The original of tiiis 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/cletails/cu31924097313294 In compliance with current copyright law, Cornell University Library produced this replacement volume on paper that meets the ANSI Standard Z39.48-1992 to replace the irreparably deteriorated original. 2003 In compliance with current copyright law, Cornell University Library produced this replacement volume on paper that meets the ANSI Standard Z39.48-1992 to replace the irreparably deteriorated original. 2003 CORNELL UNIVERSITY LIBRARY GIF:r OF R. M, Ogden HUME: THE EELATION OF THE TEEATISE OP HTIMAlir NATUEE— BOOK I TO THE IISTQUIEY COISTCEENING HUMAN UNDEESTANDING W. B. ELKIN, Ph.D. ACTING ASSISTANT PBOPESSOB OP THEORY AND PBACTICE OF TEACHING TW TUT. nNTVERSTTT OP MTRSOnRI. ITHACA, N, Y. 1904 IV PREFACE. Dr. N. E. Truman, on whom fell the laborious task of reading the proofs and verifying the references; and to The Sage School of Philosophy, which spared neither trouble nor expense to procure any books of reference that were thought helpful for the work. W. B. E. COLtTMBIA, Mo. May 31, 1904. CONTENTS. OHAPTEE I. Inteoduotion. Page. § 1. Preliminary Eemarks 1 § 2. Aim 4 § 3. The General Relation of the Treatise and In- quiry to Hume's other Philosophical Works. . 6 § 4. The General Eelation of the Treatise and In- quiry to each other 10 I. With regard to Porm 10 II. With regard to Content 16 § 5. Mode of Procedure 23 CHAPTER II. Hume's Aim, Subject-MIatter, and Method. § 6. Hume's Aim 24 § 7. Hume's Subject-Matter 41 § 8. Hume's Method 45 CHAPTER in. Peeceptions: theie Nature, and Cause. § 9. The E"ature, and Classification of Perceptions. . 50 §10. The Cause of Perceptions 59 I. Epistemological 60 H. Physiological 63 §11. Conclusion 69 T \ vi humb's treatise and inquiry. CHAPTEE IV. AssoouTioN OF Ideas, and Result — Complex Ideas. 'Pi.as. §12. Association of Ideas » • • • '^1 §13. Complex Ideas 77 I. Philosophical Eelations 77 II. General or Abstract Ideas 83 §14. Conclusion * ^^ CHAPTER V. Space and Time. §15. The Idea of Infinite Divisibility. . . : 89 §16. Tie Idea of Space 91 §17. The Idea of Time 95 §18. The Treatment of Space and Time in the Inquiry 95 §19. Conclusion 98 CHAPTER VI. Theory op Knowledge. §20. The Faculties of Mind 102 V • §21. Intiiitive Knowledge : 106 i/^ §22. Demonstrative Ejiowledge — Mathematics Ill I. The Epistemological Exposition 113 II. The Logical Exposition 117 v^ m. The Psychological Exposition 123 v^ IV. Conclusion 124 i^ §23. The Treatment of Mathematics in the Appendix 125 §24 The Treatment of Mathematics in the Inquiry. . 126 §25. The Treatment of Mathematics in Htmie's other Philosophical Writings 132 826. Conclusion 134 CONTENTS. Vll CHAPTER Vn. The Idea of Cause and Effect. Page. §27. Causation the basis of all Eeasoning Concern- ing Matters of Fact 140 §28. Examination of the Idea of Cause and Effect. . . 142 I. The General Question of Causation 144 H. The Particular Question of Causation. . . . iJL46^ m. The Idea of Necessary Connection V-J^ rV. Conclusion 155 §29. Some Misconceptions of Hume's Critics 157 §30. Conclusion 168 CHAPTEE Vni. Belief. §31. Belief of Impressions 172 §32. Belief of Ideas. 174 I. The Exposition of the Treatise 174 II.- The Exposition of the Appendix 175 m. The Exposition of the Inquiry 180 §33. The Cause of Belief 190 §34 Conclusion 192 CHAPTEE IX. Peobabilitt, Necessity, aitd the Eeason of Animals. §35. Probabilily .- 195 I. The Account in the Treatise 196 H. The Account in the Inquiry 198 ni. Conclusion 199 §36. Liberty and Necessity 201 §37. The Eeason of Animals 210 viii hdme's treatise and inquiet. OHAPTEE X, !Mateeial Substance and External Existence. Pace, §38. The Idea of Material Substance 216 §39. The Idea of External Existence 220 I. The Vulgar Hypothesis 220 n. The Philosophical Hypothesis 224 §40. Conclusion 228 CHAPTEE XI. Spiritual Substance, Self, and Personal Identity. §41. The Idea of Spiritual Substance 235 §42. The Idea of SeH 237 §43. The Idea of Personal Identity 239 §44. The Eelation of the Treatise to the Inquiry on the Doctrines of Self and Personal Identity. . 242 §45. Conclusion 356 OHAPTEE XII. Miracles, a Particular Providence, and a Future Life. §46. Miracles 269 §47. A Particular Providence 266 §48. A Future Life. 275 CHAPTEE XHL - OONCLITSIQN. t §49. Summary 293 •i §50L_^hinie's Philosophical System 295 I.~^EpiStenrology 296 ■J H. Metaphysics 302 »/lII. The Philosophy of Eeligion 306 rV. Conclusion , 307 CONTENTS. IX APPENDIX A. PAGE. Outline of the Eelation of the Treatise to the Inquiet 311 APPENDIX B. Bibliography. I. Editions and Translations of the Treatise and Inquiry 315 n. Books 316 m. Periodicals 325 CHAPTER I. INTEODTJOTION. § 1. Prelimvnary Remarks.— HhQ history of Eng- lish empirical philosophy is sometimes Ukened to a drama in five acts. In the first act, a system of em- piricism is inaugtirated by Bacon; in the second and third, the dialectic movement is gradually unfolded by Hobhes and Locke; in the fourth, the usual compli- cations arise through the criticisms and transforma- tions of Berkeley; finally, in the fifth, the scene closes with the annihilating catastrophe of Hume.^ But as Hume marked the melancholy close of the era of sensationalism, he heralded the inspiring dawn of a brighter epoch, the era of idealism, and at the same time laid the foundation for a synthesis of the two, in the more scientific movement of the present age. Reid in Scotland and Kant in Germany were awakened, almost simultaneously, from their dogmatic slumbers, by the subtle and irresistible dialectic of the great skeptic. British and German philosophy, how- ever, when drifting peacefully toward a euthanasia, far from being overwhelmed by the storm of Hume's criticism, were only instigated thereby to make a new tack in the never-ending pursuit of speculative truth. With felicity no less than impressiveness. Sir "William Hamilton, in his introductory lecture in 1836, de- clared: "The man who gave the whole philosophy of ' Of. Grimm, Zur Oeschichte des Erhenntnisprdblema von Bacon eu Hume, Vofwort. 