed from oblivion. He observes, that the question, Why we see objects single with two eyes ? is of the same sort with this, Why we hear sounds single with two ears ? — and that the same answer must serve both. The inference intended to be drawn from this observation is, that, as the second of these phsenomena is the effect of custom, so likewise is the first. Now, I humbly conceive that the ques- tions are not so much of the same sort, that the same answer must serve for both ; and, moreover, that our hearing single with two ears, is not the effect of custom. * This objection did not escape Dr Smith himself; but Reid seems to have overlooked his answer. *' When we view," he says, " an abject steadily, we have acquired a habit of directing the optic axes to the point in view ; because its pictures, falling upon the middle points of the retinas, are then distincter than if they fell upon any other places ; and, since the pictures of the whole object are equal to one another, and are both inverted with respect to the optic axes, it follows that the pictures of any col- lateral point are painted upon corresponding points of the retinas." This answer is rendered more plausible from the subsequent anatomical discovery of Soemmering. He found that, in that part of the retina which lies at the axis of the eye, there is, in man, and in other animals of acute vision, an 'opening, real or appar- ent, (foramen centrale,) the dimensions of which are such that the images of distincter vision would seem to be enclosed within it H. t This is an inadvertency. Berkeley hazards no such opinion in any of his works.— H. OF SEEING. 175 Two or more visible objects, although perfectly similar, and seen at the very same time, may be distinguished by their visible places; but two sounds perfectly similar, and heard at the same time, cannot be dis- tinguished ; for, from the nature of sound, the sensations they occasion must coalesce into one, and lose all distinction. If, there- fore, it is asked, Why we hear sounds single with two ears ? I answer, Not from custom ; but because two sounds which are perfectly like and synchronous, have nothing by which they can be distinguished. But will this answer fit the other question ? I think not. The object makes an appearance to each eye, as the sound makes an impression upon each ear : so far the two senses agree. But the visible appearances may be distin- guished by place, when perfectly like in other respects ; the sounds cannot be thus dis- tinguished : and herein the two senses dif- fer. Indeed, if the two appearances have the same visible place, they are, in that case, as incapable of distinction as the sounds were, and we see the object single. But when they have not the same visible place, they are perfectly distinguishable, and we see the object double. We see the object single only, when the eyes are directed in one particular manner; while there are many other ways of directing them within the sphere of our power, by which we see the object double. Dr Smith justly attributes to custom that well-known fallacy in feeling, whereby a button pressed with two opposite sides of two contiguous fingers laid across, is felt double. I agree with him, that the cause of this appearance is, that those opposite sides of the fingers have never been used to feel the same object, but two different objects, at the same time. And I beg leave to add, that, as custom produces this phse- nomenon, so a contrary custom destroys it ; for, if a man frequently accustoms himself to feel the button with his fingers across, it will at last be felt single ; as I have found by experience. It may be taken for a general rule, that things which are produced by custom, may be undone or changed by disuse, or by a contrary custom. On the other hand, it is a strong argument, that an effect is not owing to custom, but to the constitution of nature, when a contrary custom, long continued, is found neither to change nor weaken it. I take this to be the best rule by which we can determine the question presently* under consideration. I shall, therefore, mention two facts brought by Dr Smith, to prove that the corresponding points of the retinue have been changed by * See note * at p. 96, a — H. custom ; and then I shall mention soma facts tending to prove, that there are cor- responding points of the retina of the eyes originally, and that custom produces no change in them. " One fact is related upon the authority of Martin Folkes, Esq., who was informed by Dr Hepburn of Lynn, that the Rev. Mr Foster of Clinch wharton, in that neighbour- hood, having been blind for some years of a gutta serena, was restored to sight by sali- vation ; and that, upon his first beginning to see, all objects appeared to him double ; but afterwards, the two appearances ap- proaching by degrees, he came at last to see single, and as distinctly as he did before he was blind." Upon this case, I observe, First, That it does not prove any change of the corre- sponding points of the eyes, unless we sup- pose, what is not affirmed, that Mr Foster directed his eyes to the object at first, when he saw double, with the same accuracy, and in the same manner, that he did afterwards, when he saw single. Secondly, If we should suppose this, no account can be given, why at first the two appearances should be seen at one certain angular distance rather than another ; or why this angular distance should gradually decrease, until at last the appear- ances coincided. How could this effect be produced by custom ? But, Thirdly, Every circumstance of this case may be accounted for on the supposition that Mr Foster had corresponding points in the retina of his eyes from the time he began to see, and that custom made no change with regard to them. We need only further suppose, what is common in such cases, that, by some years' blindness, he had lost the habit of directing his eyes accurately to an object, and that he gradually recovered this habit when he came to see. The second fact mentioned by Dr Smith, is taken from Mr Cheselden's " Anatomy," and is this : — " A gentleman who, from a blow on the head, had one eye distorted, foundeveryobjectappeardouble; but, byde- grees, the most familiar ones became single ; and, in time, all objects became so, without any amendment of the distortion." I observe here, that it is not said that the two appearances gradually approached, and at last united, without any amendment of the distortion. This would indeed have been a decisive proof of a change in the corresponding points of the retina, and yet of such a change as could not be accounted for from custom. But this is not said ; and, if it had been observed, a circumstance so remarkable would have been mentioned by Mr Cheselden, as it was in the other case by Dr Hepburn. We may, therefore, take it for granted, that one of the appearances vanished by degrees, without approaching to 176 OF THE HUMAN MIND. the other. And this I conceive might hap- pen several ways. First, The sight of the distorted eye might gradually decay by the hurt ; so the appearances presented by that eye would gradually vanish. Secondly, A small and unperceived change in the man- ner of directing the eyes, might occasion his not seeing the object with the dis- torted eye, as appears from § 15, Art. 10. Thirdly, By acquiring the habit of direct- ing one and the same eye always to the ob- ject, the faint and oblique appearance pre- sented by the other eye, might be so little attended to when it became familiar, as not to be perceived. One of these causes, or more of them concurring, might produce the effect mentioned, without any change of the corresponding points of the eyes. For these reasons, the facts mentioned by Dr Smith, although curious, seem not to be decisive. The following facts ought to be put in the opposite scale. First, in the famous case of the young gentleman couched by Mr Cheselden, after having had cataracts on both eyes untilhe was [above] thirteen years of age, it appears that he saw objects single from the time he began to see with both eyes. Mr Cheselden's words are, "And now, being lately couched of his other eye, he says, that objects, at first, appeared large to this eye, but not so large as they did at first to the other ; and, looking upon the same object with both eyes, he thought it looked about twice as large as with the first couched eye only, hut not double, that we can anywise discover." Secondly, The three young gentlemen mentioned in the last section, who had squinted, as far as I know, from infancy, as soon as they learned to direct both eyes to an obj ect, saw it single. In these four cases, it appears evident that the centres of the retince corresponded originally, and before custom could produce any such effect ; for Mr Cheselden's young gentleman had never been accustomed to see at all before he was couched ; and the other three had never been accustomed to direct the axes of both eyes to the object. Thirdly, from the facts recited in § 13, it appears, that, from the time we are capable of observing the phsenomena of single and double vision, custom makes no change in them. I have amused myself with such observ- ations for more than thirty years ; and in every case wherein I saw the object double at first, I see it so to this day, notwith- standing the constant experience of its being single. In other cases, where I know there are two objects, there appears only one, after thousancls^pf experiments. Let a man look at a familiar object through a polyhedron, or multiplying-glass, every hour of his life, the number of visibU. appearances will be the same at last as at first ; nor does any number of experiments, or length of time, make the least change. Effects produced by habit, must vary according as the acts by which the habit is acquired are more or less frequent ; but the phsenomena of single and double vision are so invariable and uniform in all men, are so exactly regulated by mathematical rules, that I think we have good reason to conclude that they are not the effect of cus- tom, but of fixed and immutable laws of nature. Section XVIII. or DR porterfield's account op single AND DOUBLE VISION. Bishop Berkeley and Dr Smith seem to attribute too much to custom in vision, Dr Porterfield too little. This ingenious writer thinks, that, by an original law of our nature, antecedent to custom and experience, we perceive visible objects in their true place, not only as to their direction, but likewise as to their dis- tance from the eye ; and, therefore, he accounts for our seeing objects single, with two eyes, in this manner. Having the faculty of perceiving the object with each eye in its true place, we must perceive it with both eyes in the same place; and, consequently, must perceive it single. He is aware that this principle, although it accounts for our seeing objects single with two eyes, yet does not at all account for our seeing objects double ; and, whereas other writers on this subject take it to be a sufficient cause for double vision that we have two eyes, and only find it difficult to assign a cause for single vision, on the contrary, Dr Porterfield's principle throws all the difficulty on the other side. Therefore, in order to account for the phsenomena of double vision, he advances another principle, without signifying whe- ther he conceives it to be an original law of our nature, or the effect of custom. It is, That our natural perception of the distance of objects from the eye, is not extended to all the objects that fall within the field of vision, but limited to that which we directly look at ; and that the circumjacent objects, whatever be their real distance, are seen at the same distance with the object we look at ; as if they were all in the surface of a sphere, whereof the eye is the centre. Thus, single vision is accounted for by our seeing the true distance of an object which we look at ; and double vision, by a false appearance of distance in objects which we do not directly look at. OF SEEING. 177 We agree with this .earned and inge- nious author, that it is by a natural and original principle that we see visible objects in a certain direction from the eye, and honour him as the author of this discovery :* but we cannot assent to either of those principles by which he explains single and double vision— for the following reasons : — 1. Our having a natural and original perception of the distance of objects from the eye, appears contrary to a well-attested fact : for the young gentleman couched by Mr Cheselden imagined, at first, that what- ever he saw touched his eye, as what he felt touched his hand.-f 2. The perception we have of the distance of objects from the eye, whether it be from nature or custom, is not so accurate and determinate as is necessary to produce sin- gle vision. A mistake of the twentieth or thirtieth part of the distance of a small object, such as a pin, ought, according to Dr Porterfield's hypothesis, to make it ap- pear double. Very few can judge of the distance of a visible object with such accuracy. Yet we never find double vision produced by mistaking the distance of the object. There are many cases in vision, even with the naked eye, wherein we mis- take the distance of an object by one half or more : why do we see such objects single ? When I move my spectacles from my eyes toward a small object, two or three feet dis- tant, the object seems to approach, so as to be seen at last at about half its real distance ; but it is seen single at that apparent distance, * To this honour Porterfield has no title. The law of Me line of visible direction, was a-common theory long' before the publication of Jiis writings j for it was maintained by Kepler, Gassendi, Scheiner, Rohault, Regis, Du Hamel, Mariotte, De Chales, Musschen- broek, Molyneux, &c. &c, and many of these main- tained -that this law was an original principle or in. stitution of our nature. — H. + We must be careful not, like Reid and,philo- sophersin general, to confound the perceptions of mere externality or outness, and the knowledge 'we have of. distance, through the eye. The former may he, and probably is, natural; while the latter, in a iire.it but unappretiable measure, is acquired. In the case of Cheselden— that in which the blindness pre. vious to the recovery of eight was most perfect, and, therefore, the most instructive upon record — the patient, though he had little or no perception of distance, i. e. of the degree of externality, had still a perception of that externality absolutely. The objects, he said, seemed to " touch his eyes, as what he felt did his skin j" but they did not appear to him as if in his eyes, far less as a mere affection of the or- gan. This, however, is erroneously assumed by Mr Fearn. This natural perception of Outness, which is the foundation of our acquired- knowledge of dis. tance, seems given us in the'natura! perception we have .of the direction of the rays of light. In like manner, we must not confound, as is com- monly done, the fact of the eye affording us a per- ception of extension and plain-figure, or outline, in thaperception -of colours, and the fact of its being the vehicle of intimations in regard to the compa- rative magnitude and cubical forms of the objects from which these rays proceed. The-one is a know- ledge by sense — natural, immediate, and infallible ; the other, like that of distance, is, by inference, ac- quired, mediate, and at best always insecure.— H. as well as when we see it with the naked eye at its real distance. And when we look at an object with a binocular telescope, pro- perly fitted to the eyes, we see it single, while it appears fifteen or twenty times nearer than it is. There are then few cases wherein the distance of an object from the eye is seen so accurately as is necessary for single vision, upon this hypothesis : this seems to be a conclusive argument against the account given of single vision. We find, likewise, that false judgments or fallacious appearances of the distance of an object, do not produce double vision : this seems to be a conclusive argument against the account given of double vision. 3. The perception we have of the linear distance of objects seems to be wholly the effect of experience. This, I think, hath been proved by Bishop Berkeley and by Dr Smith ; *and when we come to point out the means of judging of distance by sight, it will appear that they are all furnished by experience. 4. Supposing that, by a law of our nature, the distance of objects from the eye were perceived most accurately, as well as their direction, it will not follow that we must see the object single. Let us consider what means such a law of nature would furnish for resolving the question, Whether the objects of the two eyes are in one and the same place, and consequently are not two, but one ? Suppose, then, two right lines, one drawn from the centre of one eye to its object, the other drawn, in like manner, from the centre of the other eye to its object. This law of nature gives us the direction or position of each of these right lines, and the length of each ; and this is all that it gives. These are geometrical data, and we may learn from geometry what is determined by their means. Is it, then, determined by these data, Whe- ther the two right lines terminate in one and the same point, or not ? No, truly. In order to determine this, we must have three other data. We must know whether the two right lines are in one plane ; we must know what angle they make ; and we must know the distance between the centres of the eyes. And when these things are known, we must apply the rules of trigono- metry, before we can resolve the question, Whether the objects of the two eyes are in one and the same place ; and, consequently, whether they are two or one ? 5. That false appearance of distance into which double vision is resolved, cannot be the effect of custom, for constant experience contradicts it. Neither hath it the features of a law of nature, because it does not answer any good purpose, nor, indeed, any purpose at all, but to deceive us. But why should we seek for arguments, in a question N 178 OF THE HUMAN MIND. concerning what appears to us, or does not appear ? The question is, At what distance do the objects now in my eye appear ? Do they all appear at one distance, as if placed in the concave surface of a sphere, the eye being in the centre ? Every man, surely, may know this with certainty ; and, if he will but give attention to the testimony of his eyes, needs not ask a philosopher how visible objects appear to him. Now, it is very true, that, if I look up to a star in the heavens, the other stars that appear at the same time, do appear in this manner : yet this phsenomenon does not favour Dr Por- terfield's hypothesis ; for the stars and heavenly bodies do not appear at their true distance's when we look directly to them, any more than when they are seen obliquely : a id if this phsenomenon be an argument for Dr Portorfield's second principle, it must destroy the first. The true cause of this pheenomenon will be given afterwards ; therefore, setting it aside for the present, let us put, another case. I sit in my room, and direct my eyes to the door, which appears to be about sixteen feet distant : at the same time, I see many other objects faintly and obliquely — the floor, floor-cloth, the table which I write upon, papers, standish, candle, &c. Now, do all these objects ap- pear at the same distance of sixteen feet ? Upon the closest attention, I find they do not. Section XIX. of dr briggs's theory, and sir isaac newton's conjecture on this sub- ject. I am afraid the reader, as well as the writer, is already tired of the subject of single and double vision. The multitude of theories advanced by authors of great name, and the multitude of facts, observed without sufficient skill in optics, or related without attention to the most material and decisive circumstances, have equally contri- buted to perplex it. In order to bring it to some issue, I have, in the 13th section, given a more full and regular deduction than had been given heretofore, of the phaenomena of single and double vision, in those whose sight is per- fect ; and have traced them up to one ge- neral principle, which appears to be a law of vision in human eyes that are perfect and in their natural state. In the 14th section, I have made it ap- pear, that this law of vision, although ex- cellently adapted to the fabric of human eyes, cannot answer the purposes of vision in some other animals ; and therefore, very probably, is not common to all animals. The purpose of the 15th and 16th sections is, to inquire, Whether there be any de- viation from this law of vision in those who squint ? — a question which is of real importance in the medical art, as well as in the philosophy of vision; but which, after all that hath been observed and written on the subject, seems not to be ripe for a determination, for want of pro- per observations. Those who have had skill to make proper observations, have wanted opportunities ; and those who have had opportunities, have wanted skill or attention. I have therefore thought it worth while to give a distinct account of the observations necessary for the deter- mination of this question, and what con- clusions may be drawn from the facts ob- served. I have likewise collected, and set in one view, the most conclusive facts that have occurred in authors, or have fallen under my own observation. It must be confessed that these facts, when applied to the question in hand, make a very poor figure ; and the gentlemen of the medical faculty are called upon, for the honour of their profession, and for the bene- fit of mankind, to add to them. All the medical, and all the optical writers upon the strabismus that I have met with, except Dr Jurin, either affirm, or take it for granted, that squinting persons see the object with both eyes, and yet see it single. Dr Jurin affirms that squinting persons never see the object with both eyes ; and that, if they did, they would see it double. If the common opinion be true, the cure of a squint would be as pernicious to the sight of the patient, as the causing of a perma- nent squint would be to one who naturally had no squint ; and, therefore, no physi- cian ought to attempt such a cure, no patient ought to submit to it. But, if Dr .Turin's opinion be true, most young people that squint may cure themselves, by taking some pains ; and may not only remove the deformity, but, at the same time, improve their sight. If the common opinion be true, the centres, and other points of the two retina, in squinting persons, do not corre- spond, as in other men, and Nature, in them, deviates from her common rule. But, if Dr Jurin's opinion be true, there is reason to think that the same general law of vision which we have found in perfect human eyes, extends also to those which squint. It is impossible to determine, by reason- ing, which of these opinions is true; or whether one may not be found true in some patients, and the other in others. Here, experience and observation are our only guides ; and a deduction of instances is the only rational argument. It might, there- fore, have been exuected, that the patrons OF SEEING. 179 of the contrary opinions should have given instances in support of them that are clear and indisputable ; but I have not found one such instance on either side of the question, in all the authors I have met with. I have given three instances from my own observ- ation, in confirmation of Dr Jurin's opinion, which admit of no doubt ; and one which leans rather to the other opinion, but is dubious. And here I must leave the matter to further observation. In thel7th section, I have endeavoured to shewthat the correspondence and [or] sym- pathy of certain points of the two retina, into which we have resolved all the phseno- mena of single and double vision, is not, as Dr Smith conceived, the effect of custom, nor can [it] be changed by custom, but is a natural and original property of human eyes ; and, in the last section, that it is not owing to an original and natural perception of the true distance of objects from the eye, as Dr Forterfield imagined. After this re- capitulation, which is intended to relieve the attention of the reader, shall we enter into more theories upon this subject ? That of Dr Briggs — first published in English, in the " Philosophical Transac- tions," afterwards in Latin, under the title of *' Nova Visionis Theoria," with a prefa- tory epistle of Sir Isaac Newton to the author — amounts to this, That the fibres of the optic nerves, passing from correspond- ing points of the retina to the thalami ner- vorum opticorum, having the same length, the same tension, and a similar situation, will have the same tone ; and, therefore, their vibrations, excited by the impression of the rays of light, will be like unisons in music, and will present one and the same image to the mind : but the fibres passing from parts of the retinm which do not cor- respond, having different tensions and tones, will have discordant vibrations ; and, there- fore, present different images to the mind. I shall not enter upon a particular exam- ination of this theory. It is enough to ob- serve, in general, that it is a system of con- jectures concerning things of which we are entirely ignorant ; and that all such theories in philosophy deserve rather to be laughed at, than to be seriously refuted. From the first dawn of philosophy to this day, it hath been believed that the optic nerves are intended to carry the images of visible objects from the bottom of the eye to the mind ; and that the nerves belonging to the organs of the other senses have a like office. * But how do we know this ? We conjecture it ; and, taking this conjecture for a truth, we consider how the nerves may best answer this purpose. The system of the nerves, for many ages, was taken to be a • This statement is far too unqualified H'. hydraulic engine, consisting of a bundle of pipes, which carried to and fro a liquor called animal spirits. About the time of Dr Briggs, it was thought rather to be a stringed instrument, composed of vibrating chords, each of which had its proper tension and tone. But some, with as great probability, conceived it to be a wind instrument, which played its part by the vibrations of an elastic aether in the nervous fibrils. These, I think, are all the engines into which the nervous system hath been moulded by philosophers, for conveying the images of sensible things from the organ to the srnsorium. And, for all that we know of the matter, every man may freely choose which he thinks fittest for the purpose ; for, from fact and experiment, no one of them can claim preference to another. Indeed, they all seem so unhandy engines for carry- ing images, that a man would be tempted to invent a new one. Since, therefore, a blind man may guess as well in the dark as one that sees, I beg leave to offer another conjecture touching the nervous system, which, I hope, will answer the purpose as well as those we have mentioned, and which recommends itself by its simplicity. Why may not the optic nerves, for instance, be made up of empty tubes, opening their mouths wide enough to receive the rays of light which form the image upon the retina, and gently convey- ing them safe, and in their proper order, to the very seat of the soul, until they flash in her face ? It is easy for an ingenious phi- losopher to fit the caliber of these empty tubes to the diameter of the particles of light, so as they shall receive no grosser kind of matter ; and, if these rays should be in danger of mistaking their way, an expe- dient may also be found to prevent this ; for it requires no more than to bestow upon the tubes of the nervous system a peristal- tic motion, like that of the alimentary tube. It is a peculiar advantage of this hypo- thesis, that, although all philosophers be- lieve that the species or images of things are conveyed by the nerves to the soul, yet none of their hypotheses shew how this may be done. For how can the images of sound, taste, smell, colour, figure, and all sensible qualities, be made out of the vibra- tions of musical chords, or the undulations of animal spirits, or of aether ? We ought not to suppose means inadequate to the end. Is it not as philosophical, and more intelligible, to conceive, that, as the stomach receives its food, so the soul receives her images by a kind of nervous deglutition ? I might add, that we need only continue this peristaltic motion of the nervous tubes from the sensorium to the extremities of the nerves that serve the muscles, in order to account for muscular motion. n 3 180 OF THE HUMAN MIND. Thus Nature will be consonant to her- self ; and, as sensation will be the convey- ance of the ideal aliment to the mind, so muscular motion will be the expulsion of the recrementitious part of it. For who can deny, that the images of things con- veyed by sensation, may, after due con- coction, become fit to be thrown off by muscular motion ? I only give hints of these things to the ingenious, hoping that in time this hypothesis may be wrought up into a system as truly philosophical as that of ani- mal spirits, or the vibration of nervous fibres. To be serious : In the operations of na- ture, I hold the theories of a philosopher, which are unsupported by fact, in the same estimation with the dreams of a man asleep, or the ravings of a madman. We laugh at the Indian philosopher, who, to account for the support of the earth, contrived the hypothesis of a huge elephant, and, to support the elephant, a huge tortoise. If we will candidly confess the truth, we know as little of the operation of the nerves, as he did of the manner in which the earth is supported ; and our hypotheses about animal spirits, or about the tension and vibrations of the nerves, are as like to be true, as his about the support of the earth. His elephant was a hypothesis, and our hypotheses are elephants. Every theory in philosophy, which is built on pure con- jecture, is an elephant ; and every theory that is supported partly by fact, and partly by conjecture, is like Nebuchadnezzar's image, whose feet were partly of iron and partly of clay. The great Newton first gave an example to philosophers, which always ought to be, but rarely hath been followed, by distin- guishing his conjectures from his conclu- sions, and putting the former by themselves, in the modest form of queries. This is fair and legal ; but all other philosophical traf- fic in conjecture ought to be held contra- band and illicit. Indeed, his conjectures have commonly more foundation in fact, and more verisimilitude, than the dogma- tical theories of most other philosophers ; and, therefore, we ought not to omit that which he hath offered concerning the cause of our seeing objects single with two eyes, in the 15th query annexed to his "Optics." " Are not the species of objects seen with both eyes, united where the optic nerves meet before they come into the brain, the fibres on the right side of both nerves uniting there, and after union going thence into the brain in the nerve which is on the right side of the head, and the fibres on the left side of both nerves uniting in the same place, and after union going into the brain in the nerve which is on the left side of the head, and these two nerves meeting iu the brain in such a mnnner that their fibres . make but one entire species or picture, half of which on the right side of the sensorium comes from the right side of both eyes through the right side of both optic nerves, to the place where the nerves meet, and from thence on the right side of the head into the brain, and the other half on the left side of the sensorium comes, in like manner, from the left side of both eyes ? For the optic nerves of such animals as look the same way with both eyes (as men, dogs, sheep, oxen, &c.) meet before they come into the brain ; but the optic nerves of such animals as do not look the same way with both eyes (as of fishes, and of the chameleon) do not meet, if I am rightly in- formed." I beg leave to distinguish this query into two, which are of very different natures ; one being purely anatomical, the other re- lating to the carrying species or pictures of visible objects to the sensorium. The first question is, Whether the fibres coming from corresponding points of the two retina do not unite at the place where the optic nerves meet, and continue united from thence to the brain ; so that the right optic nerve, after the meeting of the two nerves, is composed of the fibres coming from the right side of both retina, and the left, of the fibres coming from the left side of both retina ? This is undoubtedly a curious and rational question ; because, if we could find ground from anatomy to answer it in the affirm- ative, it would lead us a step forward in discovering the cause of the correspondence and sympathy which there is between cer- tain points of the two retina. For, although we know not what is the particular function of the optic nerves, yet it is probable that some impression made upon them, and communicated along their fibres, is neces- sary to vision ; and, whatever be the nature of this impression, if two fibres are united into one, an impression made upon one of them, or upon both, may probably produce the same effect. Anatomists think it a sufficient account of a sympathy between two parts of the body, when they are served by branches of the same nerve ; we should, therefore, look upon it as an important dis- covery in anatomy, if it were found that the same nerve sent branches to the corre- sponding points of the retina. But hath any such discovery been made ? No, not so much as in one subject, as far as I can learn ; but, in several subjects, the contrary seems to have been discovered. Dr Porterfield hath given us two cases at length from Vesalius, and one from Ctesal- pinus, wherein the optic nerves, after touch . ing one another as usual, appeared to be reflected back to the same side whence the* came without any mixture of theii OF SEEING. 181 fibres. Each of these persons had lost an eye some time before his death, and the optic nerve belonging to that eye was shrunk, so that it could be distinguished from the other at the place where they met. Another case, which the same author gives from Vesalius, is still more remarkable; for in it the optic nerves did not touch at all ; and yet, upon inquiry, those who were most familiar with the person in his life- time, declared that he never complained of any defect of sight, or of his seeing objects double. Diemerbroeck tells us, that Aqua- pendens [ab Aquapendente] and Valverda likewise affirm, that they have met with subjects wherein the optic nerves' did not touch." As these observations were made before Sir Isaac Newton put this query, it is un- certain whether he was ignorant of them, or whether he suspected some inaccu- racy in them, and desired that the matter might be more carefully examined. But, from the following passage of the most accurate Winslow, it does not appear that later observations have been more favour- able to his conjecture. " The union of these (optic) nerves, by the small curva- tures of their corri.ua, is very difficult to be unfolded in human bodies. This union is commonly found to be very close ; but, in some subjects, it seems to be no more than a strong adhesion — in others, to be partly made by an intersection or crossing of fibres. They have been found quite separate ; and, in other subjects, one of them has been found to be very much altered both in size and colour through its whole passage, the other remaining in its natural state." When we consider this conjecture of Sir Isaac Newton by itself, it appears more ingenious, and to have more verisimilitude, than anything that has been offered upon the subject ; and we admire the caution and modesty of the author, in proposing it only as a subject of inquiry : but when we compare it with the observations of anato- mists which contradict it,+ we are naturally *■ See Meckel's " Pathologische Anatomie," I., p. 399.— H. + Anatomists are now nearly agreed, that, in the normal state, there is a partial decussation of the human optic nerve. Soemmering, Treviranus, Ku- dolphi, Johannes Mueller, Langenbeck, Magendie, Mayo, &c, are paramount authority for the fact. I dcnot know whether the observation has been made, that the degree of decussation in different animals is exactly in the inverse ratio of what we might have been led, at first sight, theoretically to anticipate.^ In proportion as the convergence .is complete—*'. e., where the axis of the field of vision of the severaTeyes coincides with the axis of the field of vision common to- both, as in men and apes — there we find the de- cussation most partial and obscure ; whereas, in the lower animals, in proportion as»we.find the fieldsof the two eyes exclusive of each other, and where, conse- quently, the necessity of bringing the two organs into unison -might seem abolished, there, howevpr, we find the crossing of the optic fibres complete. In fishes, accordingly! it is distinct and isolated ; in birds, it taker led to this reflection, That, if we trust to the conjectures of men of the greatest genius in the operations of nature, we have only the chance of going wrong in an inge- nious manner. The second part of the query is, Whether the two species of objects from the two eyes are not, at the place where the optic nerves meet, united into one species or picture, half of which is carried thence to the sen. sorium in the right optic nerve, and the other half in the left ? and whether these two halves are not so put together again at the sensorium, as to make one species or picture ? Here it seems natural to put the previous question, What reason have we to believe that pictures of objects are at all carried to the sensorium, either by the optic nerves, or by any other nerves ? Is it not possible that this great philosopher, as well as many of a lower form, having been led into this opinion at first by education, may have con- tinued in it, because he never thought of calling it in question ? I confess this was my own case for a considerable part of my life. But since I was led by accident to think seriously what reason I had to believe it, I could find none at all. It seems to be a mere hypothesis, as much as the Indian philosopher's elephant. I am not conscious of any pictures of external objects in my sensorium, any more than in my stomach : the things which I perceive by my senses, appear to be external, and not in any part of the brain ; and my sensations, properly so called, have no resemblance of external objects. The conclusion from all that hath been said, in no less than seven sections, upon our seeing objects single with two. eyes, is this — That, by an original property of human eyes, objects painted upon the centres of the two retina, or upon points similarly situate with regard to the centres, appear in the same visible place ; that the most plausible attempts to account for this property of the eyes, have been unsuccess- ful ; and, therefore, that it must be either a primary law of our constitution, or the consequence of some more general law, which is not yet discovered. We have now finished what we intended to say, both of the visible appearances of things to the eye, and of the laws of our constitution by which those appearances more the appearance of an interlacement ; in the mammalia, that of a fusion of substance. A 6econd consideration, however, reconciles theory and observ- ation. Some, however, as Woolaston, make the parallel motion of the eyes to be dependent on the connection of the optic nerves ; and, besides experi. ments, there are various pathological ca*es in favoui of.-Magendie's opinion, that the fifth pair are the nerves on, which the energies of sight, hearing, smell, and' taste are proximately ana principally de. pendent. — H. 182 OF THE HUMAN MIND. arc exhibited. But it was observed, in the beginning \A this chapter, that the visible appearances of objects serve only as signs of' their distance, magnitude, figure, and other tangible qualities. The visible ap- pearance is that which is presented to the mind by nature, according to those laws of our constitution which have been explained, lint th^j thin;' 1 signified by that appearance, id that which is presented to the mind by custom. When one speaks to us in a language that is familiar, we hear certain sounds, and this is all the effect that his discourse has upon us by nature ; but by custom we understand the meaning of these sounds ; and, therefore, we fix our attention, not upon the sounds, but upon the things sig- nified by them. In like manner, we see only the visible appearance of objects by nature; but we learn by custom to inter- pret these appearances, and to understand their meaning. And when this visual language is learned, and becomes familiar, we attend only to the things signified ; and cannot, without great difficulty, attend to the signs by which they are presented. The mind passes from one to the other so rapidly and so familiarly, that no trace of the sign is left in the memory, and we seem immediately, and without the intervention of any sign, to perceive the thing sig- nified. When I look at the apple-tree which stands before my window, I perceive, at the first glance, its distance and magnitude, the roughness of its trunk, the disposition of its branches, the figure of its leaves and fruit. I seem to perceive all these things immediately. The visible appearance which presented them all to the mind, has entirely escaped me ; I cannot, without great diffi- culty, and painful abstraction, attend to it, even when it stands before me. Yet it is certain that this visible appearance only is presented to my eye by nature, and that I learned by custom to collect all the rest from it. If I had never seen before now, I should not perceive either the distance or tangible figure of the tree ; and it would have required the practice of seeing for many months, to change that original per- ception which nature gave me by my eyes, into that which I now have by custom. The objects which we see naturally and originally, as hath been before observed, have length and breadth, but no thickness nor distance from the eye. Custom, by a kind of legerdemain, withdraws gradually these original and proper objects of sight, and substitutes in their place objects of touch, which have length, breadth, and thickness, and a determinate distance from the eye. By what means this change is brought about, and what principles of the human mind concur in it, we are next to inquire. Section XX, OF PERCEPTION IN GENERAL. Sensation, and the perception-}- of exter- nal objects by the senses, though very dif- ferent in their nature, have commonly been considered as one and the same thing.£ The purposes of common life do not make it necessary to distinguish them 5 and the received opinions of philosophers tend ra- ther to confound them ; but, without at- tending carefully to this distinction, it is impossible to have any just conception of the operations of our senses. The most simple operations of the mind, admit not of a logical definition : all we can do is to de- scribe them, so as to lead those who are conscious of them in themselves, to attend to them, and reflect upon them ; and it is often very difficult to describe them so as to answer this intention. The same mode of expression is used to denote sensation and perception ; and, there- fore, we are apt to look upon them as things of the same nature. Thus, I feel a pain ; I see a tree : the first denoteth a sensation, the last a perception. The grammatical analysis of both expressions is the same : • Nothing in the compass of inductive reasoning appears more satisfactory than Berkeley's demon- stration of the necessity and manner of our learn, ing, by a slow processof observation and comparison alone, the connection between the perceptions of vision and touch, and, in general, all that relates to the distance and real magnitude of external things. But, although the same necessity seems in theory equally incumbent on thelower animals as on man, yet this theory is provokingly— and that by the most manifest experience— found totally at fault with re- gard to them ; for we find that ,all the animals who possess at birth the power of regulated motion (and these are those only through whom the truth of the theory canbe brought to the test of a decisive ex- periment) possess also from birth the whole appre- hension of distance, &c , which they are ever known to exhibit. The solution of this difference, by a resort to instinct, is unsatisfactory ; for instinct is, in fact, an occult principle— a kind of natural revel- ation— and the hypothesis of instinct, therefore, only a confession of our ignorance ; and, at the same time, if instinct he allowed in the lower animals, how can we determine whether and how far instinct may not in like manner operate to the same result in man ?— I have discovered, and, by a wide indue tion, estaLlished, that the power ot regulated mo- tion at birth is, in all animals, governed by the de- velopement, at that period, of the cerebellum, in pro. por tion to the brain proper. Is this law to be extended to the faculty of determiningdistances, &c, by sight ? f On the distinction of Sensation proper^ from Perception proper, see « Essays on the Intellectual Powers," Essay II., chap. 16, and Note I).* Reid himself, especially in this work, has not been always rigid in observing their discrimination.— H. J Not only are they different, but— what has escaped our philoaophen-the law ot their manifestation is, that, while both are co-existent, each is always in the inverse ratio of the other. Perception is theobjec. tive, bensation the subjective, element. This by the OK SEEING. 183 for both consist of an active verb and an object. But, if we attend to the things sig- nified by these expressions, we shall find that, in the first, the distinction between the act and the object is not real but gramma- tical ; in the second, the distinction is not only grammatical but real. The form of the expression, I feel pain, might seem to imply that the feeling is something distinct from the pain felt ; yet, in reality, there is no distinction. As thinking a thought is an expression which could signify no more than thinking, so feeling a pain signifies no more than being pained. What we have said of pain is ap- licable to every other mere sensation. It is difficult to give instances, very few of our sensations having names ; and, where they have, the name being common to the sensation, and to something else which is associated with it. But, when we attend to the sensation by itself, and separate it from other things which are conjoined with it in the imagination, it appears to be something which can have no existence but in a sentient mind, no distinction from the act of the mind by which it is felt. Perception, as we here understand it, hath always an object distinct from the act by which it is perceived; an object which may exist whether it be perceived or not. I perceive a tree that grows before my win- dow ; there is here an object which is per- ceived, and an act of the mind by which it is perceived ; and these two are not only distinguishable, but they are extremely un- like in their natures. The object is made up of a trunk, branches, and leaves ; but the act of the mind by which it is per- ceived hath neither trunk, branches, nor leaves. I am conscious of this act of my mind, and I can reflect upon it ; but it is too simple to admit of an analysis, and I cannot find proper words to describe it. I find nothing that resembles it so much as the remembrance of the tree, or the ima- gination of it. Yet both these differ essen- tially from perception ; they differ likewise one from another. It is in vain that » philosopher assures me, that the imagina- tion of the tree, the remembrance of it, and the perception of it, are all one, and differ only in degree of vivacity. I know the contrary ; for I am as well acquainted with all the three as I am with the apartments of my own house. I know this also, that the perception of an object implies both a conception of its form, and a belief of its present existence.* I know, moreover, that * It is to be observed that Reid himself does not discriminate perception and imagination by any essential difference. According to him, perception is only the conception (imagination) of an object, ac- companied with a belief of its present existence; and even this last distinction, a mere " faith without this belief is not the effect of argumentation and reasoning ; it is the immediate effect of my constitution. I am aware that this belief which I have in perception stands exposed to the strongest batteries of scepticism. But they make no great impression upon it. The sceptic asks me, Why do you believe the existence of the external object which you perceive ? This belief, sir, is none of my manufacture ; it came from the mint of Nature 5 it bears her image and superscription ; and, if it is not right, the fault is not mine : I even took it upon trust, and without suspicion. Kea- son, says the sceptic, is the only judge 01 truth, and you ought to throw off every opi- nion and every belief that is not grounded on reason. Why, sir, should I believe the faculty of reason more than that of percep- tion ? — they came both out of the same shop, and were made by the same artist ; and if he puts one piece of false ware into my hands, what should hinder him from put- ting another ?* Perhaps the sceptic will agree to distrust reason, rather than give any credit to per- ception. For, says he, since, by your own concession, the object which you perceive, and that act of your mind by which you perceive it, are quite different things, the one may exist without the other ; and, as the object may exist without being per- ceived, so the perception may exist without an object. There is nothing so shameful in a philosopher as to be deceived and de- luded ; and, therefore, you ought to resolve firmly to withhold assent, and to throw off this belief of external objects, which may be all delusion. For my part, I will never attempt to throw it off ; and, although the sober part of mankind will not be very anxious to know my reasons, yet, if they can be of use to any sceptic, they are these : — First, because it is not in my power : why, then, should I make a vain attempt ? It would be agreeable to fly to the moon, and to make a visit to Jupiter and Saturn ; but, when I know that Nature has bound me down by the law of gravitation to this planet which I inhabit, I rest contented, aud quietly knowledge," is surrendered by Mr Stewart. Now, as conception (imagination) is only inriediately cog- nisant of the ego, so must perception or. tl is doctrine be a knowledge purely subjective. Perception must be wholly different in kind from Conception, if we are to possess a faculty informing us of the existent e and qualities of an external world ; and, unless we are possessed of such a faculty, we shall never be compe- tent to vindicate more than an ideal reality to the objects of our cognitions. — H. * This argument would be good in favour of our belief, that we are really percipient of a non-rgo : it is not good in favour of our belief that a ?>crn-<'go really exists, our perception of its re. 1 exi tence being abandoned. Mankind have the latter belief only as they have the former ; and, if we are dei eivcti by our Nature touching the one, it is absurd to ap peal to her veracity in proof of Hie other. — H. 184 OF THE HUMAN MIND. suffer myself to be carried along in its orbit. My belief is carried along by perception, as irresistibly as my body by the earth. And the greatest sceptic will find himself to be in the same condition. He may struggle hard to disbelieve the informations of his senses, as a man does to swim against a tor- rent ; but, ah I it is in vain. It is in rain that he strains every nerve, and wrestles with nature, and with every object that strikes upon his senses. For, after all, when his strength is spent in the fruitless attempt, he will be carried down the tor- rent with the common herd of believers. Secondly, I think it would not be pru- dent to throw off this belief, if it were in my power. If Nature intended to deceive me, and impose upon me by false appear- ances, and I, by my great cunning and pro- found logic, have discovered the imposture, prudence would dictate to me, in this case, even to put up [with] this indignity done me, as quietly as I could, and not to call her an impostor to her face, lest she should be even with me in another way. For what do I gain by resenting this injury ? You ought at least not to believe what she says. This indeed seems reasonable, if she intends to impose upon me. But what is the consequence ? I resolve not to be- lieve my senses. I break my nose against a post that comes in my way ; I step into a dirty kennel ; and, after twenty such wise and rational actions, I am taken up and clapped into a mad-house. Now, I con- fess I would rather make one of the credu- lous fools whom Nature imposes upon, than of those wise and rational philosophers who resolve to withhold assent at all this expense. If a man pretends to be a scep- tic with regard to the informations of sense, and yet prudently keeps out of harm's way as other men do, he must excuse my suspicion, that he either acts the hypocrite, or imposes upon himself. For, if the scale of his belief were so evenly poised as to lean no more to one side than to the con- trary, it is impossible that his actions could be directed by any rules of common prudence. * Thirdly, Although the two reasons al- ready mentioned are perhaps two more than enough, I shall offer a third. I gave im- plicit belief to the informations of Nature by my senses, for a considerable part of my life, before I had learned so much logic as to be able to start a doubt concerning them. And now, when I reflect upon what is past, I do not find that I have been imposed upon by this belief. I find that without it I must have perished by a thousand accidents. I find that without it I should have been no wiser now than when I was born. I should * This is not a fair consequence of Idealism ; there- fore, it is not a reduetio ad aCsurdttm.—H. not even have been able to acquire that logic which suggests these sceptical doubts with regard to my senses. Therefore, I consider this instinctive belief as one of the best gifts of Nature. I thank the Author of my being, who bestowed it upon me before the eyes of my reason were opened, and still bestows it upon me, to be my guide where reason leaves me in the dark. And now I yield to the direction of my senses, not from instinct only, but from confidence and trust in a faithful and beneficent Moni- tor, grounded upon the experience of his paternal care and goodness. In all this, I deal with the Author of my being, no otherwise than I thought it reason- able to deal with my parents and tutors. I believed by instinct whatever they told me, long before I had the idea of a he, or thought of the possibility of their deceiving me. Afterwards, upon reflection, I found they had acted like fair and honest people, who wished me well. I found that, if I had not believed what they told me, before I could give a reason of my belief, I had to this day been little better than a changeling. And although this natural credulity hath some- times occasioned my being imposed upon by deceivers, yet it hath been of infinite advantage to me upon the whole ; therefore, I consider it as another good gift of Nature. And I continue to give that credit, from reflection, to those of whose integrity and veracity I have had experience, which be- fore I gave from instinct. There is a much greater similitude than is commonly imagined, between the testi- mony of nature given by our senses, and the testimony of men given by language. The credit we give to both is at first the effect of instinct* only. When we grow up, and begin to reason about them, the credit given to human testimony is re- strained and weakened, by the experience we have of deceit. But the credit given to the testimony of our senses, is established and confirmed by the uniformity and con- stancy of the laws of nature. Our perceptions are of two kinds : some are natural and original ; others acquired, and the fruit of experience. When I per- ceive that this is the taste of cyder, that of brandy ; that this is the smell of an apple, that of an orange ; that this is the noise of thunder, that the ringing of bells ; this the sound of a coach passing, that the voice of such a friend : these perceptions, and others of the same kind, are not original — they are acquired. But the perception which! have, by touch, of the hardness and softness of bodies, of their extension, figure, and mo- tion, is not acquired — it is original. * On the propriety of the term " instinct," see in Note A.— H. OF SEEING. 185 In all our senses, the acquired percep- tions are many more than the original, especially in sight. By this sense we per- ceive originally the visible figure and colour of bodies onlys and their visible place :* but we learn to perceive by the eye, almost everything which we can perceive by touch. The original perceptions of this sense serve only as signs to introduce the acquired. The signs by which objects are presented to us in perception, are the language of Nature to man ; and as, in many respects, it hath great affinity with the language of man to man, so particularly in this, that both are partly natural and original, partly acquired by custom. Our original or natural perceptions are analogous to the natural language of man to man, of which we took notice in the fourth chapter ; and our acquired perceptions are analogous to artificial language, which, in our mother- tongue, is got very much in the same man- ner with our acquired perceptions — as we shall afterwards more fully explain. Not only men, but children, idiots, and brutes, acquire by habit many perceptions which they had not originally. Almost every employment in life hath perceptions of this kind that are peculiar to it. The shepherd knows every sheep of his flock, as we do our acquaintance, and can pick them out of another flock one by one. The butcher knows by sight the weight and quality of his beeves and sheep before they are killed. The farmer perceives by his eye, very nearly, the quantity of hay in a rick, or of corn in a heap. The sailor sees the burthen, the built, and the distance of a ship at sea, while she is a great way off. Every man accustomed to writing, distin- guishes his acquaintance by their hand- writing, as he does by their faces. And the painter distinguishes, in the works of his art, the style of all the great masters. In a word, acquired perception is very different in different persons, according to the divers- ity of objects about which they are em- ployed, and the application they bestow in observing them. Perception ought not only to be distin- guished from sensation, but likewise from that knowledge of the objects of sense which is got by reasoning. There is no reasoning in perception, as hath been ob- served. The belief which is implied in it, is the effect of instinct. But there are many things, with regard to sensible ob- jects, which we can infer from what we perceive ; and such conclusions of reason ought to be distinguished from what is merely perceived. When I look at the # In this passage Reid admits Figure and Place (consequently, Extension) to be original perceptions of vision. See above, p. 123, b . note f. — H. moon, I perceive her to be sometimes cir- cular, sometimes horned, and sometimes gibbous. This is simple perception, and is the same in the philosopher and in the clown : but from these various appearances of her enlightened part, I infer that she is really of a spherical figure. This conclu- sion is not obtained by simple perception, but by reasoning. Simple perception has the same relation to the conclusions of rea- son drawn from our perceptions, as the axioms in mathematics have to the pro- positions. I cannot demonstrate that two quantities which are equal to the same quantity, are equal to each other ; neither can I demonstrate that the tree which I perceive, exists. But, by the constitution of my nature, my belief is irresistibly car- ried along by my apprehension of the axiom ; and, by the constitution of my nature, my belief is no less irresistibly car- ried along by my perception of the tree. All reasoning is from principles. The first principles of mathematical reasoning arp mathematical axioms and definitions ; and the first principles of all our reasoning about existences, are our perceptions. The first principles of every kind of reasoning are given us by Nature, and are of equal authority with the faculty of reason itself, which is also the gift of Nature. The con- clusions of reason are all built upon first principles, and can have no other founda- tion. Most justly, therefore, do such prin- ciples disdain to be tried by reason, and laugh at all the artillery of the logician, when it is directed against them. When a long train of reasoning is neces- sary in demonstrating a mathematical pro- position, it is easily distinguished from an axiom ; and they seem to be things of a very different nature. But there are some pro- positions which lie so near to axioms, that it is difficult to say whether they ought to be held as axioms, or demonstrated as pro- positions. The same thing holds with regard to perception, and the conclusions drawn from it. Some of these conclusions follow our perceptions so easily, and are so immediately connected with them, that it is difficult to fix the limit which divides the one from the other. Perception, whether original or acquired, implies no exercise of reason ; and is com- mon to men, children, idiots, and brutes. The more obvious conclusions drawn from our perceptions, by reason, make what we call common understanding ; by which men conduct themselves in the common affairs of life, and by which they are distinguished from idiots. The more remote conclusions which are drawn from our perceptions, by reason, make what we commonly call science in the various parts of nature, whether in agriculture, medicine, mechanics, or in any 186 OF THE HUMAN MIND. part of natural philosophy. When I see a garden in good order, containing a great variety of things of the best kinds, and in the most flourishing condition, I immedi- ately conclude from these signs the skill and industry of the gardener. A farmer, when he rises in the morning, and perceives that the neighbouring brook overflows his field, concludes that a great deal of rain hath fallen in the night. Perceiving his fence broken, and his corn trodden down, he concludes that some of his own or his neighbours' cattle have broke loose. Per- ceiving that his stable-door is broke open, and some of his horses gone, he concludes that a thief has carried them off. He traces the prints of his horses' feet in the soft ground, and by them discovers which road the thief hath taken. These are instances of common understanding, which dwells so near to perception that it is difficult to trace the line which divides the one from the other. In like manner, the science of nature dwells so near to common understanding that we cannot discern where the latter ends and the former begins. I perceive that bodies lighter than water swim in water, and that those which are heavier sink. Hence I conclude, that, if a body remains wherever it is put under water, whether at the top or bottom, it is precisely of the same weight with water. If it will rest only when part of it is above water, it is lighter than water. And the greater the part above water is, compared with the whole, the lighter is the body. If it had no gravity at all, it would make no impression upon the water, but stand wholly above it. Thus, every man, by common understanding, has a rule by which he judges of the specific gravity of bodies which swim in water : and a step or two more leads him into the science of hydro- statics. All that we know of nature, or of exist- ences, may be compared to a tree, which hath its root, trunk, and branches. In this tree of knowledge, perception is the root, common understanding is the trunk, and the sciences are the branches. Section XXI. OF THE PROCESS OF NATURE IN PERCEPTION. Although there is no reasoning in per- ception, yet there are certain means and instruments, which, by the appointment of nature, must intervene between the object and our perception of it ; and, by these, our perceptions are limited and -regulated. First, If the object is not in contact with the organ of sense, there must be some medium which passes between them. Thus, in vision, the rays of light ; in hearing, the vibrations of elastic air; in smelling, the effluvia of the body smelled — must pass from the object to the organ ; otherwise we have no perception. * Secondly, There must be some action or impression upon the organ of sense, either by the immediate applica- tion of the object, or by the medium that goes between them. Thirdly, The nerves which go from the brain to the organ must receive some impression by means of that which was made upon the organ ; and, pro- bably, by means of the nerves, some im- pression must be made upon the brain. Fourthly, The impression made upon the organ, nerves, and brain,' is followed by a sensation. And, last of all, This sensation is followed by the perception of the object. f Thus, our perception of objects is the re- sult of a train of operations ; some of which affect the body only, others affect the mind. We know very little of the nature of some of these operations ; we know not at all how they are connected together, or in what way they contribute to that perception which is the result of the whole ; but, by the laws of our constitution, we perceive objects in this, and iu no other way. There may be other beings who can per- ceive external objects without rays of light, or vibrations of air, or effluvia of bodies — without impressions on bodily organs, or even without sensations ; but we are so framed by the Author of Nature, that, even when we are surrounded by external objects, we may perceive none of them. Our faculty of perceiving an object lies dormant, until it is roused and stimulated by a certain corresponding sensation. Nor is this sens- ation always at hand to perform its office ; for it enters into the mind only in conse- quence of a certain corresponding impres- sion made on the organ of sense by the ob- ject. Let us trace this correspondence of im- pressions, sensations, and perceptions, as far as we can — beginning with that which is first in order, the impression made upon the bodily organ. But, alas ! we know not of what nature these impressions are, far less how they excite sensations in the mind. We know that one body may act upon another by pressure, by percussion, by at- traction, by repulsion, and, probably, in many other ways which we neither know nor have names to express. But in which of these ways objects, when perceived by us, act upon the organs of sense, these organs upon the nerves, and the nerves * The only object of perception is the immediate object. The distant reality— the mediate object, or object simply of Reid and other philosophers — is un- known to the perception of sense, and only reached by reasoning. — H. t That sensation prop r precedes perception pro. per is a false assumption. They are simultaneous elements of the same indivisible energy H. OF SEEING. 18? upon the brain, we know not. Can any man tell me how, in vision, the rays of light act upon the retina, how the retina acts upon the optic nerve, and how the optic nerve acts upon the brain ? No man can. When I feel the pain of the gout in my toe, I know that there is some unusual im- pression made upon that part of my body. But of what kind is it ? Are the small vessels distended with some redundant elastic, or'unelastie fluid? Are the fibres unusually stretched ? Are they torn asunder by force, or gnawed and corroded by some acrid humour ? I can answer none of these questions. All that I feel is pain, which is not an impression upon the body, but upon the mind ; and all that I perceive by this sensation is, that some dis- temper in my toe occasions this pain. But, as I know not the natural temper and tex- ture of my toe when it is at ease, I know as little what change or disorder of its parts occasions this uneasy sensation. In like manner, in every other sensation, there is, without doubt, some impression made upon the organ of sense ; but an impression of which we know not the nature. It is too subtile to be discovered by our senses, and we may make a thousand conjectures with- out coming near the truth. If we under- stood the structure of our organs of sense so minutely as to discover what effects are produced upon them by external objects, this knowledge would contribute nothing to our perception of the object ; for they per- ceive as distinctly who know least about the manner of perception, as the greatest adepts. It is necessary that the impression be made upon our organs, but not that it be known. "Nature carries on this part of the process of perception, without our consciousness or concurrence. But we cannot be unconscious of the next step in this process — the sensation of the mind, which always immediately follows the impression made upon the body. It is essential to a sensation to be felt, and it can be nothing more than we feel it to be. If we can only acquire the habit of attending to our sensations, we may know theih per- fectly. But how are the sensations of the mind produced by impressions upon the body ? Of this we are absolutely iguorant, having no means of knowing how the body acts upon the mind, or the mind upon the body. When we consider the nature and attributes of both, they seem to be so differ- ent, and so unlike, that we can find no handle by which the one may lay hold of the other. There is a deep and a dark gulf between them, which our understanding cannot pass ; and the manner of their correspondence and intercourse is absolutely unknown. Experience teaches us, that certain im- pressions upon the body are constantly fol- lowed by certain sensations of the mind ; and that, on the other hand, certain deter- minations of the mind are constantly fol- lowed by certain motions in the body ; but we see not the chain that ties these things together. Who knows but their connection may be arbitrary, and owing to the will of our Maker ? Perhaps the same sensations might have been connected with other im- pressions, or other bodily organs. Perhaps we might have been so made as to taste with our fingers, to smell with our ears, and to hear by the nose. Perhaps we might have been so made as to have all the sensations and perceptions which we have, without any impression made upon our bodily organs at all. However these things may be, if. Nature had given us nothing more than impressions made upon the body, and sensations in our minds corresponding to them, we should, in that case, have been merely sentient, but not percipient beings. We should never have been able to form a conception of any ex- ternal object, far less a belief of its exist- ence. Our sensations have no resemblance to external objects ; nor can we discover, by our reason, any necessary connection between the existence of the former, and that of the latter. We might, perhaps, have been made of such a constitution as to have our present perceptions connected with other sensations. We might, perhaps, have had the percep- tion of external objects, without either im- pressions upon the organs of sense, or sens- ations. Or, lastly, The perceptions we have, might have been immediately connected with the impressions upon our organs, with- out any intervention of sensations. This last seems really to be the case in one in- stance — to wit, in our perception of the visible figure of bodies, as was observed in the eighth section of this chapter. The process of Nature, in perception by the'senses, may, therefore, be conceived as a kind of drama, wherein some things are per- formed behind the scenes, others are repre- sented to the mind in different scenes, one succeeding another. The impression made by the object upon the organ, either by im- mediate contact or by some intervening medium, as well as the impression made upon the nerves and brain, is performed behind the scenes, and the mind sees nothing of it. But every such impression, by the laws of the drama, is followed by a sensa- tion, which is the first scene exhibited to the mind ; and this scene is quickly suc- ceeded* by another, which is the percep- tion of the object. In this drama, Nature is the actor, we are the spectators. We know nothing of • See the preceding note.— H. 188 OF THE HUMAN MIND. the machinery by means of which every different impression upon the organ, nerves, and brain, exhibits its corresponding sens- ation; or of the machinery by means of which each sensation exhibits its corre- sponding perception. We are inspired with the sensation, and we are inspired with the corresponding perception, by means un- known.* And, because the mind passes immediately from the sensation to that con- ception and belief of the object which we have in perception, in the same manner as it passes from signs to the things signified by them, we have, therefore, called our sensations signs of external objects ; finding no word more proper to express the func- tion which Nature hath assigned them in perception, and the relation which they bear to their corresponding objects. There is no necessity of a resemblance between the sign and the thing signified ; and indeed no sensation can resemble any external object. But there are two things necessary to our knowing things by means of signs. First, That a real connection between the sign and thing signified be established, either by the course of nature, or by the will and appointment of men. When they are connected by the course of nature, it is a natural sign ; when by hu- man appointment, it is an artificial sign. Thus, smoke is a natural sign of fire ; cer- tain features are natural signs of anger : but our words, whether expressed by arti- culate sounds or by writing, are artificial signs of our thoughts and purposes. Another requisite to our knowing things by signs is, that the appearance of the sign to the mind, be followed by the conception and belief of the thing signified. Without this, the sign isnot understood orinterpreted; and, therefore, is no sign to us, however fit in its own nature for that purpose. Now, there are three ways in which the mind passes from the appearance of a natu- ral sign to the conception and belief of the thing signified — by original principles of our constitution, by custom, and by reason- ing. Our original perceptions are got in the first of these ways, our acquired percep- tions in the second, and all that reason dis- covers of the course of nature, in the third. In the first of these ways, Nature, by means of the sensations of touch, informs us of the hardness and softness of bodies ; of their extension, figure, and motion ; and of that space in which they move and are placed as hath been already explained in the fifth chapter of this inquiry. And, in the second of these ways, she informs us, by means of onr eyes, of almost all the same things • On perception as a revelation — "a miraculous revelatio»"_see Jacobi's 'vpavid Hume."— H. which originally we could perceive only by touch. In order, therefore, to understand more particularly how we learn to perceive so many things by the eye, which originally could be perceived only by touch, it will be proper, First, To point out the signs by which those things are exhibited to the eye, and their connection with the things signi- fied by them ; and, Secondly, To consider how the experience of this connection pro- duces that habit by which the mind, with- out any reasoning or reflection, passes from the sign to the conception and belief of the thing signified. Of all the acquired perceptions which we have by sight, the most remarkable is the perception of the distance of objects from the eye ; we shall, therefore, particularly consider the signs by which this perception is exhibited, and only make some general remarks with regard to the signs which are used in other acquired perceptions. Section XXII. OP THE SIGNS BY WHICH WE LEARN TO PERCEIVE DISTANCE FROM THE EYE. It was before observed in general, that the original perceptions of sight are signs which serve to introduce those that are acquired ; but this is not to be understood as if no other signs were employed, for that purpose. There are several motions of the eyes, which, in order to distinct vision, must be varied, according as the object is more or less distant ; and such motions be- ing by habit connected with the correspond- ing distances of the object, become signs of those distances.* These motions were at first voluntary and unconfined ; hut, as the intention of nature was to produce perfect and distinct vision by their means, we soon learn by experience to regulate them accord- ing to that intention only, without the least reflection. A ship requires a different trim for every variation of the direction and strength of the wind ; and, if we may be allowed to borrow that word, the eyes require a differ- ent trim for every degree of light, and for every variation of the distance of the object, while it is within certain limits. The eyes are trimmed for a particular object, by con- tracting certain muscles and relaxing others; as the ship is trimmed for a particular wind by drawing certain ropes and slackening others. The sailor learns the trim of his ship, as we learn the trim of our eyes, by experience. A ship, although the noblest machine that human art can boast, is far • See above, p. 182, note ».— H. OF SEEING. 189 inferior to the eye in this respect, that it requires art and ingenuity to navigate her ; and a sailor must know what ropes he must pull, and what he must slacken, to fit her to a particular wind ; but with such superior wisdom is the fabric of the eye, and the principles of its motion contrived, that it requires no art nor ingenuity to see by it. Even that part of vision which is got by experience, is attained by idiots. We need not know what muscles we are to contract, and what we are to relax, in order to fit the eye to a particular distance of the object. But, although we are not conscious of the motions we perform, in order to fit the eyes to the distance of the object, we are aon- scious of the effort employed in producing these motions ; and probably have some sensation which accompanies them, to which we give as little attention as to other sensa- tions. And thus, an effort consciously ex- erted, or a sensation consequent upon that effort, comes to be conjoined with the dis- tance of the object which gave occasion to it, and by this conjunction becomes a sign of that distance. Some instances of this will appear in considering the means or signs by which we learn to see the distance of objects from the eye. In the enumera- tion of these, we agree with Dr Porterfield, notwithstanding that distance from the eye, in his opinion, is perceived originally, but, in our opinion, by experience only. In general, when a near object affects the eye in one manner, and the same object, placed at a greater distance, affects it in a different manner, these various affections of the eye become signs of the correspond- ing distances. The means of perceiving distance by the eye will therefore be ex- plained by shewing in what various ways objects affect the eye differently, according to their proximity or distance. 1. It is well known, that, to see objects distinctly at various distances, the form of the eye must undergo some change : and nature hath given us the power of adapting it to near objects, by the contraction of certain muscles, and to distant objects by the contraction of other muscles. As to the manner in which this is done, and the muscular parts employed, anatomists do not altogether agree. The ingenious Dr Jurin, in his excellent essay on distinct and indis- " tinct vision, seems to have given the most probable account of this matter ; and to him I refer the reader.* But, whatever be the manner in which this change of- the form of the eye is ef- fected, it is certain that young people have commonly the power of adapting their eyes * The mole in which the eye-is accommodated to its various perceptions, is a subject which has obtained much attention from the more recent physiologists. — a. to all distances of the object, from six or seven inches, to fifteen or sixteen feet ; so as to have perfect and distinct vision at any distance within these limits. From this it follows, that the effort we consciously em- ploy to adapt the eye to any particular dis- tance of objects within these limits, will be connected and associated with that dis- tance, and will become a sign of it. When the object is removed beyond the farthest limit of distinct vision, it will be seen in- distinctly ; but, more or less so, according as its distance is greater or less ; so that the degrees of indistinctness of the object may become the signs of distances consi- derably beyond the farthest limit of distinct vision. If we had no other mean but this, of per- ceiving distance of visible objects, the most distant would not appear to be above twenty or thirty feet from the eye, and the tops of houses and trees would seem to touch the clouds ; for, in that case, the signs of all greater distances being the same, they have the same signification, and give the same perception of distance. But it is of more importance to observe, that, because the nearest limit of distinct vision in the time of youth, when we learn to perceive distance by the eye, is about six or seven inches, no object seen dis- tinctly ever appears to be nearer than six or seven inches from the eye. We can, by art, make a small object appear dis- tinct, when it is in reality not above half an inch from the eye ; either by using a single microscope, or by looking through a small pin-hole in a card. When, by either of these means, an object is made to appear distinct, however small its dis- tance is in reality, it seems to be removed at least to the distance of six or seven inches— that is, within the limits of distinct vision. This observation is the more important, because it affords the only reason we can give why an object is magnified either by a single microscope, or by being seen through a pin-hole ; and the only mean by which we can ascertain the degree in which the object will be magnified by either. Thus, if the object is really half an inch distant from the eye, and appears to be seven inches distant, its diameter will seem to be enlarged in the same proportion as its distance that is, fourteen times. 2. In order to direct both eyes to an object, the optic axes must have a greater or less inclination, according as the object is nearer or more distant. And, although we are not conscious of this inclination, yet we are conscious of the effort employed in it. By this mean we perceive small distances more accurately than we could do by the conformation of the eye only 190 OF THE HUMAN MIND. And, therefore, we find, that those who have lost the sight of one eye are apt, even within arm's-length, to make mistakes in the distance of objects, which are easily avoided by those who see with both eyes. Such mistakes are often discovered in snuff- ing a candle, in threading a needle, or in filling a tea-cup.* When a picture is seen with both eyes, and at no great distance, the representation appears not so natural as when it is seen only with one. The intention of painting being to deceive the eye, and to make things appear at different distances which in reality are upon the same piece of canvass, this deception is not so easily put upon both eyes as upon one ; because we perceive the distance of visible objects more exactly and determinately with two eyes than with one. If the shading and relief be executed in the best manner, the picture may have almost the same appearance to one eye as the obj ects themselves would have ; but it cannot have the same appearance to both. This is not the fault of the artist, but an unavoid- able imperfection in the art. And it is owing to what we just now observed, that the perception we have of the distance of objects by one eye is more uncertain, and more liable to deception, than that which we have by both. The great impediment, and I think the only invincible impediment, to that agree- able deception of the eye which the painter aims at, is the perception which we have of the distance of visible objects from the eye, partly by means of the conformation of the eye, but chiefly by means of the inclination of the optic axes. If this perception could be removed, I see no reason why a picture might not be made so perfect as to deceive the eye in reality, and to be mistaken for the original object. Therefore, in order to judge of the merit of a picture, we ought, as much as possible, to exclude these two means of perceiving the distance of the several parts of it. In order to remove this perception of dis- tance, the connoisseurs in painting use a method which is very proper. They look at the picture with one eye, through a tube which excludes the view of all other objects. By this method, the principal mean whereby we perceive the distance of the object — to wit, the inclination of the optic axes — is en- tirely excluded. I would humbly propose, as an improvement of this method of view- ing pictures, that the aperture of the tube next to the eye should be very small. If it is as small as a pin-hole, so much the better, providing there be light enough to see the picture clearly. The reason of this proposal * The same remark i3 made by many optical wri- ters, old and new. — H, is, that, when we look at an object through a small aperture, it will be seen distinctly, whether the conformation of the eye be adapted to its distance or not ; and we have no mean left to judge of the distance, but the light and colouring, which are in the painter's power. If, therefore, the artist performs his part properly, the picture will by this method affect the eye in the same manner that the object represented would do ; which is the perfection of this art. Although this second mean of perceiving the distance of visible objects be more de- terminate and exact than the first, yet it hath its limits, beyond which it can be 01 no use. For when the optic axes directed to an object are so nearly parallel that, in directing them to an object yet more distant, we are not conscious of any new effort, nor have any different sensation, there our per- ception of distance stops ; and, as all more distant objects affect the eye in the same manner, we perceive them to be at the same distance. This is the reason why the sun, moon, planets, and fixed stars, when seen not near the horizon, appear to be all at the same' distance, as if they touched the concave surface of a great sphere. The surface of this celestial sphere is at that distance beyond which all objects affect the eye in the same manner. Why thif celestial vault appears more distant towards the horizon, than towards the zenith, will afterwards appear. 3. The colours of objects, according as they are more distant, become more faint and languid, and are tinged more with the azure of the intervening atmosphere : to this we may add, that their minute parts become more indistinct, and their outline less accurately defined. It is by these means chiefly, that painters can represent objects at very different distances, upon the same canvass. And the diminution of the magnitude of an object would not have the effect of making it appear to be at a great distance, without this degradation of colour, and indistinctness of the outline, and of the minute parts. If a painter should make a human figure ten times less than other human figures that are in the same piece, having the colours as bright, and the out- line and minute parts as accurately defined, it would not have the appearance of a man at a great distance, hut of a pigmy or Lilli- putian. When an object hath a known variety of colours, its distance is more clearly indi- cated by the gradual dilution of the colours into one another, than when it is of one uniform colour. In the steeple which stands before me at a small distance, the joinings of the stones are clearly percepti- ble ; the grey colour of the stone, and the white cement are distinctly limited : when OF SEEING. 191 I see it at a greater distance, the joinings of the stones are less distinct, and the colours of the stone and of the cement begin to dilute into one another : at a distance still greater, the joinings disappear altogether, and the variety of colour vanishes. In an apple-tree which stands at the dis- tance of about twelve feet, covered with flowers, I can perceive the figure and the colour of the leaves and petals ; pieces of branches, some larger, others smaller, peep- ing through the intervals of the leaves — some of them enlightened by the sun's rays, others shaded ; and some openings of the sky are perceived through the whole. When I gradually remove from this tree, the ap- pearance, even as to colour, changes every minute. First, the smaller parts, then the larger, are gradually confounded and mixed. The colours of leaves, petals, branches, and sky, are gradually diluted into each other, and the colour of the whole becomes more and more uniform. This change of appearance, corresponding to the several dis- tances, marks the distance more exactly than if the whole object had been of one colour. Dr Smith, in his " Optics," gives us a very curious observation made by Bishop Berke- ley, in his travels through Italy and Sicily. He observed, That, in those countries, cities and palaces seen at a great distance appeared nearer to him by several miles than they really were : and he very judi- ciously imputed it to this cause, That the purity of the Italian and Sicilian air, gave to very distant objects that degree of brightness and distinctness which, in the grosser air of his own country, was to be seen only in those that are near. The purity of the Italian air hath been assigned as the reason why the Italian painters commonly give a more lively colour to the sky than the Flemish. Ought they not, for the same reason, to give less degrad- ation of the colours, and less indistinct- ness of the minute parts, in the representa- tion of very distant objects ? It is very certain that, as in air uncom- monly pure, we are apt to think visible objects nearer and less than' they really are, so, in air uncommonly foggy, we are apt to think them more distant and larger than the truth. Walking by the sea-side in a thick fog, I see an object which seems to me to be a man on horseback, and at the distance of about half a mile. My com- panion, who has better eyes, or is more accustomed to see such objects in such cir- cumstances, assures me that it is a sea- gull, and not a man on horseback. Upon a second view, I immediately assent to his opinion ; and now it appears to me to be a sea -gull, and at the distance only of seventy or eighty yards. The mistake made on this occasion, and the correction of it, are both so sudden, that we are at a loss whether to call them by the name of judgment, or by that of simple perception. It is not worth while to dispute about names 5 but it is evident that my belief, both first and last, was produced rather by signs than by arguments, and that the mind proceeded to the conclusion in both cases by habit, and not by ratiocination. And the process of the mind seems to have been this — First, Not knowing, or not minding, the effect of a foggy air on the vis- ible appearance of objects, the object seems to me to have that degradation of colour, and that indistinctness of the outline, which objects have at the distance of half a mile ; therefore, from the visible appearance as a sign, I immediately proceed to the belief that the object is half a mile distant. Then, this distance, together with the vis- ible magnitude, signify to me the real magnitude, which, supposing the distance to be half a mile, must be equal to that of a man on horseback ; and the figure, considering the indistinctness of the outline, agrees with that of a man on horseback. Thus the deception is brought about. But when I am assured that it is a sea-gull, the real magnitude of a sea-gull, together with the visible magnitude presented to the eye, immediately suggest the distance, which, in this case, cannot be above seventy or eighty yards : the indistinctness of the figure likewise suggests the fogginess of the air as its cause ; and now the whole chain of signs, and things signified, seems stronger and better connected than it was before ; the half mile vanishes to eighty yards; the man on horseback dwindles to a sea- gull ; I get a new perception, and wonder how I got the former, or what is become of it ; for it is now so entirely gone, that I cannot recover it. It ought to be observed that, in order to produce such deceptions from the clearness or fogginess of the air, it must be uncom- monly clear or uncommonly foggy ; for we learn, from experience, to make allowance for that variety of constitutions of the air which we have been accustomed to observe, and of which we are aware. Bishop Berkeley therefore committed a mistake, when he attributed the large appearance of the horizontal moon to the faintness of her light, occasioned by its passing through a larger tract of atmosphere :* for we are so much accustomed to see the moon in all degrees of faintness and brightness, from the greatest to the least, that we learn to make allowance for it ; and do not imagine her magnitude increased by the faintness of her appearance. Besides, it is certain that the horizontal moon seen through a tube * Thia explanation was not original to Berkeley. — II 192 OF THE HUMAN MIND. which cuts off the view of the interjacent ground, and of all terrestrial objects, loses all that unusual appearance of magnitude. 4. We frequently perceive the distance of objects, by means of intervening or con- tiguous objects, whose distance or magni- tude is otherwise known. When I perceive certain fields or tracts of ground to he be- tween me and an object, it is evident that these may become signs of its distance. And although we have no particular in- formation of the dimensions of such fields or tracts, yet their similitude to others which we know, suggests their dimensions. We are so much accustomed to measure with our eye the ground which we travel, and to compare the judgments of distances formed by sight, with our experience or in- formation, that we learn by degrees, in this way, to form a more accurate judgment of the distance of terrestrial objects, than we could do by any of the means before men- tioned. An object placed upon the top of a high building, appears much less than when placed upon the ground, at the same distance. When it stands upon the ground, the intervening tract of ground serves as a sign of its distance ; and the distance, to- gether with the visible magnitude, serves ;is a sign of its real magnitude. But when the object is placed on high, this sign of its distance is taken away : the remaining signs lead us to place it at a less distance ; and this less distance, together with the visible magnitude, becomes a sign of a less real magnitude. The two first means we have mentioned, would never of themselves make a visible object appear above a hundred and fifty, or two hundred feet, distant ; because, be- yond that there is no sensible change, either of the conformation of the eyes, or of the inclination of their axes. The third mean is but a vague and undeterminate sign, when applied to distances above two or three hundred feet, unless we know the real colour and figure of the object ; and the fifth mean, to be afterwards mentioned, can only be applied to objects which are fami- liar, or whose real magnitude is known. Hence it follows, that, when unknown ob- jects, upon or near the surface of the earth, are perceived to be at the distance of some miles, it is always by this fourth mean that we are led to that conclusion. Dr Smith hath observed, very justly, that the known distance of the terrestrial objects which terminate our view, makes that part of the Bky which is towards the horizon uppear more distant than that which is to- wards the zenith. Hence it comes to pass, that the apparent figure of the sky is not that of a hemisphere, but rather a less seg- ment of a sphere. And, hence, likewise, it comes to pass, that the diameter of the sun or moon, or the distance between two fixed stars, seen contiguous to a hill, or to any distant terrestrial object, appears much greater than when no such object strikes the eye at the same time. These observations have been sufficiently explained and confirmed by Dr Smith. I beg leave to add, that, when the visible horizon is terminated by very distant ob- jects, the celestial vault seems to be en- larged in all its dimensions. When I view it from a confined street or lane, it bears some proportion to the buildings that sur- round me ; but, when I view it from a large plain, terminated on all hands by hills which rise one above another to the distance of twenty miles from the eye, methmks I see a new heaven, whose magnificence declares the greatness of its Author, and puts every human edifice out of countenance ; for now the lofty spires and the gorgeous palaces shrink into nothing before it, and bear no more proportion to the celestial dome than their makers bear to its Maker. 5. There remains another mean by which we perceive the distance of visible objects — and that is, the diminution of their visible or apparent magnitude. By experience, I know what figure a man, or any other known object, makes to my eye at the distance of ten feet — I perceive the gradual and pro- portional diminution of this visible figure, at the distance of twenty, forty, a hundred feet, and at greater distances, until it vanish altogether. Hence a certain visible magni- tude of a known object becomes the sign of a certain determinate distance, and carries along with it the conception and belief of that distance. In this process of the mind, the sign is not a sensation ; it is an original percep- tion. We perceive the visible figure and visible magnitude of the object, by the ori- ginal powers of vision ; but the visible figure is used only as a sign of the real figure, and the visible magnitude is used only as a sign either of the distance, or of the real magni- tude, of the object ; and, therefore, these original perceptions, like other mere signs, pass through the mind without any atten- tion or reflection. This last mean of perceiving the dis- tance of known objects, serves to explain some very remarkable phenomena in op- tics, which would otherwise appear very mysterious. When we view objects of known dimensions through optical glasses, there is no other mean left of determining their distance, but this fifth. Hence it follows, that known objects seen through glasses, must seem to be brought nearer, in proportion to the magnifying power of the glass, or to be removed to a greater distance, in proportion to the diminishing power of the glass. OF SEEING. 193 If a man who had never before seen ob- jects through a telescope, were told that the telescope, which he is about to use, mag- nifies the diameter of the object ten times ; when he looks through this telescope at a man six feet high, what would he expect to see ? Surely he would very naturally expect to see a giant sixty feet high. But he sees no such thing. The man appears no more than six feet high, and conse- quently no bigger than he really is ; but he appears ten times nearer than he is. The telescope indeed magnifies the image of this man upon the retina ten times in dia- meter, and must, therefore, magnify his visible figure in the same proportion ; and, as we have been accustomed to see him of this visible magnitude when he was ten times nearer than he is presently,* and in no other case, this visible magnitude, there- fore, suggests the conception and belief of that distance of the object with which it hath been always connected. We have been accustomed to conceive this amplifi- cation of the visible figure of a known ob- ject, only as the effect or sign of its being brought nearer : and we have annexed a certain determinate distance to every de- gree of visible magnitude of the object ; and, therefore, any particular degree of vi- sible magnitude, whether seen by the naked eye or by glasses, brings along with it the conception and belief of the distance which corresponds to it. This is the reason why a telescope seems not to magnify known objects, but to bring them nearer to the eye. When we look through a pin-hole, or a single microscope, at an object which is half an inch from the eye, the picture of the object upon the retina is not enlarged, but only rendered distinct ; neither is the visible figure enlarged : yet the object ap- pears to the eye twelve or fourteen times more distant, and as many times larger in diameter, than it really is. Such a tele- scope as we have mentioned amplifies the image on the retina, and the visible figure of the object, ten times in diameter, and yet makes it seem no bigger, but only ten times nearer. These appearances had been long observed by the writers on optics ; they tor- tured their invention to find the causes of them from optical principles ; but in vain : they must be resolved into habits of percep- tion, which are acquired by custom, but are apt to be mistaken for original percep- tions. The Bishop of Cloyne first furnished the world with the proper key for opening up these mysterious appearances ; but he made considerable mistakes in the applica- tion of it. Dr Smith, in his elaborate and ju- dicious treatise of " Optics," hath applied it * Sec note * p. 96, a.— H. to the apparent distance of objects seen with glasses, and to the apparent figure of the heavens, with such happy success, that there can be no more doubt about the causes of these phenomena. Section XXIII. OF THE SIGNS USED IN OTHER ACQUIRED PER- CEPTIONS. The distance of objects from the eye is the most important lesson in vision. Many others are easily learned in consequence of it. The distance of the object, joined with its visible magnitude, is a sign of its real magnitude : and the distance of the several parts of an object, joined with its visible figure, becomes a sign of its real figure. Thus, when I look at a globe which stands before me, by the original powers of sight I perceive only something of a circular form, variously coloured. The visible figure hath no distance from the eye, no convexity, nor hath it three dimensions ; even its length and breadth are incapable of being mea- sured by inches, feet, or other linear mea- sures. But, when I have learned to per- ceive the distance of every part of this object from the eye, this perception gives it convexity, and a spherical figure ; and adds a third dimension to that which had but two before. The distance of the whole object makes me likewise perceive the real magnitude ; for, being accustomed to ob- serve how an inch or a foot of length affects the eye at that distance, I plainly perceive by my eye the linear dimensions of the globe, and can affirm with certainty that its diameter is about one foot and three inches. It was shewn in the 7th section of this chapter that the visible figure of a body may, by mathematical reasoning, be inferred from its real figure, distance, and position, with regard to the eye: in like manner, we may, by mathematical reason- ing, from the visible figure, together with the distance of the several parts of it from the eye, infer the real figure and position. But this last inference is not commonly made by mathematical reasoning, nor, in- deed, by reasoning of any kind, but by cus- tom. The original appearance which the colour of an object makes to the eye, is a sensa- tion for which we. have no name, because it is used merely as a sign, and is never made an object of attention in common life : but this appearance, according to the different circumstances, signifies various things. If a piece of cloth, of one uniform colour, is laid so that part of it is in the sun, and part in the shade, the appearance of colour, in 194 OF THE HUMAN MIND. these different parts, is very different : yet we perceive the colour to be the same ; we interpret the variety of appearance as a sign of light and shade, and not as a sign of real difference in colour. But, if the eye could he so far deceived as not to per- ceive the difference of light in the two parts of the cloth, we should, in that case, interpret the variety of appearance to signify a variety of colour in the parts of the cloth. Again, if we suppose a piece of cloth placed as before, but having the shaded part so much brighter in the colour that it gives the same appearance to the eye as the more enlightened part, the sameness of appear- ance will here be interpreted to signify a variety of colour, because we shall make allowance for the effect of light and shade. When the real colour of an object is known, the appearance of it indicates, in some circumstances, the degree of light or shade ; in others, the colour of the cir- cumambient bodies, whose rays are reflected by it ; and, in other circumstances, it indi- cates the distance or proximity of the ob- ject — as was observed in the last section ; and by means of these, many other things are suggested to the mind. Thus, an un- usual appearance in the colour of familiar objects may be the diagnostic of a disease in the spectator. The appearance of things in myroom may indicate sunshine or cloudy weather, the earth covered with snow or blackened with rain. It hath been ob- served, that the colour of the sky, in a piece of painting, may indicate the country of the painter, because the Italian sky is really of a different colour from the Flemish. It was already observed, that the original and acquired perceptions which we have by our senses, are the language of nature to man, which, in many respects, hath a great affinity to human languages. The instances which we have given of acquired perceptions, suggest this affinity — that, as, in human languages, ambiguities are often found, so this language of nature in our ac- quired perceptions is not exempted from them. .We have seen, in vision particu- larly, that the same appearance to the eye, may, in different circumstances, indicate different things. Therefore, when the cir- cumstances are unknown upon which the interpretation of the signs depends, their meaning must be ambiguous ; and when the circumstances are mistaken, the meaning of the signs must also be mistaken. This is the case in all the phsenomena which we call fallacies of the senses ; and particularly in those which are called fallacies in vision. The appearance of things to the eye always corresponds to the fixed laws of Nature ; therefore, if we speak properly, there is no fallacy in the senses. Nature always speaketh the same language, and useth the same signs in the same cir- cumstances ; but we sometimes mistake the meaning of the signs, either through ignorance of the laws of Nature, or through ignorance of the circumstances which attend the signs.* To a man unacquainted with the prin- ciples of optics, almost every experiment that is made with the prism, with the magic lanthorn, with the telescope, with the mi- croscope, seems to produce some fallacy in vision. Even the appearance of a common mirror, to one altogether unacquainted with the effects of it, would seem most remark- ably fallacious. For how can a man be more imposed upon, than in seeing that before him which is really behind him ? How can he be more imposed upon, than in being made to see himself several yards removed from himself? Yet children, even before they can speak their mother- tongue, learn not to be deceived by these appearances. These, as well as all the other surprising appearances produced by optical glasses, are a part of the visual lan- guage, and, to those who understand the laws of Nature concerning light and colours, are in nowise fallacious, but have a dis- tinct and true meaning. Section XXIV. OF THE ANALOGY BETWEEN PERCEPTION AND THE CREDIT WE GIVE TO HUMAN TESTIMONY. \ The objects of human knowledge are in- numerable ; but the channels by which it is conveyed to the mind are few. Among these, the perception of external things by our senses, and the informations which we receive upon human testimony, are not the least considerable ; and so remarkable is the analogy between these two, and the analogy between the principles of the mind which are subservient to the one and those which are subservient to the other, that, without further apology, we shall consider them together. In the testimony of Nature given by the senses, as well as in human testimony given by language, things are signified to us by signs : and in one as well as the other, the mind, either by original principles or by custom, passes from the sign to the concep- tion and belief of the things signified. We have distinguished our perceptions • This is Ihe doctrine of Aristotle ; who holds that the senses never deceive us in relation to their proper objects H. t Compare Mr Stewart's " Elements," vol. I., ch. ii., 5 *, p. 247. Second edition. Campbell "On Miracles," Part 1,5 1. Smith's •• Theory ol Moral Sentiment," vol II., p. 383. Sixth edition — H. OF SEEING. 19J into original and acquired ; and language, into natural and artificial. Between acquired perception and artificial language, there is a great analogy ; but still a greater between original perception and natural The signs in original perception are sens- ations, of which Nature hath given us a great variety, suited to the variety of the things signified by them. Nature hath established a real connection between the signs and the things signified; andNature hath also taught us the interpretation of the signs — so that, previous to experience, the sign suggests the thing signified, and create the belief of it. The signs in natural language are features of the face, gestures of the body, and modu- lations of the voice ; the variety of which is suited to the variety of the things signified by them. Nature hath established a, real connection between these signs, and the thoughts and dispositions of the mind which are signified by them ; and Nature hath taught us the interpretation of these signs ; so that, previous to experience, the signs suggest the thing signified, and create the belief of it. A man in company, without doing good or evil, without uttering an articulate sound, may behave himself gracefully, civilly, politely ; or, on the contrary, meanly, rudely, and impertinently. We see the dispositions of his mind by their natural signs in his countenance and behaviour, in the same manner as we perceive the figure and other qualities of bodies by the sensa- tions which nature hath connected with them. The signs in the natural language of the human countenance and behaviour, as well as the signs in our original perceptions, have the same signification in all climates and in all nations ; and the skill of inter- preting them is not acquired, but innate. In acquired perception, the signs are either sensations, or things which we per- ceive by means of sensations. The con- nection between the sign and the thing sig- nified, is established by nature; and we discover this connection by experience; but not without the aid of our original per- ceptions, or of those which we have already acquired. After this connection is dis- covered, the sign, in like manner as in original perception, always suggests the things signified, and creates the belief of it. In artificial language, the signs are arti- culate sounds, whose connection with the things signified by them, is established by the will of men; and, in learning our mother tongue, we discover this connection by experience ; but not without the aid of natural language, or of what we had before attained of artificial language. And, after this connection is discovered, the sign, as in natural language, always suggests the thing signified, and creates the belief of it. Our original perceptions are few, com- pared with the acquired ; but, without the former, we could not possibly attain the latter. In like manner, natural language is scanty, compared with artificial ; but, without the former, we could not possibly attain the latter. Our original perceptions, as well as the natural language of human features and gestures, must be resolved into particular principles of the human constitution. Thus, it is by one particular principle of our con- stitution that certain features express anger ; and, by another particular principle, that certain features express benevolence. It is, in like manner, by one particular principle of our constitution that a certain sensation signifies hardness in the body which I handle; and it is by another particular principle that a certain sensation signifies motion in that body. But our acquired perceptions, and the information we receive by means of arti- ficial language, must be resolved into gene- ral principles of the human constitution. When a painter perceives that this picture is the work of Raphael, that the work of Titian ; a jeweller, that this is a true dia- mond, that a counterfeit ; a sailor, that this is a ship of five hundred ton, that of four hundred; these different acquired percep- tions are produced by the same general principles of the human mind, which have a different operation in the same person according as they are variously applied, and in different persons according to the divers- ity of their education and manner of life. In like manner, when certain articulate sounds convey to my mind the knowledge of the battle of Pharsalia, and others, the knowledge of the battle of Poltowa — when a Frenchman and an Englishman receive the same information by different articulate sounds — the signs used in these different cases, produce the knowledge and belief of the things signified, by means of the same general principles of the human constitu- tion. Now, if we compare the general prin- ciples of' our constitution, which fit us for receiving information from our fellow-crea- tures by language, with the general prin- ciples which fit us for acquiring the per- ception of things by our senses, we shall find them to be very similar in their nature and manner of operation. When we begin to learn our mother- tongue, we perceive, by the help of natural language, that they who speak to us use certain sounds to express certain things ; we imitate the same sounds when we would o 2 196 OF THE HUMAN MIND. express the same things ; and find that we are understood. But here a difficulty occurs which merits our attention, because the solution of it leads to some original principles of the hu- man mind, which are of great importance, and of very extensive influence. We know by experience that men have used such words to express such things ; but all ex- perience is of the past, and can, of itself, give no notion or belief of what is future. How come we, then, to believe, and to rely upon it with assurance, that men, who have it in their power to do otherwise, will con- tinue to use the same words when they think the same things ? Whence comes this knowledge and belief — this foresight, we ought rather to call it — of the future and voluntary actions of our fellow-creatures ? Have they promised that they will never impose upon us by equivocation or falsehood ? No, they have not. And, if they had, this would not solve the difficulty; for such promise must be expressed by words or by other signs ; and, before we can rely upon it, we must be assured that they put the usual meaning upon the signs which express that promise. No man of common sense ever thought of taking a man's own word for his honesty ; and it is evident that we take his veracity for granted when we lay any stress upon his word or promise. I might add, that this reliance upon the de- clarations and testimony of men is found in children long before they know what a promise is. There is, therefore, in the human mind an early anticipation, neither derived from experience, nor from reason, nor from any compact or promise, that our fellow-crea- tures will use the same signs in language, when they have the same sentiments. This is, in reality, a kind of prescience of human actions ; and it seems to me to be an original principle of the human con- stitution, without which we should be in- capable of language, and consequently in- capable of instruction. The wise and beneficent Author of Na- ture, who intended that we should be social creatures, and that we should receive the greatest and most important part of our knowledge by the information of others, hath, for these purposes, implanted in our natures two principles that tally with each other. The first of these principles is, a pro- pensity to speak truth, and to use the signs of language so as to convey our real sen- timents. This principle has a powerful operation, even in the greatest liars ; for where they lie once, they speak truth a hundred times. Truth is.always uppermost, and is the natural issue of the mind. It requires no art or training, no inducement or temptation, but only that we yield to n natural impulse. Lying, on the contrary, is doing violence to our nature ; and is never practised, even by the worst men, without some temptation. Speaking truth is like using our natural food, which we would do from appetite, although it an- swered no end ; but lying is like taking physic, which is nauseous to the taste, and which no man takes but for some end which he cannot otherwise attain. If it should be objected, That men may be influenced by moral or political consider- ations to speak truth, and, therefore, that their doing so is no proof of such an origi- nal principle as we have mentioned — I answer, First, That moral or political con- siderations can have no influence until we arrive at years of understanding and reflec- tion ; and it is certain, from experience, that children keep to truth invariably, be- fore they are capable of being influenced by such considerations. Secondly, When we are influenced by moral or political con- siderations, we must be conscious of that influence, and capable of perceiving it upon reflection. Now, when I reflect upon my actions most attentively, I am not conscious that, in speaking truth, I am influenced on ordinary occasions by any motive, moral or political. I find that truth is always at the door of my lips, and goes forth sponta- neously, if not held back. It requires neither good nor bad intention to bring it forth, but only that I be artless andunde- signing. There may indeed be temptations to falsehood, which would be too strong for the natural principle of veracity, unaided by principles of honour or virtue; but where there is no such temptation, we speak truth by instinct — and this instinct is the principle I have been explaining. By this instinct, a real connection is formed between our words and our thoughts, and thereby the former become fit to be signs of the latter, which they could not otherwise be. And although this connec- tion is broken in every Instance of lying and equivocation, yet these instances being comparatively few, the authority of human testimony is only weakened by them, but not destroyed. Another original principle implanted in us by the Supreme Being, is a disposition to confide in the veracity of others, and to believe what they tell us. This is the counterpart to the former ; and, as that maybe called the principle of veracity, we shall, for want of a more proper name, call this the prinoiple of credulity. It is un- limited in children, until they meet with instances of deceit and falsehood; and it retains a very considerable degree of strength through life. If Nature had left the mind of the speaker OF SEEING. 197 in aquitibrio, without any inclination to the side of truth more than to that of false- hood, children would lie as often as they speak truth, until reason was so far ripened as to suggest the imprudence of lying, or conscience, as to suggest its immorality. And if Nature had left the mind of the hearer in aquilibrio, without any inclina- tion to the side of belief more than to that of disbelief, we should take no man's word until we had positive evidence that he spoke truth. His testimony would, in this case, have no more authority than his dreams ; which may be true or false, but no man is disposed to believe them, on this account, that they were dreamed. It is evident that, in the matter of testimony, the balance of human judgment is by nature inclined to the side of belief ; and turns to that side of itself, when there is nothing put into the opposite scale. If it was not so, no proposition that is uttered in dis- course would be believed, until it was examined and tried by reason ; and most men would be unable to find reasons for believing the thousandth part of what is told them. Such distrust and incredulity would deprive us of the greatest benefits of society, and place us in a worse condition than that of savages. Children, on this supposition, would be absolutely incredulous, and, therefore, ab- solutely incapable of instruction : those who had little knowledge of human life, and of the manners and characters of men, would be in the next degree incredulous : and the most credulous men would be those of greatest experience, and of the deepest penetration ; because, in many cases, they would be able to find good reasons for believing testimony, which the weak and the ignorant could not discover. In a word, if credulity were the effect of reasoning and experience, it must grow up and gather strength, in the same proportion as reason and experience do. But, if it is the gift of Nature, it will be strongest in childhood, and limited and restrained by experience ; and the most superficial view of human life shews, that the last is really the case, and not the first. * It is the intention of Nature, that we should be carried in arms before we are able to walk upon our legs ; and it is likewise the intention of Nature, that our belief should be guided by the authority and rea- son of others, before it can be guided by our own reason. The weakness of the in- fant, and the natural affection of the mother, plainly indicate the former ; and the natural credulity of youth, and authority of age, as plainly indicate the latter. The infant, by • See,contra, Priestley's" Examination," p. 86. ".Brown's Lect." lect. Ixxxiv.— H. proper nursing and care, acquires strength to walk without support. Reason hath likewise her infancy, when she must be carried in arms : then she leans entirely upon authority, by natural instinct, as if she was conscious of her own weakness ; and, without this support, she becomes ver- tiginous. When brought to maturity by proper culture, she begins to feel her own strength, and leans less upon the reason of others ; she learns to suspect testimony in some cases, and to disbelieve it in others ; and sets bounds to that authority to which she was at first entirely subject. But still, to the end of life, she finds a necessity ot borrowing light from testimony, where she has none within herself, and of leaning, in some degree, upon the reason of others, where she is conscious of her own imbe- cility. And as, in many instances, Reason, even in her maturity, borrows aid from testi- mony, so in others she mutually gives aid to it, and strengthens its authority. For, as we find good reason to reject testimony in some cases, so in others we find good reason to rely upon it with perfect security, in our most important concerns. The character, the number, and the disinterestedness of witnesses, the impossibility of collusion, and the incredibility of their concurring in their testimony without collusion, may give an irresistible strength to testimony, compared to which its native and intrinsic authority is very inconsiderable. Having now considered the general prin- ciples of the human mind which fit us for receiving information from our fellow-crea- tures, by the means of language, let us next consider the general principles which fit us for receiving the information of Nature by our acquired perceptions. It is undeniable, and indeed is acknow- ledged by all, that when we have found two things to have been constantly conjoined in the course of nature, the appearance of one of them is immediately followed by the con- ception and belief of the other. The for- mer becomes a natural sign of the latter; and the knowledge of their constant conjunc- tion in time past, whether got by experience or otherwise, is sufficient to make us rely with assurance upon the continuance of that conjunction. This process of the human mind is so familiar that we never think of inquiring into the principles upon which it is founded. We are apt to conceive it as a self-evident truth, that what is to come must be similar to what is past. Thus, if a certain degree of cold freezes water to-day, and has been known to do so in all time past, we have no doubt but the same degree of cold will freeze water to-morrow, or a year hence. That this is a truth which all men believe aa 198 OF THJi HUMAN MIND. soon as they understand it, I readily admit ; but the question is, Whence does its evi- dence arise ? Not from comparing the Ideas, surely. -For, when I compare the idea of cold with that of water hardened into a transparent solid body, I can per- ceive no connection between them : no man can shew the one to be the necessary effect of the other ; no man can give a shadow of reason why Nature hath conjoined them. But do we not learn their conjunction from experience ? True ; experience informs us that they have been conjoined in time past ; but no man ever had any experience of what is future : and this is the very question to be resolved, How we come to believe that the future will be like the past ? Hath the Author of nature pro- mised this ? Or were we admitted to his council, when he established the present laws of nature, and determined the time v>of their continuance. No, surely. In- deed, if we believe that there is a wise and good Author of nature, we may see a good reason why he should continue the same laws of nature, and the same connections of things, for a long time : because, if he did otherwise, we could learn nothing from what is past, and all our experience would be of no use to us. But, though this con- sideration, when we come to the use of rea- son, may confirm our belief of the contin- uance of the present course of nature, it is certain that it did not give rise to this belief ; for children and idiots have this be- lief as soon as they know that fire will burn them. It must, therefore, be the effect of ^jnstinct, not of reason. - The wise Author of our nature intended, that a great and necessary part of our know- ledge should be derived from experience, before we are capable of reasoning, and he hath provided means perfectly adequate to this intention. For, First, He governs nature by fixed laws, so that we find innumerable connections of things which continue from age to age. Without this stability of the course of nature, there could be no experi- ence ; or, it would be a false guide, and lead us into error and mischief. If there were not a principle of veracity in the human mind, men's words would not be signs of their thoughts : and if there were no regu- larity in the course of nature, no one thing could be a natural sign of another. Se- condly, He hath implanted in human minds an original principle by which we believe, and expect the continuance of the course of nature, and the continuance of those connec- * Compare Stewart's " Elements," vol. I., chap. iv , tj 5, p. 205. sixth edition j " Philosophical Essays," p. 74, eqq., fourth edition; Royer Collard, in Jouf- froy's "oeuvresde Rcid," t. IV., p. 279, sqn. ; with Priestley's " Examination," p. 86, sqq. I merely refer to works relative to lieid's doctrine. — H. tions which we have observed kt time past It is by this general principle of our nature, that, when two things have been found con- nected in time past, the appearance of the 'SQne produces the belief of the other. I think the ingenious author of the "Trea- tise of Human Nature" first observed, That our belief of the continuance of the laws of nature cannot be founded either upon know- ledge or probability : but, far from conceiv- ing it to be an original principle of the mind, he endeavours to account for it from his favourite hypothesis, That belief is no- thing but a certain degree of vivacity in the idea of the thing believed. I made a remark upon this curious hypothesis in the second chapter, and shall now make an- other. The belief which we have in perception, is a belief of the present existence of the object; that which we have in memory, is a belief of its past existence ; the belief of which we are now speaking is a belief of its future existence ; and in imagination there is no belief at all. Now, I would gladly know of this author, how one degree of vivacity fixes the existence of the object to the present moment ; another carries it back to time past ; a third, taking a con' trary direction, carries it into futurity ; and a fourth carries it out of existence alto- gether. Suppose, for instance, that I see the sun rising out of the sea : I remember to have seen him rise yesterday ; I believe he will rise to-morrow near the same place ; I can likewise imagine him rising in that place, without any belief at all. Now, ac- cording to this sceptical hypothesis, this perception, this memory, this foreknow- ledge, and this imagination, are all the same idea, diversified only by different degrees of vivacity. The perception of the sun rising is the most lively idea ; the memory of his rising yesterday is the same idea a little more faint ; the belief of his rising to-mor- row is the same idea yet fainter ; and the imagination of his rising is still the same idea, but faintest of all. One is apt to think, that this idea might gradually pass through all possible degrees of vivacity with- out stirring out of its place. But, if we think so, we deceive ourselves ; for no sooner does it begin to grow languid than it moves backward into time past. Supposing this to be granted, we expect, at least, that, as it moves backward by the decay of its vivacity, the more that vivacity decays it will go back the farther, until it remove quite out of sight. But here we are de- ceived again ; for there is a certain pe- riod of this declining vivacity, when, as if it had met an elastic obstacle in its mo- tion backward, it suddenly rebounds from the past to the future, without taking the present in its way. And now, having got Of SEEING. 199 into the regions of futurity, we are apt to think that it has room enough to spend all its remaining vigour : but still we are de- ceived ; for, by another sprightly bound, it mounts up into the airy region of imagina- tion. So that ideas, in the gradual declen- sion of their vivacity, seem to imitate the inflection of verbs in grammar. They be- gin with the present, and proceed in order to the preterite, the future, and the inde- finite. This article of the sceptical creed is indeed so full of mystery, on whatever side we view it, that they who hold that creed are very injuriously charged with incre- dulity ; for, to me, it appears to require as much faith as that of St Athanasius. However, we agree with the author of the " Treatise of Human Nature," in this, That our belief of the continuance of nature's laws is not derived from reason. It is an instinctive prescience of the operations of nature, very like to that prescience of human actions which makes us rely upon the testimony of our fellow-creatures ; and as, without the latter, we should be incapa- ble of receiving information from men by language, so, without the former, we should be incapable of receiving the information of nature by means of experience. All our knowledge of nature beyond our original perceptions, is got by experience, and consists in the interpretation of natural signs. The constancy of nature's laws connects the sign with the thing signified ; and, by the natural principle just now ex- plained, we rely upon the continuance of the connections which experience hath dis- covered ; and thus the appearance of the sign is followed by the belief of the thing signified. Upon this principle of our constitution, not only acquired perception, but all induc- tive reasoning, and all our reasoning from analogy, is grounded ; and, therefore, for want of another name, we shall beg leave to call it the inductive principle. It is from the force of this principle that we imme- diately assent to that axiom upon which all our knowledge of nature is built, That effects of the same kind must have the same cause ; for effects and causes, in the operations of nature, mean nothing but signs and the things signified by them. We perceive no proper causality or efficiency in any natural cause ; but only a connection established by the course of nature between it and what is called its effect. Anteced- ently to all reasoning, we have, by our con- stitution, an anticipation that there is » fixed and steady course of nature : and we have an eager desire to discover this course of nature. We attend to every conjunction of things which presents itself, and expect the continuance of that conjunction. And, when such a conjunction has been often observed, we conceive the things to be naturally connected, and the appearance of one, without any reasoning or reflection, carries along with it the belief of the other. If any reader should imagine that th« inductive principle may be resolved into what philosophers usually call the associ- ation of ideas, let him observe, that, by this principle, natural signs are not asso- ciated with the idea only, but with the be- lief of the things signified. Now, this can with no propriety be called an association of ideas, unless ideas and belief be one and the same thing. A child has found the prick of a pin conjoined with pain ; hence he believes, and knows, that these things are naturally connected ; he knows that the one will always follow the other. If any man will call this only an association of ideas, I dispute not about words, but I think he speaks very improperly. For, if we express it in plain English, it is a prescience that things which he hath found conjoined in time past, will be conjoined in time to come. And this prescience is not the effect of reasoning, but of an original principle of human nature, which I have called the inductive principle* This principle, like that of credulity, is unlimited in infancy, and gradually re- strained and regulated as we grow up. It leads us often into mistakes ; but is of in- finite advantage upon the whole. By it, the child once burnt shuns the fire ; by it, he likewise runs away from the surgeon by whom he was inoculated. It is better that he should do the last, than that he should not do the first. But the mistakes we are led into by these two natural principles, are of a different kind. Men sometimes lead us into mis- takes, when we perfectly understand their language, by speaking Ues. But Nature never misleads us in this way : her lan- guage is always true ; and it is only by misinterpreting it that we fall into error. There must be many accidental conjunc- tions of things, as well as natural connec- tions ; and the former are apt to be mis- taken for the latter. Thus, in the instance above mentioned, the child connected the pain of inoculation with the surgeon ; whereas it was really connected with the incision only. Philosophers, and men of science, are not exempted from such mis- takes ; indeed, all false reasoning in philo- sophy is owing to them ; it is drawn from experience and analogy, as well as just rea- soning, otherwise it could have no verisimili- tude ; but the one is an unskilful and rash, * This objection to the solution, on the ground of association, is unsound. It is generally admitted thai the term " Association of Jdeas" is inadequate ; the law of association extending not only to Ideas, but to all our mental modifications. — H 200 OF THE HUMAN MIND. the other a just and legitimate interpreta- tion of natural signs. If a child, or a man of common understanding, were put to interpret a book of science, written in his mother-tongue, how many blunders and mistakes would he be apt to fall into ? Yet he knows as much of this language as is necessary for his manner of life. The language of Nature is the universal study ; and the students are of different classes. Brutes, idiots, and children em- ploy themselves in this study, and owe to it all their acquired perceptions. Men of com- mon understanding make a greater pro- gress, and learn, by a small degree of reflection, many things of which children are ignorant. Philosophers fill up the highest form in this school, and are critics in the language of nature. All these different classes have one teacher — Experience, enlightened by the inductive principle. Take away the light of this inductive principle, and Ex- perience is as blind as a mole : she may, indeed, feel what is present, and what im- mediately touches her ; but she sees nothing that is either before or behind, upon the right hand or upon the left, future or past. The rules of inductive reasoning, or of a just interpretation of Nature, as well as the fallacies by which we are apt to misinter- pret her language, have been, with wonder- ful sagacity, delineated by the great genius of Lord Bacon : so that his " Novum Organum" may justly be called " A Gram- mar of the Language of Nature." It adds greatly to the merit of this work, and atones for its defects, that, at the time it was written, the world had not seen any tole- rable model of inductive reasoning," from which the rules of it might be copied. The arts of poetry and eloquence were grown up to perfection when Aristotle described them ; but the art of interpreting Nature was yet in embryo when Bacon delineated its manly features and proportions. Aristotle drew his rules from the best models of those arts that have yet appeared ; but the best models of inductive reasoning that have yet appeared, which I take to be the third book of the "Principia," and the " Optics," of Newton, were drawn from Bacon's rules. The purpose of all those rules, is to teach us to distinguish seeming or apparent connections of things, in the course of nature, from such as are real. They that are unskilful in inductive reasoning, are more apt to fall into error in their reasonings from the phenomena of nature than in their acquired perceptions ; because we often reason from a few in- stances, and thereby are apt to mistake acci- dental conjunctions of things for natural • Yet Galileo whs anterior to Bacon, — H. connections : but that habit of passing, without reasoning, from the sign to the thing signified, which constitutes acquired perception, must be learned by many in- stances or experiments ; and the number of experiments serves to disjoin those things which have been accidentally conjoined, as well as to confirm our belief of natural connections. From the time that children begin to use their hands, Nature directs them to handle everything over and over, to look at it while they handle it, and to put it in va- rious positions, and at various distances from the eye. We are apt to excuse this as a childish diversion, because they must be doing something, and have not reason to entertain themselves in a more manly way. But, if we think more justly, we shall find, that they are engaged in the most serious and important study ; and, if they had all the reason of a philosopher, they could not be more properly employed. For it is this childish employment that enables them to make the proper use of their eyes. They are thereby every day acquiring habits of perception, which are of greater importance than anything we can teach them. The original perception! which Nature gave them are few, and in- sufficient for the purposes of life ; and, therefore, she made them capable of ac- quiring many more perceptions by habit. And, to complete her work, she hath given them an unwearied assiduity in applying to the exercises by which those perceptions are acquired. This is the education which Nature gives to her children. And, since we have fallen upon this subject, we may add, that another part of Nature's education is, That, by the course of things, children must often exert all their muscular force, and employ all their ingenuity, in order to gratify their curiosity, and satisfy their little appetites. What they desire is only to be obtained at the expense of labour and patience, and many disappointments. By the exercise of body and mind necessary for satisfying their desires, they acquire agility, strength, and dexterity in their motions, as well as health and vigour to their constitutions ; they learn patience and perseverance; they learn to bear pain without dejection, and disappointment without despondence. The education of Nature is most perfect in savages, who have no other tutor ; and we see that, in the quickness of all their senses, in the agility of their motions, in the hardi- ness of their constitutions, and in the strength of their minds to bear hunger, thirst, pain, and disappointment, they com- monly far exceed the civilized. A most ingenious writer, on this account, seems to prefer the savage life to that of society. Conclusion. 201 But the education of Nature could never of itself produce a Eousseau. It is the intention of Nature that human educa- tion should be joined to her institution, in order to form the man. And she hath fitted us for human education, by the natural principles of imitation and credulity, which discover themselves almost in infancy, as well as by others which are of later growth. When the education which we receive from men, does not give scope to the educa- tion of Nature, it is wrong directed ; it tends to hurt our faculties of perception, and to enervate both the body and mind. Nature hath her way of rearing men, as she hath of curing their diseases. The art of medi- cine is to follow Nature, to imitate and to assist her in the cure of diseases ; and the art of education is to follow Nature, to assist and to imitate her in her way of rearing men. The ancient inhabitants of the Baleares followed Nature in the man- ner of teaching their children to be good archers, when they hung their dinner aloft by a thread, and left the younkers to bring it down by their skill in archery. The education of Nature, without any more human care than is necessary to pre- serve life, makes a perfect savage. Human education, joined to that of Nature, may make a good citizen, a skilful artisan, or a well-bred man ; but reason and reflection must superadd their tutory, in order to produce a Rousseau, a Bacon, or a Newton. Notwithstanding the innumerable errors committed in human education, there is hardly any education so bad as to be worse than none. And I apprehend that, if even Rousseau were to choose whether to educate a son among the French, the Italians, the Chinese, or among the Eskimaux, he would not give the preference to the last. When Reason is properly employed, she will confirm the documents of Nature, which are always true and wholesome ; she will distinguish, in the documents of human education, the good from the bad, rejecting the last with modesty, and adhering to the first with reverence. Most men continue all their days to be just what Nature and human education made them. Their manners, their opinions, their virtues, and their vices, are all got by habit, imitation, and instruction ; and rea- son has little or no share in forming them. CHAPTER VII. Conclusion. CONTAINING REFLECTIONS UPON THE OPINIONS OP PHILOSOPHERS ON THIS SUBJECT. There are two ways in which men may form their notions and opinions concerning the mind, and concerning its powers and oper- ations. The first is the only way that leads to truth ; but it is narrow and rugged, and few have entered upon it. The second is broad and smooth, and hath been much beaten, not only by the vulgar, but even by philosophers; it is sufficient for common life, and is well adapted to the purposes of the poet and orator : but, in philosophical dis- quisitions concerning the mind, it leads to error and delusion. We may call the first of these ways, the way of reflection. When the operations of the mind are exerted, we are conscious of them ; and it is in our power to attend to them, and to reflect upon them, until they become familiar objects of thought. This is the only way in which we can form just and accurate notions of those operations. But this attention and reflection is so diffi- cult to man, surrounded on all hands by external objects which constantly solicit his attention, that it has been very little prac- tised, even by philosophers. In the course of this inquiry, we have had many occa- sions to shew how little attention hath been given to the most familiar operations of the senses. The second, and the most common way, in which men form their opinions concern- ing the mind and its operations, we may call the way of analogy. There is nothing in the course of nature so singular, but we can find some resemblance, or at least some analogy, between it and other things with which we are acquainted. The mind na- turally delights in hunting after such analo- gies, and attends to them with pleasure. From them, poetry and wit derive a great part of their charms ; and eloquence, not a little of its persuasive force. Besides the pleasure we receive from analogies, they are of very considerable use, both to facilitate the conception of things, when they are not easily apprehended with- out such a handle, and to lead us to probable conjectures about their nature and qualities, when we want the means of more direct and immediate knowledge. When I con- sider that the planet Jupiter, in like manner as the earth, rolls round his own axis, and revolves round the sun, and that he is en- lightened by several secondary planets, as the earth is enlightened by the moon, I am apt to conjecture, from analogy, that, as the earth by these means is fitted to be the habitation of various orders of animals, so the planet Jupiter is, by the like means, fitted for the same purpose : and, having no argument more direct and conclusive to de- termine me in this point, I yield, to this analogical reasoning, a degree of assent proportioned to its strength. When I observe that the potato plant very much 202 OF THE HUMAN MiNfl. resembles the solarium in its flower and fructification, and am informed that the last is poisonous, I am apt from analogy to have some suspicion of the former : but, in this case, I have access to more direct and certain evidence ; and, therefore, ought not to trust to analogy, which would lead me into an error. Arguments from analogy are always at hand, and grow up spontaneously in a fruitful imagination ; while arguments that are more direct and more conclusive often require painful attention and appli- cation : and therefore mankind in gene- ral have been very much disposed to trust to the former. If one attentively examines the systems of the ancient philosophers, either concerning the material world, or concerning the mind, he will find them to be built solely upon the foundation of ana- logy. Lord Baeon first delineated the strict and severe method of induction ; since his time, it has been applied with very happy success in some parts of natural philosophy — and hardly in anything else. But there is no subject in which mankind are so much' disposed to trust to the analogical way of thinking and reasoning, as in what concerns the mind and its operations ; because, to form clear and distinct notions of those operations in the direct and proper way, and to reason about them, requires a habit of attentive reflection, of which few are capable, and which, even by those few, cannot be attained without much pains and labour. Every man is apt to form his notions of things difficult to be apprehended, or less familiar, from their analogy to things which are more familiar. Thus, if a man bred to the seafaring life, and accustomed to think and talk only of matters relating to naviga- tion, enters into discourse upon any other subject, it is well known that the language and the notions proper to his own profes- sion are infused into every subject, and all things are measured by the rules of naviga- tion ; and, if he should take it into his head to philosophize concerning the faculties of the mind, it cannot be doubted but he would draw his notions from the fabric of his ship, and would And in the mind, sails, masts, rudder, and compass.* Sensible objects, of one kind or other, do no less occupy and engross the rest of man- kind, than things relating to navigation the seafaring man. For a considerable part of life, we can think of nothing but the objects of sense ; and, to attend to objects of an- other nature, so as to form clear and dis- tinct notions of them, is no easy matter, even after we come to years of reflection. • See " Essays on the Intellectual Powers," Ess. VI., ch. viii., Nos. 2 and 6.— H. The condition of mankind, therefore, affords good reason to apprehend that their lan- guage, and their common notions concern- ing the mind and its operations, will be ana- logical, and derived from the objects oi sense ; and that these analogies will be apt to impose upon philosophers, as well as upon the vulgar, and to lead them to ma- terialize the mind and its faculties : and experience abundantly confirms the truth of this. How generally men of all nations, and in all ages of the world, have conceived the soul, or thinking principle in man, to be some subtile matter, like breath or wind, the names given to it almost in all languages sufficiently testify. * We have words which are proper, and not analogical, to express the various ways in which we perceive ex- ternal objects by the senses — such as feel- ing, sight, taste ; but we are often obliged to use these words analogically, to express other powers of the mind which* are of a very different nature. And the powers which imply some degree of reflection, have generally no names but such as are analo- gical. The objects of thought are said to be in the mind — to be apprehended, com* prehended, conceived, imagined, relained f weighed, ruminated.* It does not appear that the notions ol the ancient philosophers, with regard to the nature of the soul, were much more re- fined than those of the vulgar, or that they were formed in any other way. We shall distinguish the philosophy that regards our subject into the old and the new. The old reached down to Des Cartes, who gave it a fatal blow, of which it has been gradually expiring ever since, and is now almost ex- tinct. Des Cartes is the father of the new philosophy that relates to this subject ; but it hath been gradually improving since his time, upon the principles laid down by him. The old philosophy seems to have been purely analogical ; the new is more derived from reflection, but still with a very con- siderable mixture of the old analogical no- tions. Because the objects of sense consist of matter and form, the ancient philosophers conceived everything to belong to one of these, or to be made up of both. Some, therefore, thought that the soul is a parti- cular kind of subtile matter, separable from our gross bodies ; others thought that it is only a particular form of the body, and in- separable from it. t For there seem to have • The examples that might be given of these, would, I find, exceed the limits of a foot-note— H. t It would, however, he a very erroneous assump- tion to hold, that those who viewed the soul as a form inseparable from the body, denied the existence, and the independent existence, of any mental principle after the dissolution of ihe material oiganism. Thus, Anstotledefines thesoul, the Form or Entelechjoran CONCLUSION. 203 been some among the ancients, as well as among the moderns 3 who conceived that a certain structure or organization of the body, is all that is necessary to render it sensible and intelligent.* The different powers of the mind ware, accordingly, by the last sect of philosophers, conceived to belong to different. parts of the body — as the heart, the brain, the liver, the stomach, the blood.f They who thought that the soul is a sub- tile matter, separable from the body, dis- puted to which of the four elements it be- longs— whether to earth,- water, air, or fire. Of the three last, each had its particular advocates.^ But some were of opinion, that it partakes of all the elements ; that it must have something in its composition similar to everything we perceive ; and that we perceive earth by the earthly part ; water, by the watery part; and fire, by the fiery part of the soul.§ Some philoso- phers, not satisfied with determining of what kind of matter the soul is made, in- quired likewise into its figure, which they determined to be spherical, that it might be the more fit for motion. || The most spiritual and sublime notion concerning the nature of the soul, to be met with among the ancient philosophers, I conceive to be that of the Platonists, who held that it is made of that celestial and incorruptible matter of which the fixed stars were made, and, therefore, has a natural tendency to rejoin its proper element.^" I am at a loss organized body j and yet he, hypothetically at least, admits that N5s, or Intelligencp, is- adventitious to this animated organ ism „ and, therefore, possibly, and even probably,, separable from it, and immortal. The term sim/ in this 'instance is not adequate to the Intellec- tual Ego.— H. * Thus Parmenides: — 'ii? yotg ixara/ Z%ti x%£.what I shall hereafter more fully advert to— that Reid's criticism of Locke, here and elsewhere, proceeds upon the implication that the English philosopher attached the same restricted meaning to the term Sensation that he did himself. But this is not the case. Locke employed Sensation to denote both the idei and the sentiment of the Cartesians— both the perception and the sensation of Reid. To confound this distinction was, indeed, wrong j but this is a separate and special ground of censure, and, in a general criticism of Locke's doc. CONCLUSION. 209 There is no doctrine in the new system which more directly leads to scepticism than this. And the author of the " Trea- tise of Human Nature" knew very well how to use it for that purpose ; for, if you maintain that there is any such existence as body or spirit, time or place, cause or effect, he immediately catches you between the horns of this dilemma ; your notions of these existences are either ideas of sensa- tion, or ideas of reflection : if of sensation, from what sensation are they copied ? if of reflection, from what operation of the mind are they copied ? It is indeed to be wished mat those who have written much about sensation, and about the other operations of the mind, had likewise thought and reflected much, and with great care, upon those operations ; but is it not very strange that they will not allow it to be possible for mankind to think of anything else ? The account which this system gives of our judgment and belief concerning things, is as far from the truth as the account it gives of our notions or simple appre- hensions. It represents our senses as hav- ing no other office but that of furnishing the mind with notions or simple appre- hensions of things ; and makes our judg- ment and belief concerning those things to be acquired by comparing our notions to- gether, and perceiving their agreements or disagreements. We have shewn, on the contrary, that every operation of the senses, in its very nature, implies judgment or belief, as well as simple apprehension. Thus, when I feel the pain of the gout in my toe, I have not only a notion of pain, but a belief of its existence, and a belief of some disorder in my toe which occasions it ; and this belief is not produced by comparing ideas, and perceiving their agreements and disagree- ments ; it is included in the very nature of the sensation. When I peiceive a tree before me, my faculty of seeing gives me not only a notion or simple apprehension of the tree, but a belief of its existence, and of its figure, distance, and magnitude ; and this judgment or belief is not got by com- paring ideas, it is included in the very na- ture of the perception. We have taken notice of several original principles of belief in the course of this inquiry; and trine, the fact ihat hedid so confound perception pro. perand sensation proper, should always be taken into account. But, waving this, what is gained by the distinction in Keid's hands? Inhis doctrine, space, motion, &c as perceived, are only conceptions, only modifications of self, suggested, in some unknown way, on occasion of the impression made on the sense : consequently, in the one doctrine as in the other, what is known is nothing beyond the affections of the thinking subject.itsell j and this is the only basis required by the idealist anil sceptic.for the foundation of their systems — H. when other faculties of the mind are exa- mined, we shall find more, which have not occurred in the examination of the five Such original and natural judgments are, therefore, a part of that furniture which Nature hath given to the human under- standing. They are the inspiration of the Almighty, no less than our notions or simple apprehensions. They serve to direct us in the common affairs of life, where our rea- soning faculty would leave us in the dark. They are a part of our constitution ; and all the discoveries of our reason are grounded upon them. They make up what is called the common sense of mankind ;* and, what is manifestly contrary to any of those first principles, is what we call absurd. The strength of them is good sense, which is often found in those who are not acute in reasoning. A remarkable deviation from them, arising from a disorder in the con- stitution, is what we call lunacy ; as when a man believes that he is made of glass. When a man suffers himself to be reasoned out of the principles of common sense, by metaphysical arguments, we may call this metaphysical lunacy ; which differs from the other species of the distemper in this, that it is not continued, but intermittent : it is apt to seize the patient in solitary and speculative moments ; but, when he enters into society, Common Sense recovers her authority. *f A clear explication and enu- meration of the principles of common sense, is one of the chief desiderata in logic. We have only considered such of them as oc- curred in the examination of the five senses. 5. The last observation that I shall make upon the new system, is, that, although it professes to set out in the way of reflection, and not of analogy, it hath retained some of the old analogical notions concerning the » See Note A — H. t No one admits this more promptly than the sceptic himself See Hume's " Treatise of Human Nature," Book I., Part lv., $ 7, and " Enquiry Concerning Human Understanding," $ 12, Part II. " Nature," says he in the latter, " is always too strong for principle ; and, though a Pyrrhoniari may throw himself or others into a momentary amazement and confusion by his profound reasonings, the first and most trivial event in life will put to flight all his doubts and scruples, and- leave him the same in every point of action and speculation with the philosopher* of every other sect, or with those who never con. cerned themselves in any-philosophical researches. When he awakes from his dream, he will be the first to'join in the laugh against himself, and to confess that all his objections are mere amusement, and car have-no other tendency than to shew the whimsical condition of mankind, who must act, and reason, and believe, though they are not able, by their most diligent enquiry, to satisfy themselves concerning the foundation of the opeiations, or to remove the objec- tions which may be raised against them " *' I.a Nature confond les Pyrrhoniens,'* (says Pascal,) " et la Raison confond les Dogmatistes." How can philosophy be realized ? is thus the grand question.— H. 210 OF THE HUMAN MIND. operations of the mind ; particularly, that things which do not now exist in the mind itself, eon only be perceived, remembered, or imagined, by means of ideas or images* of them in the mind, which are the imme- diate objects of perception, remembrance, and imagination. This doctrine appears evidently to be borrowed from the old sys- tem ; which taught that external things make impressions upon the mind, like the impressions of a seal upon wax ; that it i= by means of those impressions that we per- ceive, remember, or imagine them ; ai.d that those impressions must resemble the things from which they are taken. When we form our notions of the operations of the mind by analogy, this way of conceiving them seems to be very natural, and offers itself to our thoughts ; for, as everything which is felt must make some impression upon the body, we are apt to think that everything which is understood must make some impression upon the mind. From such analogical reasoning, this opinion of the existence of ideas or images of things in the mind, seems to have taken its rise, and to have been so universally received among philosophers. It was ob- served already, that Berkeley, hi one in- stance, apostatizes from this principle of the new system, by affirming that we have no ideas of spirits, aud that we can think of them immediately, without ideas. But I know not whether in this he has had any followers. There is some difference, like- wise, among modern philosophers with re- gard to the ideas or images by which we perceive, remember, or imagine sensible things. For, though all agree in the exist- ence of such images,-|- they differ about their place ; some placing them in a particular part of the brain, where the soul is thought to have her residence, and others placing them in the mind itself. Des Cartes held the first of these opinions ; J to which Newton seems likewise to have inclined ; for he proposes this query in his " Optics :" — " Annon sen- sorium animalium est locus cui substantia sentiens adest, et in quem sensibiles rerum species per nervos et cerebrum deferunt;ir, ut ibi prsesentes a prsesente sentiri ptis- • That is, Dy representative entities diffcrentfrom the modes of the mind itself. This doctrine, 1 have already.noticed, is attributed by Reidtoo universally to philosoph rs; and is also a comparatively unim- portant circumstance in relerence to the Idealist and Sceptic. See Note c— H. + See last note. Berkeley dirt hold the hypothesis of Ideas as understood by Reid. — H. J An unqualified error, arising from not tinder- standing the ambiguous language of Des C; rtes ; who. calls, by the common name of Ideas, both the organic motions in the brain, of which the mind, in his doctrine, necessarily knows nothing, and' the re. presentations in the ■mind itself, hyprrphysically de. lermined on occasion of those motions, and of which alone the mind iscognizant. But of this under the *" Jwbays on the Intellectual Powers." — H. sinfc ?" But Locke seems to place the ideas of sensible things in the mind ;* and that Berkeley, and the author of the " Treatise of Human Nature," were of the same opinion, is evident. The last makes a very curious application of this doctrine, by en- deavouring to prove from it, That the mind either is no substance, or that it is an ex- tended and divisible substance ; because the ideas of extension cannot be in a subject which is indivisible and unextended. I confess I think his reasoning in this, as in most cases, is clear and strong. For whether the idea of extension be only another name for extension itself, as Ber- keley and this author assert ; or whether the idea of extension be an image and resem- blance of extension, as Locke conceived ; I appeal to any man of common sense, whether extension, or any image of exten- sion, can be in an unextended and indi- visible subject. *f- But while I agree with him in his reasoning, I would make a differ- ent application of it. He takes it for grant- ed, that there are ideas of extension in the mind ; and thence infers, that, if it is at all a substance, it must be an extended and divisible substance. On the contrary, I take it for granted, upon the testimony of common sense, that my mind is a substance — that is, a permanent subject of thought ; and my reason convinces me that it is an unextended and indivisible substance ; and hence I infer that there cannot be in it anything that resembles extension. If this reasoning had occurred to Berkeley, it would probably have led him to acknow- ledge that we may think and reason con- cerning bodies, withouthaving ideas of them in the mind, as well as concerning spirits. I intended to have examined more par- ticularly and fully this doctrine of the ex- istence of ideas or images of things in the mind ; and likewise another doctrine, which is founded upon it — to wit, That judgment or belief is nothing but a perception of the agreement or disagreement of our ideas; but, having already shewn, through the course of this inquiry, that the operations of the mind which we have examined, give no countenance to either of these doctrines, and in many things contradict them, I have thought it proper to drop this part of my design. It may be executed with more advantage, if it is at all necessary, after in- quiring into some other powers of the human understanding. • Locke's opinion on this point is as obscure and doubtful as that of Des Cartes is clear and certain. But Reid is probably right— H + I do not recollect seeing any argument raised in favour of materialism, from the fact, that, s/wce or extension is. a notion necessary to the mind ; and y**t it might, with some ..how of plausibility, be nmn. tained.that extension is a necessary form or thought, because the thinking principle isitsell exten. ed — H CONCLUSION. 211 Although we have examined only the five senses, and the principles of the human mind which are employed about them, or such as have fallen in our way in the course of this examination, we shall leave the further prosecution of this inquiry to future deliberation. The powers of memory, of imagination, of taste, of reasoning, of moral perception, the will, the passions, the affec- tions, and all the active powers of the soul, present a vast and boundless field of philo- sophical disquisition, which the author of this inquiry is far, from thinking himself able to survey with accuracy. Many authors of ingenuity, ancient and modern, have made excursions into this vast territory, and have communicated useful observations : but there is reason to believe that those who have pretended to give us a map of the whole, have satisfied themselves with a very inaccurate and incomplete survey. If Ga- lileo had attempted a complete system of natural philosophy, he had, probably, done little service to mankind : but by confining himself to what was within his comprehen- sion, he laid the foundation of a system of knowledge, which rises by degrees, and does honour to the human understanding. Newton, building upon this foundation, and, in like manner, confining his inquiries to the law of gravitation and the properties of light, performed wonders. If he had at- tempted a great deal more, he had done a great deal less, and perhaps nothing at all. Ambitious of following such great examples, with unequal steps, alas ! and unequal force, we have attempted an inquiry only into one little corner of the human mind — that corner which seems to be most exposed to vulgar observation, and to be most easily comprehended ; and yet, if we have deline- ated it justly, it must be acknowledged that the accounts heretofore given of it weie very lame, and wide of the truth. ESSAYS ON I HR INTELLECTUAL POWERS OF MAIN By THOMAS HEID, D.D., F.R.S.E., PROFESSOR O? MORAL PniLOSOPHT IN THE UNIVERSITY OF GLASGOW. '* V\ hn hath put wisdom in the inward parts? '" — Job f-> This impression of the " Essnys on the Intellectual Powers," is made from me only authentic edition — that of 17*55, in 4to. For the convenience of reference the pages of that edition are distinguished in the present ; and by these pages I shall always, in the notes, prospectively, quote. They will be found marked both ill the text and on the lower margin. — H. DEDICATION. TO MR DUGALD STEWART, LATELY PROFESSOR OP MATHEMATICS, NOW PROFESSOR OF MORAL PHILOSOPHY, DR JAMES GREGORY, PROFESSOR OF THE THEORY OF PHYSIO IN THE UNIVERSITY OF EDINBURGH. 41 Mv Dear Friends, — I know not to whom I can address these Essays with more propriety than to you ; not only on account of a friendship begun in early life on your part, though in old age on mine, and in one of you I may say hereditary ; nor yet on account of that correspondence in our literary pursuits and amusements, which has always given me so great plea- sure ; but because, if these Essays have any merit, you have a considerable share in it, having not only encouraged me to hope that [iv. ] they may be useful, but favoured me with your observations on every part of them, both before they were sent to the press, and while they were under it. I have availed myself of your observa- tions, so as to correct many faults that might otherwise have escaped me ; and I have- a very grateful sense of your friend- ship, in giving this aid to one who stood much in need of it ; having no shame, but much pleasure, in being instructed by those who formerly were my pupils, as one of you was. It would be ingratitude to a man whose memory I most highly respect, not to men- tion my obligations to the late Lord Karnes, for the concern he was pleased to take in this Work. Having seen a small part of it, he urged me to carry it on ; took acount of my progress from time to time ; revised it more than once, as far as it was carried, before his death ; and gave me his observa- tions on it, both with respect to the matter and the expression. On some points we • See above, in [iii.-vi.~l ' Correspondence," p. 65, a.— II. differed in opinion, and debated them keenly, both in conversation and by many letters, without any abatement of his affec- tion, or of his zeal for the work's being carried on and published : for he had too much liberality of mind not to allow to [ v. ] others the same liberty in judging which he claimed to himself. It is difficult to say whether that worthy man was more eminent in active life or in speculation. Very rare, surely, have been the instances where the talents for both were united in so eminent a degree. His genius and industry, in many differ, ent branches of literature, will, by his works, be known to posterity : his private virtues and public spirit, his assiduity. through a long and laborious life, in many honourable public offices with which he was entrusted, and his zeal to encourage and promote everything that tended to the improvement of his country in laws, litera- ture, commerce, manufactures, and agricul- ture, are best known to his friends and contemporaries. The favourable opinion which he, and you my friends, were pleased to express of this work, has been my chief encourage- ment to lay it before the public ; and per- haps, without that encouragement, it had never seen the light : for I have always found, that, without social intercourse, even a favourite speculation languishes ; and that we cannot help thinking the better of our own opinions [vi. ] when they are approved by those whom we esteem good judges. You know that the substance of these Essays was delivered annually, for more 2 id FKEFAUE. than twenty years, in Lectures to a large body of the more advanced students in this University, and for several years before, in another University. Those who heard me with attention, of whom I presume there are some hundreds alive, will recognise the doctrine which they heard, some of them thirty years ago, delivered to them more diffusely, and with the repetitions and illus- trations proper for such audiences. I am afraid, indeed, that the more intel- ligent reader, who is conversant in such abstract subjects, may think that there are repetitions still left, which might be spared. Such, I hope, will consider, that what to one reader is a superfluous repetition, to the greater part, less conversant in such subjects, may be very useful. If this apo- logy be deemed insufficient, and be thought to be the dictate of laziness, I claim some indulgence even for that laziness, at my period of life, [vii.] You who are in the prime of life, with the vigour which it inspires, will, I hope, make more happy advances in this or in any other branch of science to which your taleui * may be applied. Tho. Rbid. Glasgow College, June 1, 1785. PREFACE. Human knowledge may be reduced to two general heads, according as it relates to body or to mind ; to things material or to things intellectual.* The whole system of bodies in the uni- verse, of which we know but a very small part, may be called the Material World ; the whole system of minds, from the infinite Creator to the meanest creature endowed with thought, may be called the Intellectual World. These are the two great kingdoms of nature-) - that fall within our notice; and about the one, or the other, or things pertaining to them, every art, every science, and every human thought is employed ; nor can the boldest flight of imagination carry us beyond their limits. Many things there are, indeed, regarding the nature and the structure both of body and of mind, which our faculties cannot reach ; many difficulties which the ablest philosopher cannot resolve : but of other » See Stewart 's "Life and Writings of Reid," supra, p 14 ; and his " Elements," vol. L, introduc- tion ; Jouflroy, in the preface to his " Oeuvres de Reid," t. i., pp. 23-iJ3. 'this important Preface will soon be made generally accessible. to the British pub- lic bya highly competent translator. — H. f The term Nature is used sometimes in a wider, sometimes in a narrower extension. When employed in its most extensive meaning, it embraces the two worlds of mind and matter. When employed in its more restricted signification, it is a synonyme for the latter only, and is then used in contradistinction to the former. In the Greek philosophy, the word eC/rti was general in its meaning ; and the great branch of philosophy styled " physical or phytioLt- gical," included under it not only the sciences of matter, but also those of mind. V\ ith us, the term Nature is more vaguely extensive than the terms, physics, i hi. su at, physiology, physiological, or even tn .n the adjective natural ; whereas, in the philo- sophy of Germany, Nntur, and its correlatives, wh ther of Greek or Lalin derivation, are, in general, exprcssiveof the woild of matter in contrast to the world of- inielligcnce. — H. [vii.-2] natures, if any other there be, we have no knowledge, no conception at all. That everything that exists must be either corporeal or incorporeal is evident. But it is not so evident that everything [2] that exists must either be corporeal or endowed with thought. Whether there be in the universe beings which are neither extended, solid, and inert, like body, nor active and intelligent, like mind, seems to be beyond the reach of our knowledge. There appears to be a vast interval between body and mind ; and whether there be any interme- diate nature that connects them together, we know not. We have no reason to ascribe intelli- gence, or even sensation, to plants; yet there appears in them an active force and energy, which cannot be the result of any arrangement or combination of inert matter. The same thing may be said of those powers by which animals are nourished and grow, by which matter gravitates, by which mag- netical and electrical bodies attract and repel each other, and by which the parts of solid' bodies cohere. Some have conjectured that the pheno- mena of the material world which require active force, are produced by the continual operation of intelligent beings : others have conjectured that there may be in the uni- verse, beings that are active, without in- telligence, which, as a kind of incorporeal machinery, contrived by the supreme wis- dom, perform their destined task without any knowledge or intention. * But, laying aside conjecture, and all pretences to deter- mine in things beyond our reach, we must * Like the tripods of Vulcan — 0^g« oi KVTO.uattot duov ^t/jy..a.T' iy£tm<— H. PREFACE. 217 rest in this, that body and mind are the only kinds of being of which we can have any knowledge, or can form any concep- tion. If there are other kinds, they are not discoverable by the faculties which God hath given us ; and, with regard to Us, are as if they were not. [3] As, therefore, all our knowledge is con- fined to body and mind, or things belonging to them, there are two great branches of philosophy, one relating to body, the other to mind. The properties of body, and the laws that obtain in the material system, are the objects of natural philosophy, as that word is now used. The branch which crcats of the nature and operations of minds lias, by some, been called Pneumatology.* And to the oneor the other of these branches, the principles of all the sciences belong. What variety there may be of minds or thinking beings, throughout this vast uni- verse, we cannot pretend to say. We dwell in a little corner of God's dominion, dis- joined from the rest of it. The globe which we inhabit is but one of seven planets that encircle our sun. What various orders of beings may inhabit the other six, their secondaries, and the comets belonging to our system, and how many other suns may be encircled with like systems, are things altogether hid from us. Although human reason and industry have discovered, with great accuracy, the order and distances of the planets, and the laws of their motion, we have no means of corresponding with them That they may be the habitation of animated beings, is very probable ; but of the nature or powers of their inhabitants, we are perfectly ignorant. Every man is conscious of a thinking principle, or mind, in himself ; and we have sufficient evidence of a like principle in other men. The actions of brute animals shew that they have some thinking principle, though of a nature far inferior to the human mind. And everything about us may convince us of the existence of a supreme mind, the Maker and Governor of the universe. These are all the minds of which reason can give us any certain knowledge. [4] The mind of man is the noblest work of God which reason discovers to us, and, therefore, on account of its dignity, deserves our study. ■)• It must, indeed, be acknow- ledged, that, although it is of all objects the nearest to us, and seems the most within our reach, it is very difficult to attend to its operations so as to form a distinct notion • Now properly superseded by the term Psychol- ogy ; to which no competent objection can be made, and which affords us — what the various clumsy peri- phrases in use do not — a convenient adjective,/>s#cAo- (ogt'eah — H. t " On earth," says a forgotten philosopher, ** there is nothing great but Man ; in man there is nothing great but Mind." — H. [3—51 of them ; and on that account there is no branch of knowledge in which the ingenious and speculative have fallen into so great errors, and even absurdities. These errors and absurdities have given rise to a general prejudice against all inquiries of this nature. Because ingenious men have, for many ages, given different and contradictory accounts of the powers of the mind, it is concluded that all speculations concerning them are chimerical and visionary. But whatever effect this prejudice may have with superficial thinkers, the judicious will not be apt to be carried away with it. About two hundred years ago, the opinions of men in natural philosophy were as various and as contradictory as they are now con- cerning the powers of the mind. Galileo, Torricelli, Kepler, Bacon, and Newton, had the same discouragement in their attempts to throw light upon the material system, as we have with regard to the in- tellectual. If they had been deterred by such prejudices, we should never have reaped the benefit of their discoveries, which do honour to human nature, and will make their names immortal. The motto which Lord Bacon prefixed to some of his writings was worthy of his genius, Iaveniam viam aut faciam.* There is a natural order in the progress of the sciences, and good reasons may be assigned why the philosophy of body should [5] be elder sister to that of mind, and of a quicker growth ; but the last hath the prin- ciple of life no less than the first, and will grow up, though slowly, to maturity. The remains of ancient philosophy upon this subject, are venerable ruins, carrying the marks of genius and industry, sufficient to inflame, but not to satisfy our curiosity. In later ages, Des Cartes was the first that pointed out the road we ought to take in those dark regions. Malebranche, Arnauld, Locke, Berkeley, Buffier, Hutcheson, Butler, Hume, Price, Lord Karnes, have laboured to make discoveries — nor have they laboured in vain ; for, however different and contrary their conclusions are, how- ever sceptical some of them, they have all given new light, and cleared the way to those who shall come after them. We ought never to despair of human genius, but rather to hope that, in time, it may produce a system of the powers and operations of the human mind, no less cer- tain than those of optics or astronomy. This is the more devoutly to be wished, that a distinct knowledge of the powers of the mind would undoubtedly give great light to many other branches of science. Mr Hume hath justly observed, that " all the • See Mr Stewart's "Philosophical Essay«," Pre liminary Dissertation, ch. ii 218 PREFACE. sciences have a relation to human nature ; and, however wide any of them may seem to run from it, they still return back by one passage or another. This is the centre and capital of the sciences,* which, being once masters of, we may easily extend our con- quests everywhere." The faculties of our minds are the tools and engines we must use in every disquisi- tion ; and the better we understand their [6] nature and force, the more successfully we shall be able to apply them. Mr Locke gives this account of the occasion of his entering upon his essay concerning human understanding : — " Five or six friends," says he, " meeting at my chamber, and dis- coursing on a subject very remote from this, found themselves quickly at a stand by the difficulties that rose on every side. After we had for a while puzzled ourselves, without coming any nearer to a resolution of those doubts that perplexed us, it came into my thoughts that we took a wrong course ; and that, before we set ourselves upon inquiries of that nature, it was neces- sary to examine our own abilities, and see what objects our understandings were fitted or not fitted to deal with. This I proposed to the company, who all readily assented ; and thereupon it was agreed that this should be our first enquiry." If this be commonly the cause of perplexity in those disquisi- tions which have least relation to the mind, it must be so much more in those that have an immediate connection with it. The sciences maybe distinguished into two classes, according as they pertain to the material or to the intellectual world. The various parts of natural philosophy, the mechanical arts, chemistry, medicine, and agriculture, belong to the first ; but, to the last, belong grammar, logic, rhetoric, na- * Hume probably had the saying of Folybius in his eye, who calls History the mother city dtMjwflTe- \i s ) of Philosophy.— H. [«■ n tural theology, morals, jurisprudence, law. politics, and the fine arts. The know- ledge of the human mind is the root from which these grow, and draw their nourish- ment.* Whether, therefore, we consider the dignity of this subject, or its subser- viency to science in general, and to the noblest branches of science in particular, it highly deserves to be cultivated. [7] A very elegant writer, on the sublime and beautiful,f concludes his account of the passions thus : — " The variety of the pas- sions is great, and worthy, in every branch of that variety, of the most diligent inves- tigation. The more accurately we search into the human mind, the stronger traces we everywhere find of His wisdom who mad 6 it. If a discourse on the use of the parts of the body may be considered as a hymn to the Creator,} the use of the passions, which are the organs of the mind, cannot be barren of praise to Him, nor unproductive to ourselves of that noble and uncommon union of science and admiration, which a contemplation of the works of infinite Wis- dom alone can afford to a rational mind ; whilst referring to Him whatever we find of right, or good, or fair, in ourselves, dis- covering His strength and wisdom even in our own weakness and imperfection, honouring them where we discover them clearly, and adoring their profundity where we are lost in our search, we may be inquisitive with- out impertinence, and elevated without pride ; we may be admitted, if I may dare to say so, into the counsels of the Almighty, by a consideration of his works. This ele- vation of the mind ought to be the principal end of all our studies, which, if they do not in some measure effect, they are of very little service to us." * It is justly observed by M. Jouffroy, that the division here enounced is not in principle identical with that previously propounded. — H. f Burke.— H. J Galen is referred to.— H. ESSAYS ON TH3 INTELLECTUAL POWERS OF MAN. ESSAY I. PRELIMINARY. CHAPTER I. EXPLICATION OP WORDS. There is no greater impediment to the advancement of knowledge than the ambi- guity of words. To this chiefly it is owing that we find sects and parties in most branches of science; and disputes which are carried on from age to age, without being brought to an issue. Sophistry has been more effectually ex- cluded from mathematics and natural philosophy than from other sciences. In mathematics it had no place from the begin- ning ; mathematicians having had the wis- dom to define accurately the terras they use, and to lay down, as axioms, the first prin- ciples on which their reasoning is grounded. Accordingly, we find no parties among ma- thematicians, and hardly any disputes.* [10] In natural philosophy, there was no less sophistry, no less dispute and uncertainty, than in other sciences, until, about a cen- tury and a half ago, this science began to be built upon the foundation of clear defini- tions and self-evident axioms. Since that time, the science, as if watered with the dew of Heaven, hath grown apace ; dis- putes have ceased, truth hath prevailed, and the science hath received greater in- crease In two centuries than in two thous- and years before. It were to be wished that this method, which hath been so successful in those branches of science, were attempted in others ; for definitions and axioms are the foundations of all science. But that defini- tions may not be sought where no defini- tion can be given, nor logical definitions be attempted where the subject does not admit of them, it may be proper to lay down some general principles concerning definition, for • It was not the superior wisdom of mathema- ticians, but. the simple and palpable character of their object-matter, which determined the difference.— H. [9-11] the sake of those who are less conversant in this branch of logic. When one undertakes to explain any art or science, he will have occasion to use many words that are common to all who use the same language, and some that are peculiar to that art or science. Words of the last kind are called terms of the art, and ought to be distinctly explained, that their meaning may be understood. A definition* is nothing else but an ex- plication of the meaning of a word, by words whose meaning is already known. Hence it is evident that every word cannot be defined ; for the definition must consist of words ; and there could be no definition, if there were not words previously understood without definition. Common words, there- fore, ought to be used in their common acceptation ; and, when they have different acceptations in common language, these, when it is necessary, ought to be distin- guished. But they require no definition. It is sufficient to define words that are un- common, or that are used in an uncommon meaning. It may farther be observed, that there are many words, which, though they may need explication, cannot be logically defined. A [ 1 1 ] logical definition — that is, a strict and proper definition — must, express the kind [genus] of the thing defined, and the spe- cific difference by which the species defined is distinguished from every other species belonging to that kind. It is natural to the mind of man to class things under various kinds, and again to subdivide every kind into its various species. A species may often be subdivided into subordinate species, and then it is considered as a kind. From what has been said of logical defi- nition, it is evident, that no word can be logically defined which does not denote » # In what follows, there is a confusion of defini- tions verbal and real, which should have been care- fully distinguished.— H. '220 ON THE INTELLECTUAL POWERS. QeSSAY I. species ; because such things only can have a specific difference ; and a specific differ- ence is essential to a logical definition. On this account there can be no logical definition of individual things, such as London or Paris. Individuals are distin- guished either by proper names, or by acci- dental circumstances of time or place ; but they have no specific difference ; and, there- fore, though they may be known by pro- per names, or may be described by circum- stances or relations, they cannot be denned. * It is no less evident that the most general words cannot be logically defined, because there is not a more general term, of which they are a species. Nay, we cannot define every species of things, because it happens sometimes that we have not words to express the specific difference. Thus, a scarlet colour is, no doubt, a species of colour ; but how shall we express the specific difference by which scarlet is distinguished from green or blue ? The difference of them is immediately per- ceived by the eye ; but we have not words to express it. These things we are taught by logic. Without having recourse to the prin- ciples of logic, we may easily be satisfied that words cannot be defined, which signify things perfectly simple, and void of all com- position. This observation, I think, was first made by Des Cartes, and afterwards more fully illustrated by Locke.*}* And, however obvious it appears to be, many in- stances may be given of great philosophers who have perplexed [12] and darkened the subjects they have treated, by not knowing, or not attending to it. When men attempt to define things which cannot be defined, their definitions will always be either obscure or false. It was one of the capital defects of Aristotle's phi- losophy, that he pretended to define the simplest things, which neither can be, nor need to be defined — such as time and mo- th n.% Among modern philosophers, I * It is well said by the old logicians, Omnia in- tuttiva notttia est definitio; — that is, a view of the thing itself is its best definition And 'his in inie, both of the objects of sense, and of the objects of self- consciousness. — H. t This is incorrect Des Cartes has little, and I.ocke no title to praise for this observation. It had been made by Aristotle, and alter him by many others; while, subsequent to Des Cartes, and pre- vious to Locke, Pascal and the Port. Royal Logicians, to say nothing of a paper of Leibnitz, in 1R84-, had re- duced it to a matter of commonplace. In this instance, Lncke can, indeed, be proved a borrower. M r Stewart (" Philosophical Kssays," Note A) is wrong in think- ing that, afte< Des Cartes, Lord Stair is the earliest philosopher by whom this logical principle was enounced; for Stair, as a writer, is subsequent to the authors adduced — H. t There is not a lit tic, however, to be said in vin- dicat on of Aristotle's definitions. Leibnitz is not the only modern philosopher who hasapplaudcd iliat of Motion, winch requires, however, some illi s- I tration of the special Mguificance of its terms — H. [12, 13] know none that has abused definition so much as Carolus [Christianus] Wolfius, the famous German philosopher, who, iu a work on the human mind, called " Psycho- logia Empirica," consisting of many hun- dred propositions, fortified by demon- strations, with a proportional accompani- ment of definitions, corollaries, and scholia, has given so many definitions of things which cannot be defined, and so many de- monstrations of things self-evident, that the greatest part of the work consists of tautology, and ringing changes upon words.* There is no subject in which there is more frequent occasion to use words that cannot be logically defined, than in treating of the powers and operations of the mind. The simplest operations of our minds must all be expressed by words of this kind. No man can explain, by a logical definition, what it is to thiiik, to apprehend, to believe, to w 11, todeshe. Every man who under- stands the language, has some notion of the meaning of those words ; and every man who is capable of reflection may, by attend- ing to the operations of his own mind, which are signified by them, form a clear and distinct notion of them ; but they can- not be logically defined. Since, therefore, it is often impossible to define words which we must use on this subject, we must as much as possible use common words, in their common accepta- tion, pointing out their various senses where they are ambiguous ; and, when we are obliged to use words less common, we must endeavour to explain them [13] as well as we can, without affecting to give logical de- finitions, when the nature of the thing does not allow it. The following observations on the mean- ing of certain words are intended to supply, as far as we can, the want of definitions, by preventing ambiguity or obscurity in the use of them. 1. By the mind of a man, we understand that in him which thinks, remembers, rea- sons, wills, f The essence both of body and of mind is unknown to us. We know cer- tain properties of the first, and certain oper- ations of the last, and by these only we can define or describe them. We define body to be that which is extended, solid, move- able, divisible. In like manner, we define mind to be that which thinks. We are con- cious that we think, and that we have a variety of thoughts of different kinds— such as seeing, hearing, remembering, delibe- rating, resolving, loving, hating, and many * This judgment isnot false ; but it is exaggerated — H. t This corresponds to Aristotle's sreord definition of the soul, or i hat a postei ioru Vide supra, p. 203, b,iote-.-H. f ,v > OBAP. I.] EXPLICATION OF WORDS. 221 other kinds of thought — all which we are taught by nature to attribute to one internal principle ; and this principle of thought we call the mind or soul of a man. 2. By the operations' of the mind, we un- derstand every mode of thinking of which we are conscious. It deserves our notice, that the various modes of thinking have always, and in all languages, as far as we know, been called by the name of operations of the mind, or by names of the same Import. To body we ascribe various properties, but not oper- ations, properly so called : it is extended, divisible, moveable, inert ; it continues in any state in which it is put ; every change of its state is the effect of some force im- pressed upon it, and is exactly proportional to the force impressed, and in the precise direction of that force. These are the ge- neral properties of matter, and these are not operations ; on the contrary, they all imply its being a dead, inactive thing, which moves only as it is moved, and acts only by being acted upon.-)- [14] But the mind is, from its very nature, a, living and active being. Everything we know of it implies life and active energy ; and the reason why all its modes of thinking are called its operations, is, that in all, or in most of them, it is not merely passive, as body is, but is really and properly active. In all ages, and in all languages, ancient and modern, the various modes of thinking have been expressed by words of active signification, such as seeing, hearing, reason- ing, willing, and the like. It seems, there- fore, to be the natural judgment of man- kind, that the mind is active in its various ways of thinking : and, for this reason, they are called its operations, and are expressed by active verbs. It may be made a question, What regard is to be paid to this natural judgment ? May it not be a vulgar error ? Philosophers who think so have, no doubt, a right to be heard. But, until it is proved that the mind is not active in thinking, but merely passive, the common language with regard to its operations ought to be used, and ought not to give place to a phraseology invented by philosophers, which implies its being merely passive. 3. The words power and faculty, which are often used in speaking of the mind, need little explication. Every operation supposes a power in the being that oper- rates ; for to suppose anything to operate, which has no power to operate, is mani- festly absurd. But, on the other hand, * Operation, Act, Energy, are nearly convertible terms; and are opposed to Faculty, (of which anon,) as the actual to the potential — H. T " Materiae datum est cogi, sed cogere Menu." Manilius. — H. ("H, I«] there is no absurdity in supposing a being to have power to operate, when it does not operate. Thus I may have power to walk, when I sit ; or to speak, when I am silent. Every operation, therefore, implies power ; but the power does not imply the operation. The faculties of the mind, and its powers, are often used as synonymous expressions. But, as most synonymes have some minute distinction that deserves notice, I apprehend that the word faculty [15] is most properly applied to those powers of the mind which are original and natural, and which make a part of the constitution of the mind. There are other powers, which are acquired by use, exercise, or study, which are not called faculties, but habits. There must be some- thing in the constitution of the mind neces- sary to our being able to acquire habits— and this is commonly called capacity.* 4. We frequently meet with a distinction in writers upon this subject, between things in the mind, and things exlernalio the mind. The powers, faculties, and operations of the mind, are things in the mind. Everything is said to be in the mind, of which the mind is the subject. It is self-evident that there are some things which cannot exist without a subject to which they belong, and of which they are attributes. Thus, colour must be in something coloured ; figure in something figured ; thought can only be in something that thinks ; wisdom and virtue cannot exist but in some being that is wise and virtuous. When, therefore, we speak of things in the mind, we understand by this, things of which the mind is the subject. Excepting the mind itself, and things in the mind, all other things are said to be external. It ought therefore to be remembered, that this dis- tinction between things in the mind and things external, is not meant to signify the place of the things we speak of, but their subject. -f There is a figurative sense in which things are said to be in the mind, which it is suf- ficient barely to mention. We say such a thing was not in my mind ; meaning no more than that I had not the least thought of it. By a figure, we put the-thing for the thought * These terms properly stand in the following re- lations •.—Powers are active and passive, natural and acquired. Powers, natural aid acti ve,.nre railed Faculties : Powers, natural and passive, Capacities or Receptivities : Powers acquired are Habits, and habit is used both in an active and in a pasaive^ense: the Power, again, of acquiring a habit, is called a Disposition. — On the meaning of the term Power, see further, under the first Essay on the Active Powers, chap, iil., p 23— H t Subject and Object are correlative terms. The former is properly id in quo : the latter, id circa quod. Hence, in psychological language, the subject, absolutely, is the mind that knows or thinks — i e., the mind considered as the-sulject of knowledge or thought ; the object, that which is known, or thought about. The adjectives subjective and objective are convenient, if not indispensable, expressions. — H. 222 ON THE INTELLECTUAL POWERS. Qessay i. of it. In this sense external things are in the mind as often as they are the objects of our thought. 5. Thinking is a very general word, which includes all the operations of our minds, and is so well understood as to need no defi- nition.* [16] To perceive, to remember, to be conscious, and to conceive or imagine, are words com- mon to philosophers and to the vulgar. They signify different operations of the mind, which are distinguished in all lan- guages, and by all men that think. I shall endeavour to use them in their most com- mon and proper acceptation, and I think they are hardly capable of strict definition. But, as some philosophers, in treating of the mind, have taken the liberty to use them very improperly, so as to corrupt the Eng- lish language, and to confound things which the common understanding of man- kind hath always led them to distinguish, I shall make someobservations on the mean- ing of them, that may prevent ambiguity or confusion in the use of them. 6. First, We are never said to perceive things, of the existence of which we have not a full conviction. I may conceive or imagine a mountain of gold, or a winged horse ; but no man says that he perceives such a creature of imagination. Thus per- ception'^ distinguished from conception or imagination. Secondly, Perception is ap- plied only to external objects, not to those that are in the mind itself. When I am pained, I do not say that I perceive pain, but that I feel it, or that I am conscious of it. Thus, perception is distinguished from consciousness. Thirdly, The immediate object of perception must be something pre- sent, and not what is past. We may re- member what is past, but do not perceive it. I may say, I perceive such a person has had the small-pox ; but this phrase is figurative, although the figure is so familiar that it is not observed. The meaning of it is, that I perceive the pits in his face, which are certain signs of his having had the small pox. We say we perceive the thing signi- 1 ed, when we only perceive the sign. But when the word perception is used properly, and without any figure, it is never applied to things past. And thus it is distinguished from remembrance. In a word, perception is most properly applied to the evidence which we have of external objects by our senses. But, as this is a [17] very clear and cogent kind of evidence, the word is often applied by ana- logy to the evidence of reason or of testi- • Though /and thinking are used in a more, and in a less, restricted signification. In the former mean, ing they are limited to the discursive energies atone ; in the latter, they are co.extensive with conscious, nesa. — H. T16-181 mony, when it is clear and cogent. The perception of external objects by our senses, is an operation of the mind of a peculiar nature, and ought to have a name appro- priated to it. It has so in all languages. And, in English, I know no word more proper to express this act of the mind than perception. Seeing, hearing, smelling, tasting, and touching or feeling, are words that express the operations proper to each sense ; perceiving expresses that which is common to them all. The observations made on this word would have been unnecessary, if it had not been so much abused in philosophical writings upon the mind ; for, in other writ- ings, it Has no obscurity. Although this abuse is not chargeable on Mr Hume only, yet I think he has carried it to the highest pitch. The first sentence of his " Treatise of Human Nature" runs thus : — " All the perceptions of the human mind resolve themselves into two distinct heads, which I shall call impressions and ideas." He adds, a little after, that, under the name of impressions, he comprehends all our sensations, passions, and emotions. Here we learn that our passions and emotions are perceptions. I believe, no English writer before him ever gave the name of a perception to any passion or emotion. When a man is angry, we must say that he has the perception of anger. When he is . in love, that he has the perception of love. He speaks often of the perceptions of me- mory, and of the perceptions of imagina- tion ; and he might as well speak of the hearing of sight, or of the smelling of touch ; for, surely, hearing is not more different from sight, or smelling from touch, than perceiving is from remembering or imagin- ing.' 7- Consciousness is a word used bv philosophers, to signify that immediate knowledge which we have of our present thoughts and purposes, and, in general, of all the present operations of our minds. Whence we may observe, that conscious- ness is only of things present. To apply consciousness to things past, which some- times [18] is done in popular discourse, is to confound conscieusness with memory ; and all such confusion of words ought to be avoided in philosophical discourse. It is likewise to be observed, that consciousness • In the Cartesian and Locfcian philosophies, the term Perception was used almost convertibly with Consciousness : whatever we could be said to be conscious of, that we could be said to perceive. And there is nothing in the etymology of the word, or in its use by ancient writers, that renders this unexclu- ■ive application of it abusive. In the Leibnitzian philosophy, perception and apperception were dis. tinguished in a peculiar manner— of which again. Reid is right in his own restriction of the term; hut lie is not warranted in blaming Hume for having used it in the wider signification of his predecessors H. CHAP. I.] EXPLICATION OF WORDS. 223 is only of things in the mind, and not of external things. It is improper to say, I am conscious of the table which is before me. I perceive it, I see it ; but do not say I am conscious of it. As that consciousness by which we have a knowledge of the opera- tions of our own minds, is a different power from that by which we perceive external objects, and as these different powers have different names in our language, and, I believe, in all languages, a philosopher ought carefully to preserve this distinction, and never to confound things so different in their nature.* 8. Conceiving, imagining, and appre- hending, are commonly used as synony- mous in our language, and signify the same thing which the logicians call simple appre- hension. This is an operation of the mind different from all those we have mentioned. Whatever we perceive, whatever we re- member, whatever we are conscious of, we have a full persuasion or conviction of its existence. But we may conceive or imagine what has no existence, and what we firmly believe to have no existence. What never had an existence cannot be remembered ; what has no existence at present cannot be the object of perception or of conscious- ness ; but what never had, nor has any existence, may be conceived. Every man knows that it is as easy to conceive a winged horse, or a centaur, as it is to conceive a horse or a man. Let it be observed, therefore, that to conceive, to imagine, to apprehend, when taken in the proper sense, signify an act of the mind which implies no belief or judg- ment at all.-J- It is an act of the mind by which nothing is affirmed or denied, and which, therefore, can neither be true nor false. But there is another and a very different meaning of those words, so common and so well authorized in language that it cannot easily be avoided ; and on that account we ought to be the more on our guard, that we be not misled by the ambiguity. Po- liteness and [19] good-breeding lead men, on most occasions, to express their opinions with modesty, especially when they differ from others whom they ought to respect. Therefore, when we would express our opinion modestly, instead of saying, " This is myopinion," or, " This is my judgment,*' which has the air of dogmaticalness, we say, " I conceiveitto be thus. — I imagine, or ap- prehend it to be thus ;" which is understood as a modest declaration of our judgment- In like manner, when anything is said which wetaketo be impossible, we say, " We can- * Reid's degradation of Consciousness into a special faculty, (in which he seems to follow Hut. cheson, in opposition to other philosophers,) is, in every point of view, obnoxious to every possible ob. lection. See note H — H t Except of its own ideal reality. — H. f 19,20"! not conceive it;" meaning that we cannot believe it. Thus we see that the words conceive, imagine, apprehend, have two meanings, and are used to express two operations of the mind, which ought never to be con- founded. Sometimes they express simple apprehension, which implies no judgment at all ; sometimes they express judgment or opinion. This ambiguity ought to be at- tended to, that we may not impose upuii ourselves or others in the use of tliem. The ambiguity is indeed remedied, in a great measure, by their construction. When they are used to express simple apprehend sion, they are followed by a noun in the accusative case, which signifies the object conceived ; but, when they are used to ex- press opinion or judgment, they are com- monly followed by a verb, in the infinitive mood. " I conceive an Egyptian pyramid.'* This implies no judgment. " I conceive the Egyptian pyramids to be the most an- cient monuments of human art." This implies judgment. When the words are used in the last sense, the thing conceived must be a proposition, because judgment cannot be expressed but by a proposition. When they are used in the first sense, the thing conceived may be no proposition, but a simple term only — as a pyramid, an obe- lisk. Yet it may be observed, that even a proposition may be simply apprehended, without forming any judgment of its truth or falsehood : for it is one thing to conceive the meaning of a proposition ; it is another thing to judge it to be true or false. [20] Although the distinction between simple apprehension, and every degree of assent or judgment, be perfectly evident to every tuan who reflects attentively on what passes in his own mind — although it is very neces- sary, in treating of the powers of the mind, to attend carefully to this distinction— yet, in the affairs of common life, it is seldom necessary to observe it accurately. On this account we shall find, in all common languages, the words which express one oi those operations frequently applied to the other. To think, to suppose, to imagine, to conceive, to apprehend, are the words we use to express simple apprehension ; but they are all frequently used to express judgment. Their ambiguity seldom occa- sions any inconvenience in the common affairs of life, for which language is framed. But it has perplexed philosophers, in treat- ing of the operations of the mind, and will always perplex them, if they do not attend accurately to the different meanings which are put upon those words on different oc- casions. 9. Most of the operations of the mind, from their very nature, must have objects to which they are directed, and about which •J2i ON THE INTELLECTUAL POWERS. £ ESS AST L they are employed. He that perceives, must perceive something ; and that which he perceives is called the object of his per- ception. To perceive, without having any object of perception, is impossible. The mind that perceives, the object perceived, »nd the operation of perceiving that object, are distinct things, and are distinguished in the structure of all languages. In this sentence, " I see, or perceive the moon," / is the person or mind, the active verb see denotes the operation of that mind, and the moon denotes the object. What we have said of perceiving, is equally applicable to most operations of the mind. Such opera- tions are, in all languages, expressed by active transitive verbs ; and we know that, in all languages, such verbs require a thing or person, which is the agent, and a noun following in an oblique case, which is the object. Whence it is evident, that all mankind, both those who have contrived language, and those who use it with under- standing, have distinguished these three things as different — to wit, the operations of the mind, which [21] areexpressed byactive verbs ; the mind itself, which is the nomin- ative to those verbs ; and the object, which is, in the oblique case, governed by them. It would have been unnecessary to ex- plain so obvious a distinction, if some sys- tems of philosophy had not confounded it. Mr Hume's system, in particular, confounds all distinction between the operations of the mind and their "objects. When he speaks of the ideas of memory, the ideas of imagin- ation, and the ideas of sense, it is often im- possible, from the tenor of his discourse, to know whether, by those ideas, he means the operations of the mind, or the objects about which they are employed. And, indeed, according to his system, there is no distinction between the one and the other. A philosopher is, no doubt, entitled to examine even those distinctions that are to be found in the structure of all languages ; and, if he is able to shew that there is no foundation for them in the nature of the things distinguished — if he can point out some prejudice common to mankind which has led them to distinguish things that are not really different — in that case, such a distinction may be imputed to a vulgar error, which ought to be corrected in philo- sophy. But when, in his first setting out, he takes it for granted, without proof, that distinctions found in the structure of all languages, have no foundation in nature, this, surely, is too fastidious a way of treating the common sense of mankind. When we come to be instructed by philo- sophers, we must bring the old light of common sense along with us, and by it judge of the new light which the philo. [21 23~] sopher communicates to us. But when we are required to put out the old light alto- gether, that we may follow the new, we have reason to be on our guard. There may be distinctions that have a real foun- dation, and which may be necessary in philosophy, which are not made in common language, because not necessary in the com- mon business of life. But I believe [22] no instance will be found of a distinction made in all languages, which has not a just found- ation in nature. 10. The word idea* occurs so frequently in modern philosophical writings upon the mind, and is so ambiguous in its meaning, that it is necessary to make some observa- tions upon it. There are chiefly two mean- ings of this word in modern authors — a popular and a philosophical. Firs!, In popular language, idea signi- fies the same thing as conception, appre- hension, notion. To have an idea of any- thing, is to conceive it. To have a distinct idea, is to conceive it distinctly. To have no idea of it, is not to conceive it at all- It was before observed, that conceiving or apprehending has always been considered by all men as an act or operation of the mind, and, on that account, has been ex- pressed in all languages by an active verb. When, therefore, we use the phrase of having ideas, in the popular sense, we ought to attend to this, that it signifies precisely the same thing which we com- monly express by the active verbs, conceiv- ing or apprehending. When the word idea is taken in this po- pular sense, no man can possibly doubt whether he has ideas. For he that doubts must think, and to think is to have ideas. Sometimes, in popular language, a man's ideas signify his opinions. The ideas of Aristotle, or of Epicurus, signify the opinions of these philosophers. What was formerly said of the words imagine, conceive, apprehend, that they are sometimes used to express judgment, is no less true of the word idea. This signification of the word seems indeed more common in the French language than in English. But it is found in this sense in good English authors, and even in Mr Locke. Thus we see, that having ideas, taken in the popular sense, has precisely the same meaning with conceiv- ing, imagining, apprehending, and has like- wise [23] the same ambiguity. It may, there- fore, be doubted, whether the introduction of this word into popular discourse, to signify the operation of conceiving or apprehending, was at all necessary. For, first, We have, as has been shewn, several words which are either originally English, or have been long naturalized, that express the same thing ; • On Ihe history of the term Idea, see Note G H. Chap. i,~\ EXPLICATION OF WORDS. 225 why, therefore, should we adopt a Greek word, in place of these, any more than a French or a German word ? Besides, the words of our own language are less ambi- guous. For the word idea has, for many ages, been used by philosophers as a term of art ; and in the different systems of phi- losophers means very different things. Secondly, According to the philosophi- cal meaning of the word idea, it does not signify that act of the mind which we call thought or conception, but some object of thought. Ideas, according to Mr Locke, (whose very frequent use of this word has probably been the occasion of its being adopted into common language,) " are nothing but the immediate objects of the mind in thinking." But of those objects of thought called ideas, different sects of phi- losophers have given a very different ac- count. Bruckerus, a learned German, wrote a whole book, giving the history of ideas. The most ancient system we have con- cerning ideas, is that which is explained in several dialogues of Plato, and which many ancient, as well as modern writers, have ascribed to Plato, as the inventor. But it is certain that Plato had his doctrine upon this subject, as well as the name idea, from the school of Pythagoras. We have still extant, a tract of Tinueus, the Locrian, a Pythagorean philosopher, concerning the soul of the world, in which we find the sub- stanceof Plato's doctrine concerning ideas.* They were held to be eternal, uncreated, and immutable forms, or models, according to which the Deity made every species of things that exists, of an eternal matter. Those philosophers held, that there are three first principles of all things : Fii si. An eternal matter, of which all things were made ; Secondly, Eternal and immaterial forms, or ideas, according to which they were made; and, [24] Thirdly, An efficient cause, the Deity who made them.-|- The miud of man, in order to its being fitted for the con- templation of these eternal ideas, must un- dergo a certain purification, and be weaned from sensible things. The eternal ideas are the only object of science ; because the ob- jects of sense, being in a perpetual flux, there can be no real knowledge with regard to them. The philosophers of the Alexandrian school, commonly called the latter Plato- nists, made some change upon the system of the ancient Platonists with respect to the eternal ideas. They held them not to be a principle distinct from the Deity, but to be the conceptions of things in the divine un- * The whole series of Pythagorean treatises and fragments in the Doric dialec", in which the doc- trines and phraseology of Plato>and Aristotle are so marvellously anticipated, are now proved to be com- paratively recent forgeries. Of these, the treatise under the name of Timceus, is one. — H. i See aiiove,p.20i, a, note * — H. [24, 25] dcrstanding ; the natures and essences of all things being perfectly known to him from eternity. It ought to be observed that the Pythago- reans, and the Platonists, whether elder or latter, made the eternal'ideas to be objects of science only, and of abstract contempla- tion, not the objects of sense.* And in this, the ancient system of eternal ideas differs from the modern one of Father Ma- lebranche. He held, in common with other modern philosophers, that no external thing is perceived by us immediately, but only by ideas. But he thought that the ideas, by which we perceive an external world, are the ideas of the Deity himself, in whose mind the ideas of all things, past, present, and future, must have been from eternity ; for the Deity being intimately present to our minds at all times, may dis- cover to us as much of his ideas as he sees proper, according to certain established laws of nature ; and in his ideas, as in a mirror, we perceive whatever we do per- ceive of the external world. Thus we have three systems, which main- tain that the ideas which are the imme- diate objects of human knowledge, are eternal and immutable, and existed before the things which they represent. There are other systems, according to which the ideas which are the immediate objects of all our thoughts, are posterior to the things which they represent, and derived from them. We shall [25] give some account of these ; but, as they have gradually sprung out of the ancient Peripatetic system, it is necessary to begin with some account of it. Aristotle taught that all the objects of our thought enter at first by the senses ; and, since the sense cannot receive external material objects themselves, it receives their species — that is, their images or forms, without the matter ; as wax receives the form of the seal without any of the matter of it. These images or forms, impressed upon the senses, are called sensible species, and are the objects only of the sensitive part of the mind ; but, by various internal powers, they are retained, refined, and spiritualized, so as to become objects of memory and imagina- tion, and, at last, of pure intellection. When they are objects of memory and of imagination, they get the nameof phantasms. When, by farther refinement, and being stripped of their particularities, they become objects of science, they are called intelli- gible species : so that every immediate * Reid, in common with ourphilosophers in general, had no knowledge rf the Platonic theory of sensible perception; and yet the gnostic forms, the cognitive reasons of the Platonists, held afar more proximate relation to ideas in the modern acceptation, than the Platonic ideas themselves. These, in fact, as to all that relates to the doctrine of perception and ima- gination, may be thrown wholly nut of account. See below, under p. 11(5. — H. 22f! ON THE INTELLECTUAL POWEKS. [essay i. object, whether of sense, of memory, of imagination, or of reasoning, must he some phantasm or species in the mind itself. * The followers of Aristotle, especially the schoolmen, made great additions to this theory, which the author himself mentions very briefly, and with an appearance of reserve. They entered into large disquisi- tions with regard to the sensible species : what kind of things they are ; how they are sent forth by the object, and enter by the organs of the senses ; how they are preserved and refined by various agents, called internal senses, concerning the num- ber and offices of which they had many controversies. But we shall not enter into a detail of these matters. The reason of giving this brief account of the theory of the Peripatetics, with regard to the immediate objects of our thoughts, is, because the doctrine of modern philoso- phers concerning ideas is built upon it. Mr Locke, who uses this word so very fre- quently, tells us, that he means the same thing by it as is commonly [26] meant by species or phantasm. Gassendi, from whom Locke borrowed more than from any other author, says the same. The words species and phantasm, are terms of art in the Peripa- tetic system, and the meaning of them is to be learned from it.-(- The theory of Democritus and Epicurus, on this subject, was not very unlike to that of the Peripatetics. They held that all bodies continually send forth slender films or spectres from their surface, of such extreme subtilty that they easily penetrate our gross bodies, or enter by the organs of sense, and stamp their image upon the mind. The sensible species of Aristotle were mere forms without matter. The spectres of Epicurus were composed of a very subtile matter. Modern philosophers, as well as the Peri- patetics and Epicureans of old, have con- ceived that external objects cannot be the immediate objects of our thought; that there must be some image of them in the mind itself, in which, as in a mirror, they are seen. And the name vlea, in the philo- sophical sense of it, is given to those inter- nal and immediate objects of our thoughts. The external thing is the remote or mediate object ; but the idea, or image of that object in the mind, is the immediate object, without • This i6 a tolerable account of the doctrine vulgarly attributed to Aristotle.— H. + If by this it be meant thai the terms of specie* and phantasm, as occasionally employed by Gassendi and Locke, are used by them in the common mean- ing attache.*) to them in the Schools, Reid is wrong. Gassendi, no more than Des Cartes, in adopting these terms of the Peripatetics, adopted them in their Peripatetic signification. Both these philoso- pliers are explicit in declaring the contrary ; and what these terms as employed by them denote, they bavc cli arly st .ted. Locke is less precise. — H. which we could have no perception, no re- membrance, no conception of the mediate object. * When, therefore, in common language, we speak of having an idea of anything, we mean no more by that expression, but thinking of it. The vulgar allow that this expression implies a mind that thinks, an act of that mind which we call thinking, and an object about which we think. But, besides these three, the philosopher con- ceives that there is a fourth — to wit, the idea, which is the immediate object. The idea is in the mind itself, and can have no existence but in a mind that thinks ; but the remote or mediate object may be something external, as the sun or moon ; it may be something past or future ; it may be some- thing which never existed. [27] This is the philosophical meaning of the word idea ; and we may observe that this meaning of that word is built upon a philosophical opinion : for, if philosophers had not be- lieved that there are such immediate objects of all our thoughts in the mind, they would never have used the word idea to express them. I shall only add, on this article, that, al- though I may have occasion to use the word idea in this philosophical sense in explaining the opinions of others, I shall have no occa- sion to use it in expressing my own, because I believe ideas, taken in this sense, to be a mere fiction of philosophers. And, in the popular meaning of the word, there is the less occasion to use it, because the English words thought, notion, apprehension, ansv.gr the purpose as well as the Greek word idea; with this advantage, that they are le°s ambiguous. There is, indeed, a mean- ing of the word idea, which I think most agreeable to its use in ancient philosophy, and which I would willingly adopt, if use, the arbiter of language, did permit. But this will come to be explained afterwards- 1 1. The word impression is used by Mr Hume, in speaking of the operations of the mind, almost as often as the word idea is by Mr Locke. What the latter calls ideas, the former divides into two classes ; one of which he calls impressions, the other ideas. I shall make some observations upon Mr Hume's explication of that word, and then consider the proper meaning of it in the English language. " We may divide," (says Mr Hume, " Essays," vol. II., p. 18,-f) " all the percep- tions of the human mind into two classes or species, which are distinguished by their * On Reid's ambiguous employment of the ex- pressions mediate and immediate object, see Note B ; and, on his confusion of the two hypotheses of representation, Note C — H. t " Enquiry concerning Human Understanding," tj 2. The quotation has been filled up by the origi- nal.— H. 26, 2?1 CHAP. I.J EXPLICATION OF WORDS. 227 different degrees of force and vivacity. The less lively and forcible are commonly deno- minated thoughts or ideas. The other species want a name in our language, and in most others ; [I suppose because it was not requisite for any but philosophical pur- poses to rank them under a general term or appellation] Let us, therefore, use a little freedom, and call them impressions ; [employing that word in a sense somewhat different from the usual.] By the term impression, then, I mean all our more lively perceptions, when we hear, or see, or feel, or love, or hate, or desire, or will. [And impressions are distinguished from] ideas [which] are the [28] less lively perceptions, of which we are conscious, when we reflect on any of those sensations or movements above mentioned." This is the explication Mr Hume hath given in his " Essays" of the term impres- sions, when applied to the mind : and his explication of it, in his " Treatise of Human Nature," is to the same purpose. [Vol. I. p. 11.] Disputes about words belong rather to grammarians than to philosophers ; but philosophers ought not to escape censure when they corrupt a language, by using words in a way which the purity of the lan- guage will not admit. I find fault with Mr Hume's phraseology in the words I have quoted — First, Because he gives the name of per- ceptions to every operation of the mind. Love is a perception, hatred a perception ; desire is a perception, will is a perception ; aud, by the same rule, a doubt, a question, a command, is », perception. This is an intolerable abuse of language, which no phi- losopher has authority to introduce.* Secondly, When Mr Hume says, that we may divide all the perceptions of the human mind into two classes or species, which are distinguished by their degrees of force and vivacity, the manner of expression is loose and unphilosophical. To differ in species is one thing; to differ in degree is an- other. Things which differ in degree only must be of the same species. It is a maxim of common sense admitted by all men, that greater and less do not make a change of species. -f The same man may differ in the degree of his force and vivacity, in the morning and at night, in health and in sickness ; but this is so far from making him a different species, that it does not so much as make him a dif- ferent individual. To say, therefore, that two different classes, or species of percep- * Hume did not introduce it The term Percep- tion was so used by Des Cartes and many others ; and, as desires, feelings, &c. exist only as known, so are they all, in a certain sense, cognitions (perceptions.) — H. ■f " Magiset minus non variant spcciem." — K. f28, 29] tions, are distinguished by the degrees ol their force and vivacity, is to confound a difference of decree with a difference of species, which every man of understanding knows how to distinguish.* [29] Thiidly, We may observe, that this author, having given the general name of perception to all the operations of the mind,-)- and distinguished them into two classes or species, which differ only in de- gree of force aud vivacity, tells us, that he gives the name of impressions to all our more lively perceptions— to wit, when v. u hear, or see, or feel, or love, or hate, or desire, or will. There is great confusion in this account of the meaning of the word impression.- When I see, this is an im- pression. But why has not the author told us whether he gives the name of im- pression to the object seen, or to that act of my mind by which I see ij ? When I see the full moon, the full moon is one thing, my perceiving it is another thing. Which of these two things does he call an impres- sion ? We axe left to guess this ; nor does all that this author writes about impressions clear this point. Everything he says tends to darken it, and to Lead us to think that the full moon which I see, and my seeing it, are not two things, but one and the same thing. J The same observation may be applied to every other instance the author gives to illustrate the meaning of the word impres- sion. " When we hear, when we feel, when we love, when we hate, when we de- sire, when we will." In all these acts of the mind there must be an object, which is heard, or felt, or loved, or hated, or desired, or willed. Thus, for instance, I love my country. This, says Mr Hume, is an im- pression. But what is the impression f Is it my country, or is it the affection I bear to it ? I ask the philosopher this question ; but I find no answer to it. And when I read all • This objection reaches far more extensively than to Hume ; in fact, to all who do not allow an imme- diate knowledge or consciousness of the r.on-ego in perception. Where are the philosophers who 10?— Aristotle and Hobbes call imagination a dying sense ; and Des Cartes is equally explicit. — H. t As others previously had done.— H. j This objection is easily answered. The thing, (Hume would say,) as unknown, as unperceived, as beyund the sphere of my consciousness, is to me as zero ; to that, therefore, I could not refer, Asper- ceived, as known, it must be within the sphere oj my consciousness; but, as philosopher s concur irr main- taining that i can only be conscious of my mind and its contents, the object, as perceived, mlM be eit her a mode of, or something contained within my mind, and i o that intemalobject, as perceived, I give the name of impression. — Nor can the act of perception (he would add) be really distinguished from the oh. ject perceived. Both are only relatives, mutually constituent of the same indivisible relation ofknow- ledge ; and to that relation and these relatives I give the name of impression, precisely as, in different points of view, the term perception is applied to the mind perceiving, to the object perceived, and to the act of which these are the inseparable constituents. — I his likewise has reference to what follows. — H. 228 ON- THE INTELLECTUAL POWERS. [essay I- that he has written on this subject, I find this word impression sometimes used to sig- nify an operation of the mind, sometimes the object of the operation ; but, for the most part, it is a vague and indetermined word that signifies both. I know not whether it may be considered as an apology for such abuse of words, in an author who understood the language so well, and used it with so great propriety in writ- ing on other subjects, [30] that Mr Hume's system, with regard to the mind, required a language of a different structure from the common : or, if expressed in plain English, would have been too shocking to the com- mon sense of mankind. To give an instance or two of this. If a man receives a present on which he puts a high value, if he see and handle it, and put it in his pocket, this, says Mr Hume, is an impression. If the man only dream that he received such a present, this is an idea. Wherein lies the difference between this impression and this idea— between the dream and the reality ? They are different classes or species, says Mr Hume : so far all men will agree with him. Buthe adds, that they are distinguished only by different degrees of force and viva- city. Here he insinuates a tenet of his own, in contradiction to the commonsense of mankind. Common sense convinces every man, that a lively dream is no nearer to a reality than a faint one ; and that, if a man should dream that he had all the wealth of Croesus, it would not put one farthing in his pocket. It is impossible to fabricate ar- guments against such undeniable principles, without confounding the meaning of words. In like manner, if a man would persuade me that the moon which I see, and my see- ing it, are not two things, but one and the same thing, he will answer his purpose less by arguing this point in plain English, than by confounding the two under one name — such as that of an impression. For such is the power of words, that, if we can be brought to the habit of calling two things that are connected by the same name, we are the more easily led to believe them to be one and the same thing. Let us next consider the proper meaning of the word impression* in English, that we may see how far it is fit to express either the operations of the mind or their objects. When a figure is stamped upon a body by pressure, that figure is called an impression, as the impression of a seal on wax, of [31 ] printing-types, or of a copperplate on paper This seems now to be the literal sense of the word ; the effect borrowing its name from the cause. But, by metaphor or ana- logy, like most other words, its meaning is extended, so as to signify any change pro- » See below, under 1 p. 338.— H. duced in a body by the operation of some external cause. A blow of the hand makes no impression on a stone wall ; but a bat- tery of cannon may. The moon raises a tide in the ocean, but makes no impression on rivers and lakes. When we speak of making an impression on the mind, the word is carried still farther from its literal meaning ; use, however, which is the arbiter of language, authorizes this application of it — as when we say that admonition and reproof make little impres- sion on those who are confirmed in bad habits. The same discourse delivered in one way makes a strong impression on the hearers ; delivered in another way, it makes no impression at all. It may be observed that, in such ex- amples, an impression made on the mind always implies some change of purpose or will ; some new habit produced, or some former habit weakened ; some passion raised or allayed. When such changes are pro- duced by persuasion, example, or any ex- ternal cause, we say that such causes make an impression upon the mind; but, when things are seen, or heard, or apprehended, without producing any passion or emotion, we say that they make no impression. In the most extensive sense, an impres- sion is a change produced in some passive subject by the operation of an external cause. If we suppose an active being to produce any change in itself by its own active power, this is never called an im- pression. It is the act or operation of the being itself, not an impression upon it. From this it appears, that to give the name of an impression to any effect produced in the mind, is to suppose that the mind does not act at all in the production of that effect. If seeing, hearing, desiring, willing, be operations of the mind, they cannot be im- pressions. If [32] they he impressions, they cannot be operations of the mind. In the structure of all languages, they are con- sidered as acts or operations of the mind it- self, and the names given them imply this. To call them impressions, therefore, is to trespass against the structure, not of a par- ticular language only, but of all languages.* If the word impression be an improper word to signify the operations of the mind, it is at least as improper to signify their objects ; for would any man be thought to speak with propriety, who should say that the sun is an impression, that the earth and the sea are impressions ? It is commonly believed, and taken for granted, that every language, if it be suffi- ciently copious in words, is equally fit to express all opinions, whether they be true • But see Scaligcr, •• De Stabtilitate," Exero. 298. \ 1. [30-32/ >JHAP. I.] EXPLICATION OF WORDS. 2W.) or false. I apprehend, however, that there is an exception to this general rule, which deserves our notice. There are certain common opinions of mankind, upon which the structure and grammar of all languages are founded. While these opinions are common to all men, there will be a great similarity in all languages that are to be found on the face of the earth. Such a similarity there really is ; for we find in all languages the same parts of speech, the distinction of nouns and verbs, the distinc- tion of nouns into adjective and substan- tive, of verbs into active and passive. In verbs we find like tenses, moods, persons, and numbers. \There are general rules of grammar, the same in all languages. This similarity of structure in all languages, shews an uniformity among men in those opinions upon which the structure of lan- guage is founded. If, for instance, we should suppose that there was a nation who believed that the things which we call attributes might exist without a subject, there would be in their language no distinction between adjectives and substantives, nor would it be a rule with them that an adjective has no mean- ing, unless when joined to a substantive. If there was any nation who did not dis- tinguish between [33] actingand being acted upon, there would in their language be no distinction between active and passive verbs ; nor would it be a rule that the active verb must have an agent in the nominative case, but that, in the passive verb, the agent must be in an oblique case. Thestructure of all languages is grounded upon common notions, which Mr Hume's philosophy opposes, and endeavours to overturn. This, no doubt, led him to warp the common language into a conformity with his principles ; but we ought not to imitate him in this, until we are satisfied that his principles are built on a solid foundation. 12. Sensation is a name given by philo- sophers to an act of mind, which may be distinguished from all others by this, that it hath no object distinct from the act itself." Pain of every kiud is an uneasy sensation. When I am pained, I cannot say that the pain I feel is one thing, and that my feeling it is another thing. They are one and the same thing, and cannot be disjoined, even in imagination. Pain, when it is not felt, has no existence. It can be neither greater nor less in degree or duration, nor anything else in kind than it is felt to be. It cannot exist by itself, nor in any subject but in a sentient being. No quality of an inanimate * But sensation, in the language of philosophers, has been generally employed to denote the whole pro- cess of sensitive.cognition, including both peiccpiion j riper and xrnsation proper. On this distinction, lee below, Essay II., ch. xvi., and Note D.* H. [33 31] insentient being can have the least resem- blance to it. What we have said of pain may be applied to every other sensation. Some of them are agreeable, others uneasy, in various degrees. These being objects of desire or aversion, have some attention given to them ; but many are indifferent, and so little attended to that they have no name in any language. Most operations of the mind that have names in common language, are complex in their nature, and made up of various ingredients, or more simple acts ; which, though conjoined in our constitution, must be disjoined by abstraction, in order to our having a distinct and scientific notion of the complex operation. [34] In such operations, sensation, for the most part, makes an in- gredient. Those who do not attend to the complex nature of such operations, are apt to resolve them into some one of the simple acts of which they are compounded, over- looking the others. And from this cause many disputes have been raised, and many errors have been occasioned with regard to the nature of such operations. The perception of external objects is accompanied with some sensation corre- sponding to the object perceived, and such sensations have, in many cases, in all lan- guages, the same name with the external object which they always accompany. The difficulty of disjoining, by abstraction, things thus constantly conjoined in the -course of nature, and things which have one and the same name in all languages, has likewise been frequently an occasion of errors in the philosophy of the mind. To avoid such errors, nothing is of more importance than to have a distinct notion of that simple act of the mind which we call sensation, and which we have endeavoured to describe. By this means, we shall find it more easy to distinguish it from every external object that it accompanies, and from every other act of the mind that may be conjoined with it. For this purpose, it is likewise of import- ance that the name of sensation should, in philosophical writings, be appropriated to signify this simple act of the mind, without including anything more in its signification, or being applied to other purposes I shall add an observation concerning the word fueling. This word has two meanings. First, it signifies the perceptions we have of external objects, by the sense of touch. When we speak of feeling a body to be hard or soft, rough or smooth, hot or cold, to feel these things is to perceive them by touch. They are external things, and that act of the mind by which we feel them is easily distinguished from the objects felt. Secondly, the word feeling is used to signify the same thinff as sensation, which we have 230 ON THE INTELLECTUAL POWERS. £essay i. just now explained ; and, in this sense, it has no object; the feeling and the thing felt are one and the same. [35] Perhaps betwixt feeling, taken in this last sense, and sensation, there may be this small difference, that sensation is most com- monly used to signify those feelings which we have by our external senses and bodily appetites, and all our bodily pains and pleasures. But there are feelings of a nobler nature accompanying our affections, our moral judgments, and our determina- tions in matters of taste, to which the word sensation is less properly applied. I have premised these observations on the meaning of certain words that frequently occur in treating of this subject, for two reasons : First, That I may be the better understood when I use them; and, Secondly, That those who would make any progress in this branch of science, may accustom themselves to attend very carefully to the meaning of words that are used in it. They may be assured of this, that the ambiguity of words, and the vague and improper appli- cation of them, have thrown more darkness upon this subject than the subtilty and intricacy of things. When we use common words, we ought to use them in the sense in which they are most commonly used by the best and purest writers in the language ; and, when we have occasion to enlarge or restrict the meaning of a common word, or give it more precision than it has in common language, the reader ought to have warning of this, otherwise we shall impose upon ourselves and upon him. A very respectable writer has given a good example of this kind, by explaining, in an Appendix to his " Elements of Criti- cism," the terms he has occasion to use. In that Appendix, most of the words are explained on which I have been making observations ; and the explication I have given, I think, agrees, for the most part, with his. Other words that need explication, shall be explained as they occur. [36] CHAPTER II. PRINCIPLES TAKEN FOE GRANTED. As there are words common to philosophers and to the vulgar, which need no explica- tion, so there are principles common to both, which need no proof, and which do not admit of direct proof. One who applies to any branch of science, must be come to years of understanding, and, consequently, must have exercised his rrason, and the other powers of his mind, in various ways. Hu must have formed \ arious opinions and principles, by which he conducts himself in the affairs of life. Of those principles, some are common to all men, being evident in themselves, and so necessary in the conduct of life that a man cannot live and act according to the rules of common prudence without them. All men that have common understand- ing, agree in such principles ; and consider a man as lunatic or destitute of common sense, who denies or calls them in question. Thus, if any man were found of so strange a turn as not to believe his own eyes, to put no trust in his senses, nor have the least regard to their testimony, would any man think it worth while to reason gravely with such a person, and, by argument, to convince him of his error ? Surely no wise man would. For, before men can reason together, they must agree in first principles ; and it is impossible to reason with a man who has no principles in common with you. There are, therefore, common principles, which are the foundation of all reasoning and of all science. Such common principles seldom admit of direct proof, nor do they need'it. Men need not to be taught them ; for they are such as all men of [37] com- mon understanding know ; or such, at least, as they give a ready assent to, as soon as they are proposed and understood. Such principles, when we have occasion to use them in science, are called axioms. And, although it be not absolutely neces- sary, yet it may be of great use, to point out the principles or axioms on which a science is grounded. Thus, mathematicians, before they prove any of the propositions of mathematics, lay down certain axioms, or common princi- ples, upon which they build their reason- ings. And although those axioms be truths which every man knew before — such as, That the whole is greater than a part, That equal quantities added to equal quantities make equal sums ; yet, when we see no- thing assumed in the proof of mathematical propositions, but such self-evident axioms, the propositions appear more certain, and leave no room for doubt or dispute. In all other sciences, as well as in mathe- . matics, it will be found that there are a few common principles, upon which all the reasonings in that science are grounded, and into which they may be resolved. If these were pointed out and considered, we should be better aide to judge what stress may be laid upon the conclusions in that science. If the principles be certain, the conclusions justly drawn from them must be certain. If the principles be only probable, the con- clusions can only be probable. If the prin- ciples be false, dubious, or obscure, the superstructure that is built, upon them must partake of the weakness of the found- ation. [35-57] OIIAP. II. PRINCIPLES TAKEN FOR GRANTED. 231 Sir Isaac- Newton, the greatest of na- tural philosophers, has given an example well worthy of imitation, by laying down the common principles or axioms, on which the reasonings in natural philosophy are built. Before this was done, the reason- ings of philosophers in that science were as vague and uncertain as they are in most others. Nothing was fixed ; all was dispute and controversy; [38] but, by this happy expedient, a solid foundation is laid iu that science, and a noble super- structure is raised upon it, about which there is now no more dispute or con- troversy among men of knowledge, than there is about the conclusions of mathe- matics. It may, however be observed, that the first principles of natural philosophy are of a quite different nature from mathematical axioms : they have not the same kind of evidence, nor are they necessary truths, as mathematical axioms are. They are such as these : That similar effects proceed from the same or similar causes ; That we ought to admit of no other causes of natural effects, but such as are true, and sufficient to ac- count for the effects. These are principles which, though they ha ve not the same kind of evidence that mathematical axioms have ; yet have such evidence that every man of common understanding readily assents to them, and finds it absolutely necessary to conduct his actions and opinions by them, iii the ordinary affairs of life. Though it has not been usual, yet I con- ceive it may be useful, to point out some of those things which I shall take for granted, as first principles, in treating of the mind and its faculties. There is the more oc- casion for this ; because very ingenious men, such as Des Cartes, Malebranche, Arnauld, Locke, and many others, have lost much labour, by not distinguishing things which require proof, from things which, though they may admit of illustra- tr.ition, yet, being self-evident, do not admit of proof. When men attempt to deduce such self-evident principles from others more evident, they always fall into incon- clusive reasoning : and the consequence of th : s has been, that others, such as Berkeley and Hume, finding the arguments brought to prove such first principles to be weak and inconclusive, have been tempted first to doubt of them, and afterwards to deny them. It is so irksome to reason with those who deny first principles, that wise men com- monly decline it. Yet it is not impossible, that [39] what is only a vulgar prejudice may be mistaken for a first principle. Nor is it impossible that what is really a first principle may, by the enchantment of words, have such a mist th-own about it, as t • f3tf 4.01 hide its evidence, and to make a man of candour doubt of it. Such cases happen more frequently, perhaps, in this science than in any other ; but they are not alto- gether without remedy. There are ways by which the evidence of first principles may be made more apparent when they are brought into dispute ; but they require to be handled in a way peculiar to themselves. Their evidence is not demonstrative, but intuitive. They require not proof, but to be placed in a proper point of view. This will be shewn more fully in its proper place, and applied to those very principles which we now assume. In the meantime, when they are proposed as first principles, the reader is put on his guard, and warned to consider whether they have a just claim to that character. 1. First, then, I shall take it for granted, that I think, that I remember, that I tea- son, and, in general, that I really perform all those operations of mind of which I am conscious. The operations of our minds are attended with consciousness ; and this consciousness is the evidence, the only evidence, which we have or can have of their existence. If a man should take it into his head to think or to say that his consciousness may de- ceive him, and to require proof that it can- not, I know of no proof that can be given him ; he must be left to himself, as a man that denies first principles, without which there can be no reasoning. Every man finds himself under a necessity of believing what consciousness testifies, and everything that hath this testimony is to be taken as a first principle. • 2. As by consciousness we know cer- tainly the existence of our present thoughts and passions ; so we know the past by re- membrance. -f- And, when they are re- cent, and the remembrance of them fresh, [40] the knowledge of them, from such distinct remembrance, is, in its certainty and evidence, next to that of conscious- ness. 3. But it is to be observed that we are conscious of many things to which we give little or no attention. We can hardly at- tend to several things at the same time ; and our attention is commonly employed about that which is the object of our thought, and rarely about the thought it- self. Thus, when a man is angry, his • To doubt that we are conscious of this or that, is impossible. For the doubt must at least postulate itself ; but the doubt is only a datum of conscious- ness ; therefore, in postulating its own reality, it ad- mits the truth of consciousness, and consequently annihilates itself See below, p. 579 On Con. Bciousness, in the history of psychology, see Note H. — H. + Remembrance cannot be taken out of Cun- sciuusnrss- SeeNott'H.— H 232 ON THE INTELLECTUAL TOWERS. [_ESSAY t. attention is turned to the injury done him, or the injurious person ; and he gives very little attention to the passion of anger, al- though he is conscious of it. It is in our power, however, when we come to the years of understanding, to give attention to our own thoughts and passions, and the va- rious operations of our minds. And, when we make these the objects of our atten- tion, either while they are present or when they are recent and fresh in our me- mory, this act of the mind is called reflec- tion. We take it for granted, therefore, that, by attentive reflection, a man may have a clear and certain knowledge of the opera- tions of his own mind ; a knowledge no less clear and certain than that which he has of an external object when it is set before his eyes. This reflection is a kind of intuition, it gives a like conviction with regard to in- ternal objects, or things in the mind, as the faculty of seeing gives with regard to objects of sight. A man must, therefore, be convinced beyond possibility of doubt, of everything with regard to the opera- tions of his own mind, which he clearly and distinctly discerns by attentive reflec- tion. * 4. I take it for granted that all the thoughts I am conscious of, or remember, are the thoughts of one and the same • thinking principle, which I call myself, or my mind. Every man has an immediate and irresistible conviction, not only of his present existence, but of his continued existence and identity, as far back as he can remember. If any man should think fit to demand [41] a proof that the thoughts he is successively conscious of, belong to one and the same thinking principle — if he should demand a proof that he is the same person to-day as he was yesterday, or a year ago — I know no proof that can be given him : he must be left to himself, either as a man that is lunatic, or as one who denies first principles, and is not to be reasoned with. Every man of a sound mind, finds him- self under a necessity of believing his own identity, and continued existence. The conviction of this" is immediate and irresist- able ; and, if he should lose this conviction, it would be a certain proof of insanity, which is not to be remedied by reasoning. 5. I take it for granted, that there are some things which cannot exist by them- selves, but must be in something else to which they belong,asqualities, or attributes. Thus, motion cannot exist, but in some- * See ijtfra, pp. 60, 105, 581 , where a timilar, and pp 32i, 516, where a different extension is given to Reflection. On Attention and Reflection, in the history of psychology, see Note 1- — H. thing that is moved. And to suppose that there can be motion while everything is at rest, is a gross and palpable absurdity. In like manner, hardness and softness, sweet- ness and bitterness, are things which cannot exist by themselves ; they are qualities of something which is hard or soft, sweet or bitter. That thing, whatever it be, of which they are qualities, is called their sub- ject; and such qualities necessarily suppose a subject. Things which may exist by themselves, and do not necessarily suppose the exist- ence of anything else, are called substances ; and, with relation to the qualities or attri- butes that belong to them, they are called the subjects of such qualities or attributes. All the things which we immediately per- ceive by our senses, and all the things we are conscious of, are things which must be in something else, as their subject. Thus, by my senses, I perceive figure, colour, hardness, softness, motion, resistance, and such[42] likethings. Butthesearequahties, and must necessarily be in something that is figured, coloured, hard or soft, that moves, or resists. It is not to these qua- lities, but to that which is the subject of them, that we give the name of body. If any man should think fit to deny that these things are qualities, or that they require any subject, I leave him to enjoy his opinion as a man who denies first principles, and is not fit to be reasoned with. If he has common understanding, he will find that he cannot converse half an hour without say- ing things which imply the contrary of what he professes to believe. In like manner, the things I am conscious of, such as thought, reasoning, desire, ne- cessarily suppose something that thinks, that reasons, that desires. We do not give the name of mind to thought, reason, or desire ; but to that being which thinks, which reasons, and which desires. That every act or operation, therefore, supposes an agent, that every quality sup- poses a subject, are things which I do not attempt to prove, but take for granted. Every man of common understanding dis- cerns this immediately, and cannot enter- tain the least doubt of it. In all languages, we find certain words which, by gramma- rians, are called adjectives. Such words denote attributes, and every adjective must have a substantive to which it belongs — that is, every attribute must have a subject. In all languages, we find active verbs which denote some action or operation ; and it is a fundamental rule in the grammar of all languages, that such a verb supposes a per- son— that is, in other words, that every action must have an agent. We take it, therefore, as a first principle, that goodness, wisdom, and virtue, can only be in some [41, 42] ...] PRINCIPLES TAKEN FOR GRANTED. 233 being that is good, wise, and virtuous ; that thinking supposes a being that thinks ; and that every operation we are conscious of supposes an agent that operates, which we call mind. 6. I take it for granted, that, in most operations of the mind, there [43] must be an object distinct from the operation itself. I cannot see, without seeing something. To see without having any object of sight is absurd. I cannot remember, without re- membering something. The thing remem- bered is past, while the remembrance of it is present ; and, therefore, the operation and the object of it must be distinct things. The operations of our mind are denoted, in all languages, by active transitive verbs, which, from their construction in grammar, require not only a person or agent, but likewise an object of the operation. Thus, the verb know, denotes an operation of mind. From the general structure of lan- guage, this verb requires a person — I know, you know, or he knows ; but it requires no less a noun in the accusative case, denoting the thing known ; for he that knows must know something ; and, to know, without having any object of knowledge, is an ab- surdity too gross to admit of reasoning * 7. We ought likewise to take for granted, as first principles, things wherein we find an universal agreement, among the learned and unlearned, in the different nations and ages of the world. -j- A consent of ages and nations, of the learned and vulgar, ought, at least, to have great authority, unless we can shew some prejudice as universal as that consent is, which might be the cause of it. Truth is one, but error is infinite. There are many truths so obvious to the human faculties, that it may be ex- pected that men should universally agree in them. And this is actually found to be the case with regard to many truths, against which we find no dissent, unless perhaps that of a few sceptical philosophers, who may justly be suspected, in such cases, to differ from the rest of mankind, through pride, obstinacy, or some favourite passion. Where there is such universal consent in things not deep nor intricate, but which lie, as it were, on the surface, there is the greatest presumption that can be, that it is the natural result of the human faculties ; and it must have great authority with every sober [44] mind that loves truth. Major eitim pars eo fere deferri solei quo a natura deducitur. — Cic. de Off. I. 41. Perhaps it may be thought that it is impossible to collect the opinions of all men upon any point whatsoever ; and, there- fore, that this maxim can be of no use. But there are many cases wherein it is » See Note B H. T43-451 + See Note A.— H. otherwise. Who can doubt, for instance, whether mankind have, in all ages, believed the existence of a material world, and that those things which they see and handle are real, and not mere illusions and appari- tions ? Who can doubt whether mankind have universally believed that everything that begins to exist, and every change that happens in nature, must have a cause ? Who can doubt whether mankind have been universally persuaded that there is a right and a wrong in human conduct ? — some things which, in certain circumstan- ces, they ought to do, and other things which they ought not to do ? The univers- ality of these opinions, and of many such that might be named, is sufficiently evi- dent, from the whole tenor of men's con- duct, as far as our acquaintance reaches, and from the records of history, in all ages and nations, that are transmitted to us. There are other opinions that appear to be universal, from what is common in the structure of all languages, ancient and mo- dern, polished and barbarous. Language is the express image and picture of human thoughts ; and, from the picture, we mayoften draw very certain conclusions with regard to the original. We find in all languages the same parts of speech — nouns substantive and adjective, verbs active and passive, varied according to the tenses of past, pre- sent, and future ; we find adverbs, preposi- tions, and conjunctions. There are general rules of syntax common to all languages. This uniformity in the structure of lan- guage shews a certain degree of uniformity in those notions upon which the structure of language is grounded. We find, in the structure of all lan- guages, the distinction of [45] acting and being acted upon, the distinction of action and agent, of quality and subject, and many others of the like kind ; whicl) shews that these distinctions are founded in the uni- versal sense of mankind. We shall have frequent occasion to argue from the sense of mankind expressed in the structure of language ; and therefore it was proper here to take notice of the force of argu- ments drawn from this topic. 8. I need hardly say that I shall also take for granted such facts as are attested to the conviction of all sober and reasonable men, either by our senses, by memory, or by human testimony. Although some wri- ters on this subject have disputed the authority of the senses, of memory, and of every human faculty, yet we find that such persons, in the conduct of life, in pursuing their ends, or in avoiding dangers, pay the same regard to the authority of their senses and other faculties, as the rest of mankind. By this they give us just ground to doubt of 231 ON THE INTELLECTUAL POWERS. [essat I. their candour in their professions of scep- ticism. This, indeed, has always been the fate of the few that have professed scepticism, that, when they have done what they can to discredit their senses, they find themselves, after all, under a necessity of trusting to 1 hem. Mr Hume has been so candid as to acknowledge this ; and it is no less true of those who have not shewn the same can- dour ; for I never heard that any sceptic run his head against a post, or stepped into a kennel, because he did not believe his eyes. Upon the whole, I acknowledge that we ought to be cautious that we do not adopt opinions as first principles which are not entitled to that character. But there is surely the least danger of men's being im- posed upon in this way, when such prin- ciples openly lay claim to the character, and are thereby fairly exposed to the examina- tion of those who may dispute their au- thority. We do not pretend that those things that are laid down as first principles may not be examined, and that we ought not to [46] have our ears open to what may be pleaded against their being admit- ted as such. Let us deal with them as an upright judge does with a witness who has a fair character. He pays a regard to the testimony of such a witness while his cha- racter is unimpeached ; but, if it can be shewn that he is suborned, or that he is influenced by malice or partial favour, his testimony loses all its credit, and is justly rejected. CHAPTER III. OF HYPOTHESES. Every branch of human knowledge hath its proper principles, its proper foundation and method of reasoning ; and, if we en- deavour to build it upon any other found- ation, it will never stand firm and stable. Thus, the historian builds upon testimony, and rarely indulges conjecture ; the anti- quarian mixes conjecture with testimony, and the former often makes the larger ingredient ; the mathematician pays not the least regard either to testimony or conjec- ture, hut deduces everything, by demon- strative reasoning, from his definitions and axioms. Indeed, whatever is built upon conjecture, is improperly called science ; for conjecture may beget opinion, but can- not produce knowledge. Natural philoso- phy must be built upon the phenomena of the material system, discovered by observ- ation and experiment. When men first began to philosophize — that is, to carry their thoughts beyond the objects of sense, and to inquire into the causes of things, and the secret operations of nature — it was very natural for them to indulge conjecture ; nor was it to be ex- pected that, in many ages, they should dis- cover the proper and scientific way of pro- ceeding in philosophical disquisitions. Ac- cordingly, we find that the most ancient systems in every branch of philosophy were nothing but the conjectures of men famous for their wisdom, whose fame gave author- ity to their opinions. Thus, in early ages, [47] wise men conjectured that this earth is a vast plain, surrounded on all hands by a boundless ocean ; that, from this ocean , the sun, moon, and stars emerge at their rising, and plunge into it again at their setting. With regard to the mind, men in their rudest state are apt to conjecture that the principle of life in a man is his breath ; be- cause the most obvious distinction between a living and a dead man is, that the one breathes, and the other does not. To this it is owing that, in ancient languages, the word which denotes the soul, is that which properly signifies breath or air. As men advance in knowledge, their first conjectures appear silly and childish, and give place to others, which tally better with later observations and discoveries. Thus one system of philosophy succeeds another, . without any claim to superior merit, but this — that it is a more ingenious system of conjectures, and accounts better for com- mon appearances. To omit many ancient systems of this kind, Des Cartes, about the middle of the last century, dissatisfied with the materia prima, the substantial forms, and the occult qualities of the Peripatetics, conjectured boldly, that the heavenly bodies of our sys- tem are carried round by a vortex or whirl- pool of subtile matter, just as straws and chaff are carried round in a tub of water. He conjectured, that the soul is seated in a small gland in the brain, called the pineal gland ; that there, as in her chamber of presence, she receives intelligence of every- thing that affects the senses, by means of a subtile fluid contained in the nerves, called the animal spirits ; and that she dispatches these animal spirits, as her messengers, to put in motion the several muscles of the body, as there is occasion.* By such con- * It is not, however, to be supposed that Des Cartes allowed the soul to be seated by local presence in any part of the body ; lor the smalle-t point of body is still extei ded, and mind is abso'utely simple and in- capable of occupying'place. The | ineal gland, in the Cartesian doctrine, is only analogically called the scat of the soul, inasmuch as this is viewed as the cen- tral point of the corporeal organism ; but while through this point the mind and body are mutually, connected, that connection is not one of a mere physical dependence, as they do not operate on each bv direct and natural causation.— H. [Ki, 17] CHAP. III.] OF HYPOTHESES. 235 jectures as these, Dcs Cartes could account for every phenomenon in nature, in such a plausible manner as gave satisfaction to a great part of the learned world for more than half a century. [48] Such conjectures in philosophical matters have commonly got the name of hypotheses, or theories' And the invention of a hypo- thesis, founded on some slight probabilities, which accounts for many appearances of nature, has been considered as the highest attainment of a philosopher. If the hypo- thesis hangs well together, is embellished by a lively imagination, and serves to ac- count for common appearances, it is con- sidered by many as having all the qualities that should recommend it to our belief, and all that ought to be required in a philo- sophical system. There is such proneness in men of genius to invent hypotheses, and in others to acquiesce in them, as the utmost which the human faculties can atlain in philosophy, that it is of the last consequence to the pro- gress of real knowledge, that men should have a clear and distinct understanding of the nature of hypotheses in philosophy, and of the regard that is due to them. Although some conjectures may have a considerable degree of probability, yet it is evidently in the nature of conjecture to be uncertain. In every case the assent ought to be proportioned to the evidence ; for to believe firmly what has but a small degree of probability, is a manifest abuse of our understanding. Now, though we may, in mnny cases, form very "probable conjectures concerning the works of men, every conjec- ture we can form with regard to the works of God has as little probability as the con- jectures of a child with regard to the works of a man. The wisdom of God exceeds that of the wisest man, more than his wisdom exceeds that of a child. If a child were to conjec- ture how an army is to be formed in the day of battle — how a city is to be fortified, or a state governed — what chance has he to guess right ? As little chance has the wisest man when he pretends to conjecture how the planets move in their courses, how the sea ebbs and flows, and how our minds act upon our bodies. [49] If a thousand of the greatest wits that ever the world produced were, without any previous knowledge in anatomy, to sit down and contrive how, and by what internal organs, the various functions of the human body are carried on, how the blood is made to circulate and the limbs to move, they would not, in a thousand years, hit upon any- thing like the truth. Of all the discoveries that have been ["48 -50] See above, note *, p. 97, b. — H. made concerning the inward structure of the human body, never one was made by conjecture. Accurate observations of ana- tomists have brought to light innumerable artifices of Nature in the contrivance of this machine of the human body, which we can- not but admire as excellently adapted to their several purposes. But the most saga- cious physiologist never dreamed of them till they were discovered. On the other hand, innumerable conjectures, formed in different ages, with regard to the structure of the body, have been confuted by obser- vation, and none ever confirmed. What we have said of the internal struc- ture of the human body, may be said, with justice, of every other part of the works of God, wherein any real discovery has been made. Such discoveries have always been made by patient observation, by accurate experiments, or by conclusions drawn by strict reasoning from observations and ex- periments ; and such discoveries have always tended to refute, but not to confirm, the theories and hypotheses which ingenious men have invented. As this is a fact confirmed by the history of philosophy in all past ages, it ought to have taught men, long ago, to treat with just contempt hypotheses in every branch of philosophy, and to despair of ever ad- vancing real knowledge in that way. The Indian philosopher, being at a loss to know how the earth was supported, invented the hypothesis of a huge elephant; and this elephant he supposed to stand upon the back of a huge tortoise. This hypothesis, however ridiculous it appears to us, might seem very reasonable [50] toother Indians, who knew no more than the inventor of it ; and the same will be the fate of all hypo- theses invented by men to account for the works of God. They may have a decent and plausible appearance to those who are not more knowing than the inventor ; but, when men come to be more enlightened, they will always appear ridiculous and childish. This has been the case with regard to hypotheses that have been revered by the most enlightened part of mankind for hun- dreds of years ; and it will always be the case to the end of the world. For, until the wisdom of men bear some proportion to the wisdom of God, their attempts to find out the structure of his works, by the force of their wit and genius, will be vain. The finest productions of human art are immensely short of the meanest works of Nature. The nicest artist cannot make a feather or the leaf of a tree. Human workmanship will never bear a comparison with divine. Conjectures and hypotheses are the invention and the workmanship of men, and must bear proportion to the capa- 236 OX THE INTELLECTUAL POWERS. [essay city and skill of the inventor; and, there- fore, will always be very unlike to the works of God, which it is the business of philosophy to discover. The world has been so long befooled by hypotheses in all parts of philosophy, that it is of the utmost consequence to every man who would make any progress in real knowledge, to treat them with just con- tempt, as the reveries of vain and fanciful men, whose pride makes them conceive them- selves able to unfold the mysteries of nature by the force of their genius. A learned man, in an epistle to Des Cartes, has the follow- ing observation, which very much deserved the attention of that philosopher, and of all that come after him : — " When men, sit- ting in their closet, and consulting only their books, attempt disquisitions into nature, they may, indeed, tell how they would have made the world, if God had given them that in commission ; that is, they may describe [51] chimeras, which correspond with the imbecility of their own minds, no less than the admirable beauty of the universe cor- responds with the infinite perfection of its Creator ; but without an understanding truly divine, they can never form such an idea to themselves as the Deity had in creating things." Let us, therefore, lay down this as a fundamental principle in our inquiries into the structure of the mind and its opera- tions — that no regard is due to the conjec- tures or hypotheses of philosophers, how- ever ancient, however generally received. Let us accustom ourselves to try every opinion by the touchstone of fact and ex- perience. What can fairly be deduced from facts duly observed or sufficiently at- tested, is genuine and pure ; it is the voice of God, and no fiction of human imagina- tion. The first rule of philosophising laid down by the great Newton, is this : — Causas re- rum naturalium, non plurt$ admitti debere, quam quee et veree sint, et earum phceno menis explicnndis sufficiant. u No more causes, nor any other causes of natural effects, ought to be admitted, but such as are both true, and are sufficient for ex- plaining their appearances/* This is a golden rule ; it is the true and proper test, by which what is sound and solid in philoso- phy may be distinguished from what is hol- low and vain.* If a philosopher, therefore, pretends to shew us the cause of any natural effect, whether relating to matter or to mind, let us first consider whether there is sufficient • For this rule we are not indebted to Newton. It is only the old law of parcimony, and that ambigu- ous y expressed. For, in their plain meaning, the words " et rcree smt" are redundant ; or what follows is redundant, and the whole rule a barren truism,— H. evidence that the cause he assigns doss really exist. If there is not, reject it with disdain, as a fiction which ought to have no place in genuine philosophy. If the cause assigned really exists, consider, in the next place, whether the effect it is brought to explain necessarily follows from it. Un- less it has these two conditions, it is good for nothing. When Newton had shewn the admirable effects of gravitation in our planetary sys- tem, he must have felt a strong desire to know [52] its cause. He could have in- vented a hypothesis for this purpose, as many had done before him. But his phi- losophy was of another complexion. Let us hear what he says : Rationem harum ffravitatis proprielatum ex pkeenomenis rfm pitui deduce? e, et hypotheses non Jingo. Quit-quid enim eor-phecnomenis non dedueU tur hypothesis vocanda est. Et hypotheses^ seu melaphytkce, seu physices, seu qualila- tum occultaium, seu mech-trucee, in phtloso- phia experimentali locum non habent. CHAPTER IV. OF ANALOGY. It is natural to men to judge of things less known, by some similitude they ob- serve, or think they observe, between them and things more familiar or better known. In many cases, we have no better way of judging. And, where the things compared have really a great similitude in their na- ture, when there is reason to think that they are subject to the same laws, there may be a considerable degree of probability in con- clusions drawn from analogy. Thus, we may observe a very great si- militude between this earth which we in- habit, and the other planets, Saturn, Ju- piter, Mars, Venus, and Mercury. They all revolve round the sun, as the earth does, although at different distances and in different periods. They borrow all their light from the sun, as the earth does. Several of them are known to revolve round their axis like the earth, and, by that means, must have a like succession of day and night. Some of them have moons, that serve to give them light in the absence of the sun, as our moon does to us. They are all, in their motions, subject to the same law of gravitation, as the earth is. From all this similitude, it is not unrea- sonable to think, that those planets may, like our earth, be the habitation of va- rious [53] orders of living creatures. There is some probability in this conclusion from analogy. In medicine, physicians must, for the most part, be directed in their prescriptions IV.] OF ANALOGY. 237 by analogy. The constitution of one human body is so like, to that of another that it is reasonable to think that what is the cause of health or sickness to one, may have the same effect upon another. And this ge- nerally is found true, though not without some exceptions. In politics we reason, for the most part, from analogy. The constitution of human nature is so similar in different societies or commonwealths, that the causes of peace and war, of tranquillity and sedition, of riches and poverty, of improvement and degeneracy, are much the same in all. Analogical reasoning, therefore, is not, in all cases, to be rejected. It may afford a greater or a less degree of probability, according as the things compared are more or less similar in their nature. But it ought to be observed, that, as this kind of reasoning can afford only probable evidence at best ; so, unless great caution be used, we are apt to be led into error by it. For men are naturally disposed to conceive a greater similitude in things than there really is. To give an instance of this : Anatomists, in ancient ages, seldom dissected human bodies ; but very often the bodies of those quadrupeds whose internal structure was thought to approach nearest to that of the human body. Modern anatomists have discovered many mistakes the ancients were led into, by their conceiving a greater similitude between the structure of men and of some beasts than there is in reality. By this, and many other instances that might be given, it appears that conclusions built on analogy stand on a slippery founda- tion ; and that we ought never to rest upon evidence of this kind, when we can have more direct evidence. [54] I know no author who has made a more just and a more happy use of this mode of reasoning than Bishop Butler, in his " Ana- logy of Religion, Natural and Revealed, to the Constitution and Course of Nature." In that excellent work the author does not ground any of the truths of religion upon analogy, as their proper evidence. He only makes use of analogy to answer objec- tions against them. When objections are made against the truths of religion, which may be made with equal strength against what we know to be true in the course of nature, such objections can have no weight. Analogical reasoning, therefore, may be of excellent use in answering objections against truths which have other evidence. It may likewise give a greater or a less degree of probability in cases where we can find no other evidence. But all arguments, drawn from analogy, are still the weaker, the greater disparity there is between the f54. 55] things compared ; and, therefore, must be weakest of all when we compare body wiili mind, because there are no two things in nature more unlike. There is no subject in which men have always been so prone to form their notions by analogies of this kind, as in what re- lates to the mind. We form an early ac- quaintance with material things by means of our senses, and are bred up in a con- stant familiarity with them. Hence we are apt to measure all things by them ; and to ascribe to things most remote from mat- ter, the qualities that belong to material things. It is for this reason, that man- kind have, in all ages, been so prone to conceive the mind itself to be some sub- tile kind of matter : that they have been 'disposed to ascribe human figure and hu- man organs, not only to angels, but even to the Deity. Though we are conscious of the operations of our own minds when they are exerted, and are capable of attending to them, so as to form a distinct notion of them, this is so difficult a work to men whose attention is constantly solicited by external objects, that we give them names from things that are familiar, and which [55] are conceived to have some similitude to them ; and the notions we form of them are no less analogical than the names we give them. Almost all the words by which we express the operations of the mind, are borrowed from material objects. To un- derstand, to conceive, to imagine, to com- prehend, to deliberate, to infer, and many others, are words of this kind ; so that the very language of mankind, with regard to the operations of our minds, is analogical. Because bodies are affected only by con- tact and pressure, we are apt to conceive that what is an immediate object of thought, and affects the mind, must be in contact with it, and make some impression upon it. When we imagine anything, the very word leads us to think that there must be some image in the mind of the thing con- ceived. It is evident that these notions are drawn from some similitude conceived between body and mind, and between the properties of body and the operations of mind- To illustrate more fully that analogical reasoning from a supposed similitude of mind to body, which I conceive to be the most fruitful source of error with regard to the operations of our minds, I shall give an instance of it. When a man is urged by contrary motives — those on one hand inciting him to do some action, those on the other to forbear it — he deliberates about it, and at last resolves to do it, or not to do it. The contrary motiveo are here compared to the weights iu the opposite scales of a balance ; and there is 238 ON THE INTELLECTUAL POWERS. [essay I. not, perhaps, any instance that can be named of a more striking analogy between body and mind. Hence the phrases of weighing motives, of deliberating upon actions, are commott to all languages. From this analogy, some philosophers draw very important conclusions. They say, that, as the balance cannot incline to one side more than the other when the opposite weights are equal, so a man can- not possibly determine himself if the motives on both hands are equal ; and, as the bal- ance must necessarily turn to that side [56] which has most weight, so the man must necessarily be determined to that hand where the motive is strongest. And on this foundation some of the schoolmen* maintained that, if a hungry ass were placed between two bundles of hay equally inviting, the beast must stand still and starve to death, being unable to turn to either, because there are equal motives to both. This is an instance of that analogical rea- soning which I conceive ought never to be trusted ; for the analogy between a balance and a man deliberating, though one of the strongest that can be found between matter and mind, is too weak to support any argu- ment. A piece of dead inactive matter, and an active intelligent being, are things very unlike; and, because the one would remain at rest in a certain case, it does not follow that the other would be inactive in a case somewhat similar. The argument is no better than this — That, because a dead animal moves only as it is pushed, and, if pushed with equal force in contrary direc- tions, must remain at rest ; therefore, the same thing must happen to a living animal ; for, surely, th-e similitude between a dead animal and a living, is as great as that between a balance and a man. The conclusion I would draw from all that has been said on analogy, is, that, in our inquiries concerning the mind and its operations, we ought never to trust to rea- sonings drawn from some supposed simili- tude of body to mind ; and that we ought to be very much upon our guard that we be not imposed upon by those analogical terms and phrases, by which the operations of the mind are expressed in all languages. [57] • This illustration ts specially associated with Joannes Buridanus, a celebrated Nominalism of the 14th centurv, anclone-ol'tlie acutest reasoners on the great question of mnral liberty. The supposition of the ass, *c, is not, however, as I have ascertained, to be found in his writings. Perhaps it was orally advanced in disputation, or in lei'turing, as an ex- ample in illustration of his Determinism ; perhaps it was employed by his opponents as an instance to reduce that doctrine to absurdity. With this latter view, a similar refutation of the principles of our modern Fatalists was, as we have s L en, ingeniously essayed by Reid's friend and kinsman, I>r James Gregory. — H. CHAPTER V. OF THE PROPER MEANS OP KNOWING TH1 OPERATIONS OF THE MIND. Since we ought to pay no regard to hypo- theses, and to be very suspicious of analo- gical reasoning, it may be asked, From what source must the knowledge of the mind and its faculties be drawn ? I answer, the chief and proper source of this branch of knowledge is accurate reflec- tion upon the operations of our own minds. Of this source we shall speak more fully, after making some remarks upon two others that may be subservient to it. The first of them is attention to the structure of lan- guage. The language of mankind is expressive of their thoughts, and of the various opera- tions of their minds. The various opera- tions of the understanding, will, and pas- sions, which are common to mankind, have various forms of speech corresponding to them in all languages, which are the signs of them, and by which they are expressed : And a due attention to the signs may, in many cases, give considerable light to the things signified by them. There are in all languages modes of speech, by which men signify their judg- ment, or give their testimony; by which they accept or refuse ; by which they ask information or advice ; by which they com- mand, or threaten, or supplicate ; by which they plight their faith in promises or con - tracts. If such operations were not com- mon to mankind, we should not find in all languages forms of speech, by which they are expressed. All languages, indeed, have their imper- fections — they can never be adequate to all the varieties of human thought ; and there- fore things may be really distinct in their nature, and capable of being distinguished by the human mind, which are not distin- guished [58] in common language. We can only expect, in the structure of languages, those distinctions which all mankind in the common business of life have occasion to make. There may be peculiarities in a particular language, of the causes of which we are ignorant, and from which, therefore, we can draw no conclusion. But whatever we find common to all languages, must have a com- mon cause ; must be owing to some coir mon notion or sentiment of the human mind. We gave some examples of this before, and shall here add another. All languages have a plural number in many of their nouns ; from which we may infer that all men have notions, not of individual things [56-5Sj CHAP. V.] OPERATIONS OF THE MIND. 239 only, but of attributes, or things which are common to many individuals ; for jjo indi- vidual can have a plural number. Another source of information in this subject, is a due attention to the course of human actions and conduct. The actions of men are effects ; their sentiments, their passions, and their affections, are the causes of those effects ; and we may, in many cases, form a judgment of the cause from the effect. The behaviour of parents towards their children gives sufficient evidence even to those who never had children, that the parental affection is common to mankind. It is easy to see, from the general conduct of men, what are the natural objects of their esteem, their admiration, their love, their approbation, their resentment, and of all their other original dispositions. It is obvious, from the conduct of men in all ages, that man is by his nature a social animal ; that he delights to associate with his species ; to converse, and to exchange good offices with them. Not only the actions, but even the opi- nions of men may sometimes give light into the frame of the human mind. The opinions of men may be considered as the effects of their intellectual powers, [59] as their actions are the effects of their active principles. Even the prejudices and errors of mankind, when they are general, must have some cause no less general ; the dis- covery of which will throw some light upon the frame of the human understanding. I conceive this to be the principal use of the history of philosophy. When we trace the history of the various philosophical opin- ions that have sprung up among thinking men, we are led into a labyrinth of fanciful opinions, contradictions, and absurdities, intermixed with some truths ; yet we may sometimes find a clue to lead us through the several windings of this labyrinth. We may find that point of view which presented things to the author of the system, in the h\>ht in which they appeared to him. This will often give a consistency to things seem- ingly contradictory, and some degree of probability to those that appeared most fanciful. * The history of philosophy, considered as a map of the intellectual operations of men of genius, must always be entertaining, and may sometimes give us views of the human understanding, which could not easilybe had any other way. I return to what I mentioned as the main source of information on this subject — at- tentive reflection upon the operations of our own minds. • " Every error," say* Bossuet, " is a truth ■blued."— H. T59-611 All the notions we have of mind and nf its operations, are, by Mr Locke, called ideas of reflection.' A man may have as distinct notions of remembrance, of judg- ment, of will, of desire, as he has of any object whatever. Such notions, as Mr Locke justly observes, are got by tile power of reflection. But what is this power of reflection ? " It is," says the same author, "that power by which the mind turns its view inward, and observes its own actions and operations." He observes elsewhere, " That the understanding, like the eye, whilst it makes us see and perceive all [60] other things, takes no notice of itself ; and that it requires art and pains to set it at a distance, and make it its own object." Cicero hath expressed this sentiment most beautifully. Tusc. I. 28. This power of the understanding to make its own operations its object, to attend to them, and examine them on all sides, is the power of reflection, by which alone we can have any distinct notion of the powers of our own or of other minds. This reflection ought to be distinguished from consciousness, with which it is too often confounded, even by Mr Locke. All men are conscious of the operations of their own minds, at all times, while they are awake ; but there are few who reflect upon them, or make them objects of thought. From infancy, till we come to the years of understanding, we are employed solely about external objects. And, although the mind is conscious of its operations, it does not attend to them ; its attention is turned solely to the external objects, about which those operations are employed. Thus, when a man is angry, he is conscious of his pas- sion ; but his attention is turned to the person who offended him, and the circum- stances of the offence, while the passion of anger is not in the least the object of his attention. I conceive this is sufficient to shew the difference between consciousness of the operations of our minds, and reflection upon them ; and to shew that we may have the former without any degree of the latter. The difference between consciousness and reflection, is like to the difference between a superficial view of an object which pre- sents itself to the eye while we are engaged about something else, and that, attentive examination which we give to an object when we are wholly employed in surveying it. Attention is a voluntary act ; it re- quires an active exertion to begin and to continue it, and it may be continued as long as we will ; but consciousness [61] is * Locke is not {as Reid seems ta think, and as M. Stewart expressly says) the first who introduced Ke. flection either as a psychological term, or apsycholo. gical principle. See Note I — H, 240 ON THE INTELLECTUAL POWERS. £essay I, involuntary and of no continuance, changing with every thought. The power of reflection upon the oper- ations of their own minds, does not appear at all in children. Men must be come to some ripeness of understanding before they are capable of it. Of all the powers of the human mind, it seems to be the last that unfolds itself. Most men seem incapable of acquiring it in any considerable degree. Like all our other powers, it is greatly im- proved by exercise ; and until a man has got the habit of attending to the operations of his own mind, he can never have clear and distinct notions of them, nor form any steady judgment concerning them. His opinions must be borrowed from others, Ms notions confused and indistinct, and he may easily be led to swallow very gross absurd- ities. To acquire this habit, is a work of time and labour, even in those who begin it early, and whose natural talents are toler- ably fitted for it ; but the difficulty will be daily diminishing, and the advantage of it is great. They will, thereby, be enabled to think with precision and accuracy on every subject, especially on those subjects that are more abstract. They will be able to judge for themselves in many important points, wherein others must blindly follow a leader. CHAPTER VI. OF THK DIFFICULTY OF ATTENDING TO THE OPERATIONS OF OUR OWN MINDS. The difficulty of attending to our mental operations, ought to be well understood, and justly estimated, by those who would make any progress in this science ; that they may neither, on the one hand, expect success without pains and application of thought ; nor, on the other, be discouraged, by con- ceiving that the obstacles that lie in the way are insuperable, and that there is no cer- tainty to be attained in it. I shall, there- fore, endeavour to point [62] outthe causes of this difficulty, and the effects that have arisen from it, that we may be able to form a true judgment of both. 1 . The number and quick succession of the operations of the mind, make it difficult to give due attention to them. It is well known that, if a great number of objects be presented in quick succession, even to the eye, they are confounded in the memory and imagination. We retain a confused notion of the whole, and a more confused one of the several parts, especially if they are objects to which we have never before given particular attention. No succession con be more quick than that of thought. The mind is busy while we are awake, con- tinually passing from one thought and ona operation to another. The scene is con- stantly shifting. Every man will be sen- sible of this, who tries but for one minute to keep the same thought in his imagination, without addition or variation. He will find it impossible to keep the scene of his imagin- ation fixed. Other objects will intrude, without being called, and all he can do is to reject these intruders as quickly as possible, and return to his principal object. 2. In this exercise, we go contrary to habits which have been early acquired, and confirmed by long unvaried practice. From infancy, we are accustomed to attend to objects of sense, and to them only ; and, when sensible objects have got such strong hold of the attention by confirmed habit, it is not easy to dispossess them. When we grow up, a variety of external objects solicits our attention, excites our curiosity, engages our affections, or touches our pas- sions ; and the constant round of employ- ment, about external objects, draws off the mind from attending to itself; so that nothing is more just than the observation of Mr Locke, before mentioned, " That the understanding, like the eye, while it sur- veys all the objects around it, commonly takes no notice of itself." 3. The operations of the mind, from their very nature, lead the mind to give its atten- tion to some other object. Our sensations, [63] as will be shewn afterwards, are natu- ral signs, and turn our attention to the things signified by them ; so much that most of them, and those the most frequent and familiar, have no name in any language. In perception, memory, judgment, imagination, and reasoning, there is an object distinct from the operation itself ; and, while we are led by a strong impulse to attend to the object, the operation escapes our notice. Our passions, affections, and all our active powers, have, in like manner, their objects which engross our attention, and divert it from the passion itself. 4. To this we may add a just observation made by Mr Hume, That, when the mind is agitated by any passion, as soon as we turn our attention from the object to the passion itself, the passion subsides or van- ishes, and, by that means, escapes our inquiry. This, indeed, is common to almost every operation of the mind. When it is exerted, we are conscious of it ; but then we do not attend to the operation, but to its object. When the mind is drawn off from the object to attend to its own opera- tion, that operation ceases, and escapes our notice. 5. As it is not sufficient to the discovery of mathematical truths, that a man be able to attend to mathematical figures, as it is necessary that he should have the ability to ["62, 63] CHAP. VI.] OPERATIONS OF THE MIND. 241 listinguish accurately things that differ, and to discern clearly the various relations of the quantities he compares — an ability which, though much greater in those who have the force of genius than in others, yet, even in them, requires exercise and habit to bring it to maturity — so, in order to discover the truth in what relates to the operations of the mind, it is not enough that a man be able to give attention to them : he must have the ability to distinguish ac- curately their minute differences ; to resolve and analyse complex operations into their simple ingredients ; to unfold the ambiguity of words, which in this science is greater than in any other, and to give them the same accuracy and precision that mathematical terms have ; for, indeed, the same precision in the use of words, the same cool attention to [64] the minute differences of things, the same talent for abstraction and analys- ing, which fit a man for the study of math- ematics, are no less necessary in this. But there is this great difference between the two sciences — that the objects of mathematics being things external to the mind, it is much more easy to attend to them, and fix them steadily in the imagination. The difficulty attending our inquiries into the powers of the mind, serves to account for some events respecting this branch of philosophy, which deserve to be mentioned. While most branches of science have, either in ancient or in modern times, been highly cultivated, and brought to a con- siderable degree of perfection, this remains, to this day, in a very low state, and, as it were, in its infancy. Every science invented by men must have its beginning and its progress ; and, from various causes, it may happen that one science shall be brought to a great degree of maturity, while another is yet in its infancy. The maturity of a science may be judged of by this — When it contains a system of principles, and conclusions drawn from them, which are so firmly established that, among thinking and intelligent men, there remains no doubt or dispute about them ; so that those who come after may raise the superstructure higher, but shall never be able to overturn what is already built, in order to begin on ■■• new founda- tion. Geometry seems to have been in its in- fancy about the time of Thales and Pytha- goras ; because many of the elementary propositions, on which the whole science is built, are ascribed to them as the inventors. Euclid's " Elements," which were written some ages after rythagoras, exhibit a sys- tem of geometry which deserves the name of a science ; and, though great additions have been made by Apollonius, Archi- f64.