1 1 2 Hume's treatise and inquiht. Europe a new impulse and direction, and to whom, mediately or immediately, must be referred every sub- sequent advance in philosophical speculation, was our countryman— David Hume. . . . The skepticism of Hume, like an electric spark, sent life through the paralyzed opinions; philosophy awoke to renovated vigor, and its problems were agaia to be considered in other aspects, and subjected to a more searching analysis. ' ' It matters little in what manner the position of "the last great English philosopher" be designated in the history of speculative thought, for his system is so unique, and so significant that it will .always awaken the most profound reflection, as well as merit the most candid examination. The study of Hume's works, however, is unusually perplexing, and the true significance of his philosophy of human nature ex- tremely difficult accurately to determine, partly, be- cause of the different phases of thought, obscurities, ambiguities, and even inconsistencies that appear in his writings, but chiefly, because of the twofold ex- position of his system. Before a just estimation of his philosophy can be arrived at, the more important relations subsisting between his philosophical writings must be ascertained. It is, therefore, a question of much interest what the relations of his chief works are to one another. Moreover, this question is also one of much importance. For although Hume's in- fluence is not perhaps so great now as when James Hutchison Stirling wrote :^ "Hume is our Politics, Hume is our Trade, Hume is our Philosophy, Hume is our Religion, — it wants little but that Hume were even The Secret of Hegel, p. bcxiii. INTEODUCTION. O our Taste," his once strikmg position in philosophical and political thought is stiU justly prominent. "The Treatise of Human Nature and the Critic of Pure Reason," remarked his most relentless critic/ "taken together, form the real bridge between the old world of philosophy and the new. They are the essential 'Propaedeutic,' without which no one is a qualified student of modem philosophy. ' ' Hume's great philosophical work is A Treatise of Human Nature. It consists of three books: I, "Of the Understanding"; II, "Of the Passions"; III, "Of MoTah" ;— intellect, feeling, and viill. The first two volumes were published in 1739, and the third in 1740. It seems, however, that the book was writ- ten as early as 1736, when Hume was only twenty- .five years old.^ True, in accordance with one of the author's distinctive characteristics, it was contin- ually revised, up to the very time of publication.' Yet the changes which were made appear to have dealt with form more than with content ; and so far as they had reference to content, they were made rather in the way of omission, than in the way of development.* But the Treatise of Human Nature awakened no in- terest, and received almost no notice; it "fell dead- born from the press," — to use the expressive words of the author. Nevertheless, Hume, thinking that he ' Hume's Philosophical Works, I. Green's " Introduction," p. 3. — ^The references throughout are to the Green and Grose edi- tion; I, 1890 J II, 1882; III and IV, 1889. Since I, contains the Treatise and IV, the Inquiry, in explicit references to these works the volume number is not giyen. ' Of. Burton, Life mid Correspondence of David Eume, I, pp. 98, 337. " Ibid., I, pp. 62, 63. « Hid., pp. 63, 64. i htjme's treatise and inqtjiry. had made a mistake in publishing too early, stiU be- lieved that his system of philosophy was of permanent value.' Hence, he revised the Treatise of Human Nature, and published it in much briefer, and more popular form. The abbreviated work appeared as follows : Philosophical Essays concerning Human Un- derstanding, 1748; An Inquiry concerning the Prin- ciples of Morals, 1751 ; A Dissertation on the Passions, 1757. It is only with the first book of each group that I propose to deal in the present volume. These books will be designated respectively, for the sake of convenience and in accordance with common usage, the Treatise, and the Inquiry. Eeference, of course, will be made, from time to time, to Hume's other philosophical writings, for the purpose of throwing additional light upon the subject, or in order to obtain a more comprehensive view of the matter under dis- cussion. § 2. Aim. — There is a general impression that the position which Hume adopted in the Inquiry is not identical with that which he had previously as- sumed in the Treatise, and consequently, that the philosophical principles of the later work are not exactly the same as those of the earlier. It is sometimes said that the Inquiry represents the posi- tion of the empiricist, or positivist, while the Treatise represents the position of the skeptic; — as was re- marked recently by one of the most brilliant philo- sophical writers, of our time:' "The Treatise is the close of sensationalist philosophy, the Inquiry the be- ginning of com m on sense philosophy." Hence, it is 1 Hume, My Own Life. ^Sehurman, The Philosophical Revievo, Vol. VII, p. 10, n. INTBODUCTION. 5 inferred that tlie later work, not being so negative as the earlier, represents an important change as having occurred in the author's thought when his mind be- came more mature.