-66l medes, Pappus, and others among the an- cients, and still greater by the moderns ; yet what [65] was laid down in Euclid's " Elements" was never set aside. It re- mains as the firm foundation of all future superstructures in that science. Natural philosophy remained in its in- fant state near two thousand years after geometry had attained to its manly form : for natural philosophy seems not to have been built on a stable foundation, nor carried to any degree of maturity, till the last cen- tury. The system of Des Cartes, which was all hypothesis, prevailed in the most enlight- ened part of Euvope till towards the end of last century. Sir Isaac Newton has the merit of giving the form of a science to this branch of philosophy ; and it need not ap- pear surprising, if the philosophy of the human mind should be a century or two later in being brought to maturity. It has received great accessions from the labours of several modern authors ; and perhaps wants little more to entitle it to the name of a science, but to be purged of cer- tain hypotheses, which have imposed on some of the most acute writers on this sub- ject, and led them into downright scepticism. What the ancients have delivered to us concerning the mind and its operations, is almost entirely drawn, not from accurate reflection, but from some conceived analogy between body and mind. And, although the modern authors I formerly named have given more attention to the operations of their own minds, and by that means have made important discoveries, yet, by re- taining some of the ancient analogical no- tions, their discoveries have been less use- ful than they might have been, and have led to scepticism. It may happen in science, as in building, that an error in the foundation shall weaken the whole ; and the farther the building is carried on, this weakness shall become the more apparent and the more threatening. Something of this kind seems to have hap- pened in our systems concerning the mind. The accession they [66] have received by modern discoveries, though very important in itself, has thrown darkness and obscurity upon the whole, and has led men rather to scepticism than to knowledge. This must be owing to some fundamental errors that have not been observed ; and when these are corrected, it is to be hoped that the im- provements that have been made will have their due effect. The last effect I observe of the difficulty of inquiries into the powers of the mind, is, that there is no other part of human know- ledge in which ingenious authors have been so apt to run into strange paradoxes, and even into gross absurdities. When we find philosophers maintaining B 242 ON -THE INTELLECTUAL POWER?. jj'JSSAY T. that there ia no heat in the fire, nor colour in the rainbow ;* when we find the gravest philosophers, from Des Cartes down to Bishop Berkeley, mustering up arguments to prove the existence of a material world, and unable to find any that will bear ex- amination ; when we find Bishop Berkeley and Mr Hume, the acutest metaphysicians uf the age, maintaining that there is no such thing as matter in the universe — that sun, moon, and stars, the earth which we inhabit, our own bodies, and those of our friends, are only ideas in our minds, and have no exist- ence but in thought ; when we find the last maintaining that there is neither body nor mind — nothing in nature but ideas and impressions, without any substance on which they are impressed — that there is no cer- tainty, nor indeed probability, even in ma- thematical axioms : I say, when we consider such extravagancies of many of the most acute writers on this subject, we may be apt to think the whole to be only a dream of fanciful men, who have entangled them- selves in cobwebs spun out of their own brain. But we ought to consider that the more closely and ingeniously men reason from false principles, the more absurdities they will be led into ; and when such absur- dities help to bring to light the false prin- ciples from which they are drawn, they may be the more easily forgiven. [67] CHAPTER VII. DIVISION OP THE POWERS OF THE MIND. The powers of the mind are so many, so various, and so connected and complicated in most of its operations, that there never has been any division of them proposed which is not liable to considerable objec- tions. We shall, therefore, take that gene- ral division which is the most common, into the powers of understanding and those of witl.\ Under the will we comprehend our active powers, and all that lead to action, or influence the mind to act — such as appe- tites, passions, affections. The understand- ing comprehends our contemplative powers ; by which we perceive objects ; by which we conceive or remember them ; by which we analyse or compoundthem ; and by which we judge and reason concerning them. • A merely verbal dispute. See before, p. 205, b, note.— H. t It would be out of place to enter on the exten. Bive field of history and discussion relative to the distribution of our mental powers. It is sufficient to say, that the vulgar division of the faculties, adopted by Reid, into those of the Understanding and those of the Will, is to be traced to the classifi- cation, taken in the Aristotelic school, of the powers into gnostic, or cognitive, and orectic, or appetent On this the reader may consult the admirable 'intro- duction of Philopon us—or rather of Ammonius Her. miae— to the books of Aristotle upon the Soul.— H. Although this general division may be of use in order to our proceeding more metho- dically in our subject, we are not to under- stand it as if, in those operations which are ascribed to the understanding, there were no exertion of will or activity, or as if the understanding were not employed in the operations ascribed to the will ; for I con- ceive there is no operation of the under- standing wherein the mind is not active in some degree. We have some command over our thoughts, and can attend to this or to that, of many objects which present themselves to our senses, to our memory, or to our imagination. ~YV"e can survey an object on this side or that, superficially or accurately, for a longer or a shorter time ; so that our contemplative powers are under . the guidance and direction of the active ; and the former never pursue their object without being led and directed, urged or restrained by the latter : and because the understanding is always more or less di- rected by the will, mankind have ascribed some degree of activity to [68] the mind in its intellectual operations, as well as in those which belong to the will, and have ex- pressed them by active verbs, such as see- ing, hearing, judging, reasoning, and the like. And as the mind exerts some degree of activity even in the operations of under- standing, so it is certain that there can be no act of will which is not accompanied with some act of understanding- The will must have an object, and that object must be apprehended or conceived in the under- standing. It is, therefore, to be remem- bered, that, in most, if not all operations of the mind, both faculties concur ; and we range the operation under that faculty which hath the largest share in it. * The intellectual powers are commonly divided into simple apprehension, judgment, and reasoning. -f As this division has in its favour the authority of antiquity, and of a very general reception, it would be im- proper to set it aside without giving any reason : I shall, therefore, explain it briefly, and give the reasons why I choose to follow another. * It should be always remembered that the various mental energies are all only possible in and through each other; and thatourpsychologicalanalysesdo not suppose any area! distinction of the operations which we discriminate by different names. Thought and volition can no more be exerted apart, than the sides and angles of a square can exist separately 'from each other.— H. f This is a singular misapprehension. The divi- sion in question, I make bold to sav, never was proposed by any philosopher as a ptychological dis- tribution of the cognitive faculties in general : on the contrary, it is only a logical distribution of .that section of the cognitive (acuities which we.denomi. nate discursive, as those alone which are proximately concerned in the process of reasoning— or thought, in its strictest signification. — H, [67, chap. vn. J DIVISION OF THE POWERS OF THE MIND. 243 It may be observed that, without appre- hension of the objects concerning which we judge, there can be no judgment ; as little can there be reasoning without both apprehension and judgment : these three operations, therefore, are not independent of each other. The' second includes the first, and the third includes both the first and second; but the first may be exer- cised without either of the other two. * It is on that account called simple apprehen- sion ; that is, apprehension unaccompanied with any judgment about the object appre- hended. This simple apprehension of an object is, in common language, called having a notion, or having a conception of the ob- ject, and by late authors is called having an idea of it. In speaking, it is expressed by a word, or by a part of a proposition, without that composition and structure which makes a complete sentence ; as a man, a man of fortune. Such words, taken by themselves, signify simple apprehen- sions. They neither affirm nor [69] deny; they imply no judgment or opinion of the thing signified by them ; and, therefore, cannot be said to be either true or false. The second operation in this division is judgment ; in which, say the philosophers, there must be two objects of thought com- pared, and some agreement or disagree- ment, or, in general, some relation discerned between them ; in consequence of which, there is an opinion or belief of that relation which we discern. This operation is ex- pressed in speech by a proposition, in which some relation between the things compared is affirmed or denied : as when we say, Alt men are fallible. Truth and falsehood are qualities which belong to judgment only ; or to proposi- tions by which judgment is expressed. Every judgment, every opinion, and every proposition, is either true or false. But words which neither affirm nor deny any- thing, can have neither of those qualities ; and the same may be said of simple appre- hensions, which are signified by such words. The third operation is reasoning ; in which, from two or more judgments, we draw a conclusion. This division of our intellectual powers corresponds perfectly with the account com- monly given by philosophers, of the suc- cessive steps by which the mind proceeds in the acquisition of its knowledge ; which are these three : First, By the senses, or by other means, it is furnished with various • This is.not correct. Apprehension is a* impos- sible without judgment, ?s judgment is impossible without apprehension. The apprehension of a thing or notion, is only realized in the mental affirmation that the concept ideally exists, and this affirmation is a judgment. In fact, all consciousness supposes a judgment, as all consciousness supposes a discrimina- tion.— H [69-71] simple apprehensions, notions, or ideas. These are the materials which nature gives it to work upon ; and from the simple ideas it is furnished with by nature, it forms various others more complex. Second:y, By comparing its ideas, and by perceiving their agreements and disagreements, it forms its judgments. And, Lastly, From two or more judgments, it deduces con- clusions of reasoning. Now, if all our knowledge is got by a procedure of this kind, [70] certainly the threefold division of the powers of under- standing, into simple apprehension, judg- ment, and reasoning, is the most natural and the most proper that can be devised. This theory and that division are so closely connected that it is difficult to judge which of them has given rise to the other ; and they must stand or fall together. But, if all our knowledge is not got by a process of this kind — if there are other avenues of knowledge besides the comparing our ideas, and perceiving their agreements and disagreements — it is probable that there ma v be operations of the understanding which cannot be properly reduced under any of the three that have been explained. Let us consider some of the most familiar operations of our minds, and see to which of the three they belong. I begin with consciousness. I know that I think, and this of all knowledge is the most certain. Is that operation of my mind which gives me this certain knowledge, to be called simple apprehension ? No, surely. Simple apprehension neither affirms nor denies. It will not be said that it is by reason- ing that I know that I think. It re- maius, therefore, that it must be by judg- ment — that is, according to the account given of judgment, by comparing two ideas, and perceiving the agreement between them. But what are the ideas compared ? They must be the idea of myself, and the idea of thought, for they are the terms of the proposition / think. According to this account, then, first, I have the idea of my- self and the idea of thought ; then, by com- paring these two ideas, I perceive that I think. Let any man who is capable of reflection judge for himself, whether it is by an opera- tion of this kind that he comes to be con- vinced that he thinks ? To me it appears evident, that the conviction I have that I think, is not got in this way ; and, therefore, I conclude, either that consciousness is not judgment, or that judgment is not rightly defined to be the perception of some agree- ment oi disagreement between two ideas. The perception of an object by my senses is another operation of [71] the understanding. 1 would know whether it be simple apprehension, or judgment, or It 2 214 ON THE INTELLECTUAL POWERS. [essay I. reasoning. It is not simple apprehension, because I am persuaded of the existence of the object as much as I could be by demon- stration. It is not judgment, if by judg- ment be meant the comparing ideas, and perceiving their # agreements or disagree- ments. It is not reasoning, because those who cannot reason can perceive. I find the same difficulty in classing me- mory under any of the operations men- tioned. There is not a more fruitful source of error in this branch of philosophy, than divisions of things which are taken to be complete when they are not really so. To make a perfect division of any class of things, a man ought to have the whole under his view at once. But the greatest capacity very often is not sufficient for this. Something is left out which did not come under the philosopher's view when he made his division : and to suit this to the division, it must be made what nature never made it. This has been so common a fault of philosophers, that one who would avoid error ought to be suspicious of divi- sions, though long received, and of great authority, especially when they are grounded on a theory that may be called in question. In a subject imperfectly known, we ought not to pretend to perfect divisions, but to leave room for such additions or alterations as a more perfect view of the subject may afterwards suggest. I shall not, therefore, attempt a com- plete enumeration of the powers of the hu- man understanding. I shall only mention those which I propose to explain ; and they are the following : — 1st, The powers we have by means of our external senses. 2dly, Memory. 3dly, Conception. ithly, The powers of resolv- ing and analysing complex objects, and compounding those that are more simple. Sthly, Judging. 6thly, Reasoning. Tthly, Taste. 8thly, Moral Perception ;* and, last of all, Consciousness.t [72] CHAPTER VIII. OP SOCIAL OPERATIONS OP MIND. There is another division of the powers of the mind, which, though it has been, ought not to be overlooked by writers on this subject, because it has a real founda- tion in nature. Some operations of our minds, from their very nature, are social, others are solitary. * Moral Perception is treated under the Active Powers, in Essay V.— H. t Consciousness obtains only an incidental consi- deration, under Judgment, in the Fifth Chapter of the Sixth Essay .— H. By the first, I understand such operations as necessarily suppose an intercourse with some other intelligent being. A man may understand and will ; he may apprehend, and judge, and reason, though he should know of no intelligent being in the universe besides himself. But, when he asks inform- ation, or receives it ; when he bears tes- timony, or receives the testimony of an- other ; when he asks a favour, or accepts one ; when he gives a command to his ser- vant, or receives one from a superior ; when he plights his faith in a promise or con- tract — these are acts of social intercourse between intelligent beings, and can have no place in solitude. They suppose under- standing and will ; but they suppose some- thing: more, which is neither understanding nor will ; that is, society with other intellU gent beings. They may be called intellec- tual, because they can only be in intellectual beings ; but they are neither simple appre- hension, nor judgment, nor reasoning, nor are they any combination of these operations. To ask a question, is as simple an opera- tion as to judge or to reason ; yet it is neither judgment nor reasoning, nor simple apprehension, nor is it any composition of these. Testimony is neither simple appre- hension, nor judgment, nor reasoning. The same may be said of a promise, or of a con- tract. These acts of mind are perfectly understood by every man of common under- standing ; but, when philosophers attempt to bring them within the pale of their divi- sions, by analysing them, they find inex- plicable mysteries, [73] and even contradic- tions, in them. One may see an instance of this, of many that might be mentioned, in Mr Hume's " Enquiry concerning the Principles of Morals," § 3, part 2, note, near the end. The attempts of philosophers to reduce the social operations under the common philosophical divisions, resemble very much the attempts of some philosophers to re- duce all our social affections to certain modifications of self-love. The Author of our being intended us to be social beings, and has, for that end, given us social intel- lectual powers, as well as social affections.* Both are original parts of our constitution, and the exertions of both no less natural than the exertions of those powers that are solitary and selfish. Our social intellectual operations, as well as our social affections, appear very early in life, before we are capable of reasoning ; yet both suppose a conviction of the exist- ence of other intelligent beings. When a child asks a question of his nurse, this act • " Man," says Aristotle, '* is, by nature, nr-re political than any bee or ant." And, in another woik, " Man is the sweetest thing to man"— i.flji- au vi%i?ov avffgwTflf. — H. [ 72, 73] chap, viii.3 OF SOCIAL OPERATIONS OF MIND. 245 of his mind supposes not only a desire to know what he asks ; it supposes, likewise, a conviction that the nurse is an intelligent being, to whom "he can communicate his thoughts, and who can communicate her thoughts to him. How he came by this conviction so early, is a question of some importance in the knowledge of the human mind, and, therefore, worthy of the con- sideration of philosophers. But they seem to have given no attention, either to this early conviction, or to those operations of mind which suppose it. Of this we shall have occasion to treat afterwards. All languages are fitted to express the social as well as the solitary operations of the mind. It may indeed be affirmed, that, to express the former, is the primary and direct intention of language. A man who had no intercourse with any other intelli- gent being, would never think of language. He would be as mute as the beasts of the field ; even more so, because they have some degree of social intercourse with one another, and some of them [74] with man. When language is once learned, it may be useful even in our solitary meditations ; and by clothing our thoughts with words, we may have a firmer hold of them. But this was not its first intention ; and the structure of every language shews that it is not intended solely for this purpose. In every language, a question, a com- mand, a promise, which are social acts, can be expressed as easily and as properly as judgment, which is a solitary act. The ex- pression of the last has been honoured with a particular name ; it is called a proposition ; it has been an object of great attention to philosophers ; it has been analysed into its very elements of subject predicate, and co- pula. All the various modifications of these, and of propositions which are compounded of' them, have been anxiously examined in many voluminous tracts. The expre-simi of a question, of a command, or of a pro- mise, is as capable of being analysed as a proposition is ; but we do not find that this has been attempted ; we have not so much as given them a name different from the operations which they express. Why have speculative men laboured so anxiously to analyse our solitary operations, and given so little attention to the social ? I know no other reason but this, that, in the divisions that have been made of the mind's operations, the social have been omitted, and thereby thrown behind the curtain. In all languages, the second person of verbs, the pronoun of the second person, and the vocative case in nouns, are appropriated to the expression of social operations of' mind, and could never have had place in language but for this purpose : nor is it a good argument against this observation, that, by a rhetorical figure, we sometimes address persons that are absent, or even inanimated beings, in the second person. For it ought to be remembered, that all figurative ways of using words or phrases suppose a natural and literal meaning of them.* [75] * What, throughout this chapter, is implied, ought to have been explicitly stated — that language is natu- ral to man; and consequently the faculty of speech ought to have been enumerated among the mental powers. — H. ESSAY II. OF THE POWERS WE HAVE BY MEANS OP OUR EXTERNAL SENSES. CHAPTER I. OF THE ORGANS OF SENSE. Of all the operations of our minds, the perception of external objects is the most familiar. The senses come to maturity even in infancy, when other powers have not yet sprung up. They are common to us with brute animals, and furnish us with the objects about which our other powers are the most frequently employed. We find it easy to attend to their operations ; and, because they are familiar, the names which properly belong to them are applied to other powers which are thought to re- semble them. For these reasons, they claim to be first considered. The perception of external objects is one main link of that mysterious chain which connects the material world with the intel- lectual. We shall find many things in this operation unaccountable ; sufficient to con- vince us that we know but little of our own frame ; and that a perfect comprehension of our mental powers, and of the manner of their operation, is beyond the reach of our understanding. In perception, there are impressions upon the organs of sense; the nerves, and brain, 2-16 ON THE INTELLECTUAL POWERS. [essay II, which, by the laws of our nature, are fol- I lowed by certain operations of mind. These two things are apt to be confounded ; but ought most carefully to be distinguished. Some philosophers, without good reason, have concluded, that the [7C] impressions made on the body are the proper efficient cause of perception. Others, with as little reason, have concluded that impressions are made on the mind similar to those made on the body. From these mistakes many others have arisen The wrong notions men have rashly taken up with regard to the senses, have led to wrong notions with regard to other powers which are conceived to resemble them. Many important powers of mind have, especially of late, been called internal fljnses, from a supposed resemblance to the external — such as, the sense of beauty, the sense of harmony, the moral sense.* And it is to be apprehended that errors, with regard to the external, have, from analogy, led to similar errors with regard to the internal ; it is, therefore, of some conse- quence, even with regard to other branches of our subject, to have just notions concern- ing the external senses. In order to this, we shall begin with some observations on the organs of sense, and on the impressions which in perception are made upon them, and upon the nerves and brain. IVe perceive no external object but by means of certain baddy organs which God has given us for that purpose. The Su- preme Being who made us, and placed us in this world, hath given us such powers of mind as he saw to be suited to our state and rank in his creation. He has given us the power of perceiving many objects around us — the sun, moon, and stars, the earth and sea, and a variety of animals, vegetables, and inanimate bodies. But our power of perceiving these objects is limited in various ways, and particularly in this — that, with- out the organs of the several senses, we perceive no external object. We cannot see wilhout eyes, nor hear without ears ; it is not only necessary that we should have these organs, but that they should be in a sound and natural state. There are many disorders of the eye that cause total blind- ness ; others that impair the powers of vi- sion, without destroying it altogether : and the same may be said of the organs of all the other senses. [77] All this is so well known from experience, ■that it needs no proof; but it ought to be observed, that we know it from experience only. We can give no reason for it, but that such is the will of our Maker. No man can shew it to be impossible to the Supreme Being to have given us the power of * He refers to Hutcheson.— H perceiving external objects without such or- gans/* We have reason to believe that, when we put off these bodies and all the organs belonging to them, our perceptive powers shall rather be improved than destroyed or impaired. We have reason to believe that the Supreme Being perceives everything in a much more perfect manner than we do, without bodily organs. We have reason to believe that there are other created beings endowed with powers of perception more perfect and more extensive than ours, with- out any such organs as we find necessary. We ought not, therefore, to conclude, that such bodily organs are, in their own nature, necessary to perception ; but rather that, by the will of God, our power of per- ceiving external objects is limited and cir- cumscribed by our organs of sense; so that we perceive objects in a certain manner, and in certain circumstances, and in no other, -f- If a man was shut up in a dark room, so that he could see nothing but through one small hole in the shutter of a window, would he conclude that the hole was the cause of his seeing, and that it is impos- sible to see any other way ? Perhaps, if he had never in his life seen but in this way, he might be apt to think so ; but the con- clusion is rash and groundless. He sees, because God has given him the power oi seeing ; and he sees only through this small hole, because his power of seeing is circum- scribed by impediments on all other hands. Another necessary caution in this matter is, that we ought not to confound the or- gans of perception with the being that per- ceives. Perception must be the act of some being that perceives. The eye [78] is not that which sees ; it is only the organ by which we see.$ The ear is not that which hears, but the organ by which we hear ; and so of the rest. § A man cannot see the satellites of Jupiter but by a telescope. Doesheconcludefrom this, that it is the telescope that sees those stars ? By no means — such a conclusion would be absurd. It is no less absurd to * However astonishing, it is now proved beyond all rational doubt, th it, in certain abnormal states of the nervous organism, perceptions are possible, through other than the ordinary channels of the senses. — H + The doctrine of Plato and of many other phi- losophers, Reid ought, however, to have said, limited to, instead of " by our organs of sense ;'' for, if the body be viewed as the prison of the soul, the senses mubt be viewed at leant as partial outlets.— H. t AioqQety.fA.mi ovx o$8atXf/,o7s ■ says Plato, followed by a host, ot philosophers, comparing the senses to windows of the mind. — H. § *■ 'I he mind fees," says Epicharmus — " the mind hears, all else is deaf and blind"— a saving alluded to as proverbial by Arislotle, in a passage to the same effect, which cannot adequately lie translated:— Xai£((T0£i Sa-Tie S/'jtfraj to, NS? o;f, * a.} tit i. x qui i. This Vas escaped (he coninieutatois.— H. Se«p.«7s.n. f76-78l ciiAP. ii.] OF IMPRESSIONS ON THE ORGANS, &c. 247 conclude that it is the eye that Eees, or the ear that hears. The telescope is an artificial organ of sight, but it sees not. The eye is a natural organ of sight, by which we see ; but the natural organ sees as little as the artificial. The eye is a machine ixnist admirably contrived for refracting the rays of light, and forming a distinct picture of objects upon the retina; but it sees neither the object nor the picture. It can form the picture after it is taken out of the head ; but no vision ensues. Even when it is in its proper place, and perfectly sound, it is well known that an obstruction in the optic nerve takes away vision, though the eye has performed all that belongs to it. If anything more were necessary to be said on a point so evident, we might ob- serve that, if the faculty of seeing were in the eye, that of hearing in the ear, and so of the other senses, the necessary conse- quence of this would be, that the thinking principle, which I call myself, is not one, but many. But this is contrary to the ir- resistible conviction of every man. When I say I see, I hear, I feel, I remember, this implies that it is one and the same self that performs all these operations; and, as it would be absurd to say that my memory, another man's imagination, and a third man's reason, may make one individual intelligent being, it would be equally ab- surd to say that one piece of matter see- ing, another hearing, and a third feeling, may make one and the same percipient being. These sentiments are not new ; they have occurred to thinking men from early ages. Cicero, in his " Tusculan Questions," Book I., chap. 20, has expressed them very dis- tinctly. Those who choose may consult the passage.* [79] CHAPTER II. OFTHE IMPRESSIONS ON THE ORGANS, NERVES, AND BRAINS. A second law of our nature regarding perception is, that u-e perceive no object, unless some impression is made upon the organ of sense, either by .the immediate application of the object, or by some medium which passes between the object and the organ. In two of our senses — to wit, touch and teste — there must be an immediate applica- tion of the object to the organ. In the other three, the object is perceived at a dis- tance, but still by means of a medium, by * Cicero saya n-tl-ing on this head tliat had not been said hcfi re him by tl-e Greek rhii ;,Oj-hcrs — H. [79, POT which some impression is made upon the organ." The effluvia of bodies drawn into the nostrils with the breath, are the medium of smell ; the undulations of the air are the medium of hearing ; and the rays of light passing from visible objects to the eye, are the medium of sight. We see no object unless rays of light come from it to the eye. We hear not the sound of any body, unless the vibrations of some elastic medium, oc- casioned by the tremulous motion of the sounding body, reach our ear. We per- ceive no smell, unless the effluvia of the smelling body enter into the nostrils. We perceive no taste, unless the sapid body be applied to the tongue, or some part of the organ of taste. Nor do we perceive any tangible quality of a body, unless it touch the hands, or some part of our bodies. These are facts known from experience to hold universally and invariably, both in men and brutes. By this law of our na- ture, our powers of perceiving external ob- jects, are farther limited and circumscribed. Nor can we give any other reason for this, than [80] that it is the will of our Maker, who knows best what powers, and what degrees of them, are suited to our state. We were once in a state, I mean in the womb, wherein our powers of perception were more limited than in the present, and, in a future state, they may be more enlarged. It is likewise a law of our nature, that, in order to our perceiving objects, the im- pressions made upon the organs of sense must be communicated to the nerves, and by them to the brain. This is perfectly known to those who know anything of ana- tomy. The nerves are fine cords, which pass from the brain, or from the spinal marrow, which is a production of the brain, to all parts of the body, dividing into smaller branches as they proceed, until at last they escape our eyesight : and it is found by experience, that all the voluntary and in- voluntary motions of the body are performed by their means. When the nerves that serve any limb, are cut, or tied hard, we have then no more power to move that limb than if it was no part of the body. As there are nerves that serve the mus- cular motions, so there are others that serve the several senses ; and as without the for- mer we cannot move a limb, so without the latter we can have no perception. • This distinction of a mediate and immediate ob. Ject. or of an object and a medium, in perception, is inaccurate, and a eource of sad confusion. We per- ceive, and can perceive, nothing but what is in rela. tion to the organ, and nothing is in relation to the organ that is not present to it. Ail tbesenses are, in tact, modifications of touch, as Dcmticritus of old taught. Wc reach the distant reality, not tty senses not by perception, tint by inference. Keicl, how. ever, in this only follows his predecessor* — H, 243 ON THE INTELLECTUAL POWERS. [ESSAY II. This train of machinery the wisdom of God has made necessary to our perceiving objects. Various parts of the body concur to it, and each has its own function. First, The object, either immediately, or by some medium, must make an impression on the organ. The organ serves only as a medium by which an impression is made on the nerve ; and the nerve serves as a medium to make an impression upon the brain. Here the material part ends; at least we can trace it no farther ; the rest is all in- tellectual. * The proof of these impressions upon the nerves and brain in [81] perception is this, that, from many observations and experi- ments, it is found that, when the organ of any sense is perfectly sound, and has the impression made upon it by the object ever so strongly, yet, if the nerve which serves that organ be cut or tied hard, there is no perception ; and it is well known that dis- orders in the brain deprive us of the power of perception when both the organ and its nerve are sound. There is, therefore, sufficient reason to conclude that, in perception, the object pro- duces some change in the organ ; that the organ produces some change upon the nerve; and that the nerve produces some change in the brain. And we give the name of an impression to those changes, because we have not a name more proper to express, in a general manner, any change produced in a body, by an external cause, without specifying the nature of that change. Whether it be pressure, or at- traction, or repulsion, or vibration, or some- thing unknown, for which we have no name, still it may be called an impression. But, with regard to the particular kind of this change or impression, philosophers have never been able to discover anything at all. But, whatever be the nature of those im- pressions upon the organs, nerves, and brain, we perceive nothing without them. Experience informs that it is so ; but we cannot give a reason why it is so. In the constitution of man, perception, by fixed laws of nature, is connected with those im- pressions ; but we can discover no neces- sary connection. The Supreme Being has seen fit to limit our power of perception ; so that we perceive not without such impres- sions; and this is all we know of the matter. This, however, we have reason to con- * There can be no doubt that the whole organism ofthescnse, from periphery to centre, must co-operate simultaneously in perception ; but there is no rea- son to place the mind at the central extremity nlotic, Hhtl to hold that not only a certain series of organic changes, but a scn-ation, must precede the mental cognition This is mere hypothesis, and opyoacd 10 the testimony of consciousness, — K. elude in general — that, as the impressions on the organs, nerves, and brain, correspond exactly to the nature and conditions of the objects by which they are made, so our perceptions and sensations correspond to those impressions, and vary in kind, and in degree, as they vary. [ 82 ] Without this exact correspondence, the information we receive by our senses would not only be imperfect, as it undoubtedly is, but would be fallacious, which we have no reason to think it is. CHAPTER III. HYPOTHESES CONCERNING THE NERVES AND BRAIN. We are informed by anatomists, that, al- though the two coats which inclose a nerve, and which it derives from the coats of the brain, are tough and elastic, yet the nerve itself has a very small degree of consistence, being almost like marrow. It has, how- ever, a fibrous texture, and may be divided and subdivided, till its fibres escape our senses ; and, as we know so very little about the texture of the nerves, there is great room left for those who choose to indulge themselves in conjecture. The ancients conjectured that the ner- vous fibres are fine tubes, filled with a very subtile spirit, or vapour, which they called animal spirits ; that the brain is a gland, by which the animal spirits are secreted from the finer part of the blood, and their continual waste repaired ; and that it is by these animal spirits that the nerves perform their functions. Des Cartes has shewn how, by these animal spirits, going and re- turning in the nerves, muscular motion, perception, memory, and imagination, are effected. All this he has described as dis- tinctly as if he had been an eye-witness of all those operations. But it happens that the tubular structure of the nerves was never perceived by the human eye, nor shewn by the nicest injections ; and all that has been said about animal spirits, through more than fifteen centuries, is mere con- jecture. Dr Briggs, who was Sir Isaac Newton's master in anatomy, was the first, as far as I know, who advanced a new system concerning [83] the nerves. - Heconceived them to be solid filaments of prodigious - Briggs was not the first The Jesuit, Hon •- ratus r-ai.ry, had before him denial the old hypothe- sis of spirits ; and the new hypothesis of cerebral fibres, and fibril, hj which he explains the phseno- mer-a (ifscinc, imagination ami memory, is not on v the first, but perhaps the most ingenious of the class that has been proposed. Yet ihe very name of Fabry it. wholly uiiiAiticed by those historians of philosophy who do not dcpmit ,sui crflurus to dwell on the tire «inne reveries of Briggs, Hartley, ;md Bonnet. — H. [81-83] chap, in.] HYPOTHESES CONCERNING THE NERVES, &c. 24J tenuity ; and this opinion, as it accords bet- ter with observation, seems to have been more generally received since his time. As to the manner of performing their office, Dr Briggs thought that, like musical cords, they have vibrations differing according to their length and tension. They seem, how- ever, very unfit for this purpose, on account of their want of tsuacity, their moisture, and being through their whole length in contact with moist substances ; so that, al- though !>r Briggs wrote a book upon this system, called Nova Visionis Theoria, it seems not to have been much followed. Sir Isaac Newtonjjn all his philosophical writingsjtook great care to distinguish his doctrines, which he pretended to prove by just induction, from his conjectures, which were to stand or fall according as future experiments and observations should esta- blish or refute them. His conjectures he has put in the form of queries, that they might not be received as truths, but be inquired into, and determined according to the evidence to be found for or against them. Those who mistake his queries for a part of his doctrine, do him great injus- tice, and degrade him to the rank of the common herd of philosophers, who have in all ages adulterated philosophy, by mixing conjecture with truth, and their own fancies with the oracles of Nature. 1 Among other queries, this truly great philosopher pro- posed this, Whether there may not be an elastic medium, or eether, immensely more rare than air, which pervades all bodies, and which is the cause of gravitation ; of the refraction and reflection of the rays of light ; of the transmission of heat, through spaces void of air ; and of many other phse- nomena ? In the 23d query subjoined to his " Optics," he puts this question with regard to the impressions made on the nerves and brain in perception, Whether vision is effected chiefly by the vibrations of this medium, excited in the bottom of the eye by the rays of light, and propagated along the solid, pellucid, and uniform capillaments of the optic nerve ? And whether hearing is effected [84] by the vibrations of this or some other medium, excited by the tremor of the air in the auditory nerves, and pro- pagated along the solid, pellucid, and uni- form capillaments of those nerves ? And so with regard to the other senses. What Newton only proposed as a matter to be inquired into, Dr Hartley conceived to have such evidence, that, in his " Ob- servations on Man," he has deduced, in a mathematical form, a very ample system concerning the faculties of the mind, from the doctrine of vibrations, joined with that of association. His notion of the vibrations excited in the nerves, is expressed in Propositions 4 [84., 85] and 5 of the first part of his " Observa- tions on Man." " Prop. 4. External objects impressed on the senses occasion, first in the nerves on which they are impressed, and then in the brain, vibrations of the small, and, as one may say, infinitesimal medullary particles. Prop. 5. The vibra- tions mentioned in the last proposition are excited, propagated, and kept up, partly by the sether — that is, by a very subtile elastic fluid ; partly by the uniformity, continuity, softness, and active powers of the medullary substance of the brain, spinal manrow, and nerves." The modesty and diffidence with which Dr Hartley offers his system to the world — by desiring his reader " to expect nothing but hints and conjectures in difficult and obscure matters, and a short detail of the principal reasons and evidences in those that are clear ; by acknowledging, that he shall not be able to execute, with any ac- curacy, the proper method of philosophising, recommended and followed by Sir Isaac Newton ; and that he will attempt a sketch only for the benefit of future enquirers" — seem to forbid any criticism upon it. One cannot, without reluctance, criticise what is proposed in such a ' manner, and with so good intention ; yet, as the tendency of this system of vibrations is to make all the oper- ations of the mind mere mechanism, depend- ent [85] on the laws of matter and motion, and, as it has been held forth by its vota- ries, as in a manner demonstrated, I shall make some remarks on that part of the sys- tem which relates to the impressions made on the nerves and brain in perception. It may be observed, in general, that Dr Hartley's work consists of a chain of pro- positions, with their proofs and corollarieo, digested in good order, and in a scientific form. A great part of them, however, are, as he candidly acknowledges, conjectures and hints only ; yet these are mixed with the propositions legitimately proved, with- out any distinction. Corollaries are drawn from them, and other propositions grounded upon them, which, all taken together, make up a system. A system of this kind re- sembles a chain, of which some links are abundantly strong, others very weak. The strength of the chain is determined by that of the weakest links ; for, if they give way, the whole falls to pieces, and the weight supported by it falls to the ground. Philosophy has been, in all ages, adul- terated by hypotheses ; that is, by systems built partly on facts, and much upon con- jecture. It is pity that a man of Dr Hart- ley's knowledge and candour should have followed the multitude in this fallacious tract, after expressing his approbation of the proper method of philosophising, pointed out by Bacon and Newton. The last con- 250 ON THE INTELLECTUAL POWERS. £essat II. sidered it as a reproach when his system was called his hypothesis ; and says, with disdain of such imputation, Hypotheses non Jingo. And it is very strange that Dr Hartley should not only follow such a me- thod of philosophising himself, but that he should direct others in their inquiries to follow it. So he does in Proposition 87, Part I., where he deduces rules for the ascertainment of truth, from the rule of false, in arithmetic, and from the art of decyphering ; and in other places. As to the vibrations and vibratiuncles, whether of an elastic aether, or of the in- finitesimal particles of the brain and nerves, there [86] may be such things for what we know ; and men may rationally inquire whether they can find any evidence of their existence ; but, while we have no proof of their existence, to apply them to the solu- tion of pliEenomena, and to build a system upon them, is what I conceive we call build- ing a castle in the air. When men pretend to account for any of the operations of Nature, the causes assigned by them ought, as Sir Isaac New- ton has taught us, to have two conditions, otherwise they are good for nothing. First, They ought to be true, to have a real exist- ence, and not to be barely conjectured to exist, without proof. Secondly, They ought to be sufficient to produce the effect. As to the existence of vibratory motions in the medullary substance of the nerves and brain, the evidence produced is this : First, It is observed that the sensations of seeing and hearing, and some sensations of touch, have some short duration and con- tinuance. Secondly, Though there be no direct evidence that the sensations of taste and smell, and the greater part of these of touch, have the like continuance, yet, says the author, analogy would incline one to believe that they must resemble the sensa- tions of sight and hearing in this particular. Thirdly, The continuance of all our sensa- tions being thus established it follows, that external objects impress vibratory motions on the medullary substance of the nerves and brain ; because no motion, besides a vibratory one, can reside in any part for a moment of time. This is the chain of proof, in which the first link is strong, being confirmed by ex- perience ; the second is very weak ; and the third still weaker. For other kinds of mo- tion, besides that of vibration, may have some continuance — such as rotation, bending or unbending of a spring, and perhaps others v\ Inch we are unacquainted with ; nor do we know whether it is motion that is pro- duced in the nerves — it may be pressure, attraction, repulsion, or something we do not know. This, indeed, is the common refuge of all hypotheses, [87] that wc know no other way in which the phenomena may be produced, and, therefore, they must be produced in this way. There is, therefore, no proof of vibrations in the infinitesimal particles of the brain and nerves. It may be thought that the existence of an elastic vibrating aether stands on a firmer foundation, having the authority of Sir Isaac Newton. But it ought to be observed that, although this great man had formed conjectures about this aether near fifty years before he died, and had it in his eye during that long space as a subject of in- quiry, yet it does not appear that he ever found any convincing proof of its existence, but considered it to the last as a question whether there be such an aether or not. In the premonition to the reader, prefixed to the second edition of his " Optics," anno 1717, he expresses himself thus with regard to it : — " Lest any one should think that I place gravity among the essential properties of bodies, I have subjoined one question concerning its cause ; a question, 1 say, for I do not hold it as a thing estab- lished." If, therefore, we regard the authority of Sir Isaac Newton, we ought to hold the existence of such an tether as a matter not established by proof, but to be examined into by experiments ; and I have never heard that, since his time, any new evidence has been found of its existence. " But," says Dr Hartley, " supposing the existence of the sether, and of its pro- perties, to be destitute of all direct evidence, still, if it serves to account for a great variety of phaenomena, it will have an in- direct evidence in its favour by this means." There never was an hypothesis invented by an ingenious man which has not this evi- dence in its favour. The vortices of Des Cartes, the sylphs and gnomes of Mr Pope, serve to account for a great variety of phaenomena. When a man has, with labour and in- genuity, wrought up an hypothesis into a system, he contracts a fondness for it, which is apt [88] to warp the best judgment. This, I humbly think, appears remarkably in Dr Hartley. In his preface, he declares his approbation of the method of philoso- phising recommended and followed by Sir Isaac Newton ; but, having first deviated from this method in his practice, he is brought at last to justify this deviation in theory, and to bring arguments in defence of a method diametrically opposite to it. " Wo admit," says he, " the key of a cypher to be a true one when it explains the cypher completely." I answer, To find the key requires an understanding equal or supe- rior to that which made the cypher. This instance, therefore, will then be in point, when he who attempts to decypher the works of Nature by an hypothesis, has an [8G-88"] ohap. m.] HYPOTHESES CONCERNING THE NERVES, &c. 251 understanding equal or superior to that which made them. The votaries of hypo- theses have often been challenged to shew one useful discovery in the works of Nature that was ever made in that way. If in- stances of this kind could be produced, we ought to conclude that Lord Bacon and Sir Isaac Newton have done great disser- vice to philosophy by what they have said against hypotheses. But, if no such in- stance can be produced, we must conclude, with those great men, that every system which pretends to account for the phseno- mena of Nature by hypotheses or conjecture, is spurious and illegitimate, and serves only to flatter the pride of man with a vain con- ceit of knowledge which he has not attained. The author tells us, "that any hypo- thesis that has so much plausibility as to explain a considerable number of facts, helps us to digest these facts in proper order, to bring new ones to light, and to make e.r- perimenta crucis for the sake of future inquirers." Let hypotheses be put to any of these uses as far as they can serve. Let them suggest experiments, ordirect our inquiries ; but let just induction alone govern our belief. " The rule of false affords an obvious and strong instance of the possibilityof being led, with precision and certainty, to a [89] true conclusion from a false position. And it is of the very essence of algebra to proceed in the way of supposition." This is true ; but, when brought to jus- tify the accounting for natural phaanomena by hypotheses, is foreign to the purpose. When an unknown number, or any un- known quantity, is sought, which must have certain conditions, it may be found in a scientific manner by the rule of false, or by an algebraical analysis ; and, when found, may be synthetically demonstrated to be the number or the quantity sought, by its answering all the conditions required. But it is one thing to find a quantity which shall have certain conditions ; it is a very different thing to find out the laws by which it pleases God to govern the world and produce the pliEenomena which fall under our observation. And we can then only allow some weight to thisargumeut in favour of hypotheses, when it can be shewn that the cause of any one phenomenon in nature has been, or can be found, as an unknown quantity is, by the rule of false, or by alge- braical analysis. This, I apprehend, will never be, till the tera arrives, which Dr Hartley seems to foretell, " When future generations shall put all kinds of evidences and enquiries into mathematical forms ; and, as it were, reduce Aristotle's ten Ca- tegories, and Bishop Wilkin's forty Summit Uetiera to the head of quantity alone, so as [89, 90] to make mathematics and logic, natural history and civil history, natural philoso- phy and philosophy of all other kinds, coincide owni ex parte." Since Sir Isaac Newton laid down the rules of philosophising in our inquiries into the works of Nature, many philosophers have deviated from them in practice ; per- haps few have paid that regard to them which they deserve. But they have met with very general approbation, as being founded in reason, and pointing out the only path to the knowledge of Nature's works. Dr Hartley is the only author I have met with who reasons against them, and has taken pains to find out arguments in defence of the exploded method of hy- pothesis. [90] Another condition which Sir Isaac New- ton requires in the causes of natural things assigned by philosophers, is, that they be sufficient to account for the phaanomena. Vibrations, and vibratiuncles of the me- dullary substance of the nerves and brain, are assigned by Dr Hartley to account W all our sensations and ideas, and, in a word, for all the operations of our minds. Let us consider very briefly how far they are sufficient for that purpose. It would be injustice to this author to conceive him a materialist. He proposes his sentiments with great candour, and they ought not to be carried beyond what his words express. He thinks it a consequence of his theory, that ■ matter, if it can be endued with the most simple kinds of sens- ation, might arrive at all that intelligence of which the human mind is possessed. He thinks that his theory overturns all the arguments that are usually brought for the immateriality of the soul, from the subtilty of the internal senses, and of the rational faculty ; but he does not take upon him to determine whether matter can be endued with sensation or no. He even acknowledges that matter and motion, however subtilly divided and reasoned upon, yield nothing more than matter and motion still ; and therefore he would not be any way interpreted so as to oppose the imma- teriality of the soul. It would, therefore, be unreasonable to require that his theory of vibrations should, in the proper sense, account for our sensa- tions. It would, indeed, be ridiculous in any man to pretend that thought of any kind must necessarily result from motion, or that vibrations in the nerves must neces- sarily produce thought, any more than the vibrations of ,a pendulum. Dr Hartley disclaims this way of thinking, and there- fore it ought not to be imputed to him. All that he pretends is, that, in the human constitution, there is a certain connection between vibrations in the medullary sub- 252 ON THE INTELLECTUAL POWERS. Qessat II. stance of the nerves and brain, and the thoughts of the mind ; so that the last de- pend entirely upon the first, and every kind of thought [91] in the mind arises in conse- quence of a corresponding vibration, or vibratiuncle in the nerves and brain. Our sensations arise from vibrations, and our ideas from vibratiuncles, or miniature vibra- tions ; and he comprehends, under these two words of sensations and ideas, all the operations of the mind. But how can we expect any proof of the connection between vibrations and thought, when the existence of such vibrations was never proved ? The proof of their connec- tion cannot be stronger than the proof of their existence ; for, as the author acknow- ledges that we cannot infer the existence of the thoughts from the existence of the vibrations, it is no less evident that we can- not infer the existence of vibrations from the existence of our thoughts. The exist- ence of both must be known before we can know their connection. As to the exist- ence of our thoughts, we have the evidence of consciousness, a kind of evidence that never was called in question. But as to the existence of vibrations in the medullary substance of the nerves and brain, no proof has yeFbeen brought. All, therefore, we have to expect from this hypothesis, is, that in vibrations, con- sidered abstractly, there should be a variety in kind and degree, which tallies so exactly with the varieties of the thoughts they are to account for, as may lead us to suspect some connection between the one and the other. If the divisions and subdivisions of thought be found to run parallel with the divisions and subdivisions of vibrations, this would give that kind of plausibility to the hypo- thesis of their connection, which we com- monly expect even in a. mere hypothesis ; but we do not find even this. For, to omit all those thoughts and oper- ations which the author comprehends under the name of ideas, and which he thinks arc connected with vibratiuncles ; to omit the perception of external objects, which he comprehends under the name of sensations ; to omit the sensations, properly so called, which accompany our passions [92] and affections, and to confine ourselves to the sensations which we have by means of our external senses, we can perceive no corre- spondence between the variety we find in their kinds and degrees, and that which may be supposed in vibrations. . We have five senses, whose sensations differ totally in kind. By each of these, excepting perhaps that of hearing, we have a variety of sensations, which differ specific- ally, and not in degree only. How many tastes and smells are there which are spe- fically differeut, each of them capable of all degrees of strength and weakness ? Heat and cold, roughness and smoothness, hard- ness and softness, pain and pleasure, are sensations of touch that differ in kind, and each has an endless variety of degrees. Sounds have the qualities of acute and grave, loud and low, with all different de- grees of each. The varieties of colour are many more than we have names to express. How shall we find varieties in vibrations corresponding to all this variety of sensa- tions which we have by our five senses only ? I know two qualities of vibrations in an uniform elastic medium, and I know no more. They may be quick or slow in vari- ous degrees, and they may be strong or weak in various degrees ; but I cannot find any division of our sensations that will make them tally with those divisions of vibra- tions. If we had no other sensations but those of hearing, the theory would answer well; for sounds are either acute or grave, which may answer to quick or slow vibra- tions ; or they are loud or low, which an- swer to strong or weak vibrations. But then we have no variety of vibratious cor- responding to the immense variety of sens- ations which we have by sight, smell, taste, and touch. Dr Hartley has endeavoured to find out other two qualities of vibrations ; to wit, that they may primarily affect one part of the brain or another, and that they may vary in their direction according as they enter by different external nerves ; but these [93] seem to be added to make a number; for, as far as we know, vibrations in an uniform elastic substance spread over the whole, and in all directions. However, that we may be liberal, we shall grant him four different kinds of vibrations, each of them having as many degrees as he pleases. Can he, or any man, reduce all our sensa- tions to four kinds ? We have five senses, and by each of them a variety of sensations, more than sufficient to exhaust all the varieties we are able to conceive in vibra- tions. Dr Hartley, indeed, was sensible of the difficulty of finding vibrations to suit all the variety of our sensations. His extensive knowledge of physiology and pathology could yield him but a feeble aid ; and, there- fore, he is often reduced to the necessity of heaping supposition upon supposition, con- jecture upon conjecture, to give some credi- bility to his hypothesis ; and, in seeking out vibrations which may correspond with the sensations of one sense, he seems to forget that those must be omitted which have been appropriated to another. Philosophers have accounted in some de- gree for our various sensations of sound by the vibrations of elastic air; but it is to be r91-93] CHAP. 1V.J FALSE CONCLUSIONS, &c. 253 observed, first, That we know that such vi- brations do really exist ; and, secondly, That they tally exactly with the most remarkable phenomena of sound. We cannot, indeed, shew how any vibration should produce the sensation of sound. This must be resolved into the will of God, or into some cause altogether unknown. But we know that, as the vibration is strong or weak, the sound is loud or low ; we know that, as the vibration is quick or slow, the sound is acute or grave. We can point out that relation of synchronous vibrations which produces harmony or discord, and that relation of successive vibrations which pro- duces melody ; and all this is not conjec- tured, but proved by a sufficient induction. This account of sounds, therefore, is philo- sophical : although, perhaps, there may be many things relating to sound that we can- not account for, and of which the causes remain latent. The connections described [94] in this branch of philosophy are the work of Gou, and not the fancy of men. If anything similar to this could be shewn in accounting for all our sensations by vibrations in the medullary substance of the nerves and brain, it would deserve a place in sound philosophy ; but, when we are told of vibrations in a substance which no man could ever prove to have vibrations, or to be capable of them ; when such imaginary vibrations are brought to account for all our sensations, though we can perceive no cor- respondence in their variety of kind and degree to the variety of sensations — the con- nections described in such a system are the creatures of human imagination, not the work of God. The rays of light make an impression upon the optic nerves ; but they make none upon the auditory or olfactory. The vibra- tions of the air make an impression upon the auditory nerves ; but none upon the optic or the olfactory. The effluvia of bodies make an impression upon the olfac- tory nerves ; but make none upon the optic or auditory. No man has been able to give a shadow of reason for this. While this is the case, is it not better to confess our ignorance of the nature of those impressions made upon the nerves and brain in percep- tion, than to flatter our pride with the con- ceit of knowledge which we have not, and to adulterate philosophy with the spurious brood of hypotheses ?* * Reid appears to have been unacquainted with the works and theory of Bonnet. — With our author's strictures on the physiological hypotheses, the reader may compare those of Tetens, in his " Versuche." and of Stewart in his " Philosophical Essays." — H, f°4, 95] CHAPTER IV. FALSE CONCLUSIONS DRAWN FROM THB IMPRESSIONS BEFORE MENTIONED. Some philosophers among the ancients, as well as among the moderns, imagined that man is nothing but a piece of matter, so curiously organized that the impressions of external objects produce in it sensation, perception, remembrance, and all the other operations [95] we are conscious of.* This foolish opinion could only take its rise from observing the constant connection which the Author of Nature hath established be- tween certain impressions made upon our senses and our perception of the objects by which the impression is made ; from which they weakly inferred that those impressions were the proper efficient causes of the cor- responding perception. But no reasoning is more fallacious than this — that, because two things are always conjoined, therefore one must be the cause of the other. Day and night have been joined in a constant succession since the beginningof the world; but who is so foolish as to conclude from this that day is the cause of night, or night the cause of the following day ? There is indeed nothing more ridiculous than to imagine that any motion or modification of matter should pro- duce thought. If one should tell of a telescope so exactly made as to have the power of seeing ; of a whispering gallery that had the power of hearing ; of a cabinet so nicely framed as to have the power of memory ; or of a machine so delicate as to feel pain when it was touched — such absurdities are so shocking to common sense that they would not find belief even among savages; yet it is the same absurdity to think that the impressions of external objects upon the machine of our bodies can be the real efficient cause of thought and perception. Passing this, therefore, as a notion too absurd to admit of reasoning, another con- clusion very generally made by philoso- phers is, that, in perception, an impression is made upon the mind as well as upon the organ, nerves, and brain. Aristotle, as was before observed, thought that the form or image of the object perceived, enters by * The Stoics are leprehended for such a doctrine by Boethius: — •' Quondam porticus attulit Obscuros nimiuro sencs, Qui sensus ct imagines E corporibus extunis Credant mentibus imprimi, LH quf.mtam celeri stylo Mos est aequore pagina? Quae uullas habeat notas, Piessas figere Iiteras." &c The tabula rasa remounts, however, to Arisujtb — indeed to Plato— as an illustration. — H. 254 ON THE INTELLECTUAL POWERS. [ESSAY II, the organ of sense, and strikes upon the mind.* Mr Hume gives the name of im- pressions to all our perceptions, to all our sensations, and even to the objects which we perceive. Mr Locke affirms very posi- tively, that the ideas of external objects are produced [96] in our minds by impulse, " that being the only way we can conceive bodies to operate in." It ought, however, to be observed, in justice to Mr Locke, that he retracted this notion in his first letter to the Bishop of Worcester, and promised, in the next edition of his Essay, to have that pas- sage rectified ; but, either from forgetful- ness in the author, or negligence in the printer, the passage remains in all the sub- sequent editions I have seen. There is no prejudice more natural to man than to conceive of the mind as hav- ing some similitude to body in its opera- tions. Hence men have been prone to imagine that, as bodies are put in motion by some impulse or impression made upon them by contiguous bodies, so the mind is made to think and to perceive by some im- pression made upon it, or some impulse given to it by contiguous objects. If we have such a notion of the mind as Homer had of his gods — who might be bruised or wounded with swords and spears— we may then understand what is meant by impres- sions made upon it by a body ; but, if we conceive the mind to be immaterial — of which I think we have very strong proofs — we shall find it difficult to affix a meaning to impressions made upon it. There is a figurative meaning of impres- sions on the mind which is well authorized, and of which we took notice in the observa- tions made on that word ; but this meaning applies only to objects that are interesting. To say that an object which I see with per- fect indifference makes an impression upon my mind, is not, as I apprehend, good English. If philosophers mean no more but that I see the object, why should they invent an improper phrase to express what every man knows how to express in plain English ? But it is evident, from the manner in which this phrase is used by modern philo- sophers, that they mean, not barely to ex- press by it my perceiving an object, but to explain the manner of perception. They think that the object perceived acts upon the mind in some way similar to that in which one body acts upon another, by making [97] an impression upon it. The impression upon the mind is conceived to be something wherein the mind is alto- gether passive, and has some effect pro- • A mere metaphor in Aristotle. (See Notes K and M.) At any rate, the imprr esion was supposed tn be made nn the animated sensor}, and not on the intellrct — H. duced in it by the object. But this is a hypothesis which contradicts the common sense of mankind, and which ought not to be admitted without proof. When I look upon the wall of my room, the wall does not act at all, nor is capable of acting ; the perceiving it is an act or operation in me. That this is the common apprehension of mankind with regard to perception, is evident from the manner of expressing it in all languages. The vulgar give themselves no trouble how they perceive objects — they express what they are conscious of, and they express it with propriety ; but philosophers have an avidity to know how we perceive objects ; and, conceiving some shnilitude between a body that is put in motion, and a mind that is made to perceive, they are led to think that, as the body must receive some impulse to make it move, so the mind must receive some impulse or impression to make it per- ceive. This analogy seems to be confirmed, by observing that we perceive objects only when they make some impression upon the organs of sense, and upon the nerves and brain ; but it ought to be observed, that such is the nature of body that it cannot change its state, but by some force impressed upon it. This is not the nature of mind. All that we know about it shews it to be in its nature living and active, and to have the power of perception in its constitution, but still within those limits to which it is confined by the laws of Nature. It appears, therefore, that this phrase of the mind's having impressions made upon it by corporeal objects in perception, is either a phrase without any distinct mean- ing, and contrary to the propriety of the English language, or it is grounded upon an hypothesis which is destitute of proof. On that account, though we grant that in perception there is an impression made upon the organ of [98] sense, and upon the nerves and brain, we do not admit that the object makes any impression upon the mind. There is another conclusion drawn from the impressions made upon the brain in perception, which I conceive to have no solid foundation, though it has been adopted very generally by philosophers. It is, that, by the impressions made on the brain, images are formed of the object perceived ; and that the mind, being seated in the brain as its chamber of presence, immediately perceives those images only, and has no perception of the external object but by them. This notion of our perceiving ex- ternal objects, not immediately, but in cer- tain images or species of them conveyed by the senses, seems to be the most ancient philosophical hypothesis we have on the subject of perception, and to have with [9G-98] CHAP. IV.] FALSE CONCLUSIONS, &c. 255 small variations retained its authority to this day. Aristotle, as was before observed, main- tained, that the species, images, or forms of external objects, coming from the object, are impressed on the mind. The followers of Democritus and Epicurus held the same thing, with regard to slender films of sub- tile matter coming from the object, that Aristotle did with regard to his immaterial species or forms. Aristotle thought every object of human understanding enters at first by the senses ;• and that the notions got by them are by the powers of the mind refined and spirit- ualized, so as at last to become objects of the most sublime and abstracted sciences. Plato, on the other hand, had a very mean opinion of all the knowledge we get by the senses. He thought it did not des'erve the name of knowledge, and could not be the foundation of science ; because the objects of sense are individuals only, 'and are in a constant fluctuation. All science, according to him, must be employed about those eternal and immutable ideas which existed before the objects of sense, and are not liable to any change. In this there was an essen- tial difference between the systems of these two philosophers. [99] The notion of eter- nal and immutable ideas, which Plato bor- rowed from the Pythagorean school, was totally rejected by Aristotle, who held it as a maxim, that there is nothing in the intel- lect, which was not at first in the senses. But, notwithstanding this great difference in those two ancient systems, they might both agree as to the manner in which we perceive objects by our senses : and that they did so, I think, is probable ; because Aristotle, as far as I know, neither takes notice of any difference between himself and his master upon this point, nor lays claim to his theory of the manner of our perceiving objects as his own invention. It is still more probable, from the hints which Plato gives in the seventh book of his Republic, concerning the manner in which we perceive the objects of sense ; which he compares to persons in a deep and dark cave, who see not external objects themselves but only their shadows, by a light let into the cave through a small opening, -f It seems, therefore, probable that the Py- thagoreans and Platonists agreed with the Peripatetics in this general theory of per- ception—to wit, that the objects of sense * This is a very doubtful point, and has accord- ingly divided his followers. Texts can be quoted to prove, on the one side, that Aristotle-derived all our notions, a posteriori, from the experience of sense ; and, on the other, that he viewed sense only as afford, ing to intellect the condition requisite for it to bo- come actually conscious of the native and necessary notions it, a priori, virtually possessed. — H. + Reid wholly mistakes the meaning of Plato's simile of the cave. See below, under p. 1 16. — H. [.99, 100] are perceived only by certain images, or shadows of them, let into the mind, as into a camera obscura. • The notions of the ancients were very various with regard to the seat of the soul Since it has been discovered, by the im- provements in anatomy, that the nerves are the instruments of perception, and of the sensations accompanying it, and that the nerves ultimately terminate in the brain,-)- it has been the general opinion of philosophers that the brain is the seat uf the soul ; and that she perceives the images that are brought there, and external things, only by means of them. Des Cartes, observing that the pineal gland is the only part of the brain that is single, all the other parts being double,^ and thinking that the soul must have one seat, was determined by this [100] to make that gland the soul's habitation, to which, by means of the animal spirits, intelligence is brought of all objects that affect the senses. § Others have not thought proper to con- fine the habitation of the soul to the pineal gland, but to the brain in general, or to some part of it, which they call the sen- sorium. Even the great Newton favoured this opinion, though he proposes it only as a query, with that modesty which dis- tinguished him no less than his great genius. "Is not," says he, " the sensorium of animals the place where the sentient substance is present, and to which the sensible species of things are brought through the nerves and brain, that there they may be perceived by the mind present in that place ? And is there not an incorporeal, living, intelligent, and omnipresent Being, who, in infinite space, as if it were in his sensorium, inti- mately perceives things themselves, and comprehends them perfectly, as being pre- sent to them ; of which things, that prin- ciple in us, which perceives and thinks, discerns only, in its little sensorium, the images brought to it through the organs of the senses ?"|| His great friend Dr Samuel Clarke adopted the same sentiment with more con- fidence. In his papers to Leibnitz, we find the following passages : " Without being present to the images of the things perceived, it (the soul) could not possibly perceive them. A lfviiig substanee can only there perceive where it is present, either to the things themselves, (as the omnipresent God is to the whole universe,) • An error. Sec below, under p. 1 IB.— H. + That is, since the time of Erasistratusand Galen. — H. } Which is not the case. The Hypophysis, the Vermiform process, &c, : re not less single than the Conarium. — H. § See above, p. 2:14, b, note * — H. |] Before Reid, these crude conjectures of Newton were justly censured by Gcnove.-i. and oLtier.. — H. 256 OM THE INTELLECTUAL POWERS. [essay II, or to the images of things, (as the soul of man is in its proper sensory.) Nothing can any more act, or be acted upon, where it is not present, than it can be where it is not. We are sure the soul cannot perceive what it is not present to, because nothing can act, or be acted upon, where it is not." Mr Locke expresses himself so upon this point, that, for the [101] most part, one would imagine that he thought that the ideas, or images of things, which he be- lieved to be the immediate objects of per- ception, are impressions upon the mind it- self ; yet, in some passages, he rather places them in the brain, and makes them to be perceived by the mind there present. " There are some ideas," says he, " which have admittance only through one sense ; and, if the organs or the nerves, which are the conduits to convey them from without to their audience in the brain, the mind's presence room, if I may so call it, are so disordered as not to perform their function, they have no postern to be admitted by. " There seems to be a constant decay of all our ideas, even of those that are struck deepest. The pictures drawn in our minds are laid in fading colours. "Whether the temper of the brain makes this difference, that in some it retains the characters drawn on it like marble, in others like freestone, and in others little better than sand, I shall not enquire."* From these passages of Mr Locke, and others of a like nature, it is plain that he thought that there are images of external objects conveyed to the brain. But whether he thought with Des Cartes^ and Newton, that the images in the brain are perceived by the mind there present, or that they are imprinted on the mind itself, is not so evi- dent. Now, with regard to this hypothesis, there are three things that deserve to be considered, because the hypothesis leans upon them ; and, if any one of them fail, it must fall to the ground. The first is, That the soul has its seat, or, as Mr Locke calls it, its presence room in the brain. The second, That there are images formed in the brain of all the objects of sense. The third, That the mind or soul perceives these images in the brain ; and that it perceives not external objects immediately, but only perceives them by means of those images. L102] As to the Jlrst point-^-that the soul has its * No great stress should be laid on such figurative passages as indications of the real opinion of .Locke, which, on this point, it is not easy to discover. See N-teO H. + Des Cartes is perhaps an erratum for Dr Clarke. If not, the opinion of Des Cartes is misrepresented ; for he denied to the mind all consciousness or imme- diate knowledge of matter and its modifications. But of this again, See Note N H. seat in the brain — this, surely, is not so well established as that we can safely build other principles upon it. There have been various opinions and -nuch disputation about the place of spirits : whether they have a place ? and, if they have, how they occupy that place ? After men had fought in the dark about those points for ages, the wiser part seem to have left off disputing about them, as matters beyond the reach of the human faculties. As to the second point — that images of all the objects of sense are formed in the brain — we may venture to affirm that there is no proof nor probability of this, with regard to any of the objects of sense ; and that, with regard to the greater part of them, it is words without any meaning." We have not the least evidence that the image of auy external object is formed in the brain. The brain has been dissected times innumerable by the nicest ana- tomists ; every part of it examined by the naked eye, and with the help of microscopes ; but no vestige of an image of any external object was ever found. The brain seems to be the most improper substance that can be imaginedfor receiving or retaining images, being a soft, moist, medullary substance. But how are these images formed ? or whence do they come ? Says Mr Locke, the organs of sense and nerves convey them from without. This is just the Aristotelian hypothesis of sensible species, which modern philosophers have been at great pains to refute, and which must be acknowledged to be one of the most unintelligible parts of the Peripatetic system. Those who con- sider species of colour, figure, sound, and smell, coming from the object, and entering by the organs of sense, as a part of the scholastic jargon long ago discarded from sound philosophy, ought to have discarded images in the brain along with them. There never was a shadow of argument brought by any author, to shew that an [103] image of any external object ever entered by any of the organs of sense. That external objects make some impres- sion on the organs of sense, and by them on the nerves and brain, is granted ; but that those impressions resemble the objects they are made by, so as that they may be called images of the objects, is most impro- bable. Every hypothesis that has been contrived, shews that there can be no such resemblance ; for neither the motions of animal spirits, nor the vibrations of elastic chords, or of elastic tether, or of theinfinites- * It 'would be rash to assume that, because a phi- losopher uses the term image, or impression, or idea, and places what it denotes in the brain, that he therefore means that the mind was cognisant of such corporeal affection, as ot its object, either in percep- tion or imagination. See Note K.— H. [101-103] OHAP. IV.] FALSE CONCLUSIONS, &c. 257 imal particles of the nerves, can be sup- posed to resemble the objects by which they are excited. We know that, in vision, an image of the visible object is formed in the bottom of the eye by the rays of light. But we know, also, that this image cannot be conveyed to the brain, because the optic nerve, and all the parts that surround it, are opaque and impervious to the rays of light ; and there is no other organ of sense in which any image of the object is formed. It is farther to be observed, that, with regard to some objects of sense, we may understand what is meant by an image of them imprinted on the brain; but, with regard to most objects of sense, the phrase is absolutely unintelligible, and conveys no meaning at all. As to objects of sight, I understand what is meant by an image of their figure in the brain. But how shall we conceive an image of their colour where there is absolute darkness ? And as to all other objects of sense, except figure and colour, I am unable to conceive what is meant by an image of them. Let any man say what he means by an image of heat and cold, an image of hardness or softness, an image of sound, or smell, or taste. The word image, when applied to these objects of sense, has abso- lutely no meaning. Upon what a weak foundation, then, does this hypothesis stand, when it supposes that images of all the objects of sense are imprinted on the brain, being conveyed thither by the conduits of the organs and nerves ! * [104] The third point in this hypothesis is, That the mind perceives the images in the brain, and external objects only by means of them. This is as improbable as that there are such images to be perceived. If our powers of perception be not altogether fallacious, the objects we perceive are not in our brain, but without us.-)- We are so far from perceiving images in the brain, that we do not perceive our brain at all ; nor would any man ever have known that he had a brain, if anatomy had not dis- covered, by dissection, that the brain is a constituent part of the human body. To sum up what has been said with re- gard to the organs of perception, and the impressions made upon our nerves and brain. It is a law of our nature, estab- lished by the will of the Supreme Being, that we perceive no external object but by * These objections to the hypothesis in question, have been frequently urged both in ancient and in modern tiroes. See Note K. — H. t If this be taken literally and by itself, then, ac- cording to Reid, perception is not an immanent cog- nition; extension and figure are, in that act, not merely suggested conceptions ; and, as we are perci- pientof the non-ego, and, consciousof the perception, we are therefore conscious of the non.ego. But 6ee Note C— H. £101, 105] means of the organs given us for that pur- pose. But these organs do not perceive. The eye is the organ of sight, but it sees not. A telescope is an artificial organ of sight. The eye is a natural organ of sight, but it sees as little as the telescope. We know how the eye forms a picture of the visible object upon the retina ; but how this picture makes us see the object we know not ; and if experience had not informed us that such a picture is necessary to vision, we should never have known it. We can give no reason why the picture on the re. tina should be followed by vision, while a like picture on any other part of the body produces nothing like vision. It is likewise a law of our nature, that we perceive not external objects, unless certain impressions be made by the object upon the organ, and by means of the organ upon the nerves and brain. But of the nature of those impressions we are perfectly ignorant ; and though they are conjoined with percep- tion by the will of our Maker, yet it does not appear that they have any necessary con- nection with it in their own nature, far less that they can be the proper efficient cause of it. [105] We perceive, because God has given us the power of perceiving, and not because we have impressions from objects. We perceive nothing without those impres- sions, because our Maker has limited and circumscribed our powers of perception, by such laws of Nature as to his wisdom seemed meet, and such as suited our rank in his creation.* * The doctrine of Reid and Stewart, in regard to our perception of external things, bears a close ana- logy to the Cartesian scheme of divine assistance, or of occasional causes It seems, however, to coincide most completely with the opinion of Ruardus Andala, a Dutch Cartesian, who attempted to reconcile the theory of assistance with that of physical infiuence "Statuo," he says, "nos clarissimam et distinctissimam hujus operationis et unionis posse habere ideam, si modo, quod omnino facere oportet, ad Deum, caus- sam ejus primam et liberam ascendamus, et ab ejus beneplacito admirandum nunc effectum derivemus. Nos possumus huic vel illi motui e. gr. campanas, sic et hederas suspensas literis scriptis, verbis quibus- cunque pronunciatie, aliisque signis, varias ideas alligare, ita, ut per visum, vel auditum in mente ex- citentur variee idea, perceptiones et sensationes .- annon hinc clare et facile intellijn'mus, Deum crea- toremm'ntis et corporiS'potuisse instituere et ordi. nare, ut per vaiios in corpore motus varias in mente excitentur ideas et perceptiones; et vicissim, ut pel varias mentis volitiones, varii in corpore excitentur ct producantur mctus r H nc et pro varia alter- utrius partis dispositione altera pars variis modis affici potest. Hoc autem a Deo ita ordinatum et effectum esse, a posteriori, continua, certissima et clarissima experientia docet Testes irrefragabiles omnique exceptione maj'ires reciproci hujus com- mercii, operationis mentis in corpus, et corporis in mentem, nee non communionis status, sunt tensus omnes turn externi, turn interni ; ut et omnes et singula? et continual actiones mentis in corp-s, de quibus modo fuit actum. Si quis vero a proprieta- tibus mentis ad proprietates corporis progredi velit, aut exraafarfldiversissimarum harum substantiarum deductre motum in corpore, & perceptiones in mente, aut hos effectus ut necessano connexns spectare ; nffi is frustra erit, nihil intelliget, perveisissimephi S 258 ON THE INTELLECTUAL POWERS. LESS A Y IU CHAPTER V. OP PEEOEPTION. In speaking of the impressions made on our organs in perception, we build upon facts borrowed from anatomy and physio- logy, for which we have the testimony of our senses. But, being now to speak of perception itself, which is solely an act of the mind, we must appeal to another authority. The operations of our minds are known, not by sense, but by conscious- ness, the authority of which is as certain and as irresistible as that of sense. In order, however, to our having a distinct notion of any of the operations of our own minds, it is not enough that we be conscious of them ; for all men have this consciousness. It is farther necessary that we attend to them while they are exerted, and reflect upon them with care, while they are recent and fresh in our memory. It is necessary that, by employing ourselves frequently in this way, we get the habit of this attention and reflec- tion ; and, therefore, for the proof of facts which I shall have occasion to mention upon this subject, I can only appeal to the reader's own thoughts, whether such facts are not agreeable to what he is conscious of in his own mind. [106] If, therefore, we attend to that act of our mind which we call the perception of an external object of sense, we shall find in it these three things : — First, Some con- ception or notion of the object perceived j Secondly, A strong and irresistible convic- tion and belief of its present existence ; and, Thirdly, That this conviction and belief are immediate, and not the effect of reasoning.* First, It is impossible to perceive an object without having some notion or con- ception of that which we perceive. We may, indeed, conceive an object which we do not perceive ; but, when we perceive the object, we must have some conception of it at the same time ; and we have commonly a more clear and steady notion of the object while we perceive it, than we have from memory or imagination when it is not per- ceived. Yet, even in perception, the notion which our senses give of the object may be more or less clear, more or less distinct, in all possible degrees. Thus we see more distinctly an object at a small than at a great distance. An object at a great distance is seen more distinctly in losophabitur nullamque hujus rei ideam habere po- tent. Si vero ad Deum Creatorem adscendamus, cumque vere agnoscamus, nihil hie erit obscuri, nunc effectual clarissime intelligemus, et quidem per eaussam ejus primam ; qua? perfectissima demum est scientia." — H. * See above, p. 183, a, noto < : p. 128. b, note » ; and Note C— H. a clear than in a foggy day. An object seen indistinctly with the naked eye, on account of its smallness, may be seen dis- tinctly with a microscope. The objects in this room will be seen by a person in the room less and less distinctly as the light of the day fails; they pass through all the various degrees of distinctness according to the degrees of the light, and, at last, in total darkness they are not seen at all. What has been said of the objects of sight is so easily applied to the objects of the other senses, that the application may be left to the reader. In a matter so obvious to every person capable of reflection, it is necessary only farther to observe, that the notion which we get of an object, merely by our external sense, ought not to be confounded with that more scientific notion which a man, come to the years of understanding, may have of the same object, by attending to its various attributes, or to its various parts, and their relation to each other, and to the whole. [107] Thus, the notion which a child has of a jack for roasting meat, will be acknowledged to be very different from that of a man who understands its construction, and perceives the relation of the parts to one another, and to the whole. The child sees the jack and every part of it as well as the man. The child, therefore, has all the notion of it which sight gives ; whatever there is more in the notion which the man forms of it, must be derived from other powers of the mind, which may afterwards be explained. This observation is made here only that we may not confound the operations of differ- ent powers of the mind, which by being always conjoined after we grow up to under- standing, are apt to pass for one and the same. Secondly, In perception we not only have a notion more or less distinct of the object perceived, but also an irresistible conviction and belief of its existence. This- is always the case when we are certain that we per- ceive it. There may be a perception so faint and indistinct as to leave us in doubt whether we perceive the object or not. Thus, when a star begins to twinkle as the light of the sun withdraws, one may, for a short time, think he sees it without being certain, until the perception acquire some strength and steadiness. When a ship just begins to appear in the utmost verge of the horizon, we may at first be dubious whether we perceive it or not ; but when the percep- tion is in any degree clear and steady, there remains no doubt of its reality ; and when the reality of the perception is ascertained, the existence of the object perceived can no longer be doubted.* • In this paragraph there is a confusion of that which is perceived and that which is inferred from the perception.— H. fl06. 1071 f-HAP. V.] OF PERCEPTION. 259 By the laws of all nations, in the most solemn judicial trials, wherein men's for- tunes and lives are at stake, the sentence passes according to the testimony of eye or ear witnesses of good credit. An upright judge will give a fair hearing to every objec- tion that can be made to the integrity of a witness, and allow it to be possible that he may be corrupted ; but no judge will ever suppose that witnesses maybe imposed upon by trusting to their eyes and ears. And if a sceptical counsel should plead against the testimony of the witnesses, that they had no other evidence for what they [108] de- clared but the testimony of their eyes and ears, and that we ought not to put so much faith in our senses as to deprive men of life or fortune upon their testimony, surely no upright judge would admit a plea of this kind. I believe no counsel, however scep- tical, ever dared to offer such an argument ; and, if it was offered, it would be rejected with disdain. Can any stronger proof be given that it is the universal judgment of mankind that the evidence of sense is a kind of evidence which we may securely rest upon in the most momentous concerns of mankind ; that it is a kind of evidence against which we ought not to admit any reasoning j and, therefore, that to reason either for or against it is an insult to common sense ? The whole conduct of mankind in the daily occurrences of life, as well as the so- lemn procedure of judicatories in the trial of causes civil and criminal, demonstrates this. I know only of two exceptions that may be offered against this being the uni- versal belief of mankind. The first exception is that of some luna- tics who have been persuaded of things that seem to contradict the clear testimony of their senses. It is said there have been lunatics and hypochondriacal persons, who seriously helieved themselves to be made of glass ; and, in consequence of this, lived in continual terror of having their brittle frame shivered into pieces. All I have to say to this is, that our minds, in our present state, are, as well as" our bodies, liable to strange disorders ; and, as we do not judge of the natural constitu- tion of the body from the disorders or dis- eases to which it is subject from accidents, so neither ought we to judge of the natural powers of the mind from its disorders, but from its sound state. It is natural to man, and common to the species, to have two hands and two feet ; yet I have seen a man, and a very ingenious one, who was born without either hands or feet. [109] It is natural to man to have faculties superior to those of brutes ; yet we see some indivi- duals whose faculties are not equal to those cf many brutes ; and the wisest man may, [108-110] by various accidents, be reduced to this state. General rules that regard those whose intellects are sound are not over- thrown by instances of men whose intellects are hurt by any constitutional or accidental disorder. The other exception that may be made to the principle we have laid down is that of some philosophers who have maintained that the testimony of sense is fallacious, and therefore ought never to be trusted. Perhaps it might be a sufficient answer to this to say, that there is nothing so absurd which some philosophers have not main- tained.* It is one thing to profess a doc- trine of this kind, another seriously to be- lieve it, and to be governed by it in the conduct of life. It is evident that a man who did not believe his senses could not keep out of harm's way an hour of his life ; yet, in all the history of philosophy, we never read of any sceptic that ever stepped into fire or water because he did not believe his senses, or that shewed in the conduct of life less trust in his senses than other men have.-f This gives us jnst ground to appre- hend that philosophy was never able to conquer that natural belief which men have in their senses ; and that all their subtile reasonings against this belief were never able to persuade themselves. It appears, therefore, that the clear and distinct testimony of our senses carries' irresistible conviction along with it to everj man in his right judgment. I observed, Thirdly, That this conviction is not only irresistible, but it is immediate that is, it is not by a train of reasoning and argumentation that we come to be convinced of the existence of what we perceive ; we ask no argument for the existence of the object, but that we per- ceive it ; perception commands our belief upon its own authority, and disdains to rest its authority upon any reasoning what- soever. J [110] The conviction of a truth may be irre- sistible, and yet not immediate. Thus, my conviction that the three angles of every plain triangle are equal to two right angles, is irresistible, but it is not immediate ; I am convinced of it by demonstrative rea- soning. There are other truths in mathe- matics of which we have not only an irre- sistible but an immediate conviction. Such are the axioms. Our belief of the axioms m mathematics is not grounded upon argu- * A saying of Varro. — H. t All this we read, however, in Laertius, of Pyrrho ; and on the authority of Antigonus Carystius, the great sceptic's contemporary. Whether we are to believe the narrative is another question.— H. X If Rcid holds that in perception we have only a conception of the Non.Ego in the Ego,-th\s iielief is either not the reflex of a cognition, but- a blind faith, or it is mediate, as held by Stewart.— Phiio;. Ess. ii c.2.— H. 62 260 ON THE INTELLECTUAL POWERS. [essay n. ment — arguments are grounded upon them ; but their evidence is discerned immediately by the human understanding. It is, no doubt, one thing to have an immediate conviction of a self-evident axiom ; it is another thing to have an im- mediate conviction of the existence of what we see ; but the conviction is equally imme- diate and equally irresistible in both cases. No man thinks of seeking a reason to believe what he sees ; and, before we are capable of reasoning, we put no less confidence in our senses than after. The rudest savage is as fully convinced of what he sees, and hears, and feels, as the most expert logician. The constitution of our understanding deter- mines us to hold the truth of a mathematical axiom as a first principle, from which other truths may be deduced, but it is deduced from none; and the constitution of our power of perception determines us to hold the existence of what we distinctly perceive as a first principle, from which other truths may be deduced ; but it is deduced fronK .fitted our powers of perception to this none. What has been said of the irresis- tible and immediate belief of the existence of objects distinctly perceived, I mean only to affirm with regard to persons so far ad- vanced in understanding as to distinguish objects of mere imagination from things which have a real existence. Every man knows that he may have a notion of Don Quixote, or of Garagantua, without any belief that such persons ever existed ; and that of Julius Caesar and Oliver Crom- well, he has not only a notion, but a belief that they did really exist. [Ill] But whether children, from the time that they begin to use their senses, make a distinction between things which are only conceived or imagined, and things which really exist, may be doubted. Until we are able to make this distinction, we cannot properly be said to believe or to disbelieve the existence of anything. The belief of the existence of anything seems to suppose a notion of existence — a notion too abstract, perhaps, to enter into the mind of an in- fant. I speak of the power of perception in those that are adult and of a sound mind, who believe that there are some things which do really exist ; and that there are many things conceived by themselves, and by others, which have no existence. That such persons do invariably ascribe existence to everything which they distinctly perceive, without seeking reasons or argu- ments for doing so, is perfectly evident from the whole tenor of human life. The account I have given of our percep- tion of external objects, is intended as a faithful delineation of what every man, come to years of understanding, and capable of giving attention to what passes in his own mind, may feel in himself. In what man- ner the notion of external objects, and the immediate belief of their existence, is pro- duced by means of our senses, I am not able to shew, and I do not pretend to shew. If the power of perceiving external objects in certain circumstances, be a part of the original constitution of the human mind, all attempts to account for it will be vain. No other account can be given of the con- stitution of things, but the will of Him that made them. As we can give no reason why matter is extended and inert, why the mind thinks and is conscious of its thoughts, but the will of Him who made both ; so I sus- pect we can give no other reason why, in certain circumstances, we perceive external objects, and in others do not.* The Supreme Being intended that we should have such knowledge of the material objects that surround us, as is necessary in order to our supplying the wants of nature, and avoiding the dangers to which we are constantly exposed ; and he has admirably purpose. [112] If the intelligence we have of external objects were to be got by reasoning only, the greatest part of men would be destitute of it ; for the greatest part of men hardly ever learn to reason ; and in infancy and childhood no man can reason : Therefore, as this intelligence of the objects that surround us, and from which we may receive so much benefit or harm, is equally necessary to children and to men, to the ignorant and to the learned, God in his wisdom conveys it to us in a way that puts all upon a level. The inform- ation of the senses is as perfect, and gives as full conviction to the most ignorant as to the most learned. CHAPTER VI. WHAT IT IS TO ACCOUNT FOB A PHENOMENON IN NAT DUB. An object placed at a proper distance, and in a good light, while the eyes are shut, is not perceived at all ; but no sooner do we open our eyes upon it than we have, as it were by inspiration, a certain knowledge of its existence, of its colour, figure, and distance. This is a fact which every one knows. The vulgar are satisfied with know- ing the fact, and give themselves no trouble about the cause of it : but a philosopher is impatient to know how this event is pro- duced, to account for it, or assign its cause. This avidity to know the causes of things is the parent of all philosophy, true and false. Men of speculation place a great part of their happiness in such knowledge. • See above.p. 128, b, note *,»niip. 130, b, note*: also Note A.— H. Till, 112] CHAP. VI.] Account op a phenomenon. 261 Felix qui potuit rerum cognoscere causas, has always been a sentiment of human nature. But, as in the pursuit of other kinds of happiness men often mistake the road, so in none have they more frequently done it than in the philosophical pursuit of the causes of things. [113] It is a dictate of common sense, that the causes we assign of appearances ought to be real, and not fictions of human imagina- tion. It is likewise self-evident, that such causes ought to be adequate to the effects that are conceived to be produced by them. That those who are less accustomed to inquiries into the causes of natural appear- ances, may the better understand what it is to shew the cause of such appearances, or to account for them, I shall borrow a plain instance of a phenomenon or appear- ance, of which a full and satisfactory ac- count has been given. The phaenomenon is this : That a stone, or any heavy body, falling from a height, continually increases its velocity as it descends ; so that, if it acquire a certain velocity in one second of time, it will have twice that velocity at the end of two seconds, thrice at the end of three seconds, and so on in proportion to the time. This accelerated velocity in a stone falling must have been observed from the beginning of the world ; but the first person, as far as we know, who accounted for it in a proper and philosophical manner, was the famous Galileo, after innumer- able false and fictitious accounts had been given of it. He observed, that bodies once put in motion continue that motion with the same velocity, and in the same direction, until they be stopped or retarded, or have the direction of their motion altered, by some force impressed upon them. This property of bodies is called their inertia, or inac- tivity; for it implies no more than that bodies cannot of themselves change their state from rest to motion, or from motion to rest. He observed also, that gravity acts constantly and equally upon a body, and therefore will give equal degrees of velocity to a body in equal times. From these principles, which are known from experi- ence to be fixed laws of nature, Galileo shewed that heavy bodies must descend with a velocity uniformly accelerated, as by experience they are found to do. [114] For if the body by its gravitation ac- quire a certain velocity at the end of one second, it would, though its gravitation should cease that moment, continue to go on with that velocity ; but its gravitation con- tinues, and will in another second give it an additional velocity, equal to that which it gave in the first ; so that the whole velocity at the end of two seconds, will be twice as great as at the end of one. In like manner, this pis-naT velocity being continued through the third second, and having the same addition by gravitation as in any of the preceding, the whole velocity at the end of the third second will be thrice as great as at the end of the first, and so on continually. We may here observe, that the causes assigned of this phsenomenou are two : First, That bodies once put in motion retain their velocity and their direction, until it is changed by some force impressed upon them. Se- condly, That the weight or gravitation of a body is always the same. These are laws of Nature, confirmed by universal experi- ence, and therefore are not feigned but true causes. Then, they are precisely adequate to the effect ascribed to them ; they must necessarily produce that very motion in descending bodies which we find to take place ; and neither more nor less. The account, therefore, given of this phsenom- non, is just and philosophical ; no other will ever be required or admitted by those who understand this. It ought likewise to be observed, that the causes assigned of this phenomenon, are things of which we can assign no cause. Why bodies once put in motion continue to move — why bodies constantly gravitate to- wards the earth with the same force — no man has been able to shew : these are facts confirmed by universal experience, and they must no doubt have a cause ; but their cause is unknown, and we call them laws of Nature, because we know no cause of them, but the will of the Supreme Being. But may we not attempt to find the cause of gravitation, and of other phsenomena, which we call laws of Nature ? No doubt wemay. [115] Weknownotthe limit which has been set to human knowledge, and our knowledge of the works of God can never be carried too far. But, supposing gravita- tion to be accounted for, by an sethereal elastic medium, for instance, this can only be done, first, by proving the existence and the elasticity of this medium ; and, secondly, by shewing that this medium must neces- sarily produce that gravitation which bodies are known to have. Until this be done, gravitation is not accounted for, nor is its cause known; and when this is done, the elasticity of this medium will be consi- dered as a law of nature whose cause is unknown. The chain of natural causes has, not unfitly, been compared to a chain hang- ing down from heaven : a link that is dis- covered supports the links below ifc, but it must itself be supported ; and that which supports it must be supported, until we come to the first link, which is supported by the throne of the Almighty. Every na- tural cause must have a cause, until we ascend to the first cause, which is uncaused, and operates not by necessity but by will 2b*2 ON THE INTELLECTUAL POWERS. [essay II. By what has been said in this chapter, those who are but little acquainted with philosophical inquiries, may see what is meant by accounting for a phsenomenon, or shewing its cause, which ought to be well understood, in order to judge of the theories by which philosophers have attempted to account for our perception of external ob- jects by the senses. CHAPTER VII. SENTIMENTS* op philosophers about the PERCEPTION OF EXTERNAL OBJECTS ; AND, FIRST, OF THE THEORY OF FATHER MALE- BRANCHE.*f How the correspondence is carried on between the thinking principle within us, and the material world without us, has always been found a very difficult problem to those philosophers who think themselves obliged to account for every phsenomenon in nature. [116] Many philosophers, ancient and modern, have employed their invention to discover how we are made to perceive ex- ternal objects by our senses ; and there appears to be a very great uniformity in their sentiments in the main, notwithstand- ing their variations in particular points. Plato illustrates our manner of perceiving the objects of sense, in this manner. He supposes a dark subterraneous cave, in which men lie bound in such a manner that they can direct their eyes only to one part of the cave : far behind, there is a light, some rays of which come over a wall to that part of the cave which is before the eyes of our prisoners. A number of per- sons, variously employed, pass between them and the light, whose shadows are seen by the prisoners, but not the persons them- selves. In this manner, that philosopher con- ceived that, by our senses, we perceive the shadows of things only, and not things themselves. He seems to have borrowed his notions on this subject, from the Pytha- goreans, and they very probably from Py- thagoras himself. If we make allowance for Plato's allegorical genius, his sentiments on this subject, correspond very well with • Sentiment, as here and elsewhere employed by Reid, in the meaning of opinion, (sententia,) is not to be imitated. There are, undoubtedly, precedents to be found for such usage in English writers ; and, In the French and Italian languages, this is one of the ordinary signflcations of the word.— H f It is not easy to conceive hy what principle the order of the history of opinions touching Perception, contained in the nine following chapters, is deter- mined. It is not chronological, and it is not systematic. Of these theories, there is a very able survey, by M. Royer t'ollard, among the fragments of his lectures, in the third volume of Jouffroy's " Oeuvres de Reid." That distinguished philosopher has, however, placed too great a reliance upon tt a accuracy of Reid — H. those of his scholar, Aristotle, and of the Peripatetics. The shadows of Plato may very well represent the species and phan- tasms of the Peripatetic school, and the ideas and impressions of modern philo- sophers.* * Thii interpretation of the meaning of Plato's comparison of the cave exhibits a curious mistake, in which Reid is followed by Mr Stewart and many others, and which, it is remarkable, has never yet been detected. In the similitude in question, (which will be found in the seventh book of the Republic,) Plato is supposed to intend an illustration of the mode in which the shadows or vicarious images of external things are admitted into the mind— to typify, in short, an hypothesis of sensitive perception. On this supposition, the identity of the Platonic, Pythagorean, and Peripatetic theories of this pro- cess is inferred. Nothing can, however, be more groundless than the supposition ; nothing more erro- neous than the inference. By his cave, images, and shadows, Plato meant simply to illustrate the grand principle of his philosophy — that the Sensible or Ec typal world, (phenomenal, transitory, ytyvofttvov, h *«* ,u.r, 6v,) stands to the Noetic or Archetypal, (sub- stantial, permanent, him h,) in the same relation of comparative unreality, in which the shadows of the images of sensible existences themselves, stand to the things of which they are the dim and distant adum- brations. In the language of an illustrious poet — " An nescis, quscunque heic sunt, qua; hac nocte teguntur, Cmnia res prorsus veras non esse, sed umbras, Aut specula, unde ad nos aliena elucet imago ? Terra quidem, et maria alta, atque his circumfluus aer, Etquse consistunt ex iis, haec omnia tenueis Sunt umbrae, humanos qua? tanquam sotnnia qute- dam Fertingunt animos, fallaci et imagine ludunt, Nunquam eadem, fluxu semper variata perenni, Sol autera, Luneque globus, fulgentiaque astra Ctetera, sint quamvis meliori praxlita vita, Et donata ffivo immortal i, haec ipsa tamen sunt .Xterni specula, in qua? animus, qui est inde profec tus, Inspiciens, patris quodam quasi tactus amore, Ardescit. Verum quoniam heic non perstat et ultra Nescio quid scquitur secum, tacitusque requirit, Nosse licet circum haec ipsum consistere verum, Non fin em : sed enim esse aliud quid, cujus imago Splendet in iis, quod per se ipsum est, et principium esse Omnibus sternum, ante omnem numerumque diem. que; In quo alium Solem atque aliam splendescere Lu- nam Adspicias, aliosque orbes, alia astra manere, Terramque, fluviosque alios, atque aera, et ignem, Et nemora, atque aliis erfare ammalia silvis." And as the comparison is misunderstood, so no- thing can be conceived more adverse to the doctrine of Plato than the theory it is supposed to elucidate. Plotinus, indeed, formally refutes, as contrary to the Platonic, the very hypothesis thus attributed to his master. (Enn. IV., 1. vi., cc. 1., 3.) The doctrineof the Flatonists on this point has been almost wholly neglected; and the author among them whose work contains its most articulate developement has been so completely overlooked, both by scholars and phi- losophers, that his work is of the rarest, while even his name is mentioned in no history of philosophy. It is here sufficient to state, that the t'&tvXa., thu koyoi yvwrtKol, the forms representative of external things, and corresponding to the species sensiles ex- press* of the schoolmen, were not held by the Plato, nists to be derived from without. Prior to the at t ol perception, they have a latent but real existence in the soul ; and, by the impassive energy of the mind itself, are elicited into consciousness, on occasion of the impression (xiyv l {ri$,x&8oe i Eu$*iris)rn&fieontheex.teT. nal organ, and of the vital form {turtxov ilios), in con- sequence thereof, sublimated in the animal life. The verses of Boethius, which have been so frequently misunderstood, contain an accurate statement of the Platonic theory of perception. After refuting the 1 116") Chap, vii.] SENTIMENTS ABOUT PERCEPTION. 263 Two thousand years after Plato, Mr Locke, who studied the operations of the human mind so much, and with so great success, representsourmanner of perceiving external objects,, by a similitude very much resembling that of the cave. , " Methinks," says he, "the understanding is not much unlike a closet wholly shut from light, with only some little opening left, to let in exter- nal visible resemblances or ideas of things without. Would the pictures coming into such a dark room but stay there, and lie so orderly as to be found upon occasion, it would very much resemble the under- standing of a man, in reference to all objects of sight, and the ideas of them. " [117] Plato's subterranean cave, and Mr Locke's dark closet, may be applied with ease to all the systems of perception that have been invented : for they all suppose that we perceive not external objects immediately, and that the immediate objects of percep- tion are only certain shadows of the ex- ternal objects. Those shadows or images, which we immediately perceive, were by the ancients called species, forms, phan- tasms. Since the time of Des Cartes, they have commonly been called ideas, and by Mr Hume, impressions. But all philoso- phers, from Plato to Mr Hume, agree in this, That we do not perceive external ob- jects immediately, and that the immediate object of perception must be some image present to the mind.* So far there ap- Stoical doctrine of the passivity of mind in this pro- cess, he proceeds : — " Mens est efficiena magis Longe causa potentior, Quam quee materia; modo lmpressas patitur notas. Prcecedit tamen excitant Ac vires animi movens Vivo in corpore passio. Cum vel lux oculos ferit, Vel vox auribus instrepit: Turn mentis'yigor excitus Quas inius species tenet, Ad motus similes vocans, Notis applicat exteris, Introrsumque recondiiis Formis miscet imagines." I cannot now do more than indicate the contrast of this doctrine to the Peripatetic (I do not say Aris- totelian) theory, and its approximation to the Carte- sian and Leibnitzian hypotheses ; which, however, both attempt to explain, what the Platonic did not— how the mind, ex hypothesi, above all physical in- fluence, is determined, on the presence of the un- known reality within the sphere of sense, to call into consciousness the representation through which that reality is made known to us. I may add, that not merely the Platonists, but some of the older Peripa- tetics held that the soul virtually contained within it- self representative forms, which were only excited by the external reality ; as Theophrastus and The- mistius, to say nothing of the Platonizing Porphyry, Simplicius and Ammonius Hermia? ; and the same opinion, adopted probably from the latter, by his pupil, the Arabian Adelandus, subsequently be- came even the common doctrine of the Moorish Aristotelians. I shall afterwards have occasion to notice that Bacon has also wrested Plato's similitude of the cave from its genuine signification — H. * This is not correct. There were philosophers pears an unanimity, rarely to be found among philosophers on such abstruse points.* If it should be asked, Whether, accord- ing to the opinion of philosophers, we per- ceive the images or ideas only, and infer the existence and qualities of the external ob- ject from what we perceive in the image ; or, whether we really perceive the external object as well as its image ? — the answer to this question is not quite obvious, -f- On the one hand, philosophers, if we ex- cept Berkeley and Hume, believe the ex- istence of external objects of sense, and call them objects of perception, though not im- mediate objects. But what they mean by a mediate object of perception I do not find clearly explained : whether they suit their language to popular opinion, and mean that we perceive external objects in that figura- tive sense in which we say that we perceive an absent friend when we look on his pic- ture ; or whether they mean that, really, and without a figure, we perceive both the external object and its idea in the mind. If the last be their meaning, it would follow that, in every instance of perception, there is a, double object perceived: [118] that I perceive, for instance, one sun in the heavens, and another in my own mind.J But I do not find that they affirm this ; and, as it contradicts the experience of all mankind, I will not impute it to them. It seems, therefore, that their opinion is, That we do not really perceive the external object, but the internal only ; and that, when they speak of perceiving external objects, they mean it only in a popular or in a figur- ative sense, as above explained. Several reasons lead me to think this to be the opinion of philosophers, beside what is mentioned above. First, If we do really perceive the external object itself, there seems to be no necessity, no use, for an image of it. Secondly, Since the time of Des Cartes, philosophers have very gene- rally thought that the existence of external objects of sense requires proof, and can only be proved from the existence of their ideas. Thirdly, The way in which philosophers speak of ideas, seems to imply that they are the only objects of perception. who held a purer and preciser doctrine of immediate perception than Reid himself contemplated. — H. * Reid himself, like the philosophers in general, really holds, that we do not perceive external tilings immediately, if he does not allow us a consciousness of the non-ego. It matters nnt whether the external reality be represented in a tertium quid, or in a mo- dification of the mind itself; in either case, it is not known in itself, but in something numerically dif- ferent.— H. t Nothing can be clearer than wouldbe this answer. In perception, the external reality, (the mediate object,} is only known to us in and through the im- mediate object, i. e., the representation of which we are conscious. As existing, and beyond the 6phere of consciousness, the external reality is unknown — H. 1 " Et solem geminum et duplices se ostendere Thebas!"— H. [117, 118] 264 ON THE INTELLECTUAL POWERS. [essay n. Having endeavoured to explain what is common to philosophers in accounting for our perception of external objects, we shall give some detail of their differences. The ideas by which we perceive external objects, are said by some to be the ideas of the Deity ; but it has been more generally thought, that every man's ideas are proper to himself, and are either in his mind, or in his sensorium, where the mind is imme- diately present. The first is the theory of Malebranche ; the second we shall call the common theory. With regard to that of Malebranche, it seems to have some affinity with the Pla- tonic notion of ideas,* but is not the same. Plato believed that there are three eternal first principles, from which all things have their origin — matter, ideas, and an efficient cause. Matter is that of which all things are made, which, by all the ancient philo- sophers, was conceived to be eternal. [119] Ideas are forms without matter of every kind of things which can exist ; which forms were also conceived by Plato to be eternal and immutable, and to be the models or patterns by which the efficient cause — that is, the Deity — formed every part of this universe. These ideas were conceived to be the sole objects of science, and indeed of all true knowledge. While we are im- prisoned in the body, we are prone to give attention to the objects of sense only ; but these being individual things, and in a con- stant fluctuation, being indeed shadows rather than realities, cannot be the object of real knowledge. All science is employed not about individual things, but about things universal and abstract from matter. Truth is eternal and immutable, and there- fore must have for its object eternal and immutable ideas ; these we are capable of contemplating in some degree even in our present state, but not without a certain purification of mind, and abstraction from the objects of sense. Such, as far as I am able to comprehend, were the sublime notions of Plato, and probably of Pytha- goras. The philosophers of the Alexandrian school, commonly called the latter Plato- nists, seem to have adopted the same sys- tem ; but with this difference, that they made the eternal ideas not to be a principle distinct from the Deity, but to be in the divine intellect, as the objects of those con- ceptions which the divine mind must, from all eternity, have had, not only of every- • The Platonic theory of Ideas has nothing to do with a doctrine of sensitive perception ; and its intro- duction into the question is only pregnant with con- fusion ; while, in regard to sensitive perception, the peculiar hypothesis of Malebranche, is in fact not only not similar to, but much farther removed from, the Platonic than the common Cartesian theory, and the Leibnitzian — H. thing which he has made, but of every pos- sible existence, and of all the relations of things.* By a proper purification and abstraction from the objects of sense, we may be in some measure united to the Deity, and, in the eternal light, be enabled to discern the most sublime intellectual truths. These Platonic notions, grafted upon Christianity, probably gave rise to the sect called Mystics, which, though in its spirit and principles extremely opposite to the Peripatetic, yet was never extinguished, but subsists to this day. [120] Many of the Fathers of the Christian church have a tincture of the tenets of the Alexandrian school ; among others, St Augustine. But it does not appear, as far as I know, that either Plato, or the latter Platonists, or St Augustine, or the Mystics, thought that we perceive the objects of sense in the divine ideas. They had too mean a notion of our perception of sensible objects to ascribe to it so high an origin. This theory, therefore, of our perceiving the objects of sense in the ideas of the Deity, I take to be the invention of Father Malebranche himself. He, indeed, brings many passages of St Augustine to counte- nance it, and seems very desirous to have that Father of his party. But in those passages, though the Father speaks in a very high strain of God's being the light of our minds, of our being illuminated imme- diately by the eternal light, and uses other similar expressions ; yet he seems to apply those expressions only to our illumination in moral and divine things, and not to the perception of objects by the senses. Mr Bayle imagines that some traces of this opinion of Malebranche are to be found in Amelius the Platonist, and even in Demo- critus; but his authorities seem to be strained.-f- Malebranche, with a very penetrating genius, entered into a more minute examin- ation of the powers of the human mind, than any one before him. He had the advan- tage of the discoveries made by Des Cartes, whom he followed without slavish attach- ment. He lays it down as a principle admitted by all philosophers, and which could not be called in question, that we do not per- ceive external objects immediately, but by means of images or ideas of them present to the mind. " I suppose," says he," that * And this, though Aristotle asserts the contrary, was perhaps also the doctrine of Plato. — H. f The theory of Malebranche has been vainly sought for in the Bible, the Platonists, and the Fathers. It is, in fact, more clearly enounced mi Homer than in any of these graver sources. To~6f yag via is-h srtxdoviuv ocvd^troiVt OTov esr' ii/teif ofyy,iri ir«T»jfi aySf £v Tl dtaiv T8. But for anticipations, see Note P.— H. [119, 120"] chap. vn.J SENTIMENTS ABOUT EXTERNAL OBJECTS. 265 every one will grant that we perceive not the objects that are without us immediately, and of themselves. • We see the sun, the stars, and an infinity of objects without us ; and it is not at all likely that the soul sal- lies out of the body, and, as it were, takes a walk through the heavens, to contemplate all those objects. [121] She sees them not, therefore, by themselves ; and the imme- diate object of the mind, when it sees the sun, for example, is uot the sun, but some- thing which is intimately united to the soul ; and it is that which I call an idea. So that by the word idea, I understand nothing else here but that which is the im- mediate object, or nearest to the mind, when we perceive-|- any object.$ It ought to be carefully observed, that, in order to the mind's perceiving any object, it is abso- lutely necessary that the idea of that ob- ject be actually present to it. Of this it is not possible to doubt The things which the soul perceives are of two kinds. They are either in the soul, or they are without the soul. Those that are in the soul are its own thoughts — that is to say, all its different modifications. [For by these words — thought, manner of think- ing, or modification of the soul, I under- stand in general whatever cannot be in the mind without the mind perceiving it, as its proper sensations, its imaginations, its pure intellections, or simply its conceptions, its passions even, and its natural inclina- tions. ]§ The soul has no need of ideas for perceiving these things. || But with regard to things without the soul, we cannot per- ceive them but by means of ideas."^f Having laid this foundation, as a prin- ciple common to all philosophers, and which admits of no doubt, he proceeds to enume- rate all the possible ways by which the ideas of sensible objects may be presented to the mind : Either, first, they come from the bodies which we perceive ;* • or, secondly, the soul has the power of producing them in it- self ;ff or, thirdly, they are produced by the • Rather in or by themselves (par eux mimes.) -H. t That is, in the language of philosophers before Reid, *' where we have the apprehensive cognition or consciousness of any object."— H. t In this definition, all philosophers concur. Des Cartes, Locke, &c, give it in almost the same terms. -H. \ I have inserted this sentence, omitted by Reid, from the original, in order to shew in how exten- sive a meaning the term thought was used in the Cartesian school. See Cartesii Princ, P. I., \ 9. — H. || Hence the distinction precisely taken by Male- branche of Idea (idte) and Feeling, (sentiment,) cor- responding in principle to our Perception of the primary, and our Sensation of the secondary qualities. H be la Recherche de la Veriti. Liv. III., Partie ii., ch. I.— H. • • The common Peripatetic doctrine, &c.— H. ■ff Malebranche refers, I presume, to the opinions of certain Cartesians. See Gassendi Opera, iii. p 321. — H. [121, 122] Deity, either in our creation, or occasionally, as there is use for them ;" or, fourthly, the soul has in itself virtually and eminently, as the schools speak, all the perfections which it perceives in bodies ;+ or, fifthly, the soul is united with a Being possessed of all per- fection, who has in himself the ideas of all created things. This he takes to be a complete enumera- tions of all the possible ways in which the ideas of external objects may be presented to our minds. He employs a whole chapter upon each ; refuting the four first, and con- firming the last by various arguments. The Deity, being always present to our minds in a more intimate manner than any other being, may, upon occasion of the im- pressions made on our bodies, discover to us, as far as he thinks proper, and according to fixed laws, his own ideas of the object ; and thus we see all things in God, or in the divine ideas.:}: [122] However visionary this system may ap- pear on a superficial view, yet, when we consider that he agreed with the whole tribe of philosophers in conceiving ideas to be the immediate objects of perception, and that he found insuperable difficulties, and even absurdities, in every other hypothesis con- cerning them, it will not appear so wonder- ful that a man of very great genius should fall into this ; and, probably, it pleased so devout a man the more, that it sets, in the most striking light, our dependence upon God, and his continual presence with us. He distinguished, more accurately than any philosopher had done before, the objects which we perceive from the sensations in our own minds, which, by the laws of Nature, always accompany the perception of the object. As in many things, so par- ticularly in this, he has great merit. For this, I apprehend, is a key that opens the way to a right understanding, both of our external senses and of other powers of the mind. The vulgar confound sensation with other powers of the mind, and with their objects, because the purposes of life do not make a distinction necessary. The con- founding of these in common language, has led philosophers, m one period, to make those things external which really are sens- ations in our own minds ; and, in another period, running, as is usual, into the con- • Opinions analogous to the second or third, were held by the Platonists, by some of the Greek, and by many of the Arabian Aristotelians. See .-.bove, p. 262, note •.— H. + Something similar to this is hazarded by Des Cartes in his Third " Meditation," which it is likely that Malebranche had in his eye.— H. % It should have been noticed that the Malebranch- ian philosophy is fundamentally Cartesian, and that, after De la Forge and Geulinx, the doctrine of Divine Assistance, implicitly maintained by Des Cartes, was most ably developed by Malebranche, to whom it owes, >ndeed, a principal share of its eel- brity.— H. 266 ON THE INTELLECTUAL POWERS. [essay It trary extreme, to make everything almost to be a sensation or feeling in our minds. It is obvious that the system of Male- branche leaves no evidence of the existence of a material world, from what we perceive by our senses ; for the divine ideas, which are the objects immediately perceived, were the same before the world was created. Malebranche was too acute not to discern this consequence of his system, and too can- did not to acknowledge it. [123] Hefairly owns it, and endeavours to make advantage of it, resting the complete evidence we have of the existence of matter upon the author- ity of revelation. He shews that the argu- ments brought by Des Cartes to prove the existence of a material world, though as good as any that reason could furnish, are not perfectly conclusive ; and, though he acknowledges with Des Cartes that we feel a strong propensity to believe the existence of a material world, yet he thinks this is not sufficient ; and that to yield to such propensities without evidence, is to expose ourselves to perpetual delusion. He thinks, therefore, that the only convincing evidence we have of the existence of a material world is, that we are assured by revelation that God created the heavens and the earth, r and that the Word was made flesh. He is sensible of the ridicule to which so strange an opinion may expose him among those who are guided by prejudice ; but, for the sake of truth, he is willing to bear it. But no author, not even Bishop Berkeley, hath shewn more clearly, that, either upon his own system, or upon the common principles of philosophers with regard to ideas, we have no evidence left, either from reason or from our senses, of the existence of a material world. It is no more than justice to Father Malebranche, to acknowledge that Bishop Berkeley's arguments are to be found in him in their whole force. Mr Norris, an English divine, espoused the syBtem of Malebranche, in his " Essay towards the Theory of the Ideal or Intel- Jectual World," published in two volumes 8°, anno 1701. This author has made a feeble effort to supply a defect which is to be found not in Malebranche only, but in almost all the authors who have treated of ideas— I mean, to prove their existence.* He has employed a whole chapter to prove that material things cannot be an immediate object of perception. His arguments are these : Is*, They are without the mind, and, therefore there can be no union between the object and the perception. 2dly, They are disproportioned to the mind, and removed * This is incorrect. In almost every system of the Aristotelico-scholastic philosophy, the attempt is made to prove the existence of Species ; nor is Reid's asset tinn true even of ideas in the Cartesian philoso- phy. In fact, Norris's arguments are all old and commonplace.*- H. from it by the whole diameter of being. Sdly, Because, if material objects were immediate objects of perception, there could be no physical science; things necessary and immutable being the only objects of science. [124] ilhlp, If material things were perceived by themselves, they would be a true light to our minds, as being the intel- ligible form of our understandings, and con- sequently perfective of them, and, indeed, superior to them. Malebranche's system was adopted by many devout people in France of both sexes ; but it seems to have had no great currency in other countries. Mr Locke wrote a small tract against it, which is found among his posthumous works :* but, whether it was written in haste, or after the vigour of his understanding was im- paired by age, there is less of strength and solidity in it than in most of his writings. The most formidable antagonist Male- branche met with was in his own country — Antony Arnauld, doctor of the Sorbonne, and one of the acutest writers the Jansenists have to boast of, though that sect has pro- duced many. Malebranche was a Jesuit, and the antipathy between the Jesuits and Jansenists left him no room to expect quarterfrom hislearnedantagonist.-|- Those who choose to see this system attacked on the one hand, and defended on the other, with subtilty of argument and elegance of expression^ and on the part of Arnauld with much wit and humour, may find satis- faction by reading Malebranche's " Enquiry after Truth ;" Arnauld's book " Of True and False Ideas ;" Malebranche's " Defence ;" and some subsequent replies and defences. In controversies of this kind, the assailant commonly has the advantage, if they are not unequally matched ; for it is easier to overturn all the theories of philosophers upon this subject, than to defend any one of them. Mr Bayle makes a very just re- mark upon this controversy — that the argu- ments of Mr Arnauld against the system of Malebranche, were often unanswerable, but * In answer to Locke's " Examination of P. Male- branche's Opinion," Leibnitz wrote " Remarks," which are to be found among his posthumous works, published by Raspe. — H. t Malebranche was not a Jesuit, but a Priest of the Oratory; and so little was he either a favourer or favourite of the Jesuits, that, by the Pere de Valois, he was accused of heresy, by the Pere Hardouin, of Atheism. The endeavours of the Jesuits in France to prohibit the introduction of every form of the Carte- sian doctrine into the public seminaries of education, are well known. Malebranche and Arnauld were therefore not opposed as Jesuit and Jansenist, and it should likewise be remembered that they were both Cartesians. — H. t Independently of his principal hypothesis alto- gether, the works of Malebranche deserve the most attentive study, both on account of the many ad. mirable thoughts and observations with which they abound, and because they are among the few con. summate models of philosf phical eloquence — H. ns3, 124,3 ufcAf. vm/j OF THE THEORY OF PERCEPTION, &c. 261 they were capable of being retorted against his own system ; and his ingenious antag- onist knew well how to use this defence. [.125] CHAPTER VIII. OF THE COMMON THEORY OP PERCEPTION, AND OF THE SENTIMENTS OF THE PERIPA- TETICS, AND OF DES CARTES. This theory, in general, is, that we per- ceive external objects only by certain images which are in our minds, or in the sensorium to which the mind is immediately present. Philosophers in different ages have differed both in the names they have given to those images, and in their notions concerning them. It would be a laborious task to enumerate all their variations, and per- haps would not requite the labour. I shall only give a sketch of the principal dif- ferences with regard to their names and their nature. By Aristotle and the Peripatetics, the images presented to our senses were called sensible species or forms ; those presented to the memory or imagination were called phantasms ; and those presented to the intellect were called intelligible species ; and they thought that there can be no perception, no imagination, no intellection, without species or phantasms," What the ancient philosophers called species, sensible and intelligible, and phantasms, in later times, and especially since the time of Des Cartes, came to be called by the common name of ideas. -(• The Cartesians divided our ideas into three classes — those of sensa- tion, of imagination, and of pure intellection. Of the objects of sensation and imagination, they thought the images are in the brain ;% but of objects that are incorporeal the images are in the understanding or pure intellect. Mr Locke, taking the word idea in the same sense as Des Cartes had done before him, to signify whatever is meant by phan- tasm, notion, or species, divides ideas into those of sensation, and those of reflection ; meaning by the first, the ideas of all corpo- real objects, whether perceived, remem- bered, or imagined; by the second, the ideas of the powers and operations of our minds. [126] What Mr Locke calls ideas, Mr Hume divides into two distinct kinds, impressions and ideas. The difference be- twixt these, he says, consists in the degrees of force and liveliness with which they strike upon the mind. Under impressions he com- prehends all our sensations, passions, and • See Note SI.— H. I Not merely especially, but only since the time of Del Cartes, See Note G.— H. t incorrect. See Note N.— H. £125, 126] emotions, as they make their first appear- ance in the soul. By ideas, he means the faint images of these in thinking and rea- soning. Dr Hartley gives the same meaning to ideas as Mr Hume does, and what Mr Hume calls impressions he calls sensations ; conceiving our sensations to be occasioned by vibrations of the infinitesimal particles of the brain, and ideas by miniature vibra- tions or vibratiuncles. Such differences we find among philosophers, with regard to the name of those internal images of objects of sense which they hold to be the imme- diate objects of perception." We shall next give a short detail of the sentiments of the Peripatetics and Carte- sians, of Locke, Berkeley, and Hume, con- cerning them. Aristotle seems to have thought that the soul consists of two parts, or rather that we have two souls — the animal and the ra- tional ; or, as he calls them, the soul and the intellect, f To the first, belong the senses, memory, and imagination ; to the last, judgment, opinion, belief, and reason- ing. The first we have in common with brute animals ; the last is peculiar to man. The animal soul he held to be a certain form of the body, which is inseparable from it, and perishes at death. To this soul the senses belong ; and he defines a sense to be that which is capable of receiving the sensi- ble forms or species of objects, without any of the matter of them ; as wax receives the form of the seal without any of the matter of it. The forms of sound, of colour, of * Reid, I may observe in general, does not dis. tinguislvas it especially behoved him to do, between what were held by philosophers to be the proximate causes of our mental representations, and these representations themselves as'the objects of cognition — i. e , between what are known in the schools as thespecies impressa, and the species express^. The former, to which the name of sfjecies, image, idea, was often given, in common with the latter, was held on all hands to be unknown to consciousness, and generally supposed to be merely certain occult motions in the organism. -The latter, the result determined by the former, is the mental representation, and the immediate or proper object in perception. Great confusion, to those who do not bear this distinction in mind, is, however, the consequence of the verbal ambiguity; and Reid'a misrepresentations of the doctrine of the philosophers its, in a great measure, to be traced to this source. — H. + This not correct. Instead nftwo, the animal and rational, Aristotle gave to the soul three generic functions, the vegetable, the animal or sensual, and the rational; but whether he supposes these to constitute three concentric potences, three separate parts, or three distinct souls, has divided his disciples. He also defines the soul ingenerai, and not, as Reid supposes, the mere * animal soul,' to be the form or ivTeAfouat of the body. — {De .-lnimal.il. c I.) In- tellect [vis) he however thought was inorganic; but there is some ground for believing that he did not view this as personal, but harboured an opinion which, under various modifications, many of his fol lowers also held, that the active intellect was com- mon to all men, immortal and divine. Km? yu e treat sr&yru, to iv fipgi 0«« * \iryou X x$z*l J" Aoyoff iAA* n xeiiTrt)*, 77 ouv Sit KEiirrov xeii ttrifij/Mlf UXOI, akr,t Qtcei — H. 268 Ott THE INTELLECTUAL POWERS. Qessay li taste, and of other sensible qualities, are, in manner, received by the senses. " [127] It seems to be a necessary consequence of Aristotle's doctrine, that bodies are con- stantly sending forth, in all directions, as many different kinds of forms without matter as they have different sensible qua- lities ; for the forms of colour must enter tey the eye, the forms of sound by the ear, and so of the other senses. This, accord- ingly, was maintained by the followers of Aristotle, though not, as far as I know, expressly mentioned by himself. •)- They disputed concerning the nature of those forms of species, whether they were real beings or nonentities ;$ and some held them to be of an intermediate nature be- tween the two. The whole doctrine of the Peripatetics and schoolmen concerning forms, substantial and accidental, and con- cerning the transmission of sensible species from objects of sense to the mind, if it be at all intelligible, is so far above my com- prehension that I should perhaps do it in- justice, by entering into it more minutely. Malebranche, in his " Eecherche de la Verite," has employed a chapter to shew that material objects do not send forth sensible species of their several sensible qualities. The great revolution which Des Cartes produced in philosophy, was the effect of a superiority of genius, aided by the circum- stances of the times. Men had, for more than h. thousand years, looked up to Ari- stotle as an oracle in philosophy. His authority was the test of truth. The small remains of the Platonic system were con- fined to a few mystics, whose principles and manner of life drew little attention. The feeble attempts of Ramus, and of some others, to make improvements in the sys- tem, had little effect. The Peripatetic doctrines were so interwoven with the whole system of scholastic theology, that to dissent from Aristotle was to alarm the Church. The most useful and intelligible parts, even of Aristotle's writings, were neglected, and philosophy was become an art of speak- ing learnedly, and disputing subtilely, with- out producing any invention of use in human life. It was fruitful of words, but barren of works, and admirably contrived for drawing a veil over human ignorance, and • See Note M.— H. f Nor is there valid ground for supposing that such an opinion was even implicitly held by the Stagirite. It was also explicitly repudiated by many of his fol. lowers. See Note M. — H. t The question in the schools, between those who admitted species, was not, whether species, in gene, ral, were real beings or nonentities (which would have been, did they exist or not,) but whether sen- si le species were material, immaterial, or of a nature between body and spi it — a problem, it must b ' allowed, sufficiently futile, but not, like the other, self- contradictory. — H. putting a stop to the progress of knowledge, by filling men with a conceit that they knew everything. [128] It was very fruitful also in controversies ; but, for the most part, they were controversies about words, or about things of no moment, or things above the reach of the human faculties. And the issue of them was what might be expected — that the contending parties fought, without gaining or losing an inch of ground, till they were weary of the dispute, or their atten- tion was called off to some other subject.* Such was the philosophy of the schools of Europe, during many ages of darkness and barbarism that succeeded the decline of the Roman empire; so that there was great need of a reformation in philosophy as well as in religion. The light began to dawn at last ; a spirit of inquiry sprang up, and men got the courage to doubt of the dogmas of Aristotle, as well as of the decrees of Popes. The most important step in the reformation of religion, was to destroy the claim of infallibility, which hindered men from using their judgment in matters of religion ; and the most important step in the reformation of philosophy, was to destroy the authority of which Aristotle had so long had peaceable possession. The last had been attempted by Lord Bacon and others, with no less zeal than the first by Luther aud Calvin. Des Cartes knew well the defects of the prevailing system, which had begun to lose its authority. His genius enabled him, and his spirit promp'ted him, to attempt a new one. He had applied much to the mathe- matical sciences, and had made considerable improvement in them. He wished to in- troduce that perspicuity and evidence into other branches of philosophy which he found in them. Being sensible how apt we are to be led astray by prejudices of education, he thought the only way to avoid error was to resolve to doubt of everything, and hold everything to be uncertain, even those things which he had been taught to hold as most certain, until he had such clear and cogent evidence as compelled his assent. [129] In this state of universal doubt, that which first appeared to him to be clear and certain, was his own existence. Of this he was certain, because he was conscious that he thought, that he reasoned, and that he doubted. He used this argument, there- fore, to prove his own existence, Cagito, ergo sum. This he conceived to be the first of all truths, the foundation-stone upon which the whole fabric of human knowledge * This is the vulgar opinion in regard to the scholastic philosophy. The few are, however, now aware that the human mind, though partially, was never more powerfully developed than during the middle ages.— H. ["127-129] »ihap. vni.] OF THE THEORY OF PERCEPTION, &c. 269 is built, and on which it must rest.* And, as Archimedes thought that, if he had one fixed point to rest his engines upon, he could move the earth ; so Des Cartes, charmed with the discovery of one certain principle, hy which he emerged from the state of universal doubt, believed that this principle alone would be a sufficient found- ation on which he might build the whole system of science. He seems, therefore, to have taken no great trouble to examine whether there might not be other first prin- ciples, which, on account of their own light and evidence, ought to be admitted by every man of sound judgment. -j- The love of simplicity so natural to the mind of man, led him to apply the whole force of his mind to raise the fabric of knowledge upon this one principle, rather than seek a broader foundation. Accordingly, he does not admit the evi- dence of sense to be a first principle, as he does that of consciousness. The argu- ments of the ancient sceptics here occurred to him, that our senses often deceive us, and therefore ought never to be trusted on their own authority : that, in sleep, we often seem to see and hear things which we are convinced to have had no existence. But that which chiefly led Des Cartes to think that he ought not to trust to his senses, without proof of their veracity, was, that he took it for granted, as all philosophers had done before him, that he did not perceive external objects themselves, but certain images of them in his own mind, called ideas. He was certain, by consciousness, that he had the ideas of sun and moon, earth and sea ; but how could he be assured that there really existed external objects like to these ideas ?% [130] Hitherto he was uncertain of everything but of his own existence, and the existence of the operations and ideas of his own mind. Some of his disciples, it is said, remained at this stage of his system, and got the name of Egoists. § They could not find evidence in the subsequent stages of his progress. But Des Cartes resolved not to stop here ; he endeavoured to prove, by a new argu- ment, drawn from his idea of a Deity, the existence of an infinitely perfect Being, who made him and all his faculties. From the perfection of this Being, he inferred that he could be no deceiver ; and therefore con- cluded that his senses, and the other facul- ties he found in himself, are not fallacious, • On the Cartesian doubt, see Note R. — H. t This cannot justly be affirmed of Des Cartes. -H t On this point it is probable that Des Cartes and Beid are at one. See Notes C and N — H. 6 I am doubtful about the existence of this sup- posed sect of Egoists. The Chevalier Ramsay, above a century ago, incidentally speaks of this doc trine as an offshoot of Spinolism, and under the but may be trusted, when a proper use is made of them. The system of Des Cartes is, with great perspicuity and acuteness, explained by himself in his writings, which ought to he consulted by those who would understand it. The merit of Des Cartes cannot be easily conceived by those who have not some notion of the Peripatetic system, in which he was educated. To throw off the preju- dices of education, and to create a system of nature, totally different from that which had subdued the understanding of mankind, and kept it in subjection for so many cen. turies, required an uncommon force of mind. The world which Des Cartes exhibits to our view, is not only in its structure very different from that of the Peripatetics, but is, as we may say, composed of different materials. In the old system, everything was, by a kind of metaphysical sublimation, resolved into principles so mysterious that it may be a question whether they were words with- out meaning, or were notions too refined for human understanding. All that we observe in nature is, accord- ing to Aristotle, a constant succession of the operations of generation and corruption, [131 ] The principles of generation are mat- ter and form. The principle of corruption is privation. All natural things are produced or generated by the union of matter and form ; matter being, as it were, the mother, and form the father. As to matter, or the first matter, as it is called, it is neither substance nor accident ; it has no quality or property ; it is nothing actually, but everything potentially. It has so strong an appetite for form, that it is no sooner divested of one form than it is clothed with another, and is equally susceptible of all forms successively. It has no nature, but only the capacity of having any one. This is the account which the Peripate- tics give of the first matter. The other principle of generation is form, act, perfec- tion; for these three words signify the same thing. But we must not conceive form to consist in the figure, size, arrangement, or motion of the parts of matter. These, in- deed, are accidental forms, by which things name of Egomisme. But Father Burner, about the same time, and, be it noted, in a work published some ten years before Hume's " Treatise of Human Na- ture," talks of it, on hearsay, as the speculation of a Scotch philosopher :— " Un ecrivain Ecossois apublie, dit on, un ouvragepour prouverqu'il n'avoit aucune evidence de l'existence d'aucun etre que de lui ; et encore de lui, en tant qu' esprit; n'aiant aucune de- monstration veritable de l'existence d'aucun corps." —Ekmens de Metaphysique, 4 61. Now, we know that there is no such work. I am aware, however, that there is some discussion on this point'in the " Memoirs de Trevoux," anno 1713, p.922 ; to which however, I mast refer the reader, as I have not that journal at hand —But more of this below, undei p 187.— H. [130, 13Q 'J70 ON THE INTELLECTUAL POWERS. [essay ij. artificial are formed : but every production of Nature has a substantial form,* which, joined to matter, makes it to be what it is. The substantial form is a kind of informing soul, which gives the thing its specific na- ture, and all its qualities, powers, and activity. Thus the substantial form of heavy bodies, is that which makes them descend ; of light bodies, that which makes them ascend. The substantial form of gold, is that which gives it its ductility, its fusibility, its weight, its colour, and all its qualities ; and the same is to be understood of every natural production. A change in the accidental form of any body, is alteration only ; but a change in the substantial form is generation and corruption : it is corrup- tion with respect to the substantial form, of which the body is deprived ; it is genera- tion with respect to the substantial form that succeeds. Thus, when a horse dies and turns to dust, the philosophical account of the phaenomenon is this : — A certain por- tion of the materia prima, which was joined to the substantial form of a horse, is de- prived of it by privation, and in the same instant is invested with the substantial form of earth. [132] As every substance must have a substantial form, there are some of those forms inanimate, some vegetative, some animal, and some rational. The three former kinds can only subsist in matter ; but the last, according to the schoolmen, is immediately created by God, and infused into the body, making one substance with it, while they are united; yet capable of being disjoined from the body, and of sub- sisting by itself. Such are the principles of natural things in the Peripatetic system. It retains so much of the ancient Pythagorean doctrine, that we cannot ascribe the invention of it solely to Aristotle, although he, no doubt, made considerable alterations in it. The first matter was probably the same in both sys- tems, and was in both held to be eternal. They differed more about form. The Py- thagoreans and Platonists held forms or ideas, as they called them, to be eternal, immutable, and self-existent. Aristotle maintained that they were not eternal, nor self-existent. On the other hand, he did not allow them to be produced, but educed from matter ; yet he held them not to be actually in the matter from which they are educed, but potentially only. But these two systems differed less from one another, than that of Des Cartes did from both. In the world of Des Cartes we meet with two kinds of beings only — to wit, body and mind ; the first the object of our senses, * It is not. however, to be supposed that the scholastic doctrine of Substantial Forms receives any countenance from the authority of Aristotle, if we lav aside his language touching the soul. — H. the other of consciousness ; both of them things of which we have a distinct appre- hension, if the human mind be capable of distinct apprehension at all. To the first, no qualities are ascribed but extension, figure, and motion ; to the last, nothing but thought, and its various modifications, of which we are conscious." He could ob- serve no common attribute, no resembling feature, in the attributes of body and mind, and therefore concluded them to be distinc* substances, and totally of a different nature ; and that body, from its very nature, is in- animate and inert, incapable of any kind of thought or sensation, or of producing any change or alteration in- itself. [138] Des Cartes must be allowed the honour of being the first who drew a distinct line between the material and intellectual world, which, in all the old systems, were so blended together that it was impossible to say where the one ends and the other be- gins.-)- How much this distinction hath contributed to the improvements of modern times, in the philosophy both of body and of mind, is not easy to say. One obvious consequence of this distinc- tion was, that accurate reflection on the operations of our own mind is the only way to make any progress in the knowledge of it. Malebranche, Locke, Berkeley, and Hume, were taught this lesson by Des Cartes ; and to it we owe their most va- luable discoveries in this branch of philo- sophy. The analogical way of reasoning concerning the powers of the mind from the properties of body, which is the source of almost all the errors on this subject, and which is so natural to the bulk of mankind, was as contrary to the principles of Des Cartes, as it was agreeable to the princi- ples of the old philosophy. We may there- fore truly say, that, in that part of philoso- phy which relates to the mind, Des Cartes laid the foundation, and put us into that tract which all wise men now acknowledge to be the only one in which we can expect success. With regard to physics, or the philosophy of body, if Des Cartes had not the merit of leading men into the right tract, we must allow him that of bringing them out of a wrong one. The Peripatetics, by assigning to every species of body a particular sub- stantial form, which produces, in an un- known manner, all the effects we observe in it, put a stop to all improvement in this branch of philosophy. Gravity and levity, fluidity and hardness, heat and cold, were qualities arising from the substantial form of the bodies to which they belonged. Gen- • In the Cartesian language, the term thought in- cluded all of which we are conscious.— H. + This assertion is true in general ; but some in. dividual exceptions might be taken.— H. [ 132, 133") chap, viii.] OF THE THEORY OF PERCEPTION, &c. 271 eration and corruption, substantial forms and occult qualities, were always at hand, to resolve every phenomenon. This phi- losophy, therefore, instead of accounting for any of the phsenomena of Nature, con- trived only to give learned names to their unknown causes, and fed men with the husks of barbarous terms, instead of the fruit of real knowledge. [134] By the spreading of the Cartesian system, materia prima, substantial forms, and oc- cult qualities, with all the jargon of the Aristotelian physics, fell into utter disgrace, and were never mentioned by the followers of the new system, but as a subject of ridi- cule. Men became sensible that their un- derstanding had been hoodwinked by those hard terms. They were now accustomed to explain the phenomena of nature, by the figure, size, and motion of the particles of matter, things perfectly level to human understanding, and could relish nothing in philosophy that was dark and unintelligible. Aristotle, after a reign of more than a thousand years, was now exposed as an objectof derision even to the vulgar, arrayed in the mock majesty of his substantial forms and occult qualities. The ladies became fond of a philosophy which was easily learned, and required no words too harsh for their delicate organs. Queens and princesses, the most distinguished personages of the age, courted the conversation of Des Cartes, and became adepts in his philosophy. Wit- uess Christina, Queen of Sweden, and Elizabeth, daughter of Frederick, King of Bohemia, the mother of our Royal Family. The last, though very young when Des Cartes wrote his " Principia," he declares to be the only person he knew, who per- fectly understood not only all his philoso- phical writings, but the most abstruse of his mathematical works. That men should rush with violence from one extreme, without going more or less into the contrary extreme, is not to be ex- pected from the weakness of human nature. Des Cartes and his followers were not ex- empted from this weakness ; they thought that extension, figure, and motion, were sufficient to resolve all the phsenomena of the material system. To admit other qua- lities, whose cause is unknown, was to return to Egypt, from which they had been so happily delivered. [135] When Sir Isaac Newton's doctrine of gravitation was published, the great objec- tion to it, which hindered its general recep- tion in Europe for half a century, was, that gravitation seemed to be an occult quality, as it could not be accounted for by exten- sion, figure, and motion, the known attri- butes of body. They who defended him found it difficult to answer this objection to the satisfaction of those who had been [134-1361 initiated in the principles of the Cartesian system. But, by degrees, men came to be sensible that, in revolting from Ari- stotle, the Cartesians had gone into the oppo- site extreme ; experience convinced them that there are qualities in the material world, whose existence is certain though their cause be occult. To acknowledge this, is only a candid confession of human ignor- ance, than which there is nothing more be- coming a philosopher. As all that we can know of the mind must be derived from a careful observation of its operations in ourselves ; so all that we can know of the material system must be derived from what can be discovered by our senses, Des Cartes was not ignorant of this ; nor was his system so unfriendly to observation and experiment as the old system was.* He made many experiments, and called earnestly upon all lovers of truth to aid him in this way ; but, believing that all the phsenomena of the material world are the result of extension, figure, and motion, and that the Deity always combines these, so as to produce the phsenomena in the simplest manner possible, he thought that, from a few experiments, he might be able to dis- cover the simplest way in which the obvious phsenomena of nature can be produced by matter and motion only ; and that this must be the way in which they are actually pro- duced. His conjectures were ingenious, upon the principles he had adopted ; but they are found to be so far from the truth, that they ought for ever to discourage philosophers from trusting to conjecture in the operations of nature. [136] The vortices or whirlpools of subtile matter by which Des Cartes endeavoured to account for the phsenomena of the ma- terial world, are now found to be fictions, no less than the sensible species of Ari- stotle, -f- It was reserved for Sir Isaac Newton to point out clearly the road to the knowledge of nature's works. Taught by Lord Bacon to despise hypotheses as the fictions of hu- man fancy, he laid it down as a rule of philosophising, that no causes of natural things ought to be assigned but such as can be proved to have a real existence. He saw that all the length men can go in ac- counting for phsenomena, is to discover the laws of nature according to which they are produced; and, therefore, that the true method of philosophising is this : From real facts, ascertained by observation and experiment, to collect by just induction the • That is, the Aristotelic. But Aristotle himself was as declared an advocate of experiment as any philosopher ; and it is not to be imputed to him that his authority had subsequently the effect of imped, ing, by being held to supersede, observation. — H. f Read *'the sensible species of the schoolmen. * See Note M.— H. 272 ON THE INTELLECTUAL POWERS. ["essay II, laws of Nature, and to apply the laws so discovered, to account for the phenomena of Nature. Thus, the natural philosopher has the rules of his art fixed with no less precision than the mathematician, and may be no less certain when he keeps within them, and when he deviates from them. And, though the evidence of a law of nature from induc- tion is not demonstrative, it is the only kind of evidence on which all the most import- ant affairs of human life must rest. Pursuing this road without deviation, Newton discovered the laws of our planet- ary system, and of the rays of light ; and gave the first and the noblest examples of that chaste induction which Lord Bacon could only delineate in theory. How strange is it that the human mind should have wandered for so many ages, without falling into this tract ! How much more strange, that, after it has been clearly discovered, and a happy progress made in it, many choose rather to wander in the fairy regions of hypothesis ! [137] To return to Des Cartes's notions of the manner of our perceiving external objects, from which a concern to do justice to the merit of that great reformer in philosophy has led me to digress, he took it for granted, as the old philosophers had done, that what we immediately perceive must be either in the mind itself, or in the brain, to which the mind is immediately present. The im- pressions made upon our organs, nerves, and brain could be nothing, according to his philosophy, but various modifications of extension, figure, and motion. There could be nothing in the brain like sound or colour, taste or smell, heat or cold ; these are sens- ations in the mind, which, by the laws of the union of soul and body, are raised on occasion of certain traces in the brain ; and although he gives the name of ideas to those traces in the brain, he does not think it necessary that they should be perfectly like to the things which they represent, any more than that words or signs should resemble the things they signify. But, says he, that we may follow tne received opinion as far as is possible, we may allow a slight resemblance. Thus we know that a print in a book may represent houses, temples, and groves ; and so far is it from being necessary that the print should be perfectly like the thing it represents, that its perfection often requires the contrary : for a circle must often be represented by an ellipse, a square by a rhombus, and so of other things." * But be it observed that Des Cartes did not allow. Tar less hold, that the mind had any cognizance of these organic motions— of these material ideas They were merely tlie antecedents, established by the law of union, of themental idea : which mental idea was no- The perceptions of sense, he thought, are to be referred solely to the union of soul and body. They commonly exhibit to us only what may hurt or profit our bodies ; and rarely, and by accident only, exhibit things as they are in themselves. It is by observing this, that we must learn to throw off the prejudices of sense, and to attend with our intellect to the ideas which are by nature implanted in it. By this means we shall understand that the nature of matter does not consist in those things that affect our senses, such as colour, or smell, or taste ; but only in this, that it is something ex- tended in length, breadth, and depth. [138] The writings of Des Cartes have, in ge- neral, a remarkable degree of perspicuity ; and he undoubtedly intended that, in this particular, his philosophy should be a per- fect contrast to that of Aristotle ; yet, in what he has said, in different parts of his writings, of our perceptions of external objects, there seems to be some obscurity, and even inconsistency ; whether owing to his having had different opinions on the sub- ject at different times, or to the difficulty he found in it, I will not pretend to say. There are two points, in particular, wherein I cannot reconcile him to himself : the first, regarding the place of the ideas or images of external objects, which are the immediate objects of perception ; the second. with regard to the veracity of our external senses. As to the first, he sometimes places the ideas of material objects in the brain, not only when they are perceived, but when they are remembered or imagined; and this has always been held to be the Car- tesian doctrine;* yet he sometimes says, that we are not to conceive the images or traces in the brain to be perceived, as if there were eyes in the brain ; these traces are only occasions on which, by the laws of the union of soul and body, ideas are ex cited in the mind ; and, therefore, it is not necessary that there should be an exact resemblance between the traces and the things represented by them, any more than that words or signs should be exactly like the things signified by them.-|- These two opinions, I think, cannot be reconciled. For, if the images or traces in the brain are perceived,} they must be the thing more than a modification of the mind itself.— H. * But not in Reid's exclusive sense of the word Idea.— H. t The non-negation, in this instance, of all re- semblance between the material Ideas, or organic motions in the brain, and the external reality, is one of the occasional instances of Des Cartes's reticence of his subordinate doctrines, in order to avoid all useless tilting against prevalent opinions. Another is his sometimes giving to these motions the name of Spe- cies.— H. $ Which, in Des Cartes' doctrine, they arc not.— H. ["137, 1381 chap, viii.] OF THE THEORY OF PERCEPTION, &c. 273 objects of perception, and not the occasions of it only. On the other hand, if they are only the occasions of our perceiving, they are not perceived at all. Des Cartes seems to have hesitated between the two opinions, or to have passed from the one to the other.* Mr Locke seems, in like manner, to have wavered between the two ; some- times representing the ideas of material things as being in the brain, but more fre- quently as in the mind itself, -f- [139] Neither Des Cartes nor Mr Locke could, consistently with themselves, attribute any other qualities to images in the brain but extension, figure, and motion ; for as to those qualities which Mr Locke distin- guished by the name of secondary qualities, both philosophers believed them not to be- long to body at all,$ and, therefore, could not ascribe them to images in the brain. § Sir Isaac Newton and Dr Samuel Clarke uniformly speak of the species or images of material things as being in that part of the brain called the sensorium, and perceived by the mind there present ; but the former speaks of this point only incidentally, and with his usual modesty, in the form of a query. || Malebranche is perfectly clear and unambiguous in this matter. According to his system, the images or traces in the brain are not perceived at all — they are only occasions upon which, by the laws of Nature, certain sensations are felt by us, and certain of the divine ideas discovered to our minds. The second point on which Des Cartes seems to waver, is with regard to the credit that is due to the testimony of our senses. Sometimes, from the perfection of the Deity, and his being no deceiver, he infers that our senses and our other faculties can- not be fallacious ; and since we seem clearly to perceive that the idea of matter comes to us from things external, which it per- fectly resembles, therefore we must con- clude that there really exists something extended in length, breadth, and depth, having all the properties which we clearly perceive to belong to an extended thing. At other times, we find Des Cartes and his followers making frequent complaints, • Des Cartes had only one opinion on the point. The difficulty which perplexes Reid arose from his want of a systematic comprehension of the Cartesian philosophy, and his being unaware that, by Ideas, Des Cartes designated two very different things— vif., the proximate bodily antecedent, and the mental consequent.— H. f Locke's opinion, if he had a precise one on the matter, it is impossible to ascertain. See Note O — H. t See above, p. 205, note * — H. § Yet Locke expressly denies them to be modifica- tions of mind. See Note O — H. || Reid is correct in all he here says of Newton and Clarke j it u indeed virtually admitted by Clarke himself, in his controversy wiih Leibnitz. Compare Leibnitii Opera, II., p. 161, and p. 18s! — H. ["139, HO] as all the ancient philosophers did, of the fallacies of sense. He warns us to throw off its prejudices, and to attend only with our intellect, to the ideas implanted there. By this means we may perceive, that the nature of matter does not consist in hard- ness, colour, weight, or any of those things that affect our senses, but in this only, that it is something extended in length, breadth, and depth. [140] The senses, he says, are only relative to our present state ; they exhibit things only as they tend to profit or to hurt us, and rarely, and by accident only, as they are in themselves. * It was probably owing to an aversion to admit anything into philosophy, of which we have not a clear and distinct concep- tion, that Des Cartes was led to deny that there is any substance of matter distinct from those qualities of it which we perceive.-)- We say that matter is something extended, figured, moveable. Extension, figure, mo- bility, therefore, are not matter, but quali- ties, belonging to this something, which we call matter. Des Cartes could not relish this obscure something, which is sup- posed to be the subject or substratum of those qualities ; and, therefore, maintained that extension is the very essence of mat- ter. But, as we must ascribe extension to space as well as to matter, he found him- self under a necessity of holding that space and matter are the same thing, and differ only in our way of conceiving them ; so that, wherever there is space there is mat- ter, and no void left in the universe. The necessary consequence of this is, that the material world has no bounds nor limits. He did not, however, choose to call it in- finite, but indefinite. It was probably owing to the same cause that Des Cartes made the essence of the soul to consist in thought. He would not allow it to be an unknown something that has the power of thinking ; it cannot, there- fore, be without thought ; and, as he con- ceived that there can be no thought with- out ideas, the soul must have had ideas in its first formation, which, of consequence, are innate. $ The sentiments of those who came after Des Cartes, with regard to the nature of body and mind, have been various. Many have maintained that body is only a collec- tion of qualities to which we give one • But see " Principia," $ 66, sqq.— H. t See Stewart's " Elements," I., Note A ; Royer Collard's Fragment, VIII.— H. t The doctrine of Des Cartes, in relation to lunate Ideas, has been very generally misunderstood ; and by no one more than by Locke. What it really amounted to, is clearly stated in his strictures on the Program of Regius. Justice has latterly been done him, among others, by Mr. Stewart, in his " Dis. sertation," and by M. Laiomiguiere, in his " Cours." See also the old controversy ot De Vries with Hue]] on this point. — H. 274 ON THE INTELLECTUAL POWERS. [essav II. name ; and that the notion of a subject of inhesion, to which those qualities belong, is only a fiction of the mind.* [141] Some hare even maintained that the sonl is only a succession of related ideas, with- out any subject of inhesion. + It appears, by what has been said, how far these no- tions are allied to the Cartesian system. The triumph of the Cartesian system over that of Aristotle, is one of the most remarkable revolutions in the history of phi- losophy, and has led me to dwell longer upon it than the present subject perhaps required. The authority of Aristotle was now no more. That reverence for hard words and dark notions, by which men's understanding had been strangled in early years, was turned into contempt, and every- thing suspected which was not clearly and distinctly understood. This is the spirit of the Cartesian philosophy, and is a more important acquisition to mankind than any of its particular tenets; and for exerting this spirit so zealously, and spreading it so successfully, Des Cartes deserves immortal honour. It is to be observed, however, that Des Cartes rejected a part only of the ancient theory, concerning the perception of ex- ternal objects by the senses, and that he adopted the other part. That theory may be divided into two parts : The first, that images, species, orforms of externalobjects, come from the object, and enter by the avenues of the senses to the mind; the second part is, That the external object itself is not perceived, but only the species or image of it in the mind. The first part Des Cartes and his followers rejected, and refuted by solid arguments ; but the second part, neither he nor his followers have thought of calling in question ; being per- suaded that it is only a representative image in the mind of the external object that we perceive, and not the object itself. And this image, which the Peripatetics called a species, he calls an idea, changing the name only, while he admits the thing. J [142] It seems strange that the great pains which this philosopher took to throw off the prejudices of education, to dismiss all his former opinions, and to assent to nothing, till he found evidence that compelled his assent, should not have led him to doubt of this opinion of the ancient philosophy. It is evidently a philosophical opinion ; for the vulgar undoubtedly believe that it is the * As Locke, (but he Is not consistent,) Law, Green, Watts, and others. See Cousin, " Cours de Philosophic," Tome II., Legem xviii. — H. t Hume— H X Des Cartes and Beid coincide in doctrine, if Reid holds that we know the extended and exter- nal object only, by a conception or subjective modifi- tion of the percipient mind. See Notes N and C. — H. external object which we immediately per- ceive, and not a representative image of it only. It is for this reason that they look upon it as perfect lunacy to call in question the existence of external objects.* It seems to be admitted as a first. prin- ciple, by the learned and the unlearned, that what is really perceived must exist, and that to perceive what does not exist is impossible. So far the unlearned man and the philoso- pher agree. The unlearned man says — I perceive the external object, and I perceive it to exist. Nothing can be more absurd than to doubt of it. The Peripatetic says — What I perceive is the very identical form of the object, which came immediately from the object, and makes an impression upon my mind, as a seal does upon wax ; and, therefore, I can have no doubt of the ex- istence of an object whose form I perceive. ■(■ But what says the Cartesian ? I perceive not, says he, the external object itself. So far he agrees with the Peripatetic, and differs from the unlearned man. But I perceive an image, or form, or idea, in my own mind, or in my brain. I am certain of the existence of the idea, because I imme- diately perceive it--f- But how this idea is formed, or what it represents, is not self- evident; and therefore I must find argu- ments by which, from the existence of the idea which I perceive, I can infer the ex- istence of an external object which it re- presents. As I take this to be a just view of the principles of the unlearned man, of the Peri- patetic, and of the Cartesian, so I think they all reason consequentially from their several principles : that the Cartesian has strong grounds to doubt of the existence of external objects ; the Peripatetic very little ground of doubt ; and the unlearned [143] man none at all : and that the difference of their situation arises from this — that the un- learned man has no hypothesis ; the Peri- patetic leans upon an hypothesis ; and the Cartesian upon one half of that hypothesis. Des Cartes, according to the spirit of his own philosophy, ought to have doubted of both parts of the Peripatetichypothesis, or to have given his reasons why he adopted one part, as well as why he rejected the other * This is one of the passages which favour the opinion that Reid did suppose the non-ego to be known in itself as existing, and not only in and through the ego ; tor mankind in general believe that the extended reality, as perceived, is something more than a mere internal representation by the mind, suggested in consequence of the impression made by an unknown something on the sense. See Note C— H. f The Peripatetic and the Cartesian held that the species or idea was an object of consciousness. If Reid understood the language he uses, he must bold that the external and extended reality is an object of consciousness. But this does not quadrate with his doctrine, that we only know extension and figure by a suggested conception in the mind. See Note C— H. [14.1-143"] chap, ix.] OF THE SENTIMENTS OF MR LOCKE. 275 part ; especially, since the unlearned, who have the faculty of perceiving objects by their senses in no less perfection than philosophers, and should, therefore, know, as well as they, what it is they perceive, have been unanimous in this, that the objects they perceive are not ideas in their own minds, but things external. It might have been expected that a philosopher who was so cautious as not to take his own ex- istence for granted without proof, would not have taken it for granted without proof, that everything he perceived was only ideas in his own mind. But, if Des Cartes made a rash step in this, as I apprehend he did, he ought not to bear the blame alone. His successors have still continued in the same track, and, after his example, have adopted one part of the ancient theory — to wit, that the objects we immediately perceive are ideas only. All their svstems are built on this foundation. CHAPTER IX. OF THE SENTIMENTS OF ME LOCKE. The reputation which Locke's " Essay on Human Understanding" had at home from the beginning, and which it has gradually acquired abroad, is a sufficient testimony of its merit. [144] There is, perhaps, no book of the metaphysical kind that has been so generally read by those who understand the language, or that is more adapted to teach men to think with precision,* and to inspire them with that candour and love of truth which is the genuine spirit of philo- sophy. He gave, I believe, the first ex- ample in the English language of writing on such abstract subjects, with a remarkable degree of simplicity and perspicuity ; and in this he has been happily imitated by others that came after him. No author hath more successfully pointed out the danger of ambiguous words, and the im- portance of having distinct and determin- ate notions in judging and reasoning. His observations on the various powers of the human understanding, on the use and abuse of words, and on the extent and limits of human knowledge, are drawn from atten- tive reflection on the operations of his own mind, the true source of all real knowledge on these subjects ; and shew an uncommon degree of penetration and judgment. But he needs no panegyric of mine, and I men- tion these things, only that, when I have occasion to differ from him, I may not be thought insensible of the merit of an author whom I highly respect, and to whom I owe * To praise Locke for precision, is rather too much— H. [144, 145] my first lights in those studies, as well as my attachment to them. He sets out in his essay with a full con- viction, common to him with other philo- sophers, that ideas in the mind are the objects of all our thoughts in every opera- tion of the understanding. This leads him to use the word idea" so very frequently, beyond what was usual in the English language, that he thought it necessary, in his introduction, to make this apology : — " It being that term,'' says he, " which, I I think, serves best to stand for whatsoever is the object of understanding when a man thinks, I have used it to express whatever is meant by phantasm, notion, species, or whatever it is which the mind can be em- ployed about in thinking ; and I could not avoid frequently using it. I presume it will be granted me, that there are such ideas in men's minds ; every man is con- scious of them in himself, and men's words and actions will satisfy him that they are in others." [145] Speaking of the reality of our knowledge, he says, " It is evident the mind knows not things immediately, but only by the inter- vention of the ideas it has of them. Our knowledge, therefore, is real, only so far as there is a conformity between our ideas and the reality of things. But what shall be here the criterion ? How shall the mind, when it perceives nothing but its own ideas, know that they agree with things them- selves ? This, though it seems not to want difficulty, yet, I think, there be two sorts of ideas that we may be assured agree with things." We see that Mr Locke was aware, no less than Des Cartes, that the doctrine of ideas made it necessary, and at the same time difficult, to prove the existence of a material world without us; because the mind, according to that doctrine, perceives nothing but a world of ideas in itself. Not only Des Cartes, but Malebranche, Arnauld, and Norris, had perceived this difficulty, and attempted to remove it with little suc- cess. Mr Locke attempts the same thing ; but his arguments are feeble. He even seems to be conscious of this ; for he con- cludes his reasoning with this observation — " That we have evidence sufficient to direct us in attaining the good and avoiding the evil, caused by external objects, and that this is the important concern we have in being made acquainted with them." This, indeed, is saying no more than will be granted by those who deny the existence of a material world. As there is no material difference between * Locke may be said to have first naturalized the ward in English philosophical language, in its Caite- sian extension. — H. T 2 276 ON THE INTELLECTUAL POWERS. [essay II. Locke and Des Cartes with regard to the perception of objects by the senses, there is the less occasion, in this place, to take notice of all their differences in other points- They differed about the origin of our ideas. Des Cartes thought some of them were innate ; the other maintained that there are no innate ideas, and that they are all derived from two sources — to wit, sensation and reflection ; meaning, by sensation, the operations of our exterrfal senses ; and, by reflection, that attention which we are capable of giving to the operations of our own minds. [146] They differed with regard to the essence both of matter and of mind : the British philosopher holding that the real essence of both is beyond the reach of human know- ledge ; the other conceiving that the very essence of mind consists in thought, and that of matter in extension, by which he made matter andspacenottodifferin reality, and no part of space to be void of matter. Mr Locke explained, more distinctly than had been done before, the operations of the mind in classing the various objects of thought, and reducing them to genera and species. He was the first, I think, who distinguished in substances what he calls the nominal essence — which is only the notion we form of a genus or species, and which we express by a definition — from the real essence or internal constitution of the thing, which makes it to be what it is.* Without this distinction, the subtile dis- putes which tortured the schoolmen for so many age's, in the controversy between the nominalists and realists, could never be brought to an issue. He shews distinctly how we form abstract and general notions, and the use and necessity of them in rea- soning. And as (according to the received principles of philosophers) every notion of our mind must have for its object an idea in the mind itself, -|- he thinks that we form abstract ideas by leaving out of the idea of an individual everything wherein it differs from other individuals of the same species or genus ; and that this power of forming abstract ideas, is that which chiefly dis- tinguishes us from brute animals, in whom he eould see no evidence of any abstract ideas. Since the time of Des Cartes, philoso- phers have differed much with regard to the share they ascribe to the mind itself, in the fabrication of those representative beings called ideas, and the manner m which this work is carried on. * Locke has no originality in this respect. — H. \ Notion is here used for the apprehension of the idea, or representative reality, which Reid supposed that all philosophers viewed as something more than the mere act of knowledge, considered in relation to what was, through it, known or represented. — H, Of the authors I have met with, Dr Robert Hook is the most explicit. He was one of the most ingenious and active mem- bers of the Royal Society of London at its first institution ; and frequently read lec- tures to the Society, which were published among his posthumous works. [147] In his " Lectures upon Light," § 7, he makes ideas to be material substances ; and thinks that the brain is furnished with a proper kind of matter for fabricating the ideas of each sense. The ideas of sight, he thinks, are formed of a kind of matter resembling the Bononian stone, or some kind of phos- phorus ; that the ideas of sound are formed of some matter resembling the chords or glasses which take a sound from the vibra- tions of the air ; and so of the rest. . The soul, he thinks, may fabricate some hundreds of those ideas in a day ; and that, as they are formed, they are pushed farther off from the centre of the brain where the soul resides. By this means they make a con- tinued chain of ideas, coyled up in the brain ; the first end of which is farthest removed from the centre or seat of the soul, and the other end is always at the centre, being the last idea formed, which is always present the moment when considered ; and, there- fore, according as there is a greater number of ideas between the present sensation or thought in the centre and any other, the soul is apprehensive of a larger portion of time interposed. Mr Locke has not entered into so minute a detail of this manufacture of ideas ; but he ascribes to the mind a very considerable hand in forming its own ideas. With re- gard to our sensations, the mind is passive, " they being produced in us, only by dif- ferent degrees and modes of motion in our animal spirits, variously agitated by ex- ternal objects." These, however, cease to be as soon as they cease to be perceived ; but, by the faculties of memory and imagin- ation, " the mind has an ability, when it wills, to revive them again, and, as it were, to paint them anew upon itself, though some with more, some with less difficulty." As to the ideas of reflection, he ascribes them to no other cause but to that attention which the mind is capable of giving to its own operations. These, therefore, are formedbythe mind itself. [148] Heascribes likewise to the mind the power of com- pounding its simple ideas into complex ones of various forms ; of repeating them, and adding the repetitions together ; of dividing and classing them ; of comparing them, and, from that comparison, of forming the ideas of their relation j nay, of forming a general idea of a species or genus, by taking from the idea of an individual everything by which it is distinguished from other in. dividuals of the kind, till at last it becomes [146-148] □HAP. IX.j OF THE SENTIMENTS OF MR LOCKE. 277 an abstract general idea, common to all the individuals of the kind. These, I think, are the powers which Mr Locke ascribes to the mind itself in the fabrication of its ideas. Bishop Berkeley, as we shall see afterwards, abridged them considerably, and Mr Hume much more. The ideas we have of the various quali- ties of bodies are not all, as Mr Locke thinks, of the same kind. Some of them are images or resemblances of what is really in the body; others are not. There are certain qualities inseparable from matter; iuch as extension, solidity, figure, mobility. Our ideas of these are real resemblances of the qualities in the body ; and these he calls primary qualities. But colour, sound, taste, smell, heat, and cold, he calls second- ary qualities, and thinks that they are only powers in bodies of producing cer- tain sensations in us ; which sensations have nothing resembling them, though they are commonly thought to be exact resem- blances of something in the body. " Thus," says he, " the idea of heat or light, which we receive, by our eye or touch, from the sun, are commonly thought real qualities existing in the sun, and something more than mere powers in it." The names of primary and secondary qualities were, I believe, first used by Mr Locke ; but the distinction which they ex- press, was well understood by Des Cartes, and is explained by him in his " Principia," Part I., § 69, 70, 71. [149] ' Although no author has more merit than Mr Locke, in pointing out the ambiguity of words, and resolving, by that means, many knotty questions, which had tortured the wits of the schoolmen, yet, I apprehend, he has been sometimes misled by the ambi- guity of the word idea, which he uses so often almost in every page of his essay. In the explication given of this word, we took notice of two meanings given to it — a popular and a philosophical. In the popu- lar meaning, to have an idea of anything, signifies nothing more than to think of it. Although the operations of the mind are most properly and naturally, and indeed most commonly in all vulgar languages, ex- pressed by active verbs, there is another way of expressing them, less common, but equally well understood. To think of a thing, and to have a thought of it ; to be- lieve a thing, and to have a belief of it ; to see a thing, and have a sight of it ; to con- ceive a thing, and to have a conception, notion, or idea of it — are phrases perfectly synonymous. In these phrases, the thought means nothing but the act of thinking ; the belief, the act of believing ; and the con- ception, notion, or idea, the act* of conceiv- ing. To have a clear and distinct idea is, in this sense, nothing else but to conceive r U9, 1501 the thing clearly and distinctly. When the word idea is taken in this popular sense, there can be no doubt of our having ideas in our minds. To think without ideas would be to think without thought, which is a manifest contradiction.* But there is another meaning of the word idea peculiar to philosophers, and grounded upon a philosophical theory, which the vul- gar never think of. Philosophers, ancient and modern, have maintained that the operations of the mind, like the tools of an artificer, can only be employed upon objects that are present in the mind, or in the brain, where the mind is supposed to reside. [150] Therefore, obj ects that are distant in time or place must have a representative in the mind, or in the brain — some image or picture of them, which is the object that the mind contemplates. This representative image was, in the old philosophy, called a species or phantasm. Since the time of Des Cartes, it has more commonly been called an idea ; and every thought is con- ceived to have an idea of its object. As this has been a common opinion among philosophers, as far back as we can trace phi- losophy, it is the less to be wondered at that they should be apt to confound the opera- tion of the mind in thinking with the idea or object of thought, which is supposed to be its inseparable concomitant.* If we pay any regard to the common sense of mankind, thought and the object of thought are different things, and ought to be distinguished. It is true, thought cannot be without an object — for every man who thinks must think of something ; but the object he thinks of is one thing, his thought of that object is another thing. They are distinguished in all languages, even by the vulgar ; and many things may be affirmed of thought — that is, of the opera- tion of the mind in thinking — which cannot, without error, and even absurdity, be af- firmed of the object of that operation.* From this, I think, it is evident that, if the word idea, in a work where it occurs in every paragraph, is used without any inti- mation of the ambiguity of the word, some- times to signify thought, or the .operation of the mind in thinking, sometimes to sig- nify those internal objects of thought which philosophers suppose, this must occasion confusion in the thoughts both of the au- thor and of the readers. I take this to be the greatest blemish in the " Essay on Hu- man Understanding." I apprehend this is the true source of several paradoxical opin- ions in that excellent work, which I shall have occasion to take notice of. Here it is very natural to ask, Whether it was Mr Locke's opinion, that ideas are * See Note C H. 278 ON THE INTELLECTUAL POWERS. [essay u, the only objects of thought ? or, Whether it is not possible for men to think of things which are not ideas in the mind ?* [151] To this question it is not easy to give a direct answer. On the one hand, he says often, in distinct and studied expressions, that the term idea stands for whatever is the object of the understanding when a man thinks, or whatever it is which the mind can be employed about in thinking : that the mind perceives nothing but its own ideas : that all knowledge consists in the perception of the agreement or disagree- ment of our ideas : that we can have no knowledge farther than we have ideas. These, and many other expressions of the like import, evidently imply that every object of thought must be an idea, and can be nothing else. On the other hand, I am persuaded that Mr Locke would have acknowledged that we may think of Alexander the Great, or of the planet Jupiter, and of numberless things which he would have owned are not ideas in the mind, but objects which exist independent of the mind that thinks of them.-)- How shall we reconcile the two parts of this apparent contradiction ? All I am able to say, upon Mr Locke's principles, to recon- cile them, is this, That we cannot think of Alexander, or of the planet Jupiter, unless we have in our minds an idea — that is, an image or picture of those objects. The idea of Alexander is an image, or picture, or representation of that hero in my mind ; * It ia to be remembered that Keid means, by Ideas, representative entities different from the cog- nitive modifications of the mind itself. — H. t On the confusion of this and the four subsequent paragraphs, see Note C. — Whatever is the immediate object of thought, of that we are necessarily conscious. But of Alexander, for example, as existing, we are necessatily not conscious. Alexander, as existing, cannot, therefore, possibly be an immediate object of thought; consequently, if we can be said to think of Alexander at all, we can only be said to think of him mediately, in and through a representation of which we are conscious ; and that representation is the im. mediate object of thought. It makes no difference whether this immediate object be viewed as a tertium quid, distinct from the existing reality and from the conscious mind ; or whether as a mere modality of the conscious mind itself— as the mere act of thought considered in its relation to something beyond the sphere of consciousness. In neither case, can we be said (be it in the imagination of a possible or the recollection of a past existence) to know a thing as existing— that is, immediately ; and, therefore, if in these operations we be said to know aught out the mind at all, we can only be said to know it me- diately—in other words, as a mediate object. The whole perplexity arises from the ambiguity of the term object, that term being used both iortheexter. nal reality of which we are here not conscious, and cannot therefore know in itself, and for the mental representation which we know in itself, but which is known only as relativeto the other. Reid chooses to abolish the former signification, on the supposition that it only applies to a representative entity differ- ent from the act of thought. In this supposition, however, he is wrong ; nor does he obtain an imme- diate knowledge, even In perception, by merely deny. Ihecrude hypothesis of representation — H. and this idea is the immediate object of my thought when I think of Alexander. That this was Locke's opinion, and that it has been generally the opinion of philosophers, there can be no doubt. But, instead of giving light to the ques- tion proposed, it seems to involve it in greater darkness. When I think of Alexander, I am told there is an image or idea of Alexander in my mind, which is the immediate object of this thought. The necessary consequence of this seems to be, that there are two ob- jects of this thought — the idea, which is in the mind, and the person represented by that idea ; the first, the immediate object of the thought, the last, the object of the same thought, but not the immediate object. [152] This is a hard saying ; for it makes every thought of things external to have a double object. Every man is conscious of his thoughts, and yet, upon attentive reflec- tion, he perceives no such duplicity in the object he thinks about. Sometimes men see objects double, but they always know when they do so : and I know of no philo- sopher who has expressly owned this dupli- city in the object of thought, though it fol- lows necessarily from maintaining that, in the same thought, there is one object that is immediate and in the mind itself, and another object which is not immediate, and which is not in the mind.* Besides this, it seems very hard, or rather impossible, to understand what is meant by an object of thought that is not an imme- diate object of thought. A body in motion may move another that was at rest, by the medium of a third body that is interposed. This is easily understood ; but we are unable to conceive any medium interposed between a mind and the thought of that mind ; and, to think of any object by a medium, seems to be words without any meaning. There is a sense in which a thing may be said to be perceived by a medium. Thus any kind of sign may he said to be the medium by which I perceive or understand the thing signified. The sign by custom, or compact, or perhaps by nature, introduces the thought of the thing signified. But here the thing signified, when it is introduced to the thought, is an object of thought no less immediate than the sign was before. And there are here two objects of thought, one succeeding another, which we have shewn is not the case with respect to an idea, and the object it represents. • That is, if by object was meant the same thing, when the term is applied to the external reality, and to its mental representation. Even under the Scholastic theory of repeesentation, it was generally maintained that the species itself is not an object of perception, but the external reality through it ; a mode of speaking justly reprehended by the acuter schoolmen. But in this respect Reid is equally to blame. See Note C H. chap. ix.j OF THE SENTIMENTS OP MR LOCKE. 279 I apprehend, therefore, that, if philoso- phers will maintain that ideas in the mind are the only immediate objects of thought, they will he forced to grant that they are the sole objects of thought, and that it is im- possible for men to think of anything else. [ 1 53] Yet, surely, Mr Locke Believed that we can think of many things that are not ideas in the mind ; but he seems not to have perceived, that the maintaining that ideas in the mind are the only immediate objects of thought, must necessarily draw this con- sequence along with it. The consequence, however, was seen by Bishop Berkeley and Mr Hume, who rather chose to admit the consequence than to give up the principle from which it follows. Perhaps it was unfortunate for Mr Locke that he used the word idea so very fre- quently as to make it very difficult to give the attention necessary to put it always to the same meaning. And it appears evident that, in many places, he means nothing more by it but the notion or conception we have of any object of thought ; that is, the act of the mind in conceiving it, and not the object conceived.* In explaining this word, he says that he uses it for whatever is meant by phantasm, notion, species. Here are three synonymes to the word idea. The first and last are very proper to express the philosophical meaning of the word, being terms of art in the Peripatetic philosophy, and signifying images of external things in the mind, which, according to that philosophy, are objects of thought. But the word notion is a word in common language, whose meaning agrees exactly with the popular meaning of * When we contemplate a triangle, we may consider it either as a complement of three sides or of three angles ; not that the three sides and the three angles are possible except through each other, but because we may in thought view the figure— qua triangle, in reality one and indivisible— in different relations. In like manner, we may consider a representative act of knowledge in two relations— 1°, as an act represen- tative of something, and, 2° as an act cognitive of that representation, although, in truth, these are both only one indivisible energy — the representation only existing as known, the cognition being only possible in a representation. Thus, e. g„ in the imagination of a Centaur— the Centaur represented is the Centaur known, the Centaur known is the Centaur repre- sented. It is one act under two relations— a relation to the subject knowing — a relation to the object re- presented. But to a cognitive act considered in these several relations we may give either different names, or we may confound them under one, or we may do both ; and this is actually done ; some words express- ing only one relation, others both or either, and others properly the one but abusively also the other. Thus Idea properly denotes an act of thought con- sidered in relation to an external something beyond the sphere of consciousness — a representation; but some philosophers, as Locke, abuse it to comprehend the thought also, viewed as cognitive of this represen- tation. Again, perception, notion, conception, &c. (concept is, unfortunately, obsolete) comprehend both, or may be used to denote either of the rela- tions; and it is only by the context that we can ever vaguely discover in which application they are in- tended. This is unfortunate; but so it is. — H. [153-155] the word idea, but not with the philosophi. cal. When these two different meanings o< the word idea are confounded in a studied explication of it, there is little reason to expect that they should be carefully dis- tinguished in the frequent use of it. There are many passages in the Essay in which, to make them intelligible, the word idea must be taken in one of those senses, and many others in which it must be taken in the other. It seems probable that the author, not attending to this ambiguity of the word, used it in the one sense or the other, as the subject-matter required ; and the far greater part of his readers have done the same. [154] There is a third sense, in which he uses the word not unfrequently, to signify objects of thought that are not in the mind, but external. Of this he seems to be sensible, and somewhere makes an apology for it. When he affirms, as he does in innumerable places, that all human knowledge consists in the perception of the agreement or dis- agreement of our ideas, it is impossible to put a meaning upon this, consistent with his principles, unless he means by ideas every object of human thought, whether mediate or immediate ; everything, in a word, that can be signified by the subject, or predicate of a proposition. Thus, we see that the word idea has three different meanings in the essay; and the author seems to haveuseditsometimes in one, sometimes in another, without being aware of any change in the meaning. The reader slides easily into the same fallacy, that meaning occurring most readily to his mind which gives the best sense to what he reads. I have met with persons professing no slight acquaintance with the " Essay on Human Understanding," who maintained that the word idea, wherever it occurs, means nothing more than thought ; and that, where he speaks of ideas as images in the mind, and as objects of thought, he is not to be understood as speaking properly, but figuratively or analogically. And, indeed, I apprehend that it would be no small advantage to many passages in the book, if they could admit of -this interpretation. It is not the fault of this philosopher alone to have given too little attention to the distinction between the operations of the mind and the objects of those opera- tions. Although this distinction be familiar to the vulgar, and found in the structure of all languages, philosophers, when they speak of ideas, often confound [155] the two to- gether ; and their theory concerning ideas has led them to do so ; for ideas, being supposed to be a shadowy kind of beings, intermediate between the thought and the object of thought, sometimes seem to coa- 280 ON THE INTELLECTUAL, POWERS. Lessay II Iesce with the thought, sometimes with the object of thought, and sometimes to have a distinct existence of their own. The same philosophical theory of ideas has led philosophers to confound the differ- ent operations of the understanding, and to call them all by the name of perception.* Mr Locke, though not free from this fault, is not so often chargeable with it as some who came after him. The vulgar give the name of perception to that immediate know- ledge of external objects which we have by our external senses. + This is its proper meaning in our language, though sometimes it may be applied to other things metaphori- cally or analogically.^ When I think of anything that does not exist, as of the republic of Oceana, I do not perceive it — I only conceive or imagine it.§ When I think of what happened to me yesterday, I do not perceive but remember it.|| When I am pained with the gout, it is not proper to say I perceive the pain ; I feel it, or am conscious of it : it is not an object of per- ception, but of sensation and of conscious- ness.^ Sn far, the vulgar distinguish very properly the different operations of the mind, and never confound the names of things so different in their nature. But the theory of ideas leads philosophers to conceive all those operations to be of one nature, and to give them one name. ,T ne y are all, according to that theory, the per- ception of ideas in the mind. Perceiving, remembering, imagining, being conscious, are all perceiving ideas in the mind, and are called perceptions. Hence it is that philosophers speak of the perceptions of memory, and the perceptions of imagina- • No more than by calling them all by the name of Cognitions, or Acts of Consciouness. There was no reason, either from etymology or usage, why.per- ception should not signify the energy of immediately apprehending, in general ; and until Reid limited the word to our apprehension of an external world, it was, in fact, employed by philosophers, as tanta- mount to an act of consciousness. \Ve were in need of a word to express our sensitive cognitions as dis- tinct from our sensitive feelings, (for the term sens, ation involved both,) and, therefore, Reid's restric- tion, though contrary to all precedent, may be ad- mitted; but his criticism of ether philosophers for ;heir employment of the term, in a wider meaning, is wholly groundless. — H. t But not exclusively.— H. X This is not correct — H. \ And why ? Simply because we do not, by such an act, know, or apprehend such an object to exist ; we merely represent it. But perception was only used tor such an apprehension. We could say, how- ever, that we perceived (as we could say that we were conscious of) the republic of Oceana, as imagined by us, after Harrington. — H. || And this, for the same reason. What is remem- bered is not and can not be immediately known ; nought but the present mental representation is so known ; and this we could properly say that we perceived. — H. H Because the feeling of pain, though only possible through consciousness, is not an act of knowledge. But it could be properly said, 1 perceive a feeling of pain. A t any rate, the expression i perceive a pain, is as correct as I am conscious of a tarn. — H. tion. They make sensation to be a percep- tion; and everything we perceive by our senses to be an idea of sensation. Some- times they say that they are conscious of the ideas in their own minds, sometimes that they perceive them.* [156] However improbable it may appear that philosophers who have taken pains to study the operations of their own minds, should express them less properly and less dis- tinctly than the vulgar, it seems really to be the case ; and the only account that can be given of this strange phenomenon, I take to be this : that the vulgar seek no theory to account for the operations of their minds ; they know that they see, and hear, and re- member, and imagine ; and those who think distinctly will express these operations dis- tinctly, as their consciousness represents them to the mind ; but philosophers think they ought to know not only that there are such operations, but how they are per- formed ; how they see, and hear, and re- member, and imagine; and, having invented a theory to explain these operations, by ideas or images in the mind, they suit their expressions to their theory ; and, as a false comment throws a cloud upon the text, so a false theory darkens the phsenomena which it attempts to explain. We shall examine this theory afterwards. Here I would only observe that, if it is not true, it may be expected that it should lead ingenious men who adopt it to confound the operations of the mind with their objects, and with one another, even where the com- mon language of the unlearned clearly dis- tinguishes them. One that trusts to a false guide is in greater danger of being led astray, than he who trusts his own eyes, though he should be but indifferently ac- quainted with the road. CHAPTER X. OF THE SENTIMENTS OP BISHOP BERKELEY. George Berkeley, afterwards Bishop of Cloyne, published his " New Theory of Vision," in 1709; his "Treatise concern- ing the Principles of Human Knowledge," in 1710 ; and his " Dialogues between Hylas and Philonous," in 1713 ; being then a Fel- low of Trinity College, Dublin. [157] Heis acknowledged universally to have great merit, as an excellent writer, and a very acute and clear reasoner on the most ab- stract subjects, not to speak of his virtues as a man, which were very conspicuous : yet the doctrine chiefly held forth in the treatises above mentioned, especially in the • The connection of the wider signification of the term perception, with the more complex theory of representation, has no foundation— H. p56, 1571 ohap. x.] OF THE SENTIMENTS OF BISHOP BERKELEY. 281 two last, has generally been thought so very absurd, that few can be brought to think that he either believed it himself, or that he seriously meant to persuade others of its truth. He maintains, and thinks he has demon- strated, by a variety of arguments, ground- ed on principles of philosophy universally received, that there is no such thing as matter in the universe ; that sun and moon, earth and sea, our own bodies, and those of our friends, are nothing but ideas in the minds of those who think of them, and that they have no existence when they are not the objects of thought ; that all that is in the universe may be reduced to two cate- gories — to wit, minds, and ideas in the mind. But, however absurd this doctrine might appear to the unlearned, who consider the existence of the objects of sense as the most evident of all truths, and what no man in his senses can doubt, the philosophers who had been accustomed to consider ideas as the immediate objects of all thought, had no title to view this doctrine of Berkeley in so unfavourable a light. They were taught by Des Cartes, and by all that came after him, that the existence of the objects of sense is not self-evident, but requires to be proved by arguments ; and, although Des Cartes, and many others, had laboured to find arguments for this purpose, there did not appear to be that force and clearness in them which might have been expected in a matter of such im- portance. Mr Norris had declared that, after all the arguments that had been offered, the existence of an external world is only probable, but by no means certain. [158] Malebranchethoughtit rested upon the authority of revelation, and that the argu- ments drawn from reason were not perfectly conclusive. Others thought that the argu- ment from revelation was a mere sophism, because revelation comes to us by our senses, and must rest upon their authority. Thus we see that the new philosophy had been making gradual approaches towards Berkeley's opinion ; and, whatever others might do, the philosophers had no title to look upon it as absurd, or unworthy of a fair examination. Several authors attempt- ed to answer his arguments, but with little success, and others acknowledged that they could neither answer them nor assent to them. It is probable the Bishop made but few converts to his doctrine ; but it is cer- tain he made some ; and that he himself continued, to the end of his life, firmly per- suaded, not only of its truth,* but of its • Berkeley's confidence in his idealism was, how- ever, nothing to Fichte's. This philosopher, in one of his controversial treatises, imprecates everlasting damnation on himself not only should he retract, but fl6S, 1591 great importance for the improvement oi human knowledge, and especially for the defence of religion. Dial. Pref. " If the principles which I here endeavour to pro- pagate, are admitted for true, the conse- quences which I think evidently flow from thence are, that atheism and scepticism will be utterly destroyed, many intricate points made plain, great difficulties solved, several useless parts of science retrenched, speculation referred to practice, and men reduced from paradoxes to common sense." In the " Theory of Vision," he goes no farther than to assert that the objects of sight are nothing but ideas in the mind, granting, or at least not denying, that there is a tangible world, which is really external, and which exists whether we perceive it or not. Whetherthereasonof this was, that his system had not, at that time, wholly opened to his own mind, or whether he thought it prudent to let it enter into the minds of his readers by degrees, I cannot say. I think he insinuates the last as the reason, in the " Principles of Human Knowledge." [109] The" Theory of Vision," however, taken by itself, and without relation to the main branch of his system, contains very important discoveries, and marks of great genius. He distinguishes more accurately than any that went before him, between the immediate objects of sight, and those of the other senses which are early associated with them. He shews that distance, of itself and imme- diately, is not seen ; but that we learn to judge of it by certain sensations and per- ceptions which are connected with it. This is a very important observation; and, I believe, was first made by this author.* It gives much new light to the operations of our senses, and serves to account for many phenomena in optics, of which the greatest adepts in that science had always either given a false account, or acknow- ledged that they could give none at all. We may observe, by the way, that the ingenious author seems not to have attended to a distinction by which his general asser- tion ought to have been limited. It is true that the distance of an object from the eye is not immediately seen ; but there is a certain kind of distance of one object from another which we see immediately. The author acknowledges that there is a visible exten- sion, and visible figures, which are proper objects of sight ; there must therefore be a visible distance. Astronomers call it an- gular distance ; and, although they measure should he even waver in regard to any one principle of .his doctrine; a doctrine, the speculative result of which left him, as he confesses, without even a cer. tainty of his own existence. (See above, p. 129, note *,) It is Varro who speaks of the credula philosophorum natio : but this is to be credulous even in incredulity.— H. * This last statement is inaccurate. — H, 282 ON THE INTELLECTUAL POWERS. £essay II. it by the angle, which is made by two lines drawn from the eye to the two distant ob- jects, yet it is immediately perceived by sight, even by those who never thought of that angle. He led the way in shewing how we learn to perceive the distance of an object from the eye, though this speculation was carried farther by others who came after him. He made the distinction between that extension and figure which we perceive by sight only, and that which we perceive by touch ; call- ing the first, visible, the last, tangible ex- tension and figure. He shewed, likewise, that tangible extension, and not visible, is the object of geometry, although mathema- ticians commonly use visible diagrams in their demonstrations.* [160] The notion of extension and figure which we get from sight only, and that which we get from touch, have been so constantly conjoined from our infancy in all the judg- ments we form of the objects of sense, that it required great abilities to distin- guish them accurately, and to assign to each sense what truly belongs to it ; " so difficult a thing it is," as Berkeley justly observes, " to dissolve an union so early begun, and confirmed by so long a habit." This point he has laboured, through the whole of the essay on vision, with that uncommon penetration and judgment which he possessed, and with as great success as could be expected in a first attempt upon so abstruse a subject. He concludes this essay, by shewing, in no less than seven sections, the notions which an intelligent being, endowed with sight, without the sense of touch, might form of the objects of sense. This specu- lation, to shallow thinkers, may appear to be egregious trifling. ■)• To Bishop Ber- keley it appeared in another light, and will do so to those who are capable of entering into it, and who know the importance of it, iu solving many of the pheenomena of vision. He seems, indeed, to have exerted more force of genius in this than in the main branch of his system. In the new philosophy, the pillars by which the existence of a material world was supported, were so feeble that it did not require the force of a Samson to bring them * Properly speak ng, it is neither tangible nor visible extension which is the object of geometry, but intelligible, pure, or a priori extension. — H. t This, Ihave no doubt, is in allusion to Priestley. That writer had, not very courteously, said, in his ** Examination of Reid's Inquiry*" '' Ido not re. member to have seen a more egregious piece of so- lemn trifling than the chapter which our author calls the ' Geometry of Visibles,' and bis account of the ' Idomenians,' as he terms those imaginary beings who had no ideas of substance but fromsijht." — In a note upon that chapter of " The Inquiry," I stated that the thought of a Geometry of Visibles was original to Berkeley, and I had then no recollection of Reid's acknowledgment in the present paragraph. — H. down ; and in this we have not so much reason to admire the strength of Berkeley's genius, as his boldness in publishing to the world an opinion which the unlearned would be apt to interpret as the sign of a crazy intellect. A man who was firmly persuaded of the doctrine universally received by phi- losophers concerning ideas, if he could but take courage to call in question the exist- ence of a material world, would easily find unanswerable arguments in that doctrine. [161] " Some truths there are," says Berke. ley, " so near and obvious to the mind, that a man need only open his eyes to see them. Such," he adds, " I take this important one to be, that all the choir of heaven, and fur- niture of the earth— in a word, all those bodies which compose the mighty frame of the world — have not any subsistence without a mind." Princ. § 6. The principle from which this important conclusion is obviously deduced, is laid down in the first sentence of his principles of knowledge, as evident ; and, indeed, it has always been acknowledged by philosophers. " It is evident," says he, " to any one who takes a survey of the objects of human knowledge, that they are either ideas ac- tually imprinted on the senses, or else such as are perceived, by attending to the pas- sions and operations of the mind ; or, lastly, ideas formed by help of memory and imagin- ation, either compounding, dividing, or barely representing those originally per- ceived in the foresaid ways." This is the foundation on which the whole system rests. If this be true, then, indeed, the existence of a material world must be a dream that has imposed upon all mankind from the beginning of the world. The foundation on which such a fabric rests ought to be very solid and well esta- blished ; yet Berkeley says nothing more for it than that it is evident. If he means that it is self-evident, this indeed might be a good reason for not offering any direct argu- ment in proof of it. But I apprehend this cannot justly be said. Self-evident propo- sitions are those which appear evident to every man of sound understanding who ap- prehends the meaning of them distinctly, and attends to them without prejudice. Can this be said of this proposition, That all the objects of our knowledge are ideas in our own minds ?* I believe that, to any man • To the Idealist, it is of perfect indifference whether this proposition, in Reid's sense of the expression Ideas, be admitted, or whether it be held that we are conscious of nothing but of the modifications of our own minds. For, on the supposition that we can know the non-ego only in and through the ego, it follows, (since we can know nothing immediately of which we are not conscious, and it being allowed that we are conscious only of mind,) that it 4a con. tradictory to suppose aught, as known, (i.e., any ob- ject of knowledge,) to be known otherwise than as a phenomenon ot mind H. [160, 161"! (Jhap. x.J OF THE SENTIMENTS OF BISHOP BERKELEY. 283 uninstructed in philosophy, this proposition will appear very improbable, if not absurd. [162] However scanty his knowledge may be, he considers the sun and moon, the earth and sea, as objects of it; and it will be difficult to persuade him that those objects of his knowledge are ideas in his own mind, and have no existence when he does not think of them. If I may presume to speak my own sentiments, I once believed this doc- trine of ideas so firmly as to embrace the whole of Berkeley's system in consequence of it; till, finding other consequences to follow from it, which gave me more unea- siness than the want of a material world, it came into my mind, more than forty years ago, to put the question, What evi- dence have I for this doctrine, that all the objects of my knowledge are ideas in my own mind ? From that time to the pre- sent I have been candidly and impartially, as I think, seeking for the evidence of this principle, but can find none, excepting the authority of philosophers. We shall have occasion to examine its evidence afterwards. I would at present only observe, that all the arguments brought by Berkeley against the existence of a ma- terial world are grounded upon it ; and that he has not attempted to give any evidence for it, but takes it for granted, as other philosophers had done before him. But, supposing this principle to be true, Berkeley's system is impregnable. No demonstration can be more evident than his reasoning from it Whatever is per- ceived is an idea, and an idea can only exist in a mind. It has no existence when it is not perceived ; nor can there be any- thing like an idea, but an idea. So sensible he was that it required no laborious reasoning to deduce Ins system from the principle laid down, that he was afraid of being thought needlessly prolix in handling the subject, and makes an apology for it. Princ. § 22. " To what purpose is it," says he, " to dilate upon that which may be demonstrated, with the utmost evi- dence, in a line or two, to any one who is capable of the least reflection?" [163] But, though his demonstration might have been comprehended in aline or two, he very pru- dently thought that an opinion which the world would be apt to look upon as a mon- ster of absurdity, would not be able to make its way at once, even by the force of a naked demonstration. He observes, justly, Dial. 2, " That, though a demonstration be never so well grounded and fairly proposed, yet if there is, withal, a strain of prejudice, or a wrong bias on the understanding, can it be expected to perceive clearly, and adhere firmly to the truth ? No ; there is need of time and pains ; the attention must be iwakened and detained, by a frequent re- petition of the same thing, placed often in the same, often in different lights." It was, therefore, necessary to dwell upon it, and turn it on all sides, till it became familiar ; to consider all its consequences, and to obviate every prejudice and pre- possession that might hinder its admittance. It was even a matter of some difficulty to fit it to common language, so far as to enable men to speak and reason about it intelligibly. Those who have entered se- riously into Berkeley's system, have found, after all the assistance which his writings give, that time and practice are necessary to acquire the habit of speaking and think- ing distinctly upon it. Berkeley foresaw the opposition that would be made to his system, from two different quarters : first, from the philos- ophers ; and, secondly, from the vulgar, who are led by the plain dictates of nature. The first he had the courage to oppose openly and avowedly ; the second, he dreaded much more, and, therefore, takes a great deal of pains, and, I think, uses some art, to court into his party. This is particularly observable in his " Dia- logues." He sets out with a declaration, Dial. 1, " That, of late, he had quitted several of the sublime notions he had got in the schools of the philosophers, for vul- gar opinions," and assures Hylas, his fel- low-dialogist, " That, since this revolt from metaphysical notions to the plain dictates of nature and common sense, he found his understanding strangely enlightened; so that he could now easily comprehend a great many things, which before were all mys- tery and riddle." [164] Pref. to Dial. " If his principles are admitted for true, men will be reduced from paradoxes to common sense." At the same time, he acknowledges, " That they carry with them a great opposi- tion to the prejudices of philosophers, which have so far prevailed against the common sense and natural notions of mankind." When Hylas objects to him, Dial. 3, " You can never persuade me, Philonous, that the denying of matter or corporeal substance is not repugnant to the universal sense of mankind" — he answers, " I wish both our opinions were fairly stated, and submitted to the judgment of men who had plain common sense, without the prejudices of a learned education. Let me be repre- sented as one who trusts his senses, who thinks he knows the things he sees and feels, and entertains no doubt of their ex- istence. — If by material substance is meant only sensible body, that which is seen and felt, (and the unphilosophical part of the world, I dare say, mean no more,) then I am more certain of matter's existence than you or any other philosopher pretend to be. If there be anything which makes the 284 ON THE INTELLECTUAL POWERS. [_Bss*y if. generality of mankind averse from the notions I espouse, it is a misapprehension that I deny the reality of sensible things : but, as it is you who are guilty of that, and not I, it follows, that, in truth, their aversion is against your notions, and not mine. I am content to appeal to the common sense of the world for the truth of my notion. I am of a vulgar cast, simple enough to believe my senses, and to leave things as I find them. I cannot, for my life, help thinking that snow is white and fire hot." When Hylas is at last entirely converted, he observes to Philonous, " After all, the controversy about matter, in the strict acceptation of it, lies altogether between you and the philosophers, whose principles, I acknowledge, are not near so natural, or so agreeable to the common sense of man- kind, and Holy Scripture, as yours." [165] Philonous observes, in the end, " That he does not pretend to be a setter up of new notions ; his endeavours tend only to unite, and to place in a clearer light, that truth which was before shared between the vul- gar and the philosophers ; the former being of opinion, that those things they im- mediately perceive are the real things ; and the latter, that the things immediately perceived, are ideas which exist only in the mind ; which two things put together do, in effect, constitute the substance of what he advances.'' And he concludes by ob- serving, "That those principles which at first view lead to scepticism, pursued to a certain point, bring men back to common sense." These passages shew sufficiently the author's concern to reconcile his system to the plain dictates of nature and common sense, while he expresses no concern to reconcile it to the received doctrines of philosophers. He is fond to take part with the vulgar against the philosophers, and to vindicate common sense against their inno- vations. What pity is it that he did not carry this suspicion of the doctrine of philo- sophers so far as to doubt of that philoso- phical tenet on which his whole system is built — to wit, that the things immediately perceived by the senses are ideas which exist only in the mind ! After all, it seems no easy matter to make the vulgar opinion and that of Berkeley to meet. And, to accomplish this, he seems to me to draw each out of its line towards the other, not without some straining. The vulgar opinion he reduces to this, that the very things which we perceive by our senses do really exist. This he grants ;* for these things, says he, are ideas in our minds, or complexions of ideas, to which * Thifl is one of the passages that may be brought to prove that Keid did allow to the ego an immediate bud real knowledge of the non-ego. — H. we give one name, and consider as ona thing ; these are the immediate objects of sense, and these do really exist. As to the notion that those things have an absolute external existence, independent of being perceived by any mind, he thinks [166] that this is no notion of the vulgar, but a refine- ment of philosophers ; and that the notion of material substance, as a substratum, or sup- port of that collection of sensible qualities to which we give the name of an apple or a melon, is likewise an invention of philoso- phers, and is not found with the vulgar till they are instructed by philosophers. The substance not being an object of sense, the vulgar never think of it; or, if they are taught the use of the word, they mean no more by it but that collection of sensible qualities which they, from finding them con- joined in nature, have been accustomed to call by one name, and to consider as one thing. Thus he draws the vulgar opinion near to his own ; and, that he may meet it half way, he acknowledges that material things have a real existence out of the mind of this or that person ; but the question, says he, between the materialist and me, is, Whether they have an absolute existence distinct from their being perceived by God, and exterior to all minds ? This, indeed, he says, some heathens and philosophers have affirmed ; but whoever entertains no- tions of the Deity, suitable to the Holy Scripture, will be of another opinion. But here an objection occurs, which it required all his ingenuity to answer. It is this : The ideas in my mind cannot be the same with the ideas of any other mind ; therefore, if the objects I perceive be only ideas, it is impossible that the objects I per- ceive can exist anywhere, when I do not perceive them ; and it is impossible that two or more minds can perceive the same object. To this Berkeley answers, that this ob- jection presses no less the opinion of the materialist philosopher than his. But the difficulty is to make his opinion coincide with the notions of the vulgar, who are firmly persuaded that the very identical objects which they perceive, continue to exist when they do not perceive them ; and who are no less firmly persuaded that, when ten men look at the sun or the moon, they all see the same individual object.* [167] To reconcile this repugnancy, he observes, Dial. 3 — " That, if the term same be taken in the vulgar acceptation, it is certain (and not at all repugnant to the principles he maintains) that different persons may per- ceive the same thing ; or the same thing or idea exist in different minds. Words are • See the last note.— H. L165-1671 oifap. x.] OF THE SENTIMENTS OF BISHOP BERKELEY. 285 of arbitrary imposition ; and, since men are used to apply the word same, where no dis- tinction or variety is perceived, and he does not pretend to alter their perceptions, it follows that, as men have said before, several saw the same thing, so they may, upon like occasions, still continue to use the same phrase, without any deviation, either from propriety of language, or the truth of things ; but, if the term same be used in the acceptation of philosophers, who pretend to an abstracted notion of identity, then, according to their sundry definitions of this term, (for it is not yet agreed wherein that philosophic identity consists,) it may or may not be possible for divers persons to perceive the same thing ; but whether phi- losophers shall think fit to call a thing the same or no is, I conceive, of small import- ance. Men i"ay dispute about identity and divers"*' •■ iti-nut any real difference in their ll.ou lilt> and opinions, abstracted from names." Upon the whole, I apprehend that Berk- eley has carried this attempt to reconcile his system to the vulgar opinion farther than reason supports him ; and he was no doubt tempted to do so, from a just appre- hension that, in a controversy of this kind, the common sense of mankind is the most formidable antagonist. Berkeley has employed much pains and ingenuity to shew that his system, if re- ceived and believed, would not be attended with those bad consequences in the conduct of life, which superficial thinkers may be apt to impute to it. His system does not take away or make any alteration upon our plea- sures or our pains : our sensations, whether agreeable or disagreable, are the;same upon his system as upon any other. These are real things, and the only things that interest us. [168] They are produced in us according to certain laws of nature, by which our con- duct will be directed in attaining the one, and avoiding the other ; and it is of no moment to us, whether they are produced immediately by the operation of some power- ful intelligent being upon our minds: or by the mediation of some inanimate being which we call matter. The evidence of an all-governing mind, so far from being weakened, seems to appear even in a more striking light upon his hypothesis, than upon the common one. The powers which inanimate matter is. sup- posed to 'possess, have always been the stronghold of atheists, to which they had recourse in defence of their system. This fortress of atheism must be most effectually overturned, if there is no such thing as matter in the universe. In all this the Bishop reasons justly and acutely. But there is one uncomfortable consequence of his system, which he seems not to have at- fl68, 169] tended to, and from which it will be found difficult, if at all possible, to guard it. The consequence I mean is this — that, although it leaves us sufficient evidence of a supreme intelligent mind, it seems to take away all the evidence we have of other intelligent beings like ourselves. What I call a father, a brother, or a friend, is only a parcel of ideas in my own mind ; and, being ideas in my mind, they cannot possibly have that relation to another mind which they have to mine, any more than the pain felt by me can be the individual pain felt by another. I can find no principle in Berkeley's system, which affords me even probable ground to conclude that there are other intelligent beings, like myself, in the relations of father, brother, friend, or fellow-citizen. I am left alone, as the only creature of God in the universe, in that forlorn state of egoism into which it is said some of the disciples of Des Cartes were brought by his philo- sophy.* [169] Of all the opinions that have ever been advanced by philosophers, this of Bishop Berkeley, that there is no material world, seems the strangest, and the most apt to bring philosophy into ridicule with plain men whoare guided by the dictates of nature and common sense. And, it will not, I ap- prehend, be improper to trace this progeny of the doctrine of ideas from its origin, and to observe its gradual progress, till it acquired such strength that a pious and learned bishop had the boldness to usher it into the world, as demonstrable from the principles of philosophy universally received, and as an admirable expedient for the advance- ment of knowledge and for the defence of religion. During the reign of the Peripatetic phi- losophy, men were little disposed to doubt, and much to dogmatize. The existence of the objects of sense was held as a first prin- ciple ; and the received doctrine was, that the sensible species or idea is the very form of the external object, just separated from the matter of it, and sent into the mind that perceives it ; so that we find no appearance of scepticism about the existence of mat- ter under that philosophy. -(• Des Cartes taught men to doubt even of those things that had been taken for first principles. He rejected J the doctrine of • In which the soul, like the unhappy Dido— ^_— << semperque relinqui Solasibi, semper longam incomitatavidetur Ire viam." — H. f This is not the case. It could easily be shewn that, in the schools of the middle ages, the argument! in favour of Idealism were fully understood ; and they would certainly have obtained numerous parti. sans, had it not teen seen that such a philosophical opinion involved a theological heresy touching the eucharist. This was even recognised by St Augus- tine.— H. 1 After many of the Peripatetics themselves — H. 286 ON THE INTELLECTUAL POWERS. [ESSAY II. species or ideas coming from objects ; but still maintained that what we immediately perceive, is not the external object, but an idea or image of it in our mind. This led some of his disciples into Egoism, and to dis- believe the existence of every creature in the universe but themselves and their own ideas. • But Des Cartes himself — either from dread of the censure of the church, which he took great care not to provoke; orto shun the ridicule of the world, which might have crushed his system at once, as it did that of the Egoists ;* or, perhaps, from inward conviction — was resolved to support the ex- istence of matter. To do this consistently with his principles, he found himself obliged to have recourse to arguments that are far- fetched, and not very cogent. Sometimes he argues that our senses are given us by God, who is no deceiver ; and, therefore, we ought to believe their testimony. [170] But this argumentis weak ; because, accord- ing to his principles, our senses testify no more but that we have certain ideas : and, if we draw conclusions from this testimony, which the premises will not support, we deceive ourselves. To give more force to this weak argument, he sometimes adds, that we have by nature a strong propensity to believe that there is an external world corresponding to our ideas. + Malebranche thought that this strong propensity is not a sufficient reason for be- lieving the existence of matter ; and that it is to be received as an article of faith, not certainly discoverable by reason. He is aware that faith comes by hearing ; and that it may be said that prophets, apostles, and miracles are only ideas in our minds. But to this he answers, that, though these things are only ideas, yet faith turns them into realities ; and this answer, he hopes, will satisfy those who are not too morose. It may perhaps seem strange that Locke, who wrote so much about ideas, should not see those consequences which Berkeley thought so obviously deducible from that doctrine. Mr Locke surely was not willing that the doctrine of ideas should be thought to be loaded with such consequences. He acknowledges that the existence of a mate- rial world is not to be received as a first principle — nor is it demonstrable ; but he offers the best arguments for it he can ; and supplies the weakness of his arguments by this observation — that we have such evi- * See above, p. 26U, note & : and below, under p. I87.-H. t We are only by nature led to believe in the exist, ence of an outer world, because we are by nature led to believe that we have an immediate knowledge of it as existing. Now, Dee Cartes and the philosophers in general (is Reid an exception y) hold that we are deluded in the latter belief, and yet they argue, on the authority of the former, that an external world exists.— H. dence as is sufficient to direct us in pur. suing the good and avoiding the ill we may receive from external things, beyond which we have no concern. There is, indeed, a single passage in Locke's essay, which may lead one to con- jecture that he had a glimpse of that sys- tem which Berkeley afterwards advanced, but thought proper to suppress it within his own breast. [171] The passage is in Book 4, u. 10, where, having proved the existence of an eternal intelligent mind, he comes to answer those who conceive that matter also must be eternal, because we cannot conceive how it could be made out of nothing; and having observed that the creation of mind requires no less power than the creation of matter, he adds what fol- lows : — " Nay, possibly, if we could eman- cipate ourselves from vulgar notions, and raise our thoughts, as far as they would reach, to a closer contemplation of things, we might be able to aim at some dim and seeming conception, how matter might at first be made and begin to exist, by the power of that eternal first Being ; but to give beginning and being to a spirit, would be found a more inconceivable effect of om- nipotent power. But this being what would perhaps lead us too far from the notions on which the philosophy now in the world is built, it would not be pardonable to deviate so far from them, or to inquire, so far as grammar itself would authorize, if the com- mon settled opinion opposes it ; especially in this place, where the received doctrine serves well enough to our present purpose.* It appears from this passage — First, That Mr Locke had some system in his mind, perhaps not fully digested, to which we might be led, by raising our thoughts to a closer contemplation of things, and emanci- pating them from vulgar notions ; Secondly, That this system would lead so far from the notions on which the philosophy now in the world is built, that he thought proper to keep it within his own breast ; Thirdly, That it might be doubted whether this sys- tem differed so far from the common settled opinion in reality, as it seemed to do in words ; Fourthly, By this system, we might possibly be enabled to aim at some dim and seeming conception how matter might at first be made and begin to exist; but it would give no aid in conceiving how a spirit might be made. These are the cha- racteristics of that system which Mr Locke had in his mind, and thought it prudent to suppress. May they not lead to a probable conjecture, that it was the same, or some- thing similar to that of Bishop Berkeley ? * Mr Stewart plausibly supposes that this passage contains rather an anticipation of Boscovich's Theory of Matter, than of Berkeley's Theory of Idealism. Philosophical Essays, p. 61. But see note F.— H. [170, 171] chap. x.J OF THE SENTIMENTS OF BISHOP BERKELEY. 287 According to Berkeley's system, God'screat- ing the material world at such a time, means no more but that he decreed from that time, to produce ideas in the minds of finite spirits, in that order and according to those rules which we call the laws of Nature. [172] This, indeed, removes all difficulty, in con- ceiving how matter was created; and Berkeley does not fail to take notice of the advantage of his system on that account. But his system gives no aid in conceiving how a spirit may be made. It appears, therefore, that every particular Mr Locke has hinted, with regard to that system which he had in his mind, but thought it prudent to suppress, tallies exactly with the system of Berkeley. If we add to this, that Berkeley's system follows from Mr Locke's, by very obvious consequence, it seems rea- sonable to conjecture, from the passage now quoted, that he was not unaware of that consequence, but left it to those who should come after him to carry his principles their full length, when they should by time be better established, and able to bear the shock of their opposition to vulgar notions. Mr Norris, in his " Essay towards the Theory of the Ideal or Intelligible World," pub- lished in 1701, observes, that the material world is not an object of sense; because sensation is within us, and has no object. Its existence, therefore, he says, is a collec- tion of reason, and not a very evident one. From this detail we may learn that the doctrine of ideas, as it was new-modelled byjDes Cartes, looked with an unfriendly aspect upon the material world ; and, al- though philosophers were very unwilling to give up either, they found it a very difficult task to reconcile them to each other. In this state of things, Berkeley, I think, is reputed the first who had the daring reso- lution to give up the material world alto- gether, as a sacrifice to the received phi- losophy of ideas. But we ought not, in this historical sketch, to omit an author of far inferior name, Arthur Collier, Rector of Langford Magna, near Sarum. He published a book in 1713, which he calls " Clavis Universalis ; or, a New Inquiry after Truth ; being a demon- stration of the non-existence or impossibility of an external world." His arguments are the same in substance with Berkeley's; and he appears to understand the whole strength of his cause. [173] Though he is not deficient in metaphysical acuteness, his style is dis- agreeable, being full of conceits, of new- coined words, scholastic terms, and per- plexed sentences. He appears to be well acquainted with Des Cartes, Malebranche, and Norris, as well as with Aristotle and the schoolmen- But, what is very strange, it does not appear that he had ever heard of Locke's Essay, which had been pub- [172-174] lished twenty-four years, or of Berkeley's " Principles of Knowledge," which had been published three years. He says he had been ten years firmly convinced of the non-existence of an ex- ternal world, before he ventured to publish his book. He is far from thinking, as Ber- keley does, that the vulgar are of his opi- nion. If his book should make any con- verts to his system, (of which he expresses little hope, though he has supported it by nine demonstrations,) he takes pains to shew that his disciples, notwithstanding their opinion, may, with the unenlightened, speak of material things in the common style. He himself had scruples of con- science about this for some time ; and, if he had not got over them, he must have shut his lips for ever ; but he considered that God himself has used this style in speaking to men in the Holy Scripture, and has thereby sanctified it to all the faithful ; and that to the pure all things are pure. He thinks his opinion may be of great use, especially in religion ; and applies it, in particular, to put an end to the con- troversy about Christ's presence in the sacrament. I have taken the liberty to give this short account of Collier's book, because I believe it is rare, and little known. I have only seen one copy of it, which is in the University library of Glasgow. • [ 174] CHAPTER XI bishop Berkeley's sentiments of the nature of ideas. I pass over the sentiments of Bishop Berkeley, with respect to abstract ideas, and with respect to space and time, as things which may more properly be consi- dered in another place. But I must, take notice of one part of his system, wherein he • This work, though of extreme rarity, and long absolutely unknown to the philosophers of this coun- try, had excited, from the first, the attention of the German metaphysicians. A long analysis of it was given in the " Acta Eruditorum ; " it is found quoted by Bilfinger, and other Lebnitzians; and was sub. sequently translated into German, with controver- sial notes by Professor Eschenbach of Rostock, in his " Collection of the principal- writers who deny the Reality of their own Body and of the whole Corporeal World," 1756. The late learned Dr Parr had long the intention of publishing the work of Collier along with some other rare metaphysical treatises. He did not, however, accomplish his purpose; which in- volved, likewise, an introductory disquisition by him- self ; but a complete impression of the " Clavis Univer- salis" and four other tracts, was found, after his death ; and this having been purchased by-Mr Lum- ley, has, by him, been recently published, under the title — " Metaphysical Tracts, by English Philoso- phers of the Eighteenth Century," &c. London : 1837. A very small edition of the " Clavis" had been printed in Edinburgh, by private subscription, in tfw previous year. A Life of Collier has likewise re- cently appeared.— H. 288 ON THE INTELLECTUAL POWERS. [essay II seems to have deviated from the common opinion about ideas. Though he sets out in his principles of knowledge, by telling us that it is evident the objects of human knowledge are ideas, and builds his whole system upon this prin- ciple ; yet, in the progress of it, he finds that there are certain objects of human knowledge that are not ideas, but things which have a permanent existence. The objects of knowledge, of which we have no ideas, are our own minds, and their various operatious, other finite minds, and the Supreme Mind. The reason why there can be no ideas of spirits and their opera- tions, the author informs us is this, That ideas are passive, inert, unthinking beings ;* they cannot, therefore, be the image or likeness of things that have thought, and will, and active power ; we have notions of minds, and of their operations, but not ideas. We know what we mean by think- ing, willing, and perceiving ; we can rea- son about beings endowed with those powers, but we have no ideas of them. A spirit or mind is the only substance or support wherein the unthinking beings or ideas can exist ; but that this substance which supports or perceives ideas, should itself be an idea, or like an idea, is evidently absurd. He observes, farther, Princip. sect. 142, that " all relations, including an act of the mind, we cannot properly be said to have an idea, but rather a notion of the relations or habitudes between things. [175] But if, in the modern way, the word idea is extended to spirits, and relations, and acts, this is, after all, an affair of verbal con- cern ; yet it conduces to clearness and pro- priety, that we distinguish things very dif- ferent by different names." This is an important part of Berkeley's system, and deserves attention. We are led by it to divide the objects of human knowledge into two kinds. The first is ideas, which we have by our five senses ; they have no existence when they are not per- ceived, and exist only in the minds of those who perceive them. The second kind of objects comprehends spirits, their acts, and the relations and habitudes of things. Of these we have notions, but no ideas. No idea can represent them, or have any simi- litude to them : yet we understand what they mean, and we can speak with under- standing, and reason about them, without ideas. This account of ideas is very different from that which Locke has given. In his system, we have no knowledge where we have no ideas. Every thought must have • Berkeley is one of the philosophers who really held the doctrine of ideas, erroneously, by Reid, at- tributed to all.— H. an idea for its immediate object. In Ber- keley's, the most important objects are known without ideas. In Locke's system, there are two sources of our ideas, sensa- tion and reflection. In Berkeley's, sensa- tion is the only source, because of the objects of reflection there can be no ideas. We know them without ideas. Locke divides our ideas into those of substances, modes, and relations. In Berkeley's system, there are no ideas of substances, or of relations ; but notions only. And even in the class of modes, the operations of our own minds are things of which we have distinct notions ; but no ideas. We ought to do the j ustice to Malebranche to acknowledge that, in this point, as well as in many others, his system comes nearer to Berkeley's than the latter seems willing to own. That author tells us that there are four different ways in which we come to the knowledge of things. To know things by their ideas, is only one of the four. [ 176] He affirms that we have no idea of our own mind, or any of its modifications : that we know these things by consciousness, without ideas. Whether these two acute philosophers foresaw the consequences that may be drawn from the system of ideas, taken in its full extent, and which were after- wards drawn by Mr Hume, I cannot pre- tend to say. If they did, their regard to religion was too great to permit them to ad- mit those consequences, or the principles with which they were necessarily connected. However this may be, if there be so many things that may be apprehended and known without ideas, this very naturally suggests a scruple with regard to those that are left : for it may be said, If we can. apprehend and reason about the world of spirits, with- out ideas, Is it not possible that we may apprehend and reason about a material world, without ideas? If consciousness and reflection furnish us with notions of spirits and of their attributes, without ideas, may not our senses furnish us with notions of bodies and their attributes, without ideas ? Berkeley foresaw this objection to his system, and puts it in the mouth of Hylas, in the following words : — DiaL 3, Hylas. " If you can conceive the mind of God, without having an idea of it, why may not I be allowed to conceive the existence of matter, notwithstanding that I have no idea of it ?" The answer of Philonous is— " You neither perceive matter objectively, as you do an inactive being or idea, nor know it, as you do yourself, by a reflex act, neither do you immediately apprehend it by similitude of the one or the other, nor yet collect it by reasoning from that which you know immediately; all which makes the case of matter widely different from that of the Deity." ri75, 1761 chap, xi.] BISHOP BERKELEY'S SENTIMENTS OP IDEAS. 289 Though Hylas declares himself satisfied with this answer, I confess I am not : be- cause, if I may trust the faculties that God has given me, I do perceive matter objec- tively — that is, something which is extended and solid, which may be measured and weighed, is the immediate object of my touch andsight.* [177] And this object I take to be matter, and not an idea. And, though I have been taught by philosophers, that what I immediately touch is an idea, and not matter ; yet I have never been able to dis- cover this by the most accurate attention to my own perceptions. It were to be wished that this ingenious author had explained what he means by ideas, as distinguished from notions. The word notion, being a word in common lan- guage, is well understood. All men mean by it, the conception, the apprehension, or thought which we have of any object of thought. A notion, therefore, is an act of the mind conceiving or thinking of some object. The object of thought may be either something that is in the mind, or something that is not in the mind. It may be something that has no existence, or something that did, or does, or shall exist. But the notion which I have of that ob- ject, is an act of my mind which really exists while I think of the object ; but has no existence when I do not think of it. The word idea, in popular language, has precisely the same meaning as the word notion. But philosophers have another meaning to the word idea ; and what that meaning is, I think, is very difficult to say. The whole of Bishop Berkeley's system depends upon the distinction between no- tions and ideas ; and, therefore, it is worth while to find, if we are able, what those things are which he calls ideas, as distin- guished from notions. For this purpose, we may observe, that he takes notice of two kinds of ideas — the ideas of sense, and the ideas of imagina- tion. " The ideas imprinted on the senses by the Author of Nature," he says, " are called real things; and those excited in the imagination, being less regular, vivid, and constant, are more properly termed ideas, or images of things, which they copy and represent. [178] But then our sensations, be they never so vivid and distinct, are nevertheless ideas ; that is, they exist in the mind, or are perceived by it as truly as the ideas of its own framing. The ideas of sense are allowed to have more reality in them — that is, to be more strong, or- derly, and coherent — than the creatures of * Does Reid'mean to surrender his doctrine, that perception is a conception— that extension and figure are not known by sense, but are-notions suggested on the occasion of sensation ? If he does not, his lan- guage in the text is inaccurate.— H. | 177-179] the mind. They are also less dependent on the spirit, or thinking substance which perceives them, in that they are excited by the will of another and more powerful spirit ; yet still they are ideas ; and cer- tainly no idea, whether faint or strong, can exist, otherwise than in a mind perceiving it." Principles, § 33. From this passage we see that, by the ideas of sense, the author means sensa- tions ;* and this, indeed, is evident from many other passages, of which I shall men- tion a few. — Principles, § 5. " Light and colours, heat and cold, extensionandfigure— in a word, the things we see and feel — what are they but so many sensations, notions, ideas, or impressions on the sense ?— and is it possible to separate, even in thought, any of these from perception ? For my part, I might as easily divide a thing from itself." § 18. "As for our senses, by them we have the knowledge only of our sensations, ideas, or those things that are immediately perceived by sense, call them what you will ; — but they do not inform us that things exist without the mind, or un- perceived, like to those which are per- ceived." § 25. " All our ideas, sensa- tions, or the things which we perceive, by whatever names they may be distinguished, are visibly inactive; there is nothing of power or agency included in them." This, therefore, appears certain — that, by the ideas of sense, the author meant the sensations we have by means of our senses. I have endeavoured to explain the meaning of the word sensation, Essay I., chap. 1, [p. 229,] and refer to the explication there given of it, which appears to me to be per- fectly agreeable to the sense in which Bishop Berkeley uses it.* As there can be no notion or thought but in a thinking being ; so there can be no sensation but in a sentient being. [179] It is the act or feeling of a sentient being ; its very essence consists in its being felt. Nothing can resemble a sensation, but a similar sensation in the same or in some other mind. To think that any quality in a thing that is inanimate can resemble a sensation, is a great absurdity. In all this, I cannot but agree perfectly with Bishop Berkeley ; and I think his notions of sensa- * How it can beiasserted. that by ideas of sense Berkeley meant only what Reid did by sensations, I cannot comprehend. That the former used ideas of sense and sensations as convertible expressions, is true. But then Berkeley's sensation was equivalent to Reid's sensation plus his perception. This is mani- fest even by the passages adduced in the text. In that from § v. .of the " Principles," Berkeley ex. pressly calls extension and-Jigure sensations. But it is a fundamental' principle of Reid'? philosophy, not only that neither extension nor figure, but that none of the .primary qualities, are sensations. To make a single quotation— *"Thepriviarpqua\itieB" he says, *' are. neither sensations, nor are'they the resemblances of sensations."— Infra, p. 238.— H. 290 ON THE INTELLECTUAL POWERS. (jessay n. tion much more distinct and accurate than Locke's, who thought that the primary qualities of body are resemblances of our sensations,* but that the secondary are not. That we have many sensations by means of our external senses, there can be no doubt ; and, if he is pleased to call those ideas, there ought to be no dispute about the meaning of a word. But, says Bishop Berkeley, by our senses, we have the know- ledge, only of our sensations or ideas, call them which you will. I allow him to call them which he will ; but I would hare the word only in this sentence to be well weighed, because a great deal-depends upon it. For, if it be true that, by our senses, we have the knowledge of our sensations only, then his system must be admitted, and the existence of a material world must be given up as a dream. No demonstration can be more invincible than this. If we have any knowledge of a material world, it must be by the senses : but, by the senses, we have no knowledge but of our sensations only ; and our sensations have no resemblance of anything that can be in a material world. + The only proposition in this demonstration which admits of doubt is, that, by our senses, we have the knowledge of our sensations only, and of nothing else. If there are ob- jects of the senses which are not sensations, his arguments do not touch them : they may be things which do not exist in the mind, as all sensations do ; they may be things of which, by our senses, we have notions, though no ideas; just as, byconsciousness and reflection, we have notions of spirits and of their oper- ations, without ideas or sensations.} [180] Shall we say, then, that, by our senses, we have the knowledge of our sensations only ; and that they give us no notion of anything but of our sensations ? Perhaps this has been the doctrine of philosophers, and not of Bishop Berkeley alone, otherwise he would have supported it by arguments. Mr Locke calls all the notions we have by our senses, ideas of sensation ; and in tins has been very generally followed. Hence it seems a very natural inference, that ideas * Here again we have a criticism which proceeds on. the erroneous implication, that Locke meant by sensation what Heid himself did. If for sensation we substitute perception, (and by sensation Locke denoted both sensation proper and perception proper,) there remains nothing to censure ; for Reid main- tains that " our senses give us adirect andadistinct notion of the primary qualities, and inform us what thty are in themselves " (infra, p. 237 ;) which is only Locke's meaning in other words. The same observa- tion applies to many of the following passages. — H. t See the last note.— H. t But, unless that be admitted, which the natural conviction of mankind certifies, that we have an immediate perception— a consciousness — of external and extended existences, it makes no difference, in regard to the conclusion of the Idealist, whether ■fc'liat we are conscious of in perception be supposed an entity in the mind, (an idea in Reids meaning,) or a modification of the mind, (a notion- or concep. tion.) See above, p. 12S, notes *. — H. of sensation are sensations. But philoso- phers may err : let us hear the dictates of common sense upon this point- Suppose I am pricked with a pin, I ask, Is the pain I feel, a sensation ? Undoubtedly it is. There can be nothing that resembles pain in any inanimate being. But I ask again, Is the pin a sensation? To this question I find myself under a necessity of answering, that the pin is not a sensation, nor can have the least resemblance to any sensation. The pin has length and thick- ness, and figure and weight. A sensation can have none of those qualities. I am not more certain that the pain I feel is a sensa- tion, than that the pin is not a sensation ; yet the pin is an object of sense ; and I am as certain that I perceive its figure and hardness by my senses, as that I feel pain when pricked by it.* Having said so much of the ideas of sense in Berkeley's system, we are next to con- sider the account he gives of the ideas of imagination. Of these he says, Principles, § 28 — " I find I can excite ideas in my mind at pleasure, and vary and shift the scene as oft as I think fit. It is no more than willing ; and straightway this or that idea arises in my fancy ; and by the same power it is obliterated, and makes way for another. This making and unmaking of ideas, doth very properly denominate the mind active. Thus much is certain, and grounded on experience. Our sensations," he says, " are called real things ; the ideas of imagination are more properly termed ideas, or images of things ;"■(• that is, as I apprehend, they are the images of our sensations. [181] It might surely be expected that we should be well acquainted with the ideas of imagin- ation, as they are of our making ; yet, after all the Bishop has said about them, I am at a loss to know what they are. I would observe, in the first place, with regard to these ideas of imagination — that they are not sensations ; for surely sensation is the work of the senses, and not of imagin- ation ; and, though pain be a sensation, the thought of pain, when I am not pained, is no sensation. I observe, in the second place — that I can find no distinction between ideas of imagin- ation and notions, which the author says are not ideas. I can easily distinguish be- • This illustration is taken from Des Cartes. In this paragraph, the term sensation is again not used in tions are notions and not ideas, since they are made and unmade by the mind as it thinks fit .- and, from this, it is properly de- nominated active. % * That is, no images of them in the phantasy. Reid himself would not say that such could be imagined. — H. f Berkeley does not say so in the meaning -sup- posed. — H. (.Imagination is an ambiguous word; it. means either the act of imagining, or the product— i. e, the image imagined. Of the former, Berkeley held, we can form a notion, but not an -idea, in the sense ht U 2 292 ON THE INTELLECTUAL POWERS. f ESSAY II. When so much has been written, and so many disputes raised about ideas, it were desirable that we knew what they are, and to what category or class of beings they be- long. In this we might expect satisfaction in the writings of Bishop Berkeley, if any- where, considering his known accuracy and precision in the use of words ; and it is for this reason that I have taken so much pains to find out what he took them to be. After all, if I understand what he calls the ideas of sense, they are the sensations which we have by means of our five senses ; but they are, he says, less properly termed ideas. I understand, likewise, what he calls notions ; but they, says he, are very differ- ent from ideas, though, in the modern way, often called by that name. The ideas of imagination remain, which are most properly termed ideas, as he says ; and, with regard to these, I am still very much in the dark. When I imagine a lion or an elephant, the lion or elephant is the object imagined. The act of the mind, in conceiving that object, is the notion, the conception, or imagination of the object. If besides the object, and the act of the mind about it, there be something called the idea of the object, I know not what it is.* If we consult other authors who have treated of ideas, we shall find as little satis- faction with regard to the meaning of this philosophical term. [184] The vulgar have adopted it ; but they only mean by it the notion or conception we have of any object, especially our more abstract or gen- eral notions. When it is thus put to sig- nify the operation of the mind about objects, whether in conceiving, remembering, or perceiving, it is well understood. But phi- losophers will have ideas to be the objects of the mind's operations, and not the oper- ations themselves. There is, indeed, great variety of objects of thought. We can think of minds, and of their operations ; of bodies, and of their qualities and relations. If ideas are not comprehended under any of these classes, I am at a loss to comprehend what they are. In ancient philosophy, ideas were said to be immaterial forms, which, according to one system, existed from all eternity ; and, according to another, are sent forth from the objects whose form they are.-)- In mo- dern philosophy, they are things in the mind, which are the immediate objects of all our thoughts, and which have no exist- ence when we do not think of them. They are called the images, the resemblances, the uses the term ; whereas, of the latter, we can form an idea by merely repeating the imaginatory act — a. * On Keid's misconception on this point, see Note B.— H. t Nothing by the name of idea was sent off from objects in the ancient philosophy. — H. representatives of external objects of sense ; yet they have neither colour, nor smell, nor figure, nor motion, nor any sensible quality. I revere the authority of philosophers, espe. cially where they are so unanimous ; but until I can comprehend what they mean by ideas, I must think andspeak with the vulgar. In sensation, properly so called, I can distinguish two things— the mind, or sen- tient being, and the sensation. Whether the last is to be called a feeling or an oper- ation, I dispute not ; but it has no object distinct from the sensation itself. If in sensation there be a third thing, called an idea, I know not what it is. In perception, in remembrance, and in conception, or imagination, I distinguish three things — the mind that operates, the operation of the mind, and the object of that operation.* [185] That the object per- ceived is one thing, and the perception of that object another, I am as certain as I can be of anything. The same may be said of conception, of remembrance, of love and hatred, of desire and aversion. In all these, the act of the mind about its object is one thing, the object is another thing. There must be an object, real or imaginary, distinct from the operation of the mind about it.-)- Now, if in these operations the idea be a fourth thing different from the three I have mentioned, I know not what it is, nor have been able to learn from all that has been written about ideas. And if the doctrine of philosophers about ideas con- founds any two of these things which I have mentioned as distinct — if, for example, it confounds the object perceived with the perception of that object, and represents them as one and the same thing— such doc- trine is altogether repugnant to all that I am able to discover of the operations of my own mind ; and it is repugnant to the common sense of mankind, expressed in the struc- ture of all languages. CHAPTER XII. OP THE SENTIMENTS OP MR HUME. Two volumes of the "Treatise of Human Nature" were published in 1739, and the third in 1740. The doctrine contained in this Treatise was published anew in a more popular form in Mr Hume's "Philosophical Essays," of which there have been various editions. What other authors, from the • See Note B.— H. f If there bean imaginary object distinct from the act of imagination, where does it exist P It cannot be external to the mind — for, ex liypothesi, it is ima. ginary ; and, if in the mind itself, distinct from the act of imagination— why. what is this but the very crudest doctrine of specks f For Reid'8 puzzle, see Note B. — H, ["184, 185] chap.xii.J OF THE SENTIMENTS OF MR HUME. 293 time of Des Cartes, had called ideas, this author distinguishes into two kinds — to wit, impressions aud ideas ; comprehending under the first, all our sensations, passions, and emotions ; and under the last, the faint images of these, when we remember or imagine them. [186] He sets out with this, as a principle that needed no proof, and of which therefore he offers none— that all the perceptions of the human mind resolve themselves into these two kinds, impressions and ideas. As this proposition is tho foundation upon which the whole of Mr Hume's system rests, and from which it is raised with great acuteness indeed, and ingenuity, it were to be wished that he had told us upon what authority this fundamental proposition rests. But we are left to guess, whether it is held forth as a first principle, which has its evidence in itself ; or whether it is to be received upon the authority of philosophers. Mr Locke had taught us, that all the immediate objects of human knowledge are ideas in the mind. Bishop Berkeley, pro- ceeding upon this foundation, demonstrated, very easily, that there is no material world. And he thought that, for the purposes both of philosophy and religion, we should find no loss, but great benefit, in the want of it. But the Bishop, as became his order, was unwilling to give up the world of spirits. He saw very well, that ideas are as unfit to represent spirits as they are to represent bodies. Perhaps he saw that, if we per- ceive only the ideas of spirits, we shall find the same difficulty in inferring their real existence from the existence of their ideas, as we find in inferring the existence of matter from the idea of it ; and, therefore, while he gives up the material world in favour of the system of ideas, he gives up one-half of that system in favour of the world of spirits ; and maintains that we can, without ideas, think, and speak, and reason, intelligibly about spirits, and what belongs to them. Mr Hume shews no such partiality in favour of the world of spirits. He adopts the theory of ideas in its full extent ; and, in consequence, shews that there is neither matter nor mind in the universe ; nothing but impressions and ideas. "What we call a body, is only a bundle of sensations ; and what we call the mind is only a bundle of thoughts, passions, and emotions, without any subject. [187] Some ages hence, it will perhaps be looked upon as a curious anecdote, that two philosophers of the eighteenth century, of very distinguished rank, were led, by a philosophical hypothesis, one, to disbelieve the existence of matter, and the other, to disbelieve the existence both of matter and of mind. Such an anecdote may not be uninstructive, if it prove a, warning to [ 186-188] philosophers to beware of hypotheses, espe- cially when they lead to conclusions which contradict the principles upon which all men of common sense must act in common life. The Egoists," whom we mentioned be- fore, were left far behind by Mr Hume ; for they believed their own existence, and perhaps also the existence of a Deity. But Mr Hume's system does not even leave him a self to claim the property of his impres- sions and ideas. A system of consequences, however ab- surd, acutely and justly drawn from a few principles, in very abstract matters, is of real utility in science, and may be made subservient to real knowledge. This merit Mr Hume's metaphysical writings have in a great degree. We had occasion before to observe, that, since the time of Des Cartes, philosophers, in treating of the powers of the mind, have, in many instances, confounded things which the common sense of mankind has always led them to distinguish, and which have different names in all languages. Thus, in the perception of an external object, all languages distinguish three things— the mind that perceives, the operation of that mind, which is called perception, and the object perceived. + Nothing appears more evident to a mind untutored by philosophy, than that these three are distinct things, which, though related, ought never to be confounded. [188] The structure of all languages supposes this distinction, and is built upon it. Philosophers have intro- duced a fourth thing in this process, which they call the idea of the object, which is supposed to be an image, or representative of the object, and is said to be the imme- diate object. The vulgar know nothing about this idea ; it is a creature of philo- sophy ,introduced to account for and explain the manner of our perceiving external objects. * In supplement to note § at p. 269, supra, in re- gard to the pretended^sect of Egoists, there is to be added the following notices, which I did not recol- lect till after that note was set : — Wolf, (Psychologia Rationalis, § 38,) after dividing Idealists into Egoists and Pluralists, says,inter alia, of the former : — " Fuit paucis abhinc annis assecla Jjuidam Malebranchii, Parisiis, qui Egoismum pro- essus est (quod mirum mihi videtur) asseclas et ipse nactus est." In his Vernuenftigc Gedankmvon Gott, &c, c. I , \1, he also mentions this alterseltsamste Sects. There is also an oration by Christopher Matthaeus Pfaff, the Chancellor of Tuebingen— ** De Egoismo, nova philosophica haeresi," in 1723— which I have not seen. — '1 hus, what I formerly ha- zarded, is still farther confinntd. All is vague and contradictory hearsay in regard to the Egoists. The French place them in Scotland ; the Scotch in Hoi- land ; the Germans in France j and they are various! v stated as the immediate disciples of Des Cartes, Malebranche, Spinoza. There is certainly no reason why an Egoistical Idealism should not have been explicitly promulgated before Fichte, (whose doctrine, however, is not the same ;) but I have, as yet, seen no satisfactory grounds on which it can. be shewn that this had actually been done.— H. t See Notes B and C— H. 294 ON THE INTELLECTUAL POWERS. [essay II. It ia pleasant to observe that, while philo- sophers, for more than a century, have been labouring, by means of ideas, to explain perception and the other operations of the mind, those ideas have by degrees usurped the place of perception, object, and even of the mind itself, and have supplanted those very things they were brought to explain. Des Cartes reduced all the operations of the understanding to perception ; and what can be more natural to those who believe that they are only different modes of perceiving ideas in our own minds ? Locke confounds ideas sometimes with the perception of an external object, sometimes with the external object itself. In Berkeley's system, the idea is the only object, and yet is often con- founded with the perception of it. But, in Hume's, the idea or the impression, which is only a more lively idea, is mind, percep- tion, and object, all in one : so that, by the term perception, in Mr Hume's system, we must understand the mind itself, all its operations, both of understanding and will, and all the objects of these operations. Per- ception taken in this sense he divides into our more lively perceptions, which he calls impressions* and the less lively, which he calls ideas. To prevent repetition, I must here refer the reader to some remarks made upon this division, Essay I. chap. 1, in the explication there given of the words, per- ceive, object, impression, [pp. 222, 223, 226.] Philosophers have differed very much with regard to the origin of our ideas, or the sources whence they are derived. The Peripatetics held that all knowledge is de- rived originally from the senses ;■(■ and this ancient doctrine seems to be revived by some late French philosophers, and by Dr Hartley and Dr Priestley among the Brit- ish. [189] Des Cartes maintained, that many of our ideas are innate. Locke op- posed the doctrine of innate ideas with much zeal, and employs the whole first book of his Essay against it. But he ad- mits two different sources of ideas . the operations of our external senses, which he calls sensation, by which we get all our ideas of body, and its attributes ; and re- flection upon the operations of our minds, by which we get the ideas of everything be- • Mr Stewart (Etem. III. Addenda to vol L p. 43) seems to think that the word impression was first introduced as a technical .term, into the philo- sophy of mind, by Hume. This is not altogether correct. For, besides the instances which Mr Stewart himself adduces, of the illustration attempted, of the phenomena of memory from the analogy of an im- press and a ttace, words corresponding to impression were among the ancients familiarly applied to the pro- cesses of external perception, imagination, &c.,in the Atomistic, the Platonic, the Aristotelian, and the Stoical philosophies ; while, among modern psycholo- gists, (as Di s Cartes and Gassendi,; the term was like- wise in common use.— H. t This is an Incorrect, at least a too unqualified, statement. — H. longing to the mind. The main design of the second book of Locke's " Essay," is to shew, that all our simple ideas, without exception, are derived from the one or the other, or both of these sources. In doing this, the author b led into some paradoxes, although, in general, he is not fond of para- doxes : And had he foreseen all the con- sequences that may be drawn from his ac- count of the origin of our ideas, he would probably have examined it more carefully." Mr Hume adopts Locke's account of the origin of our ideas ; and from that principle infers, that we have no idea of substance, corporeal or spiritual, no idea of power, no other idea of a cause, but that it is something antecedent, and constantly conjoined to that which we call its effect ; and, in a word, that we can have no idea of anything but our sensations, and the operations of mind we are conscious of. This author leaves no power to the mind in framing its ideas and impressions ; and, no wonder, since he holds that we have no idea of power ; and the mind is nothing bnt that succession of impressions and ideas of which we are intimately conscious. He thinks, therefore, that our impressions arise from unknown causes, and that the impressions are the causes of their corre- sponding ideas. By this he means no mora but that they always go before the ideas ; for this is all that is necessary to constitute the relation of cause and effect. [190] As to the order and succession of our ideas, he holds it to be determined by three laws of attraction or association, which he takes to be original properties of the ideas, by which they attract, as it were, or asso- ciate themselves with other ideas which either resemble them, or which have been contiguous to them in time and place, or to which they have the relations of cause and effect. We may here observe, by the way, that the last of these three laws seems to be in- cluded in the second, since causation, ac- cording to him, implies no more than con. tiguity in time and place. -(■ » At any rate, according to Locke, all our know- ledge is a derivation from experience. — H. t Mr Hume says—" I do not find that any philo- sopher has attempted to enumerate or class all the principles of Association ; a subject, however, that seems to me very worthy of curiosity. To me there appears to be only three principles of connection among ideas : Resemblance — Contiguity in time or place— Cause and Effect,*' — Essays, vol. ii., p. 24— Aristotle, and, after him, many other philosophers, had, however, done this, and with even greater success than Hume himself. Aristotle's reduction is to the four following heads . — Proximity in time — Conti. guity in place — Resemblance — Contrast. This is more correct than Hume's ; for Hume's second head ought to be divided into two ; while our connecting any particular events in the relation of cause and effect, is itself the result of their observed proximity in time and contiguity in place ; nay, to custom and this empirical connection (as observed by Keid) does [189, 190'J chap. xuiJOF THE SENTIMENTS OF ANTHONY ARNAULD. 29.5 It is not my design at present to shew how Mr Hume, upon the principles he has borrowed from Locke and Berkeley, has, with great acuteness, reared a system of absolute scepticism, which leaves no rational ground to believe any one proposition, rather than its contrary : my intention in this place being only to give a detail of the sentiments of philosophers concerning ideas since they became an object of speculation, and concerning the manner of our perceiv- ing external objects by their means. CHAPTER XIII. OP THE SENTIMENTS OF ANTHONY ARNAULD. In this sketch of the opinions of philoso- phers concerning ideas, we must not omit Anthony Arnauld, doctor of the Sorbonne, who, in the year 1683, published his book " Of True and False Ideas," in opposition to the system of Malebranche before men- tioned. It is only about ten years since I could find this book, and I believe it is rare." [191] Though Arnauld wrote before Locke, Berkeley, and Hume, I have reserved to the last place some account of his senti- ments, because it seems difficult to deter- mine whether he adopted the common theory of ideas, or whether he is singular in reject- ing it altogether as a fiction of philoso- phers. * The controversy between Malebranche and Arnauld necessarily led them to con- sider what kind of things ideas are — a point upon which other philosophers had very generally been silent. Both of them pro- fessed the doctrine universally received: that we perceive not material things imme- diately — that it is their ideas that are the immediate objects of our thought — and that it is in the idea of everything that we per- ceive its properties. It is necessary to premise that both these authors use the word perception, as Des Cartes had done before them, to sig- nify every operation of the understand- ing.-f- " To think, to know, to perceive, are the same thing," says Mr Arnauld, chap, v. def. 2. It is likewise to be observed, that the various operations of the mind are by both called modifications of the mind. Perhaps they were led into this phrase by the Cartesian doctrine, that the essence of the mind consists in thinking, as that of body consists in extension. I apprehend, Hume himself endeavour to reduce the principle of Causality altogether.— H. See NotesD**andD**«. * The treatises of Arnauld in his controversy with Malebranche, are to be found in the ihirly.eiohth volume of his collected works in 4to. — H. t Every apprehensive, or strictly cognitive opera, tion of the understanding.— H. [191,1931 therefore, that, when they make sensation, perception, memory, and imagination, to be various modifications of the mind, they mean no more but that these are things which can only exist in the mind as their subject. We express the same thing, by calling them various modes of thinking, or various operations of the mind.* The things which the mind perceives, says Malebranche, are of two kinds. They are either in the mind itself, or they are external to it. The things in the mind, are all its different modifications, its sensa- tions, its imaginations, its pure intellec- tions, its passions and affections. These are immediately perceived ; we are con- scious of them, and have no need of ideas to represent them to us. [192] Things external to the mind, are either corporeal or spiritual. With regard to the last, he thinks it possible that, in another state, spirits may be an immediate object of our understandings, and so be perceived without ideas ; that there may be such an union of spirits as that they may imme- diately perceive each other, and communi- cate their thoughts mutually, without signs and without ideas. But, leaving this as a problematical point, he holds it to be undeniable, that material things cannot be perceived immediately, but only by the mediation of ideas. He thought it likewise undeniable, that the idea must be immediately present to the mind, that it must touch the soul as it were, and modify its perception of the object. From these principles we must neces- sarily conclude, either that the idea is some modification of the human mind, or that it must be an idea in the Divine Mind, which is always intimately present with our minds. The matter being brought to this alternative, Malebranche considers first all the possible ways such a modifica- tion may be produced in our mind as that we call an idea of a material object, taking it for granted always, that it must be an object perceived, and something different from the act of the mind in perceiving it. He finds insuperable objections against every hypothesis of such ideas being pro- duced in our minds; and therefore- con- cludes, that the immediate objects of per- ception are the ideas of the Divine Mind. Against this system Arnauld wrote his book " Of True and False Ideas." He does not object to the alternative men- tioned by Malebranche ; but he maintains, that ideas are modifications of our minds. And, finding no other modification of the * Modes, or modifications ofmind,m the Cartesian school, mean merely what some recent philosopher* express by states of mind and include .both the arrive and passive phenomena of the conscious suit, ject. The terms were used by Des Cartes aa well as by his disciples.— H. 2UG ON THE INTELLECTUAL POWERS. £essay ti. human mind which can be called the idea of an external object, he says it is only another word for perception. Chap, v., def. 3. [193] "I take the idea of an object, and the perception of an object, to be the same thing. I do not say whether there may be other things to which the name of idea may be given. But it is certain that there are ideas taken in this sense, and that these ideas are either attributes or modifi- cations of our minds."* This, I think, indeed, was to attack the system of Malebranche upon its weak side, and where, at the same time, an attack was least expected. Philosophers had been so unanimous in maintaining that we do not perceive external objects immediately,-)- but by certain representative images of them called ideas,% that Malebranche might well think his system secure upon that quarter, and that the- only question to be determined was, in what subject those ideas are placed, whether in the human or in the divine mind ? But, says Mr Arnauld, those ideas are mere chimeras — fictions of philosophers ; there are no such beings in nature ; and, therefore, it is to no purpose to inquire whether they are in the divine or in the hu- man mind. The only true and real ideas are our perceptions, which § are acknow- ledged by all philosophers, and by Male- branche himself, to be acts or modifications of our own minds. He does not say that the fictitious ideas were a fiction of Male- branche. He acknowledges that they had been very generally maintained by the scholastic philosophers, || and points out, very judiciously, the prejudices that had led them into the belief of such ideas. Of all the powers of our mind, the > Arnauld did not allow that perceptions and ideas are really or numerically distinguished — i.e., as one thing from another thing ; not even that they are modally distinguished — i. e. t as a thing from Its mode. lie maintained that they azereally identical, and only rationally discriminated as viewed in dif- ferent relations ; the indivisible mental modification being called a 'perception, by reference to the mind or thinking subject— an idea, by reference to the mediate object or thing thought. Arnauld everywhere avows that he denies ideas only as existences distinct from the act itself of perception.— See Oeuvres, t. xxxviii. pp. 187, 198, 199, 389.— H. f Arnauld does not assert against Malebranche, " thaVwe perceive external objects immediately" — that is, in themselves, and as existing. He was too accu- rate for this. By an immediate cognition, Reid means merely the negation of the intermediation of any third thing between the reality perceived and the percipient mind H. t Idea was not the word by which representative images, distinct from the percipient act, had been commonly called j nor were philosophers at all unani- mous in the admission of such vicarious objects.— See Notes G, L, M, N, O, &c.— H. $ That is, Perceptions, (the cognitive acts,> but not Ideas, (the immediate objects of thoieacts.) "The latter were not acknowledged by Malebranche and all phi- losophers to be mere acts or modifications of our own minds H. || But by a diueront name H. external senses are thought to be the best understood, and their objects are the most familiar. Hence we measure other powers by them, and transfer to other powers the language which properly be- longs to them. The objects of sense must be present to the sense, or within its sphere, in order to their being perceived. Hence, by analogy, we are led to say of everything when we think of it, that it is present to the mind, or in the mind. [194] But this presence is metaphorical, or ana- logical only ; and Arnauld calls it objec- tive presence, to distinguish it from that - local presence which is required in objects that are perceived by sense. But both being called by the same name, they are- confounded together, and those things that belong only to real or local presence, are attributed to the metaphorical. We are likewise accustomed to see objects by their images in a mirror, or in water ; and hence are led, by analogy,' to think that objects may be presented to the memory or imagination in some similar manner, by images, whidfphilosopher have called ideas. By such prejudices and analogies, Arnauld conceives, men have been led to believe that the objects of memory and imagination must be presented to the mind by images or ideas ; and the philosophers have been more carried away by these prejudices than even the vulgar, because the use made of this theory was to explain and account for the various operations of the mind — a matter in which the vulgar take no concern. He thinks, however, that Des Cartes had got the better of these prejudices, and that he uses the word idea as signifying the same thing with perception, • and is, therefore, surprised that a disciple of Des Cartes, and one who was so great an admirer of him as Malebranche was, should be carried away by them. It is strange, indeed, that the two most eminent disciples of Des Cartes and his contemporaries should differ so essentially with regard to his doctrine con- cerning ideas. -f- I shall not attempt to give the reader an account of the continuation of this contro- versy between those two acute philosophers, in the subsequent defences and replies ; be- cause I have not access to see them. After much reasoning, and some animosity, each • 1 am convinced that in this interpretation of Des Cartes' doctrine, Arnauld is right ; for Des Cartes defines mental ideas — those, to wit, of which- we are conscious— to be " CogUaliones prout sunt tanquam imagines— that is, thoughts considered in their repre- sentative capacity j nor is there any passage to be found in the writings at thiB philosopher, which, if properly understood, warrants the conclusion, that, by ideas in Vie mind, he meant aught distinct from the cognitive act. The double use of the term idea by Des Cartel has, however, led Reid and others into a miscon- ception on this point. See Note N.— H. t Reid's own doctrine is far more ambiguous.— H. £193, 194] chap, xiii.] OF THE SENTIMENTS Of ANTHONY ARNAULD. 297 continued in his own opinion, and left his antagonist where he found him. [195] Malebranche's opinion of out seeing all things in God, soon died away of itself ; and Arnauld's notion of ideas seems to have been less regarded than it deserved, by the philosophers that came after him ;* per- haps for this reason, among others, that it seemed to be, in some sort, given up by himself, in his attempting to reconcile it to the common doctrine concerning ideas. From the account I have given, one would be apt to conclude that Arnauld totally denied the existence of ideas, in the philosophical sense of that word, and that he adopted the notion of the vulgar, who acknowledge no object of perception but the external object. But he seems very un- willing to deviate so far from the common track, and, what he had given up with one hand, he takes back with the other. For, first, Having defined ideas to be the same thing with perceptions, he adds this qualification to his definition : — " I do not here consider whether there are other things that may be called ideas ; but it is certain there are ideas taken in this sense. ■(- I believe, indeed, there is no philosopher who does not, on some occasions, use the word idea in this popular sense. * The opinion of Arnauld in regard to the nature of ideas wag by no means' overlooked by subsequent philosophers. It is found fully detailed in -almost every systematic course or compend of philosophy, which appeared for a long time after its first promul. gation, and in many. of these it is the doctrine. re- commended as the true. Arnauld's was indeed the opinion which latterly 'prevailed in the Cartesian school. From this it passed into other schools. Leib- nitz, like Arnauld, regarded Ideas, Notions, Repre- sentations, as mere modifications of the mind, (what by his disciples, were called material ideas, like the cerebral ideas of Des Cartes, are out of the question,) and no cruder opinion than this has ever subse- quently found a footing in any of the German systems. " I don't know," says Mr Stewart, " of any author who, prior to Dr Reid, has expressed himself on this subject with so much justness and precision as Father Burner, in the following passage of his Treatise on ■ First Truths :'— " ' If we confine ourselves to what is intelligible in our observations on ideas, we will say, they are no- thing* but mere modifications of the mind as a think- ing being. They are called ideas with regard to the object represented ; and perceptions with regard to the faculty representing. It is manifest that our ideas, considered in this sense, are not more distin- guished than motion is from a body moved.' — (P. 311 jEnalish Translation.)" — t'lem. iii. Add. to vol. i. p. 10. In this passage. Burlier only repeats the doctrine of Arnauld, in Arnauld's own words. Dr Thomas Brown, on the other hand, has en- deavoured to shew that this doctrine, (which he identifies with Reid's,) had been long the catholic opinion ; and that Reid, in his attack on the Ideal system, only refuted what had been already almost universally exploded. In this attempt he is, how- ever, singularly unfortunate ; for, with the excep- tion of Crousaz, all the examples he* adduces to evince the prevalence of Arnauld's doctrine are only so many mistakes, so many instances, in fact, which might be alleged in confirmation of the very opposite conclusion. See Edinburgh Review, vol. Hi., p. 181- 196.-H. f See following note. — H. " [195. 