^ On the other hand, some writers assert that the position, or standpoint of both books is essentially the same. " But then, regarding the ex- act nature of that position there are again differences of opinion; Huxley, ° for example, insisting that it is mainly positive, and Green* maintaining that it is chiefly negative. If we appeal to the testimony of the author himself, this confusion is by no means re- moved. For in the advertisement to the second vol- ume of the posthumous and authoritative edition of his Essays and Treatises on Several Subjects — a vol- ume containing the Inquiry, — not only does Hume complain that "several writers, who have honored the author's philosophy with answers, have taken care to direct all their batteries against the juvenile work, which the author never ackiiowledged," but he con- cludes as follows:^ "Henceforth, the author desires, that the following pieces may alone be regarded as containing his philosophical sentiments and prin- ciples." Yet on another occasion, in a letter to Gil- 1 Cf. Burton, Life, I, pp. 120, 273, 274; Erdmann, History of Philosophy, II, p. 128; Palckenberg, Oesch, d. neueren Phil., second ed., p. 185, n. 2; Hyslop, Hume's Treatise on Morals, p. 17; Hunt, Contemporary Review, Vol. XI, p. 77. 2 Of. Green, "Introduction to Hume"; Huxley, Hume, pp. 11, 45; Webb, Veil of Isis, p. 71; McCosh, Hist, of Soottish Phil., p. 123; Jahn, D. H, Oausalitdtstheorie, p. 6. 3 Hume, pp. 51, 60. * Hume's Philosophical Works, Preface to Vol. I, and General Introd. 5 Ibid., Ill, p. 38. 6 Hume's treatise and inquirt. bert Elliot, he says:* "I believe the Philosophical Essays [the Inquiry] contain every thing of con- sequence relating to the understanding, which you would meet with in the Treatise; and I give you my advice against reading the latter. By shortening and simplifying the questions, I really render them much more complete. Addo dum minuo. The philo- sophical principles are the same in bothj but I was carried away by the heat of youth and invention to publish too precipitately." To clear up this ob- scurity on the question regarding Hume's exact posi- tion in his two chief philosophical works is the aim of the present investigation. § 3. The General Relation of the Treatise and In- quiry to Hume's other Philosophical Writings. — Be- fore entering upon the work in detail, it may be well to indicate, in a general way, the relation in which these two books stand, (1) to the philosophical writ- ings with which they are connected, and (2) to each other. The first of these topics will be treated in the present section, the second, in the following sec- tion. As has already been said, it is only the first book of each group that falls within the scope of this investigation. But here two questions at once sug- gest themselves: (1) "What are the relations of the different books within each group to one another? and (2) Can the relation of the Treatise to the In- quiry be thoroughly examined without taking account also of the books with which these two are respectively connected? Leaving aside the second question for the moment, we find a partial answer to the first, in the ad- 1 Burton, Life, I, p. 337; of. p. 98. INTRODUCTION. 7 vertisement to Books I and II of the Treatise of Hu- man Nature. "The reader must only observe," says Hume, "that all the subjects I have there planned out to myself, are not treated of in these two volumes. The subjects of the Understanding and Passions make a complete chain of reasoning by themselves; and I was willing to take advantage of this natural division, in order to try the taste of the public. If I have the good fortune to met with success, I shall proceed to the examination of Morals, Politics, and Criticism; which will complete this Treatise of Human Nature. ' ' Here it is seen that Hume regarded Books I and II as forming a connected piece, thus practically con- stituting one book. But the relation of these two volumes to the third is not so close, as the author has already indicated, and as he afterwards specifies more definitely in the advertisement to Book III. "I think it proper to inform the public," he says, "that though this be a third volume of the Treatise of Human Nature, yet it is in some measure independ- ent of the other two, and requires not that the reader should enter into aU the abstract reasonings con- tained in them. ... It must only be observed, that I continue to make use of the terms, impressions and ideas, in the same sense ais formerly." From these quotations we learn that Hume's philosophy, so far as it is presented in the Treatise of Human Nature, falls into two general divisions which are, in large measure, independent of each other, viz., the phi- losophy of the understanding and passions on the one hand, and the philosophy of morals on the other. In the first section of the Inquiry, the author adopts the twofold classification of mental science 8 humb's teeatisb and inquirt. whicli the Latins had inherited from the Greeks, which the scholastics had popularized, and which pre- vailed in occidental philosophy generally, until super- seded by the tripartite division of Kant;— a division which, through the present dominating influence of the biological sciences, is again giving place to the Aristotelian classification. JS3jia6_&tates that moral philosophy or the sci ence of human nature ^ma ylbe jtreated at't^r t wo fiitfpirant manners." abstractly , or concretely.^ And besides making this distinct ion in meth od, he recognizes a corresponding division of su b- '~ject-matter, viz., the "abstruse" or theoretical pM - losophy, a nd the "easy" or prac tical; the former be- 1^ conversant with the understanaing. ana thgH at'ter with the feelJTiM and will. Thus he asserts:" "There arp TTfiqn.-n- n>>Tnrmg t^igtin etlOna I Detwec n the pOWC TS and faculties of the mind ] , such as tho sp b f ^"^p"^^'' will anrl nT1P. 305. 