19ci] Secondly, He supports this popular senso of the word by the authority of Des Cartes, who, in his demonstration of the existence of God, from the idea of him in our minds, defines an idea thus : — " By the word idea, I understand that form of any thought, by the immediate perception of which I am conscious of that thought ; so that I can ex- press nothing by words, with understanding, without being certain that there is in my mind the idea of that which is expressed by the words." Thie definition seems, indeed, to be of the same import with that which is given by Arnauld. But Des Cartes adds a qualification to it, which Arnauld, in quoting it, omits ; and which shews that Des Cartes meant to limit his definition to the idea then treated of — that is, to the idea of the Deity ; and that there are other ideas to which this definition does not apply. [ 1 96 ] For he adds: — " And thus I give the name of idea, not solely to the images painted in the phantasy ; nay, in this place, I do not at all give the name of ideas to those images, in so far as they are painted in the corporeal phantasy that is in some part of the brain, but only in so far as they inform the mind, turning its attention to that part of the brain."* Thirdly, Arnauld has employed the whole of his sixth chapter, to shew that these ways of speaking, common among philosophers — to wit, that we perceive not things imme- diately ; that it is their ideas that are the immediate objects of our thoughts; that it is in the idea of everything that'we perceive its properties — are not to be rejected, but are true when rightly understood. He labours to reconcile these expressions to his own definition of ideas, by observing, that every perception and every thought is necessarily conscious of itself, and reflects upon itself ; and that, by this consciousness and reflec- tion, it is its own immediate object. Whence he infers, that the idea — that is, the percep- tion — is the immediate object of perception. This looks like a weak attempt to recon- cile two inconsistent doctrines by one who wishes to hold both.-)- It is true, that con- sciousness always goes along with percep- tion; but they are different operations of the mind, and they have their different objects. Consciousness is not perception, nor is the object of consciousness the object of perception.^ The same may be said of * Des Cartes here refers to the other meaning which he gives to the term idea — that is, to denote the material motion, the organic affeqtion of the main, of which the mind is not conscious. On Reid's mis. apprehension of the Cartesian doctrine touching this matter, see Note N. — H. f Arnauld's attempt is neither weak nor inconsist- ent. He had, in. fact, a clearer view of the condi- tions of the problem than Reid himself, who has, in fact, confounded two opposite doctrines. See Note C. — H. t On Reid's error in reducing consciousness to a special faculty, see Note H.— H. 208 ON THE INTELLECTUAL POWERS. [_ESSAY II. every operation of mind that has an object. Thus, injury is the object of resentment. When I resent an injury, I am conscious of my resentment — that is, my resentment is the immediate and the only object of my consciousness ; but it would be absurd to infer from this, that my resentment is the immediate object of my resentment. [197] Upon the whole, if Arnauld— in conse- quence of his doctrine, that ideas, taken for representative images of external ob- jects, are a mere fiction of the philosophers — had rejected boldly the doctrine of Des Cartes, as well as of the other philosophers, concerning those fictitious beings, and all the ways of speaking that imply their ex- istence, I should have thought him more consistent with himself, and his doctrine concerning ideas more rational and more intelligible than that of any other author of my acquaintance who has treated of the subject.* CHAPTER XIV. REFLECTIONS ON THE COMMON THEORY OF IDEAS. After so long a detail of the sentiments of philosophers, ancient and modern, con- cerning ideas, it may seem presumptuous to call in question their existence. But no philosophical opinion, however ancient, however generally received, ought to rest upon authority. There is no presumption in requiring evidence for it, or in regulat- ing our belief by the evidence we can find. To prevent mistakes, the reader must again be reminded, that if by ideas are meant only the acts or operations of our minds in perceiving, remembering, or ima- gining objects, I am far from calling in question the existence of those acts ; we are conscious of them every day and every hour of life; and I believe no man of a sound mind ever doubted of the real exist- ence of the operations of mind, of which he is conscious. Nor is it to be doubted that, by the faculties which God has given us, we can conceive things that are absent, as well as perceive those that are within the reach of our senses ; and that such concep- tions may be more or less distinct, and ■ Reids discontent with Arnauld s opinion — an opinion which is stated with great perspicuity by its author — may be used as an argument to shew that his own doctrine is, however ambiguous, that of intui. tive or immediate perception. (SeeNoteC) Amauld's theory is identical with the finer fomvof representa- tive or mediate perception, and the difficulties of Ulat doctrine were not overlooked by his great antagonist. Arnauld well objected that, when we see a horse, ac- cording to Malebranche, what we see is in reality God. himself; but Malebrauche Well rejoined, that, when we see a horse,- according to Arnauld, what we tiee is, i a reality, only a modification of ourselves.— H. more or less lively and strong. We have reason to ascribe to the all-knowing and all-perfect Being distinct conceptions of all things existent and possible, and of all their relations ; and if these conceptions are called his eternal ideas, there ought to he no dis- pute among philosophers about a word. [198] The ideas, of whose existence I require the proof, are not the operations of any mind, but supposed objects of those operations. They are not perception, re- membrance, or conception, but things that are said to be perceived, or remembered, or imagined. Nor do I dispute the existence of what the vulgar call the objects of perception. These, by all who acknowledge their exist- ence, are called real things, not ideas. But philosophers maintain that, besides these, there are immediate objects of perception in the mind itself : that, for instance, we do not see the sun immediately, but an idea ; or, as Mr Hume calls it, an impres- sion in our own minds. This idea is said to be the image, the resemblance, the re- presentative of the .sun, if there be a sun. It is from the existence of the idea that we must infer the existence of the sun. But the idea, being immediately perceived, there can be no doubt, as philosophers think, of its existence. In like manner, when I remember, or when I imagine anything, all men acknow- ledge that there must be something that is remembered, or that is imagined ; that is, some object of those operations. The object remembered must be something that did exist in time past : the object imagined may be something that never existed.* But, say the philosophers, besides these objects which all men acknowledge, there is a more immediate object which really exists in the mind at the same time we remember or imagine. This object is an idea or image of the thing remembered or imagined. The first reflection I would make on this philosophical opinion is, that it is directly contrary to the universal sense of men who have not been instructed in philosophy. When we see the sun or moon, we have no doubt that the very objects which we im- mediately see are very far distant from us, and from one another. We have not the least doubt that this is the sun and moon which God created some thousands of years ago, and which have continued to perform their revolutions in the heavens ever since. [199] But how are we astonished when the philosopher informs us that we are mis- taken in all this ; that the sun and moon which we see are not, as we imagine, many miles distant from us, and from each other, » • See Note B H £W-I99] ohap. xiv.] REFLECTIONS ON THE THEORY OF IDEAS. 299 but that they are in our own mind ; that they had no existence before we saw them, and will have none when we cease to per- ceive and to think of them; because the objects we perceive are only ideas in our own minds, which can have no existence a moment longer than we think of them !* If a plain man, uninstructed in philoso- phy, has faith to receive these mysteries, how great must be his astonishment ! He is brought into a new world, where every- thing he sees, tastes, or touches, is an idea — a fleeting kind of being which he can con- jure into existence, or can annihilate in the twinkling of an eye. After his mind is somewhat composed, it will be natural for him to ask his philoso- phical instructor, Pray, sir, are there then no substantial and permanent beings called the sun and moon, which continue to exist whether we think of them or not ? Here the philosophers differ. Mr Locke, and those that were before him, will answer to this question, that it is very true there are substantial and permanent beings called the sun and moon ; but they never appear to us in their own person, but by their re- presentatives, the ideas in our own minds, and we know nothing of them but what we can gather from those ideas. Bishop Berkeley and Mr Hume would give a different answer to the question pro- posed. They would assure the querist that it is a vulgar error, a mere prejudice of the ignorant and unlearned, to think that there are any permanent and substantial beings called the sun and moon ; that the heavenly bodies, our own bodies, and all bodies what- soever, are nothing but ideas in our minds ; and that there can be nothing like the ideas of one mind, but the ideas of another mind. [200] There is nothing in nature but minds and ideas, says the Bishop; — nay, says Mr Hume, there is nothing in nature but ideas only ; for what we call a mind is nothing but a train of ideas connected by certain relations between themselves. In this representation of the theory of ideas, there is nothing exaggerated or mis- represented^ far as I am able to judge ; and surely nothing farther is necessary to shew that, to the uninstructed in philoso- phy, it must appear extravagant and vision- ary, and most contrary to the dictates of common understanding. There is the less need of any farther proof of this, that it is very amply aeknow- • Whether Eeid himself do not virtually hold thi 8 last opinion, see Note C. At any rate, it is very in- correct to say that the sun, moon, &c. , are, or can be* perceived-by ub as existent, and in. their real -dis- tance in the heavens ; all that we can be cognisant of (supposing that we are immediately percipient of the non-ego) is the rays of .light emanating from them, and in contact and relation with our organ of sight. f200, 201] ledged by Mr Hume in his Essay on tha Academical or Sceptical Philosophy. " It seems evident," says he, " that men are car- ried, by a natural instinct or prepossession, to repose faith in their senses; and that, without any reasoning, or even almost be- fore the use of reason, we always suppose an external universe, which depends not on our perception, but would exist though we and every sensible creature were absent , or annihilated. Even the animal creation are governed by a like opinion, and preserve this belief of external objects in all their thoughts, designs, and actions." " It seems also evident that, when men follow this blind and powerful instinct of nature, they always suppose the very im- ages presented by the senses to be the ex- ternal objects, and never entertain any suspicion that the one are nothing but re- presentations of the other. This very table which we see white, and feel hard, is be- lieved to exist independent of our percep- tion, and to be something external to the mind which perceives it ; our presence be- stows not being upon it ; our absence anni- hilates it not : it preserves its existence uniform and entire, independent of the situ- ation of "intelligent beings who perceive or contemplate it. [201] "..But this universal and primary notion of all men is soon destroyed by the slightest philosophy, which teaches us that nothing can ever be present to the mind, but an image or perception ; and that the senses are only the inlets through which these images are received, without being ever able to produce any immediate intercourse between the mind and the object." It is therefore acknowledged by this phi- losopher, to be a natural instinct or pre- possession, an universal andprimary opinion of all men, a primary instinct of nature, that the objects which we immediately perceive by our senses, are not images in our minds, but external objects, and that their exist- ence is independent of us and our percep- tion. In this acknowledgment, Mr Hume in- deed seems to me more generous, and even more ingenuous than Bishop Berkeley, who would persuade us that his opinion does not oppose the vulgar opinion, but only that of the philosophers ; and that the external existence of a material world is a philoso- phical hypothesis, and not the natural dic- tate of our perceptive powers. The Bishop shews a timidity of engaging such an adver- sary, as a primary and universal opinion of all men. He is rather fond to court its pa- tronage. Butthe philosopher intrepidly gives a defiance to this antagonist, and seems to glory inaconflict that was worthy of his arm. Optat aprum aut fulvurn descendere monte leonem. After all, I suspect that a philo- 300 ON THE INTELLECTUAL POWERS. [_ESSAY it. Bopher who wages war with this adversary, will find himself in the same condition as a mathematician who should undertake to demonstrate that there is no truth in the axioms of mathematics. A second reflection upon this subject is— that the authors who have treated of ideas, have generally taken their existence for granted, as a thing that could not be called in question ; and such arguments as they have mentioned incidentally, in order to prove it, seem too weak to support the con- clusion. [202] Mr Locke, in the introduction to his Essay, tells us, that he uses the word idea to signify whatever is the immediate object of thought ; and then adds," (C I presume it will be easily granted me that there are such ideas in men's minds; every one is conscious of them in himself; and men's words and actions will satisfy him that they are in others." I am indeed conscious of perceiving, remembering, imagining; but that the objects of these operations are images in my mind, I am not conscious. I am satisfied, by men's words and actions, that they often perceive the same objects which I perceive, which could not be, if those objects were ideas in their own minds. Mr Norris is the only author I have met with, who professedly puts the question, Whether material things can be perceived by us immediately ? He has offered four arguments to shew that they cannot. First, " Material objects are without the mind, and therefore there can be no union between the object and the percipient." Answer, This argument is lame, until it is shewn to be necessary that in perception there should be a union between the object and the per- cipient. Second, " Material objects are disproportioned to the mind, and removed from it by the whole diameter of Being." This argument I cannot answer, because I do not understand it.' Third, "Because, * This confession would, of itself, prove how super, ficially Reid was versed in the literature of philo- sophy. Norris's .second argument is only the state- ment of a principle generally assumed by philosophers — that the relation of knowledge infers a correspond- ence of nature between the subject knowing, and the object known. This principle has, perhaps, exerted a more extensive influence on speculation than any other ; and yet it has not been proved, and is incapable of proof— nay, is contradicted by the evidence of consciousness itself. To trace the influence of this assumption would be, in fact, in a certain sort, to write the history of philosophy ; for, though this in- fluence has never yet been historically devel< ped, it would be easy to shew that the belief, explicit or implicit, that what knows and what is imme- diately known must be "of an analogous nature, lies at the root of almost every theory of cognition, from the very earliest to the very latest speculations. In the more ancient philosophy of Greece, three philo- sophers (Anaxagoras, Heraclitus, and Alcmffi m) are found, who professed the opposite doctrine— thai the condition of knowledge lies in the contrariety, in the natural antithesis, of subject and object. Aristotle, likewise, in his treatise On the Soul, expressly coa- dermis the prevalent opinion, that the similar is only if material objects were immediate objects of perception, there could be no physical science — things necessary and immutable being the only object of science." Answer, Although things necessary and immutable be not the immediate objects of perception, they may be immediate objects of other powers of the mind. Foui th, " If material things were perceived by themselves, they would be a true light to our minds, as being the intelligible form of our understandings, and consequently perfective of them, and indeed superior to them." If I comprehend anything of this mysterious argument, it follows from it, that the Deity perceives nothing at all, because nothing can be supe- rior to his understanding, or perfective of it. [203] There is an argument which is hinted at by Malebranche, and by several other authors, which deserves to be more seriously considered. As I find it most clearly ex- pressed and most fully urged by Dr Samuel Clarke, I shall give it in his words, in his second' reply to Leibnitz, § 4. " The soul, without being present to the images of the things perceived, could not possibly perceive them. A living substance can only there perceive, where it is present, either to the cognisable by the similar; but, in his Nicomochian Ethics, he reverts to the doctrine which, in the for- mer work, he had rejected. With these exceptions, no principle, since the time of Empedocles, by whom it seems first to have been explicitly announced, has been more universally received, than this— that the relation of knowledge infers an analogy of existence. This analogy may be of two degrees. What knows, and wliat is known, may be either similar or the same ; and, it the principle itself be admitted, the latter alternative is the more philosophical. 'Without entering on details, I may here notice some of the more remarkable results of this principle, in both its degrees. The general principle, not, indeed, exclu. sively, but mainly, determined the admission of a representative perception, by disallowing the possibil- ity of any consciousness, or immediate knowledge of matter, by a nature so different from it as mind ; and, in its two degrees, it determined thevarious hy- potheses, by which it was attempted to explain the possibility of a representative or mediate perception of the external world. To this principle, iu its lower potence— that what knows must be similar in nature to what is immediately known— we owe the intentional species of the Aristotelians, and the ideas of Malebranche and Berkeley. From this principle, in its higher potence— that what knows must be identical in nature with what is immediately known — there flow the gnostic reasons of the Flatonists, the pre-eafeUngfornis or species of Theophta&tus and The. mistius, of Adelandus and Avicenna, the (mental) ideas of Des Cartes and Arnauld, the representations, sensual ideas, $c. of Leibnitz and Wolf, the phceno- mena of Kant, the states of Brown, and (shall we say ?} the vacillating doctrine of perception held by Reid himself. Mediately, this principle was the origin of many other famous theories :— of the hier. archical gradation of souls or faculties of the Aristo- telians ; of the vehicular media of the Platonists ; of the hypotheses of a common intellect of Alex- ander, Themistius, Averroes, Cajetanus, and Zabar- ella j ofthe vision in the deity of Malebranche; andof the Cartesian and I3±-23Gl any argument to prove their existence. But, if it is true that by our senses we have not only a variety of sensations, but likewise a conception and an immediate natural con- viction of external objects, he reasons from a false supposition, and his ' arguments fall to the ground.* CHAPTER XVII. OF THE OBJECTS OF PERCEPTION ; AND, FIRST, OF PRIMARY AND SECONDARY QUALITIES. The objects of perception are the various qualities of bodies. Intending to treat of these only in general, and chiefly with a view to explain the notions which our senses give us of them, I begin with the distinction between primary and secondary qualities. These were distinguished very early. The Peripatetic system confounded them, and left no difference. The distinction was again revived by Des Cartes and Locke, and a second time abolished by Berkeley and Hume. If the real foundation of this dis- tinction can be pointed out, it will enable us to account for the various revolutions in the sentiments of philosophers concerning it. Every one knows that extension, divisi- bility, figure, motion, solidity, hardness, softness, and fluidity, were by Mr Locke called primary qualities of body ; and that sound, colour, taste, smell, and heat or cold, were called &econdary qualities. Is there a just foundation for this distinction ? Is there anything common to the primary which belongs not to the secondary ? And what is it ? I answer, That there appears to me to be a real foundation for the distinction ; and it is this — that our senses give us a direct and a distinct notion of the primary qualities, and inform us what they are in themselves.-!* But of the secondary qualities, our senses give us only a relative and obscure notion. [236] They inform us only, that they are qualities that affect us in a certain manner — that is, produce in us a certain sensation ; but as to what they are in themselves, our senses leave us in the dark.:}: * On this whole distinction, see Note D. * . — H t By the expression, " what they are in tiieinselves, ' in reference to the primary qualities, and of " rela- tivt lotion" in reference to the secondary, Reid cannot mean that the former are known to us abso* lutely and in themselves— that is, out of relation to our cognitive faculties j fnr he elsewhere admits that all our knowledge is relative. Farther, if *' our senses give us a direct and distinct notion of the piimary qualities ""d inform \ s what they are in themselves," these qualities, as known, must resemble* or be iden- tical with, these qualities as existing. — H. X The distinctions or nercepiion and sensation, and of primary and secondary qualities, may be reduced to one higher princ pie. Knowledge ispartly object* ive, partly subjective,- both these elements are essen- tial to every cognition, but in every cognition they are always in the inverse raiio of e 314 ON THK INTELLECTUAL POWERS. [essay II, Every man capable of reflection may easily satisfy himself that he has a perfectly- clear and distinct notion of extension, divisi- bility, figure, and motion. The solidity of a body means no more but that it excludes other bodies from occupying the same place at the same time Hardness, softness, and fluidity are different degrees of cohesion in the parts of a body. It is fluid when it has no sensible cohesion ; soft, when the cohe- sion is weak ; and hard, when it is strong. Of the cause of this cohesion we are ignor- ant, but the thing itself we understand per- fectly, being immediately informed of it by the sense of touch. It is evident, therefore, that of the primary qualities we have a clear and distinct notion ; we know what they are, though we may be ignorant of their causes. I observed, farther, that the notion we have of primary qualities is direct, and not relative only. A relative notion of a thing, is, strictly speaking, no notion of the thing at all, but only of some relation which it bears to something else. Thus, gravity sometimes signifies the tend- ency of bodies towards the earth ; some- times it signifies the cause of that tendency. When it means the first, I have a direct and distinct notion of gravity ; I see it, and feel it, and know perfectly what it is ; but this tendency must have a cause. We give the same name to the cause ; and that cause has been an object of thought and of specu- lation. Now, what notion have we of this cause when we think and reason about it ? It is evident we think of it as an unknown cause, of a known effect. This is a relative notion ; and it must be obscure, because it gives us no conception of what the thing is, but of what relation it bears to something else. Every relation which a thing un- known bears to something that is known, may give a relative notion of it ; and there are many objects of thought and of dis- course of which our faculties can give no better than a relative notion. [237] Having premised these things to explain what is meant by a relative notion, it is evi- dent that our notion of primary qualities is not of this kind ; we know what they are, and not barely what relation they bear to something else. It is otherwise with secondary qualities. If you ask me, what is that quality or mo- dification in a rose which I call its smell, I am at a loss to answer directly. Upon re- flection, I find, that I have a distinct notion of the sensation which it produces in my mind. But there can be nothing like to this sensation in the rose, because it is in- in perception and Ibeprimary qualities, tlieobjective do rtcnt preponderates, whereas the subjective ele- ment preponderates in sensation and the secondary SOalitirs. See Netcs 1) and D * .— II. sentient. The quality in the rose is some- thing which occasions the sensation in me ; but what that something is, I know not. My senses give me no information upon this point. The only notion, therefore, my senses give is this — that smell in the rose is an unknown quality or modification, which is the cause or occasion of a sensation which I know well. The relation which this un- known quality bears to the sensation with which nature hath connected it, is all I learn from the sense of smelling ; but this is evidently a relative notion. The same rea- soning will apply to every secondary quality. Thus, I think it appears that there is a real foundation for the distinction of pri- mary from secondary qualities ; and that they are distinguished by this — that of the primary we have by our senses a direct and distinct notion ; but of the secondary only a relative notion, which must, because it is only relative, be obscure ; they are con- ceived only as the unknown causes or occa- sions of certain sensations with which wo are well acquainted. The account I have given of this distinc- tion is founded upon no hypothesis. [238] Whether our notions of primary qualities are direct and distinct, those of the se- condary relative and obscure, is a matter of fact, of which every man may have cer- tain knowledge by attentive reflection upon them. To this reflection I appeal, as the proper test of what has been advanced, and proceed to make some reflections on this subject. 1- The primary qualities are neither sens- ations, nor are they resemblances of sens- ations. This appears to me self-evident. I have a clear and distinct notion of each of the primary qualities. I have a clear and distinct notion of sensation. I can com- pare the one with the other ; and, when I do so, I am not able to discern a resembling feature. Sensation is the act or the feeling (I dispute not which) of a sentient being. Figure, divisibility, solidity, are neither acts nor feelings. Sensation supposes a sentient being as its subject ; for a sensa- tion that is not felt by some sentient being, is an absurdity. Figure and divisibility supposes a subject that is figured and divi- sible, but not a subject that is sentient. 2. We have no reason to think that any of the secondary qualities resemble any sens- ation. The absurdity of this notion has been clearly shewn by Des Cartes, Locke, and many modern philosophers. It was a tenet of the ancient philosophy, and is still by many imputed to the vulgar, but only as a vulgar error. It is too evident to need proof, that the vibrations of a sounding body do not resemble the sensation of sound, nor the effluvia of an odorous body the sens- ation of smell. [ 237, 2381 CHAP. XV11.] OF THE OBJECTS OF PERCEPTION. 315 3. The distinctness of our notions of pri- mary qualities prevents all questions and disputes about their nature. There are no different opinions about the nature of ex- tension, figure, or motion, or the nature of any primary quality. Their nature is man- ifest to our senses, and cannot be unknown to any man, or mistaken by him, though their causes may admit of dispute. [239] The primary qualities are the object of the mathematical sciences; and the dis- tinctness of our notions of them enables us to reason demonstratively about them to a great extent. Their various modifications are precisely defined in the imagination, and thereby capable of being compared, and their relations determined with precision and cer- tainty. It is not so with secondary qualities. Their nature not being manifest to the sense, maybe a subject of dispute. Our feeling informs us that the fire is hot ; but it does not inform us what that heat of the fire is. But does it not appear a contradiction, to say we know that the fire is hot, but we know not what that heat is ? I answer, there is the same appearance of contradic- tion in many things that must be granted. We know that wine has an inebriating qua- lity ; but we know not what that quality is. Jt is true, indeed, that, if we had not some notion of what is meant by the heat of fire, and by an inebriating quality, we could affirm nothing of either with understand- ing. We have a notion of both ; but it ■ is only a relative notion. We know that they are the causes of certain known effects. 4. The nature of secondary qualities is a proper subject of philosophical disquisition ; and in this philosophy has made some pro- gress. It has been discovered, that the sensation of smell is occasioned by the effluvia of bodies; that of sound by their vibration. The disposition of bodies to re- flect a particular kind of light, occasions the sensation of colour. Very curious dis- coveries have been made of the nature of heat, and an ample field of discovery in these subjects remains. 5. We may see why the sensations be- longing to secondary qualities are an object of our attention, while those which belong to the primary are not. The first are not only signs of the ob- ject perceived, but they bear a capital part in the notion we form of it. [240] We conceive it only as that which occasions such a sensation, and therefore cannot reflect upon it without thinking of the sensation which it occasions : we have no other mark whereby to distinguish it. The thought of a secondary quality, therefore, always car- ries us back to the sensation which it pro- duces. We give the same *name to both, and are apt to confound them together. r239-21ll But, having a clear and distinct conception of primary qualities, we have no need, when we think of them, to recall their sensations. When a primary quality is perceived, the sensation immediately leads our thought to the quality signified by it, and is itself for- got. We have no occasion afterwards to reflect upon it ; and so we come to be as little acquainted with it as if we had never felt it. This is the case with the sensations of all primary qualities, when they are not so painful or pleasant as to draw our atten- tion. When a man moves his hand rudely against a pointed hard body, he feels pain, and may easily be persuaded that this pain is a sensation, and that there is nothing resembling it in the hard body ; at the same time, he perceives the body to be hard and pointed, and he knows that these qualities belong to the body only. In this case, it is easy to distinguish what he feels from what he perceives. Let him again touch the pointed body gently, so as to give him no pain ; and now you can hardly persuade him that he feels anything but the figure andhardness of the body : so difficult it is to attend to the sens- ations belonging to primary qualities, when they are neither pleasant nor painful. They carry the thought to the external object, and immediately disappear and are forgot. Nature intended them only as signs ; and when they have served that purpose they vanish. We are now to consider the opinions both of the vulgar and of philosophers upon this subject. [241] As to the former, it is not to be expected that they should make distinctions which have no connection with the common affairs of life ; they do not, therefore, distinguish the primary from the secondary qualities, but speak of both as being equally qualities of the external ob- ject. Of the primary qualities they have a distinct notion, as they are immediately and distinctly, perceived by the senses ; of the secondary, their notions, as I apprehend, are confused and indistinct, rather than erroneous. A secondary quality is the unknown cause or occasion of a well-known effect ; and the same name is common to the cause and the effect. Now, to dis- tinguish clearly the different ingredients of a complex notion, and, at the same time, the different meanings of an ambiguous word, is the work of a philosopher ; and is not to be expected of the vulgar, when their occasions»do not require it, I grant, therefore, that the notion which the vulgar have of secondary qualities, is indistinct and inaccurate. But there seems to be a contradiction between the vulgar and the philosopher upon this subject, and each charges the other with a gross al> 316 ON THE INTELLECTUAL POWER?. |_1!SSAY II, surdity. The vulgar say, that fire is hot, and snow cold, and sugar sweet ; and that to deny this is a gross absurdity, and con- tradicts the testimony of our senses. The philosopher says, that heat, and cold, and sweetness, are nothing but sensations in our minds ; and it is absurd to conceive that these sensations are in the fire, or in the snow, or in the sugar. I believe this contradiction, between the vulgar and the philosopher, is more apparent than real ; and that it is owing to an abuse of language on the part of the philosopher, and to indistinct notions on the part of the vulgar. The philosopher says, there is no heat in the fire, meaning that the fire has not the sensation of heat. His meaning is just; and the vulgar will agree with him, as soon as they understand his meaning : But his language is improper ; for there is really a quality in the fire, of which the proper name is heat ; and the name of heat is given to this quality, both by philosophers and by the vulgar, much more frequently than to the sensation of heat. [242] This speech of the philosopher, therefore, is meant by him in one sense ; it is taken by the vulgar in another sense. In the sense in which they take it, it is indeed absurd, and so t'.iey hold it to be. In the sense in which he means it, it is true ; and the vulgar, as soon as they are made to understand that sense, will acknowledge it to be true. They know, as well as the philosopher, that the fire does not feel heat : and this is all that he means by saying there is no heat in the fire.* In the opinions of philosophers about primary and secondary qualities, there have been, as was before observed, several revo- lutions, -f* They were distinguished, long be- fore the days of A ristotle, by the sect called Atomists : among whom Democritus made a capital figure. Iu those times, the name of quality was applied only to those we call secondary qualities ; the primary, being con- sidered as essential to matter, were n t called qualities. X That the atoms, which they held to be the first principles of things, were extended, solid, figured, and movable, there was no doubt ; but the question was, whether they had smell, taste, and colour ? or, as it was commonly expressed, whether they had qualities ? The Atomists main- tained, that they had not ; that the quali- ties were not in bodies, but were something resulting from the operation of bodies upon our senses. § * All this ambiguity was understood and articu. lately explai edby Conner philos >phers. See abovr, notes at pp 20.5 and 31", and No'e D.— H. tSee N.ite D H. X The Atomists derived the qualitative attributes of things troin the quantitative — H. i, Still Democritus suppose I certain real or ob- jective causes tor tliesubj-ct . e di'lorences of our It would seem that, when men began to speculate upon this subject, the primary qualities appeared so clear and manifest that they could entertain no doubt of their existence wherever matter existed ; but the secondary so obscure that they were at a loss where to place them. They used this comparison : as fire, which is neither in the flint nor in the steel, is produced by their collision, so those qualities, though not in bodies, are produced by their impulse upon our senses. [243] This doctrine was opposed by- Aristotle.* He believed taste and colour to be substan- tial forms of bodies, and that their species, as well as those of figure and motion, are received by the senses. ■)■ In believing that what we commonly call taste and colour, is something really inherent in body, and does not depend upon its being tasted and seen, he followed nature. But, in believing that our sensations of taste and colour are the forms or species of those qualities received by the senses, he followed his own theory, which was an ab- surd fiction. -f- Des Cartes not only shewed the absurdity of sensible species received by the senses, but gave a more just and more intelligible account of secondary qualities than had been given before. Mr Locke followed him, and bestowed much pains upon this subject. He was the first, I think, that gave them the name of secondary qualities,} which has been very generally adopted. He distinguished the sensation from the quality in the body, which is the cause or occasion of that sensation, and shewed that there neither is nor can be any similitude between them.§ By this account, the senses are acquitted of putting any fallacy upon us ; the sensation is real, and no fallacy ; the quality in the body, which is the cause or occasion of this sensation, is likewise real, though the nature of it is not manifest to our senses. If we impose upon ourselves, by confounding the fensation with the quality that occasions it, this is owing to rash judgment or weak understanding, but not to any false testi- mony of our senses. This account of secondary qualities I take sensations Thus, in the different forms, positions, and relations of atoms, he sought the ground of difference of tastes, colours, heat and cold, &c. See Theophrastus Be Sensu, f, (i5 —Aristotle Be Anima, iii 2. — Galen Be Elementis— Simplicius in Phys. Auscult libros, t I itl, b.— H * Aristotle admitted that the doctrine in question was true, of colour, taste, &c , as 2Br ' iyigyuuv, hut not true of them as *«,-« iuntiur. See be Anima iu.2 H. ^ t This is rot really Aristo'le's doctrine.— H. t Locke only gave a new meaning to old terms. 1 he first and second or the primary and secondary qualities of Aristotle, denoted a distinction similar to, but not identical with, that in question— H. $ He distinguished nothing which had not been more precisely di. criminated by Aristotle and the t artesians. — H. [21-2, 24.1] CHAP. XVII, J OF THE OBJECTS OF PERCEPTION". 317 to be very just ; and if Mr Locke had stopped here, he would have left the matter very clear. But he thought it necessary to introduce the theory of ideas, to explain the distinction between primary and secondary qualities, and by that means, as I think, perplexed and darkened it. When philosophers speak about ideas, we are often at a loss to know what they mean by them, and may be apt to suspect that they are mere fictions, that have no exist- ence. [244] They have told us, that, by the ideas which we have immediately from our senses, they mean our sensations.* These, indeed, are real things, and not fictions. We may, by accurate attention to them, know perfectly their nature ; and, if philo- sophers would keep by this meaning of the word idea, when applied to the objects of sense, they would at least be more intelli- gible. Let us hear how Mr Locke explains the nature of those ideas, when applied to primary and secondary qualities, Book 2, chap 8, § 7) tenth edition. " To discover the nature of our ideas the better, and to discourse of them intelligibly, it will be con- venient to distinguish them, as they are ideas, or perceptions in our minds, and as they are modifications of matter in the bodies that cause such perceptions in us, that so we may not think (as perhaps usually is done) that they are exactly the images and resemblances of something inherent in the subject ; most of those of sensation beinji', in the mind, no more the likeness of some- thing existing without us, than the names that stand for them are the likeness of our ideas, which yet, upon hearing, they are apt to excite in us." This way of distinguishing a thing, first, as what it is ; and, secondly, as what it is not, is, I apprehend, a, very extraordinary way of discovering its nature.-f And if ideas are ideas or perceptions in our minds, and, at the same time, the modifications of mat- ter in the bodies that cause such percep- tions in us, it will be no easy matter to discourse of them intelligibly. The discovery of the nature of ideas is carried on in the next section, in a manner no less extraordinary. tC Whatsoever the mind perceives in itself, or is the immediate object of perception, thought, or under- standing, that I call idea ; and the power to produce any idea in our mind, I call quality of the subject wherein that power is. Thus, a snowball having the power to produce in us the ideas of white, cold, and round — the powers to produce those ideas • The Cartesians, particularly Malebranche, dis. tinguished the Idea and the Feeling (sentiment, sensa- tio.J Of the primary qualities in their doctrine we have Ideas; of the secondary, only Feelings.— H. t This and t-oine of the following strictures on Locke are rather hypercritical. — H. [241-246 1 in us, as they are in the snowball, I call qualities ; and, as they are sensations, or perceptions in our understandings, I call them ideas ; which ideas, if I speak of them sometimes as in the things themselves, I would be understood to mean those quali- ties hi the objects which produce them in us." [245] These are the distinctions which Mr Locke thought convenient, in order to dis- cover the nature of our ideas of the quali- ties of matter the better, and to discourse of them intelligibly. I believe it will be difficult to find two other paragraphs in the essay so unintelligible. Whether this is to be imputed to the intractable nature of ideas, or to an oscitancy of the author, with which he is very rarely chargeable, I leave the reader to judge. There are, indeed, seve- ral other passages in the same chapter, in which a like obscurity appears ; but I do not chuse to dwell upon them. The con- clusion drawn by him from the whole is, that primary and secondary qualities are distinguished by this, that the ideas of the former are resemblances or copies of them, but the ideas of the other are not resem- blances of them. Upon this doctrine, I beg leave to make two observations. First, Taking it for granted that, by the ideas of primary and secondary qualities, he means the sensations* they excite in us, I observe that it appears strange, that a sensation should be the idea of a quality in body, to which it is acknowledged to bear no resemblance. If the sensation of sound be the idea of that vibration of the sound- ing body which occasions it, a surfeit may, for the same reason, be the idea of a feast. A second observation is, that, when Mr Locke affirms, that the ideas of primary qualities — that is, the sensations* they raise in us — are resemblances of those qualities, he seems neither to have given due atten- tion to those sensations, nor to the nature of sensation in general. [246] Let a man press his hand against a hard body, and let him attend to the sensation he feels, excluding from his thought every thing external, even the body that is the cause of his feeling. This abstraction, in- deed, is difficult, and seems to have been i little, if at all practised. But it is not im- possible, and it is evidently the only way to understand the nature of the sensation. A due attention to this sensation will satisfy » Here, as formerly, {vide supra, notes at pp 208, 290, &c.,) Reid will insist on giving a more limited meaning to the term Sensation than Locke did, and on criticising him by that imposed meaning. The Sensation of Locke was equivalent to the Sensation and Perception of Reid. It is to be observed that Locke did not, like the Cartesians, distinguish the Idea (corresponding to Reid's Perception) from the Feeling (sentiment, sens tio) corresponding to Reid'l Sensation.— 11 318 ON THE INTELLECTUAL POWERS. [[essay II him tnat it is no more like hardness in a body than the sensation of sound is like vibration in the sounding body. I know of no ideas but my conceptions ; and my idea of hardness in a body, is the conception of such a cohesion of its parts as requires great force to displace them. I have both the conception and belief of this quality in the body, at the same time that I have the sensation of pain, by pressing my hand against it. The sensation and perception are closely conjoined by my constitution ; but I am sure they have no similitude ; I know no reason why the one should be called the idea of the other, which does not lead us to call every natural effect the idea of its cause. Neither did Mr Locke give due attention to the nature of sensation in general, when he affirmed that the ideas of primary qua- lities — that is, the sensations* excited by them— are resemblances of those quali- ties. That there can be nothing like sensation in an insentient being, or like thought in an unthinking being, is self-evident, and has been shewn, to the conviction of all men that think, by Bishop Berkeley ; yet this was unknown to Mr Locke. It is an humbling consideration, that, in subjects of this kind, self-evident truths may be hid from the eyes of the most ingenious men. But we have, withal, this consolation, that, when once discovered, they shine by their own light : and that light can no more be put out. [247] Upon the whole, Mr Locke, in making secondary qualities to be powers in bodies to excite certain sensations in us, has given a just and distinct analysis of what our senses discover concerning them ; but, in applying the theory of ideas to them and to the primary qualities, he has been led to say things that darken the subject, and that will not bear examination. -J* Bishop Berkeley having adopted the sen- timents common to philosophers, concern- ing the ideas we have by our senses — to wit, that they are all sensations — saw more clearly the necessary consequence of this doctrine; which is, that there is no material world — no qualities primary or secondary — and, consequently, no foundation for any dis- tinction between them.$ He exposed the absurdity of a resemblance between our » No ; not Sensations in Reiti's meaning ; but Per- cepts — the immediate objects we ate conscious of in the cognitions of sense.— H. 1 The Cartesians did not apply the term ideas to our sensations of the secondary qualities. — H. J See above, p. 142, note *. The mere distinction of primary and secondary qualities, of perception and sensation, is of no importance against Idealism, if the primary qualities as immediately perceived, (i e. as k'own tn consciousness,) be only conceptions, no- tions, or modit-cations of mil d itselt. See following Ni.te.-H. sensations and any quality, primary or secondary, of a substance that is supposed to be insentient. Indeed, if it is granted that the senses have no other office but to furnish us with sensations, it will be found impossible to make any distinction between primary and secondary qualities, or even to maintain the existence of a material world. From the account I have given of the various revolutions in the opinions of philo- sophers about primary and secondary qua- lities, I think it appears that all the dark- ness and intricacy that thinking men have found in this subject, and the errors they have fallen into, have been owing to the difficulty of distinguishing clearly sensa- tion from perception — what we feel from what we perceive. The external senses have a double pro- vince — to make us feel, and to make us perceive. They furnish us with a variety of sensations, some pleasant, others painful, and others indifferent ; at the same time, they give us a conception and an invincible belief of the existence of external objects. This conception of external objects is the work of nature. The belief of their exist- ence, which our senses give, is the work of nature; so likewise is the sensation that accompanies it. This conception and be- lief which nature produces by means of the senses, we call perception.* [248] The feeling which goes along with the percep- tion, we call sensation. The perception and its corresponding sensation are produced at the same time. In our experience we never find them disjoined. Hence, we are led to consider them as one thing, to give them one name, and to confound their different attributes. It becomes very difficult to separate them in thought, to attend to each by itself, and to attribute nothing to it which belongs to the other. To do this, requires a degree of attention to what passes in our own minds, and a talent of distinguishing things that differ, which is not to be expected in the vulgar, and is even rarely found in philosophers ; so that the progress made in a just analysis of the operations of our senses has been very slow. The hypothesis of ideas, so generally adopted, hath, as I apprehend, greatly retarded this progress, and we might hope for a quicker advance, if philosophers could so far humble themselves as to be- lieve that, in every branch of the philosophy of nature, the productions of human fancy and conjecture will be found to be dross ; and that the only pure metal that will en- dure the test, is what is discovered by patient observation and chaste induction. * If the conception, like the odief, be subjectfre in perception, we have no refuge from Idealism in this doctrine. Sre above, the notes at pp. 128.130, 183, &c, and Nolo C H. [217, 21S] chap, xviiij OF OTHER OBJECTS OF PERCEPTION. 319 CHAPTER XVIII. UF OTHEll OBJECTS OF PERCEPTION. Besides primary and secondary qualities of bodies, there are many other immediate objects of perception. Without pretending to a complete enumeration, I think they mostly fall under one or other of the follow- ing, classes. Is', Certain states or condi- tions of our own bodies. 2d, Mechanical powers or forces. 3rf, Chemical powers. 4/A, Medical powers or virtues. 5th, Vege- table and animal powers. [249] That we perceive certain disorders in our own bodies by means of uneasy sensations, which nature hath conjoined with them, will not be disputed. Of this kind are toothache, headache, gout, and every distemper and hurt which we feel. The notions which our sense gives of these, have a strong analogy to our notions of secondary qualities. Both are similarly compounded, and may be similarly resolved, and they give light to each other. In the toothache, for instance, there is, first,, a painful feeling ; and, secondly, a conception and belief of some disorder in the tooth, which is believed to be the cause of the uneasy feeling. " The first of these is a sensation, the second is perception ; for it includes a conception and belief of an external object. But these two things, though of different natures, are so con- stantly conjoined in our experience and in our imagination, that we consider them as one. We give the same name to both ; for the toothache is the proper name of the pain we feel ; and it is the proper name of the disorder in the tooth which causes that pain. _ If it should be made a question whether the toothache be in the mind that feels it, or in the tooth that is affected, much might be said on both sides, while it is not observed that the word has two mean- ings, -f But a little reflection satisfies us, that the pain is in the mind, and the dis- order in the tooth. If some philosopher should pretend to have made the discovery that the toothache, the gout, the headache, are only sensations in the mind, and that it is a vulgar error to conceive that they are distempers of the body, he might defend his system in the same maimer as those who affirm that there is no sound, nor colour, nor taste in bodies, defend that para- dox. But both these systems, like most * There is no such perception, properly so called, The cognition is merely an inference from the feeling ; and its object, at least, only some hypothe- tical representation of a really ianotum quid. Here the subjective element preponderates so greatly as almost to extinguish the objective — I !. t This is not correct. See above, p. 205, col. b note *, and tJote D.— H. paradoxes, will be found to be only an abus '. of words. We say that we feel the toothache, not that we perceive it. On the other hand, we say that we perceive the colour of a body, not that we feel it. Can any reason be given for this difference of phraseology ? [250] In answer to this question, I apprehend that, both when we feel the toothache and when we see a coloured body, there is sensa- tion and perception conjoined. But, in the toothache, the sensation being very painful, engrosses the attention ; and therefore we speak of it as if it were felt only, and not perceived : whereas, in seeing a coloured body, the sensation is indifferent, and draws no attention. The quality in the body, which we call its colour, is the only object of attention ; and therefore we speak of it as if it were perceived and not felt. Though all philosophers agree that, in seeing colour there is sensation, it is not easy to persuade the vulgar that, in seeing a coloured body, when the light is not too strong nor the eye inflamed, they have any sensation or feeling at all. There are some sensations, which, though they are very often felt, are never attended to, nor reflected upon. We have no con- ception of them ; and, therefore, in language there is neither any name for them, nor any form of speech that supposes their existence. Such are the sensations of colour, and of all primary qualities ; and, therefore, those qualities are said to be perceived, but not to be felt. Taste and smell, and heat and cold, have sensations that are often agreeable or disagreeable, in such a degree as to draw our attention ; and they are sometimes said to be felt, and sometimes to be perceived. When disorders of the body occasion very acute pain, the uneasy sensa- ation engrosses the attention, and they are said to be felt, not to be perceived.* There is another question relating to phraseology, which this subject suggests. A man says, he feels pain in such a parti- cular part of his body ; in his toe for in- stance. Now, reason assures us that pain being a sensation, can only be in the sen- tient being, as its subject — that is, in the mind. And, though philosophers have dis- puted much about the place of the mind ; yet none of them ever placed it in the toe.-f- * As already repeatedly observed, the objective element (perception) and the subjective element (feeling, sensation) are always in the inverse ratio of each other. This is a law of which Reid and the philosophers were not aware — H. f Not in the xaeexclusively. But, both in ancient and modern times, the opinion has been held that the mind has as much a local presence in the toe as in the head. '1 he doctrine, indeed, long generally main- tained was, that in relation tothe horty, thesoulis all in the whole, and all in every pari. On the question of the seat of the soul, which has been marvellously perplexed, I c.inuot enter. I shall only say, in gene. ral, iha' the first condition of the possibility of ac [249, S30~] 320 ON THE INTELLECTUAL POWERS. Qessay n, What shall we say then in this case ? Do our senses really deceive us, and make us believe a thing which our reason determines to be impossible ? [251] I answer, first. That, when a man says he has pain in his toe, he is perfectly understood, both by himself and those who hear him. This is all that he intends. He really feels what he and all men call a pain in the toe ; and there is no deception in the matter. Whether, therefore, there be any impropriety in the phrase or not, is of no consequence in com- mon life. It answers all the ends of speech, both to the speaker and the hearers. In all languages there are phrases which have a distinct meaning; while, at the 6ame time, there may be something in the structure of them that disagrees with the analogy of grammar or with the principles of philosophy. And the reason is, because language is not made either by gramma- rians or philosophers. Thus, we speak of feeling pain, as if pain was something dis- tinct from the feeling of it. We speak of pain coming and going, and removing from one place to another. Such phrases are meant by those who use them in a sense that is neither obscure nor false. But the philosopher puts them into his alembic, reduces them to their first principles, draws out of them a sense that was never meant, and so imagines that he has discovered an error of the vulgar. I observe, secondly, That, when we con- sider the sensation of pain by itself, with- out any respect to its cause, we cannot say with propriety, that the toe is either the place or the subject of it. But it ought to be remembered, that, when we speak of pain in the toe, the sensation is combined in our thought, with the cause of it, which really is in the toe. The cause and the etfect are combined in one complex notion, and the same name serves for both. It is the busi- ness of the philosopher to analyse this com- plex notion, and to give different names to its different ingredients. He gives the name of pain to the sensation only, and the name of disorder to the unknown cause of it. Then it is evident that the disorder only is in the toe, and that it would be an error to think that the pain is in it. * But we ought not to ascribe this error to the vulgar, who never made the distinction, and who, under the name of pain, comprehend both the sensation and its cause. -f* [252] immediate, intuitive, or real perception of external things, which our consciousness assures that we pos- sess, is the immediate connection ofthe cognitive principle with every part of the corporeal organism. — * Only if the toe he considered as a mere material mass, and apart from an animating principle. — H. f That the pain is where it is felt is, however, the doctrine ot common sense. We only feel in as much ■*s we have a body and a anul ; we only fpel pain in the toe in as much as we have such a member, and in Cases sometimes happen, which give occasion even to the vulgar to distinguish the painful sensation from the disorder which is the cause of it. A man who has had liis leg cut off, many years after feels pain in a toe of that leg. The toe has now no existence ; and he perceives easily, that the toe can neither be the place nor the subject of the pain which he feels ; yet it is the same feeling he used to have from a hurt in the toe ; and, if he did not know that his leg was cut oft', it would give him the same immediate conviction of some hurt or dis- order iu the toe. * The same phenomenon may lead the philosopher, in all cases, to distinguish sens- ation from perception. We say, that the man had a deceitful feeling, when he felt a pain in his toe after the leg was cut off ; and we have a true meaning in saying so. But, if we will speak accurately, our sensa- tions cannot be deceitful ; they must be what we feel them to be, and can be no- thing else. Where, then, lies the deceit ? I answer, it lies not in the sensation, which is real, but in the seeming percepti n he had of a disorder in his toe. This percep- tion, which Nature had conjoined with the sensation, was, in this instance, fallacious. The same reasoning may be applied to every phenomenon that can, with propriety, be called a deception of sense. As when one who has the jaundice sees a body yellow, which is really white ;-f- or when a man sees an object double, because his eyes are not both directed to it : in these, and other like cases, the sensations we have are real, and the deception is only in the perception which nature has annexed to them. Nature has connected our perception of external objects with certain sensations. If the sensation is produced, the corre- sponding perception follows even when there is no object, and in that case is apt ta deceive us. [253] In like manner, nature has connected our sensations with certain impressions that are made upon the nerves and brain ; and, when the impression is made, from whatever cause, the corre- sponding sensation and perception imme- diately follow. Thus, in the man who feels pain in his toe after the leg is cut off, the nerve that went to the toe, part of which was cut off with the leg, had the same impres- sion made upon the remaining part, which, in the natural state of his body, was caused as much as the mind, or sentient principle, pervades it. We just as much feel in the toe as we think in in the head. If (but only if) the latter be a vitium subrcptionis, as Kant thinks, so is the former— H. * ihis illustration is Dcs Cartes*. If correct, it only shews that the connection of mind with organ, ization extends from the centre to the circumference of the nervous system, and is not limited to any p^rt.— H. ^ The man docs not a.-e the white body at all.— H. [251-253] chap. xvnt.J OP OTHER OBJECTS OF PERCEPTION. 321 by a hurt in the toe : and immediately this impression is followed by the sensation and perception which nature connected with it. " In like manner, if the same impressions which are made at present upon my optic nerves by the objects before me, could be made in the dark, I apprehend that I should have the same sensations and see the same objects which I now see. The im- pressions and sensations would in such a case be real, and the perception only fallacious.* Let us next consider the notions which our senses give us of those attributes of bodies called powers. This is the more necessary, because power seems to imply some activity ; yet we consider body as a dead inactive thing, which does not act, but may be acted upon. Of the mechanical powers ascribed to bodies, that which is called their vis insita or inertia, may first be considered. By this is meant, no more than that bodies never change their state of themselves, either from rest to motion, or from motion to rest, or from one degree of velocity or one direction to another. In order to produce any such change, there must be some force impressed upon them ; and the change produced is precisely proportioned to the force impressed, and in the direction of that force. That all bodies have this property, is a matter of fact, which we learn from daily observation, as well as from the most accu- rate experiments.. [254] Now, it seems plain, that this 1 does not imply any activity in body, but rather the contrary. A power in body to change its state, would much rather imply activity than its continuing in the same state : so that, although this property of bodies is called their vis insita, or vis inertia, it implies no proper activity. If we consider, next, the power of gravity, it is a fact that all the bodies of our pla- netary system gravitate towards each other. This has been fully proved by the. great Newton. But this gravitation is not con- ceived by that philosopher to be a power inherent in bodies, which they exert of themselves, but a force impressed upon them, to which they must necessarily yield. Whether this force be impressed by some subtile aether, or whether it be impressed by the power of the Supreme Being, or of some subordinate spiritual being, we do not know ; but all sound natural philosophy, particu- larly that of Newton, supposes it to be an impressed force, and not inherent in bodies. + So that, when bodies gravitate, they do * This is a doctrine which cannot be reconciled with that of an intuitive or objective perception. All here is subjective. — H. t That ail activity supposes an immaterial or spi- ritual agent, is an ancient doctrine. It is, however, only an hypothesis. — H. (254.-a5o'"l not properly act, but are acted upon : they only yield to an impression that is made upon them. It is common in language to express, by active verbs, many changes in things wherein they are merely passive : and this way of speaking is used chiefly when the cause of the change is not obvious to sense. Thus we say that a ship sails, when every man of common sense knows that she has no inherent power of motion, and is only driven by wind and tide. In like manner, when we say that the planets gravitate towards the sun, we mean no more but that, by some unknown power, they are drawn or impelled in that direction. What has been said of the power of gra- vitation may be applied to other mechanical powers, such as cohesion, magnetism, elec- tricity ; and no less to chemical and medical powers. By all these, certain effects are produced, upon the application of one body to another. [255] Our senses discover the effect; but the power is latent. We know there must be a cause of the effect, and we form a relative notion of it from its effect ; a n d very often the same name is used to signify the unknown cause, and the known effect. AVe ascribe to vegetables the powers of drawing nourishment, growing and multi- plying their kind. Here likewise the effect is manifest, but the cause is latent to sense. These powers, therefore, as well as all the other powers we ascribe to bodies, are un- known causes of certain known effects. It is the business of philosophy to investigate the nature of those powers as far as we are able ; but our senses leave us in the dark. We may observe a great similarity in the notions which our senses give us of second- ary qualities, of the disorders we feel in our own bodies, and of the various powers of bodies which we have enumerated. They are all obscure and relative notions, being a conception of some unknown cause of a known effect. Their names are, for the most part, common to the effect and to its cause ; and they are a proper subject of philosophical disquisition. They might, therefore, I think, not improperly be called occult qualities. This name, indeed, is fallen into disgrace since the time of Des Cartes. It is said to have been used by the Peripatetics to cloak their ignorance, and to stop all inquiry into the nature of those qualities called occvll. Be it so. Let those answer for this abuse of the word who were guilty of it. To call a thing occult, if we attend to the meaning of the word, is rather modestly to confers ignorance, than to cloak it. It is to point it out as a proper subject for the investiga- tion of philosophers, whose proper business it is to better the condition of humanity, by discovering what was before hid from human knowledge. [256] 322 ON THE INTELLECTUAL POWERS. Qessay 11. Were I therefore to make a division of the qualities of bodies as they appear to our senses, I would divide them first into those that are manifest and those that are occvl . The manifest qualities are those which Mr Locke calls primary ; such as Extension, Figure, Divisibility, Motion, Hardness, Softness, Fluidity. The nature of these is manifest even to sense ; and the business of the philosopher with regard to them, is not to find out their nature, which is wellknown, but to discover the effects produced by their various combinations ; and, with regard to those of them which are not essential to matter, to discover their causes as far as he is able. The second class consists of occult quali- ties, which may be subdivided into various kinds : as, first, the secondary qualities ; secondly, the disorders we feel in our own bodies ; and, thirdly, all the qualities which we call powers of bodies, whether mechani- cal, chemical, medical, animal, or vegetable; or if there be any other powers not compre- hended under these heads. Of all these the existence is manifest to sense, but the nature is occult ; and here the philosopher has an ample field. What is necessary for the conduct of our animal life, the bountiful Author of Nature hath made manifest to all men. But there are many other choice secrets of Nature, the discovery of which enlarges the power and exalts the state of man. These are left to be discovered by the proper use of our rational powers. They are hid, not that they may be always concealed from human knowledge, but that we may be excited to search for them. This is the proper busi- ness of a philosopher, and it is the glory of a man, and the best reward of his labour, to discover what Nature has thus con- cealed. [257] CHAPTER XIX. OP MATTER AND OF SPACE. The objects of sense we have hitherto considered are qualities. But qualities must have a subject. We give the names of matter, material substance, and body, to the subject of sensible qualities ; and it may be asked what this matter is. I perceive in a billiard ball, figure, colour, and motion ; but the ball is not figure, nor is it colour, nor motion, nor all these taken together; it is something that has figure, and colour, and motion. This is a dictate of nature, and the belief of all mankind. As to the nature of this something, I am afraid we can give little account of it, but that it hns the qualities which our senses discover. But how do we know that they are qua- lities, and cannot exist without a subject ? I confess I cannot explain how we know that they cannot exist without a subject, any more than I can explain how we know that they exist. We have the information of nature for their existence ; and I think we have the information of nature that they are qualities. The belief that figure, motion, and colour are qualities, and require a subject, must either be a judgment of nature, or it must be discovered by reason, or it must be a prejudice that has no just foundation. There are philosophers who maintain that it is a mere prejudice ; that a body is nothing but a collection of what we call sensible quali- ties ; and that they neither have nor need any subject. This is the opinion of Bishop Berkeley and Mr Hume; and they were led to it by finding that they had not in their minds any idea of substance. [258] It could neither be an idea of sensation nor of reflection. But to me nothing seems more absurd than that there should be extension without anything extended, or motion without any- thing moved ; yet I cannot give reasons for my opinion, because it seems to me self- evident, and an immediate dictate of my nature. And that it is the belief of all mankind, appears in the structure of all languages ; in which we find adjective nouns used to express sensible qualities. It is well known that every adjective in language must belong to some substantive expressed or undei- stood — that is, every quality must belong to some subject. Sensible qualities make so great a part of the furniture of our minds, their kinds are so many, and their number so great, that, if prejudice, and not nature, teach us to ascribe them all to a subject, it must have a great work to perform, which cannot be accomplished in a short time, nor carried on to the same pitch in every individual. We should find not individuals only, but nations and ages, differing from each other in the progress which this prejudice had made in their sentiments ; but we fiud no such difference among men. What one mau accounts a quality, all men do, and ever did. It seems, therefore, to be a judgment of nature, that the things immediately per- ceived are qualities, which must belong to a subject ; and all the information that our senses give us about this subject, is, that it is that to which such qualities belong. From this it is evident, that our notion of body or matter, as distinguished from its qualities, is a relative notion;* and I am ♦ That is— our notion of absolute body is retail* Tins is nicon ecily expressed. We can know, we can [257, aSbl CHAP XIX. ] OF MATTER AND OF SPACE. 323 afraid it must always be obscure until men have other faculties. [259] The philosopher, in this, seems to have no advantage above the vulgar; for, as they perceive colour, and figure, and motion by their senses as well he does, and both are equally certain that there is a subject of those qualities, so the notions which both have of this subject are equally ob- scure. When the philosopher calls it a substratum, and a subject of inhesion, those learned words convey no meaning but what every man understands and expresses, by saying, in common language, that it is a thing extended, and solid, and movable. The relation which sensible qualities bear to their subject — that is, to body — is not, however, so dark but that it is easily dis- tinguished from all other relations. Every man can distinguish it from the relation of an effect to its cause ; of a mean to its end ; or of a sign to the thing signified by it. I think it requires some ripeness of un- derstanding to distinguish the qualities of a body from the body. Perhaps this dis- tinction is not made by brutes, nor by in- fants ; and if any one thinks that this dis- tinction is not made by our senses, but by some other power of the mind, I will not dispute this point, provided it be granted that men, when their faculties are ripe, have a natural conviction that sensible qua- lities cannot exist by themselves without some subject to which they belong. I think, indeed, that some of the determ- inations we form concerning matter can- not be deduced solely from the testimony of sense, but must be referred to some other source. There seems to be nothing more evident than that all bodies must consist of parts ; and that every part of a body is a body, and a distinct being, which may exist without the other parts ; and yet I apprehend this con- clusion is not deduced solely from the testi- mony of sense : for, besides that it is a necessary truth, and, therefore, no object of sense,* there is a limit beyond which we conceive, only what is relative. Our knowledge of qualities or phenomena is necessarily relative ; for these exist only as they exist inrelation to our facul- ties. The knowledge, or even the conception, of a substance in itself, and apart from any qualities in relation to, and therefore cognisable or conceivable by, our minds, involves a contradiction. Of such we can form only a negative notion ; that is, we can merely conceive it as inconceivable. But to call this ne- gative notion a relative notion, is wrong ; 1°, because all our (positive) notions are relative -, and entative entities distinct from the knowing mind. [267 2691 miap xx. J OF THE EVIDENCE OF SENSE, &c. 327 1 beyond the power of human imagination to form any conception, whose simple ingre- dients have not been furnished by nature in a manner unaccountable to our understanding. We have an immediate conception of the operations of our own minds, joined with a a belief of their existence ; and this we call consciousness.* But this is only giving a name to this source of our knowledge. It is not a discovery of its cause. In like man- ner, we have, by our external senses, a I conception of external objects, joined with a belief of their existence ; and this we call perception. But this is only giving a name to another source of our knowledge, without discovering its cause. We know that, when certain impressions are made upon our organs, nerves, and brain, certain corresponding sensations are felt, and certain objects are both conceived and believed to exist. But in this train of operations nature works in the dark. We can neither discover the cause of any one of them, nor any necessary connection of one with another ; and, whether they are connected by any necessary tie, or only conjoined in our constitution by the will of heaven, we know not.-f That any kind of impression upon a body should be the efficient cause of sensation, ap- pears very absurd. Nor can we perceive any necessary connection between sensation and the conception and belief of an external object. For anything we can discover, we might have been so framed as to have all the sensations we now have by our senses, without any impressions upon our organs, and without any conception of any external object. For anything we know, we might have been so made as to perceive external objects, without any impressions on bodily organs, and without any of those sensa- tions which invariably accompany percep- tion in our present frame. [270] If our conception of external objects be unaccountable, the conviction and belief of their existence, which we get by our senses, is no less so.± * Here consciousness is made to consist in concep- tion. Hut, as Reid could hardly mean that con. sciousness conceives (i.e., represents) the operations about which it is conversant, and is not intuitively cognisant of them, it would seem that he occarionally employs conception lor knowledge. This is of im- portance in explaining favourubly Heiri's use of the word Conception in relation to Perception. But then, how vague and vacillating is his language I— H. t See p. -ibl, col. b, note *.— H. % If an immediate knowlf due of external things — that is, a consciousness of the qualities of the non- ccio — be admitted, the belief of their existence follows of course. On this supposition, therefore, such a belief would not be unaccountable j for it would be accounted for by the fact of the knowledge in which it would necessarily be contained. Our belief, in this case, of the existence of external objects, would not Demore inexplicable than our belief that 2 + S = *. In both cases it would be sufficient to say, we believe because tve know; for belief is only unaccountable when it is not the consequent or concomitant of [270-271] Belief, assent, conviction, are words which I do not think admit of logical defin- ition, because the operation of mind sig- nified by them is perfectly simple, and of its own kind. Nor do they need to be de- fined, because they are common words, and well understood. Belief must have an object. For he that believes must believe something ; and that which he believes, is called the object of his belief. Of this object of his belief, he must have some conception, clear or ob- scure ; for, although there may be the most clear and distinct conception of an object without any belief of its existence, there can be no belief without conception.* Belief is always expressed in language by a proposition, wherein something is affirmed or denied. This is the form of speech which in all languages is appropriated to that purpose, and without belief there could be neither affirmation nor denial, nor should we have any form of words to express either. Belief admits of all degrees, from the slightest suspicion to the fullest assur- ance. These things are so evident to every man that reflects, that it would be abusing the reader's patience to dwell upon them. I proceed to observe that there are many operations of mind in which, when we analyse them as far as we are able, we find belief to be an essential ingredient. A man cannot be conscious of his own thoughts, without believing that he thinks. He can- not perceive an object of sense, without be- lieving that it exists. -f- He cannot distinctly remember a past event, without believing that it did exist. Belief therefore is an ingredient in consciousness, in perception, and in remembrance. [271] Not only inmost of our intellectual oper- ations, but in many of the active princi- ples of the human mind, belief enters as an ingredient. Joy and sorrow, hope and fear, imply a belief of good or ill, either pre sent or in expectation Esteem, gratitude, pity, and resentment, imply a belief of cer- tain qualities in their objects. In every action that is done for an end, there must be a belief of its tendency to that end. So large a share has belief in our intellectual knowledge. By this, however, I do not, of course, mean to say that knowledge is not in itself marvel- lous and unaccountable. This statement of Keid again lavours the opinion that his doctrine of percep- tion is not really immediate..— H. * Is conception here equivalent to knowledge or to thought f— a. f Mr Stewart (Elem. I., ch. iii., p. 146, and Essays, II., ch. ii., p. 79, sq.) proposes a supplement to this doctrine of Heid, in order to explain why we believe in the existence of the qualities of external objects when they are not the objects of our perception. This belief he holds to be the result of experience, in combination with an original principle ol our consti- tution, whereby we are detirmined to believe in the permanence of the laws of nature.— H 328 ON THE INTELLECTUAL POWERS. [essay It. operations, in our active principles, and in our actions themselves, that, as faith in tilings divine is represented as the main spring in the life of a Christian, so belief in general is the main spring in the life of a man. That men often believe what there is no just ground to believe, and thereby are led into hurtful errors, is too evident to be denied. And, on the other hand, that there are just grounds of belief can as little be doubted by any man who is not a, perfect sceptic. We give the name of evidence to what- ever is a ground of belief. To believe with- out evidence is a weakness which every man is concerned to avoid, and which every man wishes to avoid. Nor is it in a mau's power to believe anything longer than he thinks he has evidence. What this evidence is, is more easily felt than described. Those who never reflected upon its nature, feel its influence in govern- ing their belief. It is the business of the logician to explain its nature, and to dis- tinguish its various kinds and degrees ; but every man of understanding can judge of it, and commonly judges right, when the evi- dence is fairly laid before him, and his mind is free from prejudice. A man who knows nothing of the theory of vision may have a good eye; and a man who never speculated about evidence in the abstract may have a good judgment. [272] The common occasions of life lead us to distinguish evidence into different kinds, to which we give names that are well under- stood ; such as the evidence of sense, the evidence of memory, the evidence of con- sciousness, the evidence of testimony, the evidence of axioms, the evidence of reason- ing. All men of common understanding agree that each of these kinds of evidence may afford just ground of belief, and they agree very generally in the circumstances that strengthen or weaken them. Philosophers have endeavoured, by ana- lysing the different sorts of evidence, to lind out some common nature wherein they all agree, and thereby to reduce them all to one. This was the aim of the school- men in their intricate disputes about the criterion of truth. Des Cartes placed this criterion of truth in clear and distinct per- ception, and laid it down as a maxim, that whatever we clearly and distinctly perceive to be true, is true ; but it is difficult to know what he understands by clear and distinct perception in this maxim. Mr Locke placed it in a perception of the agree- ment or disagreement of our ideas, which perception is immediate in intuitive know- ledge, and by the intervention of other ideas in reasoning. I confess that, although I have, as I think, a distinct notion of the different kinds of evidence above-mentioned, and, perhaps, of some others, which it is unne- cessary here to enumerate, yet I am not able to find any common nature to which they may all be reduced. They seem to me to agree only in this, thai they are all fitted by Nature to produce belief in the human mind, some of them in the highest degree, which we call certainty, others in various degrees according to circumstances. I shall take it for granted that the evi- dence of sense, when the proper circum- stances concur, is good evidence, and a just ground of belief. My intention in this place is only to compare it with the other kinds that have been mentioned, that we may judge whether it be reducible to any of them, or of a nature peculiar to itself. [273] First, It seems to be quite different from the evidence of reasoning. All good evi- dence is commonly called reasonable evi- dence, and very justly, because it ought to govern our belief as reasonable creatures. And, according to this meaning, I think the evidence of sense no less reasonable than- that of demonstration.* If Nature give us information of things that concern us, by other means than by reasoning, reason itself will direct us to receive that inform- ation with thankfulness, and to make the best use of it. But, when we speak of the evidence of reasoning as a particular kind of evidence, it means the evidence of propositions that are inferred by reasoning, from propositions already known and believed. Thus, the evidence of the fifth proposition of the first book of Euclid's Elements consists in this, That it is shewn to be the necessary consequence of the axioms, and of the pre- ceding propositions. In all reasoning, there must be one or more premises, and a con- clusion drawn from them. And the pre- mises are called the reason why we must believe the conclusion which we see to fol- low from them. That the evidence of sense is of a differ- ent kind, needs little proof. No man seeks a reason for believing what he sees or feels ; and, if he did, it would be difficult to find one. But, though he can give no reason for believing his senses, his belief remains as firm as if it were grounded on demon- stration. Many eminent philosophers, thinking it unreasonable to believe when they could not shew a reason, have laboured to furnish us with reasons for believing our senses ; but their reasons are very insufficient, and will not bear examination. Other philoso- * Zviniv XSynv uniiTots TY,t «.lfBriirir. x^ptusi'a Tie Ul timtixf — Ay totle. Uimrixt,, „i W t«»™ 701s S.« yiv AayMS «AA« -rokXixl; /J.S.KU, roTr f.m/iiio!.- [. ' TJ*urHtra /AaXXoir r, ™ Xoyoi vls-turior xtti rots loyois- tC6Votfoloyvjfi.HK Utxtuaxri , for that which if perceived— the idea in their doctrine j and 3°, for either or both indifferently H. .J See above p. 222, b, note * j p. 280, a. note*.— H. ^ The term object being then . used tor the imme- diate object— viz., that of which we are conscious. — H standing his 'great judgment and candour, his understanding was entangled by the ambiguity of the word idea, and that most of the imperfections of his Essay are owing to that cause. Mr Hume saw farther into the conse- quences of the common system concerning ideas than any author had done before him. He saw the absurdity of making every obj ect of thought double, and splitting it into a remote object, which has a separate and permanent existence, and an immediate - object, called an idea or impression, which is an image of the former, and has no ex- istence, but when we are conscious of it. According to this system, we have no in- tercourse with the external world, but by means of the internal world of ideas, which represents the other to the mind. He saw it was necessary to reject one of these worlds as a fiction, and the question was, Which should be rejected? — whether all mankind, learned and unlearned, had feigned the existence of the external world without good reason ; or whether philoso- phers had feigned the internal world of ideas, in order to account for the intercourse of the mind with the external ? [347] Mr Hume adopted the first of these opinions, and employed his reason and eloquence in support of it. Bishop Berkeley had gone so far in the same track as to reject the material world as fictitious ; but it was left to Mr Hume to complete the system. According to his system, therefore, im- pressions and ideas in his own mind are the only things a man can know or can conceive. Nor are these ideas representa- tives, as they were in the old system. There is nothing else in nature, or, at least, within the reach of our faculties, to be re- presented. What the vulgar call the per- ception of an external object, is nothing but a strong impression upon the mind. What we call the remembrance of a past event, is nothing but a present impression or idea, weaker than the former. And what we call imagination, is still a present idea, but weaker than that of memory. That I may not do him injustice, these are his words in his " Treatise of Human Nature," [vol. I.] page 193. - " We find by experience that, when any impression has been present with the mind, it again makes its appearance there as an idea ; and this it may do after two different ways, either when in its new appearance it retains a considerable degree of its first vivacity and is somewhat intermediate be- twixt an impression and anjdea, or when it entirely loses that vivacity, and is a perfect idea. The faculty by which we repeat our impressions in the first manner, is called the memory, and the other the imagination." [316. 347 CHAP. VII. THEORIES CONCERNING MEMORY. 357 Upon this account of memory and imagi- nation, I shall make some remarks. [348] First, I wish to know what we are here to understand by experience ? It is said, we find all this by experience ; and I con- ceive nothing can be meant by this expe- rience but memory — not that memory which our author defines, but memory in the common acceptation of the word. Ac- cording to vulgar apprehension, memory is an immediate knowledge of something past. Our author does not admit that there is any such knowledge in the human mind. He maintains that memory is nothing but a present idea or impression. But, in de- fining what he takes memory to be, he takes for granted that kind of memory which he rejects. For, can we find by experience, that an impression, after its first appearance to the mind, makes a second and a third, with different degrees of strength and vivacity, if we have not so distinct a remembrance of its first appearance as enables us to know it upon its second and third, notwithstand- ing that, in the interval, it has undergone a very considerable change ?* All experience supposes memory; and there can be no such thing as experience, without trusting to our own memory, or that of others. So that it appears, from Mr Hume's account of this matter, that he found himself to have that kind of memory which he acknowledges and defines, by ex- ercising that kind which he rejects. Secondly, What is it we find by expe- rience or memory ? It is, " That, when an impression has been present with the mind, it again makes its appearance there as an idea, and that after two different ways." If experience informs us of this, it cer- tainly deceives us ; for the thing is impos- sible, and the author shews it to be so. Impressions and ideas are fleeting, perish- able things, which have no existence but when we are conscious of them. If an im- pression could make a second and a third appearance to the mind, it must have a continued existence during the interval of these appearances, which Mr Hume ac- knowledges to be a gross absurdity. [349] It seems, then, that we find, by experience, a thing which is impossible. We are im- posed upon by our experience, and made to believe contradictions. Perhaps it may be said, that these dif- ferent appearances of the impression are not to be understood literally, but figuratively ; that the impression is personified, and made to appear at different times and in different habits, when no more is meant but that an impression appears at one time ; afterwards a thing of a middle nature, between an im- pression and an idea, which we call memory ; [34.8-350"] * See Note B H. and, last of all, a perfect idea, which we call imagination : that this figurative meaning agrees best with the last sentence of the period, where we are told that memory and imagination are faculties, whereby we repeat our impresions in a more or less lively manner. To repeat an impression is a figur- ative way of speaking, which signifies making a new impression similar to the former. If, to avoid the absurdity implied in the literal meaning, we understand the philo- sopher in this figurative one, then his defini- tions of memory and imagination, when stripped of the figurative dress, will amount to this, That memory is the faculty of making a weak impression, and imagination the faculty of making an impression still weaker, after a corresponding strong one. These definitions of memory and imagina- tion labour under two defects : First, That they convey no notion of the thing defined ; and, Secondly, That they may be applied to things of a quite different nature from those that are defined. When we are said to have a faculty of making a weak impression after a corre- sponding strong one, it would not be easy to conjecture that this faculty is memory. Suppose a man strikes his head smartly against the wall, this is an impression ; now, he has a faculty by which he can repeat this impression with less force, so as not to hurt him : this, by Mr Hume's account, must be memory. [350] He has a faculty by which he can just touch the wall with his head, so that the impres- sion entirely loses its vivacity. This surely must be imagination ; at least, it comes as near to the definition given of it by Mr Hume as anything I can conceive. Thirdly, We may observe, that, when we are told that we have a faculty of repeating our impressions in a more or less lively manner, this implies that we are the effi- cient causes of our ideas of memory and imagination ; but this contradicts what the author says a little before, where he proves, by what he calls a convincing argument, that impressions are the cause of their cor- responding ideas. The argument that proves this had need, indeed, to be very con- vincing ; whether we make the idea to be a second appearance of the impression, or a new impression simil ar to the formes. If the first be true, then the impression is the cause of itself. If the second, then the impression, after it is gone and has no existence, produces the idea. Such are the mysteries of Mr Hume's philosophy. It may be observed, that the common system, that ideas are the only immediate objects of thought, leads to scepticism with regard to memory, as well as with regard 1 to the objects of sense, whether those ideas are placed in the mind or in the brain. 358 ON THE INTELLECTUAL POWERS. Qessay 111 Ideas are said to be tilings internal and present, which have no existence but during the moment they are in the mind. The objects of sense are things external, which hare a continued existence. When it is maintained that all that we immediately perceive is only ideas or phantasms, how can we, from the existence of those phan- tasms, conclude the existence of an external world corresponding to them ? This difficult question seems not to have dccurred to the Peripatetics.* Des Cartes saw the difficulty, and endeavoured to find out arguments by which, from the existence of our phantasms or ideas, we might infer the existence of external objects. [351] The same course was followed by Malebranche, Arnauld, and Locke; but Berkeley and Hume easily refuted all their arguments, and demonstrated that there is no strength in them. The same difficulty with regard to mem- ory naturally arises from the system of ideas ; and the only reason why it was not observed by philosophers, is, because they give less attention to the memory than to the senses ; for, since ideas are things pre- sent, how can we, from our having a certain idea piesently in our mind, conclude that an event really happened ten or twenty years ago, corresponding to it ? There is the same need of arguments to prove, that the ideas of memory are pictures of things that really did happen, as that the ideas of sense are pictures of external objects which now exist. In both cases, it will be impossible to find any argument that has real weight. So that this hypothesis leads us to absolute scepticism, with regard to those things which we most distinctly re- member, no less than with regard to the external objects of sense. It does not appear to have occurred either to Locke or to Berkeley, that their system has the same tendency to overturn the tes- timony of memory as the testimony of the senses. Mr Hume saw farther than both, and found this consequence of the system of ideas perfectly corresponding to his aim of establishing universal scepticism. His sys- stem is therefore more consistent than theirs, and the conclusions agree better with the premises. But, if we should grant to Mr Hume that our ideas of memory afford no just ground to believe the past existence of things which we remember, it may still be asked, How it * This is not correct. See above, p. 2R5, note f. To that note I. may add, that no orViodox Catholic could be an Idealist. It was only the doctrine of transsubstantiation that prevented Malebranche from pre-occupying the theory of Berkeley and Collier, which was in fact his own, with the transcendent reality of a material world left out, as a Protestant hors d'atuvre. This, it is curious, has never been observed. See Note P.— H, comes to pass that perception and memory are accompanied with belief, while bare ima- gination is not ? Though this belief can- not be justified upon his system, it ought to be accounted for as a phenomenon of hu- man nature. [352] This he has done, by giving us a new theory of belief in general ; a theory which suits very well with that of ideas, and seems to be a natural consequence of it, and which, at the same time, reconciles all the belief that we find in human nature to perfect scepticism. What, then, is this belief? It must either be an idea, or some modification of an idea ; we conceive many things which we do not believe. The idea of an object is the same whether we believe it to exist, or barely conceive it. The belief adds no new idea to the conception ; it is, therefore, no- thing but a modification of the idea of the thing believed, or a different manner of conceiving it. Hear himself : — " All the perceptions of the mind are of two kinds, impressions and ideas, which differ from each other only in their different degrees of force and vivacity. Our ideas are copied from our impressions, and repre- sent them in all their parts. When you would vary the idea of a particular object, you can only increase or d iminis h its force and vivacity. If you make any other change upon it, it represents a different object or impression. The case is the same as in colours. A particular shade of any colour may acquire a new degree of liveliness or brightness, without any other variation ; but, when you produce any other variation, it is no longer the same shade or colour. So that, as belief does nothing but vary the manner in which we conceive any object, it can only bestow on our ideas an additional force and vivacity. An opinion, therefore, or belief, may be most accurately defined a lively idea, related to or associated with a present impressinn." This theory of belief is very fruitful of consequences, which Mr Hume traces with his usual acuteness, and brings into the service of his system. [353] A great part of his system, indeed, is built upon it ; and it is of itself sufficient to prove what he calls his hypothesis, " that belief is more properly an act of the sensitive than of the cogitative part of our natures." It is very difficult to examine this ac- count of belief with the same gravity with which it is proposed. It puts one in mind of the ingenious account given by Martinus Scriblerus of the power of syllo- gism, by making the major the male, and the minor the female, which, being couplea by the middle term, generate the conclusion. There is surely no science in which men ol great parts and ingenuity have fallen into T351-353] OHAP. VII.] THEORIES CONCEKNING MEMORY. 359 such gross absurdities as in treating of the powers of the mind. I cannot help think- ing that never anything more absurd was gravely _ maintained by any philosopher, than this account of the nature of belief, and of the distinction of perception, memory, and imagination. The belief of a proposition is an opera- tion of mind of which every man is con- scious, and what it is he understands per- fectly, though, on account of its simplicity, he cannot give a logical definition of it. If he compares it with strength or vivacity of his ideas, or with any modification of ideas, they are so far from appearing to be one and the same, that they have not the least similitude. That a strong belief and a weak belief differ only in degree, I can easily compre- hend ; but that belief and no belief should differ only in degree, no man can believe who understands what he speaks. For this is, in reality, to say that something and nothing differ only in degree ; or, that nothing is a degree of something. Every proposition that may be the ob- ject of belief, has a contrary proposition that may be the object of a contrary belief. The ideas of both, according to Mr Hume, are the same, and differ only in degrees of vivacity — that is, contraries differ only in degree ; and so pleasure may be a degree of pain, and hatred a degree of love. [354] But it is to no purpose to trace the absurd- ities that follow from this doctrine, for none of them can be more absurd than the doc- trine itself. Every man knows perfectly what it is to see an object with his eyes, what it is to remember a past event, and what it is to conceive a thing which has no existence. That these are quite different operations of his mind, he is as certain as that sound differs from colour, and both from taste ; and I can as easily believe that sound, and colour, and taste differ only in degree, as that seeing, and remembering, and imagin- ing, differ only in degree. Mr Hume, in the third volume of his " Treatise of Human Nature," is sensible that his theory pi belief is liable to strong objections, and seems, in some measure, to retract it ; but in what measure, it is not easy to say. He seems still to think that belief is only a modification of the idea ; but that vivacity is not a proper term to express that modification. Instead of it, he uses some analogical phrases, to explain that modification, such as " apprehending the idea more strongly, or taking faster hold of it." There is nothing more meritorious in a philosopher than to retract an error upon conviction ; but, in this instance, I hum- bly apprehend Mr Hume claims that merit [864-3561 upon too slight a ground. For I cannot perceive that the apprehending an idea more strongly, or taking faster hold of it, expresses any other modification of the idea than what was before expressed by its strength and vivacity, or even that it ex- presses the same modification more pro- perly. Whatever modification of the idea he makes belief to be, whether its vivacity, or some other without a name, to make perception, memory, and imagination to be the different degrees of that modification, is chargeable with the absurdities we have mentioned. Before we leave this subject of memory, it is proper to take notice of a distinction which Aristotle makes between memory and reminiscence, because the distinction has a real foundation in nature, though in our language, I think, we do not distinguish them by different names. [355] Memory is a kind of habit which is not always in exercise with regard to things we remember, but is ready to suggest them when there is occasion. The most perfect degree of this habit is, when the thing pre- sents itself to our remembrance spontane- ously, and without labour, as often as there is occasion. A second degree is, when the thing is forgot for a longer or shorter time, even when there is occasion to remember it ; yet, at last, some incident brings it to mind without any search. A third degree is, when we cast about and search for what we would remember, and so at last find it out. It is this last, I think, which Ari- stotle calls reminiscence, as distinguished from memory. Reminiscence, therefore, includes a will to recollect something past, and a search for it. But here a difficulty occurs. It may be said, that what we will to remember we must conceive, as there can be no will with- out a conception of the thing willed. A will to remember a thing, therefore, seems to imply that we remember it already, and have no occasion to search for it. But this difficulty is easily removed. When we wil! to remember a thing, we must remember something relating to it, which gives us. a relative conception of it ; but we may, at the same time, have no conception what the thing is, but only what relation it bears to something else. Thus, I remember that a friend charged me with a commission to lie executed at such a place ; but I have forgot what the commission was. By applying my thought to what I remember concerning it, that it was given by such a person, upon such an occasion, in consequence of such a conversation, I am led, in a train of thought, to the very thing I had forgot, and recol- lect distinctly what the commission was. [356] Aristotle says, that brutes have not re- 360 ON THE INTELLECTUAL POWERS. [essay iv miniscence ;* and this I think is probable ; but, says he, they have memory. It cannot, indeed, be doubted but they have something very like to it, and, in some instances, in a very great degree. A dog knows his master after long absence. A. horse will trace back a road he has once gone, as accurately as a man ; and this is the more strange, that the train of thought which he had in going must be reversed in his return. It is very like to some prodigious memories we read of, where a person, upon hearing an hundred names or unconnected words pronounced, can begin at the last, and go backwards to the first, without losing or misplacing one. Brutes certainly may learn much from ex- perience, which seems to imply memory. Yet, I see no reason to think that brutes measure time as men do, by days, months, or years ; or that they have any distinct knowledge of the interval between things which they remember, or of their distance from the present moment If we could not record transactions according to their dates, human memory would be something very different from what it is, and, perhaps, re- semble more the memory of brutes. [357] ESSAY IV. OF CONCEPTION. CHAPTER I. DP CONCEPTION, OR SIMPLE APPREHENSION IN GENERAL. Conceiving, imagining,-^ apprehending, un- derstanding, having a notion of a thing, are common words, used to express that opera- tion of the understanding which the logi- cians call simple apprehension. The having an idea of a thing, is, in common language, used in the same sense, chiefly, I think, since Mr Locke's time. J Logicians define Simple Apprehension to be the bare conception of a thing without any judgment or belief about it. If this were intended for a strictly logical definition, it might be a just objection to it, that con- ception and apprehension are only synony- mous words ; and that we may as well define conception by apprehension, as appre- hension by conception ; but it ought to be * This is a question which may be differently an- swered, according as we attribute a different meaning to the terms employed.— H. t Imagining should not be confounded with Con. ceiving, &c. ; though some philosophers, as Gassendi, have not attended to the distinction. The words Conception, Concept, Jiotion, should be limited to the thought of what cannot be represented in the imagin- ation, as the thought .suggested by a general term. The Leibnitians call this symbolical in contrast' to intuitive knowledge. This- is the sense 'in which conceptio&ria conceptus have been usually and cor- rectly employed. Mr Stewart, on the other band, arbitrarily limits Conception to the reproduction, in imagination, of an object of sense as actually per- ceived. See Elements, vol. L, ch. iii. I cannot enter on a general criticism of Reid's nomenclature, though I may say something more of this In the sequel. See below, under pp. 371, 483.— H. X In this country should be added. Locke only introduced into English philosophy the term idea in ils Cartesian universality. Prior to him, the word was only used with us in its Platonic signification. Before Des Cartes, David Buchanan, a Scotch philo- sopher, who sojourned in France, had, however, em- ployed Idea in an. equal latitude. See Note G.- H. remembered that the most simple operations of the mind cannot be logically defined. To have a distinct notion of them, we must attend to them as we feel them in our own minds. He that would have a distinct notion of a scarlet colour, will never attain it by a definition ; he must set it before bis eye, attend to it, compare it with the colours that come nearest to it, and observe the specific difference, which he will in vain attempt to define.* [358] Every man is conscious that he can con- ceive a thousand things, of which he believes nothing at all — as a horse with wings, a mountain of gold ; but, although concep- tion may be without any degree of belief, even the smallest belief cannot be without conception. He that believes must have some conception of what he believes. Without attempting a definition of this operation of the mind, I shall endeavour to explain some of its properties ; consider the theories about it ; and take notice of some mistakes of philosophers concerning it. 1. It may be observed that conception enters as an ingredient in every operation of the mind. Our senses cannot give us the belief of any object, without giving some conception of it at the same time. No man can either remember or reason about things of which he hath no conception. When we will to exert any of our active powers, there must be some conception of what we will to do. There can be no desire nor aversion, love nor hatred, without some con- ception of the object. We cannot feel pain without conceiving it, though we can con- ceive it without feeling it. These things are self-evident. In every operation of the mind, there- * We do not define the specific difference, but w» define by it,— H. [357, 368] uhap. i.] OF SIMPLE APPREHENSION IN GENERAL. 361 fore, in everything we call thought, there must be conception. When we analyse the various operations either of the understand- ing or of the will, we shall always find this at the bottom, like the caput mortuum of the chemists, or the materia prima of the Peripatetics ; hut, though there is no opera- tion of mind without conception, yet it may be found naked, detached from all others, and then it is called simple apprehension, or the bare conception of a thing. As all the operations of our mind are ex- pressed by language, every one knows that it is one thing to understand what is said, to conceive or apprehend its meaning, whether it be a word, a sentence, or a dis- course ; it is another thing to judge of it, to assent or dissent, to be persuaded or moved. The first is simple apprehension, and may be without the last ; but the last cannot be without the first. „ [359] 2. In bare conception there can neither be truth nor falsehood, because it neither affirms nor denies. Every judgment, and every proposition by which judgment is expressed, must be true or false ; and the qualities of true and false, in their proper sense, can belong to nothing but to judg- ments, or to* propositions which express judgment. In the bare conception of a thing there is no judgment, opinion, or be- lief included, and therefore it cannot be either true or false. But it may be said, Is there anything more certain than that men may have true or false conceptions, true or false appre- hensions, of things ? I answer, that such ways of speaking are indeed so common, and so well authorized by custom, the arbiter of language, that it would be presumption to censure them. It is hardly possible to avoid using them. But we ought to be upon our guard that we be not misled by them, to confound things which, though often expressed by the same words, are really different. We must therefore re- member what was before observed, Essay I. ' chap. I — that all the words by which we signify the bare conception of a thing, are likewise used to signify our opinions, when we wish to express them with modesty and diffidence. And we shall always find, that, when we speak of true or false' conceptions, we mean true or false opinions. An opinion, though ever so wavering, or ever so mo- destly expressed, must be either true or false ; but a bare conception, which ex- presses no opinion or judgment, can be neither. If we analyse those speeches in which men attribute truth or falsehood to our conceptions of things, we shall find in every case, that there is some opinion or judgment implied in what they call conception. [360] A child conceives the moon to be flat, and a [359-861] foot or two broad — that is, this is his opinion : and, when we say it is a false notion or a false conception, we mean that it is a false opinion. He conceives the city of London to be like his country village — that is, he believes it to be so, till he is better instructed. He conceives a lion to have horns ; that is, he believes that the animal which men call a lion, has horns. Such opinions language authorizes us to call conceptions ; and they may be true or false. But bare conception, or what the logicians call simple apprehen- sion, implies no opinion, however slight, and therefore can neither be true nor false. What Mr Locke says of ideas (by which word he very often means nothing but con- ceptions) is very just, when the word idea is so understood. Book II., chap, xxxii., § L " Though truth and falsehood belong in propriety of speech only to propositions, yet ideas are often termed true or false (as what words are there that are not used with great latitude, and with some deviation from their strict and proper signification ?) though I think that when ideas themselves are termed true or false, there is still some secret or tacit proposition, which is the foundation of that denomination : as we shall see, if we examine the particular occasions wherein they come to be called true or false ; in all which we shall find some kind of affirmation or negation, which is the reason of that denomination ; for our ideas, being nothing but bare appearances, or perceptions in our minds, cannot properly and simply in themselves be said to be true or false, no more than a simple name of anything can be said to be true or false." It may be here observed, by the way, that, in this passage, as in many others, Mr Locke uses the word perception, as well as the word idea, to signify what I call con- ception, or simple apprehension. And in his chapter upon perception, Book II., chap. ix., he uses it in the same sense. Percep- tion, he says, " as it is the first faculty of the mind, exercised about our ideas, so it is the first and simplest idea we have from reflection, and is by some called thinking in general. [361] It seems to be that which puts the distinction betwixt the ani- mal kingdom and the inferior parts of nature. It is the first operation of all our faculties, and the inlet of all knowledge into our minds." Mr Locke has followed the example given by Des Cartes, Gassendi, and other Carte- sians,* in giving the name of perception to the bare conception of things : and he has been followed in this by Bishop Berkeley, * Gassendrvvas not a Cartesian, but an Anti-Car tesian, though he adopted several points in his phi. losoohy from Des Cartes — for example, the employ- ment of the term Idea not in its Platonic limitation — B. 362 ON THE INTELLECTUAL POWERS. Qf.ssay IV. Mr Hume, and many late philosophers, when they treat of ideas. They have pro- bably been led into this impropriety, by the common doctrine concerning- ideas, which teaches us, that conception, perception by the senses, and memory, are only different ways of perceiving ideas in our own minds. " If that theory be well founded, it will in- deed be very difficult to find any specific distinction between conception ;and percep- tion, -f But there is reason to distrust any philosophical theory when it leads men to corrupt language, and to confound, under one name, operations of the mind which common sense and common language teach them to distinguish. I grant that there are some states of the mind, wherein a man may confound his conceptions with what he perceives or re- members, and mistake the one for the other ; as in the delirium of a fever, in some cases of lunacy and of madness, in dreaming, and perhaps in some momentary transports of devotion, or of other strong emotions, which cloud his intellectual faculties, and, for a time, carry a man out of himself, as we usually express it. Even in a sober and sound state of mind, the memory of a thing may be so very weak that we may be in doubt whether we only dreamed or imagined it. It may be doubted whether children, when their imagination first begins to work, can distinguish what they barely conceive from what they remember. [362] I have been told, by a man "of knowledge and ob- servation, that one of his sons, when he began to speak, very often told lies with great assurance, without any intention, as far as appeared, or any consciousness of guilt. From which the father concluded, that it is natural to some . children to lie- I am rather inclined to think that the child had no intention to deceive, but mistook the rovings of his own fancyfor things which he remembered. J This, however, I take to be very uncommon, after children can communicate their sentiments by language, though perhaps not so in a more early period. Granting all this, if any man will affirm that they whose intellectual faculties are sound, and sober, and ripe, cannol with certainty distinguish what they perceive or remember, from what they barely conceive, when those operations have any degree of strength and distinctness, he may enjoy his * But see-above, p. 280, a, note* etalibL—H. [ Yet Reid himself defines Perception, a Concep- tion (imagination) accompanied with a belief in the existence of its object; and Mr Stewart reduces the specific difference, at best only a concomitant, to an accidental circumstance, in holding that our im- aginations are themselves conjoined with a tempo- rary belief in their objective reality.— H. t But compare above, p. 340, col. a H. opinion ; I know not how to reason with him. Why should philosophers confound those operations in treating of ideas, when they would be ashamed to do it on other occasions? To distinguish the various powers of our minds, a certain degree of understanding is necessary. And if some, through a defect of Understanding, natural or accidental, or from unripeness of under- standing, may be apt to confound different powers, will it follow that others cannot clearly distinguish them ? To return from this digression — into which the abuse oPrhe word perception, by philo- sophers, has led me — it appears evident that the bare conception of an object, which includes no opinion or judgment, can neither be true nor false. Those qualities, in their proper sense, are altogether inapplicable to this operation of the mind. 3. Of all the analogies between the opera- tions of body and those of the mind, there is none so strong and so obvious to all man- kind as that which there is between paint- ing, or other plastic arts, and the power of conceiving objects in the mind. Hence, in all languages, the words by which this power of the mind and its various modifications are expressed, are analogical, and borrowed from those arts. [363] We consider this power of the mind as a plastic power, by which we form to ourselves images of the objects of thought. In vain should we attempt to avoid this analogical language, for we have no other language upon the subject ; yet it is danger- ous, and apt to mislead. All analogical and figurative words have a double meaning ; and, if we are not very much upon our guard, we slide insensibly from the bor- rowed and figurative meaning into the pri- mitive. We are prone to carry the parallel between the things compared farther than it will hold, and thus very naturally to fall into error. To avoid this as far as possible in the pre- sent subject, it is proper to attend to the dissimilitude between conceiving a thing in the mind, and painting it to the eye, as well as to their similitude. The similitude strikes and gives pleasure. The dissimilitude we are less disposed to observe ; but the philo- sopher ought to attend to it, and to carry it always in mind, in his reasonings on this subject, as a monitor, to warn him against the errors into which the analogical lan- guage is apt te draw him. When a man paints, there is some work done, which remains when his hand is taken off, and continues to exist though he should think no more of it. Every stroke of his pencil produces an effect, and this effect is different from his action in making it; for it remains and continues to exist when the action ceases. The action of painting is 1 362, ear chap. i. J OF SIMPLE APPREHENSION IN GENERAL. 363 one thing ; the picture produced is another thing. The first is the cause, the second is the effect. Let us next consider what is done when he only conceives this picture. He must have conceived it before he painted it ; for this is a maxim universally admitted, that every work of art must first be conceived in the mind of the operator. What is this conception ? It is an act of the mind, a kind of thought. This cannot be denied. [364] But does it produce any effect besides the act itself ? Surely common sense answers this question in the negative ; for every one knows that it is one thing to conceive, another thing to .bring forth into effect. It is one thing to project, another to execute. A man may think for a long time what he is to do, and after all do nothing. Con- ceiving, as well as projecting or resolving, are what the schoolmen called immanent acts of the mind, which produce nothing beyond themselves. But painting is a transitive act, which produces an effect distinct from the operation, and this effect is the picture. Let this, therefore, be always remembered, that what is commonly called the image of a thing in the mind, is no more than the act or operation of the mind in conceiving it. That this is the common sense of men who are untutored by philosophy, appears from their language. If one ignorant of the language should ask, What is meant by conceiving a thing ? we should very natur- ally answer, that it is having an image of it in the mind — and perhaps we could not explain the word better. This shews that conception, and the image of a thing in the mind, are synonymous expressions. The image in the mind, therefore, is not the object of conception, nor is it any effect produced by conception as a cause. It is conception itself. That very mode of think- ing which we call conception, is by another name called an image in the mind.* Nothing more readily gives the concep- tion of a thing than the seeing an image of it Hence, by a figure common in language, conception is called an image of the thing conceived. But to shew that it is not a real but a metaphorical image, it is called an image in the mind. We know nothing that is properly in the mind but thought ; and, when anything else is said to be in the mind, the expression must be figurative, and signify some kind of thought. [365] I know that philosophers very unani- mously maintain, that in conception there * We ought, however, to distinguish Imagination and Image, Conception and Concept. Imagination and Conception ought to be- employed in speaking of the mental modification, one 1 and indivisible, con- sidered as an act ; Image and Concept, in speaking of it, considered as a product or immediate object. — a rS64-366l is a real image in the mind, which is the immediate object of conception, and distinct from the act of conceiving it. I beg the reader's indulgence to defer what may be said for or against this philosophical opinion to the next chapter ; intending in this only to explain what appears to me to belong to this operation of mind, without considering the theories about it. I think it appears, from what has been said, that the common language of those who have not imbibed any philosophical opinion upon this subject, authorizes us to understand the conception of a thing, and an image of it in the mind, not as two different things, but as two dif- ferent expressions, to signify one and the same thing ; and I wish to use common words in their common acceptation. 4. Taking along with us what is said in the last article, to guard us against the se- duction of the analogical language used on this subject, we may observe a very strong analogy, not only between conceiving and painting in general, but between the dif- ferent kinds of our conceptions, and the different works of the painter. He either makes fancy pictures, or he copies from the painting of others, or he paints from the life ; that is, from real objects of art or nature which he has seen. I think our conceptions admit of a division very similar. First, There are conceptions which may be called fancy pictures. They are com- monly called, creatures of fancy, or of im- agination. They are not the copies of any original that exists, but are originals them- selves. Such was the conception which Swift formed of the island of Laputa, and of the country of the Lilliputians ; Cer- vantes of Don Quixote and his Squire ; Harrington of the Government of Oceana ; and Sir Thomas More of that of Utopia. We can give names to such creatures of imagination, conceive them distinctly, and reason consequentially concerning them, though they never had an existence. They were conceived by their creators, and may be conceived by others, but they never existed. We do not ascribe the qualities of true or false to them, because they are not accompanied with any belief, nor do they imply any affirmation or negation. [366] Setting aside those creatures of imagina- tion, there are other conceptions, which may be called copies, because they have an original or archetype to which they refer, and with which they are believed to agree ; and we call them true or false conceptions, according as they agree or disagree with the standard to which they are referred. These are of two kinds, which have different standards or originals. The first kind is analogous to pictures taken from the life. We have conceptions of individual things that really exist, such 364 ON THE INTELLECTUAL POWERS. Qbs3.it IV. as the city of London, or the government of Venice. Here the things conceived are the originals ; and our conceptions are called true when they agree with the thing con- ceived. Thus, my conception of the city of London is true, when I conceive it to be what it really is. Individual things which really exist, being the creatures of God, (though some of them may receive their outward form from man,) he only who made them knows their whole nature ; we know them but in part, and therefore our conceptions of them must in all cases be imperfect and inade- quate ; yet they may be true and just, as far as they reach. The second kind is analogous to the copies which the painter makes from pictures done before. Such I think are the conceptions we have of what the ancients called univer- sals ; that is, of things which belong or may belong to many individuals. These are kinds and species of things ; such as man or elephant, which are species of substances ; wisdom or courage, which are species of qualities ; equality or similitude, which are species of relations.* It may be asked — From what original are these conceptions formed ? And when are they said to be true or false ? [367] It appears to me, that the original from which they are copied — that is, the thing conceived — is the conception or meaning which other men, who understand the language, affix to the same words. Things are parcelled into kinds and sorts, not by nature, but by men. The individual things we are connected with, are so many, that to give a proper name to every indi- vidual would be impossible. We could never attain the knowledge of them that is necessary, nor converse and reason about them, without sorting them according to their different attributes. Those that agree in certain attributes are thrown into one parcel, and have a general name given them, which belongs equally to every indi- vidual in that parcel. This common name must therefore signify those attributes which have been observed to be common to every individual in that parcel, and no- thing else. That such general words may answer their intention, all that is necessary is, that those who use them should affix the same meaning or notion — that is, the same con- ception to them. The common meaning is the standard by which such conceptions are formed, and they are said to be true or * Of. all such we can have no adequate imagination. A universal, when represented in imagination, is no longer adequate, no longer a universal. We cannot have an image of Horse, but only of some individual of that species We may, however, have a notion or conception of it. See below, p. 48*.— H. false according as they agree or disagree with it. Thus, my conception of felony is true and just, when it agrees with the meaning of that word in the laws relating to it, and in authors who understand the law. The meaning of the word is the thing conceived ; and that meaning is the conception affixed to it by those who best understand the language. An individual is expressed in language either by a proper name, or by a general word joined to such circumstances as dis- tinguish that individual from all others ; if it is unknown, it may, when an object of sense, and within reach, be pointed out to the senses ; when beyond the reach of the senses, it may be ascertained by a descrip- tion, which, though very imperfect, may be true, and sufficient to distinguish it from every other individual. Hence it is, that, in speaking of individuals, we are very little in danger of mistaking the object, or tak- ing one individual for another. [368] Yet, as was before observed, our concep- tion of them is always inadequate and lame. They are the creatures of God, and there are many things belonging to them which we know not, and which cannot be deduced by reasoning from what we know. They have a real essence, or constitution of nature, from which all their qualities flow ; but this essence our faculties do not com- prehend. They are therefore incapable of definition ; for a definition ought to com- prehend the whole nature or essence of the thing defined. Thus, Westminster Bridge is an indi- vidual object; though I had never seen or heard of it before, if I am only made to conceive that it is a bridge from West- minster over the Thames, this concep- tion, however imperfect, is true, and is sufficient to make me distinguish it, when it is mentioned, from every other object that exists. The architect may have an adequate conception of its structure, which is the work of man ; but of the materials, which are the work of God, no man has an adequate conception ; and, therefore, though the object may be described, it cannot be defined. Universals are always expressed by gene- ral words ; and all the words of language, excepting proper names, are general words ; they are the signs of general concep- tions, or of some circumstance relating to them. These general conceptions are formed for the purpose of language and reasoning ; and the object from which they are taken, and to which they are intended to agree, is the conception which other men join to the same words ; they may, there- fore, be adequate, and perfectly agree with the thing conceived. This implies no more than that men who speak the same language [367,368] oiiAr. i.] OF SIMPLE APPREHENSION IN GENERAL. 365 may perfectly agree in the meaning of many general words. Thus mathematicians have conceived what they call a plane triangle. They have defined it accurately ; and, when I conceive it to be a plane surface, bounded by three right lines, I have both a true and an adequate conception of it. [369] There is nothing belonging to a plane triangle which is not comprehended in this conception of it, or deducible from it by just reasoning. This definition expresses the whole essence of the thing defined, as every just definition ought to do ; but this essence is only what Mr Locke very properly calls a nominal essence ; it is a general conception formed by the mind, and joined to a general word as its sign. If all the general words of a language had a precise meaning, and were perfectly un- derstood, as mathematical terms are, all verbal disputes would be at an end, and men would never seem to differ in opinion, but when they differ in reality ; but this is far from being the case. The meaning of most general words is not learned, like that of mathematical terms, by an accurate definition, but by the experience we happen to have, by hearing them used in conversa- tion. From such experience, we collect their meaning by a kind of induction ; and, as this induction is, for the most part, lame, and imperfect, it happens that different per- sons join different conceptions to the same general word ; and, though we intend to give them the meaning which use, the arbiter of language, has put upon them, this is difficult to find, and apt to be mis- taken, even by the candid and attentive. Hence, in innumerable disputes, men do not really differ in their judgments, but in the way of expressing them. Our conceptions, therefore, appear to be of three kinds. They are either the concep- tions of individual things, the creatures of God ; or they are conceptions of the mean- ing of general words ; or they are the crea- tures of our own imagination : and these different kinds have different properties, which we have endeavoured to describe. 5. Our conception of things may be strong and lively, or it may be faint and languid in all degrees. These are qualities which pro- perly belong to our conceptions, though we have no names for them but such as are analogical. Every man is conscious of such a difference in his conceptions, and finds his lively conceptions most agreeable, when the object is not of such a nature as to give pain. |370] Those who have lively conceptions, com- monly express them in a lively manner — that is, in such a manner as to raise lively conceptions and emotions in others. Such persons are the most agreeable companions C369-371] in conversation, and the most acceptable in their writings. The liveliness of our conceptions proceeds from different causes- Some objects, from their own nature, or from accidental asso- ciations, are apt to raise strong emotions in the mind. Joy and hope, ambition, zeal, and resentment, tend to enliven our con- ceptions ; disappointment, disgrace, grief, and envy, tend rather to flatten them. Men of keen passions are commonly lively and agreeable in conversation ; and dispassion- ate men often make dull companions. There is in some men a natural strengthtand vigour of mind which gives strength to their con- ceptions on all subjects, and in all the occa- sional variations of temper. It seems easier to form a lively concep- tion of objects that are familiar, than of those that are not ; our conceptions of visible objects are commonly the most lively, when other circumstances are equal. Hence, poets not only delight in the description of visible objects, but find means, by meta- phor, analogy, and allusion, to clothe every object they describe with visible qualities. The lively conception of these makes the object appear, as it were, before our eyes. Lord Karnes, in his Elements of Criticism, has shewn of what importance it is in works of taste, to give to objects described, what he calls ideal presence.* To produce this in the mind, is, indeed, the capital aim of poetical and rhetorical description. It carries the man, as it were, out of himself, and makes him a spectator of the scene described. This ideal presence seems to me, to be nothing else but a lively conception of the appearance which the object would make if really present to the eye. [371] Abstract and general conceptions are never lively, though they may be distinct ; and, therefore, however necessary in philo- sophy, seldom enter into poetical descrip- tion without being particularised or clothed in some visible dress. •(■ It may be observed, however, that our conceptions of visible objects become more lively by giving them motion, and more still by giving them life and intellectual qualities. Hence, in poetry, the whole crea- tion is animated, and endowed with sense and reflection. Imagination, when it is distinguished from conception, seems to me to signify one species of conception — to wit, the con. * The 'Ev^eyUAt 'Ttrarwrmiris, $«*r«W«t "Otytt EiSaAoaW*, Visi&nes, of the ancient Rhetoricians — H. t They thus cease to be aught abstract and general. and become merely individual representations. In precise language, they are no longer vofaiarx, but pmTair^KT* ; no longer Begriffe, but Anscnauungen ; no longer notions or concepts^ but images. Thewor'1 " particularised" ought to have been individualised — H. 366 ON THE INTELLECTUAL POWERS. [K9SAY IV ception of visible objects.* Thus, in a mathematical proposition, I imagine the figure, and I conceive the demonstration ; it would not, I think, be improper to say, I conceive both ; but it would not be so proper to say, I imagine the demonstration. 6". Our conceptions of things maybe clear, distinct, and steady; or they may be ob- scure, indistinct, and wavering. The live- liness of our conceptions gives pleasure, but it is their distinctness and steadiness that enables us to judge right, and to express our sentiments with perspicuity. If we inquire into the cause, why, among persons speaking or writing on the same subject, we find in one so much darkness, in another so much perspicuity, I believe the chief cause will be found to be, that one had a distinct and steady concep- tion of what he said and wrote, and the other had not. Men generally find means to express distinctly what they have con- ceived distinctly. Horace observes, that proper words spontaneously follow distinct conceptions — " Verbaqtie provisam rem non invita sequuntur." But it is impossible that a man should distinctly express what he has not distinctly conceived. [372] We are commonly taught that perspicuity depends upon a proper choice of words, a proper structure of sentences, and a proper order in the whole composition. All this is very true ; but it supposes distinctness in our conceptions, without which there can be neither propriety in our words, nor in the structure of our sentences, nor in our method. Nay, 1 apprehend that indistinct con- ceptions of things are, for the most part, the cause, not only of obscurity in writing and speaking, but of error in judging. Must not they who conceive things in the same manner form the same judgment of their agreements and disagreements ? Is it possible for two persons to differ with regard to the conclusion of a syllogism who have the same conception of the premises ? Some persons find it difficult to enter into a mathematical demonstration. I be- lieve we shall always find the reason to be, that they do not distinctly apprehend it. A man cannot be convinced by what he does not understand. On the other hand, I think a man cannot understand a de- monstration without seeing the force of it. I speak of such demonstrations as those of Euclid, where every step is set down, and nothing left to be supplied by the reader. * It is to be regretted that Reid did not more fully develope the distinction of Imagination and Concep- tion, on which he here and elsewhere Inadequately touches. Imagination is not, though in conformity to the etymology of the term, to be limited to the representation of visible objects. See below, under p. 462. Neither ought the term conceive to be used in the extensive sense of understand.— H. Sometimes one who has got through the first four books of Euclid's " Elements," and sees the force of the demonstrations, finds difficulty in the fifth. What is the reason of this ? You may find, by a little conversation with him, that he has not a clear and steady conception of ratios, and of the terms relating to them. When the terms used in the fifth book have become familiar, and readily excite in his mind a clear and steady conception of their mean- ing, you may venture to affirm that he will be able to understand the demonstrations of that book, and to see the force of them. [373] If this be really the case, as it seems to be, it leads us to think that men are very much upon a level with regard to mere judgment, when we take that faculty apart from the apprehension or conception of the things about which we judge; so that a sound judgment seems to be the inseparable companion of a clear and steady apprehen- sion. And we ought not to consider these two as talents, of which the one may fall to the lot of one man, and the other to the lot of another, but as talents which always go together. It may, however, be observed, that some of our conceptions may be more subservient to reasoning than others which are equally clear and distinct. It was before observed, that some of our conceptions are of indi- vidual things, others of things general and abstract. It may happen that a man who has very clear conceptions of things in- dividually, is not so happy in those of things general and abstract. And this I take to be the reason why we find men who have good judgment in matters of common life, and perhaps good talents for poetical or rhetorical composition, who find it very difficult to enter into abstract reas- oning. That I may not appear singular in put- ting men so much upon a level in point of mere judgment, I beg leave to support this opinion by the authority of two very think ing men, Des Cartes and Cicero. The former, in his dissertation on Method, ex- presses himself to this purpose ; — " Nothing is so equally distributed among men as judgment.* Wherefore, it seems reasonable to believe, that the power of distinguishing what is true from what is false, (which we properly call judgment or right reason,) is by nature equal in all men ; and therefore that the diversity of our opinions does not arise from one person being endowed with a greater power of reason than another, but only from this, that we do not lead our * «* Judgment," bona mens, in the authentic Latin translation. I cannot, at the moment, lay hands on my copy of the French original •, but, if 1 recollect aright, it is there le ton sent H. f3T2,373] chap, i.] OP SIMPLE APPREHENSION IN GENERAL. 367 thought in the same track, nor attend to the same things." Cicero, in his third hook'" De Oratore," makes this observation — " It is wonderful when the learned and unlearned differ so much in art, how little they differ in judg- ment. For art being derived from Nature, is good for nothing, unless it move and delight Nature." [374] From what has been said in this article, it follows, that it is so far in our power to write and speak perspicuously, and to reason justly, as it is in our power to form clear and. distinct conceptions of the subject on which we speak or reason. And, though Nature hath put a wide difference between one man and another in this respect, yet that it is in a very considerable degree in our power to have clear and distinct appre- hensions of things about which we think and reason, cannot be doubted. 7. It has been observed by many authors, that, when we barely conceive any object, the ingredients of that conception must either be things with which we were before acquainted by some other original power of the mind, or they must be parts or attri- butes of such things. Thus, a man cannot conceive colours if he never saw, nor sounds if he never heard. If a man had not a con- science, he could not conceive what is meant by moral obligation, or by right and wrong in conduct. Fancy may combine things that never were combined in reality. It may enlarge or diminish, multiply or divide, compound and fashion the objects which nature pre- sents ; but it cannot, by the utmost effort of that creative power which we ascribe to it, bring any one simple ingredient into its productions which Nature has not framed and brought to our knowledge by some other faculty. This Mr Locke has expressed as beauti- fully as justly. The dominion of man, in this little world of his own understanding, is much the same as in the great world of visible things ; wherein his power, however managed by art and skill, reaches no farther than to compound and divide the materials that are made to his hand, but can do no- thing towards making the least particle of matter, or destroying one atom that is already in being. [375] The same inability will every one find in himself, to fashion in his understanding any simple idea not received by the powers which God has given him. ' I think all philosophers agree in this senti- ment. Mr Hume, indeed, after acknow- ledging the truth of the principle in general, mentions what he thinks a single exception to it — That a man, who had seen all the shades of a particular colour except one, might frame in his mind a conception of that shade which he never saw. I think [374-376] { this is not an exception ; because a parti- cular shade of a colour differs not specifically, but only in degree, from other shades of the same colour. It is proper to observe, that our most simple conceptions are not those which nature immediately presents to us. When we come to years of understanding, we have the power of analysing the objects of nature, of distinguishing their several attributes and relations, of conceiving them one by one, and of giving a name to each, whose meaning extends only to that single attri- bute or relation : and thus our most simple conceptions are not those of any object in nature, but of some single attribute or rela- tion of such objects. Thus, nature presents to our senses bodies that are extended in three dimensions, and solid. By analysing the notion we have of body from our senses, we form to our- selves the conceptions of extension, solidity, space, a point, a line, a surface — all which are more simple conceptions than that of a body. But they are the elements, as it were, of which our conception of a body is made up, and into which it may be analysed. This power of analysing objects we propose to consider particularly in another place. It is only mentioned here, that what is said in this article may not be understood so as to be inconsistent with it. [376] 8. Though our conceptions must be con- fined to the ingredients mentioned in the last article, we are unconfined with regard to the arrangement of those ingredients. Here we may pick and choose, and form an endless variety of combinations and com- positions, which we call creatures of the imagination. TheBe may be clearly con- ceived, though they never existed : and, indeed, everything that is made, must have been conceived before it was made. Every work of human art, and every plan of con- duct, whether in public or in private life, must have been conceived before it was brought to execution. And we cannot avoid thinking, that the Almighty, before he created the universe by his power, had a distinct conception of the whole and of every part, and saw it to be good, and agreeable to his intention. It is the business of man, as a rational creature, to employ this unlimited power of conception, for planning his conduct and enlarging his knowledge. It seems to be peculiar to beings endowed with reason to act by a preconceived plan. Brute animals seem either to want this power, or to have it in a very low degree. They are moved by instinct, habit, appetite, or natural affec- tion, according as these principles are stirred by the present occasion. But I see no reason to think that they can propose to themselves a connected plan of life, or form 368 ON THE INTELLECTUAL POWERS. (JEgSAT IY. general rules of conduct Indeed, we see that many of the human species, to whom God has given this power, make little use of it. They act without a plan, as the pas- sion or appetite which is strongest at the time leads them. 9. The last property I shall mention of this faculty, is that which essentially dis- tinguishes it from every other power of the mind ; and it is, that it is not employed solely about things which have existence. I can conceive a winged horse or a centaur, as easily and as distinctly as I can conceive a man whom I have seen. Nor does this distiuct conception incline my judgment in the least to the belief that a winged horse or a centaur ever existed. [377] It is not so with the other operations of our minds. They are employed about real existences, and carry with them the belief of their objects. When I feel pain, I am compelled to believe that the pain that I feel has a real existence. When I perceive any external object, my belief of the real existence of the object is irresistible. When I distinctly remember any event, 'though that event may not now exist, I can have no doubt but it did exist. That conscious- ness which we have of the operations of our own minds, implies a belief of the real existence of those operations. Thus we see, that the powers of sensa- tion, of perception, of memory, and of con- sciousness, are all employed solely about objects that do exist, or have existed. But conception is often employed about objects that neither do, nor did, nor will exist. This is the very nature of this faculty, that its object, though distinctly conceived, may have no existence. Such an object we call a creature of imagination ; but this creature never was created. That we may not impose upon ourselves in this matter, we must distinguish between that act or operation of the mind, which we call conceiving an object, and the object which we conceive. When we conceive anything, there is a real act or operation of the mind. Of this we are conscious, and can have no doubt of its existence. But every such act must have an obj ect ; • for he that conceives must conceive something. Suppose he conceives a centaur, he may have a distiuct conception of this object, though no centaur ever existed. I am afraid that, to those who are unac- quainted with the doctrine of philosophers upon this subject, I shall appear in a very ridiculous light, for insisting upon a point so very evident as that men may barely conceive things that never existed. They will hardly believe that any man in his wits ever doubted of it. Indeed, I know no * See below, p. 390, and Note B.— H. truth more evident to the common sense and to the experience of mankind. But, if the authority of philosophy, ancient and modern, opposes it, as I think it does, I wish not to treat that authority so fastidiously as not to attend patiently to what may be said- in support of it. [378] CHAPTER II. THEORIES CONCERNING CONCEPTION. The theory of ideas has been- applied to the conception of objects, as well as to per- ception and memory. Perhaps it will be irksome to the reader, as it is to the writer, to return to that subject, after so much has been said upon it ; but its application to the conception of objects, which could hot. pro- perly have been introduced before, gives a more comprehensive view of it, and of the prejudices which have led philosophers so unanimously into it. There are two prejudices which seem to me to have given rise to the theory of ideas in all the various forms in which it has ap- peared in the course of above two thousand years ; and, though they have no support from the natural dictates of our faculties, or from attentive reflection upon their oper- ations, they are prejudices which those who speculate upon this subject are very apt to be led into by analogy. The first is — That, in all the operations of the understanding, there must be some im- mediate intercourse between the mind and its object, so that the one may act upon the other. The second, That, in all the opera- tions of understanding, there must be an object of thought, which really exists while we think of it ; or, as some philosophers have expressed it, that which is not cannot be intelligible. Had philosophers perceived that these are prejudices grounded only upon analogical reasoning, we had never heard of ideas in the philosophical sense of that word. [379] The first of these principles has led philo- sophers to think that, as the external objects of sense are too remote to act upon the mind immediately, there must be some image or shadow of them that is present to the mind, and is the immediate object of perception. That there is such an imme- diate object of perception, distinct from the external object, has been very unani- mously held by philosophers, though they have differed much about the name, the * The reader will bear in mind what has been already said of the limited meaning attached by Reid to the term Idea, viz., something in, or present to the mind, but not a mere modification of the mind— and his error in supposing that all philosophers admitted this crude hypothesis. See Notes B, C, L, M, N, O, P, &c— H. [3TT-S7»] chap, ii.] THEORIES CONCERNING CONCEPTION. ;?«a nature, and the origin of those immediate olijects. We have considered what has been said in the support of this principle, Essay II. chap. 14, to which the reader is referred, to prevent repetition. I shall only add to what is there said, That there appears no shadow of reason why the mind must have an object imme- diately present to it in its intellectual oper- ations, any more than in its affections and passions. Philosophers have not said that ideas are the immediate objects of love or resentment, of esteem or disapprobation. It is, I think, acknowledged, that persons and not ideas, are the immediate objects of those affections ; persons, who are as far from being immediately present to the mind as other external objects, and, sometimes, persons who have now no existence, in this world at least, and who can neither act upon the mind, nor be acted upon by it. The second principle, which I conceive to be likewise a prejudice of philosophers, grounded upon analogy, is now to be considered. It contradicts directly what was laid down in the last article of the preceding chapter — to wit, that we may have a distinct con- ception of things which never existed. This is undoubtedly the common belief of those who have not been instructed in philosophy ; and they will think it as ridiculous to defend it by reasoning, as to oppose it. [380] The philosopher says, Though there may be a remote object which does not ex- ist, there must be an immediate object which really exists ; for that which is not, cannot be an object of thought. The idea must be perceived by the mind, and, if it does not exist there, there can be no per- ception of it, no operation of the mind about it.* This principle deserves the more to be examined, because the other before men- tioned depends upon it ; for, although the last may be true, even if the first was false, yet, if the last be not true, neither can the first. If we can conceive objects which have no existence, it follows that there may be objects of thought which neither act upon the mind, nor are acted upon by it ; because that which has no existence can neither act nor be acted upon. It is by these principles that philosophers have been led to think that, in every act of memory and of conception, as well as of perception, there are two objects — the one, the immediate object, the idea, the species, the form ; the other, the mediate or external object. The vulgar know only * In relation to this and what follows, see above. ». 293, b, note t ; p. 2TO, a, note t ; and Note B. 380,3811 of one object, which, in perception, is some- thing external that exists ; in memory, something that did exist ; and, in concep- tion, may be something that never existed.* But the immediate object of the philo- sophers, the idea, is said to exist, and to be perceived in all these operations. These principles have not only led philo- sophers to split objects into two, where others can find but one, but likewise have led them to reduce the three operations now mentioned to one, making memory and con- ception, as well as perception, to be the per- ception of ideas. But nothing appears more evident to the vulgar, than that what is only remembered, or only conceived, is not perceived ; and, to speak of the perceptions of memory, appears to them as absurd as to speak of the hearing of sight. [301 ] In a word, these two principles carry us into the whole philosophical theory of ideas, and furnish every argument that ever was used for their existence. If they are true, that system must be admitted with all its consequences. If they are only prejudices, grounded upon analogical reasoning, the whole system must fall to the ground with them. It is, therefore, of importance to trace those principles, as far as we are able, to their origin, and to see, if possible, whether they have any just foundation in reason, or whether they are rash conclusions, drawn from a supposed analogy between matter and mind. The unlearned, who are guided by the dictates of nature, and express what they are conscious of concerning the operations of their own mind, believe that the object which they distinctly perceive certainly exists ; that the object which they distinctly remember certainly did exist, but now may not ; but as to things that are barely con- ceived, they know that they can conceive a thousand things that never existed, and that the bare conception of a thing does not so much as afford a presumption of its exist- ence. They give themselves no trouble to know how these operations are performed, or to account for them from general principles. But philosophers, who wish to discover the causes of things, and to account for these operations of mind, observing that in other operations there must be not only an agent, but something to act upon, have been led by analogy to conclude that it must be so in the operations of the mind. The relation between the mind and its conceptions bears a very strong and obvious analogy to the relation between a man and his work. Every scheme he forme, every discovery he makes by his reasoning powers, is very properly called the work of his mind. These works of the mind are sometime s * See references in precedrng note.— .H. 9b 37Q ON THE INTELLECTUAL POWERS. say ir. great and important works, and draw the attention and admiration of men. [382] It is the province of the philosopher to consider how such works of the mind are produced, and of what materials they are composed. He calls the materials ideas. There must therefore be ideas, which the mind can arrange and form m into a regular structure. Everything that is produced, must be produced of something ; and from nothing, nothing can be produced. Some such reasoning as this seems to me to have given the first rise to the philoso- phical notions of ideas. Those notions were formed into a system by the Pythagoreans, two thousand years ago ; and this system was adopted by Plato, and embellished with all the powers of a fine and lofty imagina- tion. I shall, in compliance with custom, call it the Platonic system of ideas, though in reality it was the invention of the Pytha- gorean school. " The most arduous question which em- ployed the wits of men in the infancy of the Grecian philosophy was — What was the origin of the world ? — from what principles and causes did it proceed ? To this ques- tion very different answers were given in the different schools. Most of them appear to us very ridiculous. The Pythagoreans, however, judged, very rationally, from the order and beauty of the universe, that it must be the workmanship of an eternal, in- telligent, and good being : and therefore they concluded the Deity to be one first principle or cause of the universe. But they conceived there must be more. The universe must be made of something. Every workman must have materials to work upon. That the world should be made out of nothing seemed to them absurd, be- cause everything that is made must be made of something. Nullam rem e nihilo gigni divimtus unquam. — LucR. L)e nibilo nihil, in nihilum nil posse reverti.— Peiih. This maxim never was brought into doubt : even in Cicero's time it continued to be held by all philosophers. [383] What natural philosopher (says that author in his second book of Divination) ever asserted that anything could take its rise from nothing, or be reduced to nothing ? Be- cause men must have materials to work upon, they concluded it must be so with the Deity. This was reasoning from analogy. From this it followed, that an eternal uncreated matter was another first prin- ciple of the universe. But this matter they believed had no form nor quality. It was * Ideas in the Platonic, and Ideas in the modern signification, hold, as I have already shewn, little or no analogy to each other. See above, p. 204, a, notes t t i p. 225, b, note * ; p. 202, b, note *.— H. the same with the materia prima or first matter of Aristotle, who borrowed this part of his philosophy from his predecessors. To us it seems more rational to think that the Deity created matter with its qua- lities, than that the matter of the universe should be eternal and self-existent. But so strong was the prejudice of the ancient philosophers against what we call creation, that they rather chose to have recourse to this eternal and unintelligible matter, that the Deity might have materials to work upon. The same analogy which led them to think that there must be an eternal matter of which the world was made, led them also to conclude that there must be an eternal pattern or model according to which it was made- Works of design and art must be distinctly conceived before they are made. The Deity, as an intelligent Being, about to execute a. work of perfect beauty and regularity, must have had a distinct con- ception of his work before it was made. ■ This appears very rational. But this conception, being the work of the Divine intellect, something must have existed as its object. This could only be ideas, which are the proper and immediate object of intellect. [384] From this investigation of the principles or causes of the universe, those philoso-. pliers concluded them to he three in number — to wit, an eternal matter as the material . cause, eternal ideas as the model or exem- plary cause, and an eternal intelligent mind as the efficient cause. As to the nature of those eternal ideas, the philosophers of that sect ascribed to them the most magnificent attributes. They were immutable and uncreated ;* the object of the Divine intellect before the world was made ; and the only object of intellect and of science to all intelligent beings. As far as intellect is superior to sense, so far are ideas superior to all the objects of sense. The objects of sense being in a constant flux, cannot properly be said to exist. Ideas are the things which have a real and permanent exist- ence. They are as various as the species of things, there being one idea of every spe- cies, but none of individuals. The idea is the essence of the species, and existed be- fore any of the species was made. It is entire in every individual of the species, without being either divided or multiplied. In our present state, we have but an imperfect conception of the eternal ideas ; but it is the highest felicity and perfection of men to be able to contemplate them. * Whether, in the Platonic system, Ideas are, or are not, independent of the Deity, I have already stated, is, and always has Ven, a vexata quastio.— [382-384] chap. h.J THEORIES CONCERNING CONCEPTION. 371 While we are in this prison of the body, I sense, as a dead weight, bears us down from the contemplation of the intellectual objects ; and it is only by a due purifica- tion of the soul, and abstraction from sense, that the intellectual eye is opened, and that we are enabled to mount upon the wings of intellect to the celestial world of ideas. Such was the most ancient system con- cerning ideas, of which we have any account. And, however different from the modern, it appears to be built upon the prejudices we have mentioned — to wit, that in every operation there must be something to work upon ; and that even in conception there must be an object which really exists. [385] For, if those ancient philosophers had thought it possible that the Deity could operate without materials in the formation of the world, and that he could conceive the plan of it without a model, they could have seen no reason to make matter and ideas eternal and necessarily existent prin- ciples, as well as the Deity himself. Whether they believed that the ideas were not only eternal, but eternally, and without a cause, arranged in that beautiful and perfect order which they ascribe to this intelligible world of ideas, I cannot say ; but this seems to be -a, necessary conse- quence of the system : for, if the Deity could not conceive the plan of the world which he made, without a model which really existed, that model could not be his work, nor contrived by his wisdom ; for, if he made it, he must have conceived it before it was made ; it must therefore have existed in all its beauty and order inde- pendent of the Deity ; and this I think they acknowledged, by making the model and the matter of this world, first princi- ples, no less than the Deity. If the Platonic system be thus understood, (and I do not see how it can hang together otherwise,) it leads to two consequences that are unfavourable to it. Firsl, Nothing is left to the Maker of this world but the skill to work after a model. The model had all the perfection and beauty that appears in the copy, and the Deity had only to copy after a pattern that existed independent of him. Indeed, the copy, if we believe those philosophers, falls very far short of the original ; but this they seem to have ascribed to the refracto- riness of matter of which it was made.i Secondly, If the world of ideas, without being the work of a perfectly wise and good intelligent being, could have so much beauty and perfection, how can we infer from the beauty and order of this world, which is but an imperfect copy of the other, that it must have been made by a perfectly wise and good being ? [386] The force of this £385-387 ] reasoning, from the beauty and order of the untvertc', to its being the work of a wise being, which appears invincible to every candid mind, and appeared so to those ancient philosophers, is entirely destroyed by the supposition of the existence of a world of ideas, of greater perfection and beauty, which never was made. Or, if the reasoning be good, it will apply to the world of ideas, which must, of consequence, have been made by a wise and good intelligent being, and must have been conceived before it was made. It may farther be observed, that all that is mysterious and unintelligible in the Pla- tonic ideas, arises from attributing existence to them. Take away this one attribute, all the rest, however pompously expressed, are easily admitted and understood. What is a, Platonic idea? It is the essence of a species. It is the exemplar, the model, according to which all the individuals of that species are made. It is entire in every individual of the species, without be- ing multiplied or divided. It was an object of the divine intellect from eternity, and is an object of contemplation and of science to every intelligent being. It is eternal, im- mutable, and uncreated ; and, to crown all, it not only exists, but has a more real and permanent existence than anything that ever God made. Take this description altogether, and it would require an GEdipus to unriddle it. But take away the last part of it, and no- thing is more easy. It is easy to find five hundred things which answer to every article in the description except the last. Take, for an instance, the nature of a circle, as it is defined by Euclid — an object which every intelligent being may conceive distinctly, though no circle had ever existed; it is the exemplar, the model, according to which all the individual figures of that species that ever existed were made ; for they are all made according to the nature of a circle. [387] It is entire in every individual of the species, without being multiplied or divided. For , every circle is an entire circle ; and all circles, in as far as they are circles, have one and the same nature. It was an object of the divine intellect from all eternity, and may be an object of con- templation and of science to every intelli- gent being. It is the essence of a species, and, like all other essences, it is eternal, immutable, and uncreated. This means no more but that a circle always was a circle, and can never be anything but a circle. It is the necessity of the thing, and not any act of creating power, that makes a circle to be a circle. Tlie nature of every species, whether of substance, of quality, or of relation, and in general everything which the ancients called 2 B 2 372 ON THE INTELLECTUAL POWERS. L essay IV. an universal, ai.swers to the description of a Platonic idea, if in that description you leave out the attribute of existence. If we believe that no species of things could be conceived by the Almighty with- out a model that really existed, we must go back to the Piatouic system, however mys- terious. But, if it be true that the Deity could have a distinct conception of things wliich did notexist, and that other intelligent beings may conceive objects which do not e iist, the system has no better foundation than this prejudice, that the operations of mind must be like those of the body. Aristotle rejected the ideas of his master Piato as visionary ; but he retained the prejudices that gave rise to them, and there- fore substituted something in their place, but under a different name,* and of a dif- ferent origin. He called the objects of intellect, intelli- gible species ; those of the memory and imagination, phantasms ; and those of the senses, sensible species. This change of the name* was indeed very small ; for the Greek word of Aristotle [tXSer] which we translate species or form, is so near to the Greek word idea, both in its sound and significa- tion, that, from their etymology, it would not be easy to give them different meanings. [388] Both are derived from theGreekword which signifies to see, and both may signify a vision or appearanee to the eye. Cicero, who understood Greek well, often translates the Greek word idea by the Latin word visio. But both words being used as terms of art — one in the Platonic system, the other in the Peripatetic — the Latin writers generally borrowed the Greek word idea to express the Platonic notion, and translated Aristotle's word, by the words species or forma ; and in this they have been followed in the modern languages. * Those forms or species were called intelli- gible, to distinguish them from sensible speetes, which Aristotle held to be the imme- diate objeets of sense. He thought that the sensible species come from the external object, and denned a sense to be that which has the capacity to receive the form of sensible things without the mat- ter ; as wax receives the form of a seal with- out any of the matter of it. In like manner, he thought thai the intellect receives the forms of things intelligible ; and he callsit the place of forms. * Reid seems not aware that Plato, and Aristotle in relation to Plato, employed the terms iTSet and litcc almost as convertible. In fact, the latter usually combats the ideal theory of the former by the name of sTSaj — e. e., t« ei'3»j x&'cim, Tt^r'nrfjutrx yxq Is"'. M. Cousin, in a learned and ingenious paper of his " Nouveaux Fragments" has endeavoured to shew that iMaco did not apply the two terms indifferently ; and the- same has been attempted by Richter. But so many exceptions' must be admitted, that, appa- rently, no determinate rule can be established H. I take it to have been the opinion of Aris- totle, that the intelligible forms in the hu- man intellect are derived from the sensible by abstraction, and other operations of the mind itself- As to the intelligible forms in the divine intellect, they must have had another origin ; but I do not remember that he gives any opinion about them. He cer- tainly maintained, however, that there is no intellection without intelligible species;* no memory or imagination without phan- tasms ; no perception without sensible species. Treating of memory, he proposes a difficulty, and endeavours to resolve it — how a phantasm, that is a present object in the mind, should represent a thing that is past. [389] Thus, I think, it appears that the Per- ipatetic system of species and phantasms, as well as the Platonic system of ideas, is grounded upon this principle, that in every kind of thought there must be some object that really exists ; in every operation of the mind, something to work upon. Whether this immediate object be called an idea with Plato, -f* or a phantasm or species with Aris- totle — whether it be eternal and uncreated, or produced by the impressions of external objects — is of no consequence in the pre- sent argument. In both systems, it was thought impossible that the Deity could make the world without matter to work upon ; in both, it was thought impossible that an intelligent Being could conceive anything that did not exist, but by means of a model that really existed. The philosophers of the Alexandrian school, commonly called the latter Flato- nists, conceived the eternal ideas of things to be in the Divine intellect, aud thereby avoided tlie absurdity of making them a principle distinct from and independent of the Deity ; but still they held them to exist really in the Divine mind as the objeets of conception, and as the patterns and arche- types of things that are made. Modern philosophers, still persuaded that of every thought there must be an imme- diate object that really exists, have not deemed it necessary to distinguish by dif- ferent names the immediate objects of in- tellect, of imagination, and of the senses, but have given the common name of idea to them all. Whether these ideas be in the sensorium, or in the mind, or partly hi the one and partly in the other; whether they exist when they are not perceived, or only when * There is, even less reason to attribute such a theory to Aristotle in relation to the intellect than in relation to sense and imagination. See even his oldest commentatw, the Aphrodisian, JltetWurvs, f. 1:19, a. In fact, tue greater number of those Peri, patetics who admitted species in this crude form lot the latter, rejected -them for the former. H. i Sec auoie, p. 26.', h, note * H. f388 3S9~] CHAP. IT. IHEORIES CONCERNING CONCEPTION. 373 they are perceived ; whether they are the workmanship of the Deity or of the mind itself, or of external natural causes — with regard to these points, different authors seem to have different opinions, and the same author sometimes to waver or be diffident ; but as to their existence, there seems to be great unanimity.* [390] So much is this opinion fixed in the minds of philosophers, that I doubt not but it will appear to most a very strange para- dox, or rather a contradiction, that men should think without ideas. That it has the appearance of a contra- diction, I confess. But this appearance arises from the ambiguity of the word idea. If the idea 1 >f a thing means only the thought of it, or the operation of the mind in think- ing about it, which is the most common meaning of the word, to think without ideas, is to think without thought, which is un- doubtedly a contradiction. But an idea, according to the definition given of it by philosophers, is not thought, but an object of thought, which really exists and is perceived. Now, whether is it a contradiction to say, that a man may think of an object that does not exist ? I acknowledge that a man cannot per- ceive an object that does not exist ; nor can he remember an object that did not exist ; but there appears to me no contradiction in his conceiving an object that neither does nor ever did exist. Let us take an example. I conceive a, centaur. This conception is an operation of the mind, of which I am conscious, and to which I can attend. The sole object of it is a centaur, an animal which, I believe, never existed. I can see no contradiction in this. - )- The philosopher says, I cannot conceive a centaur without having an idea of it in my mind. I am at a loss to understand what he means. He surely does not mean that I cannot conceive it without conceiving it. This would make me no wiser. What then is this idea f Is it an animal, half horse and half man ? No. Then I am certain it is not the thing I conceive. Per- haps he will say, that the idea is an image of the animal, and is the immediate object of my conception, and that the animal is the mediate or remote object. J [391 ] To this I answer — First, I am certain there are not two objects of this conception, but one only ; and that one is as immediate an object of my conception as any can be. Secondly, This one object which I con- ceive, is not the image of an animal — it is * This, as already once and again stated, is not correct.— H. t See above, p. 20?, h, note \, and Note B.— H. $ On this, and the subsequent reasoning in the present chapter, see Note B. — H. an animal. I know what it is to conceive an image of an animal, and what it is to conceive an animal ; and I can distinguish the one of these from the other without any danger of mistake. The thing I con- ceive is a body of a certain figure and colour, having life and spontaneous motion. The philosopher says, that the idea is an image of the animal ; but that it has neither body, nor colour, nor life, nor spontaneous motion. This I am not able to comprehend. Thirdly, I wish to know how this idea comes to be an object of my thought, when I cannot even conceive what it means ; and, if I did conceive it, this would be no evidence of its existence, any more than my conception of a centaur is of its exist- ence. Philosophers sometimes say that we perceive ideas, sometimes that we are con- scious of them. I can have no doubt of the existence of anything which I either perceive or of which I am conscious ;* but I cannot find that I either perceive ideas or am conscious of them. Perception and consciousness are very different operations, and it is strange that philosophers have never determined by which of them ideas are discerned + This is as if a man should positively affirm that he perceived an object ; but whether by his eyes, or his ears, or his touch, he could not say. But may not a man who conceives a centaur say, that he has a distinct image of it in his mind ? I think he may. And if he means by this way of speaking what the vulgar mean, who never heard of the phi- losophical theory of ideas, I find no fault with it. [392] By a distinct image in the mind, the vulgar mean a distinct concep- tion ; and it is natural to call it so, on account of the analogy between an image of a thing and the conception of it. On ac- count of this analogy, obvious to all man- kind, this operation is called imagination, and an image in the mind is only a peri- phrasis for imagination. But to infer from this that there is really an image in the mind, distinct from the operation of con- ceiving the object, is to be misled by an analogical expression ; as if, from the phrases of deliberating and balancing things in the mind, we should infer that there is really a balance existing in the mind for weighing motives and arguments. The analogical words and phrases used in all languages to express conception, do, no doubt, facilitate their being taken in a literal sense. But, if we only attend care- * This is not the case, unless it be admitted that we are conscious of what we perceive— iD other words, immediately cognitive of the non-ego — H. f But the philosophers did not, like Rrid, make Consciousness one special faculty, and Perception ami! her; nor did they and Keidmeaii.by I'ecception the same thing.— H. [ 390-392] d74 ON THE INTELLECTUAL POWERS. [_ESSAY IV. fully to what we are conscious of in this operation, we shall find no more reason to think that images do really exist in our minds, than that balances and other me- chanical engines do. We know of nothing that is in the mind but by consciousness, and we are conscious of nothing but various modes of thinking ; such as understanding, willing, affection, passion, doing, suffering. If philosophers choose to give the name of an idea to any mode of thinking of which we are conscious, I have no objection to the name, but that it introduces a foreign word into our lan- guage without necessity, and a word that is very ambiguous, and apt to mislead. But, if they give that name to images in the mind, which are not thought, but only objects of thought, I can see no reason to think that there are such things in nature. If they be, their existence and their nature must be more evident than anything else, because we know nothing . but by their means. I may add, that, if they be, we can know nothing besides them. For, from the existence of images, we can never, by any just reasoning, infer the existence of anything else, unless perhaps the existence of an intelligent Author of them. In this, Bishop Berkeley reasoned right. [393] In every work of design, the work must be conceived before it is executed— that is, before it exists. If a model, consisting of ideas, must exist in the mind, as the ob- ject of this conception, that model is a work of design no less than the other, of which it is the model ; and therefore, as a work of design, it must have been conceived before it existed. In every work of design, there- fore, the conception must go belore the existence. This argument we applied be- fore to the Platonic system of eternal and immutable ideas, and it may be applied with equal force to all the systems of ideas. If now it should be asked, What is the idea of a circle ? I answer, It is the con- ception of a circle. What is the immediate object of this conception ? The immediate and the only object of it is a circle. But where is this circle ? It is nowhere. If it was an individual, and had a real ex- istence, it must have a place ; but, being an universal, it has no existence, and therefore no place. Is it not in the mind of him that conceives it ? The conception of it is in the mind, being an act of the mind ; and in common language, a thing being in the mind, is a figuratiTe expression, signify- ing that the thing is conceived or remem- bered. It may be asked, Whether this concep- tion is an image or resemblance of a. circle ? I answer, I have already accounted for its bciiiir, in a figurative sense, called the image of a circle in the mind. If the question is meant in the literal sense, we must observe, that the word conception has two meanings. Properly it signifies that operation of the mind which we have been endeavouring to explain ; but sometimes it is put for the object of conception, or thing conceived. Now, if the question be understood in tho last of these senses, the object of this con- ception is not an image or resemblance of a circle ; for it is a circle, and nothing can be an image of itself. [394] If the question be -Whether the opera- tion of mind in conceiving a circle be an image or resemblance of a circle ? I think it is not ; and that no two things can be more perfectly unlike, than a species of thought and a species of figure. Nor is it more strange that conception should have no resemblance to the object conceived, than that desire should have no resem- blance to the object desired, or resentment to the object of resentment. I can likewise conceive an individual object that really exists, such as St Paul's Church in London. I have an idea of it ; that is, I conceive it. The immediate object of this conception is four hundred miles distant ; and I have no reason to think that it acts upon me, or that I act upon it ; but I can think of it notwithstanding. I can think of the first year or the last year of the Julian period. If, after all, it should be thought that images in the mind serve to account for this faculty of conceiving things most distant in time and place, and even things which do not exist, which otherwise would be alto- gether inconceivable ; to this I answer, that accounts of things, grounded upon conjecture, have been the bane of true philosophy in all ages. Experience may satisfy us that it is an hundred times more probable that they are false than that they are true. This account of the faculty of conception, by images in the mind or in the brain, will deserve the regard of those who have a true taste in philosophy, when it is proved by solid arguments— First, That there are images in the.mind, or in the brain, of the things we conceive. Secondly, That there is a faculty in the mind of perceiving such images. Thirdly, That the perception of such images produces the conception of things most distant, and even of things that have no existence. And, fnurthly, That the perception of individual images in the mind, or in the brain, gives us the concep- tion of universals, which are the attributes of many individuals. [395] Until this is done, the theory of images existing in the mind or in the brain, ought to be placed in the same category with the sensible species, materia prima of Aristotle, and the vortices of Dcs Cartes. r393-395l chap. in. J MISTAKES CONCERNING CONCEPTION. 375 CHAPTER III. MISTAKES CONCERNING CONCEPTION. 1. Writers on logic, after the example of Aristotle, divide the operations of the understanding into three : Simple Appre- hension, (which is another word for Con- ception,) Judgment, and Reasoning. They teach us, that reasoning is expressed by a syllogism, judgment by a proposition, and simple apprehension by a term only — that is, by one or more words which do not make u fall proposition, but only the sub- ject or predicate of a proposition. If, by this they mean, as I think they do, that a proposition, or even a syllogism, may not be simply apprehended,* I believe this is a mistake. . In all judgment and in all reasoning, conception is included. We can neither judge of a proposition, nor reason about it, unless we conceive or apprehend it. We may distinctly conceive a proposition, with- out judging of it at all. We may have no evidence on one side or the other ; we may have no concern whether it be true or false. In these cases we commonly form no judg- ment about it, though we perfectly under- stand its meaning, -f A man may discourse, or plead, or write, for other ends than to find the truth. His learning, and wit, and invention may be employed, while his judgment is not at all, or very little. When it is not truth, but some other end he pursues, judgment would be an impediment, unless for discovering the means of attaining his end ; and, there- fore, it is laid aside, or employed solely for that purpose. [3!>6] The business of an orator is said to be, to find out what is fit to persuade. This a man may do with much ingenuity, who never took the trouble to examine whether it ought to persuade or not. Let it not be thought, therefore, that a man judges of the truth of every proposition he utters, or hears uttered. In our commerce with the world, judgment is not the talent that bears the greatest price ; and, therefore, those who are not sincere lovers of truth, lay up this talent where it rusts and corrupts, while they carry others to market, for which there is greater demand. 2. The division commonly made by logi- * Does Reid hero mean, by apprehending pimply, apprehending in one simple and indivisible aft ? — H. T There is no conception po..s ; ble without a judg- ment affirming its (ideal) existence. "There is no consciousness, in fact, possible without judgment. See above, p. 243, a, note *. It is to be observed, that Reid uses conception in the course of this chap- ter as convertible with understanding or comprehen- sion,- and, therefore, as we shall see, in a vaguer or m^re extensive meaning than the philosophers whose opinion he controvei t.- — H. cians, of simple apprehension, into Sensation, Imagination, and Pure Intellection, seems to me very improper in several respects. First, Under the word sensation, they include not only what is properly so called, but the perception of external objects by the senses. These are very different opera- tions of the mind ; and, although they are commonly conjoined by nature, ought to be carefully distinguished by philosophers. Secondly, Neither sensation northe percep- tion of external objects, is simple apprehen- sion. Both includejudgmentand belief, which are excluded from simple apprehension.* Thirdly, They distinguish imagination from pure intellection by this, that, in imagination, the image is in the brain ;•!- in pure intellection, it is in the intellect. This is to ground a distinction upon an hypo- thesis. We have no evidence that there are images either in the brain or in the in- tellect. [397] I take imagination, in its most proper sense, to signify a lively conception of objects of sight. J This is a talent of im- portance to poets and orators, and deserves a proper name, on account of its connection with those arts. According to this strict meaning of the word, imagination is dis- tinguished from conception as a part from the whole. We conceive the objects of the other senses, but it is not so proper to say that we imagine them. We conceive judg- ment, reasoning, propositions, and argu- ments ; but it is rather improper to say that we imagine these things. This distinction between imagination and conception, may be illustrated by an ex- ample, which Des Cartes uses to illus- trate the distinction between imagination and pure intellection. We can imagine a triangle or a square so clearly as to distinguish them from every' other figure. But we cannot imagine a figure of a thou- sand equal sides and angles so clearly. The best eye, by looking at it, could not distin- guish it from every figure of more or fewer sides. And that conception of its appear- ance to the eye, which we properly call im- agination, cannot be more distinct than the appearance itself; yet we can conceive a figure of a thousand sides, and even can demonstrate the properties which distinguish it from all figures of more or fewer sides. It is not by the eye, but by a superior fa- culty, that we form the notion of a great * See the last note.— H.' f But not the image, of which the mind :s con- scious. By image or idea in the brain, species im- prcssa, 8)C, was meant only the unknown corporeal antecedent of' the known mental consequent, -the image or idea in the mind, the species expressa, S;c. Reid here refers principally to the Cartesian doctrine — H. t See above, p. 3C>6, a, note * ; and, below, unde. p. 4a.'.- H. f396, 397"| &7S ON THE INTELLECTUAL POWERS. [_ESSAY IV. number, such as a thousand. And a distinct notion of this number of sides not being to be got by the eye, it is. not imagined, but it is distinctly conceived, and easily distin- guished from every other number. • 3. Simple apprehension is commonly re- presented as the first operation of the understanding ; and judgment, as being a composition or combination of simple appre- hensions. This mistake has probably arisen from the taking sensation, and the perception of objects by the senses, to be nothing but simple apprehension. They arc, very pro- bably, the first operations of the mind ; but they are not simple apprehensions, f [398] It is generally allowed, that we cannot conceive sounds if we have never heard, nor colours if we have never seen ; and the .same thing may be said of the objects of the other senses. In like manner, we must have judged or reasoned before we have the conception or simple apprehension of j ttdgment and of reasoning. Simple apprehension, therefore, though it be the simplest, is not the first operation of the understanding ; and, instead of say- ing that the more complex operations of the mind are formed by compounding sim- ple apprehensions, we ought rather to say, that simple apprehensions are got by ana- lysing more complex operations. A similar mistake, which is carried through the whole of Mr Locke's Essay, may be here mentioned. It is, that our simplest ideas or conceptions are got im- mediately by the senses, or by conscious- ness, and the complex afterwards formed by compounding them. I apprehend it is far otherwise. Nature presents no object to the senses, or to consciousness, that is not complex. Thus, by our senses we perceive bodies of various kinds ; but every body' is a com- plex object ; it has length, breadth, and thickness; it has figure, and colour, and various other sensible qualities, which are blended together in the same subject ; and 1 apprehend that brute animals, who have the same senses that we have, cannot sepa- rate the different qualities belonging to the same subject, and have only a complex and confused notion of the whole. Such also would be our notions of the objects of sense, if we had not superior powers of understanding, by which we can analyse the complex object, abstract every parti- cular attribute from the rest, and form a distinct conception of it. So that it is not by the senses imme- * See above, p. 3(i6, a, note * H. t They are not simple apprehensions, in one sense — that is, the objects arc not incorapositc. Hut this was not the meaning in which the expression was used | by the Logicians.— H. diately, but rather by the powers of ana- lysing and abstraction, that we get the most simple and the most distinct notions even of the objects of sense. This will be more fully explained in another place. [399] 4. There remains another mistake con- cerning conception, which deserves to be noticed. It is — That our conception of things is a test of their possibility, so that, what we can distinctly conceive, we may conclude to be possible ; and of what is im- possible, we can have no conception. This opinion has been held by philoso- phers for more than an hundred years, without contradiction or dissent, as far as I know ; and, if it be an error, it may be of some use to inquire into its origin, and the causes that it has been so generally re- ceived as a maxim whose truth could not be brought into doubt. One of the fruitless questions agitated among the scholastic philosophers in the dark ages* was — What is the criterion of truth ? as if men could have any other way to distinguish truth from error, but by the right use of that power of judging which God has given them. Des Cartes endeavoured to put an end to this controversy, by making it a fundamen- tal principle in his system, that whatever we clearly and distinctly perceive, is true.y To understand this principle of Des Cartes, it must be observed, that he gave the name of perception to every power of the human understanding ; and in explain- ing this very maxim, he tells us that sense, imagination, and pure intellection, are only different modes of perceiving, and, so the maxim was understood by all his followers. J The learned Dr Cudworth seems also to have adopted this principle : — " The cri- terion of true knowledge, says he, is only to be looked for in our knowledge and con- ceptions themselves : for the entity of all theoretical truth is nothing else but clear intelligibility, and whatever is clearly con- ceived is an entity and a truth ; but that which is false, divine power itself cannot make it to be clearly and distinctly under- stood. [400] A falsehood can never be clearly conceived or apprehended to be true." — " Eternal and Immutable Mora- lity," p. 172, &c. This Cartesian maxim seems to me to have led the way to that now under con- sideration, which seems to have been adopted as the proper correction of the former. When the authority of Des Cartes declined, men began to seeithat we may clearly and distinctly conceive what is not true, but * This was more a question with the Greek ptailo. sophers than with the schoolmen H. f In this .he proposed nothing new. -H. i That is, in Des Cartes' signification of the word, different modes of being conscioMs. See above.— H. [398-. 00' chap, in.] MISTAKES CONCERNING CONCEPTION. 377 thought, that our conception, though not in all cases a test of truth, might be a test of possibility.* This indeed seems to be a necessary con- sequence of the received doctrine of ideas ; it being evident that there can be no dis- tinct image, either in the mind or anywhere else, of that which ie impossible. -f The ambiguity of the word conceive, which we observed, Essay I. chap* 1, and the com- mon phraseology of saying we cannot con- ceive such a thing, when we would signify that we think it impossible, might likewise contribute to the reception of this doctrine. But, whatever was the origin of this opinion, it seems to prevail universally, and to be received as a maxim. " The bare having an idea of the propo- sition proves the thing not to be impossible ; for of an impossible proposition there can be no idea." — Da Samuel Clarke. "Of that which neither does nor can exist we can have no idea." — Lor© Bolinu- B HO ICE. "The measure of impossibility t©> us is iuconceivableness, that of which we can have no idea, but that reflecting upon it, it appears to be nothing, we pronounce to be impossible."— Abkrnethy. [401] " In every idea is implied the possibility of the existence of its object, nothing being clearer than that there can be no idea of an impossibility, or conception of what can- not exist." — Dr Price- " Impossible est cujus nullam notionem formare possumus ; possibile e contra, cui aliqua respondet notio." — Wolfii Ontolo- uia.J " It is an established maxim in metaphy- sics, that whatever the mind conceives, in- cludes the idea of possible existence, or, in other words, that nothing we imagine is absolutely impossible."—!). Hume. It were easy to muster up many other respectable authorities for this maxim, and I have never found one that called it in question. If the maxim be true in the extent which * That is, of logical possibility— the absence of con- tradiction.— H. + This is rather a strained inference.— ! I. ? These are not exactly Wolfs explosions. See ■• Ontologia," $§ 1()2, 103; " Philosophia nationalist' ( § h&i, 528. The fame doctrine is held by Tschirn- hauseu and others. In so far, however, as it is said that inconceivability is the criterion of impossibility, it is manifestly erroneous. Of many contradictories, we-are able to conceive neither; but, by the law of thaughtt called that of Excluded Middle, one ot two rontradictories must be admitted — must be true. For example, we can neiiher conceive, on the one hand, an ultimate minimum of space or of time; nor ran we, on the o her, conceive their infinite divisibi. lity. In like manner, we canno' conceive the absu- Uite commencement of time or the utmost limit of space, And are yet equally unable to conceive them without any commencement or limit. Theabsui others to be impossible, which, without oi demonstration, would not have been be- tg lieved. Yet I have never found that any j B mathematician has attempted to prove a tr thing to be possible, because it can be con- *; ceived ; or impossible, because it cannot be >. conceived. * Why is not this maxim applied In, to determine whether it is possible to square % the circle ? a point about which very emi-ij,,, nent mathematicians have differed. It isy easy to conceive that, in the infinite series u'., ot numbers, and intermediate fractions, it, some one number, integral or fractional**; may bear the same ratio to another, as tha side of a square bears to its diagonal -\ yet w tim« A df ^l et 1^'-' m f " rt ' f0Unded °" "'"■ intuit t.ons of space-that is, in common lanauace. on ouiV conceptions of space and its relations.'!? h" 60 ' °" ' t We are able tn conceive nothing infinite- andwdlw* .-avTOHw*-, but we cannot cancel,", ,. .„,'""? £\ r tmaome, t he possibility in qucstion.-H. ' ™^ [403, 4.04.1S, < chap..iv.J OF THE TRAIN OF THOUGHT IN THE MIND. U7!> however conceivable this maybe, it maybe demonstrated to be impossible. 4. Mathematicians often require us to conceive things that are impossible, in order to prove them to be so. This is the case in all their demonstrations ad absurdum. Conceive, says Euclid, a right line drawn from one point of the circumference of a circle to another, to fall without the circle :* 1 conceive this— I reason from it, until I come to a consequence that is manifestly absurd ; and from thence conclude that the thing which I conceived is impossible. Having said so much to shew that our power of conceiving a proposition is no criterion of its possibility or impossibility, I shall add a few observations on the extent of our knowledge of this kind. 1. There are many propositions which, by the faculties God has given us, we judge to be necessary, as well as true. AH mathematical propositions are of this kind, and many others. The contradictories of such propositions must be impossible. Our knowledge, therefore, of what is impossible, must, at least, be as extensive as our know- ledge of necessary truth. 2. By our senses, by memory, by testi- ■niony, and by other means, we know many things to be true which do not appear to be necessary. But whatever is true is pos- sible. Our knowledge, therefore, of what is po-sible must, at least, extend as far as our knowledge of truth. [405] 3. If a man pretends to determine the possibility or impossibility of things beyond these limits, let him bring proof. I do not say that no such proof can be brought. It has been brought in many cases, particu- larly in mathematics. But I say that his lieing able to conceive a thing, is no proof that it is possible. + Mathematics afford many instances of impossibilities in the nature of things, which no man would have believed if they had not been strictly de- monstrated. Perhaps, if we were able to reason demonstratively in other subjects, to aa great extent as in mathematics, wo might find many things to be impossible, which we conclude without hesitation, to be pos- sible. It is possible, you say, that God might have made an universe of sensible and ra- tional creatures, into which neither natural nor moral evil should ever enter. It may be so, for what I know. But how do you know that it is possible ? That you can lijpnceive it, I grant; but this is no proof. F* c.,.-i:,i j,,',., not ' equire us to conceive or imagine L * F.U( -lid dots "°' |t £ The proposition to which iny such imposs w ' y 8M01ld of the third Hook of »id must relents im JjieElements — H- ^t it h really possible, but that I,*. Not, certainly. me _ t „ i„ T „| TC , n0 ro „. It» probhwn 'S""^ n | aw ,f thought. This latter fepSimy-o".- in .pusHon.-H. fi05, 406] I cannot admit, as an argument, or even as a pressing difficulty, what is grounded on the supposition that such a thing is possible, when there is no goud evidence that it is possible, and, for anything we know, it may. in the nature of things, be impossible. CHAPTER IV. OF THE TRAIN OF THOUGHT IN THE MIND. Every man is conscious of a succession of thoughts which pass in his mind while he is awake, even when they are not excited by external objects. [40C] The mind, on this account, may be com- pared to liquor in the state of fermentation. When it is not in this state, being once at rest, it remains at rest, until it is moved by some external impulse. But, in the state of fermentation, it has some cause of motion in itself, which, even when there is no im- pulse from without, suffers it not to be at rest a moment, but produces a constant motion and ebullition, while it continues to ferment. There is surely no similitude between motion and thought ; but there is an analogy, so obvious to all men, that the same words are often applied to both ; and many modi- fications of thought have no name but such as is borrowed from the modifications of^ motion. Many thoughts are excited by the senses. The causes or occasions of these may be considered as external. But, when sueh external causes do not operate upon us, we continue to think from some internal cause. From the constitution of the mind itself there isaconstant ebullition of thought, a constant intestine motion ; not only of thoughts barely speculative, but of senti- ments,passions, and affections, which attend them. This continued succession of thought has, by modern philosophers, been called the imagination." I think it was formerly called the fancy, or the phaiUm-y.f If the old name be laid aside, it were to be wished that it had got a name less ambiguous than that of imagination, a name which had two cr three meanings besides. It is often called the train of ideas. This may lead one to think that it is a train of bare conceptions ; but this would surely l.e a mistake. It is made up of many other operations of mind, as well as of concep- tions, or ideas. * By some onlv, and that improperly. — H. t '1 he I arm I'mciginalifi, with its modifications in the vulgar languages, was employed both in ancient and modem times to express what the Greeks -deno- minated $ posititious Pythagorean treatises are genuine. — tl. 406 ON THE INTELLECTUAL POWERS. essay v. Porphyry has given us a very distinct treatise upon these, as an introduction to Aristotle's categories. But he has omitted the intricate metaphysical questions that were agitated about their nature : such aa, whether genera and species do really exist in nature, or whether they are only con- ceptions of the human mind. If they exist in nature, whether they are corporeal or incorporeal ; and whether they are inherent in the objects of sense, or disjoined from them. These questions, he tells us, for brevity's sake, he omits, because they are very profound, and require accurate discus- sion. It is probable that these questions exercised the wits of the philosophers till about the twelfth century. [478] About that time, Roscelinus or Rusce- linus, the master of the famous Abelard, introduced a new doctrine — that there is nothing universal but words or names. For this, and other heresies, he was much persecuted. However, by his eloquence and abilities, and those of his disciple Abe- lard, the doctrine spread, and those who followed it wore called Nominalists. * His antagonists, who held that there are things that are really universal, were called Realists. The scholastic philosophers, from the be- ginning of the twelfth century, were divided into these two sects. Some few took a middle road between the contending parties. That universality which the Realists held to be in things themselves, Nominalists in names only, they held to be neither in things nor in names only, but in our conceptions. On this account they were called Concep- tualists : but, being exposed to the batteries of both the opposite parties, they made no great figure, f When the sect of Nominalists was like to expire, it received new life and spirit from Occam, the disciple of Scotus, in the fourteenth century. Then the dispute about universals, a parte rei, was revived with the greatest animosity in the schools of Britain, France, and Germany, and carried on, not by arguments only, but by bitter reproaches, blows, and bloody affrays, until the doctrines of Luther and the other Re- formers turned the attention of the learned world to more important subjects. After the revival of learning, Mr Hobbes adopted the opinion of the Nominalists. $ * Abelard was not a Nominalist like Roscelinus ; but held a doctrine, intermediate between absolute Nominalism and Realism, corresponding to the opinion since called Conceptualism. A flood of light has been thrown upon Abelard's doctrines, by M. Cousin's introduction to his recent publication of the unedited works of that illustrious thinker H. t The later Nominalists, of the school of Occam, were really Conceptualists in our sense of the term. — H. % Hobbes is justly said by Leibnitz to have been >7wu Nowinattbus vominalior. Tlim were really Conceptualists H " Human Nature," chap 5, § 6 — " It is plain, therefore," says he, "thatthereis no- thing universal but names." And in his " Leviathan," part i. chap 4, " There being nothing universal but names, proper names bring to mind one thing only ; universals recall any one of many." Mr Locke, according to the division he- fore mentioned, I think, may be accounted a Conceptualist. He does not maintain that there are things that are universal; but that we have general or universal ideas which we form by abstraction ; and this power of forming abstract and general ideas, he conceives to be that which makes the chief distinction in point of understanding, between men and brutes. [479] Mr Locke's doctrine about abstraction has been combated by two very powerful antagonists, Bishop Berkeley and Mr Hume, who have taken up the opinion of the Nom- inalists. The former thinks, " That the opinion that the mind hath a power of form- ing abstract ideas or notions of things, has had a chief part in rendering speculation intricate and perplexed, and has occasioned innumerable errors and difficulties in almost all parts of knowledge." That " abstract ideas are like a fine and subtile net, which has miserably perplexed and entangled tha minds of men, with this peculiar circum- stance, that by how much the finer and more curious was the wit of any man, by so much the deeper was he like to be en- snared, and faster held therein." That, " among all the false principles that have obtained in the world, there is none hath a more wide influence over the thoughts of speculative men, than this of abstract gene- ral ideas." The good bishop, therefore, in twenty- four pages of the introduction to his " Prin- ciples of Human Knowledge," encounters this principle with a zeal proportioned to his apprehension of its malignant and ex- tensive influence. That the zeal of the sceptical philosopher against abstract ideas was almost equal to that of the bishop, appears from his words, " Treatise of Human Nature," Book I. part i. § 7 : — " A very material question has been started concerning abstract or general ideas — whether they be general oi particular, |in the mind's conception of them. A great philosopher" (he means Dr Berke- ley) " has disputed the received opinion in this particular, and has asserted that all general ideas are nothing but particular ones annexed to a certain term, which gives them a more extensive signification, and makes them recall, upon occasion, other individuals which are similar to them. As I look upon this to be one of the greatest and most valuable discoveries that have been made of late years in the republic of letters, I f478, 479"| AP. VI.] OPINIONS ABOUT UNIVERSALE 407 ill here endeavour to confirm it by some piments, which, I hope, will put it beyond doubt and controversy." [480] I shall make an end of this subject, with ne reflections on what has been said upon by these two eminent philosophers. 1. First, I apprehend that we cannot, th propriety, be said to have abstract and aeral ideas, either in the popular or in the ilosophical sense of that word. In the pular sense, an idea is a thought ; it is 3 act of the mind in thinking, or in con- iving any object. This act of the mind always an individual act, and, therefore, ere can be no general idea in this sense, the philosophical sense, an idea is an age in the mind, or in the brain, which, Mr Locke's system, is the immediate ob- it of thought ; in the system of Berkeley d Hume, the only object of thought. I lieve there are no ideas of this kind, and, erefore, no abstract general ideas. In- ed, if there were really such images in a mind or in the brain, they could not general, because everything that really ists is an individual. Universals are ither acts of the mind, nor images in the ind. As, therefore, there are no general ideas either of the senses in which the word ;a is used by the moderns, Berkeley and ume have, in this question, an advantage er Mr Locke ; and their arguments against m are good ad hominem. They saw rther than he did into the just conse- ences of the hypothesis concerning ideas, lich was common to them and to him ; d they reasoned justly from this hypo- esis when they concluded from it, that ere is neither a material world, nor any ch power in the human mind as that of straction. [481] A triangle, in general, or any other uni- rsal, might be called an idea by a Plato- 3t; but, in the style of modern philo- phy, it is not an idea, nor do we ever cribe to ideas the properties of triangles, is never said of any idea, that it has ree sides and three angles. We do not eak of equilateral, isosceles, or scalene 3as, nor of right-angled, acute-angled, or tuse-angled ideas. And, if these attri- tes do not belong to ideas, it follows, cessarily, that a triangle is not an idea, le same reasoning may be applied to ery other universal. Ideas are said to have a real existence in e mind, at least while we think of them ; t universals have no real existence, hen we ascribe existence to them, it is t an existence in time or place, but exist- ce in some individual subject ; and this istence means no more but that they are ily attributes of such a subject. Their istence is nothing but predicability, or the -80-482J capacity of being attributed to a subject. The name of predicables, which was given them in ancient philosophy, is that which most properly expresses their nature. 2. I think it must be granted, in the second place, that universals cannot be the objects of imagination, when we take that word in its strict and proper sense. " I find," says Berkeley, " I have a faculty of imagining or representing to myself the ideas of those particular things I have per- ceived, and of variously compounding and dividing them. I can imagine a man with two heads, or the upper parts of a man joined to the body of a horse. I can imagine the hand, the eye, the nose, each by itself, abstracted or separated from the rest of the body. But then, whatever hand or eye I imagine, it must have some particular shape or colour. Likewise, the idea of a man that I frame to myself must be either of a white, or a black, or a tawny ; a straight or a crooked ; a tall, or a low, or a middle-sized man." I believe every man will find in himself what this ingenious author found — that he cannot imagine a man without colour, or stature, or shape. [482] Imagination, as we before observed, pro- perly signifies a conception of the appear' ance an object would make to the eye it actually seen." An universal is not an object of any external sense, and therefore cannot be imagined ; but it may be dis- tinctly conceived. When Mr Pope says, " The proper study of mankind is man," i conceive his meaning distinctly, though I neither imagine a black or a white, a crooked or a straight man. The distinction between conception and imagination is real, though it be too often overlooked, and the words taken to be synonimous. I can con- ceive a thing that is impossible, ■(■ but I cannot distinctly imagine a thing that is impossible. I can conceive a proposition or a " demonstration, but I cannot imagine either. I can conceive understanding and will, virtue and vice, and other attributes of mind, but I cannot imagine them. In like manner, I can distinctly conceive uni- versals, but I cannot imagine them. J As to the manner how we conceive uni> versals, I confess my ignorance. I know not how I hear, or see, or remember, and as little do I know how I conceive things that have no existence. In all our original * See above, p. 366, a, note.— H. t See above, p. 377, b, note.— H. X Imagination and Conception are distinguished, but tbe latter ought not to be used in the vague and extensive signification of Reid. The discrimination in question is best made in the German language of philosophy, where the terms Begriffe (Conceptions) are strongly contrasted with Amchauungen (Intui- tions), Bilden (Images), &c See above, p. 360, a, note I ; p. 365, b, note -f. The reader may compare Stewart's " Elements," I. p. 196 H. 403 ON THJE INTELLECTUAL POWERS. [essay faculties, the fabric and manner of operation is, I apprehend, beyond our comprehension, and perhaps is perfectly understood by him only who made them. But we ought not to deny a fact of which we are conscious, though we know not how it is brought about. And I think we may be certain that universals are not conceived by means of images of them in our minds, because there can be no image of an uni- versal. 3. It seems to me, that on this question Mr Locke and his two antagonists have divided the truth between them. He saw very clearly, that the power of forming ab- stract and general conceptions is one of the most distinguishing powers of the human mind, and puts a specific difference between man and the brute creation. But he did not see that this power is perfectly irrecon- cileable to his doctrine concerning ideas. [483] His opponents saw this inconsistency ; but, instead of rejecting the hypothesis of ideas, they explain away the power of ab- straction, and leave no specific distinction between the human understanding and that of brutes. 4. Berkeley,* in his reasoning against abstract general ideas, seems unwillingly or unwarily to grant all that is necessary to support abstract and general concep- tions. *' A man," he says, " may consider a figure merely as triangular, without attend- ing to the particular qualities of the angles, or relations of the sides- So far he may abstract. But this will never prove that he can frame an abstract general inconsist- ent idea of a triangle." If a man may consider a figure merely as triangular, he must have some concep- tion of this object of his consideration ; for no man can consider a thing which he does not conceive. He has a conception, there- fore, of a triangular figure, merely as such. I know no more that is meant by an abstract general conception of a triangle. He that considers a figure merely as tri- angular, must understand what is meant by the word triangular. If, to the conception he joins to this word, he adds any particu- lar quality of angles or relation of sides, he misunderstands it, and does not consider the figure merely as triangular. Whence, I think, it is evident, that he who considers a figure merely as triangular must have the conception of a triangle, abstracting from any quality of angles or relation of sides. The Bishop, in like manner, grants, " That we may consider Peter so far forth as man, or so far forth as animal, without * On Reid's criticism of Berkeley, see Stewart, [Elements, II. p. 110, tq )— H. framing the forementioned abstract idea, in as much as all that is perceived is not considered." It may here be observed, that he who considers Peter so far forth as man, or so far forth as animal, must con- ceive the meaning of those abstract genera words man and animal, and he who con- ceives the meaning of them has an abstract general conception. [484] From these concessions, one would be apt to conclude that the Bishop thinks that we can abstract, but that we cannot frame abstract ideas ; and in this I should agree with him. But I cannot reconcile his con- cessions with the general principle he lavs down before. " To be plain," says he, "I deny that I can abstract one from another, or conceive separately those qualities which it is impossible should exist so separated." This appears to me inconsistent with the concessions above mentioned, and incon- sistent with experience. If we can consider a figure merely as triangular, without attending to the parti- cular quality of the angles or relation of the sides, this, I think, is conceiving separately things which cannot exist so separated: for surely a triangle cannot exist without a particular quality of angles and relation of sides. And it is well known, from ex- perience, that a man may have a distinct conception of a triangle, without having any conception or knowledge of many of the properties without which a triangle cannot exist. Let us next consider the Bishop's notion of generalising.* He does not absolutely deny that there are general ideas, but only that there are abstract general ideas. " An idea," he says, " which, considered in it- self, is particular, becomes general, by be- ing made to represent or stand for all other particular ideas of the same sort. To make this plain by an example : Suppose a geo- metrician is demonstrating the method of cutting a line in two equal parts. He draws, for instance, a black line, of an inch in length. This, which is in itself a parti- cular line, is, nevertheless, with regard to its signification, general ; since, as it is there used, it represents all particular lines whatsoever ; so that what is demonstrated of it, is demonstrated of all lines, or, in other words, of a line in general. And as that particular line becomes general by be- ing made a sign, so the name line, which, taken absolutely, is particular, by being a sign, is made general." [485] Here I observe, that when a particular idea is made a sign to represent and stand for all of a sort, this supposes a distinction of things into sorts or species. To be of a sort implies having those attributes which * See Stewart, (Elements, II p. 1250— H. [ 1.83-485] c.hm: VI J OPINIONS ABOUT UNlVERSALS. 409 characterise the sort, and are common to all the individuals that belong to it. There cannot, therefore, be a sort without general attributes, nor can there be any conception of a sort without a conception of those general attributes which distinguish it. The conception of a sort, therefore, is an ab- stract general conception. The particular idea cannot surely be made a sign of a thing of which we have no con- ception. I do not say that you must have an idea of the sort, but surely you ought to understand or conceive what it means, when you make a particular idea a repre- sentative of it ; otherwise your particular idea represents, you know not what. When I demonstrate any general pro- perty of a triangle, such as, that the three angles are equal to two right angles, I must understand or conceive distinctly what is common to all triangles. I must distinguish the common attributes of all triangles from those wherein particular triangles may differ. And, if I conceive distinctly what is common to all triangles, without confounding it with what is not so, this is to form a general con- ception of a triangle. And without this, it is impossible to know that the demonstra- tion extends to all triangles. The Bishop takes particular notice of this argument, and makes this answer to it : — •* Though the idea I have in view, whilst I make the demonstration, be, for instance, that of an isosceles rectangular triangle, whose sides are of a determinate length, I may nevertheless be certain that it extends to all other rectilinear triangles, of what sort or bigness soever; and that because neither the right angle, nor the equality or determinate length of the sides, are at all concerned in the demonstration." [486] But, if he do not, in the idea he has in view, clearly distinguish what is common to all triangles from what is not, it would be impossible to discern whether something that is not common be concerned in the demonstratien or not. In order, therefore, to perceive that the demonstration extends to all triangles, it is necessary to have a distinct conception of what is common to all triangles, excluding from that concep- tion all that is not common- And this is all I understand by an abstract general conception of a triangle. Berkeley catches an advantage to his side of the question, from what Mr Locke ex- presses (too strongly indeed) of the difficulty of framing abstract general ideas, and the pains and skill necessary for that purpose. From which the Bishop infers, that a thing so difficult cannot be necessary for com- munication by language, which is so easy and familiar to all sorts of men. There may be some abstract and general conceptions that are difficult, or even be- C486-488] yond the reach of persons of weak under- standing ; but there are innumerable which are not beyond the reach of children. It is impossible to learn language without acquiring general conceptions; for there cannot be a single sentence without them. I believe the forming these, and being able to articulate the sounds of language, make up the whole difficulty that children find in learning language at first. But this difficulty, we see, they are able to overcome so early as not to remember the pains it cost them. They have the strongest inducement to exert all their labour and skill, in order to understand and to be understood ; and they no doubt do so. [487] The labour of forming abstract notions, is the labour of learning to speak, and to understand what is spoken. As the words of every language, excepting a few proper names, are general words, the minds of children are furnished with general con- ceptions, in proportion as they learn the meaning of general words. I believe most men have hardly any general notions but those which are expressed by the general words they hear and use in conversation. The meaning of some of these is learned by a definition, which at once conveys a distinct and accurate general conception. The meaning of other general words we collect, by a kind of induction, from the way in which we see them used on various occasions by those who understand the language. Of these our conception is often less distinct, and in different persons is perhaps not perfectly the same. " Is it not a hard thing," says the Bishop, " that a couple of children cannot prate to- gether of their sugar-plumbs and rattles, and the rest of their little trinkets, till they have first tacked together numberless in- consistencies, and so formed in their minds abstract general ideas, and annexed them to every common name they make use of?" However hard a thing it may be, it is an evident truth, that a couple of children, even about their sugar- plumbs and their rattles, cannot prate so as to understand and be understood, until they have learned to conceive the meaning of many general words — and this, I think, is to have general conceptions. 5. Having considered the sentiments of Bishop Berkeley on this subject, let us next attend to those of Mr Hume, as they are expressed Part I. § 7, " Treatise of Human Nature." He agrees perfectly with the Bishop, " That all general ideas are nothing but particular ones annexed to a certain term, which gives them a more extensive signification, and makes them recall, upon occasion, other individuals which are similar to them. [488] A particular 410 ON THE INTELLECTUAL POWERS. [essay v. idea becomes general, by being annexed to a general term ; that is, to a term, which, from a customary conjunction, has a rela- tion to many other particular ideas, and readily recalls them in the imagination. Abstract ideas are therefore in themselves individual, however they may become general in their representation. The image in the mind is only that of a particular object, though the application of it in our reason- ing be the same as if it was universal." Although Mr Hume looks upon this to be one of the greatest and most valuable discoveries that has been made of late years in the republic of letters, it appears to be no other than the opinion of the nominal- ists, about which so much dispute was held from the beginning of the twelfth century down to the Reformation, and which was afterwards supported by Mr Hobbes. I shall briefly consider the argu- ments by which Mr Hume hopes to have put it beyond all doubt and controversy. First, He endeavours to prove, by three arguments, that it is utterly impossible to conceive any quantity or quality, without forming a precise notion of its degrees; This is indeed a great undertaking ; but, if he could prove it, it is not sufficient for his purpose — for two reasons. First, Because there are many attributes of things, besides quantity and quality ; and it is incumbent upon him to prove that it is impossible to conceive any attribute, without forming a precise notion of its degree. Each of the ten categories of Aristotle is a genus, and may be an attri- bute. And, if he should prove of two of them — to wit, quantity and quality — that there can be no general conception of them ; there remain eight behind, of which this must be proved. [489J The other reason is, because, though it were impossible to conceive any quantity or quality, without forming a precise notion of its degree, it does not follow that it is impossible to have a general conception even of quantity and quality. The con- ception of a pound troy is the conception of a quantity, and of the precise degree of that quantity ; but it is an abstract general conception notwithstanding, because it may be the attribute of many individual bodies, and of many kinds of bodies. He ought, therefore, to have proved that we cannot conceive quantity or quality, or any other attribute, without joining it inseparably to some individual subject. This remains to be proved, which will be found no easy matter. For instance, I conceive what is meant by a Japanese as distinctly as what is meant by an English- man or a Frenchman. It is true, a Japan- ese is neither quantity nor quality, but it is an attribute common to every individual of a populous nation. I never saw an in- dividual of that nation ; and, if I can trust my consciousness, the general term does not lead me to imagine one individual of the sort as a representative of all others. Though Mr Hume, therefore, undertakes much, yet, if he could prove all he under- takes to prove, it would by no means be sufficient to shew that we have no abstract general conceptions. Passing this, let us attend to his argu- ments for proving this extraordinary posi- tion, that it is impossible to conceive any quantity or quality, without forming a pre- cise notion of its degree. The first argument is, that it is impossi- ble to distinguish things that are not ac- tually separable. " The precise length of a line is not different or distinguishable from the line." [490] I have before endeavoured to shew, that things inseparable in their nature may be- distinguished in our conception. And we need go no farther to be convinced of this, than the instance here brought to prove the contrary. The precise length of a line, he says, is not distinguishable from the line. When I say, This is a line, I say and mean one thing. When I say, It is a line of three inches, I say and mean another thing. If this be not to distinguish the precise length of the line from the line, I know not what it is to distinguish. Second argument " Every object of sense — that is, every impression — is an in- dividual, having its determinate degrees of quantity and quality. But whatever is true of the impression is true of the idea, as they differ in nothing but their strength and vivacity." The conclusion in this argument is, in- deed, justly drawn from the premises. If it be true that ideas differ in nothing from objects of sense, but in strength and viva- city, as it must be granted that all the ob- jects of sense are individuals, it will cer- tainly follow that all ideas are individuals. Granting, therefore, the justness of this conclusion, I beg leave to draw two other conclusions from the same premises, which will follow no less necessarily. First, If ideas differ from the objects of sense only in strength and vivacity, it will follow, that the idea of a lion is a lion of less strength and vivacity. And hence may arise a very important question, Whether the idea of a lion may not tear in pieces, and devour the ideas of sheep, oxen, and horses, and even of men, women, and children ? Secondly, If ideas differ only in strength and vivacity from the objects of sense, it will follow that objects merely conceived, are not ideas ; for such objects differ from the objects of sense in respects of a very [489. 490" CHAP. VI.3 OPINIONS ABOUT UNIVERSALS. 411 different nature from strength and vivacity. [49 1 ] Every object of sense must have a real existence, and time and place. But things merely conceived may neither have existence, nor time nor place ; and, there- fore, though there should be no abstract ideas, it does not follow that things abstract and general may not be conceived. The third argument is this : — " It is a principle generally received in philosophy, that everything in nature is individual ; and that it is utterly absurd to suppose a tri- angle really existent which has no precise proportion of sides and angles. If this, therefore, be absurd in fact and reality, it must be absurd in idea, since nothing of which we can form a clear and distinct idea is absurd or impossible." I acknowledge it to be impossible that a triangle should really exist which has no precise proportion of sides and angles ; and impossible that any being should exist which is not an individual being ; for, I think, a being and an individual being mean the same thing : but that there can be no attributes common to many indivi- duals I do not acknowledge. Thus, to many figures that really exist it may be common that they are triangles ; and to many bodies that exist it may be common that they are fluid. Triangle and fluid are not beings, thgy are attributes of beings. As to the principle here assumed, that nothing of which we can form a clear and distinct idea is absurd or impossible, I refer to what was said upon it, chap. 3, Essay 1 V. It is evident that, in every mathema- tical demonstration, ad absurdum, of which kind almost one-half of mathematics con- sists, we are required to suppose, and, con- sequently, to conceive, a thing that is im- possible. From that supposition we reason, until we come to a conclusion that is not only impossible but absurd. From this we infer that the proposition supposed at first is impossible, and, therefore, that its con- tradictory is true. [492] As this is the nature of all demonstra- tions, ad a'osurdum, it is evident, (I do not say that we can have a clear and distinct idea,) but that we can clearly and distinctly conceive things impossible. The rest of Mr Hume's discourse upon this subject is employed in explaining how an individual idea, annexed to a general term, may serve all the purposes in reason- ing which have been ascribed to abstract general ideas. " When we have found a resemblance among several objects that often occur to us, we apply the same name to all of them, whatever differences we may observe in the degrees of their quantity and quality, and whatever other differences may appear among them. After we have acquired a [>91-493] custom of this kind, the hearing of that name revives the idea of one of these ob- jects, and makes the imagination conceive it, with all its circumstances and propor- tions." But, along with this idea, there is a readiness to survey any other of the indi- viduals to which the name belongs, and to observe that no conclusion be formed con- trary to any of them. If any such conclu- sion is formed, those individual ideas which contradict it immediately crowd in upon us, and make us perceive the falsehood of the proposition. If the mind suggests not al- ways these ideas upon occasion, it proceeds from some imperfection in its faculties ; and such a one as is often the source of false reasoning and sophistry. This is, in substance, the way in which he accounts for what he calls " the fore- going paradox, that some ideas are parti- cular in their nature, but general in their representation." Upon this account I shall make some remarks. [493] 1. He allows that we find a resemblance among several objects, and such a resem- blance as leads us to apply the same name to all of them. This concession is suffi- cient to shew that we have general concep- tions. There can be no resemblance in objects that have " no common attribute ; and, if there be attributes belonging in com- mon to several objects, and in man a fa- culty to observe and conceive these, and to give names to them, this is to have general conceptions. I believe, indeed, we may have an indis- tinct perception of resemblance without knowing wherein it lies. Thus, I may see a resemblance between one face and an- other, when I cannot distinctly say in what feature they resemble ; but, by analysing the two faces, and comparing feature with feature, I may form a distinct notion of that which is common to both. A painter, being accustomed to an analysis of this kind, would have formed a distinct notion of this resemblance at first sight ; to another man it may require some attention. There is, therefore, an indistinct notion of resemblance when we compare the obj ects only in gross : and this I believe brute ani- mals may have. There is also a distinct notion of resemblance when we analyse the objects into their different attributes, and perceive them to agree in some while they differ in others. It is in this case only that we give a name to the attributes wherein they agree, which must be a common name, because the thing signified by it is common. Thus, when I compare cubes of different matter, I perceive them to have this attri- bute in common, that they are compre- hended under six equal squares, and this attribute only is signified by applying the name of cube to them all. When I com- 4.2 ON THE INTELLECTUAL POWERS. [essaV V*. pare clean linen with snow, I perceive them to agree in colour ; and when I apply the name of white to both, this name signifies neither snow nor clean linen, but the attri- bute which is common to both. 2. The author says, that when we have found a resemblance among several objects, we apply the same name to all of them. [494] It must here be observed, that there are two kinds of names which the author seems to confound, though they are very different in nature, and in the power they have in language. There are proper names, and there are common names or appellatives. The first are the names of individuals. The same proper name is never applied to several individuals on account of their simi- litude, because the very intention of a pro- per name is to distinguish one individual from all others ; and hence it is a maxim in grammar that proper names have no plural number. A proper name signifies nothing but the individual whose name it is ; and, when we apply it to the individual, we neither affirm nor deny anything con- cerning him. A common name or appellative is not the name of any individual, but a general term, signifying something that is or may be common to several individuals. Common names, therefore, signify common attri- butes. Thus, when I apply the name of son or brother to several persons, this sig- nifies and affirms that this attribute is common to all of them. From this, it is evident that the apply- ing the same name to several individuals on account of their resemblance, can, in consistence with grammar and common sense, mean nothing else than the express- ing, by a general term, something that is common to those individuals, and which, therefore, may be truly affirmed of them all. 3. The author says, " It is certain that we form the idea of individuals whenever we use any general term. The word raises up an individual idea, and makes the ima- gination conceive it, with all its particular circumstances and proportions." This fact he takes a great deal of pains to account for, from the effect of custom. [495] But the fact should be ascertained before we take pains to account for it. I can see no reason to believe the fact ; and I think a farmer can talk of his sheep and his black cattle, without conceiving, in his imagina- tion, one individual, with all its circum- stances and proportions. If this be true, the whole of his theory of general ideas falls to the ground. To me it appears, that when a general term is well understood, it is only by accident if it suggest some indi- vidual of the kind ; but this effect is by no means constant. I understand perfectly what mathemati- cians call a line of the fifth order ; yet I never conceived in my imagination any one of the kind in all its circumstances and pro- portions. Sir Isaac Newton first formed a distinct general conception of lines of the third order ; and afterwards, by great labour and deep penetration, found out and de- scribed the particular species comprehended under that general term. According to Mr Hume's theory, he must first have been acquainted with the particulars, and then have learned by custom to apply one general name to all of them. The author observes, " That the idea of an equilateral triangle of an inch perpen- dicular, may serve us in talking of a figure, a rectilinear figure, a regular figure, a tri- angle, and an equilateral triangle. 1 ' I answer, the man that uses these general terms either understands their meaning, or he does not. If he does not understand their meaning, all his talk about them will be found only without sense, and the par- ticular idea mentioned cannot enable him to speak of them with understanding. If he understands the meaning^of the general terms, he will find no use for the particular idea, 4. He tells us gravely, " That in a globe of white marble the figure and the colour are undistinguishable, and are in effect the same." [496] How foolish have mankind been to give different names, in all ages andin all languages, to things undistinguish- able, and hi effect the same ? Henceforth, in all books of science and of entertainment, we may substitute figure for colour, and colour for figure. By this we shall make numberless curious discoveries, without danger of error." [497] * The whole controversy of Nominalism and Con. ceptualism is founded on the ambiguity of the terms employed. The opposite parties are substantially at one. Had our British philosophers been aware of the Leibnitzian distinction of Intuitive and Symboli- cal knowledge ; and had we, like the Germans, different terms, like Beariff uniAmchauung, to de. note different kinds of thought, there would have been as little difference of opinion in regard to the nature of general notions in this country as in the Empire. v\ ith us, Idea, Notion, Conception, He are confounded, or applied by different philosophers in different senses. I must put the reader on his guard against Dr Thomas Brown's speculations on this subject. His own doctrine of universals, in so far as it is peculiar, is self-contradictory; and nothing can be more erroneous than his statement of the doc- trine held by others, especially by the Nominalists. — H. [494-4971 r.uAf. i.] OF JUDGMENT IN UENEIUL. 413 ESSAY VI. OF JUDGMENT CHAPTER I. OF JUDGMENT IN GENERAL. Judging is an operation of the mind so familiar to every man who hath understand- ing, and its name is so common and so well understood, that it needs no definition. As it is impossible by a definition to give a notion of colour to a man who never saw colours ; so it is impossible by any defini- tion to give a distinct notion of judgment to a man who has not often judged, and who is not capable of reflecting attentively upon this act of his mind. The best use of a de- finition is to prompt him to that reflection ; and without it the best definition will be apt to mislead him. The definition commonly given of judg- ment, by the more ancient writers in logic, was, that it is an act of the mind, whereby one- thing is affirmed or denied of another. I believe this is as good a definition of it as can be given. Why I prefer it to some later definitions, will afterwards appear. Without pretending to give any other, I shall make two remarks upon it, and then offer some general observations on this subject. [498] 1. It is true that it is by affirmation or denial that we express our judgments ; but there may be judgment which is not ex- pressed. It is a solitary act of the mind, and the expression of it by affirmation or denial is not at all essential to it. It may be tacit, and not expressed. Nay, it is well known that men may judge contrary to what they affirm or deny ; the definition therefore must be understood of mental af- firmation or denial, which indeed is only another name for judgment. 2. Affirmation and denial is very often the expression of testimony, which is a dif- ferent act of the mind, and ought to be distinguished from judgment. A judge asks of a witness what he knows of such a matter to which he was an eye or ear-witness. He answers, by affirming or denying something But his answer does not express his judgment; it is his testimony. Again, I ask a man his opinion in a matter of science or of criticism. His answer is not testimony ; it is the expres- sion of his judgment. Testimony is a social act, and it is essen [4.98, 499] tial to it to be expressed by words or signs. A tacit testimony is a contradiction : but there is no contradiction in a tacit judgment ; it is complete without being expressed. In testimony a man pledges his veracity for what he affirms ; so that a false testi- mony is a lie : but a wrong judgment is not a lie ; it is only an error. I believe, in all languages, testimony and judgment are expressed by the same form of speech. A proposition affirmative or negative, with a verb in what is called the indicative mood, expresses both. To dis- tinguish them by the form of speech, it would be necessary that verbs should have two indicative moods, one for testimony, and another to express judgment. [499] I know not that this is found in any lan- guage. And the reason is — not surely that the vulgar cannot distinguish the two, for every man knows the difference between a lie and an error of judgment — but that, from the matter and circumstances, we can easily see whether a man intends to give his tes- timony, or barely to express his judgment Although men must have judged in many cases before tribunals of justice were erected, yet it is very probable that there were tribunals before men began to specu- late about judgment, and that the word may be borrowed from the practice of tribunals. As a judge, after taking the proper evidence, passes sentence in a cause, and that sent- ence is called his judgment, so the mind, with regard to whatever is true or false, passes sentence, or determines according to the evidence that appears. Some kinds of evidence leave no room for doubt. Sent- ence is passed immediately, without seek- ing or hearing any contrary evidence, because the thing is certain and notorious. In other cases, there is room for weighing evidence on both sides, before sentence is passed. The analogy between a tribunal of justice, and this inward tribunal of the mind, is too obvious to escape the notice of any man who ever appeared before a judge. And it is probable that the word judgment, as well asmany other words we use in speak- ing of this operation of mind, are grounded on this analogy. Having premised these things, that it may be clearly understood what I mean by judgment, I proceed to make some general observations concerning it. 414 ON THE INTELLECTUAL POWERS. [E8SJ1V VJ, First, Judgment is an act of the mind, specifically different from simple apprehen- sion, or the bare conception of a thing. * It would be unnecessary to observe this, if some philosophers had not been led by their theories to a contrary opinion. [500] Although there can be no judgment with- out a conception of the things about which we j udge, yet conception may be without any judgment. -f Judgment can be expressed by a proposition only, and a proposition is a complete sentence ; but simple apprehen- sion may be expressed by a word or words, which make no complete sentence. When simple apprehension is employed about a proposition, every man knows that it is one thing to apprehend a proposition — that is, to conceive what it means — but it is quite another thing to judge it to be true or false. It is self-evident that every judgment must be either true or falser but simple apprehension, or conception, can neither be true nor false, as was shewn before. One judgment may be contradictory to another ; and it is impossible for a man to have two judgments at the same time, which he perceives to be contradictory. But con- tradictory propositions may be conceived^ at the same time without any difficulty. That the sun is greater than the earth, and that the sun is not greater than the earth, are contradictory propositions. He that apprehends the meaning of one, apprehends the meaning of both. But it is impossible for him to judge both to be true at the same time. He knows that, if the one is true, the other must be false. For these reasons, I hold it to be certain that judgment and simple apprehension are acts of the mind specifically different. Secondly, There are notions or ideas that ought to be referred to the faculty of judg- ment as their source ; because, if we had not that faculty, they could not enter into our minds; and to those that have that faculty, and are capable of reflecting upon its operations, they are obvious and familiar. Among these we may reckon the notion of judgment itself ; the notions of a propos- ition—of its subject, predicate, and copula ; of affirmation and negation, of true and false ; of knowledge, belief, disbelief, opi- nion, assent, evidence. From no source could we acquire these notions, but from reflecting upon our judgments. Eelations of things make one great class of our notions or ideas ; and we cannot have the idea of any relation without some exercise of judg- ment, as will appear afterwards. [501] Thirdly, In persons come to years of * Which, however, implies a judgment affirming ts subjective reality— an existentialjudgment.— H. t 6ee last note, and above, p. 243, a, note *, and n. 1 5, a, note f H. % See above, p. 377, b, note.— H understanding, judgment necessarily accom- panies all sensation, perception by the senses, consciousness, and memory, but not conception.* I restrict this to persons come to the years of understanding, because it may be a ques- tion, whether infants, in the first period of life, have any judgment or belief at all." The same question may be put with regard to brutes and some idiots. This question is foreign to the present subject ; and I say nothing here about it, but speak only of persons who have the exercise of judg- ment. In them it is evident that a man who feels pain, judges and believes that he is really pained. The man who perceives an object, believes that it exists, and is what he distinctly perceives it to be ; nor is it in his power to avoid such judgment. And the like may be said of memory, and of consciousness. Whether judgment ought to be called a necessary concomitant of these operations, or rather a part or in- gredient of them, I do not dispute ; but it is certain that all of them are accompanied with a determination that something is true or false, and a consequent belief. If this determination be not judgment, it is an operation that has got no name ; for it is not simple apprehension, neither is it reasoning; it is a mental affirmation or negation ; it may be expressed by a propo- sition affirmative or negative, and it is accompanied with the firmest belief. These are the characteristics of judgment ; and I must call it judgment, till I can find another name to it. The judgments we form are either of things necessary, or of things contingent- That three times three is nine, that the whole is greater than a part, are judg- ments about things necessary. [502] Our assent to such necessary propositions is not grounded upon any operation of sense, of memory, or of consciousness, nor does it require their concurrence ; it is unaccom- panied by any other operation but that of conception, which must accompany all judg- ment ; we may therefore call this judgment of things necessary pure judgment. Our judgment of things contingent must always rest upon some other operation of the mind, such as sense, or memory, or consciousness, or credit in testimony, which is itself grounded upon sense. That I now write upon a table covered with green cloth, is a contingent event, which I judge to be most undoubtedly true. My judgment is grounded upon my percep- tion, and is a necessary concomitant or in- gredient of my perception. That I dined * In so far as there can be Consciousness, there must bo Judgment,— H. [500-502'] CHAP. I.] OF JUDGMENT JN GENERAL. 415 with such a company yesterday, I judge to be true, because I remember it ;. and my judgment necessarily goes along with this remembrance, or makes a part of it. There are many forms of speech in com- mon language which shew that the senses, memory and consciousness, are considered as judging faculties. We say that a man judges of colours by his eye, of sounds by h'is ear. We speak of the evidence of sense, the evidence of memory, the evidence of consciousness. Evidence is the ground of judgment ; and when we see evidence, it is impossible not to judge. When we speak of seeing or remember- ing anything, we, indeed, hardly ever add that we judge it to be true. But the rea- son of this appears to be, that such an addition would be mere superfluity of speech, because every one knows that what I see or remember, I must judge to be true, and cannot do otherwise. And, for the same reason, in speaking of anything that is self-evident or strictly de- monstrated, we do not say that we judge it to be true. This would be superfluity of speech, because every man knows th^t we must judge that to be true which we hold self-evident or demonstrated. [503] When you say you saw such a thing, or that you distinctly remember it, or when you say of any proposition that it is self- • evident, or strictly demonstrated, it would be ridiculous after this to ask whether you judge it to be true ; nor would it be less ridiculous in you to inform us that you do. It would be a superfluity of speech of the same kind as if, not content with saying that you saw such an object, you should add that you saw it with your eyes. There is, therefore, good reason why, in speaking or writing, judgment should not be expressly mentioned, when all men know it to be necessarily implied ; that is, when there can be no doubt. In such cases, we barely mention the evidence. But when the evidence mentioned leaves room for doubt, then, without any superfluity or tau- tology, we say we judge the thing to be so, because this is not implied in what was said before. A woman with child never says, that, going such a journey, she carried her child along with her. We know that, while it is in her womb, she must carry it along with her. There are some operations of mind that may be said to carry judgment in their womb, and can no more leave it behind them than the pregnant woman can leave her child. Therefore, in speaking of such operations, it is not expressed. Perhaps this manner of speaking may have led philosophers into the opinion that, in perception by the senses, in memory, and in consciousness, there is no judgment at all. Because it is not mentioned in [503-505] speaking of these faculties, they conclude that it does not accompany them ; that they are only different modes of simple appre- hension, or of acquiring ideas ; and that it is no part of their office to judge. [504] I apprehend the same cause has led Mr Locke into a notion of judgment which I take to be peculiar to him. He thinks that the mind has two faculties conversant about truth and falsehood. First, knowledge; and, secondly, judgment. In the first, the perception of the agreement or disagree- ment of the ideas is certain. In the second, it is not certain, but probable only. According to this notion of judgment, it is not by judgment that I perceive that two and three make five ; it is by the faculty of knowledge. I apprehend there can be no kuowledge without judgment, though there may be judgment without that certainty which we commonly call knowledge. Mr Locke, in another place of hi3 Essay, tells us, " That the notice we have by our senses of the existence of things without us, though not altogether so certain as our in- tuitive knowledge, or the deductions of our reason about abstract ideas, yet is an as- surance that deserves the name of know- ledge." I think, by this account of it, and by his definitions before given of knowledge and judgment, it deserves as well the name of judgment. That I may avoid disputes about the meaning of words, I wish the reader to un- derstand, that I give the name of judgment to every determination of the mind con- cerning what is true or what is false. This, I think, is what logicians, from the days of Aristotle, have called judgment. Whether it be called one faculty, as I think it has always been, or whether a philosopher chooses to split it into two, seems not very material. And, if it be granted that, by our senses, our memory, and consciousness, we not only have ideas or simple apprehen- sions, but form determinations concerning what is true and what is false — whether these determinations ought to be called knowledge or judgment, is of small moment. [505] The judgments grounded upon the evi- dence of sense, of memory, and of conscious- ness, put all men upon a level. The phi- losopher, with regard to these, has no pre- rogative above the illiterate, or even abovG the savage. Their reliance upon the testimony of these faculties is as firm and as well grounded as his. His superiority is in judgments of another kind — in judgments about things abstract and necessary. And he is unwilling to give the name of judg- ment to that wherein the most ignorant and unimproved of the species are hia equals. 41tf ON THE INTELLECTUAL POWERS. [essay n But philosophers have never been able to give any definition of judgment which does not apply to the determinations of our senses, our memory, and conscious- ness, nor any definition of simple appre- hension which can comprehend those deter- minations. Our judgments of this kind are purely the gift of Nature, nor do they admit of improvement by culture. The memory of one man may be more tenacious than that of another ; but both rely with equal assur- ance upon what they distinctly remember. One man's sight may be more acute, or his feeling more delicate, than that of another; but both give equal credit to the distinct testimony of their sight and touch. And, as we have this belief by the con- stitution of our nature, without any effort of our own, so no effort of ours can over- turn it. The sceptic may perhaps persuade him- self, in general, that he has no. ground to believe his senses or his memory : but, in particular cases that are interesting, his disbelief vanishes, and he finds himself under a necessity of believing both. [506^] These judgments may, in the strictest sense, be called judgments of nature. Na- ture has subjected us to them, whether we will or not. They are neither got, nor can they be lost by any use or abuse of our faculties ; and it is evidently necessary for our preservation that it should be so. For, if belief in our senses and in our memory were to be learned by culture, the race of men would perish before they learned this lesson. It is necessary to all men for their being and preservation, and therefore is unconditionally given to all men by the Author of Nature. I acknowledge that, if we were to rest in those judgments of Nature of which we now speak, without building others upon them, they would not entitle us to the deno- mination of reasonable beings. But yet they ought not to be despised, for they are the foundation upon which the grand super- structure of human knowledge must be raised. And, as in other superstructures the foundation is commonly overlooked, so it has been in this. The more sublime attainments of the human mind have at- tracted the attention of philosophers, while they have bestowed but a careless glance upon the humble foundation on which the whole fabric rests. A fourth observation is, that some exer- cise of judgment is necessary in the forma- tion of all abstract and general conceptions, whether more simple or more complex ; in dividing, in defining, and, in general, in forming all clear and distinct conceptions of things, which are tlie only fit materials of reasoning. These operations are allied to each other, and therefore I bring them under one ob- servation. They are more allied to our rational nature than those mentioned in the last observation, and therefore are consi- dered by themselves. That I may not be mistaken, it may be observed that I do not say that abstract notions, or other accurate notions of things, after they have been formed, cannot be barely conceived without any exercise of judgment about them. I doubt not that they may : but what I say is, that, in their formation in the mind at first, there must be some exercise of judgment. [507] It is impossible to distinguish the different attributes belonging to the same subject, without judging that they are really different and distinguishable, and that they have that relation to the subject which logicians ex- press, by saying that they may be predicated of it. We cannot generalise, without judg- ing that the same attribute does or may be- long to many individuals. It has been shewn that our simplest general notions are formed by these two operations of dis- tinguishing and generalising ; judgment therefore is exercised in forming the simplest general notions. In those that are more complex, and which have been shewn to be formed by combining the more simple, there is another act of the judgment required; for such combinations are not made at random, but for an end ; and judgment is employed in fitting them to that end. We form complex general notions for conveniency of arrang- ing our thoughts in discourse and reasoning ; and, therefore, of an infinite number of com- binations that might be formed, we choose only those that are useful and necessary. That judgment must be employed in dividing as well as in distinguishing, ap- pears evident. It is one thing to divide a subject properly, another to cut it in pieces. Hoc-non est dividere, sedfrangere rem, said Cicero, when he censured an improper division of Epicurus. Reason has discovered rules of division, which have been known to logicians more than two thousand years. There are rules likewise of definition of no less antiquity and authority. A man may no doubt divide or define properly with- out attending to the rules, or even without knowing them. But this can only be when he has judgment to perceive that to be right in a particular case, which the rule de- termines to be right in all cases. I add in general, that, without some de- gree of judgment, we can form no accurate and distinct notions of things ; so that one province of judgment is, to aid us in form- ing clear and distinct conceptions of things, which are the only fit materials for reason- ing. [508] [506-508] CHAP, I.] OF JUDGMENT IN GENERAL 417 Thig will probably appear to be a paradox to philosophers, who have always considered the formation of ideas of every kind as be- longing to simple apprehension ; and that the sole province of judgment is to put them together in affirmative or negative proposi- tions ; and therefore it requires some con- firmation. Fint, I think it necessarily follows, from what has been already said in this observa- tion. For if, without some degree of judg- ment, a man can neither distinguish, nor divide, nor define, nor form any general notion, simple or complex, he surely, with- out some degree of judgment, cannot have in his mind the materials necessary to reasoning. There cannot be any proposition in lan- guage which does not involve some general conception. The proposition, that I exist, which Des Cartes thought the first of all truths, and the foundation of all knowledge, cannot be conceived without the conception of existence, one of the most abstract general conceptions- A man cannot believe his own existence, or the existence of anything he sees or remembers, until he has so much judgment as to distinguish things that really exist from things which are only coneeived. He sees a man six feet high ; he conceives a man sixty feet high : he judges the first object to exist, because he sees it ; the second he does not judge to exist, because he only conceives it. Now, I would ask, Whether he can attribute existence to the first object, and not to the second, without knowing what existence means ? It is im- possible. How early the notion of existence enters into the mind, I cannot determine ; but it must certainly be in the mind as soon as we can affirm of anything, with understand- ing, that it exists. [509] In every other proposition, the predicate, at least, must be a general notion — a pre- dicable and an universal being one and the same. Besides this, every proposition either affirms or denies. And no man can have a distinct conception of a proposition, who . does not understand distinctly the meaning of affirming or denying. But these are very general conceptions, and, as was before observed, are derived from judgment, as their source and origin. I am sensible that a strong objection may be made to this reasoning, and that it may seem to lead to an absurdity or a contra- diction. It may be said, that every judg- ment is a mental affirmation or negation. If, therefore, some previous exercise of judgment be necessary to understand what is meant by affirmation or negation, the exercise of judgment must go before any judgment which is absurd. In like manner, every judgment may be [509,510] expressed by a proposition, and a proposi- tion must be conceived before we can judge of it. If, therefore, we cannot conceive the meaning of a proposition without a previous exercise of judgment, it follows that judg- ment must be previous to the conception of any proposition, and at the same time that the conception of a proposition must be pre- vious to all judgment, which is a contra- diction. The reader may please to observe, that I have limited what I have said to distinct conception, and some degree of judgment ; and it is by this means I hope to avoid this labyrinth of absurdity and contradiction. The faculties of conception and judgment have an infancy and a maturity as man has. What I have said is limited to their mature state. I believe in their infant state they are very weak and indistinct ; and that, by imperceptible degrees, they grow to ma- turity, each giving aid to the other, and receiving aid from it. But which of them first began this friendly intercourse, is be- yond my ability to determine. It is like the question concerning the bird and the egg. [510] In the present state of things, it is true that every bird comes from an egg, and every egg from a bird ; and each may be said to be previous to the other. But, if we go back to the origin of things, there must have been some bird that did not come from any egg, or some egg that did not come from any bird. In like manner, in the mature state of man, distinct conception of a proposition supposes some previous exercise of judg- ment, and distinct judgment supposes dis- tinct conception. Each may truly be said to come from the other, as the bird from the egg, and the egg from the bird. But, if we. trace back this succession to its origin that is, to the first proposition that was ever conceived by the man, and the first judgment he ever formed — I determine no- thing about them, nor do I know in what order, or how, they were produced, any more than how the bones grow in the womb of her that is with child. The first exercise of these faculties of conception and judgment is hid, like the sources of the Nile, in an unknown region. The necessity of some degree of judg- ment to clear and distinct conceptions of things, may, I think, be illustrated by this similitude. An artist, suppose a carpenter, cannot work in his art without tools, and these tools must be made by art. The exercise of the art, therefore, is necessary to make the tools, and the tools are necessary to the exercise of the art. There is the same appearance of contradiction, as in what I have advanced concerning the necessity of 2 E 418 ON THE INTELLECTUAL POWERS. [ESSAY VI. some degree of judgment, in order to form clear and distinct conceptions of things. These are the tools we must use in judging and in reasoning, and without them must make very bungling work ; yet these tools cannot be made without some exercise of judgment. [511] The necessity of some degree of judg- ment in forming accurate and distinct no- tions of things will farther appear, if we consider attentively what notions we can form, without any aid of judgment, of the objects of sense, of the operations of our own minds, or of the relations of things. To begin with the objects of sense. It is acknowledged, on all hands, that the first notions we have of sensible objects are got by the external senses only, and probably before judgment is brought forth ; but these first notions are neither simple, nor are they accurate and distinct : they are gross and indistinct, and, like the chaos, a ruiis indigestaque moles. Before we can have any distinct notion of this mass, it must be analysed ; the heterogeneous parts must be separated in our conception, and the simple elements, which before lay hid in the com- mon mass, must first be distinguished, and then put together into one whole. In this way it is that we form distinct notions even of the objects of sense ; but this process of analysis and composition, by habit, becomes so easy, and is performed so readily, that we are apt to overlook it, and to impute the distinct notion we have formed of the object to the senses alone ; and this we are the more prone to do because, when once we have distinguished the sensible qualities of the object from one another, the sense gives testimony to each of them. You perceive, for instance, an object white, round, and a foot in diameter. I grant that you perceive all these attributes of the object by sense ; but, if you had not been able to distinguish the colour from the figure, and both from the magnitude, your senses would only have given you one complex and confused notion of all these mingled together. A man who is able to say with under- standing, or to determine in his own mind, that this object is white, must have distin- guished whiteness from other attributes. If he has not made this distinction, he does not understand what he says. [512] Suppose a cube of brass to be presented at the same time to a child of a year old and to a man. The regularity of the figure will attract the attention of both. Both have the senses of sight and of touch in equal perfection ; and, therefore, if any- thing be discovered in this object by the man, which cannot be discovered by the child, it must be owing, not to the senses, but to some other faculty which the child has not yet attained. First, then, the man can easily distin- guish the body from the surface which terminates it ; this the child cannot do. Secondly, The man can perceive that this surface is made up of six planes of the same figure and magnitude ; the child cannot discover this. Thirdly, The man perceives that each of these planes has four equal sides and four equal angles ; and that the opposite sides of each plane and the oppo- site planes are parallel. It will surely be allowed, that a man of ordinary judgment may observe all this in a cube which he makes an object of con- templation, and takes time to consider; that he may give the name of a square to a plane terminated by four equal sides and four equal angles ; and the name of a cube to a solid terminated by six equal squares : all this is nothing else but analysing the figure of the object presented to his senses into its simplest elements, and again com- pounding it of those elements. By this analysis and composition two effects are produced. First, From the one complex object which his senses presented, though one of the most simple the senses can present, he educes many simple and distinct notions of right lines, angles, plain surface, solid, equality, parallelism ; notions which the child has not yet faculties to attain. Secondly, When he considers the cube as compounded of these elements, put together in a certain order, he has then, and not before, a distinct and scientific notion of a cube. The child neither con- ceives those elements, nor in what order they must be put together in order to make a cube ; and, therefore, has no accurate notion of a cube which can make it a sub- ject of reasoning. [513] Whence I think we may conclude, that the notion which we have from the senses alone, even of the simplest objects of sense, is indistinct and incapable of being either described or reasoned upon, until it is ana- lysed into its simple elements, and con- sidered as compounded of those elements. If we should apply this reasoning to more complex objects of sense, the conclusion would be still more evident. A dog may be taught to turn a jack, but he can never be taught to have a distinct notion of ?. jack. He sees every part as well as a man ; but the relation of the parts to one another and to the whole, he has not judgment to comprehend. A distinct notion of an object, even of sense, is never got in an instant ; but the sense performs its office in an instant. Time is not required to see it better, but to analyse it, to distinguish the different parts, and their relation to one another and to the whole. [511-513] CHAP. I.j OF JUDGMENT IN GENERAL. 419 Hence it is that, when any vehement passion or emotion hinders the cool applica- tion of judgment, we get no distinct notion of an object, even though the sense be long directed to it. A man who is put into a panic, by thinking he sees a ghost, may stare at it long without having any distinct notion of it ; it is his understanding, and not his sense, that is disturbed by his horror. If he can lay that aside, judgment immedi- ately enters upon its office, and examines the length and breadth, the colour, and figure, and distance of the object. Of these, while his panic lasted, he had no distinct notion, though his eyes were open all the time. When the eye of sense is open, but that of judgment shut by a panic, or any violent emotion that engrosses the mind, we see things confusedly, and probably much in the same manner that brutes and perfect idiots do, and infants before the use of judgment. [514] There are, therefore, notions of the objects of sense which are gross and indistinct, and there are others that are distinct and scienti- fic. The former may be got from the senses alone, but the latter cannot be obtained with- out some degree of judgment. The clear and accurate notions which geometry presents to us of a point, a right line, an angle, a square, a circle, of ratios direct and inverse, and others of that kind, can find no admittance into a mind that has not some degree of judgment. They are not properly ideas of the senses, nor are they got by compounding ideas of the senses, but by analysing the ideas or no- tions we get by the senses into their simplest elements, and again combining these ele- ments into various accurate and elegant forms, which the senses never did nor can exhibit. Had Mr Hume attended duly to this, it ought to have prevented a very bold attempt, which he has prosecuted through fourteen pages of his " Treatise of Human Nature," to prove that geometry isfounded upon ideas that are not exact, and axioms that are not precisely true. A mathematician might be tempted to think that the man who seriously under- takes this has no great acquaintance with geometry ; but I apprehend it is to be im- puted to another cause, to a zeal for his own system. We see that even men of genius may be drawn into strange paradoxes, by an attachment to a favourite idol of the understanding, when it demands so costly a sacrifice. We Protestants think that the devotees of the Roman Church pay no small tribute to her authority when they renounce their five senses in obedience to her decrees. Mr Hume's devotion to his system carries him [511-516] even to trample upon mathematical demon- stration. [515] The fundamental articles of his system are, that all the perceptions of the human mind are either impressions or ideas, and that ideas are only faint copies of impres- sions. The idea of a right line, therefore, ip only a faint copy of some line that has been seen, or felt by touch ; and the faint copy cannot be more perfect than the original. Now of such right lines, it is evident that the axioms of geometry are not precisely true ; for two lilies that are straight to our sight or touch may include a space, or they may meet in more points than one. If, therefore, we cannot form any notion of a straight line more accurate than that which we have from the senses of sight and touch, geometry has no solid foundation. If, on the other hand, the geometrical axioms are precisely true, the idea of a right line is not copied from any impression of sight or touch, but must have a different origin and a more perfect standard. As the geometrician, by reflecting only upon the extension and figure of matter, forms a set of notions more accurate and scientific than any which the senses exhi- bit, so the natural philosopher, reflecting upon other attributes of matter, forms another set, such as those of density, quan- tity of matter, velocity, momentum, fluidity, elasticity, centres of gravity, and of oscilla- tion. These notions are accurate and scientific ; but they cannot enter into a mind that has not some degree of judg- ment, nor can we make them intelligible to children, until they have some ripeness of understanding. In navigation, the notions of latitude, longitude, course, leeway, cannot be made intelligible to children ; and so it is with regard to the terms of every science, and of every art about which we can reason. They have had their five senses as perfect as men for years before they are capable of distinguishing, comparing, and perceiv- ing the relations of things, so as to be able to form such notions. They acquire the intellectual powers by a slow progress, and by imperceptible degrees ; and by means of them, learn to form distinct and accurate notions of things, which the senses could never have imparted. [516] Having said so much of the notions we get from the senses alone of the objects of sense, let us next consider what notions we can have from consciousness alone of the operations of our minds. Mr Locke very properly calls conscious- ness an internal sense. It gives the like immediate knowledge of things in the mind — that is, of our own thoughts and feelings — as the senses give us of things external. There is this difference, however, that an 2k 2 420 ON THE INTELLECTUAL POWERS. [essay VI external object may be at rest, and the sense may be employed about it for some time. But the objects of consciousness are never at rest : the stream of thought flows like a river, without stopping a mo- ment ; the whole train of thought passes in succession under the eye of consciousness, which is always employed about the present. But is it consciousness that analyses com- plex operations, distinguishes their different ingredients, and combines them in distinct parcels under general names ? This surely is not the work of consciousness, nor can it be performed without reflection,* recollect- ing and judging of what we were conscious of, and distinctly remember. This reflec- tion does not appear in children. Of all the powers of the mind, it seems to be of the latest growth, whereas consciousness is coeval with the earliest.-)- Consciousness, being a kind of internal sense, can no more give us distinct and accurate notions of the operations of our minds, than the external senses can give of external objects. Reflection upon the operations of our minds is the same kind of operation with that by which we form dis- tinct notions of external objects. They differ not in their nature, but in this only, that one is employed about external, and the other about internal objects ; and both may, with equal propriety, be called reflec- tion. [517] Mr Locke has restricted the word reflec- * See above, p. 2'I2, a, note *.— H. t See above, p. 239, b. — As a corollary of this truth, Mr Stewart makes the following observations, in which he is supported by every competent authority in education. The two northern universities have long withdrawn themselves from the reproach of placing Physics last in their curriculum of arts. In that of Edinburgh, no order is prescribed ; but in St Andrew's and Glasgow, the class of Physics still stands after those of Mental Philosophy. This absurdity is, it is to be observed, altogether of a modern intro- duction. For, when our Scottish universities were founded, and long after, the philosophy of mind was taught by the Professor of Physics. " I apprehend," says Mr Stewart, "that the study of the mind should form the last branch of the education of youth j an order which nature herself seems to point out, by what I have already remarked with respect to the developement of our faculties. After the under, standing is well stored with particular facts, and has been conversant with particular scientific pur- suits, it will be enabled to speculate concerning its own powers with additional advantage, and will run no hazard in indulging too far in such inquiries. Nothing can be more absurd, on this as well as on many other accounts, than the common practice which is followed in our universities, r_in some only, 3 of beginning a course of philosophical education with the study of Logic. If thisorder were completely re- versed ; and if the study of Logic were delayed till after the mind of the student was well stored with particular fact6 in Physics, in Chemistry, in Natural and Civil History, his attention might be led with the most important advantage, and without any dan- ger to his power of observation, to an examination of his own faculties, which, besides opening to him a new and pleasing field of speculation, would enable him to form an estimate of his own powers, of the acquisitions he has made, of the habits he has formed, and of the farther improvements of which his mind u susceptible." — H- tion to that which is employed about the operations of our minds, without any authority, as I think, from custom, the arbiter of language. For, surely, I may reflect upon what I have seen or heard, as well as upon what I have thought.* The word, in its proper and common meaning, is equally applicable to objects of sense, and to objects of consciousness.-)- He has likewise confounded reflection with con- sciousness, and seems not to have been aware that they are different powers, and appear at very different periods of life.$ If that eminent philosopher had been aware of these mistakes about the meaning of the word reflection, he would, I think, have seen that, as it is by reflection upon the operations of our own minds that we can form any distinct and accurate notions of them, and not by consciousness without reflection, so it is by reflection upon the objects of sense, and not by the senses without reflection, that we can form dis- tinct notions of them. Reflection upon any- thing, whether external or internal, makes it an object of our intellectual powers, by which we survey it on all sides, and form such judgments about it as appear to be just and true. I proposed, in the third place, to consi- der our notions of the relations of things : and here I think, that, without judg- ment, we cannot have any notion of rela- tions. There are two ways in which we get the notion of relations. The first is, by com- paring the related objects, when we have before had the conception of both. By this comparison, we perceive the relation, either immediately, or by a process of reasoning. That my foot is longer than my finger, 1 perceive immediately; and that three is the half of six. This immediate perception is immediate and intuitive judgment. That the angles at the base of an isosceles triangle are equal, I perceive by a process of reason- ing, in which it will be acknowledged there is judgment. Another way in which we get the notion of relations (which seems not to have occur- red to Mr Locke) is, when, by attention to one of the related objects, we perceive or judge that it must, from its nature, have a certain relation to something else, which before, perhaps, we never thought of; and thus our attention to one of the related ob- * See note before last, and note at p. 347, b H. t Mr Stewart makes a curious mistatement of the meaning attached by Reid to the word Reflection, if this passage and others are taken into account. — See Elements, I. p. 106, note +. — H. t Consciousness and Reflection cannot be analysed into different powers. Reflection is only, in Locke's meaning of the word, (and this is the more correct,) Consciousness, concentrated by an act of Will on the phtenomena of mind— i. e., internal Attention ; In Reid's, what is it but Attention in general ?— H. [517] CJHAP. II. j OF COMMON SENSE. 421 jects produces the notion of a correlate, and of a certain relation between them. [518] Thus, when I attend to colour, figure, weight, I cannot help judging these to be qualities which cannot exist without a sub- ject ; that is, something which is coloured, figured, heavy. If I had not perceived such things to be qualities, I should never have had any notion of their subject, or of their relation to it. By attending to the operations of think- ing, memory, reasoning, we perceive or judge that there must be something which thinks, remembers, and reasons, which we call the mind. When we attend to any change that happens in Nature, judgment informs us that there must be a cause of this change, which had power to produce it; and thus we get the notions of cause and effect, and of the relation between them. When we attend to body, we per- ceive that it cannot exist without space ; hence we get the notion of space, (which is neither an object of sense nor of conscious- ness,) and of the relation which bodies have to a certain portion of unlimited space, as their place. I apprehend, therefore, that all our no- tions of relations may more properly be ascribed to judgment as their source and origin, than to any other power of the mind. We must first perceive relations by our judgment, before we can conceive them without judging of them ; as we must first perceive colours by sight, before we can conceive them without seeing them. I think Mr Locke, when he comes to speak of the ideas of relations, does not say that they are ideas of sensation or reflection, but only that they terminate in, and are concerned about, ideas of sensation or re- flection. [519] The notions of unity and number are so abstract, that it is impossible they should enter into the mind until it has some degree of judgment. We see with what difficulty, and how slowly, children learn to use, with understanding, the names even of small numbers, and how they exult in this acqui- sition when they have attained it. Every number is conceived by the relation which it bears to unity, or to known combinations of units ; and upon that account, as well as on account of its abstract nature, all distinct notions of it require some degree of judgment^ In its proper place, I shall have occasion to shew that judgment is an ingredient in all determinations of taste, in all moral determinations, and in many of our pas- sions and affections. So that this opera- tion, after we come to have any exercise of judgment, mixes with most of the operations of our minds, and, in analysing them, cannot be overlooked without confusion and error. F518-520] CHAPTER II. OF COMMON SENSE." The word sense, in common language, seems to have a different meaning from that which it has in the writings of philosophers ; and those different meanings are apt to be confounded, and to occasion embarrassment and error. Not to go b^ck to ancient philosophy upon this point, modern philosophers consider sense as a power that has nothing to do with judgment. Sense they consider as the power by which we receive certain ideas or im- pressions from objects ; and judgment as the power by which we compare those ideas, and perceive their necessary agree- ments and disagreements. [520] The external senses give us the idea of colour, figure, sound, and other qualities of body, primary or secondary. Mr Locke gave the name of an internal sense to con- sciousness, because by it we have the ideas of thought, memory, reasoning, and other operations of our own minds. Dr Hutche- son of Glasgow, conceiving that we have simple and original ideas which cannot be imputed either to the external senses or to consciousness, introduced other internal senses ; such as the sense of harmony, the sense of beauty, and the moral sense. Ancient philosophers also spake of internal senses, of which memory was accounted one. But all these senses, whether external or internal, have been represented by philo- sophers as the means of furnishing our minds with ideas, without including any kind of judgment. Dr Hutcheson defines a sense to be a determination of the mind to receive any idea from the presence of an object independent on our will. " By this term (sense) philosophers, in general, have denominated those faculties in consequence of which we are liable to feelings relative to ourselves only, and from which they have not pretended to draw any conclusions concerning the nature of things ; whereas truth is not relative, but absolute and real (Dr Priestly's " Examination of Dr Reid," &c, p. 123.) On the contrary, in common language, sense always implies judgment. A man of sense is a man of judgment. Good sense is good judgment. Nonsense is what is evidently contrary to right j udgment. Com- mon sense is that degree of judgment which is common to men with whom we can con- verse and transact business. Seeing and hearing, by philosophers, are called senses, because we have ideas by * On Common Sente. name and thing] ree Note A. — H. 422 ON THE INTELLECTUAL POWERS. ESSAY VI. them ; by the vulgar they are called senses, because we judge by them. We judge of colours by the eye ; of sounds by the ear ; of beauty and deformity by taste ; of right and wrong in conduct, by our moral sense or conscience. [521] Sometimes philosophers, who represent it as the sole province of sense to furnish us with ideas, fall unawares into the popu- lar opinion that they are judging faculties. Thus Locke, Book IV. chap. 2 :— " And of this, (that the quality or accident of colour doth really exist, and hath a being without me,) the greatest assurance I can possibly have, and to which my faculties can attain, is the testimony of my eyes, which are the proper and sole judges of this thing." This popular meaning of the word sense is not peculiar to the English language. The corresponding words in Greek, Latin, and, I believe, in aU the European languages, have the same latitude. The Latin words sentire, sententia, sensa* sensus, from the last of which the English word sense is borrowed, express judgment or opinion, and are applied indifferently to objects of exter- nal sense, of taste, of morals, and of the understanding. I cannot pretend to assign the reason why a word, which is no term of art, which is familiar in common conversation, should have so different a meaning in philosophical writings. I shall only observe, that the philosophical meaning corresponds perfectly with the account which Mr Locke and other modern philosophers give of judgment. For, if the sole province of the senses, external and internal, be to furnish the mind with the ideas about which we judge and reason, it seems to be a natural consequence, that the sole province of judgment should be to compare those ideas, and to perceive their necessary relations. These two opinions seem to be so con- nected, that one may have been the cause of the other. I apprehend, however, that, if both be true, there is no room left for any knowledge or judgment, either of the real existence of contingent things, or of their contingent relations. To return to the popular meaning of the word sense. I believe it would be much more difficult to find good authors who never use it in that meaning, than to find such as do. [522] We may take Mr Pope as good authority for the meaning of an English word. He uses it often, and, in his " Epistle to the Earl of Burlington," has made a little de- scant upon it. * What does sensa mean ? Is it an erratum, or does he refer to sensa, once only, I believe, employed by Cicero, and interpreted by Nonius Marcellus, as ■" qua? sentiuntur 9" — H. " Oft have you hinted to your brother Peer, A certain truth, which many buy too dear: Something there is more needful than expense, And something previous ev'n to taste — 'tis sense. Good sense, which only is the gifW>f heaven, And, though no science, fairly worth the seven ; A light which in yourself you must perceive, Jones and Le Notre have it not to give," This inward light or sense is given by heaven to different persons in different de- grees. There is a certain degree of it which is necessary to our being subjects of law and government, capable of managing our own affairs, and answerable for our conduct towards others : this is called common sense, because it is common to all men with whom we can transact business, or call to account for their conduct. The laws of all civilised nations distin- guish those who have this gift of heaven, from those who have it not. The last may have rights which ought not to be violated, but, having no understanding in themselves to direct their actions, the laws appoint them to be guided by the understanding of others. It is easily discerned by its effects in men's actions, in their speeches, and even in their looks ; and when it is made a question whether a man has this natural gift or not, a judge or a jury, upon a short conversation with him, can, for the most part, determine the question with great assurance. The same degree of understanding which makes a man capable of acting with com- mon prudence in the conduct of life, makes him capable of discovering what is true and what is false in matters that are self-evident, and which he distinctly apprehends. [523] All knowledge, and all science, must be built upon principles that are self-evident ; and of such principles every man who has common sense is a competent judge, when he conceives them distinctly. Hence it is, that disputes very often terminate in an appeal to common sense. While the parties agree in the first prin- ciples on which their arguments are ground- ed, there is room for reasoning ; but when one denies what to the other appears too evident to need or to admit of proof, rea- soning seems to be at an end ; an appeal is made to common sense, and each party is left to enjoy his own opinion. There seems to be no remedy for this, nor any way left to discuss such appeals, unless the decisions of common sense can be brought into a code in which all reason- able men shall acquiesce. This, indeed, if it be possible, would be very desirable, and would supply a desideratum in logic ; and why should it be thought impossible that reasonable men should agree in things that are self-evident ? All that is intended in this chapter is to explain the meaning of common sense, that it may not be treated, as it has been by some, as a new principle, or as a word with- [521-523] CHAP. II. j OF COMMON SENSE!. 423 out any meaning. I have endeavoured to shew that sense, in its most common, and therefore its most proper meaning, signifies judgment, though philosophers often use it in another meaning. From this it is natural to think that common sense should mean common judgment; and so it really does. What the precise limits are which divide common judgment from what is beyond it on the one hand, and from what falls short of it on the other, may be difficult to de- termine ; and men may agree in the mean- ing of the word who have different opinions about those limits, or who even never thought of fixing them. This is as intel- ligible as, that all Rnglishmen should mean the same thing by the county of York, though perhaps not a hundredth part of them can point out its precise limits. [524] Indeed, it seems to me, that common sense is as unambiguous a word and as well understood as the county of York. We find it in innumerable places in good writers ; we hear it on innumerable occasions in con- versation ; and, as far as I am able to judge, always in the same meaning. And this is probably the reason why it is so seldom defined or explained. Dr Johnson, in the authorities he gives, to shew that the word sense signifies under- standing, soundness of faculties, strength of natural reason, quotes Dr Bentley for what may be called a definition of common sense, though probably not intended for that pur- pose, but mentioned accidentally : " God hath endowed mankind with power and abilities, which we call natural light and reason, and common sense." It is true that common sense is a popular and not a scholastic word ; and by most of those who have treated systematically of the powers of the understanding, it is only occasionally mentioned, as it is by other writers. But I recollect two philosophical writers, who are exceptions to this remark. One is Buffier, who treated largely of com- mon sense, as a principle of knowledge, above fifty years ago. The other is Bishop Berkeley, who, I think, has laid as much stress upon common sense, in opposition to the doctrines of philosophers, as any philo- sopher that has come after him. If the reader chooses to look back to Essay II. chap. 10, he will be satisfied of this, from the quotations there made for another pur- pose, which it is unnecessary here to repeat. Men rarely ask what common sense is ; because every man believes himself pos- sessed of it, laid would take it for an imput- ation upon his understanding to be thought unacquainted with it. Yet I remember two very eminent authors who have put this question ; and it is not improper to hear their sentiments upon a subjectso frequently mentioned, and so rarely canvassed. [525] 5S4-58S"] It is well known that Lord Shaftesbury gave to one of his Treatises the title of " Sensus Communis; an Essay on the Freedom of Wit and Humour, in a Letter to a Friend ;" in which he puts his friend in mind of a free conversation with some of their friends on the subjects of morality and religion. Amidst the different opinions started and maintained with great life and ingenuity, one or other would, every now and then, take the liberty to appeal to common sense. Every one allowed the appeal ; no one would offer to call the authority of the court in question, till a gentleman whose good understanding was never yet brought in doubt, desired the company, very gravely, that they would tell him what common sense was. " If," said he, " by the word sense, we were to understand opinion and judgment, and by the word common, the generality or any considerable part of mankind, it would be hard to discover where the subject of common sense could lie ; for that which was according to the sense of one part of mankind, was against the sense of another. And if the majority were to determine com- mon sense, it would change as often as men changed. That in religion, common sense was as hard to determine as catholic or orthodox. What to one was absurdity, to another was demonstration. " In policy, if plain British or Dutch sense were right, Turkish and French must certainly be wrong. And as mere non- sense as passive obedience seemed, we found it to be the common sense of a great party amongst ourselves, » greater party in Europe, and perhaps the greatest part of all the world besides. As for morals, the difference was still wider ; for even the philosophers could never agree in one and the same system. And some even of our most admired modern philosophers had fairly told us that virtue and vice had no other law or measure than mere fashion and vogue." [526] This is the substance of the gentleman's speech, which, I apprehend, explains the meaning of the word perfectly, and contains all that has been said or can be said against the authority of common sense, and the propriety of appeals to it. As there is no mention of any answer immediately made to this speech, we might be apt to conclude that the noble author adopted the sentiments of the intelligent gentleman whose speech he recites. But the contrary is manifest, from the title of Sensus Communis given to his Essay, from his frequent use of the word, and from the whole tenor of the Essay. The author appears to have a double in- tention in that Essay, corresponding to the double title prefixed to it. One intention 424 ON THE INTELLECTUAL POWERS. £ESS.AV VI. is, to justify the use of wit, humour, and ridicule, in discussing among friends the gravest subjects. " I can very well sup- pose," says he, " men may be frighted out of their wits ; but I have no apprehen- sion they should be laughed out of them. I can hardly imagine that, in a pleasant way, they should ever be talked out of their love for society, or reasoned out of humanity and common sense.' 1 The other intention, signified by the title Sensus Communis, is carried on hand in hand with the first, and is to shew that common sense is not so vague and uncertain a thing as it is represented to be in the sceptical speech before recited. " I will try," says he, " what certain knowledge or assurance of things may be recovered in that very way, (to wit, of humour,) by which all certainty, you thought, was lost, andanendlessscepticismintroduced." [527] He gives some criticisms upon the word sensus communis in Juvenal, Horace, and Seneca ; and, after shewing, in a facetious way throughout the treatise, that the fun- damental principles of morals, of polities, of criticism, and of every branch of knowledge, are the dictates of common sense, he sums up the whole in these words : — " That some moral and philosophical truths there are so evident in themselves that it would be easier to imagine half mankind run mad, and joined precisely in the same species of folly, than to admit anything as truth which should be advanced against such natural knowledge, fundamental reason ; and common sense. " And, on taking leave, he adds : — " And now, my friend, should you find I had moralised in any tolerable manner, according to common sense, and without canting, I should be satisfied with my performance." Another eminent writer who has put the question what common sense is, is Fenelon, the famous Archbishop of Cambray. That ingenious and pious author, having had an early prepossession in favour of the Cartesian philosophy, made an attempt to establish, on a. sure foundation, the meta- physical arguments which Des Cartes had invented to prove the being of the Deity. For this purpose, he begins with the Carte- sian doubt. He proceeds to find out the truth of his own existence, and then to ex- amine wherein the evidence and certainty of this and other such primary truths con- sisted. This, according to Cartesian prin- ciples, he places in the clearness and dis- tinctness of the ideas. On the contrary, he places the absurdity of the contrary pro- positions, in their being repugnant to his clear and distincfideas. To illustrate this, he gives various ex- amples of questions manifestly absurd and ridiculous, which every man of common understanding would, at first sight, perceive to be so ; and then goes on to this purpose. " What is it that makes these questions ridiculous? Wherein does this ridicule precisely consist ? It will, perhaps, be replied, that it consists in this, that they shock common sense. But what is this same common sense ? It is not the first notions that all men have equally of the same things. [528] This common sense, which is always and in all places the same j which prevents inquiry ; which makes in- quiry in some cases ridiculous ; which, in- stead of inquiring, makes a man laugh whether he will or not ; which puts it out of a man's power to doubt: this sense, which only waits to be consulted — which shews itself at the first glance, and imme- diately discovers the evidence or the absurd- ity of a question — is not this the same that I call my ideas ? " Behold, then, those ideas or general notions, which it is not in my power either to contradict or examine, and by which I examine and decide in every case, insomuch that I laugh instead of answering, as often as anything is proposed to me, which is evi- dently contrary to what these immutable ideas represent." I shall only observe upon this passage, that the interpretation it gives of Des Cartes' criterion of truth, whether just or not, is the most intelligible and the most favourable I have met with. I beg leave to mention one passage from Cicero, and to add two or three from late writers, which shew that this word is not become obsolete, nor has changed its meaning. "De Oratore," lib. 3 — "Omnes enim tacito quodam sensu, sine ulla arte aut ratione, in artibus ac rationibus, recta ac prava dijudicant. Idque cum faciant in picturis, et in signis, et in aliis operibus, ad quorum intelligentiam a natura minus hab- ent instrumenti, turn multo ostendunt magis in verborum, numerorum, vocumque judi- cio ; quod ea sint in communibus infixa sensibus ; neque earurn rerum quemquam funditus natura voluit expertem." " Hume's " Essays and Treatises," vol. I. p. 5 — " But a philosopher who proposes only to represent the common sense of mankind in more beautiful and more engag- ing colours, if by accident he commits a mistake, goes no farther, but, renewing his appeal to common sense, and the natural sentiments of the mind, returns into the right path, and secures himself from any dangerous illusion." [529] Hume's " Enquiry concerning the Prin- ciples of Morals," p. 2 — " Those who have refused the reality of moral distinctions may be ranked among the disingenuous dis- putants. The only way of converting an •527-529 | dHAP. II. J OF COMMON SENSE. 