2 P. 550. P. 307. 28 Hume's treatise and inqtjiey. decision is not comprized in the science of man ; and there is none, whicli can be decided with any cer- tainty, before we become acquainted with that sci- ence." If, therefore, we obtain a mastery of the science of man, "we may extend our conquests over all those sciences, which more intimately concern hu- man life, and may afterwards proceed at leisure to discover more fully those, which are the objects of mere curiosity."^ "In pretendiag, therefore," he con- tinues, "to explain the principles of human nature, we in effect propose a complete system of the sciences, built on a foundation almost entirely new, and the only one upon which they can stand with any se- curity." Although Hume here makes extravagant claims for his philosophy, there cannot be any doubt with regard to his meaning. He wiU write a treatise that will include the sciences of "Logic, Morals, Criticism, and Politics"; a treatise that will not only serve as a handmaid to all the other sciences, but that wiU at the same time comprehend "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. ' '^ For he believes he has discovered the "new medium, "° by which truth may be established.* This thought not only implied a brilliant generalization, but also indicated, in a striking manner, that practical turn of mind so char- acteristic of the philosophers of Scotland. In the Inquiry, Hume's aim, on a cursory examina- 1 P. 307. 2 lUd. a Burton, Ufe, I, p. 31. * Gf. Aikins, The Philosophy of Hume, p. 35 ; McCosh, Hist, of Scottish Phil., pp. 153, 154; Petzholtz, Die Hauptpmikte d. H. Brkermtmslehre, p. 8j Falekenberg, Hist, of Modern Phil., p. 221. AIM, SUBJECT-MATTEE, AND METHOD. 29 tion, seems to be similar to tliat of the Treatise of Human Nature.''- In the first section, the author re- gards knowledge as being in the same imperfect con- dition as formerly. The "abstruse philosophers," he says,^ "think it a reproach to aU literature, that philosophy should not yet have fixed, beyond contro- versy, the foundation of morals, reasoning, and crit- icism ; and should for ever talk of truth and falsehood, vice and virtue, beauty and deformity, without being able to determine the source of these distinctions." Hume does not make such large claims, however, on behalf of his philosophy of human nature as he did in the earlier work, probably because of disappoint- ment at the failure of the Treatise to call forth public notice.' As early as 1740, in a letter to Hutcheson, he said:* "I am apt in a cool hour to suspect, in gen- eral, that most of my reasonings wiU be more useful by furnishing hints, and exciting people's curiosity, than as containing any principles that will augment the stock of knowledge, that must pass to future ages." Even in passages of the Treatise, he mani- fested an apprehension that he would not obtain the degree of success he hoped for. He did not expect to make "many proselytes" to his view of belief ;° he did not doubt that his sentiments on necessary connec- tion would be treated by many of his readers as "ex- travagant and ridiculous";* finally, after bewailing "the wretched condition, weakness, and disorder of ' Cf. Pillon, Psydhologie de Hume, p. II. 2 P. 4. 3(7/. Burton, Life, 1, pp. 105, 108; Hume, Eist. of England, VII, p. 359. < Burton, Life,. 1, p. 118. 6 P. 416. 6 Pp. 46l', 468. 30 HTJMe'S treatise and rNQTJIBY. the faculties," together with "the impossibility of amending or correcting" them, he made the doleful confession:^ "This sudden view of my danger [of perishing on the barren rock, on which I am at pres- ent], strikes me with melancholy; and as it is usual for that passion, above all others, to indulge itself; I cannot forbear feeding my despair, with aU those desponding reflections, which the present subject fur- nishes me with in such abundance. ' ' Hume, no doubt, did not mean all these forebodings to be taken lit- erally. Yet, since the reception given the Treatise justified his fears to the full, it is not surprising to find a tone of dejection in the introduction to the Inquiry. "Abstruse thought and profound re- searches," he says," "[nature prohibits], and wiU severely punish, by the pensive melancholy which they introduce, by the endless uncertainty in which they involve you, and by the cold reception which your pretended discoveries shall meet with, when communi- cated." Nevertheless, as before, Hume thinks that the sci- ence of man "has its peculiar merit," and that it will contribute to "the entertainment, instruction, and reformation of mankind."' After distinguishing theoretical philosophy from practical, he states that the theoretical philosophers "think themselves suffi- ciently compensated for the labor of their whole lives, if they can discover some hidden truths, which may contribute to the instruction of posterity."* He as- serts that, by employing the maxim of the priority of iP. 544; of. Burton, Life, I, p. 105. sp. 6. 3 P. 3. «P. 4; of. IV. p. 263. AIM, SUBJECT-MATTER, AND METHOD. 31 impressions to ideas, "we may reasonably hope to remove all disputes, which may arise," concerning the nature and reality of ideas.^ And he maintaias that the science of man wUl facilitate the advancement of aU other sciences ; for theoretical philosophy is sub- servient to practical. The latter without the former, "can never attain a sufficient degree of exactness in its sentiments, precepts, or reasonings"; and a spirit of accuracy carries "every art or profession" nearer its perfection, rendering it "more subservient to the interests of society." Hence, the genius of philos- ophy gradually diffuses itself "throughout the whole society," and bestows "a similar correctness on every art and calling."