425 antagonist of this kind is to leave him to himself : for, finding that nobody keeps up the controversy with him, it is probable he will at last, of himself, from mere weariness, come over to the side of common sense and reason." Priestley's " Institutes," Preliminary Essay, vol. i. p. 27 — " Because common sense is a sufficient guard against many errors in religion, it seems to have been taken for granted that that common sense is a sufficient instructor also, whereas in fact, without positive instruction, men would naturally have been mere savages with respect to religion ; as, without similar in- struction, they would be savages with re- spect to the arts of life and the sciences- Common sense can only be compared to a judge; but what can a judge do without evidence and proper materials from which to form a judgment ?" Priestley's " Examination of Dr Reid," &c. page 127. — " But should we, out of complaisance, admit that what has hitherto been called judgment may be called sense, it is making too free with the established signification of words to call it common sense, which, in common acceptation, has long been appropriated to a very different thing — viz., to that capacity for judging of common things that persons of middling capacities are capable of." Page 129. — " I should, therefore, expect that, if a man was so totally deprived of common sense as not to be able to distinguish truth from false- hood in one case, he would be equally in- capable of distinguishing it in another." [530] From this cloud of testimonies, to which hundreds might be added, I apprehend, that whatever censure is thrown upon those who have spoke of common sense as a prin- ciple of knowledge, or who have appealed to it in matters that are self-evident, will fall light, when there are so many to share in it. Indeed, the authority of this tribunal is too sacred and venerable, and has pre- scription too long in its favour to be now wisely called in question. Those who are disposed to do so, may remember the shrewd saying of Mr Hobbes-^" When reason is against a man, a man will be against rea- son." This is equally applicable to com- mon sense. From the account I nave given of the meaning of this term, it is easy to judge both of the proper use and of the abuse of it. It is absurd to conceive that there can be any opposition between reason and com- mon sense.* It is indeed the first-born of Season ; and, as they are commonly joined * See above, p. 10O, b, note f ; and Mr Stewart's ■■ Elements," II. p. 92.— H. 530, 531] together in speech and in writing, they are inseparable in their nature. We ascribe to reason two offices, or two degrees. The first is to judge of things self-evident ; the second to draw conclusions that are not self-evident from those that are. The first of these is the province, and the sole province, of common sense ; and, therefore, it coincides with reason in its whole extent, and is only another name for one branch or one degree of reason. Per- haps it may be said, Why then should you give it a particular name, since it is acknow- ledged to be only a degree of reason ? It would be a sufficient answer to this, Why do you abolish a name which is to be found in the language of all civilized nations, and has acquired a right by prescription ? Such an attempt is equally foolish and ineffectual. Every wise man will be apt to think that a name which is found in all languages as far back as we can trace them, is not with- out some use. 1531] But there is an obvious reason why this degree of reason should have a name ap- propriated to it ; and that is, that, in the greatest part of mankind, no other degree of reason is to be found. It is this degree that entitles them to the denomination of reasonable creatures. It is this degree of reason, and this only, that makes a man capable of managing his own affairs, and answerable for his conduct towards others. There is therefore the best reason why it should have a name appropriated to it. These two degrees of reason differ in other respects, which would be sufficient to entitle them to distinct names. The first is purely the gift of Heaven. And where Heaven has not given it, no education can supply the want. The se- cond is learned by practice and rules, when the first is not wanting. A man who has common sense may be taught to reason. But, if he has not that gift, no teaching will make him able either to judge of first prin- ciples or to reason from them. I have only this farther to observe, that the province of common sense is more ex- tensive in refutation than in confirmation. A conclusion drawn by a train of just rea- soning from true principles cannot possibly contradict any decision of common sense, because truth will always be consistent with itself. Neither can such a conclu- sion receive any confirmation from com- mon sense, because it is not within its juris- diction. But it is possible that, by setting out from false principles, or by an error in reasoning, a man may be led to a conclu- sion that contradicts the decisions of com- mon sense. In this case, the conclusion is within the jurisdiction of common sense, though the reasoning on which it was 426 ON THE INTELLECTUAL POWERS. [ESS A* VI. grounded be not ; and a man of common sense may fairly reject the conclusion with- out being able to shew the error of the rea- soning that led to it. [532] Thus, if a mathematician, by a process of intricate demonstration, in which some false step was made, should be brought to this conclusion, that two quantities, which are both equal to a third, are not equal to each other, a man of common sense, with- out pretending to be a judge of the demon- stration, is well entitled to reject the con- clusion, and to pronounce it absurd. CHAPTER III. SENTIMENTS OP PHILOSOPHERS CONCERNING JUDGMENT. A difference about the meaning of a word ought not to occasion disputes among philosophers ; but it is often very proper to take notice of such differences, in order to prevent verbal disputes. There are, in- deed, no words in language more liable to ambiguity than those by which we express the operations of the mind ; and the most candid and judicious may sometimes he led into different opinions about their precise meaning. I hinted before what I take to be a pecu- liarity in Mr Locke with regard to the ■meaning of the word judgment, and men- tioned what, I apprehend, may have led him into it. But let us hear himself, Essay, book iv. chap. 14 : — " The faculty which God has given to man to supply the want of clear and certain knowledge, where that cannot be had, is judgment ; whereby the mind takes its ideas to agree or disagree ; or, which is the same, any proposition to be true or false, without perceiving a de- monstrative evidence in the proofs. Thus the mind has two faculties conversant about truth and falsehood. First, Knowledge, whereby it certainly perceives, and is un- doubtedly satisfied of, the agreement or disagreement of any ideas. Secondly, Judgment, which is the putting ideas to- gether, or separating them from one an- other in the mind, when their certain agree- ment or disagreement is not perceived, hut presumed to be so" [533] Knowledge, I think, sometimes signifies things known ; sometimes that act of the mind by which we know them. And in like manner opinion sometimes signifies things believed ; sometimes the act of the mind by which we believe them. But judgment is the faculty which is exercised in both these acts of the mind. In knowledge, we judge without doubting ; in opinion, with some mixture of doubt. But I know no ~w.L,iuniy, besides that of Mr Locke, for calling knowledge a faculty, any more than for calling opinion a faculty. Neither do I think that knowledge is confined within the narrow limits which Mr Locke assigns to it; because the far greatest part of what all men call human knowledge, is in things which neither ad- mit of intuitive nor of demonstrative proof. I have all along used the word judgment in a more extended sense than Mr Locke does in the passage above-mentioned. I understand by it that operation of mind by which we determine, concerning anything that may be expressed by a proposition, whether it be true or false. Every propo- sition is either true or false ; so is every judgment. A proposition may be simply conceived without judging of it. But when there is not only a conception of the pro- position, but a mental affirmation or nega- tion, an assent or dissent of the understand- ing, whether weak or strong, that is judg- ment. I think that, since the days of Aristotle, logicians have taken the word in that sense, and other writers, for the most part, though there are other meanings, which there is no danger of confounding with this. [534] We may take the authority of Dr Isaac Watts, as a logician, as a man who under- stood English, and who had a just esteem of Mr Locke's Essay. Logic. Introd. page 5 — " Judgment is that operation of the mind, wherein we join two or more ideas together by one affirmation or negation; that is, we either affirm or deny this to be that. So: this tree is high ; that horse is not swift ; the mind of man is a thinking being; mere matter has no thought belonging to it; God is just ; good men are often miserable in this world ; a righteous governor will make a difference betwixt the evil and the good; which sentences are the effect of judgment, and are called propositions." And, Part II. chap. ii. § 9 — " The evidence of sense is, when we frame a proposition according to the dictate of any of our senses. So we judge that grass is green ; that a trumpet gives a pleasant sound ; that fire burnswood; , water is soft ; and iron hard." In this meaning, judgment extends to every kind of evidence, probable or certain and to every degree of assent or dissent. It extends to all knowledge as well as to all opinion ; with this difference only, that in knowledge it is more firm and steady, like a house founded upon a rock. In opinion it stands upon a weaker foundation, and is more liable to be shaken and overturned. These differences about the meaning of words are not mentioned as if truth was on one side and error on the other, but as an apology for deviating, in this instance, from the phraseology of Mr Locke, which is, for [533-534J dHAP. m.j SENTIMENTS CONCERNING JUDGMENT. 427 the most part, accurate and distinct ; and because attention to the different meanings that are put upon words by different authors, is the best way to prevent our mistaking verbal differences for real differences of opinion. The common theory concerning ideas naturally leads to a theory concerning judgment, which may be a proper test of its truth; for, as they are necessarily con- nected, they must stand or fall together. Their connection is thus expressed by Mr Locke, Book IV. chap. 1— " Since the mind, in all its thoughts and reasonings, hath no other immediate object but its own ideas, which it alone does or can con- template, it is evident that our knowledge is only conversant about them. Knowledge then seems to me to be nothing but the perception of the connection and agreement, or disagreement and repugnancy, of any of our ideas. In this alone it consists." [535] There can only be one objection to the justice of this inference ; and that is, that the antecedent proposition from which it is inferred seems to have some ambiguity ; for, in the first clause of that proposition, the mind is said to have no other immediate object but its own ideas; in the second, that it has no other object at all ; that it does or can contemplate ideas alone." If the word immediate in the first clause be a mere expletive, and be not intended to limit the generality of the proposition, then the two clauses will be perfectly consistent, the second being only a repetition or expli- cation of the first ; and the inference that our knowledge is only conversant about ideas will be perfectly just and logical. But, if the word immediate in the first clause be intended to limit the general pro- position, and to imply that the mind has other objects besides its own ideas, though no other immediate objects, then it will not be true that it does or can contemplate ideas alone ; nor will the inference be justly drawn that our knowledge is only conversant about ideas- Mr Locke must either have meant his antecedent proposition, without any limita- tion by the word immediate, or he must have meant to limit it by that word, and to signify that there are objects of the mind which are not ideas. The first of these suppositions appears to me most probable, for several reasons. [536] First, Because, when he purposely de- fines the word idea, in the introduction to the Essay, he says it is whatsoever is the * In reference to the polemic that follows, see, for a solution, what has been said above in regard to the ambiguity of the term object* and Note B. In regard to the doctrine of Ideas, as held by the philosophers, see above, and Note C, &c. — H. [535-537] object of the understanding when a man thinks, or whatever the mind can be em- ployed about in thinking. Here there is no room left for objects of the mind that are not ideas. The same definition is often repeated throughout the Essay. Some- times, indeed, the word immediate is added, as in the passage now under consideration ; but there is no intimation made that it ought to be understood when it is not expressed. Now, if it had really been his opinion that there are objects of thought which are not ideas, this definition, which is the ground- work of the whole Essay, would have been very improper, and apt to mislead his reader. Secondly, He has never attempted to shew how there can be objects of thought which are not immediate objects; and, indeed, this seems impossible. For, what- ever the object be, the man either thinks of it, or he does not. There is no medium between these. If he thinks of it, it is an immediate object of thought while he thinks of it. If he does not think of it, it is no object of thought at all. Every object of thought, therefore, is an immediate object of thought, and the word immediate, joined to objects of thought, seems to be a mere expletive. Thirdly, Though Malebranche and Bishop Berkeley believed that we have no ideas of minds, or of the operations of minds, and that we may think and reason about them without ideas, this was not the opinion of Mr Locke. He thought that there are ideas of minds, and of their operations, as well as of the objects of sense ; that the mind perceives nothing but its own ideas, and that all words are the signs of ideas. A fourth reason is, That to suppose that he intended to limit the antecedent proposi- tion by the word immediate, is to impute to him a blunder in reasoning, which I do not think Mr Locke could have committed; for what can be a more glaring paralogism than to infer that, since ideas are partly, though not solely, the objects of thought, it is evident that all our knowledge is only conversant about them. If, on the con- trary, he meant that ideas are the only ob- jects of thought, then the conclusion drawn is perfectly just and obvious ; and he might very well say, that, since it is ideas only that the mind does or can contemplate, it is evi~ dent that our knowledge is only conversant about them. [537] As to the conclusion itself, I have only to observe, that, though he extends it only to what he calls knowledge, and not to what he calls judgment, there is the same reason for extending it to both. It is true of judgment, as well as of knowledge, that it can only be conversant about objects of the mind, or about things 428 ON THE INTELLECTUAL POWERS. [essay vi, which the mind can contemplate. Judg- ment, as well as knowledge, supposes the conception of the object about which we judge ; and to judge of objects that never were nor can be objects of the mind, is evi- dently impossible. This, therefore, we may take for granted, that, if knowledge be conversant about ideas only, because there is no other object of the mind, it must be no less certain that judg- ment is conversant about ideas only, for the same reason. Mr Locke adds, as the result of his rea- soning, " Knowledge, then, seems to me to be nothing but the perception of the con- nection and agreement, or disagreement and repugnancy, of any of our ideas. In this alone it consists.'* This is a very important point, not only on its own account, but on account of its necessary connection with his system con- cerning ideas, which is such as that both must stand or fall together ; for, if there is any part of human knowledge which does not consist in the perception of the agree- ment or disagreement of ideas, it must fol- low that there are objects of thought and of contemplation which are not ideas. [538] This point, therefore, deserves to be care- fully examined. With this view, let us first attend to its meaning, which, I think, can hardly be mistaken, though it may need some explication. Every point of knowledge, and every judgment, is expressed by a proposition, wherein something is affirmed or denied of the subject of the proposition. By perceiving the connection or agree- ment of two ideas, I conceive, is meant per- ceiving the truth of an affirmative proposi- tion, of which the subject and predicate are ideas. In like manner, by perceiving the disagreement and repugnancy of any two ideas, I conceive is meant perceiving the truth of a negative proposition, of which both subject and predicate are ideas. This I take to be the only meaning the words can bear, and it is confirmed by what Mr Locke says in a passage already quoted in this chapter, -that " the mind, taking its ideas to agree or disagree, is the same as taking any proposition to be true or false. 1 ' Therefore, if the definition of knowledge given by Mr Locke be a just one, the sub- ject, as well as the predicate of every pro- position, by which any point of knowledge is expressed, must be an idea, and can be nothing else ; and the same must hold of every proposition by which judgment is expressed, as has been shewn above. Having ascertained the meaning of this definition of human knowledge, we are next to consider how far it is just. First, I would observe that, if the word idea be taken in the meaning which it had at first among the Pythagoreans and Pla- tonists, and if by knowledge be meant only abstract and general knowledge, (which I believe Mr Locke had chiefly in his view,) I think the proposition is true, that such knowledge consists solely in perceiving the truth of propositions whose subject and predicate are ideas. [539] By ideas here I mean things conceived abstractly, without regard to their existence. We commonly call them abstract notions, abstract conceptions, abstract ideas — the Peripatetics called them universals ; and the Platonists, who knew no other ideas, called them ideas without addition. Such ideas are both subject and predicate in every proposition which expresses ab- stract knowledge. The whole body of pure mathematics is an abstract science ; and in every mathe- matical proposition, both subject and pre- dicate are ideas, in the senseabove explained. Thus, when I say the side of a square is not commensurable to its diagonal — in this proposition the side and the diagonal of a square are the subjects, (for, being a rela- tive proposition, it must have two subjects.) A square, its side, and its diagonal, are ideas, or universals ; they are not indivi- duals, but things predicable of many indi- viduals. Existence is not included in their definition, nor in the conception we form of them. The predicate of the proposition is commensurable, which must be an univer- sal, as the predicate of every proposition is so. In other branches of knowledge, many abstract truths may be found, but, for the most part, mixed with others that are not abstract. I add, that I apprehend that what is strictly called demonstrative evidence, is to be found in abstract knowledge only. This was the opinion of Aristotle, of Plato, and, I think, of all the ancient philosophers ; and I be- lieve in this they judged right. It is true, we often meet with demonstration in astro- mony, in mechanics, and in other branches of natural philosophy ; but, I believe, we shall always find that such demonstrations are grounded upon principles of supposi- tions, which have neither intuitive nor demonstrative evidence. [540] Thus, when we demonstrate that the path of a projectile in vacuo is a parabola, we suppose that it is acted upon with the same force and in the same direction through its whole path by gravity. This is not intuitively known, nor is it demon- strable ; and, in the demonstration, we rea- son from the laws of motion, which are principles not capable of demonstration, but grounded on a different kind of evidence. Ideas, in the sense above explained, are creatures of the mind ; they are fabricated LS38-5J03 chap, m.] SENTIMENTS CONCERNING JUDGMENT. 429 by its rational powers ; we know their nature and their essence— for they are nothing more than they are conceived to be ; — and, because they are perfectly known, we can reason about them with the highest degree of evidence. And, as they are not things that exist, but things conceived, they neither have place nor time, nor are they liable to change. When we say that they are in the mind, this can mean no more but that they are conceived by the mind, or that they are objects of thought. The act of conceiving them is, no doubt, in the mind ; the things conceived have no place, because they have not existence. Thus, a. circle, considered abstractly, is said figuratively to be in the mind of him that conceives it ; but in no other sense than the city of London or the kingdom of France is said to be in his mind when he thinks of those objects. Place and time belong to finite things that exist, but not to things that are barely con- ceived. They may be objects of concep- tion to intelligent beings in every place and at all times. Hence the Pythagoreans and Platonists were led to think that they are eternal and omnipresent. If they had ex- istence, they must be so ; for they have no relation to any one place or time, which they have not to every place and to every time. The natural prejudice of mankind, that what we conceive must have existence, led those ancient philosophers to attribute ex- istence to ideas ; and by this they were led into all the extravagant and mysterious parts of their system. When it is purged of these, I apprehend it to be the only in- telligible and rational system concerning ideas. [541] I agree with them, therefore, that ideas are immutably the same in all times and places ; for this means no more but that a circle is always a circle, and a square always a square. I agree with them that ideas are the pat- terns or exemplars by which everything was made that had a beginning: for an intelligent artificer must conceive his work before it is made ; he makes it according to that conception ; and the thing conceived, before it exists, can only be an idea. I agree with them that every species of things, considered abstractly, is an idea; and that the idea of the species is in every individual of the species, without division or multiplication. This, indeed, is expressed somewhat mysteriously, according to the manner of the sect ; but it may easily be explained. Every idea is an attribute ; and it is a common way of speaking to say, that the attribute is in every subject of which it may r 541-543l truly be affirmed. Thus, to be above fifty years of age is an attribute or idea. This attribute may be in, or affirmed of, fifty different individuals, and be the same in all, without division or multiplication. I think that not only every species, but every genus, higher or lower, and every attribute considered abstractly, is an idea. These are things conceived without regard to existence ; they are universals, and, there- fore, ideas, according to the ancient mean- ing of that word. [542] It is true that, after the Platonists en- tered into disputes with the Peripatetics, in order to defend the existence of eternal ideas, they found it prudent to contract the line of defence, and maintained only that there is an idea of every species of natural things, but not of the genera, nor of things artificial. They were unwilling to multiply beings beyond what was necessary; but in this, I think, they departed from the genuine principles of their system. The definition of a species is nothing but the definition of the genus, with the addition of a specific difference ; and the division of things into species is the work of the mind, as well as their division into genera and classes. A species, a genus, an order, a class, is only a combination of at- tributes made by the mind, and called by one name. There is, therefore, the same reason for giving the name of idea to every attribute, and to every species and genus, whether higher or lower : these are only more complex attributes, or combinations of the more simple. And, though it might be improper, without necessity, to multiply beings which they believed to have a real existence, yet, had they seen that ideas are not things that exist, but things that are conceived, they would have appre- hended no danger nor expense from their number. Simple attributes, species and genera, lower or higher, are all things conceived without regard to existence ; they are uni- versals ; they are expressed by general words ; and have an equal title to be called by the name of ideas. I likewise agree with those ancient phi- losophers that ideas are the object, and the sole object, of science, strictly so called — that is, of demonstrative reasoning. And, as ideas are immutable, so their agreements and disagreements, and all their relations and attributes, are immutable. All mathematical truths are immutably true. Like the ideas about which they are conversant, they have no relation to time or place, no dependence upon existence or change. That the angles of a plane tri- angle are equal to two right angles always was, and always will be, true, though no triangle had ever existed. [543] 430 ON THE INTELLECTUAL POWERS £essay VI The same may be said of all abstract truths : on that account they hare often been called eternal truths; and, for the same reason, the Pythagoreans ascribed eternity to the ideas about which they are conversant. They may very properly be called necessary truths ; because it is im- possible they should not be true at all times and in all places. Such is the nature of all truth that can be discovered, by perceiving the agreements and disagreements of ideas, when we take that word in its primitive sense. And that Mr Locke, in his definition of knowledge, had chiefly in his view abstract truths, we may be led to think from the examples he gives to illustrate it. But there is another great class of truths, which are not abstract and necessary, and, therefore, cannot be perceived in the agree- ments and disagreements of ideas. These are all the truths we know concerning the real existence of things — the truth of our own existence — of the existence of other things, inanimate, animal, and rational, and of their various attributes and relations. These truths may be called contingent truths. I except only the existence and attributes of the Supreme Being, which is the only necessary truth I know regarding existence. All other beings that exist depend for their existence, and all that belongs to it, upon the will and power of the first cause ; therefore, neither their existence, nor their nature, nor anything that befalls them, is necessary, but contingent. But, although the existence of the Deity be necessary, I apprehend we can only de- duce it from contingent truths. The only arguments for the existence of a Deity which I am able to comprehend, are ground- ed upon the knowledge of my own existence, and the existence of other finite beings. But these are contingent truths. [544] I believe, therefore, that by perceiving agreements and disagreements of ideas, no contingent truth whatsoever can be known, nor the real existence of anything, not even our own existence, nor the existence of a Deity, which is a necessary truth. Thus I have endeavoured to shew what knowledge may, and what cannot be attained, by per- ceiving the agreements and disagreements of ideas, when we take that word in its primitive sense. We are, in the next place, to consider, whether knowledge consists in perceiving the agreement or disagreement of ideas, taking ideas in any of the senses in which the word is used by Mr Locke and other modern philosophers. 1. Very often the word idea is used so, that to have the idea of anything is a peri, phrasis for conceiving it. In this sense, an idea is not an object of thought, it is thought itself. It is the act of the mind by which we conceive any object. And it is evident that this could not be the meaning which Mr Locke had in view in his definition of knowledge. 2. A second meaning of the word idea is that which Mr Locke gives in the intro- duction to his Essay, when he is making an apology for the frequent use of it : — " It be- ing that term, I think, which serves best to stand for whatsoever is the object of the understanding when a man thinks, or what- ever it is which a man can be employed about in thinking." By this definition, indeed, everything that can be the object of thought is an idea. The objects of our thoughts may, I think, be reduced to two classes. The first class comprehends all those objects which we not only can think of, but which we believe to have a real existence : such as the Creator of all things, and all his creatures that fall within our notice. [545] I oan think of the sun and moon, the earth and sea, and of the various animal, vegetable, and inanimate productions with which it hath pleased the bountiful Creator to enrich our globe. I can think of myself, of my friends and acquaintance. I think of the author of the Essay with high esteem. These, and such as these, are objects of the understanding which we believe to have real existence. A second class of objects of the under- standing which a man may be employed about in thinking, are things which we either believe never to have existed, or which we think of without regard to their existence. Thus, I can think of Don Quixote, of the Island of Laputa, of Oceana, and of Utopia, which I believe never to have ex- isted. Every attribute, every species, and every genus of things, considered abstractly, without any regard to their existence or non-existence, may be an object of the understanding. To this second class of objects of the understanding, the name of idea does very properly belong, according to the primitive sense of the word, and I have already con- sidered what knowledge does and what does not consist in perceiving the agree- ments and disagreements of such ideas. But, if we take the word idea in so ex- tensive a sense as to comprehend, not only the second, but also the first class of objects of the understanding, it will undoubtedly be true that all knowledge consists in per- ceiving the agreements and disagreement* of ideas : for it is impossible that there can be any knowledge, any judgment, any opinion, true or false, which is not employed about the objects of the understanding. But whatsoever is an object of the under- [Sit, SW] obap.iii.] SENTIMENTS CONCERNING JUDGMENT. 431 standing is an idea, according to this second meaning of the word. Yet I am persuaded that Mr Locke, in his definition of knowledge, did not mean that the word idea should extend to all those things which we commonly consider as ob- jects of the understanding. [546] Though Bishop Berkeley believed that sun, moon, and stars, and all material things, are ideas, and nothing but ideas, Mr Locke nowhere professes this opinion. He be- lieved that we have ideas of bodies, but not that bodies are ideas. In like manner, he believed that we have ideas of minds, but not that minds are ideas. When he in- quired so carefully into the origin of all our ideas, he did not surely mean to find the origin of whatsoever may be the object of the understanding, nor to resolve the origin of everything that may be an object of understanding into sensation and reflec- tion. 3. Setting aside, therefore, the two mean- ings of the word idea, before mentioned, as meanings which Mr Locke could not have in his view in the definition he gives of knowledge, the only meaning that could be intended in this place is that which I before called the philosophical meaning of the word idea, which hath a reference to the theory commonly received about the manner in which the mind perceives external obj ects, and in which it remembers and conceives objects that are not present to it. Itis avery ancient opinion, ana has been very generally received among philosophers, that we can- not perceive or think of such objects im- mediately, but by the medium of certain images or representatives of them really existing in the mind at the time. To those images the ancients gave the name of species and phantasms. Modern philosophers have given them the name of idea* " "Tis evident," says Mr Locke, book iv., chap. 4, "themindknows not things immediately, but only by the intervention of the ideas it has of them." And in the same paragraph he puts this question : " How shall the mind, when it perceives nothing but its own ideas, know that they agree with things themselves ?" [547] This theory I have already considered, in treating of perception, of memory, and of conception. The reader will there find the reasons that lead me to think that it has no solid foundation in reason, or in attentive reflection upon those operations of our minds ; that it contradicts the im- mediate dictates of our natural faculties, which are of higher authority than any theory ; that it has taken its rise from the same prejudices which led all the ancient philosophers to think that the Deity could not make this world without some eternal matter to work upon, and which led the [546-548] Pythagoreans and Platonists to think that he could not conceive the plan of the world he was to make without eternal ideas really existing as patterns to work by ; and that this theory, when its necessary consequences are fairly pursued, leads to absolute scep- ticism, though those consequences were not seen by most of the philosophers who have adopted it. I have no intention to repeat what has before been said upon those points ; but only, taking ideas in this sense, to make some observations upon the definition which Mr Locke gives of knowledge. First, If all knowledge consists in per- ceiving the agreements and disagreements of ideas — that is, of representative images of things existing in the mind — it obviously follows that, if there be no such ideas, there can be no knowledge. So that, if there should be found good reason for giving up this philosophical hypothesis, all knowledge must go along with it. I hope, however, it is not so : and that, though this hypothesis, like many others, should totter and fall to the ground, know- ledge will continue to stand firm upon a more permanent basis. [548] The cycles and epicycles of the ancient astronomers were for a thousand years thought absolutely necessary to explain the motions of the heavenly bodies. Yet now, when all men believe them to have been mere fictions, astronomy has not fallen with them, but stands upon a more rational foundation than before. Ideas, or images of things existing in the mind, have, for a longer time, been thought necessary for explaining the operations of the understand- ing. If they should likewise at last be found to be fictions, human knowledge and judgment would suffer nothing by being disengaged from an unwieldy hypothesis. Mr Locke surely did not look upon the ex- istence of ideas as a philosophical hypo- thesis. He thought that we are conscious of their existence, otherwise he would not have made the existence of all our know- ledge to depend upon the existence of ideas. Secondly, Supposing this hypothesis to be true, I agree with Mr Locke that it is an evident and necessary consequence that our knowledge can be conversant about ideas only, and must consist in perceiving their attributes and relations. For nothing can be more evident than this, that all knowledge, and all judgment and opinion, must be about things which are or may be immediate objects of our thought. What cannot be the object of thought, or the object of the mind in thinking, cannot be the object of knowledge or of opinion. Everything we can know of any object, must be either some attribute of the object, or some relation it bears to some other 432 ON THE INTELLECTUAL POWERS. [essay VI. object or objects. By the agreements and disagreements of objects, I apprehend Mr Locke intended to express both their attri- butes and their relations. If ideas then be the only objects of thought, the consequence is necessary, that they must be the only objects of knowledge, and all knowledge must consist in perceiving their agreements and disagreements — that is, their attributes and relations. The use I would make of this conse- quence, is to shew that the hypothesis must be false, from which it necessarily follows. For if we have any knowledge of things that are not ideas, it will follow no less evidently, that ideas are net the only objects of our thoughts. [549] Mr Locke has pointed out the extent and limits of human knowledge, in his fourth book, with more accuracy and judgment than any philosopher had done before ; but he has not confined it to the agreements and disagreements of ideas. And I cannot help thinking that a great part of that book is an evident refutation of the principles laid down in the beginning of it. Mr Locke did not believe that he himself was an idea ; that his friends and acquaint- ance were ideas ; that the Supreme Being, to speak with reverence, is an idea ; or that the sun and moon, the earth and the sea, and other external objects of sense, are ideas. He believed that he had some cer- tain knowledge of all those objects. His knowledge, therefore, did not consist solely in perceiving the agreements and disagree- ments of his ideas ; for, surely, to perceive the existence, the attributes, and relations of things, which are not ideas, is not to per- ceive the agreements and disagreements of ideas- And, if things which are not ideas be objects of knowledge, they must be objects of thought. On the contrary, if ideas be the only objects of thought, there can be no knowledge, either of our own existence, or of the existence of external objects, or of the existence of a Deity. This consequence, as far as concerns the existence of external objects of sense, was afterwards deduced from the theory of ideas by Bishop Berkeley with the clearest evi- dence ; and that author chose rather to adopt the consequence than to reject the theory on which it was grounded. But, with regard to the existence of our own minds, of other minds, and of a Supreme Mind, the Bishop, that he might avoid the consequence, rejected a part of the theory, and maintained that we can think of minds, of their attributes and relations, without ideas. [550] Mr Hume saw very clearly the conse- quences of this theory, and adopted them in his speculative moments ; but candidly acknowledges that, in the common busi- ness of life, he found himself under a neces- sity of believing with the vulgar. Hie " Treatise of Human Nature" is the only system to which the theory of ideas leads ; and, in my apprehension, is, in all its parts, the necessary consequence of that theory. Mr Locke, however, did not see all the consequences of that theory ; he adopted it without doubt or examination, carried along by the stream of philosophers that went before him ; and his judgment and good sense have led him to say many things, and to believe many things, that cannot be re- conciled to it. He not only believed his own existence, the existence of external things, and the existence of a Deity ; but he has shewn very justly how we come by the knowledge of these existences. It might here be expected that he should have pointed out the agreements and dis- agreements of ideas from which these exist- ences are deduced ; but this is impossible, and he has not even attempted it. Our own existence, he observes, we know intuitively; but this intuition is not a percep- tion of the agreement or disagreement of ideas ; for the subject of the proposition, 1 exist, is not an idea, but a person. The knowledge of external objects of sense, he observes, we can have only by sensa- tion. This sensation he afterwards expresses more clearly by the testimony of our senses, which are the proper and sole judges of this thing; whose testimony is the greatest assur- ance we can possibly have, and to which our faculties can attain. This is perfectly agreeable to the common sense of mankind, and is perfectly understood by those who never heard of the theory of ideas. Our senses testify immediately the existence, and many of the attributes and relations of external material beings ; and, by our con- stitution, we rely with assurance upon their testimony, without seeking a reason for doing so. This assurance, Mr Locke ac- knowledges, deserves the name of know- ledge. But those external things are not ideas, nor are their attributes and relations the agreements and disagreements of ideas, but the agreements and disagreements of things which are not ideas. [551] To reconcile this to the theory of ideas, Mr Locke says, That it is the aotual receiv- ing of ideas from without that gives us notice of the existence of those external things. This, if understood literally, would lead us back to the doctrine of Aristotle, that our ideas or species come from without from the external objects, and are the image or form of those objects. But Mr Locke, I believe, meant no more by it, but that our ideas of sense must have a cause, and that we are not the cause of them our- selves. [549-55] 1 chap, in.] SENTIMENTS CONCERNING JUDGMENT. 433 Bishop Berkeley acknowledges all this, and shews very clearly that it does not afford the least shallow of reason for the belief of any material object — nay, that there can be nothing external that has any resemblance to our ideas but the ideas of other minds. It is evident, therefore, that the agree- ments and disagreements of ideas can give us no knowledge of the existence of any material thing. If any knowledge can be attained of things which are not ideas, that knowledge is a perception of agreements and disagreements ; not of ideas, but of things that are not ideas. As to the existence of a deity, though Mr Locke was aware that Des Cartes, and many after him, had attempted to prove it merely from the agreements and disagree- ments of ideas ; yet " he thought it an ill way of establishing that truth, and si- lencing Atheists, to lay the whole stress of so important a point upon that sole founda- tion." And, therefore, he proves this point, with great strength and solidity, from our own existence, and the existence of the sensible parts of the universe. [552] By memory, Mr Locke says, we have the knowledge of the past existence of several things. But all conception of past exist- ence, as well as of external existence, is irreconcileable to the theory of ideas ; be- cause it supposes that there may be imme- diate objects of thought, which are not ideas presently existing in the mind. I conclude, therefore, that, if we have any knowledge of our own existence, or of the existence of what we see about us, or of the existence of a Supreme Being, or if we have any knowledge of things past by memory, that knowledge cannot consist in perceiving the agreements and disagree- ments of ideas. This conclusion, indeed, is evident of itself. For, if knowledge consists solely in the perception of the agreement or disagree- ment of ideas, there can be no knowledge of any proposition, which does not express some agreement or disagreement of ideas ; consequently, there can be no knowledge of any proposition, which expresses either the existence, or the attributes or relations of things, which are not ideas. If, therefore, the theory of ideas be true, there can be no knowledge of anything but of ideas. And, on the other hand, if we have any know- ledge of anything besides ideas, that theory must be false. There can be no knowledge, no judgment or opinion about things which are not im- mediate objects of thought. This I take to be self-evident. If, therefore, ideas be the only immediate objects of thought, they must be the only things in nature of which we can have any knowledge, and about r552-5S4"| which we can have any judgment or opinion. This necessary consequence of the com- mon doctrine of ideas Mr Hume saw, and has made evident in his " Treatise of Human Nature ;" but the use he made of it was not to overturn the theory with which it is necessarily connected, but to overturn all knowledge, and to leave no ground to believe anything whatsoever. If Mr Locke had seen this consequence, there is reason to think that he would have made another use of it. [553] That a man of Mr Locke's judgment and penetration did not perceive a consequence so evident, seems indeed very strange ; and I know no other account that can be given of it but this — that the ambiguity of the word idea has misled him in this, as in several other instances. Having at first defined ideas to be whatsoever is the object of the understanding when we think, he takes it very often in that unlimited sense ; and so everything that can be an object of thought is an idea. At other times, he uses the word to signify certain representative images of things in the mind, which philosophers have supposed to be immediate objects of . thought. At other times, things conceived abstractly, without regard to their exist- ence, are called ideas. Philosophy is much indebted to Mr Locke for his observations on the abuse of words. It is pity he did not apply these observations to the word idea, the ambiguity and abuse of which has very much hurt his excellent Essay. There are some other opinions of philo- sophers concerning judgment, of which I think it unnecessary to say much. Mr Hume sometimes adopts Mr Locke's opinion, that it is the perception of the agreement or disagreement of our ideas ; sometimes he maintains that judgment and reasoning resolve themselves into concep- tion, and are nothing but particular ways of conceiving objects ; and he says, that an opinion or belief may most accurately be defined, a lively idea related to or associated with a present impression. — Treatise of Hu- man Nature, vol. I. page 172- I have endeavoured before, in the first chapterof this Essay, to shew that judgment is an operation of mind specifically distinct from the bare conception of an object. Ihave also considered his notion of belief, in treating of the theories concerning memory. [554] Dr Hartley says — " That assent and dis- sent must come under the notion of ideas, being only those very complex intern a 1 feelings which adhere by association to such clusters of words as are called propositions in general, or affirmations and negations in particular." This, if I understand its meaning, agrees with the opinion of Mr Hume, above mea- 2 F 434 ON THE INTELLECTUAL POWERS. r ESSAY VI, tioned, and lias therefore been before con- sidered. Dr Priestley has given another definition of judgment: — " It is nothing more than the perception of the universal concurrence, or the perfect coincidence of two ideas ; or the want of that concurrence or coinci- dence." This, I think, coincides with Mr Locke's definition, and therefore has been already considered. There are many particulars which deserve to be known, and which might very properly be considered in this Essay on judgment ; concerning the various kinds of propositions by which our judgments are expressed; their subjects and predicates; their con- versions and oppositions : but as these are to be found in every system of logic, from Aristotle down to the present age, I think it unnecessary to swell this Essay with the repetition of what has been said so often. The remarks which have occurred to me upon what is commonly said on these points, as well as upon the art of syllogism ; the utility of the school logic, and the improve- ments that may be made in it, may be found in a " Short Account of Aristotle's Logic, with Remarks," which Lord Kames has honoured with a place in his " Sketches of the History of Man." [555] CHAPTER IV. OP FIRST PRINCIPLES IN GENERAL. One of the most important distinctions of our judgments is, that some of them are intuitive, others grounded on argument. It is not in our power to judge as we will. The judgment is carried along neces- sarily by the evidence, real or seeming, which appears to us at the time. But, in propositions that are submitted to our judgment, there is this great difference — some are of «uch a nature that a man of ripe understanding may apprehend them distinctly, and perfectly understand their meaning, without finding himself under any necessity of believing them to be true or false, probable or improbable. The judg- ment remains in suspense, until it is in- clined to one side or another by reasons or arguments. But there are other propositions which are no sooner understood than they are be- lieved. The judgment follows the appre- hension of them necessarily, and both are equally the work of nature, and the result of our original powers. There is no search- ing for evidence, no weighing of arguments ; the proposition is not deduced or inferred from another ; it has the light of truth in itself, and has no occasion to borrow it from another. Propositions of the last kind, when they are used in matters of science, have com- monly been called axioms ; and on what- ever occasion they are used, are called first principles, principles of common sense, com- mon notions, self-evutent truths. Cicero calls them naiurte judicia, judicia communir bus hominum sensibus infixa. Lord Shaftes- bury expresses them by the words, natural knowledge, fundamental reason, and common sense. [556] What has been said, I think, is sufficient to distinguish first principles, or intuitive judgments, from those which may be as- cribed to the power of reasoning ; nor is it a just objection against this distinction, that there may be some judgments concerning which we may be dubious to which class they ought to be referred. There is a real distinction between persons within the house, and those that are without ; yet it may be dubious to which the man belongs that stands upon the threshold. The power of reasoning — that is, of draw- ing a conclusion from a chain of premises — may with some propriety be called an art. " All reasoning," says Mr Locke, " is search and casting about, and requires pains and application." It resembles the power of walking, which is acquired by use and exercise. Nature prompts to it, and has given the power of acquiring it ; but must be aided by frequent exercise before we are able to walk. After repeated efforts, much stumbling, and many falls, we learn to walk ; and it is in a similar manner that we learn to reason. But the power of judging in self-evidei:t propositions, which are clearly understood, may be compared to the power of swallow- ing our food. It is purely natural, and there- fore common to the learned and the un- learned, to the trained and the untrained. It requires ripeness of understanding, and freedom from prejudice, but nothing else. I take it for granted that there are self- evident principles. Nobody, I think, de- nies it. And if any man were so sceptical as to deny that there is any proposition that is self-evident, I see not how it would be possible to convince him by reasoning. But yet there seems to be great difference of opinions among philosophers about first principles. What one takes to be self-evi- dent, another labours to prove by argu- ments, and a third denies altogether. [557] Thus, before the time of Des Cartes, it was taken for a first principle, that there is a sun and a moon, an earth and sea, which really exist, whether we think of them or not. Des Cartes thought that the exist- ence of those things ought to be proved by argument ; arid in this he has been follow- ed by Malebranche, Arnauld, and Locke. They have all laboured to prove, by very [555-557T eiiAP. iv. j OV FIRST PRINCIPLES IN GENERAL. 435 weak reasoning, the existence of external objects of sense ; and Berkeley and Hume, sensible of the weakness of their arguments, have been led to deny their existence alto- gether. The ancient philosophers granted, that all knowledge must be grounded on first principles, and that there is no reasoning w.thout them. The Peripatetic philosophy was redundant rather than deficient in n st principles. Perhaps the abuse of them in that ancient system may have brought them into discredit in modern times ; for, as the best things may be abused, so that abuse is apt to give a disgust to the thing itself ; and as one extreme often leads into the opposite, this seems to have been the case in the respect paid to first principles in ancient and modern times. Des Cartes thought one principle, express- ed in one word, coyilo, a sufficient foundation for his whole system, and asked no more. Mr Locke seems to think first principles of very small use. Knowledge consisting, according to him, in the perception of the agreement or disagreement of our ideas ; when we have clear ideas, and are able to compare them together, we may always fa- bricate first principles as often as we have occasion for them. Such differences we find among philosophers about first principles. It is likewise a question of some moment, whether the differences among men about first principles can be brought to any issue ? When in disputes one man maintains that to be a first principle which another denies, commonly both parties appeal to common sense, and so the matter rests. Now, is there no way of discussing this appeal ? Is there no mark or criterion, whereby first principles that are truly such, may be dis- tinguished from those that assume the cha- racter without a just title ? I shall humbly offer in the following propositions what appears to me to be agreeable to truth in these matters, always ready to change my opinion upon conviction. [558] 1. First, I hold it to be certain, and even demonstrable, that all knowledge got by reasoning must be built upon first princi- ples.* ( This is as certain as that every house ^ust have a foundation. The power of ,asoning, in this respect, "resembles the nechanical powers or engines ; it must have a fixed point to rest upon, otherwise it spends its force in the air, and produces no effect. When we examine, in the way of ana- lysis, the evidence of any proposition, either we find it self-evident, or it rests upon one or more propositions that support it. The same thing may be said of the propositions * So Aristotle, pturie*. — H. [458. 559] that support it, and of those that support them, as far back as we can go. But we cannot go back in this track to infinity. Where then must this analysis stop ? It is evident that it must stop only when we come to propositions which support all that are built upon them, but are themselves supported by none — that is, to self-evident propositions. Let us again consider a synthetical proof of any kind, where we begin with the premises, and pursue a train of consequences, until we come to the last conclusion or thing to be proved. Here we must begin, either with self-evidentpropositionsorwithsuch as have been already proved. When the last is the case, the proof of the propositions, thus as- sumed, is a part of our proof; and the proof is deficient without it. Suppose then the deficiency supplied, and the proof com- pleted, is it not evident that it must set out with self-evident propositions, and that the whole evidence must rest upon them ? So that it appears to be demonstrable that, without first principles, analytical reasoning could have no end, and synthetical reason- ing could have no beginning ; and that every conclusion got by reasoning must rest with its whole weight upon first princi- ples, as the building does upon its founda- tion. [559] 2. A second proposition is, That some first principles yield conclusions that are certain, others such as are probable, in va- rious degrees, from the highest probability to the lowest. In just reasoning, the strength or weak- ness of the conclusion will always corre- spond to that of the principles on which it is grounded. In a matter of testimony, it is self-evi- dent that the testimony of two is better than that of one, supposing them equal in character, and in their means of knowledge ; yet the simple testimony may be true, and that which is preferred to it may be false. When an experiment has succeeded in several trials, and the circumstances have been marked with care, there is a self-evi- dent probability of its succeeding in a new trial ; but there is no certainty. The pro- bability, in some cases, is much greater than in others ; because, in some cases, it is much easier to observe all the circum- stances that may have influence upon the event than in others. And it is possible that, after many experiments made with care, our expectation may be frustrated in a succeeding one, by the variation of some circumstance that has not, or perhaps could not be observed. Sir Isaac Newton has laid it down as a first principle in natural philosophy, (hat a property which has been found in all bodies upon which we have had access to make ■2F2 433 ON THE INTELLECTUAL POWERS. j essay vi. experiments, and which has always been found in its quantity to be in exact propor- to the quantity of matter in every body, is to be held as an universal property of mat- ter. [560] This principle, as far as I know, has never been called in question. The evi- dence we have, that all matter is divisible, movable, solid, and inert, is resolvable into this principle ; and, if it be not true, we cannot have any rational conviction that all matter has those properties. From the same principle that great man has shewn that we have reason to conclude that all bodies gravitate towards each other. This principle, however, has not that kind of evidence which mathematical axioms have. It is not a necessary truth, whose contrary is impossible ; nor did Sir Isaac ever conceive it to be such. And, if it should ever be found, by just experiments, that there is any part in the composition of some bodies which has not gravity, the fact if duly ascertained, must be admitted as an exception to the general law of gra- vitation. In games of chance, it is a first principle that every side of a die has an equal chance to be turned up ; and that, in a lottery, every ticket has an equal chance of being drawn out. From such first principles as these, which are the best we can have in such matters, we may deduce, by demon- strative reasoning, the precise degree of probability of every event in such games. But the principles of all this accurate and profound reasoning can never yield a certain conclusion, it being impossible to supply a defect in the first principles by any accuracy in the reasoning that is grounded upon them. As water, by its gravity, can rise no higher in its course than the foun- tain, however artfully it be couducted ; so no conclusion of reasoning can have a greater degree of evidence than the first principles from which it is drawn. From these instances, it is evident that, as there are some first principles that yield conclusions of absolute certainty, so there are others that ean only yield probable con- clusions ; and that the lowest degree of probability must be grounded on first prin- ciples as well as absolute certainty.* [561] 3. A third proposition is, That it would contribute greatly to the stability of human knowledge, and consequently to the im- provement of it, if the first principles upon which the various parts of it are grounded were pointed out and ascertained. We have ground to think so, both from facts, and from the nature of the thing. There are two branches of human know- * Compare Stewart's "Elements," ii. p. 38.— H. ledge in which this method has been followed —to wit, mathematics and natural philoso- phy ; in mathematics, as far back as we have books. It is in this science only, that, for more than two thousand years since it be- gan to be cultivated, we find no sects, no contrary systems, and hardly any disputes ; or, if there have been disputes, they have ended as soon as the animosity of par- ties subsided, and have never been again revived. The science, once firmly esta- blished upon the foundation of a few axioms and definitions, as upon a rock, has grown from age so age, so as to become the loftiest and the most solid fabric that human rea- son can boast.* Natural philosophy, till less than two hundred years ago, remained in the same fluctuating state with the other sciences. Every new system pulled up the old by the roots. The system-builders, indeed, were always willing to accept of the aid of first principles, when they were of their side ; but, finding them insufficient to sup- port the fabric which their imagination had raised, they were only brought in as auxi- liaries, and so intermixed with conjectures, and with lame inductions, that their sys- tems were like Nebuchadnezzar's image, whose feet were partly of iron and partly of clay. Lord Bacon first delineated the only so- lid foundation on which natural philoso- phy can be built ; and Sir Isaac Newton reduced the principles laid down by Bacon into three or four axioms, which he calls rpyulce philosnpkandi. From these, toge- ther with the phenomena observed by the senses, which he likewise lays down as first principles, he deduces, by strict rea- soning, the propositions contained in the third book of his "Principia," and in his " Optics ;" and by this means has raised a fabric in those two branches of natural philosophy, which is not liable to be shaken by doubtful disputation, but stands im- movable upon the basis of self-evident principles. [562] This fabric has been carried on by the accession of new discoveries; but is no more subject to revolutions. The disputes about materia prima, sub- stantial forms, Nature's abhorring a vatf 8 * cuum, and bodies having no gravitation in their proper place, are now no more. The builders in this work are not put to the necessity of holding a weapon in one hand while they build with the other ; their whole employment is to carry on the work. Yet it seems to be very probable, that, if natural philosophy had not been rearedupon this solid foundation of self-evident princi- ples, it would have been to this day a field * See Stewart's ■' Elements," ii. p. n— H. [SCO, 562] eiiAi*. iv. OF FIRST P1UNCIPLKS IN GENERAL. 437 or battle, wherein every inch of ground would have been disputed, and nothing fixed and determined. I acknowledge that mathematics and na- tural philosophy, especially the former, have this advantage of most other sciences, that it is less difficult to form distinct and determinate conceptions of the objects about which they are employed ; but, as this difficulty is not insuperable, it affords a good reason, indeed, why other sciences should have a longer infancy ; but no rea- son at all why they may not at last arrive at maturity, by the same steps as those of quicker growth. The facts I have mentioned may there- fore lead us to conclude, that, if in other branches of philosophy the first principles were laid down, as has been done in ma- thematics and natural philosophy, and the subsequent conclusions grounded upon them, this would make it much more easy to dis- tinguish what is solid and well supported from the vain fictions of human fancy. [563] But, laying aside facts, the nature of the thing leads to the same conclusion. For, when any system is grounded upon first principles, and deduced regularly from them, we have a thread to lead us through the labyrinth. The judgment has a distinct and determinate object. The heterogeneous parts being separated, can be examined each by itself. The whole system is reduced to axioms, definitions, and deductions. These are ma- terials of very different nature, and to be measured by a very different standard ; and it is much more easy to judge of each, taken by itself, than to judge of a mass wherein they are kneaded together without distinc- tion. Let us consider how we judge of each of them. First, As to definitions, the matter is very easy. They relate only to words, and differ- ences about them may produce different ways of speaking, but can never produce different ways of thinking, while every man keeps to his own definitions. But, as there is not a more plentiful source of fallacies in reasoning than men's using the same word sometimes in one sense and at other times in another, the best means of preventing such fallacies, or of detecting them when they are committed, is defi- nitions of words as accurate as can be given. Secondly, As to deductions drawn from principles granted on both sides, I do not see how they can long be a matter of dis- pute among men who are not blinded by prejudice or partiality; for the rules of reasoning by which inferences may be drawn from premises have been for two thousand years fixed with great unanimity . No man pretends to dispute tile rules of reasoning [5o3-5u'5~] laid down by Aristotle and repeated by every writer in dialectics. [504] And we may observe by the way, that the reason why logicians have been so una- nimous in determining the rules of reason- ing, from Aristotle down to this day, seems to be, that they were by that great genius raised, in a scientific manner, from a few definitions and axioms. It may farther be observed, that, when men differ about a deduction, whether it follows from certain premises, this I think is always owing to their differing about some first principle. I shall explain this by an example. Suppose that, from a thing having begun to exist, one man infers that it must have had a cause ; another man does not admit the inference. Here it is evident, that the first takes it for a self-evident principle, that everything which begins to exist must liave a cause. The other does not allow this to be self-evident. Let them settle this point, and the dispute will be at an end. Thus, I think, it appears, that, in matters of science, if the terms be properly explained, the first principles upon which the reason- ing is grounded be laid down and exposed to examination, and the conclusions re- gularly deduced from them, it might be expected that men of candour and capacity, who love truth, and have patience to ex- amine things coolly, might come to unani- mity with regard to the force of the deduc- tions, and that their differences might be reduced to those they may have about first principles. 4. A fourth proposition is, That Nature hath not left us destitute of means whereby the candid and honest part of mankind may be brought to unanimity when they happen to differ about first principles. [565] When men differ about things that are taken to be first principles or self-evident truths, reasoning seems to be at an end. Each party appeals to common sense. When one man's common sense gives one deter- mination, another man's a contrary deter- mination, there seems to be no remedy but to leave every man to enjoy his own opinion. This is a common observation, and, I be- lieve, a just one, if it be rightly understood. It is in vain to reason with a man who denies the first principles on which the rea- soning is grounded. Thus, it would be in vain to attempt the proof of a proposition in Euclid to a man who denies the axioms. Indeed, we ought never to reason with men who deny first principles from obstinacy and unwillingness to yield to reason. But is it not possible, that men who really love truth, and are open to conviction, may differ about first principles ? I think it is possible, and that it cannot, without great want of charity, bo denied to be possible- 438 ON THE INTELLECTUAL POWERS. LESSA When this happens, every man who be- lieves that there is a real distinction between truth and error, and that the faculties which God has given us are not in their nature fallacious, must be convinced that there is ii defect or a perversion of judgment on the one side or the other. A man of candour and humility will, in such a case, very naturally suspect his own judgment, so far as to be desirous to enter into a serious examination, even of what he has long held as a first principle. He will think it not impossible, that, although his heart be upright, his judgment may have been perverted, by education, by authority, by party zeal, or by some other of the com- mon causes of error, from the influence of which neither parts nor integrity exempt the human understanding. [5u'G] In such a state of mind, so amiable, and so becoming every good man, has Nature loft him destitute of any rational means by which lie may be enabled, either to correct his judgment if it be wrong, or to confirm it if it be right ? I hope it is not so. I hope that, by the means which nature has furnished, con- troversies about first principles may be brought to an issue, and that the real lovers of truth may come to unanimity with regard \ to them. It is true that, in other controversies, the process by which the truth of a propo- sition is discovered, or its falsehood detected, is, by shewing its necessary connection with first principles, or its repugnancy to them It is true, likewise, that, when the contro- versy is, whether a preposition be itself a first principle, this process cannot be ap- plied. The truth, therefore, in controversies of this kind, labours under a peculiar dis- advantage. But it has advantantages of another kind to compensate this. 1. For, in thejirst place, in such con- troversies, every man is a competent judge; and therefore it is difficult to impose upon mankind. To judge of first principles, requires no more than a sound mind free from preju- dice, and a distinct conception of the question. The learned and the unlearned, the phi- losopher and the day-labourer, are upon a level, and will pass the same judgment, when they are not misled by some bias, or taught to renounce their understanding from some mistaken religious principle. Tn matters beyond the reach of common understanding, the many are led by the few, and willingly yield to their authority. .But, in matters of common sense, the few most yield to the many, when local and trinporary prejudices are removed. No man is now moved by the subtle arguments of Zeno against motion, though, perhaps, he kno.\s not how to answer them. [507 ! The ancient sceptical system furnishes a remarkable instance of this truth. That system, of which Pyrrho'was reputed the father, was carried down, through a succes- sion of ages, by very able and acute philo- sophers, who taught men to believe nothing at all, and esteemed it the highest pitch of human wisdom to withhold assent from every proposition whatsoever. It was sup- ported with very great subtil ty and learning, as we see from the writings of Sextus Eui- piricus, the only author of that sect whose writings have come down to our age. The assault of the sceptics against all science seems to have been managed with more art and address than the defence of the dog- matists. Yet, as this system was an insult upon the common sense of mankind, it died away of itself; and it would be in vain to attempt to revive it. The modern scepticism is very different from the ancient, otherwise it would not have been allowed a hearing ; and, when it has lost the grace of novelty, it will die away also, though it should never be refuted. The modern scepticism, I mean that of Mr Hume, is built upon principles which were very generally maintained by philo- sophers, though they did not see that they led to scepticism. Mr Hume, by tracing, with great acuteness and. ingenuity, the con- sequences of principles commonly received, has shewn that they overturn all knowledge, and at last overturn themselves, and leave the mind in perfect suspense. 2. Secondly, We may observe that opin- ions which contradict first principles, are distinguished, from other errors, by this : — That they are not only false but absurd ; and, to discountenance absurdity, Nature hath given us a particular emotion — to wit, that of ridicule— which seems intended for this very purpose of putting out of counte- nance what is absurd, either in opinion or practice. [568] This weapon, when properly applied, cuts with as keen an edge as argument. Nature hath furnished us with the first to expose absurdity ; as with the last to refute error. Both are well fitted for their several offices, and are equally friendly to truth when pro- perly used. Both may be abused to serve the cause of error ; but the same degree of judgment which serves to detect the abuse of argu- ment in false reasoning, serves to detect the abuse of ridicule when it is wrong directed. Some have, from nature, a happier talent for ridicule than others ; and the same thing holds with regard to the talent of reasoning. Indeed, I conceive there is hardly any absurdity, which, when touched with the pencil of a Lucian, a, Swift, or a Voltaire, would not be put out of counte- nance, when there is not some religious [5uu-5ti8l CIIAP. IV .J OF FIRST PRINCIPLES IN GENERAL. 439 panic, or very powerful prejudice, to blind the understanding. But it must lie acknowledged that the emotion of ridicule, even when most natu- ral, may be stifled by an emotion of a con- trary nature, and cannot operate till that is removed. Thus, if the notion of sanctity is annexed to an object, it is no longer a laughable matter ; and this visor must be pulled off before it appears ridiculous. Hence we see, that notions which appear most ridicu- lous to all who consider them coolly and in- differently, have no such appearance to those who never thought of them but under the impression of religious awe and dread. Even where religion is not concerned, the novelty of an opinion to those who are too fond of novelties ; the gravity and solemnity with which it is introduced ; the opinion we have entertained of the author ; its apparent connection with principles already embraced, or subserviency to in- terests which we have at heart ; and, above all, its being fixed in our minds at that time of life when we receive implicitly what we are taught — may cover its absurdity, and fascinate the understanding for a time. [509] But, if ever we are able to view it naked, and stripped of those adventitious circum- stances from which it borrowed its import- ance and authority, the natural emotion of ridicule will exert its force. An absurdity can be entertained by men of sense no longer than it wears a mask. When any man is found who has the skill or the boldness to pull off the mask, it can no longer bear the light ; it slinks into dark corners for a while, and then is no more heard of, but as an ob- ject of ridicule. Thus I conceive, that first principles, which are really the dictates of common sense, and directly opposed to absurdities in opinion, will always, from the constitu- tion of human nature, support themselves, and gain rather than lose ground among mankind. 3. Thirdly, It may be observed, that, al- though it is contrary to the nature of first principles to admit of direct or apodictical proof; yet there are certain ways of reason- ing even about them, by which those that are just and solid may be confirmed, and those that are false may be detected. It may here be proper to mention some of the topics from which we may reason in matters of this kind. First, It is a good argument ad hommem, if it can be shewn that a first principle which a man rejects, stands upon the same footing with others which he admits : for, when this is the case, he must be guilty of an inconsistency who holds the one and rejects the other. [ 569-571"] Thus the faculties of consciousness, of memory, of external sense, and of reason, are all equally the gifts of nature. No good reason can be assigned for receiving the testimony of one of them, which is not of equal force with regard to the others. The greatest sceptics admit the testimony of consciousness, and allow that what it testi- fies is to be held as a first principle. If, therefore, they reject the immediate testi mony of sense or of memory, they are guilty of an inconsistency. [570] Secondly, A first principle may admit of a proof ad absurdum. In this kind of proof, which is very com- mon in mathematics, we suppose the con- tradictory proposition to be true. We trace the consequences of that supposition in a train of reasoning ; and, if we find any of its necessary consequences to be manifestly absurd, we conclude the supposition from which it followed to be false ; and, there» fore its contradictory to be true. There is hardly any proposition, especially of those that may claim the character of first principles, that stands alone and un- connected. It draws many others along with it in a chain that cannot be broken. He that takes it up must bear the burden of all its consequences ; and, if that is too heavy for him to bear, he must not pretend to take it up. Thirdly, I conceive that the consent of ages and nations, of the learned and un- learned, ought to have great authority with regard to first principles, where every man is a competent judge. Our ordinary conduct in life is built upon first principles, as well as our speculations in philosophy ; and every motive to action supposes some belief. When we find a general agreement among men, in principles that concern human life, this must have great authority with every sober mind that loves truth. It is pleasant to observe the fruitless pains which Bishop Berkeley takes to shew that his system of the non-existence of a material world did not contradict the senti- ments of the vulgar, but those only of the philosophers. With good reason he dreaded more to oppose the authority of vulgar opinion in a matter of this kind, than all the schools of philosophers. [571] Here, perhaps, it will be said. What has authority to do in matters of opinion ? Is truth to be determined by most votes ? Or is authority to be again raised out of its grave to tyrannise over mankind ? I am aware that, in this age, an advo- cate for authority has a very unfavourable plea ; but I wish to give no more tu author- ity than is its due. Most justly do we honour the names of 440 ON THE INTELLECTUAL POWERS. [essay vi. those benefactors to mankind who have con- tributed more or less to break the yoke of that authority which deprives men of the natural, the unalienable right of judging for themselves ; but, while we indulge a just animosity against this authority, and against all who would subject us to its tyranny, let us remember how common the folly is, of going from one faulty extreme into the opposite. Authority, though a very tyrannical mis- tress to private judgment, may yet, on some occasions, be a useful handmaid. This is all she is entitled to, and this is all I plead in her behalf. The justice of this plea will appear by putting a case in a science, in which, of all sciences, authority is acknowledged to have least weight. Suppose a mathematician has made a discovery in that science which he thinks important; that he has put his demonstra- tion in just order ; and, after examining it with an attentive eye, has found no flaw in it, I would ask, Will there not be still in his breast some diffidence, some jealousy, lest the ardour of invention may have made him overlook some false step ? This must bo granted. [572] He commits his demonstration to the ex- amination of a mathematical friend, whom he esteems a competent judge, and waits with impatience the issue of his judgment. Here I would ask again, Whether the verdict of his friend, according as it is favourable or unfavourable, will not greatly increase or d iniiuishh is confidence in hisown judgment? Most certainly it will, and it ought. If the judgment of his friend agree with his own, especially if it be confirmed by two or three able judges, he rests secure of his discovery without farther examination ; but, if it be unfavourable, he is brought back into a kind of suspense, until the part that is suspected undergoes a new and a more rigorous examination. I hope what is supposed in this case is agreeable to nature, and to the experience of candid and modest men on such occa- sions ; yet here we see a man's judgment, even in a mathematical demonstration, con- scious of some feebleness in itself, seeking the aid of authority to support it, greatly strengthened by that authority, and hardly able to stand erect against it, without some new aid. Society in judgment, of those who are esteemed fair and competent judges, has effects very similar to those of civil society : it gives strength and courage to every indi- vidual ; it removes that timidity which is as naturally the companion of solitary judg- ment, as of a solitary man in the state of nature. Let us judge for ourselves, therefore ; but let us not disdain to take that aid from the authority of other competent judges, which a mathematician thinks it necessary to take in that science which, of all sciences, has least to do with authority. In a matter of common sense, every man is no less a competent judge than a mathe- matician is in a mathematical demonstra- tion ; and there must be a great presump- tion that the judgment of mankind, in such a matter, is the natural issue of those facul- ties which God hath given them. Such a judgment can be erroneous only when there is some cause of the error, as general as the error is. When this can be shewn to be the case, I acknowledge it ought to have its due weight. But, to suppose a general devia- tion from truth among mankind in things self-evident, of which no cause can be assigned, is highly unreasonable. [573] perhaps it may be thought impossible to collect the general opinion of men upon any point whatsoever; and, therefore, that this authority can serve us iu no stead in examining first principles. But I appre- hend that, in many cases, this is neither impossible nor difficult. Who can doubt whether men have uni- versally believed the existence of a mate- rial world ? Who can doubt whether men have universally believed that every change that happens in nature must have a cause ? Who can doubt whether men have uni- versally believed, that there is a right and a wrong in human conduct; some things that merit blame, and others that are en- titled to approbation ? The universality of these opinions, and of many such that might be named, is suf- ficiently evident, from the whole tenor of human conduct, as far as our acquaintance reaches, and from the history of all ages and nations of which we have any records. There are other opinions that appear to be universal, from what is common in the structure of all languages- Language is the express image and pic- ture of human thoughts ; and from the picture we may draw some certain conclu- sions concerning the original. We find in all languages the same parts of speech ; we find nouns, substantive and adjective; verbs, active and passive, in their various tenses, numbers, and moods. Some rules of syntax are the same in all languages. Now, what is common in the structure of languages, indicates an uniformity of opinion in those things upon which that structure is grounded. [574] The distinction between substances, and the qualities belonging to them ; between thought and the being that thinks ; be- tween thought and the objects of thought ; is to be found in the structure of all lan- [~57-<2-o7t"l chap, v.] FIRST I'lliNClPLES OF CONTINGENT TRUTHS. 4-11 guages. And, therefore, systems of philo- sophy, which abolish those distinctions, wage war with the common sense of mankind. We are apt to imagine that those who formed languages were no metaphysicians ; but the first principles of all sciences are the dictates of common sense, and lie open to all men ; and every man who has con- sidered the structure of language in a phi- losophical light, will find infallible proofs that those who have framed it, and those who use it with understanding have the power of making accurate distinctions, and of form- ing general conceptions, as well as philoso- phers. Nature has given those powers to all men, and they can use them when occa- sions require it, but they leave it to the philosophers to give names to them, and to descant upon their nature. In like manner, nature has given eyes to all men, and they can make good use of them ; but the struc- ture of the eye, and the theory of vision, is the business of philosophers. Fourthly, Opinions that appear so early in the minds of men that they cannot be the effect of education or of false reason- ing, have a good claim to be considered as fi st principles. Thus, the belief we have, that the persons about us are living and in- telligent beings, is a belief for which, per- haps, we can give some reason, when we are able to reason ; but we had this belief before we could reason, and before we could learn it by instruction. It seems, there- fore, to be an immediate effect of our con- it. tution. The last topic I shall mention is, when an opinion is so necessary in the conduct of life, that, without the belief of it, a man must be led into a thousand absurdities in practice, such an opinion, when we can give no other reason for it, may safely be taken for a first principle. [575] Thus I have endeavoured to shew, that, although first principles are not capable of direct proof, yet differences, that may hap- pen with regard to them among men of candour, are not without remedy ; that Nature has not left us destitute of means by which we may discover errors of this kind ; and that there are ways of reason- ing, with regard to first principles, by which those that are truly such may be distin- guished from vulgar errors or prejudices. CHAPTER V. THE FIRST PRINCIPLES OF CONTINGENT TRUTHS. " Surelv," says Bishop Berkeley, " it is a work well deserving our pains to make a strict inquiry concerning the first princi- ples of knowledge ; to sift and examine [575, 576] them on all sides." What was said in the last chapter is intended both to shew the importance of this inquiry, and to make it more easy. But, in order that such an inquiry may be actually made, it is necessary that the first principles of knowledge be distinguished from other truths, and presented to view, that they may be sifted and examined on all sides. In order to this end, I shall attempt a detail of those I take to be such, and of the reasons why I think them entitled to that character. [67b'] If the enumeration should appear to some redundant, to others deficient, and to others both— if things which I conceive to be first principles, should to others appear to be vulgar errors, or to be truths which derive their evidence from other truths, and there- fore not first principles - in these things every man must judge for himself. I shall rejoice to see an enumeration more perfect in any or in all of those respects ; being persuaded that the agreement of men of judgment' and candour in first principles would be of no less consequence to the ad- vancement of knowledge in general, than the agreement of mathematicians in the axioms of geometry has been to the ad- vancement of that science. The truths that fall within the compass of human knowledge, whether they be self- evident, or deduced from those that are self-evident, may be reduced to two classes. They are either necessary and immutable truths, whose contrary is impossible ; or they are contingent and mutable, depend- ing upon some effect of will and power, which had a beginning, and may have an end. That a cone is the third part of a cylin- der of the same base and the same altitude, is a necessary truth. It depends not upon the will and power of any being. It is im- mutably true, and the contrary impossible. That the sun is the centre about which the earth, and the other planets of our system, perform their revolutions, is a, truth ; but it is nut a necessary truth. It depends upon the power and will of that Being who made the sun and all the planets, and who gave them those motions that seemed best to him. If all truths were necessary truths, there would be no occasion for different tenses in the verbs by which they are expressed. What is true in the present time, w< uld Le true in the past and future ; and there would bo no change or variation of an; thing in nature. We use the present tense in expressing necessary truths; but it is only because there is no flexion of the verb which in- cludes all times. When I say that, three is the half of six, I use the present tense U2 ON THE INTELLECTUAL POWEU5. |_ ESSAY VI. only ; but I mean to express not only what now is, but what always was, and always will be ; and so every proposition is to be under- stood by which we mean to express a neces- sary truth. Contingent truths are of an- other nature. As they are mutable, they may be true at one time, and not at an- other ; and, therefore, the expression of then! must include some point or period of time. [577 J If language had been a contrivance of philosophers, they would probably have given some flexion to the indicative mood of verbs, which extended to all times past, 1 1 resent, and future ; for such a flexion only would .be fit to express necessary proposi- tions, which have no relation to time. But there is no language, as far as I know, in which such a flexion of verbs is to be found. Because the thoughts and discourse of men are seldom employed about necessary truths, hut commonly about such as are contin- gent, languages are fitted to express the List rather than the first. The distinction commonly made between abstract truths, and those that express mat- ters of fact, or real existences, coincides in a great measjre, but not altogether, with that between necessary and contingent truths. The necessary truths that fall within our knowledge are, for the most part, abstract truths. We must except the ex- istence and nature of the Supreme Being, which is necessary. Other existences are the effects of will and power. They had a beginning, and are mutable. Their nature is such as the Supreme Being was pleased to give them. Their attributes and rela- tions must depend upon the nature God has given them, the powers with which he has endowed them, and the situation in which he hath placed them. The conclusions deduced by reasoning from , rst principles, will commonly be ne- cessary or contingent, according as the principles are from which they are drawn. Oa the one hand, I take it to be certain, that whatever can, by just reasoning, be inferred from a principle that is necessary, must be a necessary truth, and that no contingent truth can be inferred from prin- ciples that are necessary. " [578] Thus, as the axioms in mathematics are all necessary truths, so are all the conclu- sions drawn from them ; that is, the whole b dy of that science. But from no mathe- matical truth can we deduce the existence of anything ; not even of the objects of the science. On the other hand, I apprehend there are very few cases in which we can, from principles that are contingent, deduce truths th..t are necessary. I can only recollect * Sec stew irl's '" Elements," li. p 33 one instance of this kind — namely — that, from the existence of things contingent and mutable, we can infer the existence of ail immutable and eternal cause of them. As the minds of men are occupied much more about truths that are contingent than about those that are necessary, I shall first endeavour to point out the principles of the former kind. 1. First, then, I hold, as a first principle, the existence of everything of which I am conscious. Consciousness is an operation of the understanding of its own kind, and cannot be logically defined. The objects of it are our present pains, our pleasures, our hopes, our fears, our desires, our doubts, our thoughts of every kind ; in a word, all the passions, and all the actions and operations of our own minds, while they are present. We may remember them when they are past; but we are conscious of them only while they are present. When a man is conscious of pain, he is certain of its existence; when he is con- scious that he doubts or believes, he is certain of the existence of those operations. But the irresistible conviction he has of the reality of those operations is not the effect of reasoning; it is immediate and intuitive. The existence therefore of those passions and operations of our minds, of which we are conscious, is a first principle, which nature requires us to believe upon her authority. [579] If I am asked to prove that I cannot be deceived by consciousness — to prove that it is not a fallacious sense — I can find nc proof. I cannot find any antecedent truth from which it is deduced, or upon which its evi- dence depends. It seems to disdain any such derived authority, and to claim my assent in its own right. If any man could be found so frantic as to deny that he thinks, while he is conscious of it, I may wonder, I may laugh, or I may pity him, but I cannot reason the matter with him. We have no common principles from which we may reason, and therefore can never join issue in an argument. This, I think, is the only principle of common sense that has never directly been called in question. * It seems to be so firmly rooted in the minds of men, as to retain its authority with the greatest sceptics. Mr Hume, after annihilating body and mind, time and space, action and causation, and even his own mind, acknowledges the reality of the thoughts, sensations, and passions of which he is conscious. * It could not possibly recalled in question. For in doubting the fret or his consciousness, i he sceptic must at leas- affirm the fact of his doubt : but to atfirm a doubt is to affirm the consciousness of it- thetlnu t would, Iheielorc, be self-contradictory— / i\, aniuhi'atc itself. — II. [577-5191 chap. v.J FIRST PRINCIPLES OK CONTINGENT TRUTHS. 443 No philosopher has attempted, by any hypothesis, to account for this consciousness of our own thoughts, and the certain know- ledge of their real existence which accom- panies it. By this they seem to acknow- ledge that this at least is an original power of the mind ; a power by which we not only have ideas, but original judgments, and the knowledge of real existence. I cannot reconcile this immediate know- ledge of the operations of our own minds with Mr Locke's theory, that all know- ledge consists in perceiving the agreement and disagreement of ideas. What are the ideas, from whose comparison the knowledge of our own thoughts results ? Or what are the agreements or disagreements which con- vince a man that he is in pain when he feels it ? [580] Neither can I reconcile it with Mr Hume's theory, that to believe the existence of any- thing, is nothing else than to have a strong and lively conception of it ; or, at most, that belief is only some modification of the idea which is the object of belief. For, not to mention that propositions, not ideas, are the object of belief, in all that variety of thoughts and passions of which we are con- scious we believe the existence of the weak as well as of the strong, the faint as well as the lively. No modification of the opera- tions of our minds disposes us to the least doubt of their real existence. As, therefore, the real existence of our thoughts, and of all the operations and feel- ings of our own minds, is believed by all men — as we find ourselves incapable of doubting it, and as incapable of offering any proof of it — it may justly be considered as a first principle, or dictate of common sense. But, although this principle rests upon no other, n, very considerable and import- ant branch of human knowledge rests upon a. For from this source of consciousness is derived all that we know, and indeed all that we can know, of the structure and of the powers of our own minds ; from which we may conclude, that there is no branch of knowledge that stands upon » firmer foundation ; for surely no kind of evidence can go beyond that of consciousness. How does it come to pass, then, that in this branch of knowledge there are so many and so contrary systems ? so many subtile controversies that are never brought to an issue ? and so little fixed and determined ? Is it possible that philosophers should differ most where they have the surest means of agreement — where everything is built upon a species of evidence which all men ac- quiesce in, and hold to be the most certain ? [581] This strange phaenomenon may, I think, be accounted for, if we distinguish between [580-582] consciousness and reflection, which are often improperly confounded * The first is common to all men at all times j but is insufficient of itself to give us clear and distinct notions of the opera- tions of which we are conscious, and of their mutual relations and minute distinc- tions. The second — to wit, attentive reflec- tion upon those operations, making them objects of thought, surveying them atten- tively, and examining them on all sides — is so far from being common to all men, that it is the lot of very few. The greatest part of men, either through want of capacity, or from other causes, never reflect attentively upon the operations of their own minds. The habit of this reflection, even in those whom nature has fitted for it, is not to be at- tained without much pains and practice. We can know nothing of the immediate objects of sight, but by the testimony of our eyes; and I apprehend that, if mankind had found as great difficulty in giving at- tention to the objects of sight, as they find in attentive reflection upon the operations of their own minds, our knowledge of the first might have been in as backward a state as our knowledge of the last. But this darkness will not last for ever. Light will arise upon this benighted part of the intellectual globe. When any man is so happy as to delineate the powers of the human mind as they really are in nature, men that are free from prejudice, and cap- able of reflection, will recognise their own features in the picture ; and then the wonder will be, how things so obvious could be so long wrapped up in mystery and darkness ; how men could be carried away by false theories and conjectures, when the truth was to be found in their own breasts if they had but attended to it. 2. Another first principle, I think, is, That the thoughts of which I am contci >vs, are the tho-ights of a being which I call myself, my mind, mi/ person. [582] The thoughts and feelings of which we are conscious are continually changing, and the thought of this moment is not the thought of the last ; but something which I call my. self, remains under this change of thought. This self has the same relation to all the successive thoughts I am conscious of — they are all my thoughts; and every thought which is not my thought, must be the thought of some other person. If any man asks a proof of this, I confess I can give none ; there is an evidence in the proposition itself which I am unable to re- sist. Shall I think that thought can stand by itself without a thinking being ? or that ideas can feel pleasure or pain ? My nature dictates to me that it is impossible. * t'oinjiarc aluve, pp. .230, b, 258, a— H. 444 ON THE INTELLECTUAL POWERS. Lessay yi And that nature has dictated the same to all men, appears from the structure of all languages : for in all languages men have expressed thinking, reasoning, willing, lov- ing, hating, by personal verbs, which, from their nature, require a person who thinks, reasons, wills, loves, or hates. From which it appears, that men have been taught by nature to believe that thought requires a thinker, reason a reasoner, and love a lover. Here we must leave Mr Hume, who con- ceives it to be a vulgar error, that, besides the thoughts we are conscious of, there is a mind which is the subject of those thoughts. If the mind be anything else than impres- sions and ideas, it must be a word without a meaning. The mind, therefore, accord- ing to this philosopher, is a word which signifies a bundle of perceptions ; or, when he defines it more accurately — " It is that succession of related ideas and impressions, of which we have an intimate memory and consciousness.'* I am, therefore, that succession of related ideas and impressions of which I have the intimate memory and consciousness. But who is the I that has this memory and consciousness of a succession of ideas and impressions ? Why, it is nothing but that succession itself. [583] Hence, I learn, that this succession of ideas and impressions intimately remembers, and is conscious of itself. I would wish to be farther instructed, whether the impres- sions remember and are conscious of the ideas, or the ideas remember and are con- scious of the impressions, or if both remem- ber and are conscious of both ? and whether the ideas remember those that come after them, as well as those that were before them ? These are questions naturally arising from this system, that have not yet been explained. This, however, is clear, that this succes- sion of ideas and impressions, not only re- members and is conscious, but that it judges, reasons, affirms, denies — nay, that it eats and drinks, and is sometimes merry and sometimes sad. If these things can be ascribed to a suc- cession of ideas and impressions, in* a con- sistency with common sense, I should be very glad to know what is nonsense. The scholastic philosophers have been wittily ridiculed, by representing them as disputing upon thisquestion — Numchimcera bnmbinans in vacuo possit comedere secun- das iiitentiane.i ? and I believe the wit of man cannot invent a more ridiculous ques- tion. But, if Mr Hume's philosophy be admitted, this question deserves to be treuted more gravely : for if, as we learn from this philosophy, a succession of ideas and impressions may eat, and drink, and be merry, I see no good reason why a chimera, which,, if not the same is of kin to an idea, may not chew the cud upon that kind of food which the schoolmen call second intentions." 3. Another first principle I take to be — Thai- those things did really/ happen which 1 distinc ly- remember. [584] This has one of the surest marks of a first principle ; for no man ever pretended to prove it, and yet no man in his wits calls it in question : the testimony of memory, like that of consciousness, is immediate ; it claims our assent upon its own authority. -f Suppose that a learned counsel, in defence of a client against the concurring testimony of witnesses of credit, should insist upon a new topic to invalidate the testimony. " Admitting," says he, " the integrity of the witnesses, and that they distinctly re- member what they have given in evidence — it does not follow that the prisoner is guilty. It has never been proved that the most distinct memory may not be fallacious. Shew me any necessary connection between that act of the mind which we call memory, and the past existence of the event remem- bered. No man has ever offered a shadow of argument to prove such a connection ; yet this is one link of the chain of proof against the prisoner ; and, if it have no strength, the whole proof falls to the ground : until this, therefore, be made evident — until it can be proved that we may safely rest upon the testimony of memory for the truth of past events — no judge or jury can justly take away the life of a citizen upon so doubtful a point.** I believe we may take it for granted, that this argument from a learned counsel would have no other effect upon the judge or jury, than to convince them that he was dis- ordered in his judgment. Counsel is allowed to plead every. hing for a client that is fit to persuade or to move ; yet I believe no counsel ever had the boldness to plead this topic. And for what reason ? For no other reason, surely, but because it is absurd. Now, what is absurd at the bar, is so in the philosopher's chair. What would be ridi- culous, if delivered to a jury of honest sen- sible citizens, is no less so when delivered gravely in a philosophical dissertation. Mr Hume has not, as far as I remember, directly called in question the testimony of * All this criticism of Hume proceeds upon the erroneous hypothesis that he was a Dogmatist He was a Sceptic— that is, he accepted the principles as- serted by the prevalent Dogmatism ; and only shewed that such and such conclusions were, on these -prin- ciples, inevitable. The absurdity was not Hume's, but Locke's. This is the kind of criticism, however, with which Hume is generally assailed H. + The datum of Memory does not stand uponjhe same ground as the datum of simple Consciousness. In so Far as memory' is consciousness, it cannot he denied Wc cannot, without contradiction, ik'liy the fact of memory as a present coniciousnets j but we may, without contradiction, suppose that the past given therein, is only an illusion of the present H. f 583, 584T ohap. v.] FIRST PRINCIPLES OF CONTINGENT TRUTHS. 44tt memory ; but he has laid down the premises by which its authority is overturned, leav- ing it to his reader to draw the conclu- sion. [585] He labours to shew that the belief or assent which always attends the memory and senses is nothing but the vivacity of those perceptions which they present. He shews very clearly, that this vivacity gives no ground to believe the existence of ex- ternal objects. And it is obvious that it can give as little ground to believe the past existence of the objects of memory. Indeed the theory concerning ideas, so generally received by philosophers, destroys all the authority of memory, as well as the authority of the senses. Des Cartes, Ma- lebranche, and Locke, were aware that this theory made it necessary for them to find out arguments to prove the existence of ex- ternal objects, which the vulgar believe upon the bare authority of their senses ; but those philosophers were not aware that this theory made it equally necessary for them to find arguments to prove the exist- ence of things past, which we remember, and to support the authority of memory. All the arguments they advanced to sup- port the authority of our senses, were easily refuted by Bishop Berkeley and Mr Hume, being indeed' very weak and inconclusive. And it would have been as, easy to answer every argument they could have brought, consistent with their theory, to support the authority of memory. For, according to that theory, the im- mediate object of memory, as well as of every other operation of the understanding, is an idea present in the mind. And, from the present existence of this idea of me- mory I am left to infer, by reasoning, that, six months or six years ago, there did ex- ist an object similar to, this idea. [586] But what is there in the idea that can lead me to this conclusion ? What mark does it bear of the date of its archetype ? Or what evidence have T that it had an archetype, and that it is not the first of its Mnd? Perhaps it will be said, that this idea or image in the mind must have had a cause. I admit that, if there is such an image in the mind, it must have had a cause, and a cause able to produce the effect ; . but what can we infer from its having a cause ? Does it follow that the effect is a type, an image, a copy of its cause ? Then it will follow, that a picture is an image of the painter, and a coach of the coachmaker. A past event may be known by reasoning ; but that is not remembering it. When I remember a thing distinctly, I disdain equally to hear reasons for it or against it. And so I think does every man in his senses. rS85-S87'l 4. Another first principle is, Our own per- sonal identity and continued existence, as far baek as we remember anything distinctly. This we know immediately, and not by reasoning. It seems, indeed, to be a part of the testimony of memory. Every- thing we remember has such a relation to ourselves as to imply necessarily our ex- istence at the time remembered. And there cannot be a more palpable absurdity than that a man should remember what happened before he existed. He must therefore have existed as far back as he re- members anything distinctly, if his memory be not fallacious. This principle, there- fore, is so connected with the last mention- ed, that it may be doubtful whether both ought not to be included in one. Let eve"ry one judge of this as he'sees reason. The proper notion of identity, and the sen- timents of Mr Locke on this subject, have been considered before, under the head of Memory. [587] 5. Another first principle is, That those things do really exist which we distinctly perceive by oitr senses, and are wfiat we perceive them to le. It is too evident to need proof, that all men are by nature led to give implicit faith to the distinct testimony of their senses, long before they are capable of any bias from prejudices of education or of philo- sophy. How came we at first to know that there are certain beings about us whom we call father, and mother, and sisters, and bro- thers, and nurse ? Was it not by the testimony of our senses ? How did these persons convey to us any information or instruction ? Was it not by means of our senses ? It is evident we can have no communi- cation, no correspondence or society with any created being, but by means of our senses. And, until we rely upon their testi- mony, we must consider ourselves as being alone in the universe, without any fellow- creature, living or inanimate, and be left to converse with our own thoughts. Bishop Berkeley surely did not duly con- sider that it is by means of the material world that we have any correspondence with thinking beings, or any knowledge of their existence ; and that, by depriving us of the material world, he deprived us, at the same time, of family, friends, country, and every human creature ; of every object of affection, esteem, or concern, except our selves. The good Bishop surely never intended this. He was too warm a friend, too zeal- ous a patriot, and too good a Christian to be capable of such a thought. He was not aware of the consequences of his system, and therefore they ought not to be imputed 446 ON THE INTELLECTUAL POWERS. j_ESSA to him ; but we must impute them to the system itself. It stifles every generous and social principle. [588] When I consider myself as speaking to men who hear me, and can judge of what I say, I feel that respect which is due to such an audience. I feel an enjoyment in a reciprocal communication of sentiments with candid and ingenious friends ; and my soul blesses the Author of my being, who has made me capable of this manly and rational entertainment. But the Bishop shews me, that this is all a dream ; that I see not a human face ; that all the objects I see, and hear, and handle, are only the ideas of my own mind ; j ideas are my only companions. Cold com- pany, indeed ! Every social affection freezes at the thought ! But, my Lord Bishop, are there no minds left in the universe but my own ? Yes, indeed; it is only the material world that is annihilated ; everything else remains as it was. This seems to promise some comfort in my forlorn solitude. But do I see those minds ? No. Do I see their ideas ? No. Nor do they see me or my ideas. They are, then, no more to me than the inhabit- ants of Solomon's isles, or of the moon ; and my melancholy solitude returns. Every social tie is broken, and every social affec- tion is stifled. This dismal system, which, if it could be believed, would deprive men of every social comfort, a very good Bishop, by strict and accurate reasoning, deduced from the prin- ciples commonly received by philosophers concerning ideas. The fault is not in the reasoning, but in the principles from which it is drawn. All the arguments urged by Berkeley and Hume, against the existence of a material world, are grounded upon this principle — that we do not perceive external objects themselves, but certain images or ideas in our own minds."' But this is no dictate of common sense, but directly contrary to the sense of all who have not been taught it by philosophy. [589] We have before examined the reasons given by philosophers to prove that ideas, and not external objects, are the immediate objects of perception, and the instances given to prove the senses fallacious. With- out repeating what has before been said upon those points, we shall only here ob- serve, that, if external objeets be perceived immediately, we have the same reason to * Idealism, as already noticed, rests equally well, if not better, on the hypothesis that what we perceive (or are conscious of in perception) is only a modifica. tion of mind, as on the hypothesis that, in perception, we are conscious of a representative. entity distinct from mind as from the external reality. — H. believe their existence as philosophers have to believe the existence of ideas, while they hold them to be the immediate objects of perception." 6. Another first principle, I think, is, That we have some degree of power over Our actions, and the determinations of our will. All power must be derived from th« fountain of power, and of every good »ift- Upon His good pleasure its continuance de- pends, and it is always subject to his con- trol. Beings to whom God has given any de- gree of power, and understanding to direct them to the proper use of it, must be ac- countable to their Maker. But those who are intrusted with no power can have no account to make ; for all good conduct con- sists in the right use of power; all bad conduct in the abuse of it. To call to account a being who never was intrusted with any degree of power, is an absurdity no less than it would be to call to account an inanimate being. We are sure, therefore, if we have any account to make to the Author of our being, that we must have some degree of power, which, as far as it is properly used, entitles us to his approbation ; and, when abused, renders us obnoxious to his displeasure. [590] It is not easy to say in what way we first get the notion or idea of power. It is neither an object of sense nor of conscious- ness. We see events, one succeeding an- other ; but we see not the power by which they are produced. We are conscious of the operations of our minds ; but power is not an operation of mind. If we had no notions but such as are furnished by the external senses, and by consciousness, it seems to be impossible that we should ever have any conception of power. Accord- ingly, Mr Hume, who has reasoned the most accurately upon this hypothesis, denies that we have any idea of power, and clearly refutes the account given by Mr Locke of the origin of this idea. But it is in vain to reason from a hypo- thesis against a. fact, the truth of which every man may see by attending to his own thoughts. It is evident that all men, very early in life, not only have an idea of power, but a conviction that they have some de- gree of it in themselves ; for this conviction is necessarily implied in many operations of mind, which are familiar to every man, and without which no man can act the part of a reasonable being. First, It is implied in every act of voli- tion. " Volition, it is plain," says Mr Locke, " is an act of the mind, knowingly * Philosophers admitted that we are conscious 61 these ; does Reid admit this of external objects ?— H. [S88-S90 AHAP. v.] FIRST PRINCIPLES OF CONTINGEN'I TRUTHS. 447 exerting that dominion which it takes itself to have over any part of the man, by em- ploying it in, or withholding it from any particular action." Every volition, there- fore, implies a conviction of power to do the action willed. A man may desire to make a visit to the moon, or to the planet Jupi- ter ; but nothing but insanity could make him will to do so. And, if even insanity produced this effect, it must be by making him think it to be in his power. Secondly, This- conviction is implied in all deliberation ; for no man in his wits de- liberates whether he shall do what he be- lieves not to be in his power. Thirdly, The same conviction is implied in every resolution or purpose formed in consequence of deliberation. A man may as well form a resolution to pull the moon oat of her sphere, as to do the most insignificant action which he believes not to be in his power. The same thing may be said of every pro- mise or contract wherein a man plights his faith ; for he is not an honest man who promises what he does not believe he has power to perform. [591] As these operations imply a, belief of some degree of power in ourselves ; so there are others equally common and familiar, which imply a like belief with regard to others. When we impute to a man any action or omission, as a ground of approbation or of blame, we must believe he had power to do otherwise. The same is implied in all advice, exhortation, command, and rebuke, and in every case in which we rely upon his fidelity in performing any engagement or executing any trust It is not more evident that mankind have a conviction of the exis ence of a material world, than that they have the conviction of some degree of power in themselves and in others ; every one over his own actions, and the determinations of his will — a con- viction so early, so general, and so inter- woven with the whole of human conduct, that it must be the natural effect of our constitution, and intended by the Author of our being to guide our actions. It resembles our conviction of the ex- istence of a material world in this respect also, that even those who reject it in specu- lation, find themselves under a necessity of being governed by it in their practice ; and thus it will always happen when philosophy contradicts first principles, 7. Another first principle is — That the natural faculties, by which we distinguish truth from error, are not fallacious. If any man should demand a proof of this, it is impossible to satisfy him. For, suppose it should be mathematically demonstrated, this would signify nothing in this case; because, to judge of a demonstration, a man [591-5931 must trust his faculties, and take for gran ted the very thing in question. [592] If a man's honesty were called in ques- tion, it would be ridiculous to refer it to the man's own word, whether he be honest or not. The same absurdity there is in at- tempting to prove, by any kind of reasoning, probable or demonstrative, that our reason is not fallacious, since the very point in question is, whether reasoning may be trusted. If a sceptic should build his scepticism upon this foundation, that all our reasoning and judging powers are fallacious in their nature, or should resolve at least to with- hold assent until it be proved that they are not, it would be impossible by argument to beat him out of this stronghold ; and lie must even be left to enjoy his scepticism. Des Cartes certainly made a false step in this matter, for having suggested this doubt among others — that whatever evidence he might have from his consciousness, his senses, his memory, or his reason, yet possibly some malignant being had given him those faculties on purpose to impose upon him ; and, therefure, that they are not to be trusted without a proper voucher. To remove this doubt, he endeavours to prove the being of a Deity who is no de- ceiver; whence he concludes, that the facul- ties he had given him are true and worthy to be trusted. It is strange that so acute a reasoner did not perceive that in this reasoning there is evidently a begging of the question. For, if our faculties be fallacious, why may they not deceive us in this reasoning as well as in others ? And, if they are not to be trusted in this instance without a voucher, why not in others ? [593] Every kind of reasoning for the veracity of our faculties, amounts to no more than taking their own testimony for their vera- city ; and this we must do implicitly, until God give us new faculties to sit in judg- ment upon the old ; and the reason why Des Cartes satisfied himself with so weak an argument for the truth of his faculties, most probably was, that he never seriously doubted of it. If any truth can be said to be prior to all others in the order of nature, this seems to have the best claim-; because, in every instance of assent, whether upon intuitive, demonstrative, or probable evidence, the truth of our faculties is taken for granted, and is, as it were, one of the premises on which our assent is grounded.* How then come we to be assured of this * There is a presumption in favour of the veracity of the primary data of consciousness. This can only be rebutted by shewingtha' these facts are contradic. tory. Scepticism attempts to shew ti is on the priii. ciplcs which Dogmatism postulates — 11. 448 ON THE INTELLECTUAL POWERS. £ESSAY VI. fundamental truth on which all others rest ? Perhaps evidence, as in many other respects it resembles light, so in this also — that, as light, which is the discoverer of all visible objects, discovers itself at the same time, so evidence, which is the voucher for all truth, vouches for itself at the same time. This, however, is certain, that such is the constitution of the human mind, that evidence discerned by us, forces a corre- sponding degree of assent. And a man who perfectly understood a just syllogism, without believing that the conclusion follows from the premises, would be a greater mon- ster than a man bom without hands or feet. We are born under a necessity of trust- ing to our reasoning and judging powers ; anU a real belief of their being fallacious cannot be maintained for any considerable time by the greatest sceptic, becaube it is doing violence to our constitution. It is like a man's walking upon hi hands, a feat which some men upon occasion can exhibit; but no man ever made a long journey in this manner. Cease to admire his dexte- rity, and he will, like other men, betake himself to his legs. [594 ] We may here take notice of a property of the principle under consideration, that seems to be common to it with many other first principles, and which can hardly be found in any principle that is built solely upon reasoning ; and that is, that in most men it produces its effect without ever being attended to, or made an object of thought. No man ever thinks of this principle, unless whenhecousidersthe grounds of scepticism ; yet it invariably governs his opinions. When a man in the common course of life gives credit to the testimony of his senses, his memory, or his reason, he does not put the question to himself, whether these faculties may deceive him ; yet the trust he reposes in them supposes an inward conviction, that, in that instance at least, they do not deceive him. It is another property of this and of many first principles, that they force assent in par- ticular instances, more powerfully than when they are turned into a general propo- sition. Many sceptics have denied every general principle of science, excepting per- haps the existence of our present thoughts ; yet these men reason, and refute, and prove, they assent and dissent in particular cases. They use reasoning to overturn all reason- ing, and judge that they ought to have no judgment, and see clearly that they are blind. Many have in general maintained that the senses are fallacious, yet there never was found a man so sceptical as not to trust his senses in particular instances when his safety required it ; and it may be observed of those who have professed scep- ticism, that their scepticism lies in generals, while in particulars they are no less dog- matical than others. 8. Another first principle relating to ex- istence, is, That Ihrre is. life and intelligence in our. fellow-men withwhomwe converse. As soon as children are capable of asking a question, or of answering a question, as soon as they shew the signs of love, of re- sentment, or of any other affection, they must be convinced that those with whom they have this intercourse are intelligent beings. [595] It is evident they are capable of such in- tercourse long before they can reason. Every one knows that there is a social in- tercourse between the nurse and the child before it is a year old. It can, at that age, understand many things that are said to it. It can by signs ask and refuse, threaten and supplicate. It clings to its nurse in danger, enters into her grief and joy, is hap- py in her soothing and caresses, and un- happy in her displeasure. That these tilings cannot be without a conviction in the child that the nurse is an intelligent being, I think must be granted. Now, I would ask how a child of a year old comes by this conviction ? Not by rea- soning surely, for children do not reason at that age. Nor is it by external senses, for life and intelligence are not objects of the external senses. By what means, or upon what occasions, Nature first gives this information to the infant mind is not easy to determine. We are not capable of reflecting upon our own thoughts at that period of life ; and before we attain this capacity, we have quite for- got how or on what occasion we first had this belief ; we perceive it in those who are born blind, and in others who are born deaf ; and therefore Nature has not con- nected it solely either with any object of sight, or with any object of hearing. When we grow up to the years of reason and re- flection, this belief remains. No man thinks of asking himself what reason he has to be- lieve that his neighbour is a living creature- He would be not a little surprised if another person should ask him so absurd a ques- tion ; and perhaps could not give any rea- son which would not equally prove a watch or a puppet to be a living creature. But, though you should satisfy him of the weakness of the reasons he gives for his be- lief, you cannot make him in the least doubtful. This belief stands upon another foundation than that of reasoning; and therefore, whether a man can give good reasons for it or not, it is not in his power to shake it off. [590] Setting aside this natural conviction, I believe the best reason we can give, to prove that other men are living and intelli- [>94-59GT chap, v.] FIRST PRINCIPLES OF CONTINGENT TRUTHS 449 gent, is, that their words and actions indi- cate like powers of understanding as we are conscious of in ourselves. The very same argument applied to the works of na- ture, leads us to conclude that there is an intelligent Author of nature, and appears equally strong and obvious in the last case as in the first ; so that it may be doubted whether men, by the mere exercise of rea- soning, might not as soon discover the ex- istence of a Deity, as that other men have life and intelligence. The knowledge of the last is absolutely necessary to our receiving any improve- ment by means of instruction and example ; and, without these means of improvement, there is no ground to think that we should ever be able to acquire the use of our rea- soning powers. This knowledge, therefore, must be antecedent to reasoning, and there- fore must be a first principle. It cannot be said that the judgments we form concerning life and intelligence in other beings are at first free from error. But the errors of children in this matter he on the safe side ; they are prone to at- tribute intelligence to things inanimate. These errors are of small consequence, and are gradually corrected by experience and ripe judgment. But the belief of life and intelligence in other men, is absolutely ne- cessary for us before we are capable of reasoning ; and therefore the Author of our being hath given us this belief antece- dently to all reasoning. 9. Another first principle I take to be, That certain features of the countenance, sounds of the voice, and gestures of the body, indicate certain thoughts and dispositions tf mind. [597] That many operations of the mind have their natural signs in the countenance, voice, and gesture, I suppose every man will ad- mit. Omnis evim moius animi, says Cicero, suum quemdam habet a nalura vultum, et vocem et gestum. The only question is, whether we understand the signification of those signs, by the constitution of our na- ture, by a kind of natural perception simi- lar to the perceptions of sense ; or whether we gradually learn the signification of such signs from experience, as we learn that smoke is a sign of fire, or that the freezing of water is a sign of cold ? I take the first to be the truth- It seems to me incredible, that the no- tions men have of the expression of features, voice, and gesture, are entirely the fruit of experience. Children, almost assoonas born, may be frighted, and thrown into fits by a threatening or angry tone of voice. I knew a man who could make an infant cry, by whistling a melancholy tune in the same or in the next room ; and again, by alter- ing his key, and the strain of his music, [597, 598] could make the child leap and dance for joy. It is not by experience surely that we learn the expression of music ; for its opera- tion is commonly strongest the first time we hear it; On» air expresses mirth and festi- vity — so that, when we hear it, it is with difficulty we can forbear to dance ; another is sorrowful and solemn. One inspires with tenderness and love ; another with rage and fury. " Hear how Timotheus varied lays surprise, And bid alternate passions fall and rise ; While at each change, the son of Lvbian Jove Now burns with glory, and then melts with love. Now his tierce eyes with sparkling fury glow, Now sighs ste:il out, and tears begin 1o flow. Persians and Greeks, like turns of Nature, found, And the world's victor stood suUdu'd by sound." It is not necessary that a man have studied either music or the passions, in order to his feeling these effects. The most ignorant and unimproved, to whom Nature has given a good ear, feel them as strongly as the most knowing. [598] The countenance and gesture have an expression no less strong and natural than the voice. The first time one sees a stern and fierce look, a contracted brow, and a menacing posture, he concludes that the person is inflamed with anger. Shall we say, that, previous to experience, the most hostile countenance has as agreeable an appearance as the most gentle and benign ? This surely would contradict all experience ; for we know that an angry countenance will fright a child in the cradle. Who has not observed that children, very early, are able to distinguish what is said to them in jest from what is said in earnest, by the tone of the voice, and the features of the face ? They judge by these natural signs, even when they seem to contradict the arti- ficial. If It were by experience that we learn the meaning of features, and sound, and gesture, it might be expected that we should recollect the time when we first learned those lessons, or, at least, some of such a multitude. Those who give attention to the opera- tions of children, can easily discover the time when they have their earliest notices from experience— such as that flame will burn, or that knives will cut. But no man is able to recollect in himself, or to observe in others, the time when the expres- sion of the face, voice, and gesture, were learned. Nay, I apprehend that it is impossible that this should be learned from experi- ence. When we see the sign, and see the thing signified always conjoined with it, expe- rience may be the instructor, and teach us how that sign is to be interpreted. But 2 J rt is impos- sible that anything should have its origin without a cause." — TiM£;us. I believe Mr Hume was the first who ever held the contrary.' This, indeed, he avows, and assumes the honour of the dis- covery. " It is," says he, " a maxim in philosophy, that whatever begins to exist, must have a cause of existence. This is commonly taken for granted in all reason- ings, without any proof given or demanded. It is supposed to be founded on intuition, and to be one of those maxims which, though they may be denied with the lips, it is impossible for men in their hearts really to doubt of. But, if we examine this maxim by the idea of knowledge above explained, we shall discover in it no mark of such intuitive certainty." The meaning of this seems to be, that it did not suit with his theory of intuitive certainty, and, there- fore, he excludes it from that privilege. The vulgar adhere to this maxim as firmly and universally as the philosophers. Their superstitions have the same origin as the systems of philosophers — to wit, a desire to know the causes of things. Felix qui potuit rerum cognoscere causas, is the universal sense of men ; but to say that anything can happen without a cause, shocks the common sense of a savage. This universal belief of mankind is easily accounted for, if we allow that the neces- sity of a cause of every event is obvious to the rational powers of a man. But it is impossible to account for it otherwise. It * See last note. — H [617, 6 IS] chap vi.J FIRST PRINCIPLES OF NECESSARY TRUTHS. 457 cannot be ascribed to education, to systems of philosophy, or to priestcraft. One would think that a philosopher who takes it to be a general delusion or prejudice, would endeavour to shew from what causes in human nature such a general error may take its rise. But I forget that Mr Hume might answer upon his own principles, that since things may happen without a cause — this error and delusion of men may be uni- versal without any cause. [619] 2. A second reason why I conceive this to be a first principle, is, That mankind not only assent to it in speculation, but that the practice of life is grounded upon it in the most important matters, even in cases where experience leaves us doubtful ; and it is impossible to act with common prudence if we set it aside. In great families, there are so many bad things done by a cerlain personage, called Nobody, that it is proverbial that there is a Nobody about every house who does a. great deal of mischief ; and even where there is the exactest inspection and govern- ment, many events will happen of which no other author can be found ; so that, if we trust merely to experience in this matter, No- body will be found to be a very active person, and to have no inconsiderable share in the management of affairs. But whatever coun- tenance this system may have from experi- ence, it is too shocking to common sense to impose upon the most ignorant. A child knows that, when his top, or any of his play- things, are taken away, it must be done by somebody. Perhaps it would not be diffi- cult to persuade him that it was done by some invisible being, but that it should be done by nobody he cannot believe. Suppose a man's house to be broke open, his money and jewels taken away. Such things have happened times innumerable without any apparent cause ; and were he only to reason from experience in such a case, how must he behave ? He must put in one scale the instances wherein a cause was found of such an event, and in the other scale the instances where no cause was found, and the preponderant scale must determine whether it be most probable that there was a, cause of this event, or that there was none. Would any man of com- mon understanding have recourse to such an expedient todirecthisjudgment? [620] Suppose a man to be found dead on the highway, his skull fractured, his body pierced with deadly wounds, his watch and money carried off. The coroner's jury sits upon the body ; and the question is put, What was the cause of this man's death ? — was it accident, or felo de se, or murder by persons unknown ? Let us suppose an adept in Mr Hume's philosophy to make one of the jury, and that he insists upon the [619-621] previous question, whether there was any cause of the event, and whether it happened without a cause. Surely, upon Mr Hume's principles, a great deal might be said upon this point ; and, if the matter is to be determined by past experience, it is dubious on which side the weight of argument might stand. But we may venture to say, that, if Mr Hume had been of such a jury, he would have laid aside his philosophical principles, and acted according to the dictates of common pru- dence. Many passages might be produced, even in Mr Hume's philosophical writings, i/i which he, unawares, betrays the same in- ward conviction of the necessity of causes which is common to other men. I shall mention only one, in the " Treatise of Hu- man Nature," and in that part of it where he combats this very principle : — " As to those impressions," says he, " which arise from the senses, their ultimate cause is, in my opinion, perfectly inexplicable by hu- man reason ; and it will always be impos- sible to decide with certainty whether they arise immediately from the object, or are produced by the creative power of the mind, or are derived from the Author of our being." ■ Among these alternatives, he never thought of their not arising from any cause.' [621] The arguments which Mr Hume offers to prove that this is not a self-evident prin- ciple, are three. First, That all certainty arises from a comparison of ideas, and a discovery of their unallerable relations, none of which relations imply this proposi- tion, That whatever has a beginning must have a cause of existence. This theory of certainty has been examined before. The second argument is. That whatever we can conceive is possible. This has like- wise been examined. The third' argument is, That what we call a cause, is only something antecedent to, and always conjoined with, the effect. This is also one of Mr Hume's peculiar doctrines, which we may have occasion to consider afterwards. It is sufficient here to observe, that we may leai n from it that night is the cause of day, and day the cause of night : for no two things have more constantly followed each other since the beginning of the world. The [third and] last metaphysical prin- ciple I mention, which is opposed by the same author, is, That design and intelii- gence in the cause may be inferred, with certainly, from marks or signs of it in the effect. * See above, p. 444, note*. It is the triumph of scepticism to shew that speculation and practice are irreconcilable. — H. 45H ON THE INTELLECTUAL POWERS. Less ay vi. Intelligence, design, and skill, are not objects of the external senses, nor can we be conscious of them in any person but our- selves. Even in ourselves, we cannot, with propriety, be said to be corecious of the natural or acquired talents we possess. We are conscious only of the operations of mind in which they are exerted. Indeed, a man comes to know his own mental abilities, just as he knows another man's, by the effects they produce, when there is occasion to put them to exercise. A man's wisdom is known to us only by the signs of it in his conduct ; his eloquence by the signs of it in his speech. In the same manner, we judge of his virtue, of his forti- tude, and of all his talents and virtues. [622] Yet it is to be observed, that we judge of men's talents with as little doubt or hesita- tion as we judge of the immediate objects of sense. One person, we are sure, is a perfect idiot ; another, who feigns idiocy to screen himself from punishment, is found, upon trial, to have the understanding of a man, and to be accountable for his conduct. We perceive one man to be open, another cun- ning; one to be ignorant, another very knowing ; one to be slow of understanding, another quick. Every man forms such judgments of those he converses with ; and the common affairs of life depend upon such j udgments. We can as little avoid them as we can avoid seeing what is before our eyes. From this it appears, that it is no less a part of the human constitution, to judge of men's characters, and of their intellectual powers, from the signs of them in their actions and discourse, than to judge of cor- poreal objects by our senses ; that such judgments are common to the whole human race that are endowed with understanding ; and that they are absolutely necessary in the conduct of life. Now, every judgment of this kind we form, is only a particular application of the general principle, that intelligence, wisdom, and other mental qualities in the cause, may be inferred from their marks or signs in the effect. The actions and discourses of men are effects, of which the actors and speakers are the causes. The effects are perceived by our senses ; but the causes are behind the scene. We only conclude their exist- ence and their degrees from our observa- tion of the effects. From wise conduct, we infer wisdom in the cause ; from brave actions, we infer courage ; and so in other eases. [623] This inference is made with perfect secu- rity by all men. We cannot avoid it ; it is necessary in the ordinary conduct of life ; it has therefore the strongest marks of being a first principle. Perhaps some may think that this prin- ciple may be learned either by reasoning or by experience, and therefore that there is no ground to think it a first principle. If it can be shewn to be got by reasoning, by all, or the greater part of those who are governed by it, I shall very readily ac- knowledge that it ought not to be esteemed a first principle. But I apprehend the con- trary appears from very convincing argu- ments. First, The principle is too universal to be the effect of reasoning. It is common to philosophers and to the vulgar ; to the learned and to the most illiterate ; to the civilized and to the savage. And of those who are governed by it, not one in ten thousand can give a reason for it. Secondly, We find philosophers, ancient and modern, who can reason excellently in subjects that admit of reasoning, when they have occasion to defend this principle, not offering reasons for it, or any medium of proof, but appealing to the common sense of mankind ; mentioning particular instan- ces, to make the absurdity of the contrary opinion more apparent, and sometimes using the weapons of wit and ridicule, which are very proper weapons for refuting ab- surdities, but altogether improper in points that are to be determined by reasoning. To confirm this observation, I shall quote two authors, an ancient and a modern, who have more expressly undertaken the defence of this principle than any others I remem- ber to have met with, and whose good sense and ability to reason, where reasoning is proper, will not be doubted. [624] The first is Cicero, whose words, {Lb. I. cap. 13. De Divinatione,) may be thus translated. " Can anything done by chance have all the marks of design ? Four dice may by chance turn up four aces ; but do you think that four hundred dice, thrown by chance, will turn up four hundred aces ? Colours thrown upon canvas without design may have some similitude to a human face ; but do you think they might make as beautiful a picture as that of the Coan Venus ? A hog turning up the ground with his nose may make something of the form of the let- ter A ; but do you think that a hog might describe on the ground the Andromache of Ennius ? Carneades imagined that, in the stone quarries at Chios, he found, in a stone that was split, a representation of the head of a little Pan, or sylvan deity. I believe he might find a figure not unlike ; but surely not such a one as you would say had been formed by an excellent sculptor like Scopas. For so, verily, the case is, that chance never perfectly imitates design." Thus Cicero.* * See alio Cicero " De Naiura Dcorum," 1. ii. a 37 — H. [622-624] chap. vi.J FIRST PRINCIPLES OF NECESSARY TRUTHS. 459 Now, in all this discourse, I see very good sense, and what is apt to convince every unprejudiced mind ; but I see not in the whole a single step of reasoning. It is barely an appeal to every man's common r Let us next see how the same point is handled by the excellent Archbishop Tillot- son. (1st Sermon, vol. i.) "For I appeal to any man of reason, whether anything can be more unreasonable than obstinately to impute an effect to chance which carries in the face of it all the argu- ments and characters of design ? Was ever any considerable work, in which there was required a great variety of parts, and an orderly and regular adjustment of these parts, done by chance ? Will chance fit means to ends, and that in ten thousand instances, and not fail in any one ? [625] How oftenmight a man, after he had jumbled a set of letters in a bag, fling them out upon the ground before they would fall into an exact poem, yea, or so much as make a good discourse in prose ? And may not a little book be as easily made as this great volume of the world ? How long might a man sprinkle colours upon canvass with a careless hand, before they would make the exact picture of a man ? And is a man easier made by chance than his picture ? How long might twenty thousand blind men, which should be sent out from the remote parts of England, wander up and down be- fore they would all meet upon Salisbury plains, andfall into rank and file in the exact order of an army ? And yet this is much more easy to be imagined than how the innumerable blind parts of matter should rendezvous themselves into a word. A man that sees Henry VII. 's chapel at West- minster might, with as good reason, main- tain, (yea, and much better, considering the • vast difference between that little structure and the huge fabric of the world,) that it was never contrived or built by any man, but that the stones did by chance grow into those curious figures into which we see them to have been cut and graven ; and that, upon a time, (as tales usually begin,) the mate- rials of that building — the stone, mortar, timber, iron, lead, and glass — happily met together, and very fortunately ranged them- selves into that delicate order in which we see them now, so close compacted that it must be a very great chance that parts them again. What would the world think of a man that should advance such an opinion as this, and write a book for it ? If they would do him right, they ought to look upon him as mad. But yet he might maintain this opinion with a little more reason than any man can have to say that the world was made by chance, or that the first men grew out of the earth, as plants do now ; for, can r 625-627T anything be more ridiculous and against all reason, than to ascribe the production of men to the first fruitfulness of the earth, without so much as one instance or experi- ment in any age or history to countenance so monstrous a supposition * The thing is at first sight so gross and palpable, that no discourse about it can make it more appa- rent. And yet these shameful beggars of principles, who give this precarious account of the original of things, assume to them- selves to be the men of reason, the great wits of the world, the only cautious and wary persons, who hate to be imposed upon, that must have convincing evidence for every- thing, and can admit nothing without a clear demonstration for it." [626] In this passage, the excellent author takes what I conceive to be the proper method of refuting an absurdity, by exposing it in dif- ferent lights, in which every man of common understanding conceives it to be ridiculous. And, although there is much good sense, as well as wit, in the passage I have quoted, I cannot find one medium of proof in the whole. I have met with one or two respectable authors who draw an argument from the doctrine of chances, to shew how impro- bable it is that a regular arrangement of parts should be the effect of chance, or that it should not be the effect of design. I do not object to this reasoning ; but I would observe that the doctrine of chances is a branch of mathematics little more than an hundred years old. But the conclusion drawn from it has been held by all men from the beginning of the world. It cannot, therefore, be thought that men have been led to this conclusion by that reasoning. Indeed, it may be doubted whether the first principle upon which all the mathematical reasoning about chances is grounded, is more self-evident than this conclusion drawn from it, or whether it is not a particular instance of that general conclusion. We are next to consider whether we may not learn this truth from experience, That effects which have all the marks and tokens of design, must proceed from a designing cause. [627] I apprehend that we cannot learn this truth from experience for two reasons. First, Because it is a necessary truth, not a contingent one. It agrees with the experience of mankind since the beginning of the world, that the area of a triangle is equal to half the rectangle under its base and perpendicular. It agrees no less with experience, that the sun rises in the east and sets in the west. So far as experience goes, these truths are upon an equal footing. But every man perceives this distinction between them — that the first is a necessary truth, and that it is impossible it should uot 4fiO ON THE INTELLECTUAL POWERS. Qessay VI be true ; but the last is not necessary, but contingent, depending upon the will of Him who made the world. As we cannot learn from experience that twice three must ne- cessarily make six, so neither can we learn from experience that certain effects must proceed from a designing and intelligent cause. Experience informs us only of what has been, but never of what must be.* Secondly, It may be observed, that ex- perience can shew a connection between a sign and the thing signified by it, in those cases only where both the sign and thing signified are perceived and have always been perceived in conjunction. But, if there be any case where the sign only is per- ceived, experience can never shew its con- nection with the thing signified. Thus, for example, thought is a sign of a thinking principle or mind. But how do we know that thought cannot be without a mind ? If any man should say that he knows this by experience, he deceives himself. It is im- possible he can have any experience of this ; because, though we have an immediate knowledge of the existence of thought in ourselves by consciousness, yet we have no immediate knowledge of a mind. The mind is not an immediate object either of sense or of consciousness. We may, therefore, justly conclude, that the necessary con- nection between thought and a mind, or thinking being, is not learned from expe- rience. [628] The same reasoning may be applied to the connection between a work excellently fitted for some purpose, and design in the author or cause of that work. One of these — to wit, the work — may be an immediate object of perception. But the design and purpose of the author cannot be an imme- diate object of perception; and, therefore, experience can never inform us of any con- nection between the one and the other, far less of a necessary connection. Thus, I think, it appears, that the prin- ciple we have been considering— to wit, that from certain signs or indications in the effect, we may infer that there must have been intelligence, wisdom, or other intel- lectual or moral qualities hi the cause, is a principle which we get, neither by reason- ing nor by experience ; and, therefore, if it be a true principle, it must be a first prin- ciple. There is in the human understand- ing a light, by which we see immediately the evidence of it, when there is occasion to apply it. Of how great importance this principle is in common life, we have already observed. And I need hardly mention its importance in natural theology. The clear marks and signatures of wis- * See above p. 153; and " Active Powers," p. 31.— H. dom, power, and goodness, in the consti- tution and government of the world, is, of all arguments that have been advanced for the being and providence of the Deity, that which in all ages has made the strongest impression upon candid and thinking minds ; an argument, which has this peculiar ad- vantage, that it gathers strength as human knowledge advances, and is more convincing at present than it was some centuries ago. King Alphonsus might say, that he could contrive a better planetary system than that which astronomers held in his day.* That system was not the work of God, but the fiction of men. [629] But since the true system of the sun, moon, and planets, has been discovered, no man, however atheistically disposed, has pretended to shew how a better could be contrived. When we attend to the marks of good contrivance which appear in the works of God, every discovery we make in the con- stitution of the material or intellectual system becomes a hymn of praise to the great Creator and Governor of the world. And a man who is possessed of the genuine spirit of philosophy will think it impiety to contaminate the divine workmanship, by mixing it with those fictions of human fancy, called theories and hypotheses, which will always bear the signatures of human folly, no less than the other does of divine wis- dom. I know of no person who ever called in question the principle now under our consi- deration, when it is applied to the actions and discourses of men. For this would be to deny that we have any means of discerning a wise man from an idiot, or a man that is illiterate in the highest degree from a man of knowledge and learning, which no man has the effrontery to deny. But, in all ages, those who have been unfriendly to the principles of religion, have made attempts to weaken the force of the argument for the existence and perfec- tions of the Deity, which is founded on this principle. That argument has got the name of the argument from final causes ; and as the meaning of this name is well understood, we shall use it. The argument from final causes, when re- duced to a syllogism, has these two premises : — First, That design and intelligence in the cause, may, with certainty, be inferred from marks or signs of it in the effect. This is the principle we have been considering, and * Alphonso X. of Castile. He flourished iD the thirteenth century— a great mathematician and as- tronomer. To him we owe the Alphonsine Tables. His Baying was not so pious and philosophical as lipid states ; but that, " Had he been present with Ood at the creation, he could have supplied some useful hints towards the better ordering of tile universe." —H [6S8. 629] chap, vi.] FIRST PRINCIPLES OF NECESSARY TRUTHS. 