^ Thus far, although Hume, for the reason already mentioned, is not so sanguine as formerly in his man- ner of expression, there is no difference noticeable be- tween the aim of the Treatise of Human Nature and the aim of the Inquiry. Presently, however, a new aspect of the question emerges. It is objected, in the later work, that "metaphysics^" that is, "abstruse philosophy," is not "properl/ a science," and that "a considerable part of metaphysics" arises either from "the fruitless efforts of human vanity," or from "the craft of popular superstitions."* To this the author answers that for the same reason the study of human nature is the more necessary. "The only method of freeing learning, at once, from these ab- struse questions, is to inquire seriously into the nature of human understanding, and show, from an exact analysis of its powers and capacity, that it is by no means fitted for such remote and abstruse subjects. >P. 17. 2 Pp. 6, 7; cf. p. 24. »P. 8. 32 Hume's treatise and ustqitiey. "We must submit to this fatigue, in order to live at ease ever after : And must cultivate true metaphysics with some care, in order to destroy the false and adulterate,"^ And he concludes the section with the hope that he may be able to "undermine the founda- tions of an abstruse philosophy, which seems to have hitherto served only as a shelter to superstition, and a cover to absurdity and error." Because of the remarks just quoted, and on account of changes in the subject-matter of the Inquiry, many of Hume's interpreters have thought that the aim of the later work is essentially different from that of the earlier. Thus Aikins asserts:* "The investiga- tion of Human Nature was undertaken in the hope that through a knowledge of its principles a founda- tion for all the sciences coulS be laid." — "The In- quiry, on the other hand, was written after the bit- terly disappointing reception given the Treatise had quenched much of Hume's zeal for philosophy and driven him to work in other fields of literature. . . . Now not only was he addressing a popular audience, but he had lost enthusiasm for his subject, and the Enquiry concerning Human Understanding suggests more than a suspicion that Hume's interest in it was more anti-theological than psychological. The intro- duction speaks, not of the foundation to be laid for all the sciences by the study of human nature, but of popular superstitions to be driven from their shelter among the brambles of metaphysics.'" Brede* and some other critics have expressed a similar view on this question. ' P. 9. 2 Phil, of Hume, p. 35. ^Ihid., p. 49. *Der UntersoMed d. Lehren H., pp. 45 flf.j of. Seth, SootUsh Philosophy, p. 69. AIM, SUBJECT-MATTER, AND METHOD. 33 Respecting the change in subject-matter a general explanation was given in the preceding chapter -^ fur- ther reference to the topic wiU be made presently.* It should be observed now, that those writers who profess to perceive a difference in the aim of the two works neglect to note that, ia the concluding section of the Treatise, Hume supplements the statement of his aim given in the general introduction. The aim in the introduction, as previously remarked," is the general aim of the whole work, the Treatise of Euman Nature; that aim. as modified in the last section of Book I is the particular aim of the Treatise, the book with which we are dealing. In order, therefore, to obtain a correct idea of the aim of the Treatise, it is necessary to take account of the concluding section. Here Hume, after stating that the sentiments of curiosity and ambition are "the origin" of his phi- losophy, asserts:* "But even suppose that this curios- ity and ambition should not transport me into specu- lations without the sphere of common life, it would necessarily happen, that from my very weakness I must be led iato such inquiries. It is certain, that superstition is much more bold in its systems and hypotheses than philosophy; . . . Since, therefore, it is almost impossible for the mind of man to rest, like those of beasts, in that narrow circle of objects, which are the subject of daily conversation and action, we ought only to deliberate concerning the choice of our guide, and ought to prefer that which is safest and most agreeable. And in this respect I make bold to recommend philosophy, and shall not scruple to iPp. 16-22. »Pp. 36-^1. 'P. 24. «Pp. 550, 551; of. IV, p. 406. 3 34 Hume's treatise and mQumY. give it the preference to superstition of every kind or denomination." In these sentences, it is true, the author does not explicitly state that one of the ob- jects of the Treatise was to overthrow superstition. Nevertheless, such an object is evidently implied, both here and ia other passages of the book. Thus he says that, "if we are philosophers, it ought only to be upon skeptical principles, and upon an inclination, which we feel to the employing ourselves after that man- ner."^ It may be objected, perhaps, that the aim of the later work still appears to be somewhat different from that of the earlier. For in the Treatise^ Hume re- peatedly repudiates metaphysics, while in the first section of the Inquiry he seems to advocate the pur- suit of this study. "But may we not hope that phi- losophy," he asks,' "if CTiltivated with care, and en- couraged by the attention of the public, may carry its researches stiU farther, and discover, at least in some degree, the secret springs and principles, by which the human mind is actuated in its operations ? " The rejection of a subject of examination, he con- tinues, on the ground that it does not lie "within the compass of human understanding, "is not desirable; nor ought to be embraced too rashly." The differ- ence here pointed out, however, is only apparent. Hume, in the Inquiry,* disavows all truly metaphys- ical investigations as fully as in the Treatise. When he expresses the hope that philosophy may discover, "at least in some degree, the secret springs and prin- ciples, by which the mind is actuated in its opera- iP. 550; of. pp. 308, 309; IV, pp. 27, 28. 