461 we may call it the major proposition of the argument. The second, which we call the minor proposition, is, That there are in fact the clearest marks of design and wisdom in the works of nature ; and the conclusion is, That the works of nature are the effects of a wise and intelligent Cause. One must either assent to the conclusion, or deny one or other of the premises. [630] Those among the ancients who denied a God or a Providence, seem to me to have yielded the major proposition, and to have denied the minor ; conceiving that there are not in the constitution of things such marks of wise contrivance as are sufficient to put the conclusion beyond doubt. This, I think, we may learn, from the reasoning of Cotta the academic, in the third book of Cicero, of the Nature of the Gods. The gradual advancement made in the knowledge of nature, hath put this opinion quite out of countenance. When the structure of the human body was much less known than it is now, the famous Galen saw snch evident marks of wise contrivance in it, that, though he had been educated an Epicurean, he renounced that system, and wrote his book of the use of the parts of the human body, on purpose to convince others of what appeared so clear to himself, that it was impossible that such admirable contrivance should be the effect of chance. Those, therefore, of later times, who are dissatisfied with this argument from final causes, have quitted the stronghold of the ancient atheists, which had become un- tenable, and have chosen rather to make a defence against the major proposition. Des Cartes seems to have led the way in this, though he was no atheist. But, having invented some new arguments for the being of God, he was, perhaps, led to disparage those that had been used before, that he might bring more credit to his own. Or perhaps he was offended with the Peripa- tetics, because they often mixed final causes with physical, in order to account for the phenomena of nature. [631 ] He maintained, therefore, that physical causes only should be assigned for phaeno- mena ; that the philosopher has nothing to do with final causes ; and that it is pre- sumption in us to pretend to determine for what end any work of nature is framed. Some of those who were great admirers of Des Cartes, and followed him in many points, differed from him in this, particu- larly Dr Henry More and the pious Arch- bishop Fenelon : but others, after the ex- ample of Des Cartes, have shewn a contempt of all reasoning from final causes. Among these, I think, we may reckon Maupertuis and Button. But the most direct attack has been made upon this principle by Hi [630-632] Hume, who puts an argument in the mouth of an Epicurean, on which he seems to lay great stress. The argument is, That the universe is a singular effect, and, therefore, we can draw no conclusion from it, whether it may have been made by wisdom or not. * If I understand the force of this argu- ment, it amounts to this, That, if we had been accustomed to see worlds produced, some by wisdom and others without it, and had observed that such a world as this which we inhabit was always the effect of wisdom, we might then, from past experi- ence, conclude that this world was made by wisdom; but, having no such experi- ence, we have no means of forming any conclusion about it. That this is the strength of the argument appears, because, if the marks of wisdom seen in one world be no evidence of wisdom, the like marks seen in ten thousand will give as little evidence, unless, in time past, we perceived wisdom itself conjoined with the tokens of it ; and, from their perceived conjunction in time past, conclude that, al- though, in the present world, we see only one of the two, the other must accompany it. [632] Whence it appears that this reasoning of Mr Hume is built on the supposition that our inferring design from the strongest marks of it, is entirely owing to our past experience of having always found these two things conjoined- But I hope I have made it evident that this is not the case. And, indeed, it is evident that, according to this reasoning, we can have no evidence of mind or design in any of our fellow- men. How do I know that any man of my ac- quaintance has understanding ? I never saw his understanding. I see only cer- tain effects, which my judgment leads me to conclude to be marks and tokens of it. But, says the sceptical philosopher, you can conclude nothing from these tokens, un- less past experience has informed you that such tokens are always joined with under- standing. Alas ! sir, it is impossible I can ever have this experience. The understand- ing of another man is no immediate object of sight, or of any other faculty which God hath given me ; and unless I can conclude its existence from tokens that are visible, I have no evidence that there is understand- ing in any man. It seems, then, that the man who main- tains that there is no force in the argument from final causes, must, if he will be con- sistent, see no evidence of the existence of any intelligent being but himself. * See Stewart's " Element-," it. p 579.— H. 462 ON THE INTELLECTUAL POWERS. [essay CHAPTER VII. OPINIONS, ANCIENT AND MODERN, ABOUT FIRST PRINCIPLES. I know no writer who has treated ex- pressly of first principles before Aristotle ; but it is probable that, in the ancient Py- thagorean school, from which both Plato and Aristotle borrowed much, this subject had not been left untouched. [633] Before the time of Aristotle, considerable progress had been made in the mathema- tical sciences, particularly in geometry. The discovery of the forty-seventh pro- position of the first book of Euclid, and of the five regular solids, is, by antiquity, ascribed to Pythagoras himself; and it is impossible he could have made those dis- coveries without knowing many other pro- positions in mathematics. Aristotle.- men- tions the incommensurability of the diagonal of a square to its side, and gives a hint of the manner in which it was demonstrated. We find likewise some of the axioms of geometry mentioned by Aristotle as axioms, and as indemonstrable principles of mathe- matical reasoning. It is probable, therefore, that, before the time of Aristotle, there were elementary treatises of geometry, which are now lost ; and that in them the axioms were distin- guished from the propositions which require ] roof. To suppose that so perfect a system as that of Euclid's " Elements" was produced by one man, without any preceding model or materials, would be to suppose Euclid more than a man. We ascribe to him as much as the weakness of human under- standing will permit, if we suppose that the inventions in geometry, which had been made in a tract of preceding ages, were by him not only carried much farther, but digested into so admirable a system that his work obscured all that went before it, and made them be forgot and lost. Perhaps, in like manner, the writings of Aristotle with regard to first principles, and with regard to many other abstract subjects, may have occasioned the loss of what had been written upon those subjects by more ancient philosophers. [634] Whatever may be in this, in his second book upon demonstration, he has treated very fully of first principles ; and, though he has not attempted any enumeration of them, he shews very clearly that all demonstra- tion muBt be built upon truths which are evident of themselves, but cannot be de- monstrated. His whole doctrine of syllo- gisms is grounded upon a few axioms, from which he endeavours to demonstrate the rules of syllogism in a mathematical way ; and in his topics he points out many of the first principles of probable reasoning. As long as the philosophy of Aristotle prevailed, it was held as a fixed point, that all proof must be drawn from principles already known and granted. We must observe, however, that, in that philosophy, many things were assumed as first principles, which have no just claim to that character : such as, that the earth is at rest ; that nature abhors a vacuum ; that there is no change in the heavens above the sphere of the moon ; that the heavenly bodies move in circles, that being the most perfect figure ; that bodies do not gravitate in their proper place ; and many others. The Peripatetic philosophy, therefore, instead of being deficient in first principles, was redundant ; instead of rejecting those that are truly such, it adopted, as first principles, many vulgar prejudices and rash judgments : and this seems in general to have been the spirit of ancient philosophy.* It is true, there were among the ancients sceptical philosophers, who professed to have no principles, and held it to be the greatest virtue in a philosopher to withhold assent, and keep his judgment in a perfect equil - brium between contradictory opinions. But, though this sect was defended by some per- sons of great erudition and acuteness, it died of itself, and the dogmatic philosophy of Aristotle obtained a complete triumph over it. [635] What Mr Hume says of those who are sceptical with regard to moral distinctions seems to have had its accomplishment in the ancient sect of Sceptics. " The only way," says he, " of converting antagonists of this kind is to leave them to themselves ; for, finding that nobody keeps up the con- troversy with them, it is probable they will at last of themselves, from mere weariness, come over to the side of common sense and reason." Setting aside this small sect of the Scep- tics, which was extinct many ages before the authority of Aristotle declined, I know of no opposition made to first principles among the ancients. The disposition was, as has been observed, not to oppose, but to mul- tiply them beyond measure. Men have always been prone, when they leave one extreme, to run into the opposite ; and this spirit, in the ancient philosophy, to multiply first principles beyond reason, was a strong presage that, when the authority of the Peripatetic system was at an, end, * The Peripatetic philosophy did not assume any such principles as original and self-evident ; but pro. fessed to establish them all upon induction and gene, ralization. In practice its induction of 'instances might be imperfect, and its generalization from par. titulars rash j but in theory, at least, it was correct. — a. [633-6351 chap, vii.] OPINIONS ABOUT FIRST PRINCIPLES. 463 the next reigning system would diminish their number beyond reason. This, accordingly, happened in that great revolution of the philosophical republic brought about by Des Cartes. That truly great reformer in philosophy, cautious to avoid the snare in which Aristotle was taken, of admitting things as first principles too rashly, resolved to doubt of everything, and to withhold his assent, until it was forced by the clearest evidence.* Thus Des Cartes brought himself into that very state of suspense which the an- cient Sceptics recommended as the highest perfection of a wise man, and the only road to tranquillity of mind. But he did not remain long in this state ; his doubt did not arise from despair of finding the truth, but from, caution, that he might not be im- posed upon, and embrace a cloud instead of a goddess. [636] His very doubting convinced him of his own existence ; for that which does not exist can neither doubt, nor believe, nor reason. Thus he emerged from universal scepti- cism by this short enthymeme, Cogito, ergo sum. This enthymeme consists of an antece- dent proposition, / think, and a conclusion drawn from it, therefore I exist. If it should be asked how Des Cartes came to be certain of the antecedent proposi- tion, it is evident that for this he trusted to the testimony of consciousness. He was con- scious that he thought, and needed no other argument. So that the first principle which he adopts in this famous enthymeme is this, That those doubts, and thoughts, and reasonings, of which he was conscious, did certainly exist, and that his consciousness put their exist- ence beyond all doubt. It might have been objected to this first principle of Des Cartes, How do you know that your consciousness cannot deceive you ? You have supposed that all you see, and hear, and handle, may be an illusion. Why, therefore, should the power of conscious- ness have this prerogative, to be believed implicitly, when all our other powers are supposed fallacious ? To this objection I know no other answer that can be made but that we find it im- possible to doubt of things of which we are conscious. The constitution of our nature forces this belief upon us irresistibly. This is true, and is sufficient to justify Des Cartes in assuming, as a first principle, the existence of thought, of which he was conscious. [637] He ought, however, to have gone farther in this track, and to have considered whe- ther there may not be other first principles * On the Cartesian doubt, see Note R.— H. [636-638] which ought to be adopted for the same reason. But he did not see this to be ne- cessary, conceiving that, upon this ons first principle, he could support the whole fabric of human knowledge. To proceed to the conclusion of Des Cartes's enthymeme. From the existence of his thought he infers his own existence. Here he assumes another first principle, not a contingent, but a necessary one ; to wit, that, where there is thought, there must be a thinking being or mind. Having thus established his own exist- ence, he proceeds to prove the existence of a supreme and infinitely perfect Being ; and, from the perfection of the Deity, he infers that his senses, his memory, and the other faculties which God had given hiiu, are not fallacious. Whereas other men, from the beginning of the world, had taken for granted, as a l.rst principle, the truth and reality of what they perceive by their senses, and from thence inferred the existence of a Supreme Author and Maker of the world, Des Cartes took a contrary course, conceiving that the tes- timony of our senses, and of all our facul- ties, excepting that of consciousness, ought not to be taken for granted, but to be proved by argument. Perhaps some may think that Des Car- tes meant only to admit no other first prin- ciple of contingent truths besides that of consciousness ; but that he allowed the axi- oms of mathematics, and of other necessary truths, to be received without proof. [638] But I apprehend this was not his inten- tion ; for the truth of mathematical axioms must depend upon the truth of the faculty by which we judge of them. If the faculty be fallacious, we may be deceived by trust- ing to it. Therefore, as he supposes that all our faculties, excepting consciousness, may be fallacious, and attempts to prove by argument that they are not, it follows that, according to his principles, even ma- thematical axioms require proof. Neither did he allow that there are any necessary truths, but maintained, that the truths which are commonly so called, depend up- on the will of God. And we find his fol- lowers, who may be supposed to under- stand his principles, agree in maintaining, that the knowledge of our own existence is the first and fundamental principle from which all knowledge must be deduced by one who proceeds regularly in philosophy. There is, no doubt, a beauty in raising a large fabric of knowledge upon a few firtt principles. The stately fabric of mathema- tical knowledge, raised upon the foundation of a few axioms and definitions, charms every beholder. Des Cartes, who was well acquainted with this beauty in the mathe- matical sciences, seems to have been am. 464 ON THE INTELLECTUAL POWERS. [essay VI, bitious to give the same beautiful simplicity to his system of philosophy ; and therefore sought only one first principle as the founda- tion of all our knowledge, at least of con- tingent truths. And so far has his authority prevailed, that those who came after him have almost universally followed him in this track. This, therefore, may be considered as the spirit of modern philosophy, to allow of no first principles of contingent truths but this one, that the thoughts and opera- tions of our own minds, of which we are conscious, are self-evidently real and true ; but that everything else that is contingent is to he proved by argument. The existence of a material world, and of what we perceive by our senses, is not self-evident, according to this philosophy. Des Cartes founded it upon this argument, that God, who hath given us our senses, and all our faculties, is no deceiver, and therefore they are not fallacious. [639] I endeavoured to shew that, if it be not admitted as a first principle, that our facul- ties are not fallacious, nothing else can be admitted ; and that it is impossible to prove this by argument, unless God should give us new faculties to sit in judgmentupon the old. Father Malebranche agreed with Des Cartes, that the existence of a material world requires proof ; but, being dissatisfied with Des Cartes's argument from the per- fection of the Deity, thought that the only solid proof is from divine revelation. Arnauld, who was engaged in controversy with Malebranche, approves of his anta- gonist in offering an argument to prove the existence of the material world, but objects to the solidity of his argument, and offers other arguments of his own. Mr Norris, a great admirer of Des Cartes and of Malebranche, seems to have thought all the arguments offered by them and by Arnauld to be weak, and confesses that we have, at best, only probable evidence of the existence of the material world. Mr Locke acknowledges that the evidence we have of this point is neither intuitive nor demonstrative ; yet he thinks it may be called knowledge, and distinguishes it by the name of sensitive knowledge ; and, as the ground of this sensitive knowledge, he offers some weak arguments, which would rather tempt one to doubt than to believe. At last, Bishop Berkeley and Arthur Collier, without any knowledge of each other, as far as appears by their writings, undertook to prove, that there neither is nor can be a material world. The excel- lent style and elegant composition of the former have made his writings to be known and read, and this system to be attributed to him only, as if Collier had never ex- isted. [640] Both, indeed, owe so much to Male- branche, that, if we take out of his system the peculiarities of our seeing all things iu God, and our learning the existence of an external world from divine revelation, what remains is just the system of Bishop Berke- ley. I make this observation, by the way, in justice to a foreign author, to whom British authors seem not to have allowed all that is due. * Mr Hume hath adopted Bishop Berke- ley's arguments against the existence of matter, and thinks them unanswerable. We may observe, that this great meta- physician, though in general he declares in favour of universal scepticism, and there- fore may seem to have no first principles at all, yet, with Des Cartes, he always acknow- ledges the reality of those thoughts and operations of mind of which we are con- scious, -f- So that he yields the antecedent of Des Cartes's enthymeme cogito, but denies the conclusion ergo sum, the mind being, according to him, nothing but that train of impressions and ideas of which we are conscious. Thus, we see that the modern philosophy, of which Des Cartes may justly be ac- counted the founder, being built upon the ruins of the Peripatetic, has a spirit quite opposite, and runs into a contrary extreme. The Peripatetic not only adopted as first principles those which mankind have always rested upon in their most important trans- actions, but, along with them, many vulgar prejudices ; so that this system was founded upon a wide bottom, but in many parts unsound. The modern system has nar- rowed the foundation so much, that every superstructure raised upon it appears top- heavy. From the single principle of the exist- ence of our own thoughts, very little, if any thing, can be deduced by just reasoning, especially if we suppose that all our other faculties may be fallacious. Accordingly, we find that Mr Hume was not the first that was led into scepticism by the want of first principles. For, soon after Des Cartes, there arose a sect in France called Egoists, who maintained that we have no evidence of the existence of any- thing but ourselves. J [641] Whether these egoists, like Mr Hume, * If I rocollect aright, (I write this note at a dis- tance from books,) Locke explicitly anticipates the Berkeleian idealism in his '< Examination ol Father Malebranche's Opinion." This was also done oy Bayle. In fact, Malebranche, and many others be. fore him, would inevitably have become Idealists, had they not been Catholics. But an Idealist, as I have already observed, no consistent Catholic cnvild — rt S. 12— H. [670-672] and the proposition or propositions from which it is inferred, the premises. [672] Reasoning may consist of many steps ; the first conclusion being a premise to a second, that to a third, and so on, till we come to the last conclusion. A process consisting of many steps of this kind, is so easily distinguished from judgment, that it is never called by that name. But when there is only a single step to the conclusion, the distinction is less obvious, and the pro- cess is sometimes called judgment, some- times reasoning. It is not strange that, in common dis- course, judgment and reasoning should not be very nicely distinguished, since they are in some cases confounded even by logicians. We are taught in logic, that judgment is expressed by one proposition, but that rea- soning requires two or three. But so various are the modes of speech, that what in one mode is expressed by two or three propositions, may, in another mode, be ex- pressed by one. Thus I may say, God is pood ; therefore good men shall be happy. Phis is reasoning, of that kind which logi- cians call an enthymeme, consisting of an antecedent proposition, and a conclusion drawn from it.* But this reasoning may * The enthymeme is a mere abbreviation of expres- sion ; in the mental process there is no ellipsis. By 476 ON THE INTELLECTUAL POWERS. [essay vil, be expressed by one proposition, thus: — Because God is good, good men shall be happy. This is what they call a causal proposition, and therefore expresses judg- ment ; yet the enthyraeme, which is reason- ing, expresses no more. Reasoning, as well as judgment, must he true or false : both are grounded upon evi- dence which may be probable or demonstra- tive, and both are accompanied with assent or belief. [673] The power of reasoning is justly accounted one of the prerogatives of human nature ; because by it many important truths have been and may be discovered, which with- out it would be beyond our reach ; yet it seems to be only a kind of crutch to a limited understanding. "We can conceive an understanding, superior to human, to which that truth appears intuitively, which we can only discover by reasoning. For this cause, though we must ascribe judg- ment to the Almighty, we do not ascribe reasoning to him, because it implies some defect or limitation of understanding. Even among men, to use reasoning in things that are self-evident, is trifling ; like a man going upon crutches when he can walk upon his legs. What reasoning is, can be understood only by a man who has reasoned, and who is capable of reflecting upon this operation of his own mind. We can define it only by synonymous words or phrases, such as in- ferring, drawing a conclusion, and the like. The very notion of reasoning, therefore, can enter into the mind by no other channel than that of reflecting upon the operation of reasoning in our own minds ; and the notions of premises and conclusion, of a syllogism and all its constituent parts, of an enthymeme, sorites, demonstration, pa- ralogism, and many others, have the same origin. It is nature, undoubtedly, that gives us the capacity of reasoning. When this is wanting, no art nor education can supply it. But this capacity may be dormant through life, like the seed of a plant, which, for want of heat and moisture, never vegetates. This is probably the case of some savages. Although the capacity be purely the gift of nature, and probably given in very dif- ferent degrees to different persons ; yet the power of reasoning seems to be got by habit, as much as the power of walking or running. Its first exertions we are not able to recol- lect in ourselves, or clearly to discern in others. They are very feeble, and need to be led by example, and supported by autho- rity. By degrees it acquires strength, chiefly by means of imitation and exer- c ise. [674] mthiimeme, Aristotle also meant something very dif- ferent trom what is vulgarly supposed.— H. The exercise of reasoning on various sub. jects not only strengthens the faculty, but furnishes the mind with a store of materials. Every train of reasoning, which is familiar, becomes a beaten track in the way to many others. It removes many obstacles which lay in our way, and smooths many roads which we may have occasion to travel in future disquisitions. When men of equal natural parts apply their reasoning power to any subject, the man who has reasoned much on the same or on similar subjects, has a like advantage over him who has not, as the mechanic who has store of tools for his work, has of him who has his tools to make, or even to invent. In a train of reasoning, the evidence of every step, where nothing is left to be sup- plied by the reader or hearer, must be im- mediately discernible to every man of ripe understanding who has a distinct compre- hension of the premises and conclusion, and who compares them together. To be able to comprehend, in one view, a combination of steps of this kind, is more difficult, and seems to require a superior natural ability. In all, it may be much improved by habit. But the highest talent in reasoning is the invention of proofs ; by which, truths re- mote from the premises are brought to light. In all works of understanding, invention has the highest praise 1 it requires an ex- tensive view of what relates to the subject, and a quickness in discerning those affinities and relations which may be subservient tc the purpose. In all invention there must be some end in view : and sagacity in finding out the road that leads to this end, is, I think, what we call invention. In this chiefly, as I ap- prehend, and in clear and distinct concep- tions, consipts that superiority of under- standing which we call genivs. [675] In every chain of reasoning, the evidence of the last conclusion «an be no greater than that of the weakest link of the cham, what- ever may be the strength of the rest. The most remarkable distinction of rea- sonings is, that some are probable, others demonstrative. In every step of demonstrative reason- ing, the inference is necessary, and we per- ceive it to be impossible that the conclusion should not follow from the premises. In probable reasoning, the connection between the premises and the conclusion is not neces- sary, nor do we perceive it to be impossible that the first should be true while the last is false. Henee, demonstrative reasoning has no degrees, nor can one demonstration be stronger than another, though, in relation to our faculties, one may be more easilv comprehended than another. Every do. [673-675] chap, i.] OF REASONING, AND OF DEMONSTRATION. 477 monstration gives equal strength to the con- clusion, and leaves no possibility of its being false. It was, I think, the opinion of all the ancients, that demonstrative reasoning can be applied only to truths that are necessary, and not to those that are contingent. In this, I believe, they judged right. Of all created things, the existence, the attributes, and, consequently, the relations resulting from those attributes, are contingent. They depend upon the will and power of Him who made them. These are matters of fact, and admit not of demonstration. The field of demonstrative reasoning, therefore, is the various relations of things abstract, that is, of things which we con- ceive, without regard to their existence. Of these, as they are conceived by the mind, and are nothing but what they are conceived to be, we may have a clear and adequate comprehension. Their relations and attri- butes are necessary and immutable. They are the things to which the Pythagoreans and Platonists gave the name of ideas. I would beg leave to borrow this meaning of the word idea from those ancient philoso- phers, and then I must agree with them, that ideas are the only objects about which we can reason demonstratively. [676] There are many even of our ideas about which we can carry on no considerable train of reasoning. Though they be ever so well defined and perfectly comprehended, yet their agreements and disagreements are few, and these are discerned at once. We may go a step or two in forming a conclusion with regard to such objects, but can go no farther. There are others, about which we may, by a long train of demonstrative rea- soning, arrive at conclusions very remote and unexpected. The reasonings I have met with that can be called strictly demonstrative, may, I think, be reduced to two classes. They are either metaphysical, or they are mathe- matical. In metaphysical reasoning, the process is always short. The conclusion is but a step or two, seldom more, from the first principle or axiom on which it is grounded, and the different conclusions depend not one upon another. It is otherwise in mathematical reason- ing. Here the field has no limits. One proposition leads on to another, that to a third, and so on without end. If it should be asked, why demonstrative reasoning has so wide a field in mathema- tics, while, in other abstract subjects, it is confined within very narrow limits, I con- ceive this is chiefly owing to the nature of quantity, the object of mathematics. Every quantity, as it has magnitude, and is divisible into parts without end, so, in [676-678] respect of its magnitude, it has a certain ratio to every quantity of the kind. The ratios of quantities are innumerable, such as, a half, a third, a tenth, double, triple. [677] All the powers of number are in- sufficient to express the variety of ratios. For there are innumerable ratios which cannot be perfectly expressed by numbers, such as, the ratio of the side to the diagonal of a square, or of the circumference of a circle to the diameter. Of this infinite variety of ratios, every one may be clearly conceived and distinctly expressed, so as to be in no danger of being mistaken for any other. Extended quantities, such as lines, sur- faces, solids, besides the variety of relations they have in respect of magnitude, have no less variety in respect of figure ; and every mathematical figure may be accurately defined, so as to distinguish it from all others. There is nothing of this kind in other objects of abstract reasoning. Some of them have various degrees ; but these are not capable of measure, nor can be said to have an assignable ratio to others of the kind. They are either simple, or com- pounded of a few indivisible parts; and therefore, if we may be allowed the expres- sion, can touch only in few points. But mathematical quantities being made up of parts without number, can touch in innu- merable points, and be compared in innu- merable different ways. There have been attempts made to mea- sure the merit of actions by the ratios of the affections and principles of action from which they proceed. This may perhaps, in the way of analogy, serve to illustrate what was before known ; but I do not think any truth can be discovered in this way. There are, no doubt, degrees of benevolence, self-love, and other affections ; but, when we apply ratios to them, I apprehend we have no distinct meaning. Some demonstrations are called direct, others indirect. The first kind leads directly to the conclusion to be proved. Of the indirect, some are called demonstrations ad absurdum. In these, the proposition con- tradictory to that which is to be proved is demonstrated to be false, or to lead to an absurdity ; whence it follows, that its con- tradictory — that is, the proposition to be proved — is true. This inference is grounded upon an axiom in logic, that of two contra- dictory propositions, if one be false, the other must be true.* [678] Another kind of indirect demonstration proceeds by enumerating all the supposi- tions that can possibly be made concerning the proposition to be proved, and then * This is called the principle of Excluded Middie-* Tiz., between two contradictories — H 47B ON THE INTELLECTUAL POWERS. {essa ir vii. demonstrating that all of them, excepting that which is to- be proved, are false ; whence it follows, that the excepted supposition is true. Thus, one line is proved to be equal to another, by proving first that it cannot be greater, and then that it cannot be less : for it must be either greater, or less, or equal ; and two of these suppositions being demon- strated to be false, the third must be true. All these kinds of demonstration are used in mathematics, and perhaps some others. They have all equal strength. The direct demonstration is preferred where it can be had, for this reason only, as I apprehend, because it is the shortest road to the con- clusion. The nature of the evidence, and its strength, is the same in all : only we are conducted to it by different roads. CHAPTER II. WHETHER MORALITY BE CAPABLE OF DEMONSTRATION. What has been said of demonstrative reasoning, may help us to judge of an opi- nion of Mr Locke, advanced in several places of his Essay — to wit, " That morality is capable of demonstration as well as mathe- matics." In book III., chap. 11, having observed that mixed modes, especially thdse belong- ing to morality, being such combinations of ideas as the mind puts together of its own choice, the signification of their names may be perfectly and exactly defined, he adds— [679] Sect. 16. " Upon this ground it is that I am bold to think that morality is capable of demonstration as well as mathematics ; since the precise real essence of the things moral words stand for may be perfectly known, and so the congruity or incongruity of the things themselves be certainly discovered, in which consists perfect knowledge. Nor let any one object, That the names of sub- stances are often to be made use of in mo- rality, as well as those of modes, from which will arise obscurity ; for, as to sub- stances, when concerned in moral dis- courses, their divers natures are not so much inquired into as supposed : v. g. When we say that man is subject to law, we mean nothing by man but a corporeal rational creature : what the real essence or other qualities of that creature are, in this case, is no way considered." Again, in book IV., ch. iii., § 18 :— " The idea of a Supreme Being, whose workman- ship we are, and the idea of ourselves, being such as are clear in us, would, I suppose, if duly considered and pursued, afford such foundation of our duty and rules of action as might place morality among the sciences capable of demonstration. The relation of other modes may certainly be perceived, as well as those of number and extension ; and I cannot see why they should not be cap- able of demonstration, if due methods were thought on to examine or pursue their agreement or disagreement." He afterwards gives, as instances, two propositions, as moral propositions of which we may be as certain as of any in mathe- matics ; and considers at large what may have given the advantage to the ideas of quantity, and made them be thought more capable of certainty and demonstration. [680] Again, in the 12th chapter of the same book, § 7, 8 : — " This, I think, I may say, that, if other ideas that are the real as well as nominal essences of their several species were pursued in the way familiar to mathe- maticians, they would carry our thoughts farther, and with greater evidence and clearness, than possibly we are apt to ima- gine. This gave me the confidence to advance that conjecture which I suggest, chap iii. — viz., That' morality is capable of demonstration as well as mathematics." From these passages, it appears that this opinion was not a transient thought, but what he had revolved in his mind on dif- ferent occasions. He offers his reasons for it, illustrates it by examples, and considers at length the causes that have led men to think mathematics more capable of demon- stration than the principles of morals. Some of his learned correspondeiits, par- ticularly his friend Mr Molyneux, urged and importuned him to compose a system of morals according to the idea he had ad- vanced in his Essay ; and, in his answer to these solicitations, he only pleads other oc- cupations, without suggesting any change of his opinion, or any great difficulty in the execution of what was desired. The reason he gives for this opinion is ingenious ; and his regard for virtue, the highest prerogative of the human species, made him fond of an opinion which seemed to be favourable to virtue, and to have a just foundation in reason. We need not, however, be afraid that the interest of virtue may suffer by a free and candid examination of this question, or in- deed of any question whatever. For the interests of truth and of virtue can never be found in opposition. Darkness and error may befriend vice, but can never be favour- able to virtue. [681] Those philosophers who think that our determinations in morals are not real judg- ments — that right and wrong in human con» duct are only certain feelings or sensations in the person who contemplates th action — must reject Mr Locke's opinion without examination. For, if the principles of mo- rals be not a matter of judgment, but of [679-68L1 ghap. ii.] WHETHER MORALITY BE DEMONSTRABLE. 479 feeling only, there can be no demonstration of them ; nor can any other reason be given for them, but that men are so constituted by the Author of their being as to contem- plate with pleasure the actions we call vir- tuous, and with disgust those we call vicious. It is not, therefore, to be expected that the philosophers of this class should think this opinion of Mr Locke worthy of ex- amination, since it is founded upon what they think a false hypothesis. But if our determinations in morality be real judg- ments, and, like all other judgments, be either true or false, it is not unimportant to understand upon what kind of evidence those judgments rest. The argument offered by Mr Locke, to shew that morality is capable of demon- stration, is, " That the precise real essence of the things moral words stand for, may be perfectly known, and so the congruity or incongruity of the things themselves be perfectly discovered, in which consists per- fect knowledge." It is true, that the field of demonstration is the various relations of things conceived abstractly, of which we may have perfect and adequate conceptions. And Mr Locke, taking all the things which moral words stand for to be of this kind, concluded that morality is as capable of demonstration as mathematics. I acknowledge that the names of the virtues and vices, of right and obligation, of liberty and property, stand for things abstract, which may be accurately defined, or, at least, conceived as distinctly and adequately as mathematical quantities. And thence, indeed, it follows, that their mutual relations may be perceived as clearly and certainly as mathematical truths. [682] Of this Mr Locke gives two pertinent examples. The first — " Where there is no property, there is no injustice, is," says he, " a proposition as certain as any demon- stration in Euclid." When injustice is defined to be a viola- tion of property, it is as necessary a truth, that there can be no injustice where there is no property, as that you cannot take from a man that which he has not. The second example is, " That no government allows absolute liberty." This is a truth no less certain and necessary. Such abstract truths I would call meta- physical rather than moral. We give the name of mathematical to truths that ex- press the relations of quantities considered abstractly; all other abstract truths may be called metaphysical. But if those men- tioned by Mr Locke are to be called moral truths, I agree with him that there are many such that are necessarily true, and that have all the evidence that mathemati- cal truths can have. T682, 6831 ' It ought, however, to be remembered, that, as was before observed, the relations of things abstract, perceivable by as, ex- cepting those of mathematical quantities, are few, and, for the most part, immediately discerned, so as not to require that train of reasoning which we call demonstration. Their evidence resembles more that of mathematical axioms than mathematical propositions. This appears in the two propositions given as examples by Mr Locke. The first follows immediately from the definition of injustice ; the second from the definition of government. Their evidence may more properly be called intuitive than demon- strative. And this I apprehend to be the case, or nearly the case, of all abstract truths that are not mathematical, for the reason given in the last chapter. [683] The propositions which I think are pro- perly called moral, are those that affirm some moral obligation to be, or not to be incumbent on one or more individual per- sons. To such propositions, Mr Locke's reasoning does not apply, because the sub- jects of the proposition are not things whose real essence may be perfectly known. They are the creatures of God ; their obligation results from the constitution which God hath given them, and the circumstances in which he hath placed them. That an individual hath such a constitution, and is placed in such circumstances, is not an abstract and necessary, but a contingent truth. It is a matter of fact, and, there- fore, not capable of demonstrative evidence, which belongs only to necessary truths. The evidence which every man hath of his own existence, though it be irresistible, is not demonstrative. And the same thing may be said of the evidence which every man hath, that he is a moral agent, and under certain moral obligations. In like manner, the evidence we have of the exist- ence of other men, is not demonstrative ; nor is the evidence we have of their being endowed with those faculties which make them moral and accountable agents. If man had not the faculty given him by God of perceiving certain things in conduct to be right, and others to be wrong, and of perceiving his obligation to do what is right, and not to do what is wrong, he would not be a moral and accountable being. If man be endowed with such a faculty, there must be some things which, by this faculty, are immediately discerned to be right, and others to be wrong ; and, there- fore, there must be in morals, as in other sciences, first principles which do not de. rive their evidence from any antecedent principles, but may be said to be intuitively discerned. Moral truths, therefore, may be divided 480 ON THE INTELLECTUAL POWERS. [essay vii. into two classes — to wit, such as are self- evident to every man whose understanding and moral faculty are ripe, and such as are deduced by reasoning from those that are self-evident. If the first be not discerned without reasoning, the last never can be so by any reasoning. [684] If any man could say, with sincerity, that he is conscious of no obligation to consult his own present and future happiness ; to be faithful to his engagements ; to obey his Maker ; to injure no man ; I know not what reasoning, either probable or demon- strative, I could use to convince him of any moral duty. As you cannot reason in mathematics with a man who denies the axioms, as little can you reason with a man in morals who denies the first principles of morals. The man who does not, by the light of his own mind, perceive some things in conduct to be right, and others to be wrong, is as incapable of reasoning about morals as a blind man is about colours. Such a man, if any such man ever was, would be no moral agent, nor capable of any moral obligation. Some first principles of morals must be immediately discerned, otherwise we have no foundation on which others can rest, or from which we can reason. Every man knows certainly, that, what he approves in other men, he ought to do in like circumstances, and that he ought not to do what he condemns in other men. Every man knows that he ought, with candour, to use the best means of knowing his duty. To every man who has a conscience, these things are self-evident. They are imme- diate dictates of our moral faculty, which is a part of the human constitution ; and every man condemns himself, whether he will or not, when he knowingly acts contrary to them. The evidence of these fundamental principles of morals, and of others that might be named, appears, therefore, to me to be intuitive rather than demonstrative. The man who acts according to the dic- tates of his conscience, and takes due pains to be rightly informed of his duty, is a per- fect man with regard to morals, and merits no blame, whatever may be the imperfec- tions or errors of his understanding;. He who knowingly acts contrary to them, is conscious of guilt, and self-condemned. Every particular action that falls evidently within the fundamental rules of morals, is evidently his duty; and it requires no rea- soning to convince him that it is so. [685] Thus, I think it appears, that every man of common understanding knows certainly, and without reasoning, the ultimate ends he ought to pursue, and that reasoning is necessary only to discover the most proper means of attaining them ; and in this, in- deed, a good man may often be in doubt. Thus, a magistrate knows that it is his duty to promote the good of the community which hath intrusted him with authority ; and to offer to prove this to him by reason/" 1 ing, would be to affront him. But whether such a scheme of conduct in his office, or another, may best serve that end, he may in many cases be doubtful. I believe, in such cases, he can very rarely have demon- strative evidence. His conscience deter- mines the end he ought to pursue, and he has intuitive evidence that his end is good ; but prudence must determine the means of attaining that end ; and prudence can very rarely use demonstrative reasoning, but must rest in what appears most -oba- ble. I apprehend, that, in every kind of duty we owe to God or man, the case is similar — that is, that the obligation of the most general rules of duty is self-evident ; that the application of those rules to particular actions is often no less evident ; and that, when it is not evident, but requires reason- ing, that reasoning can very rarely be of the demonstrative, but must be of the pro- bable kind. Sometimes it depends upon the temper, and talents, and circumstances of the man himself; sometimes upon the character and circumstances of others ; sometimes upon both ; and these are things which admit not of demonstration. [686] Every man is bound to employ the talents which God hath given him to the best pur- pose ; but if, through accidents which he could not foresee, or ignorance which was invincible, they be less usefully employed than they might have been, this will not be imputed to him by his righteous Judge- It is a common and a just observation, that the man of virtue plays a surer game in order to obtain his end than the man of the world. It is not, however, because he reasons better concerning the means of attaining his end ; for the children of this world are often wiser in their generation than the children of light. But the reason of the observation is, that involuntary errors, unforeseen accidents, and invincible ignorance, which affect deeply all the con- cerns of the present world, have no effect upon virtue or its reward. In the common occurrences of life, a man of integrity, who hath exercised his moral faculty in judging what is right and what is wrong, sees his duty without reasoning, as he sees the highway. The cases that require reasoning are few, compared with those that require none ; and a man may be very honest and virtuous who cannot reason, and who knows not what demon- stration means. The power of reasoning, in those that have it, may be abused in morals, as in other matters. To a man who uses it with [681-686] CHAP. III.] OF PROBABLE R.EASONINC. 481 an upright heart, and a single eye to find what is his duty, it will be of great use ; but when it is used to justify what a man has a strong inclination to do, it will only serve to deceive himself and others. When a man can reason, his passions will reason, and they are the most cunning sophists we meet with. .,_ ,Jf the rules of virtue were left to be dis- covered by demonstrative reasoning, or by reasoning of any kind, sad would be the condition of the far greater part of men, who have not the means of cultivating the power of reasoning. As virtue is the busi- ness of all men, the first principles of it are written in their hearts, in characters so legible that no man can pretend ignorance of them, or of his obligation to practise them. [687] Some knowledge of duty and of moral obligation is necessary to all men. With- out it they could not be moral and account- able creatures, nor capable of being mem- bers of civil society. It may, therefore, be presumed that Nature has put this knowledge within the reach of all men. Reasoning and demonstration are weapons which the greatest part of mankind never was able to wield. The knowledge that is necessary to all, must be attainable by all. We see it is so in what pertains to the natural life of man. Some knowledge of things that are useful and things that are hurtful, is so necessary to all men, that without it the species would soon perish. But it is not by reasoning that this knowledge is got, far less by de- monstrative reasoning. It is by our senses, by memory, by experience, by information ; means of knowledge that are open to all men, and put the learned and the unlearned, those who cau reason and those who can- not, upon a level. It may, therefore, be expected, from the analogy of nature, that such a knowledge of morals as is necessary to all men should be had by means more suited to the abili- ties of all men than demonstrative reason- ing is. This, I apprehend, is in fact the case. When men's faculties are ripe, the first principles of morals, into which all moral reasoning may be resolved, are perceived intuitively, and in a manner more analogous to the perceptions of sense than to the con- clusions of demonstrative reasoning. [688] Upon the whole, I agree with Mr Locke, that propositions expressing the congruities and incongruities of things abstract, which moral words stand for, may have all the evidence of mathematical truths. But this is not peculiar to things which moral words stand for. It is common to abstract pro- positions of every kind. For instance, you cannot take from a man what he has not. [6S7-6S9] A man cannot be bound and perfectly free at the same time. I think no man will call these moral truths ; but they are neces- sary truths, and as evident as any in mathe- matics. Indeed, they are very nearly allied to the two which Mr Locke gives as in- stances of moral propositions capable of demonstration. Of such abstract proposi- tions, I think it may more properly be said that they have the evidence of mathemati- cal axioms, than that they are capable of demonstration. There are propositions of another kind, which alone deserve the name of moral pro- positions. They are such as affirm some- thing to be the duty of persons that really exist. These are not abstract propositions ; and, therefore, Mr Locke's reasoning does not apply to them. The truth of all such propositions depends upon the constitution and circumstances of the persons to whom they are applied. Of such propositions, there are some that are self-evident to every man that has a conscience j and these are the principles from which all moral reasoning must be drawn. They may be called the axioms of morals. But our reasoning from these axioms to any duty that is not self-evident can very rarely be demonstrative. Nor is this any detriment to the cause of virtue, because to act against what appears most probable in a matter of duty, is as real a trespass against the first principles of morality, as to act against demonstration ; and, because he who has but one talent in reasoning, and makes the proper use of it, shall be ac- cepted, as well as he to whom God has given ten. [689] CHAPTER III. OF PROBABLE REASONING. The field of demonstration, as has been observed, is necessary truth : the field of probable reasoning is contingent truth — jiot what necessarily must be at all times, but what is, or was y or shall be. No contingent truth is capable of strict demonstration; but necessary truths may sometimes have probable evidence. Dr Wallis discovered many important mathematical truths, by that kind of induc- tion which draws a general conclusion from particular premises. This is not strict de- monstration, but, in some cases, gives as full conviction as demonstration itself ; and a man may be certain, that- a truth is de- monstrable before it ever has been demon- strated. In other cases, a mathematical proposition may have such probable evi- dence from induction or analogy as en- courages the mathematician to investigata Si 482 ON THE INTELLECTUAL POWERS. [essay VII. its demonstration. But still the reasoning, proper to mathematical and other necessary truths, is demonstration ; and that which is proper to contingent truths, is probable reasoning. These two kinds of reasoning differ in other respects. In demonstrative reason- ing, one argument is as good as a thousand- One demonstration may be more elegant than another ; it may be more easily com- prehended, or it may be more subservient to some purpose beyond the present. On any of these accounts it may deserve a preference : but then it is sufficient by it- self ; it needs no aid from another ; it can receive none. To add more demonstrations of the same conclusion, would be a kind of tautology in reasoning ; because one de- monstration, clearly comprehended, gives all the evidence we are capable of receiv- ing. [690] The strength of probable reasoning, for the most part, depends not upon any one argument, but upon many, which unite their force, and lead to the same conclusion. Any one of them by itself would be insuf- ficient to convince ; but the whole taken together may have a force that is irresistible, so that to desire more evidence would be absurd. Would any man seek new argu- ments to prove that there were such persons as King Charles I. or Oliver Cromwell ? Such evidence may be compared to a rope made up of many slender filaments twisted together. The rope has strength more than sufficient to bear the stress laid upon it, though no one of the filaments of which it is composed would be sufficient for that purpose. It is a common observation, that it is unreasonable to require demonstration for things which do not admit of it. It is no less unreasonable to require reasoning of any kind for things which are known with- out reasoning. All reasoning must be grounded upon truths which are known without reasoning. In every branch of real knowledge there must be first principles whose truth is known intuitively, without reasoning, either probable or demonstrative. They are not grounded on reasoning, but all reasoning is grounded on them. It has been shewn, that there are first principles of necessary truths, and first principles of contingent truths. Demonstrative reason- ing is grounded upon the former, and pro- bable reasoning upon the latter. That we may not be embarrassed by the ambiguity of words, it is proper to observe, that there is a popular meaning of probable evidence, which ought not to be confounded with the philosophical meaning, above ex- plained. [691] In common language, probable evidence is considered as an inferior degree of evi- dence, and is opposed to certainty : so that what is certain is more than probable, and what is only probable is not certain. Phi- losophers consider probable evidence, not as a degree, but as a species of evidence, which is opposed, not to certainty, but tu another species of evidence, called demon- stration. Demonstrative evidence has no degrees ; but probable evidence, taken in the philo- sophical sense, has all degrees, from the very least to the greatest, which we call certainty. That there is such a city as Home, I am as certain as of any proposition in Euclid ; but the evidence is not demonstrative, but of that kind which philosophers call pro- bable. Yet, in common language, it would sound oddly to say, it is probable there is such a city as Rome, because it would imply some degree of doubt or uncertainty. Taking probable evidence, therefore, in the philosophical sense, as it is opposed to demonstrative, it may have any degrees of evidence, from the least to the greatest. I think, in most cases, we measure the degrees of evidence by the effect they have upon a, sound understanding, when com- prehended clearly and without prejudice. Every degree of evidence perceived by the mind, produces & proportioned degree of assent or belief. The judgment may be in perfect suspense between two contradictory opinions, when there is no evidence for either, or equal evidence for both. The least prepondera.ncy on one side inclines the judgment in proportion. Belief is mixed with doubt, more or less, until we come to the highest degree of evidence, when all doubt vanishes, and the belief is firm and immovable. This degree of evidence, the highest the human faculties can attain, we call certainty. [692] Probable evidence not only differs in kind from demonstrative, but is itself of different kinds. The chief of these I shall mention, without pretending to make a complete enumeration. The first kind is that of human testimony, upon which the greatest part of human knowledge is built. The faith of history depends upon it, as well as the judgment of solemn tribunals, with regard to men's acquired rights, and with regard to their guilt or innocence, when they are charged with crimes. A great part of the business of the judge, of counsel at the bar, of the historian, the critic, and the antiquarian, is to canvass and weigh this kind of evidence; and no man can act with common prudence in the ordinary occurrences of life, who has not some competent judgment of it. The belief we give to testimony, in many cases, is not solely grounded upon the vera- [690-692] CHAP. III.J OF PROBABLE REASONING. 483 city of the testifier. In a single testimony, we consider the motives a man might have to falsify. If there be no appearance of any such motive, much ore if there be motives on the other side, his testimony has weight independent of his moral character. If the testimony be circumstantial, we con- sider how far the circumstances agree to- gether, and with things that are known. It is so very difficult to fabricate a story which cannot be detected by a judicious examination of the circumstances, that it acquires evidence by being able to bear such a trial. There is an art in detecting false evidence in judicial proceedings, well known to able judges and barristers; so that I believe few false witnesses leave the bar without suspicion of their guilt. When there is an agreement of many witnesses, in a great variety of circum- stances, without the possibility of a previous concert, the evidence may he equal to that of demonstration. [693] A second kind of probable evidence, is the authority of those who are good judges of the point in question. The supreme court of judicature of the British nation, is often determined by the opinion of lawyers in a point of law, of physicians in a point of . medicine, and of other artists, in what re- lates to their several professions. And, in the common affairs of life, we frequently rely upon the judgment of others, in points of which we are not proper judges our- selves. A third kind of probable evidence, is that by which we recognise the identity of things and persons of our acquaintance. That two swords, two horses, or two persons, may be so perfectly alike as not to be distinguish- able by those to whom they are best known, cannot be shewn to be impossible. But we learn either from nature, or from experience, that it never happens ; or so very rarely, that a person or thing, well known to us, is immediately recognised without any doubt, when we perceive the marks or signs by which we were in use to distinguish it from all other individuals of the kind. This evidence we rely upon in the most important affairs of life ; and, by this evi- dence, the identity, both of things and of persons, is determined in courts of judica- ture. A fourth kind of probable evidence, is that which we have of men's future actions and conduct, from the general principles of action in man, or from our knowledge of the individuals. Notwithstanding the folly and vice that are to be found among men, there is a certain degree of prudence and probity which we rely upon in every man that is not insane. If it were not so, no man would be safe in the company of another, and there could be [693-6951 no society among mankind. If men were as much disposed to hurt as to do good, to lie as to speak truth, they could not live to- gether ; they would keep at as great dis- tance from one another as possible, and the race would soon perish. [694] We expect that men will take some care of themselves, of their family, friends, and reputation ; that they will not injure others without some temptation ; that they will have some gratitude for good offices, and some resentment of injuries. Such maxims with regard to human con- duet, are the foundation of all political rea- soning, and of common prudence in the con- duct of life. Hardly can a man form any project in public or in private life, which does not depend upon the conduct of other men, as well as his own, and which does not go upon the supposition that men will act such a part in such circumstances. This evidence may be probable in a very high degree ; but can never be demonstrative. The best concerted project may fail, and wise counsels may be frustrated, because some individual acted a part which it would have been against all reason to expect. Another kind of probable evidence, the counterpart of the last, is that by which we collect men's characters and designs from their actions, speech, and other external signs. We see not men's hearts, nor the prin- ciples by which they are actuated ; but there are external signs of their principles and dispositions, which, though not certain, may sometimes be more trusted than their professions ; and it is from external signs that we must draw all the knowledge we can attain of men's characters. The next kind of probable evidence I mention, is that which mathematicians call the probability of chances. We attribute some events to chance, be cause we know only the remote cause which must produce some one event of a num- ber ; but know not the more immediate cause which determines a particular event of that number in preference to the others. [695] I think all the chances about which we rea- son in mathematics are of this kind. Thus, in throwing a just die upon a table, we say it is an equal chance which of the six sides shall be turned up ; because neither the person who throws, nor the bystanders, know the precise measure of force and di- rection necessary to turn up any one side rather than another. There are here, there- fore six events, one of which must happen ; and as all are supposed to have equal pro- bability, the probability of any one side being turned up, the ace, for instance, is as one to the remaining number, five. The probability of turning up two ace* 2 12 484 ON THE INTELLECTUAL POWERS. [kssav VII. with two dice is as one to thirty-five ; because here there are thirty-six events, each of which has equal probability. Upon such principles as these, the doc- trine of chances has furnished a field of de- monstrative reasoning of great extent, al- though the events about which this reason- ing is employed be not necesssary, but con- tingent, and be not certain, but probable. This may seem to contradict a principle before advanced, that contingent truths are not capable of demonstration ; but it does not : for, in the mathematical reasonings about chance, the conclusion demonstrated, is not, that such an event shall happen, but that the probability of its happening bears such a ratio to the probability of its failing ; and this conclusion is necessary upon the suppositions on which it is grounded. The last kind of probable evidence I shall mention, is that by which the known laws of Nature have been discovered, and the effects which have been produced by them in former ages, or which may be expected in time to come. The laws of Nature are the rules by which the Supreme Being governs the world. We deduce them only from facts that fall within our own observation, or are properly attested by those who have observed them. [696] The knowledge of some of the laws of nature is necessary to all men in the con- duct of life. These are soon discovered even by savages. They know that fire burns, that water drowns, that bodies gra- vitate towards the earth. They know that day and night, summer and winter, regu- larly succeed each other. As far back as their experience and information reach, they know that these have happened regu- larly ; and, upon this ground, they are led, by the constitution of human nature, to ex- pect that they will happen in time to come, in like circumstances. The knowledge which the philosopher attains of the laws of Nature differs from that of the vulgar, not in the first principles on which it is grounded, but in its extent and accuracy. He collects with care the phsenomena that lead to the same conclu- sion, and compares them with those that seem to contradict or to limit it. He ob- serves the circumstances on which every pheenomenon depends, and distinguishes them carefully from those that are accident- ally conjoined with it. He puts natural bodies in various situations, and applies them to one another in various ways, on purpose to observe the effect ; and thus ac- quires from his senses a more extensive knowledge of the course of Nature in a short time, than could be collected by casual ob- servation in many ages. But what is the result of his laborious researches ? It is, that, as far as he has been able to observe, such things have always happened in such circumstances, and such bodies have always been found to have such properties. These are matters of fact, attested by sense, memory, and testimony, just as the few facts which the vulgar know are attested to them. And what conclusions does the philoso- pher draw from the facts he has collected ? They are, that like events have happened in former times in like circumstances, and will happen in time to come ; and these con- clusions are built on the very same ground on which the simple rustic concludes that the sun will rise to-morrow. [697] Facts reduced to general rules, and the consequences of those general rules, are all that we really know of the material world. And the evidence that such general rules have no exceptions, as well as the evidence that they will be the same in time to come as they have been in time past, can never be demonstrative. It is only that species of evidence which philosophers call probable. General rules may have exceptions or limit- ations which no man ever had occasion to observe. The laws of nature may be changed by him who established them. But we are led by our constitution to rely upon their continuance with as little doubt as if it was. demonstrable. I pretend not to have made a complete enumeration of all the kinds of probable evidence ; but those I have mentioned are sufficient to shew, that the far greatest part, and the most interesting part of our know- ledge, must rest upon evidence of this kind ; and that many things are certain for which we have only that kind of evidence which philosophers call probable. CHAPTER IV. of mr hume's scepticism with regard to REASON. In the " Treatise of Human Nature," book I. part iv. § 1, the author undertakes to prove two points : — First, That all that is called human knowledge (meaning de- monstrative knowledge) is only probability ; and, seoowui,, That this probability, when duly examined, evanishes by degrees, and leaves at last no evidence at all : so that, in the issue, there is no ground to believe anyone proposition rather than its contrary; and " all those are certainly fools who reason or believe anything." [698] According to this account, reason, that boasted prerogative of man, and the light of his mind, is an ignis faluus, which misleads the wandering traveller, and leaves him at last in absolute darkness. How 'unhappy is the condition of man ; [696-698] chap. iv.J OF MR HUME'S SCEPTICISM ABOUT REASON. 485 bom under a necessity of believing contra- dictions, -and of trusting to a guide who con- fesses herself to be a false one ! It is some comfort, that this doctrine can never be seriously adopted by any man in his senses. And after this author had shewn that " all the rules of logic require a total extinction of all belief and evidence," he himself, and all men that are not insane, must have believed many things, and yielded assent to the evidence which he had ex- tinguished. This, indeed, he is so candid as to acknow- ledge. " He finds himself absolutely and necessarily determined, to live and talk and act like other people in the common affairs of life. And since reason is incapable of dispelling these clouds, most fortunately it happens, that nature herself suffices to that purpose, and cures him of this philosophical melancholy and delirium." See § 7. This was surely a very kind and friendly interposition of nature ; for the* effects of this philosophical delirium, if carried into life, must have been very melancholy. But what pity is it, that nature, (what- ever is meant by that personage,) so kind in curing this delirium, should be so cruel as to cause it. Doth the same fountain ' send forth sweet waters and bitter ? Is it not more probable, that, if the cure was the work of nature, the disease came from another hand, and was the work of the philosopher ? [699] To pretend to prove by reasoning that there is no force in reason, does indeed look like a philosophical delirium. It is like a man's pretending to see clearly, that he himself and all other men are blind. A common symptom of delirium is, to - think that all, other men are fools or mad. This appears to have been the case of our author, who concluded, " That all those are certainly fools who reason or believe any- thing." Whatever was the cause of this delirium, it must be granted that, if it was real and not feigned, it was not to be cured by rea- soning ; for what can be more absurd than to attempt to convince a man by reasoning who disowns the authority of reason. It was, therefore, very fortunate that Nature found other means of curing it. It may, however, not be improper to inquire, whether, as the author thinks, it was produced by a just application of the rules of logic, or, as others may be apt to think, by the misapplication and abuse of them. First, Because we are fallible, the author infers that all knowledge degenerates into probability. That man, and probably every created being, is fallible ; and that a fallible being cannot have that perfect comprehension [699-7011 and assurance of truth which an infallible being has — I think ought to be granted. It becomes a fallible being to be modest, open to new .light, and sensible that, by some false bias, or by rash judging, he may be misled. If this be called a degree of scep- ticism, I cannot help approving of it, being persuaded that the man who makes the best use he can of the faculties which God has given him, without thinking them more per- fect than they really are, may have all the belief that is necessary in the conduct of life, and all that is necessary to his accept- ance with his Maker. [700] It is granted, then, that human judg- ments ought always to be formed with an humble sense of our fallibility in judging. This is all that can be inferred by the rules of logic from our being fallible. And if this be all that is meant by our know- ledge degenerating into probability, I know no person of a different opinion. But it may be observed, that the author here uses the word probability in a sense for which I know no authority but his own. Philosophers understand probability as op- posed to demonstration ; the vulgar as opposed to certainty ; but this author un- derstands it as opposed to infallibility, which no man claims. One who believes himself to be fallible may still hold it to be certain that two and two make four, and that two contradictory propositions cannot both be true. He may believe some things to be probable only, and other things to be demonstrable, with- out making any pretence to infallibility. If we use words in their proper meaning, it is impossible that demonstration should degenerate into probability from the imper- fection of our faculties. Our judgment can- not change the nature of the things about which we judge. What is really demon- stration, will still be so, whatever judgment we form concerning it. It may, likewise, be observed, that, when we mistake that foi demonstration which really is not, the con- sequence of this mistake is, not that de- monstration degenerates into probability, but that what we took to be demonstration is no proof at all ; for one false step in .a demonstration destroys the whole, but can- not turn it into another kind of proof. [701] Upon the whole, then, this first conclu- sion of our author, That the fallibility of human judgment turns all knowledge into probability, if understood literally, is absurd ; but, if it be only a figure of speech, and means no more but that, in all our judg- ments, we ought to be sensible of our falli- bility, and ought to hold our opinions with that modesty that becomes fallible crea- tures — which I take to be what the author meant — this, I think, nobody denies, nos 486 ON THE INTELLECTUAL POWERS. [essay VII was it necessary to enter into a laborious proof of it. One is never in greater danger of trans- gressing against the rules of logic than in attempting to prove what needs no proof. Of this we have an instance in this very case ; for the author begins his proof, that all human judgments are fallible, with af- firming that some are infallible. " In all demonstrative sciences," says he, " the rules are certain and infallible ; but when we apply them, our fallible and uncertain faculties are very apt to depart from them, and fall into error." He had forgot, surely, that the rules of demonstrative sciences are discovered by our fallible and uncertain faculties, and have no authority but that of human judg- ment. If they be infallible, some human judgments are infallible'; and there are many in various branches of human knowledge which have as good a claim to infallibility as the rules of the demonstrative sciences. We have reason here to find fault with our author for not being sceptical enough, as well as for a mistake in reasoning, when he claims infallibility to certain decisions of the human faculties, in order to prove that all their decisions are fallible. The second point which he attempts to prove is, That this probability, when duly examined, suffers a continual diminution, and at last a total extinction. The obvious consequence of this is, that no fallible being can have good reason to believe anything at all ; but let us hear the proof. [702] " In every judgment, we ought to cor- rect the first judgment derived from the nature of the object, by another judgment derived from the nature of the understand- ing. Beside the original uncertainty inher- ent in the subject, there arises another, derived from the weakness of the faculty which judges. Having adjusted these two uncertainties together, we are obliged, by our reason, to add a new uncertainty, de- rived from the possibility of error in the estimation we make of the truth and fidelity of our faculties. This is a doubt of which, if we would closely pursue our reasoning, we cannot avoid giving a decision. But this decision, though it should be favour- able to our preceding judgment, being founded only on probability, must weaken still farther our first evidence. The third uncertainty must, in like manner be criti- cised by a fourth, and so on without end. " Now, as every one of these uncertainties takes away a part of the original evidence, it must at last be reduced to nothing. Let our first belief be ever so strong, it must in- fallibly perish, by passing through so many examinations, each of which carries off somewhat of its force and vigour. No finite object can subsist under a decrease repeated in infinitum. " When I reflect on the natural fallibil- ity of my judgment, I have less confidence in my opinions than when I only consider the objects concerning which I reason. And when I proceed still farther, to turn the scru- tiny against every successive estimation I make of my faculties, all the rules of logic require a continual diminution, and at last a total extinction of belief and evidence." This is the author's Achillean argument against the evidence of reason, from which he concludes, that a man who would govern his belief by reason must believe nothing at all, and that belief is an act, not of the co- gitative, but of the sensitive part of our nature. [703] If there be any such thing as motion, (said an ancient Sceptic,*) the swift-footed Achilles could never overtake an old man in a journey. For, suppose the old man to set out a* thousand paces before Achilles, and that, while Achilles has travelled the thousand paces, the old man has gone five hundred ; when Achilles has gone the five hundred, the old man has gone two hun- dred and fifty ; and when Achilles has gone the two hundred and fifty, the old man is still one hundred and twenty-five before him. Repeat these estimations in infinitum, and you will still find the old man foremost ; therefore Achilles can never overtake him ; therefore there can be no such thing as motion. The reasoning of the modern Sceptic against reason is equally ingenious, and equally convincing. Indeed, they have a great similarity. If we trace the journey of Achilles two thousand paces, we shall find the very point where the old man is overtaken. But this short journey, by dividing it into an infinite number of stages, with correspond- ing estimations, is made to appear infinite. In like manner, our author, subjecting every judgment to an infinite number of successive probable estimations, reduces the evidence to nothing. To return then to the argument of the modern Sceptic. I examine the proof of a theorem of Euclid. It appears to me to be strict demonstration. But I may have overlooked some fallacy; therefore I ex- amine it again and again, but can find no flaw in it. I find all that have examined it agree with me. I have now that evidence of the truth of the proposition which I and all men call demonstration, and that belief of it which we call certainty. [704] Here my sceptical friend interposes, and assures me, that the rules of logic reduce * Zeno Eleates. He is improperly called, simpli- nter, ■ Sceptic H. ' [702-701] ouap. iv. J OF Mil HUME'S SCEPTICISM ABOUT REASON. 487 this demonstration to no evidence at all. 1 am willing to hear what step in it he thinks fallacious, and why. He makes no objec- tion to any part of the demonstration, but pleads my fallibility in judging. I have made the proper allowance for this already, by being open to conviction. But, says he, there are two uncertainties, the first inherent in the subject, which I have already shewn to have only probable evidence ; the second arising from the weakness of the faculty that judges. I answer, it is the weakness of the faculty only that reduces this demonstra- tion to what you call probability. You must not therefore make it a second uncer- tainty; for it is the same with the first. To take credit twice in an account for the same article is not agreeable to the rules of logic. Hitherto, therefore, there is but one uncertainty— to wit, my fallibility in judging. But, says my friend, you are obliged by reason to add a new uncertainty, derived from the possibility of error in the estima- tion you make of the truth and fidelity of your faculties. I answer — This estimation is ambiguously ex- pressed ; it may either mean an estimation of my liableness to err by the misapplica- tion and abuse of my faculties ; or it may mean an estimation of my liableness to err by conceiving my faculties to be true and faithful, while they may be false and falla- cious in themselves, even when applied in the best manner. I shall consider this estimation in each of these senses. If the first be the estimation meant, it is true that reason directs us, as fallible crea- tures, to carry along with us, in all our judgments, a sense of our fallibility. It is true also, that we are in greater danger of erring in some cases, and less in others ; and that this danger of erring may, accord- ing to the circumstances of the case, admit of an estimation, which we ought likewise to carry along with us in every judgment we form. [705] When a demonstration is short and plain ; when the point to be proved does not touch our interest or our passions ; when the faculty of judging, in such cases, has acquired strength by much exercise — there is less danger of erring ; when the contrary circumstances take place, there is more. In the present case, every circumstance is favourable to the j udgment I have formed. There cannot be less danger of erring in any case, excepting, perhaps, when I judge of a self-evident axiom. The Sceptic farther urges, that this deci- sion, though favourable to my first judg- ment, being founded only on probability, must still weaken the evidence of that judg- ment. Here I cannot help being of a quite con- 1705, 7061 trary opinion ; nor can I imagine how an ingenious author could impose upon himself so grossly ; for surely he did not intend to impose upon his reader. After repeated examination of a propo- sition of Euclid, I judge it to be strictly demonstrated ; this is my first judgment. But, as I am liable to err from various causes, I consider how far I may have been misled by any of these causes in this judg- ment. My decision upon this second point is favourable to my first judgment, and therefore, as I apprehend, must strengthen it. To say that this decision, because it is only probable, must weaken the first evi- dence, seems to me contrary to all rules of logic, and to common sense. The first judgment may be compared to the testimony of a credible witness ; the second, after a scrutiny into the character of the witness, wipes off every objection that can be-made to it, and therefore surely must confirm and not weaken his testi- mony. [706] But let us suppose, that, in another case,s I examine my first judgment upon some point, and find that it was attended with unfavourable circumstances, what, in rea- son, and according to the rules of logic, ought to be the effect of this discovery ? The effect surely will be, and ought to be, to make me less confident in my first judgment, until I examine the point anew in more favourable circumstances. If it be a matter of importance, I return to weigh the evidence of my first judgment. If it was precipitate before, it must now be deliberate in every point. If, at first, I was in passion, I must now be cool. If I had an interest in the decision, I must place the interest on the other side. It is evident that this review of the sub- ject may confirm my first judgment, not- withstanding the suspicious circumstances that attended it. Though the judge was biassed or corrupted, it does not follow that the sentence was unjust. The rectitude of the decision does not depend upon the cha- racter of the judge, but upon the nature of the case. From that only, it must be deter- mined whether the decision be just. The circumstances that rendered it suspicious are mere presumptions, which have no force against direct evidence. Thus, I have considered the effect of this estimation of our liableness to err in our first judgment, and have allowed to it all the effect that reason and the rules of logic permit. In the case I first supposed, and in every case where we can discover no cause of error, it affords a presumption in favour of the first judgment. In other cases, it may afford a presumption against it. But the rules of logic require, that we should not judge by presumptions, xhere 488 ON THE INTELLECTUAL, POWEUS. fESSAY VII. we have direct evidence. The effect of an unfavourable presumption should only be, to make us examine the evidence with the greater care. • [707] The sceptic urges, in the last place, that this estimation must be subjected to another estimation, that to another, and so on, in in- finitum ; and as every new estimation takes away from the evidence of the first judg- ment, it must at last be totally annihilated. I answer, first, It has been shewn above, that the first estimation, supposing it un- favourable, can only afford a presumption against the first judgment ; the second, upon the same supposition, will be only the presumption of a presumption ; and the third, the presumption that there is a pre- sumption of a presumption. This infinite series of presumptions resembles an infinite series of quantities, decreasing in geome- trical proportion, which amounts only to a finite sum. The infinite series of stages of Achilles'sjourney after the old man, amounts only to two thousand paces ; nor can this infinite series of presumptions outweigh one solid argument in favour of the first judg- ment, supposing them all to be unfavour- able to it. Secondly, I have shewn, that the estima- tion of our first judgment may strengthen it ; and the same thing may be said of all the subsequent estimations. It would, there- fore, be as reasonable to conclude, that the first judgment will be brought to infallible certainty when this series of estimations is wholly in its favour, as that its evidence will be brought to nothing by such a series supposed to be wholly unfavourable to it. But, in reality, one serious and cool re- examination of the evidence by which our first judgment is supported, has, and in reason ought tohavemore force tostrengthen or weaken it, than an infinite series of such estimations as our author requires. Thirdly, I know no reason nor rule in logic, that requires that such a series of estimations should follow every particular judgment. [708] A wise man, who has practised reasoning, knows that he is fallible, and carries this conviction along with him in every judg- ment he forms. He knows likewise that he is more liable to err in some cases than in others. He has a scale in his mind, by which he estimates his liableness to err, and by this he regulates the degree of his assent in his first judgment upon any point. ■ The author's reasoning supposes, that a man, when he forms his first judgment, conceives himself to be infallible ; that by a second and subsequent judgment, he dis- covers that he is not infallible ; and that by a third judgment, subsequent to the second, he estimates his liableness to err in such a case as the present. If the man proceed in this order, I grant, that his second judgment will, with good reason, bring down the first from supposed infallibility to fallibility ; and that his third judgment will, in some degree, either strengthen or weaken the first, as it is cor- rected by the second. But every man of understanding proceeds in a contrary order. When about to judge in any particular point, he knows already that he is not infallible. He knows what are the cases in which he is most or least liable to err. The conviction of these things is always present to his mind, and influences the degree of his assent in his first judg- ment, as far as to him appears reasonable. If he should afterwards find reason to suspect his first judgment, and desires to have all the satisfaction his faculties can give, reason will direct him not to form such a series of estimations upon estima- tions, as this author requires, but to examine the evidence of his first judgment carefully and coolly ; and this review may very reason- ably, according to its result, eitherstrengtben or weaken, or totally overturn his first judgment. [709] This infinite series of estimations, there- fore, is not the method that reason directs, in order to form our judgment in any case. It is introduced without necessity, without any use but to puzzle the understanding, and to make us think, that to judge, even in the simplest and plainest cases, is a mat- ter of insurmountable difficulty and endless labour ; just as the ancient Sceptic, to make a journey of two thousand paces appear endless, divided it into an infinite number of stages. But we observed, that the estimation which our author requires, may admit of another meaning, which, indeed, is more agreeable to the expression, but inconsist- ent with what he advanced before. By the possibility of error in the estima- tion of the truth and fidelity of our faculties, may be meant, that we may err by esteem- ing our faculties true and faithful, while they may. be false and fallacious, even when used according to the rules of reason and logic. If this be meant, I answer, first, That the truth and fidelity of our faculty of judg- ing is, and must be taken for granted in every judgment and in every estimation. If the sceptic can seriously doubt of the truth and fidelity of his faculty of judging when properly used, and suspend his judg- ment upon that point till he finds proof, his scepticism admits of no cure by reasoning, and he must even continue in it until he have new faculties given him, which shall have authority to sit in judgment upon the old. Nor is there any need of an endless succession of doubts upon this subject ; for the first puts au end to all judgment and chap. iv.J OF MR HUME'S SCEPTICISM ABOUT ItEASON. 489 reasoning, and to the possibility of convic- tion by that means. The sceptic has here got possession of a stronghold, which is im- pregnable to reasoning, and we must leave him in possession of it till Nature, by other means, makes him give it up. [710] Secondly, I observe, that this ground of scepticism, from the supposed infidelity of our faculties, contradicts what the author before advanced in this very argument — to wit, that " the rules of the demonstrative sciences are certain and infallible, and that truth is the natural effect of reason, and that error arises from the irruption of other causes." But, perhaps, he made these concessions unwarily. He is, therefore, at liberty to retract thein, and to rest his scepticism upon this sole foundation, That no reasoning can prove the truth and fidelity of our faculties- Here he stands upon firm ground ; for it is evident that every argument offered to prove the truth and fidelity of our faculties, takes for granted the thing in question, and is, therefore, that kind of sophism which logicians call pp.titio principii. All we would ask of this kind of sceptic is, that he would be uniform and consistent, and that his practice in lile do not belie his profession of scepticism, with regard to the fidelity of his faculties ; for the want of faith, as well as faith itself, is best shewn by works. If a sceptic avoid the fire as much as those who believe it dangerous to go into it, we can hardly avoid thinking his scepticism to be feigned, and not real. Our author, indeed, was aware, that neither his scepticism nor that of any other person, was able to endure this trial, and, therefore, enters a caveat against it. " Neither I," says he, " nor any other per- son was ever sincerely and constantly of that opinion. Nature, by an absolute and uncontrollable necessity, has determined us to judge, as well as to breathe and feel. My intention, therefore," says he, " in display- ing so carefully the arguments of that fan- tastic sect, is only to make the reader sen- sible of the truth of my hypothesis, that all our reasonings concerningcausesand effects, are derived from nothing but custom, and that belief is more properly an act of the [710-713] sensitive than of the cogitative part of our nature." [711] We have before considered the first part of this hypothesis, Whether our reasoning about causes be derived only from custom ? The other part of the author's hypothesis here mentioned is darkly expressed, thougli the expression seems to be studied, as it is put in Italics. It cannot, surely, mean that belief is not an act of thinking. It is not, therefore, the power of thinking that he calls the cogitative part of our nature. Neither can it be the power of judging, for all belief implies judgment ; and to believe a proposition means the same thing as to judge it to be true. It seems, therefore, to be the power of reasoning that he calls the cogitative part of our nature. If this be the meaning, I agree to it in part. The belief of first principles is not an act of the reasoning power ; for all rea- soning must be grounded upon them. We judge them to be true, and believe them without reasoning. But why this power of judging of first principles should be called the sensitive part of our nature, I do not understand. As our belief of first principles is an act of pure judgment without reasoning ; so our belief of the conclusions drawn by rea- soning from first principles, may, I think, be called an act of the reasoning faculty. [712] Upon the whole, I see only two conclu- sions that can be fairly drawn from this profound and intricate reasoning against reason. The first is, That we are fallible in all our judgments and in all our reason- ings. The second, That the truth and fidelity of our faculties can never be proved by reasoning ; and, therefore, our belief of it cannot be founded on reasoning. If the last be what the author calls his hypothesis, I subscribe to it, and think it not an hypo- thesis, but a manifest truth ; though I con- ceive it to be very improperly expressed, by saying that belief is more properly an act of the sensitive than of the cogitative part of our nature. * [713] * In the preceding strictures, the Sceptic *«again too often assailed a. a Dogmatist. See above p. 4W note *.— H. 490 ON THE INTELLECTUAL POWERS. (.essay viii. ESSAY VIII. OF TASTE. CHAPTER I. OP TASTE IN GENERAL. That power of the mind liy which we are capable of discerning and relishing the beauties of Nature, and whatever is excel- lent in the fine arts, is called taste. The external sense of taste, by which we distinguish and relish the various kinds of food, has given occasion to a metaphorical application of its name to this internal power of the mind, by which we perceive what is beautiful and what is deformed or defective in the various objects that we contemplate. Like the taste of the palate, it relishes some things, is disgusted with others ; with regard to many, is indifferent or dubious ; and is considerably influenced by habit, by associations, and by opinion. These obvious analogies between external and internal taste, have led men, in all ages, and in all or most polished languages,* to give the name of the external sense to this power of discerning what is beautiful with pleasure, and what is ugly and faulty in its kind with disgust. [714] In treating of this as an intellectual power of the mind, I intend only to make some observations, first on its nature, and then on its objects. 1 . In the external sense of taste, we are led by reason and reflection to distinguish between the agreeable sensation we feel, and the quality in the object which occasions it. Both have the same name, and on that ac- count are apt to be confounded by the vulgar, and even by philosophers. The sensation I feel when I taste any sapid body is in my mind; but there is a real quality in the body which is the cause of this sensation. These two things have the same name in language, not from any similitude in their nature, but because the one is the sign of the other, and because there is little occa- sion in common life to distinguish them. This was fully explained in treating of the secondary qualities of bodies. The reason of taking notice of it now is, that the in- ternal power of taste bears a great analogy in this respect to the external. When a beautiful object is before us, we * 'lllis is hardly correct. — H. may distinguish the agreeable emoticn it produces in us, from the quality of the ob- ject which causes that emotion. When I hear an air in music that pleases me, I say, it is fine, it is excellent. This excellence is not in me ; it is in the music. But the pleasure it gives is not in the music ; it is in me. Perhaps I cannot say what it is in the tune that pleases my ear, as I cannot say what it is in a sapid body that pleases my palate ; but there is a quality in the sapid body which pleases my palate, and I call it a delicious taste ; and there is a quality in the tune that pleases my taste, and I call it a fine or an excellent air. This ought the rather to be observed, because it is become a fashion among mo- dern philosophers, to resolve all our percep- tions into mere feelings or sensations in the person that perceives, without anything corresponding to those feelings in the ex- ternal object. [715] According to those philosophers, there is no heat in the fire, no taste in a sapid body ; the taste and the heat being only in the person that feels them.* In like manner, there is no beauty in any object whatsoever ; it is only a sens- ation or feeling in the person that per- ceives it. The language and the common sense of mankind contradict this theory. Even those who hold it, find themselves obliged to use a language that contradicts it. I had occa- sion to shew, that there is no solid founda- tion for it when applied to the secondary qualities of body ; and the same arguments shew equally, that it has no solid foundation when applied to the beauty of objects, or to any of those qualities that are perceived by a good taste. But, though some of the qualities that please a good taste resemble the secondary qualities of body, and therefore may be called occult qualities, as we only feel their effect, and have no more knowledge of the cause, hut that it is something which is adapted by nature to produce that effect — this is not always the case. Our judgment of beauty is in many cases more enlightened. A work of art may appear beautiful to the most ignorant, even to a child. It pleases, but he knows not * But see, above, p. 205, b, role *, and p. 310, b, note +. — H. [714, 715] OHAP. I. I OF TASTE IN GENERAL. 491 why. To one who understands it perfectly, and perceives how every part is fitted with exact judgment to its end, the beauty is not mysterious ; it is perfectly comprehended ; and he knows wherein it consists, as well as how it affects him. 2. We may observe, that, though all the tastes* we perceive by the palate are either agreeable or disagreeable, or indifferent ; yet, among, those that are agreeable, there is great diversity, not in degree only, but in kind. And, as we have not generical names for all the different kinds of taste, we dis- tinguish them by the bodies in which they are found. [716] In like manner, all the objects of our internal taste are either beautiful, or dis- agreeable, or indifferent ; yet of beauty 'there is a great diversity, not only of degree, but of kind. The beauty of a demonstration, the beauty of a poem, the beauty of a palace, the beauty of a piece of music, the beauty of a fine woman, and many more that might be named, are different kinds of beauty ; nnd we have no names to distinguish them but the names of the different objects to which they belong. As there is such diversity in the kinds of beauty as well as in the degrees, we need not think it strange that philosophers have gone into different systems in analysing it, and enumerating its simple ingredients. They have made many just observations on the subject ; but, from the love of simplicity, have reduced it to fewer principles than the nature of the thing will permit, having had in^heir eye some particular kinds of beauty, while they overlooked others. There are moral beauties as well as na- tural ; beauties in the objects of sense, and in intellectual objects ; in the works of men, and in the works of God ; in things inani- mate, in brute animals, and in rational beings ; in the constitution of the body of man, and in the constitution of his mind. There is no real excellence which has not its beauty to a discerning eye, when placed in a proper point of view ; and it is as diffi- cult to enumerate the ingredients of beauty as the ingredients of real excellence. 3. The taste of the palate may be accounted most just and perfect, when we relish the things that are fit for the nourishment of the body, and are disgusted with things of a contrary nature. The manifest intention of nature in giving us this sense, is, that we may discern what it is fit for us to eat and to drink, and what it is not. Brute animals are directed in the choice of their food merely by their taste. [717] Led by this guide, they choose the food that nature intended for them, and seldom make mis- takes, unless they be pinched by hunger, or deceived by artificial compositions. In in- fants likewise the taste is commonly sound r 716-7I8j and uncorrupted, and of the simple produc- tions of nature they relish the things that are most wholesome. In like manner, our internal taste ought to be accounted most just and perfect, when we are pleased with things that are most excellent in their kind, and displeased with the contrary. The intention of nature is no less evident in this internal taste than in the external. Every excellence has a real beauty and charm that makes it an agreeable object to those who have the faculty of discerning its beauty ; and this faculty is what we call a good taste. A man who, by any disorder in his mental powers, or by bad habits, has contracted a relish for what has no real excellence, or what is deformed and defective, has a de- praved taste, like one who finds a more agreeable relish in ashes or cinders than in the most wholesome food. As we must ac- knowledge the taste of the palate to be de- praved in this case, there is the same reason to think the taste of the mind depraved in the other. There is therefore a just and rational taste, and there is a depraved and corrupted taste. For it is too evident, that, by bad education, bad habits, and wrong associa- tions, men may acquire a relish for nasti- ness, for rudeness, and ill-breeding, and for many other deformities. To say that such a taste is not vitiated, is no less absurd than to say, that the sickly girl who delights in eating charcoal and tobacco-pipes, has as just and natural a taste as when she is in perfect health. 4. The force of custom, of fancy, and of casual associations, is very great both upon the external and internal taste. An Eski- maux can regale himself with a draught of whale-oil, and a Canadian can feast upon a dog. A Kamschatkadale lives upon putrid fish, and is sometimes reduced to eat thy bark of trees. The taste of rum, or of green tea, is at first as nauseous as that of ipeca- cuan, to some persons, who may be brought by use to relish what they once found so disagreeable. [718] When we see such varieties in the taste of the palate produced by custom and as- sociations, and some, perhaps, by constitu- tion, we may be the less surprised that the same causes should produce like varieties in the taste of beauty ; that the African should esteem thick lips and a flat nose ; that other nations should draw out their ears, till they hang over their shoulders; that in one nation ladies should paint their faces, and in another should make them shine with grease. 5. Those who conceive that there is no standard in nature by which taste may be regulated, and that the common proverb, " That there ought to be no dispute about 492 ON THE INTELLECTUAL TOWERS. [essav vm. taste," is to be taken iu the utmost latitude, go upon slender and insufficient ground. The same arguments might be used with equal force against any standard of truth. Whole nations by the force of prejudice are brought to believe the grossest absurdi- ties ; and why should it be thought that the taste is less capable of being perverted than the judgment ? It must indeed be acknow- ledged, that men differ more in the faculty of taste than in what we commonly call judgment ; and therefore it may be expected that they should be more liable to have their taste corrupted in matters of beauty and deformity, than their judgment in matters of truth and error. If we make due allowance for this, we shall see that it is as easy to account for the variety of tastes, though there he in nature a standard of true beauty, and con- sequently of good taste, as it is to account for the variety and contrariety of opinions, though there be in nature a standard of of truth, and, consequently, of right judg- ment. [719] 6. Nay, if we speak accurately and strictly, we shall find that, in every opera- tion of taste, there is judgment implied. When a man pronounces a poem or a palace to be beautiful, he affirms something of that poem or that palace ; and every affirmation or denial expresses judgment. For we cannot better define judgment, than by saying that it is an affirmation or denial of one thing concerning another. I had occasion to shew, when treating of judg- ment, that it is implied in every perception of our external senses. There is an imme- diate conviction and belief of the existence of the quality perceived, whether it be colour, or sound, or figure ; and the same thing holds in the perception of beauty or deformity. If it be said that the perception of beauty is merely a feeling in the mind that per- ceives, without any belief of excellence in the object, the necessary consequence of this opinion is, that when I say Virgil's " Georgics" is a beautiful poem, I mean not to say anything of the poem, but only some- thing concerning myself and my feelings. Why should I use a language that expresses the contrary of what I mean ? My language, according to the necessary rules of construction, can bear no other meaning but this, that there is something in the poem, and not in me, which I call beauty. Even those who hold beauty to be merely a feeling in the person that per- ceives it, find themselves under a necessity of expressing themselvesas if beauty were s olely a quality of the object, and not of the percipient. No reason can be given why all man- kind should express themselves thus, but that they believe what they say. It is there- fore contrary to the universal sense of mankind, expressed by their language, that beauty is not really in the object, but is merely a feeling in the person who is said to perceive it. Philosophers should be very cautious in opposing the common sense of mankind ; for, when they do, they rarely miss going wrong. [720] Our judgment of beauty is not indeed a dry and unaffecting judgment, like that- of a mathematical or metaphysical truth. By the constitution of our nature, it is accom- panied with an agreeble feeling or emotion, for which we have no other name but the sense of beauty. This sense of beauty, like the perceptions of our other senses, implies not only a feeling, but an opinion of some quality in the object which occasions that feeling. In objects that please the taste, we always judge that there is some real excellence, some superiority to those that do not please. In some cases, that superior ex- cellence is distinctly perceived, and can be pointed out; in other cases, we have only a general notion of some excellence which we cannot describe. Beauties of the former kind may be compared to the primary qualities perceived by the external senses ; those of the latter kind, to the secondary. 7. Beauty or deformity in an object, re- sults from its nature or structure. To per- ceive the beauty, therefore, we must per- ceive the nature or structure from which it results. In this the internal sense differs from the external. Our external senses may discover qualities which do not depend upon any antecedent perception. Thus, I can hear the sound of a bell, though I never perceived anything else belonging to it. But it is impossible to perceive the beauty of an object without perceiving the object, or, at least, conceiving it. On this account, Dr Hutcheson called the senses of beauty and harmony reflex or secondary senses ; because the beauty cannot be perceived unless the object be perceived by some other power of the mind. Thus, the sense of harmony and melody in sounds supposes the external sense of hearing, and is a kind of secondary to it. A man born deaf may be a good judge of beauties of another kind, but can have no notion of melody or har- mony. The like may be said of beau- ties in colouring and in figure, which can never he perceived without the senses by which colour and figure are perceived. [721] [719-721J OHAP. II.'] OF NOVELTY. 492 CHAPTER II. OP THE OBJECTS OF TASTE ; AND, FIRST, OF NOVELTY. A philosophical analysis of the objects of taste is like applying the anatomical knife to a fine face. The design of the philoso- pher, as well as of the anatomist, is not to gratify taste, but to improve knowledge. The reader ought to be aware of this, that he may not entertain an expectation in which he will be disappointed. By the objects of taste, I mean those qualities or attributes of things which are, by Nature, adapted to please a good taste. Mr Addison, and Dr Akenside after him, have reduced them to three— to wit, novelty, grandeur, and beauty. This division is sufficient for all I intend to say upon the subject, and therefore I shall adopt it — observing only, that beauty is often taken hi so extensive a sense as to comprehend all the objects of taste ; yet all the authors I have met with, who have given a division of the objects of taste, make beauty one species. I take the reason of this to be, that we have specific names for some of the quali- ties that please the taste, but not for all ; and therefore all those fall under the gene- ral name of beauty, for which there is no specific name in the division. There are, indeed, so many species of beauty, that it would be as difficult to enu- merate them perfectly, as to enumerate all the tastes we perceive by the palate. Nor does there appear to me sufficient reason for making, as some very ingenious authors have done, as many different internal senses as there are different species of beauty or deformity. [722] The division of our external senses is taken from the organs of perception, and not from the qualities perceived. We have not the same means of dividing the inter- nal ; because, though some kinds of beauty belong only to objects of the eye, and others to objects of the ear, there are many which we cannot refer to any bodily organ ; and therefore I conceive every division that has been made of our internal senses to be in some degree arbitrary. They may be made more or fewer, according as we have dis- tinct names for the various kinds of beauty and deformity; and I suspect the most copious languages have not names for them all. Novelty is not properly a quality of the thing to which we attribute it, far less is it a sensation in the mind to which it is new ; it is a relation which the thing has to the knowledge of the person. What is new to one man, may not be so to another ; [722, 723] what is new this moment, may be familiar to the same person some time hence. When an object is first brought to our know- ledge, it is new, whether it be agreeable or not. It is evident, therefore, with regard to novelty, (whatever may be said of other objects of taste,) that it is not merely a sensation in the mind of him to whom the thing is new ; it is a real relation which the thing has to his knowledge at that time. But we are so constituted, that what is new to us commonly gives pleasure upon that account, if it be not in itself disagree- able. It rouses our attention, and occa- sions an agreeable exertion of our facul- ties. The pleasure we receive from novelty in objects has so great influence in human life, that it well deserves the attention of philosophers ; and several ingenious authors — particularly Dr Gerard, in his " Essay on Taste" — have, I think, successfully account- ed for it, from the principles of the human constitution. [723] We can perhaps conceive a being so made, that his happiness consists in a con- tinuance of the same unvaried sensations or feelings, without any active exertion on his part. Whether this be possible or not, it is evident that man is not such a being ; his good consists in the vigorous exertion of his active and intellective powers upon their proper objects ; he is made for action and progress, and cannot be happy without it ; his enjoyments seem to be given by Nature, not so much for their own sake, as to encourage the exercise of his various powers. That tranquillity of soul in which some place human happiness, is not a dead rest, but a regular progressive motion. Such is the constitution of man by the appointment of Nature. This constitution is perhaps a part of the imperfection of our nature ; but it is wisely adapted to our state, which is not intended to be stationary, but progressive. The eye is not satiated with seeing, nor the ear with hearing; something is always wanted. Desire and hope never cease, but remain to spur us on to something yet to be acquired; and, if they could cease, human happiness must end with them. That our desire and hope be properly directed, is our part ; that they can never be extinguished, is the work of Nature. It is this that makes human life so busy a scene. Man must be doing something, good or bad, trifling or important ; and he must vary the employment of his facul- ties, or their exercise will become languid, and the pleasure that attends it sicken of course. The notions of enjoyment, and of activity, 494 ON THE INTELLECTUAL POWERS. [essay viii. considered abstractly, are no doubt very different, and we cannot perceive a neces- sary connection between them. But, in our constitution, they are so connected by the wisdom of Nature, that they must go hand in hand ; and the first must be led and supported by the last. [724] An object at first, perhaps, gave much pleasure, while attention was directed to it with vigour. But attention cannot be long . confined to one unvaried object, nor can it be carried round in the same narrow circle. Curiosity is a capital principle in the human constitution, and its food must be what is in some respect new. What is said of the Athenians may, in some degree, he applied to all mankind, That their time is spent in hearing, or telling, or doing some new thing. Into this part of the human constitution, I think, we may resolve the pleasure we have from novelty in objects. Curiosity is commonly strongest in child- ren and in young persons, and accordingly novelty pleases them most. In all ages, in proportion as novelty gratifies curiosity, and occasions a vigorous exertion of any of our mental powers in attending to the new ob- ject, in the same proportion it gives plea- sure. In advanced life, the indolent and inactive have the strongest passion for news, as a relief from a painful vacuity of thought. But the pleasure derived from new objects, in many cases, is not owing solely or chiefly to their being new, but to some other cir- cumstance that gives them value. The new fashion in dress, furniture, equipage, and other accommodations of life, gives plea- sure, not so much, as I apprehend, because it is new, as because it is a sign of rank, and distinguishes a man from the vulgar. In some things novelty is due, and the want of it a real imperfection. Thus, if an author adds to the number of books with which the public is already overloaded, we expect from him something new ; and, if he says nothing but what has been said before in as agreeable a manner, we are justly disgusted. [725] When novelty is altogether separated from the conception of worth and utility, it makes but a slight impression upon a truly correct taste. Every discovery in nature, in the arts, and in the sciences, has a real value, and gives a rational pleasure to a good taste. But things that have nothing to recommend them but novelty, are fit only to entertain children, or those who are distressed from a vacuity of thought. This quality of objects may therefore be com- pared to the cypher in arithmetic, which adds greatly to the value of significant figures ; but, when put by itself, signifies nothing at all. CHAPTER III. Or GEANDEUB. TnE qualities which please the taste are not more various in themselves than are the emotions and feelings with which they affect our minds. Things new and uncommon affect us with a pleasing surprise, which rouses and invi- gorates our attention to the object. But this emotion soon flags, if there is nothing but novelty to give it continuance, and leaves no effect upon the mind. The emotion raised by grand objects is awful, solemn, and serious. Of all objects of contemplation, the Su- preme Being, is the most grand. His eternity, his immensity, his irresistible power, his infinite knowledge and unerring wisdom, his inflexible justice and rectitude, his su- preme government, conducting all the movements of this vast universe to the no- blest ends and in the wisest manuer — are objects which fill the utmost capacity of the soul, and reach far beyondits comprehension. The emotion which this grandest of all objects raises in the human mind, is what we call devotion ; a serious recollected tem- per, which inspires magnanimity, and dis- poses to the most heroic acts of virtue. [726} The emotion produced by other objects which may be called grand, though iu an inferior degree, is, in its nature and in its effects, similar to that of devotion. It dis- poses to seriousness, elevates the mind above its usual state, to a kind of enthusi- asm, and inspires magnanimity, and a con- tempt of what is mean. Such, I conceive, is the emotion which the contemplation of grand objects raises in us. We are next to consider what this grandeur in objects is. To me it seems to be nothing else but such a degree of excellence, in one kind or another, as merits our admiration. There are some attributes of mind which have a real and intrinsic excellence, com- pared with their contraries, and which, in every degree, are the natural objects of esteem, but, in an uncommon degree, are ob- jects of admiration. We put a value upon them because they are intrinsically valuable and excellent. The spirit of modern philosophy would indeed lead us 1 to think, that the worth and value we put upon things is only a sensation in our minds, and not anything inherent in the object ; and that we might have been so constituted as to put the highest value upon the things which we now despise, and to despise thequalities which we now highly esteem. [7S24-726J CHAP. 111.] OF GRANDEUR. 495 It gives me pleasure to observe, that Dr Price, in his " Review of the Questions concerning Morals," strenuously opposes this opinion, as well as that which resolves moral right and wrong into a sensation in the mind of the spectator. That judicious author saw the consequences which these opinions draw after them, and has traced them to their source — to wit, the account given by Mr Locke, and adopted by the gen- erality of modern philosophers, of the ori- gin of all our ideas, which account he shews to be very defective. [727] This proneness to resolve everything into feelings and sensations, is an extreme into which we have been led by the desire of avoiding an opposite extreme, as common in the ancient philosophy. At first, men are prone by nature and by habit to give all their attention to things external. Their notions of the mind, and its operations, are formed from some analogy they bear to objects of sense ; and an ex- ternal existence is ascribed to things which are only conceptions or feelings of the mind. This spirit prevailed much in the philo- sophy both of Plato and of Aristotle, and produced the mysterious notions of eternal and self-existent ideas, of materia prima, of substantial forms, and others of the like nature. From the time of Des Cartes, philosophy took a contrary turn. That great man dis- covered, that many things supposed to have an externalexistence, were only conceptions or feelings of the mind. This track has been pursued by his successors to such an extreme as to resolve everything into sens- ations, feelings, and ideas in the mind, and to leave nothing external at all. The Peripatetics thought that heat and cold which we feel to be qualities of external objects. The moderns make heat and cold to be sensations only, and allow no real quality of body to be called by that name : and the same judgment they have formed with regard to all secondary qualities. So far Des Cartes and Mr Locke went. Their successors being put into this track of converting into feelings things that were believed to have an externalexistence, found that extension, solidity, figure, and all the primary qualities of body, are sensations or feelings of the mind ; and that the material world is a pheenomenon only, and has no existence but in our mind. [728] It was then a very natural progress to con- ceive, that beauty, harmony, and grandeur, the objects of taste, as well as right and wrong, the objects of the moral faculty, are nothing but feelings of the mind. Those who are acquainted with the writings of modern philosophers, can easily trace this doctrine of feelings, from Des [727-729] Cartes down to Mr Hume, who put the finishing stroke to it, by making truth and error to be feelings of the mind, and belief to be an operation of the sensitive part of our nature. To return to our subject, if we hearken to the dictates of common sense, we must be convinced that there is real excellence in some things, whatever our feelings or our constitution be. It depends no doubt upon our constitu- tion, whether we do or do not perceive ex- cellence where it really is : but the object has its excellence from its own constitution, and not from ours. The common judgment of mankind in this matter sufficiently appears in the language of all nations, which uniformly ascribes ex- cellence, grandeur, and beauty to the object, and not to the mind that perceives it. And I believe in this, as in most other things, we shall find the common judgment of man- kind and true philosophy not to be at va- riance. Is not power in its nature more excel- lent than weakness ; knowledge than igno- rance ; wisdom than folly ; fortitude than pusillanimity ? Is there no intrinsic excellence in self- command, in generosity, in public spirit ? Is not friendship a better affection of mind than hatred, a noble emulation than envy ? [729] Let us suppose, if possible, a being so constituted as to have a high respect for ignorance, weakness, and folly; to venerate cowardice, malice, and envy, and to hold the contrary qualities in contempt ; to have an esteem for lying and falsehood ; and to love most those who imposed upon him, and used him worst. Could we believe such a constitution to be anything else than madness and delirium ? It is impossible. We can as easily conceive a constitution, by which one should perceive two and three to make fifteen, or a part to be greater than the whole. Every one who attends to the operations of his own mind will find it to be certainly true, as it is the common belief of mankind, that esteem is led by opinion, and that every person draws our esteem, as far only as he appears either to reason or fancy to be amiable and worthy. There is therefore a real intrinsic excel- lence in some qualities of mind, as in power, knowledge, wisdom, virtue, magnanimity. These, in every degree, merit esteem ; but in an uncommon degree they merit admir- ation ; and that which merits admiration we call grand. In the contemplation of uncommon ex- cellence, the mind feels a noble enthusiasm, which disposes it to the imitation of what it admires. 496 ON THE INTELLECTUAL POWERS. [essay vm. When we contemplate the character of Cato — his greatness of soul, his superiority to pleasure, to toil, and to danger ; his ar- dent zeal for the liberty of his country ; when we see him standing unmoved in mis- fortunes, the last pillar of the liberty of Rome, and falling nobly in his country's ruin — who would not wish to be Cato rather than Csesar in all his triumph ? [730] Such a spectacle of a great soul strug- gling with misfortune, Seneca thought not unworthy of the attention of Jupiter him- self, " Ecce spectaculum Deo dignum, ad quod respiciat Jupiter suo operi intentus, vir fortis cum mala fortuna compositus." As the Deity is, of all objects of thought, the most grand, the descriptions given in holy writ of his attributes and works, even when clothed in simple expression, are acknowledged to be sublime. The expres- sion of Moses, " And God said, Let there be light, and there was light,"* .has not escaped the notice of Longinus, a Heathen critic, as an example of the sublime. What we call sublime in description, or in speech of any kind, is a proper expres- sion of the admiration and enthusiasm which the subject produces in the mind of the speaker. If this admiration and enthu- siasm appears to be just, it carries the hearer along with it involuntarily, and by a kind of violence rather than by cool con- viction : for no passions are so infectious as those which hold of enthusiasm. But, on the other hand, if the passion of the speaker appears to be in no degree jus- tified by the subject or the occasion, it pro- duces in the judicious hearer no other emo- tion but ridicule and contempt. The true sublime cannot be produced solely by art in the composition ; it must take its rise from grandeur in the subject, and a corresponding emotion raised in the mind of the speaker. A proper exhibition of these, though it should be artless, is irresistible, like fire thrown into the midst of combustible matter. [731] When we contemplate the earth, the sea, the planetary system, the universe, these are vast objects ; it requires a stretch of imagination to grasp them in our minds. But they appear truly grand, and merit the highest admiration, when we consider them as the work of God, who, in the simple style of scripture, stretched out the heavens, and laid the foundation of the earth ; or, in the poetical language of Milton — " In his hand He took the golden compasses, prepar'd In God's eternal store, to circumscribe This universe and all created things. One foot he centr'd, and the other turn'd Bound thro' the vast profundity obscure ; * Better translated—" Be there light, and light tbere was " — H. And said, Thus far extend, thus far thy bounds This be thy just circumference, O world." When we contemplate the world of Epi- curus, and conceive the universe to be a fortuitous jumble of atoms, there is nothing grand in this idea. The clashing of atoms by blind chance has nothing in it fit to raise our conceptions, or to elevate the mind. But the regular structure of a vast system of beings, produced by creating power, and governed by the best laws which perfect wisdom and goodness could contrive, is a spectacle which elevates the understanding, and fills the soul With devout admiration. A great work is a work of great power, great wisdom, and great goodness, well con- trived for some important end. But power, wisdom, and goodness, are properly the at- tributes of mind only. They are ascribed to the work figuratively, but are really inherent in the author : and by the same figure, the grandeur is ascribed to the work, but is properly inherent in the mind that made it. Some figures of speech are so natural and so common in all languages, that we are led to think them literal and proper expressions. Thus an action is called brave, virtuous, generous ; but it is evident, that valour, virtue, generosity, are the attributes of per- sons only, and not of actions. In the action considered abstractly, there is neither val- our, nor virtue, nor generosity. The same action done from a different motive may deserve none of those epithets. [732] The change in this case is not in the action, but in the agent; yet, in all languages, generosity and other moral qualities are ascribed to actions. By a figure, we assign to the effect a quality which is inherent only in the cause. By the same figure, we ascribe to a work that grandeur which properly is inherent in the mind of the author. When we consider the " Iliad" as the work of the poet, its sublimity was really in the mind of Homer. He conceived great characters, great actions, and great events, in a manner suitable to their nature, and with those emotions which they are naturally fitted to produce ; and he conveys his conceptions and his emotions by the most proper signs. The grandeur of his thoughts is reflected to our eye by his work, and, therefore, it is justly called a grand work. When we consider the things presented to our mind in the " Iliad" without regard to the poet, the grandeur is properly in Hector and Achilles, and the other great personages, human and divine, brought upon the stage. Next to the Deity and his works, we ad- mire great talents and heroic virtue in men, whether represented in history or in fiction. The virtues of Cato, Aristides, Socrates, [730-732] OF UKANDIiUll. 497 Marcus Aurelius, are truly grand. Extra- ordinary talents and genius, whether in poets, orators, philosophers, or lawgivers, are objects of admiration, and therefore grand. We find writers of taste seized with a kind of enthusiasm in the description of such personages. What a grand idea does Virgil give of the power of eloquence, when he compares the tempest of the sea, suddenly calmed by the command of Neptune, to a furious sedition in a great city, quelled at once by a man of authority and eloquence. [733] " Sic ait, ac dicto citius tumida aequora placat : Ac veluti magno in populo, si forte coorta est Seditio, ssnvitque animis ignobile vulgus ; Jamque faces et saxa volant, furor arma ministrat ; Turn pierate gravem, et meritis, si forte virnm quem Compexere, silent, arrectisque auribus adstant. Hie regit dictis animos, et pectora mulcet. Sic cunctus pelagi cecidit fragor." The wonderful genius of Sir Isaac New- ton, and his sagacity in discovering the laws of Nature, is admirably expressed in that short but sublime epitaph by Pope : — " Nature and Nature's laws lay hid in night; God said, Let Newton be — and all was light." Hitherto we have found grandeur only in qualities of mind ; but, it may be asked, Is there no real grandeur in material objects ? It will, perhaps, appear extravagant to deny that there is ; yet it deserves to be considered, whether all the grandeur we ascribe to objects of sense be not derived from something intellectual, of which they are the effects or signs, or to which they bear some relation or analogy. Besides the relations of effect and cause, of sign and thing signified, there are innu- merable similitudes and analogies between things of very different nature, which lead us to connect them in our imagination, and to ascribe to the one what properly belongs to the other. Every metaphor in language is an instance of this ; and it must be remembered, that a very great part of language, which we now account proper, was originally metaphorical ; for the metaphorical meaning becomes the proper, as soon as it becomes the most usual ; much more, when that which was at first the proper meaning falls into disuse. [734] The poverty of language, no doubt, con- tributes in part to the use of metaphor ; and, therefore, we find the most barren and uncultivated languages the most metaphori- cal. But the most copious language may be called barren, compared with the fertility of human conceptions, and can never, with- out the use of figures, keep pace with the variety of their delicate modifications. But another cause of the use of metaphor is, that we find pleasure in discovering rela- tions, similitudes, analogies, and even con- trasts, that are not obvious to every eye. [733-735"! All figurative speech presents something of this kind ; and the beauty of poetical lan- guage seems to be derived in a great mea- sure from this source. Of all figurative language, that is the most common, the most natural, and the most agreeable, which either gives a body, if we may so 'speak, to things intellectual, and clothes them with visible qualities; orwhich, on the other hand, gives intellectual qualities to the objects of sense. To beings of more exalted faculties, intel- lectual objects may, perhaps, appear to most advantage in their naked simplicity. But we can hardly conceive them but by means of some analogy they bear to the objects of sense. The names we give them are almost all metaphorical or analogical. Thus, the names of grand and sublime, as well as their opposites, mean and low, are evidently borrowed from the dimensions of body ; yet, it must be acknowledged, that many things are truly grand and sublime, to which we cannot ascribe the dimensions of height and extension. Some analogy there is, without doubt, be- tween greatness of dimension, which is an object of external sense, and that grandeur which is an object of taste. On account of this analogy, the last borrows its name from the first ; and, the name being common, leads us to conceive that there is something common in the nature of the things. [735] But we shall find many qualities of mind, denoted by names taken from some quality of body to which they have some analogy, without anything common in their nature. Sweetness and austerity, simplicity and duplicity, rectitude and crookedness, are names common to certain qualities of mind, and to qualities of body to which they have some analogy ; yet he would err greatly who ascribed to a body that sweetness or that simplicity which are the qualities of mind. In like manner, greatness and meanness are names common to qualities perceived by the external sense, and to qualities perceived by taste ; yet he may be in an error, who ascribes to the objects of sense that greatness or that meanness which is only an object of taste. As intellectual objects are made more level to our apprehension by giving them a visible form ; so the objects of sense are dignified and made more august, by ascrib- ing to them intellectual qualities which have some analogy to those they really possess. The sea rages, the sky lowers, the meadows smile, the rivulets murmur, the breezes whisper, the soil is grateful or ungrateful — such expressions are so familiar in common language, that they are scarcely accounted poetical or figurative ; but they give a kind of dignity to inanimate objects, and make our conception of them more agreeable. 2 K 498 ON THE INTELLECTUAL POWERS. [ HSSAY \ III, When we consider matter as an inert, extended, divisible, and movable substance, there seems to be nothing in these qualities which we can call grand ; and when we ascribe grandeur to any portion of matter, however modified, may it not borrow this quality from something intellectual, of which it is the effect, or sign, or instrument, or to which it bears some analogy ? or, perhaps, because it produces in the mind an emotion that has some resemblance to that admira- tion which truly grand objects raise -' [736] A very elegant writer on the sublime and beautiful,* makes everything grand or sub- lime that is terrible. Might he not be led to this by the similarity between dread and admiration ? Both are grave and solemn passions ; both make a strong impression upon the mind ; and bpth are very infec- tious. But they differ specifically, in this respect, that admiration supposes some un- common excellence in its object, which dread does not. We may admire what we see no reason to dread ; and we may dread what we do not admire. In dread, there is nothing of that enthusiasm which naturally accompanies admiration, and is a chief in- gredient of the emotion raised by what is truly grand or sublime. Upon the whole, I humbly apprehend that true grandeur is such a degree of ex- cellence as is fit to raise an enthusiastical admiration ; that this grandeur is found, originally and properly, in qualities of mind ; that it is discerned, in objects of sense, only by reflection, as the light we perceive in the moon and planets is truly the light of the sun ; and that those who look for grandeur in mere matter, seek the living among the dead. If this be a mistake, it ought, at least, to be granted, that the grandeur which we perceive in -qualities of mind, ought to have a different name from that which belongs properly to the objects of sense, as they are very different in their nature, and produce very different emotions in the mind of the spectator. [737] CHAPTER IV. OF J3PAUTY. Beauty is found in things so various and so very different in nature, that it is difficult to say wherein it consists, or what there can be common to all the objects in which it is. found. Of the objects of sense, we fiud beauty in colour, in sound, in form, in motion. There are beauties of speech, and beauties of thought ; beauties in the arts, and in the * BuTk? H. sciences ; beauties in actions, in affections, and in characters. In things so different and bo unlike is there any quality, the same in all, which we may call by the name of beauty ? What, can it be that is common to the thought of a mind and the form of a piece of matter, to an abstract theorem and a stroke of wit ? I am indeed unable to conceive any qua- lity in all the different things that are called beautiful, that is the same in them all. There seems to be no identity, nor even similarity, between the beauty of a theorem and the beauty of a piece of music, though both may be beautiful. The kinds of beauty seem to be as various as the objects to which it is ascribed. But why should things so different be called by the same name ? This cannot be without a reason. If there be nothing com- mon in the things themselves, they must have some common relation to us, or to something else, which leads us to give them the,same name. [738] All the objects we call beautiful agree in two things, which seem to concur in our sense of beauty. First, When they are perceived, or even imagined, they produce a certain agreeable emotion or feeling in the mind; and, secondly, This agreeable emotion is accompanied with an opinion or belief of their having some perfection or excellence belonging to them. Whether the pleasure we feel in contem- plating beautiful objects may have any ne- cessary connection with the belief of their excellence, or whether that pleasure be con- joined with this belief, by the good pleasure only of our Maker, I will not determine. The reader may see Dr Price's sentiments upon this subject, which merit considera- tion, in the second chapter of his " Review of the Questions concerning Morals." Though we may be able to conceive these two ingredients of our sense of beauty dis- joined, this affords no evidence that they have no necessary connection. It has in- deed been maintained, that whatever we can conceive, is possible ; but I endeavoured, in treating of conception, to shew, that this opinion, though very common, is a mistake. There may be, and probably are, many necessary connections of things in nature, which we are too dim-sighted to discover. The emotion produced by beautiful ob- jects is gay and pleasant. It sweetens and humanises the temper, is friendly to every benevolent affection, and tends to allay sullen and angry passions. It enlivens the mind, and disposes it to other agreeable emotions, such as those of love, hope, and joy. It gives a value to the object, ab- stracted from its utility. In things that may be possessed as pro- perty, beauty greatly enhances the price, r: 36-7381 ri'AP iv.] OF JiUAUTY. 4!)9 A. beautiful dog or horse, a beautiful coach 01- house, a beautiful picture or prospect, is valued by its owner and by others, not only for its utility, but for its beauty. [739] If the beautiful object be a person, his company and conversation are, on that ac- count, the more agreeable, and we are dis- posed to love and esteem him. Even in u perfect stranger, it is a powerful recom- mendation, and disposes us to favour and think well of him, if of our own sex, and still more if of the other. " There is nothing," says Mr Addison, " that makes its way more directly to the soul than beauty, which immediately diffuses a secret satisfaction and complacence through the imagination, and gives a finishing to anything that is great and uncommon. The very first discovery of it strikes the mind with an inward joy, and spreads a cheerfulness and delight through all its faculties." As we ascribe beauty, not only to per- sons, but to inanimate things, we give the name of love or liking to the emotion, which beauty, in both these kinds of objects, produces. It is evident, however, that liking to a person is a very different affec- tion of mind from liking to an inanimate thing. The first always implies benevo- lence ; but what is inanimate cannot be the object of benevolence The two affections, however different, have a resemblance in some respects ; and, on account of that resemblance, have the same name. And perhaps beauty, in these two different kinds of objects, though it has one name, may be as different in its nature as the emotions which it produces in us. Besides the agreeable emotion which beautiful objects produce in the mind of the spectator, they produce also an opinion or judgment of some perfection or excel- lence in the object. This I take to be a second ingredient in our sense of beauty, though it seems not to be admitted by modern philosophers. [740] The ingenious Dr Hutcheson, who per- ceived some of the defects of Mr Locke's system, and made very important improve- ments upon it, seems to have been carried away by it, in his notion of beauty. In his " Inquiry concerning Beauty,'* § 1, "Let it be observed," says he, "that in the following papers, the word beauty is taken for the idea raised in us, and the sense of beauty for our power of receiving that idea." And again — "Only let it be observed, that, by absolute or original beauty, is not under- stood any quality supposed to be in the object which should, of itself, be beautiful, without relation to any mind which per- ceives it : for beauty, like other names of sensible ideas, properly denotes the per- ception of some mind ; so cold, hot, sweet, [?:?!) -7 11] bitter, denote the sensations in our minds, to which, perhaps, there is no resemblance in the objects which excite these ideas in us ; however, we generally imagine other- wise. Were there no mind, with a sense of beauty, to contemplate objects, I see not how they could be called beautiful." There is no doubt an analogy between the external senses of touch and taste, ami the internal sense of beauty. This analogy led Dr Hutcheson, and other modern phi- losophers, to apply to beauty what Des Cartes and Locke had taught concerning the secondary qualities perceived by the external senses. Mr Locke's doctrine concerning the se- condary qualities of body, is not so much an error in judgment as an abuse of words. He distinguished very properly between the sensations we have of heat and cold, and that quality or structure in the body which is adapted by Nature to produce those sensations in us. He observed very justly, that there can be no similitude be- tween one of these and the other. They have the relation of an effect to its cause, but no similitude. This was a very just and proper correction of the doctrine of the Peripatetics, who taught, that all our sens- ations are the very form and image of the quality in the object by which they are produced. [741] What remained to be determined was, whether the words, heat and cold,- in com- mon language, signify the sensations we feel, or the qualities of the object which are the cause of these sensations- Mr Locke made heat and cold to signify only the sensations we feel, and not the qualities which are the cause of them. And in this, 1 apprehend, lay his mistake. For it is evident, from the use of language, that hot and cold, sweet and bitter, are attributes of external objects, and not of the person who perceives them. Hence, it appears a mon- strous paradox to say, there is no heat in the fire, no sweetness in sugar ; but, when explained according to Mr Locke's meaning, it is only, like most other paradoxes, an abuse of words.* The sense of beauty may be analysed in a manner very similar to the, sense of sweet- ness. It is an agreeable feeling or emotion, accompanied with an opinion or judgment of some excellence in the object, which is fitted by Nature to produce that feeling. The feeling is, no doubt, in the mind, and so also is the judgment we form of the object: but this judgment, like all others, must be true or false. If it be atrue judg- ment, there is some real excellence in the object. And the use of all languages shews that the name of beauty belongs to this ex- * See above, p. 205, li. note *.— H Tfil] IV.] OF BEAUTY. 507 and the exactest shape, without anything of the mind expressed in the face, is insipid and unmoving. The finest eyes in the world, with an excess of malice or rage in them, will grow shocking. The passions can give beauty without the assistance of colour or form, and take it away where these have united most strongly to give it ; and therefore this part of beauty is greatly superior to the other two. [762] The last and noblest part of beauty is grace, which the author thinks undefin- able. Nothing causes love so generally and ir- resistibly as grace. Therefore, in the my- thology of the Greeks and Romans, the Graces were the constant attendants of Venus the goddess of love. Grace is like the cestus of the same goddess, which was supposed to comprehend everything that was winning and engaging, and to create love, by a secret and inexplicable force, like that of some magical charm. There are two kinds of grace — the majes- tic and- the familiar ; the first more com- manding, the last more delightful and en- gaging. The Grecian painters and sculp- tors used to express the formermost strongly in the looks and attitudes of their Miner- vas, and the latter in those of Venus. This distinction is marked in the description of the personages of Virtue and Pleasure in the ancient fable of the Choice of Hercules. *' Graceful, bui each with different grace they move, This striking sacred awe, that softer winning love." In the persons of Adam and Eve in Pa- radise, Milton has made the same distinc- tion — " For contemplation he, and valour formed, For softness she, and sweet attractive grace." [7631 Though grace be so difficult to be defined, there are two things that hold universally with relation to it. First, There is no grace without motion ; some genteel or pleasing motion, either of the whole body or of some limb, or at least some feature. Hence, in the face, grace appears only on those features that are movable, and change with the various emotions and sentiments of the mind, such as the eyes and eye- brows, the mouth and parts adjacent. When Venus appeared to her son ^Eneas in disguise, and, after some conversation with him, retired, it was by the grace of her motion in retiring that he discovered her be to truly a goddess. " Dixit, et avertens rosea cervice refulsit, Ambrosisque com» divinum vertice odorem Spiravere j pedes vestis defluxit ad imos ; Et vera incessu patuit dea. Illc, ubi matrcm Apuovit," &c. A second observation is, That there can be no grace with impropriety, or that no- thing can be graceful that is not adapted to the character and situation of the person. From these observations, which appear [726-765.] to me to lie just, wc may, I think, conclude, that grace, as far as 'it is visil'le, consists of those motions, either of the whole body, or of a part or feature, which express the mo&t perfect propriety of conduct and sentiment in an amiable character. Those motions must be different in dif- ferent characters; they must vary with every variation of emotion and sentiment ; they may express either dignity or respect, confidence or reserve, love or just resent- ment, esteem or indignation, zeal or indif- ference. Every passion, sentiment, or emo- tion, that in its "nature and degree is just and proper, and corresponds perfectly with the character of the person, and with the oc- casion, is what may we call the soul of grace. The body or visible part consists of those emotions and features which give the true and unaffected expression of this soul. [7G4 ] Thus, I think, all the ingredients of human beauty, as they are enumerated and described by this ingenious author, termi- nate in expression : they either express some perfection of the body, as a part of the man, and an instrument of the mind, or some amiable quality or attribute of the mind itself. It cannot, indeed, be denied, that the expression of a fine countenance may l.e unnaturally disjoined from the amiable qua- lities which it naturally expresses : but we presume the contrary till we have clear evi- dence ; and even then we pay homage to the expression, as we do to the throne when it happens to be unworthily filled. Whether what I have offered to shew, that all the beauty of the objects of sense is borrowed, and derived from the beauties of mind which it expresses or s ggests to the imagination, be well-founded or not, 1 hope this terrestrial Venus will not be deemed less worthy of the homage which has always been paid to her, by being con- ceived more nearly allied to the celestial than she has commonly been represented. To make an end of this subject, taste seems to be progressive as man is. Child- ren, when refreshed by sleep, and at ease from pain and hunger, are disposed to at- tend to the objects about them ; they are pleased with brilliant colours, gaudy orna- ments, regular forms, cheerful counte- nances, noisy mirth and glee. Such is the taste of childhood, which we must con- clude to be given for wise purposes. A great part of the happiness of that period of life is derived from it ; and, therefore, it ought to be indulged. It leads them to attend to objects which they may afterwards find worthy of their attention. It puts them upon exerting their infant faculties of body and mind, which, by such exertions, are daily strengthened and improved. [765] As they advance iiv years and in under- 508 ON THE INTELLECTUAL POWERS. [essay viii.* standing, other beauties attract their atten- tion, which, by their novelty or superiority, throw a shade upon those they formerly ad- mired. They delight in feats of agility, strength, and art ; they love those that ex- cel in them, and strive to equal them. In the tales and fables they hear, they begin to discern beauties of mind. Some characters and actions appear lovely, others give dis- gust. The intellectual and moral powers begin to open, and, if cherished by favour- able circumstances, advance gradually in strength, till they arrive at that degree of perfection to which human nature, in its present state, is limited. In our progress from infancy to maturity, our faculties open in a regular order ap- pointed by Nature ; the meanest first, those ,f more dignity in succession, until the mo- ral and rational powers finish the man. Every faculty furnishes new notions, brings new beauties into view, and enlarges the province of taste ; so that we may say, there is a taste of childhood, a taste of youth, and a manly taste. Each is beau- tiful in its season ; but not so much so, when carried beyond its season. Not that the man ought to dislike the things that please the child or the youth, but to put less value upon them, compared with other beauties, with which he ought to be ac- quainted. Our moral and rational powers justly claim dominion over the whole man. Even taste is not exempted from their authority ; it must be subject to that authority in every case wherein we pretend to reason or dispute about matters of taste ; it is the voice of reason that our love or our admiration ought to be proportioned to the merit of the object. When it is not grounded on real worth, it must be the effect of constitution, or of some habit, or casual association. A fond mother may see a beauty in her dar- ling child, or a fond author in his work, to which the rest of the world are blind. In such cases, the affection is pre-engaged, and, as it were, bribes the judgment, to make the object worthy of that affection. For the mind cannot be easy in putting a value up ^n an object beyond what it con- ceives to be due. When affection is not carried away by some natural or acquired bias, it naturally is and ought to be led by the judgment. [766] As, in the division which I have followed of our intellectual powers, I mentioned Moral Perception and Consciousness, the reader -may expect that some reason should be given, why they are not treated of in this place. As to Consciousness, what I think neces- sary to be said upon it has been already said, Essay vi., chap. 5. As to the faculty of moral perception, it is indeed a most im- portant part of human understanding, and well worthy of the most attentive considera- tion, since without it we could have no con- ception of right and wrong, of duty and moral obligation, and since the first princi- ples of morals, upon which all moral rea- soning must be grounded, are its immediate dictates ; but, as it is an active as well as an intellectual power, and has an immediate relation to the other active powers of the mind, I apprehend that it is proper to defer tho consideration of it till these be explained [766]