2 Pp. 321, 392, 460, » Pp. 11, 12. *0f. pp. 8, 13, 27, 28, 30, 66, 133. AIM, SUBJECT-MATTEB, AND METHOD. 35 tions," lie does not expect to discover the nature of ultimate or metaphysical principles, but only to arrive at an explanation of such principles as "cus- tom," or "the association of ideas." These prin- ciples he occasionally speaks of as ultimate or original qualities of human nature, and he tries — "at least in some degree"— to account for the mode of their oper- ation.^ The fact that Hume, in the introduction to the Treatise, reprobates metaphysics, and yet in the first section of the Inquiry argues at considerable length in defence of metaphysics, is easily explained. He uses the term in two very different senses. There is the true metaphysics, and the false. The former merely means "profound reasonings," or "every kind of argument, which is any way abstruse";" while the latter means rationalistic, or transcendental speculations. Rationalistic speculations Hume uni- versally condemns; but "profound reasonings" he defends in the Treatise as well as in the Inquiry.' Several of the arguments which he adduces in the later work, iu favor of philosophical studies, appeared in the earlier, either in the general introduction, or in the concluding section. For instance, in the intro- duction to the Inquiry he commends the study of "metaphysics" as a means of "safe and harmless pleasures"; but in the conclusion to the Treatise he asserted:* "These sentiments [of curiosity and am- bition] spring up naturally in my present disposition; and should I endeavor to banish them, by attaching 1 Of. I, pp. 321, 330; IV, p. 37. •I, p. 306; IV, p. 6. »0f. I, pp. 306-309; IV, pp. 6-9. *P. 550. 36 Hume's treatise and inquiet. myself to any other business or diversion, I feel I should be a loser in point of pleasure ; and this is the origin of my philosophy." "While it is readily admitted that the references, in the later work, to the overthrow of superstition, are more definite and emphatic than are those iu the earlier ; it must, at the same time, be pointed out that they seem to have been made but incidentally. Hume, in the Inquiry, when still grieving over the sad fate of the Treatise, entered on a special defence of meta- physics, or "profound reasonings." In the course of the discussion it is asserted, as a serious objection to these studies, that "a considerable part of meta- physics" arises either from "the fruitless efforts of human vanity," or from "the craft of popular super- stitions." Whereupon, the author naturally replies that there is then so much the more reason why- "true" metaphysics should be cultivated with care, in order that superstition, or "the false and adulter- ate," may be destroyed. That the defence of meta- physics is fuller and more systematic in the Inquiry than in the Treatise, is doubtless due largely to the unfavorable reception accorded to the earlier work. Besides, as has been remarked, the first section of the Inquiry is an introduction to the thfeeretical part of the science of man, while the corresponding section of the Treatise of Human Nature is an*^ introduction to the science in general; and this, Hume probably thought, did not require any special defence or apology. The aim of the Treatise, therefore, is found upon closer examination to be essentially the same as that of the Inquiry, viz., to explain the nature or char- AIM, SUBJECT-MATTER, AND METHOD, 37 acter of human knowledge, through an investigation of the contents of the individual mind, in order to advance science on the one hand, and to overthrow "superstition" and rationalistic philosophy on the other.^ It is true, the aim is stated in a different manner in the two works ; but for this difference, rea- sons have already been assigned.^ In all probability, however, it will still be objected that the aim of both works can hardly be the same, since the Inquiry contains much new material of a polemical character. The force of the objection dis- appears at once, when one reflects that Hume had already published part of this material in Book II of the Treatise of Human Nature,^ and that he in- tended to publish the remainder— all, or at lesist the larger portion— in Book I, but withdrew it at the last moment, lest it should give "too much offense" as the world was then "disposed."* If it be con- tended further, that the aim of both works is not identical, since much old material is omitted in the Inquiry; the obvious reply is, that these omissions do not necessarily affect Hume's theory of knowledge. Moreover, the essential aim of an abridged work may be exactly the same as that of the complete work. But finally, it wiU no doubt be said that the character and tone of the two books are fundamentlly different, and that the aim must, therefore, be different also. The premises in this case are admitted, but not the con- clusion — except in part, and here is where the ground 1 Cf. Pillon, Psychologie de Hume, p. iii. sPp. 28-31, above. 'Cf. p. 22, above. * Burton, Life, I, pp. 63, 64. 38 Hume's treatise and inqtjiet. for debate really lies. A few words of explanation, however, will make the matter clear. In writing a book, an author may be said to have, in general, two kinds of aims, intrinsic or universal, and extrinsic or individual. The iatriasic aim is the desire of the writer to advance knowledge, or promote truth, happiness, etc., by means of the principles or ideas expressed. The extrinsic, individual, or ac- cidental aims are various, such as desire for money, fame, notoriety, public good-will, recreation, personal pleasure, etc. At one time the intrinsic aim may predominate, at another, the extrinsic. Hume, when writing each work, was undoubtedly influenced by both these classes of motives. And whether the in- trinsic or the extrinsic aim predominated, when he was writing the Inquiry, cannot easily with positive certainty be determined. It is recognized, of course, by all competent critics, that in the Treatise the in- trinsic aim predominates. But on the other hand, it may be conceded that in the Inquiry the extrinsic aims, formally at least, appear to preponderate. The above admission wiU perhaps be regarded as a virtual surrender of the point in issue. Such, how- ever, it is by no means intended to be. It is made merely for the sake of clearness and precision, con- stituting as it does a new basis for further discussion. Hume's primary aim in the Treatise, as has been re- peatedly stated, was the presentation of a true theory of knowledge which would be of service to science, and which would help to overthrow rationalistic meta- physics. And his primary aim in the Inquiry, as has now been acknowledged, was, possibly, external conditions or individual circumstances. But from AIM, SUBJECT-MATTEE, AND METHOD. 39 these propositions to draw the conclusion that the aim of the Inquiry is essentially different from that of the Treatise, before examining at aU the ground of the difference in the statement of these two aims, would not only be premature, but unjustifiable. The difference in aim, as above conceded, between the two works, is really but apparent, and admits of easy explanation. One of Hume's chief objects, in writ- ing the Inquiry, was to caU the attention of the public to the system of philosophy expounded in the Treatise. In a letter to Home, in 1742, he said that there was a demand for the Essays — Moral and Political. " I am . . . told that Dr. Butler has everyTyhere recom- mended then; . . . They may prove like dung with marl, and bring forward the rest of my philosophy, which is of a more durable, though of a harder and more stubborn nature. ' "■ Then he wrote the Inquiry, partly at least, for the ptirpose of helping the Essays to bring forward the Treatise. Hence this motive, although nominally extrinsic, is properly speakiag in- trinsic, siuce Hume's ultimate object was to carry the reader beyond the abridged account of his system to the complete exposition. And it must finally be con- cluded liiat Hume, when writing the Inquiry, was actuated more by intrinsic than by extrinsic motives ; for in reality the former were paramount, although it may seem that formally the latter predominated. Furthermore, it may be observed that the primary intrinsic aim of both works is exactly the same, viz., the presentation of a true theory of knowledge which might be of service to science,^ and which would sub- ' Burton, Life^ I, p. 143. 2 Of. Orr, David Bume, p. 85. 40 Hume's treatise and inquirt. vert rationalistic metaphysics. That this aim is sought in a different way in each book is due to the different circumstances under which the books were written; and from these changes in circum- stances there naturally resulted corresponding changes in the extrinsic aims. Hume gave a detailed and abstract account of his theory of knowledge in the Treatise, because he expected to establish a great philosophical reputation by means of the work. In this object he had apparently failed. Then he ap- pealed from the tribunal to the forum, and presented in a popular manner the more easy and interesting parts of his system. Also, before publishing the Treatise, he withdrew some portions of it and modified others, in order that it might give "as little offence as possible," because he intended to present a copy to Dr. Butler, and hoped to obtain the applause of the learned world. The learned world, however, took but little notice. Hence, in the Inquiry, he restored these omitted portions, and expressed his views on religious questions more freely and less charitably. He thought thereby to rouse the learned world up a little, and after a while, indeed, he succeeded. Hume had now attained to a position such that hos- tility from theological quarters tended rather to ad- vance his fame than to impede it. . Besides, opposi- tion from those whose good opinion one does not expect to win is often pr.eferable to blank indifference. In short, the inevitable conclusion is, that the in- trinsic aim of both works is paramount, and also identical; but that the extrinsic aims are different. This is equivalent to saying that Hume's real object, in his philosophical vmtings, was ever the same; but AIM, SUBJECT-MATTER, AND METHOD. 41 that the means which he adopted for the realization of this end varied at different times, according as the circumstances seemed to require. This view, it may- be added, is in perfect accord with the character of the man. Though firm in his rights, steadfast in his principles, inflexible in his purposes, Hume was es- sentially a child of experience, ever willing to learn wisdom from the eternal laws of nature, and to con- form, in accidentals, to the ways of the world. The distinction just made between Hume's intrinsic and extrinsic aims, although in itself simple enough, is one that has never before been made. Yet by means of it, the obscurity which has so long prevailed upon the question, whether the aim of the Inquiry is the same as that of the Treatise, is entirely removed. § 7. Hume's Subject-matter. — By subject-matter here is meant, not the particular topics which are dealt with in the Treatise and Inquiry, but rather Hume's philosophy, in its general characteristics, as it is presented in these two works. The philosophy of human nature, the science of man, or moral philos- ophy—all of which terms the author uses synonym- ously — comprises all the more important sciences which deal with human life or conduct. It is divided into theoretical philosophy, and practical;^ or more specifically, into logic, morals, politics, and criticism." Both these modes of classification are given in the Treatise, but only the former in the Inquiry, probably because in his later writings Hume did not intend to present his complete system. The science of man is, therefore, on the one hand, a psychological account iIV, p. 3; cf. II, p. 235. s I, pp. 303, 307. 42 Hume's treatise and inqijiey. of human knowledge, and on the other, a scientific treatment of motives and conduct, based on the theory of knowledge previously expounded. As already stated,^ it is only the first of these divisions of the science that comes within the scope of this work. The philosophy of human nature, as contained in the Treatise and Inquiry, rests on two fundamental principles, the sensational origin of ideas, and the representational theory of knowledge. Hume pro- fesses to establish the validity of the former prin- ciple by means of proofs;'' but the latter he simply assumes, accepting it without question from preceding philosophers. He is thus, at the outset of his specula- tions at least, an empiricist, and an idealist. While he is a phenomenalist, he does not hold consistently to either the cruder or the finer form of the hypothesis of cosmothetie idealism. Occasionally he speaks as if knowledge were a tertium quid interposed between the mind and the external object, but again, as if it were merely a modification of the mind itself. He accepts implicitly Locke's definition of knowledge — the per- ception of the agreement or disagreement of two ideas. Hence he is equipped with what he regards as the only true criterion of certainty.* And since he as- sumes that the only objects of knowledge are states of consciousness, or impressions, ideas, and relations, he regards the science of man as a propaedeutic to all the other sciences. Of course, Hume does not always hold consistently to his assumption respecting the subjectivity of knowledge. He conforms himself, > P. 4. 2 Of. p. 51, below. » Of. I, pp. 311, 324, 371; IV, pp. 13, 51, 124, 125. AIM, StTBJECT-MATTEE, AND METHOD. 43 sometimes consciously, sometimes tmeonseiously, to "the manner" of thinking and speaking with "the viilgar. "^ It may be further noted that the Treatise and Inquiry contain two very important, and at the same time different elements, one logical, the other psychological. The logical element is negative in tendency, and professes to prove, from an examination of the human understanding, that certain supposed kinds of knowledge— for example, metaphysics— are impossible. The psychological element, on the other hand, is positive in tendency, and undertakes to show, in a similar manner as before, that certain kinds of knowledge— for example, "a mental geography"— are possible. It is sufficient to remark here that both these elements, as well as the conflict between them, stand out more prominently in the Treatise than in the Inquiry. The significance of this difference will be dealt with later." There has been considerable discussion on the ques- tion, whether Hume was perfectly sincere in adopting from Locke and Berkeley the fundamental principles of his system. Mamiani* afSrms that it is a great misconception to think that the author of the Treatise was serious. And Hamilton* asserts that Hume merely took up the conclusions of his predecessors, without indorsing them, and demonstrated the im- possibility of establishing a philosophical system on a theory of pure empiricism. On the other hand, II, pp. 491,499; IV, p. 29 n. ' Pp. 117-125; 127-132; 299-304. 8 Simon, Berkeley's PrmcipUs of Human Knowledge, App. n, p. 194. * Discussions, p. 87. 44 Hume's teeatise and inquibt. Seth declares:^ "There is no reason to doubt that [Hume] accepted in perfect good faith the funda- mental positions from which he argued." The chief- reasons for the former opinion are: .{1) The ab- surdities into which Hume's reasoning sometimes led him; and (2) the numerous admissions which he made in the Treatise regarding the probable ineffectiveness of his arguments.^ "When these considerations, how- ever, are weighed against the serious statements of the author in the introduction to his work, in the appendix, and in several letters,' there can be no doubt that the balance of evidence is in favor of the latter view.* Moreover, it is well known that Reid held for many years, in perfectly good faith, essen- tially the same philosophical presuppositions as his skeptical antagonist. In a letter to Hume in 1763, he made the following significant admission:" "Your system appears to me not only coherent in all its parts, but likewise justly deduced from principles commonly received among philosophers." The sub- sequent remark of Seth,° that "in refusing to look upon Hume's system as a substantive or serious ac- count of the nature of things, we may thus fairly claim to be taMng him at his own valuation," is ob- viously open to criticism. We cannot regard one, nor a few of Hume's statements as a just valuation of his system of philosophy, without taking account of the •Scottish Phil., p. 68; cf. Knight, Hume, p. 130; Mill, Ex- amination of Hamilton, p. 554; Orr, David Hume, pp. 94-101. ! Of. pp. 416, 461, 468, 544. » Burton, Life, I, pp. 31, 62, 65, 108. * Of. Mind, Vol. XI, p. 269. 6 Burton, Life, 11, p. 155. 'Scottish Phil., p. 70. AIM, SUBJECT-MATTER, AND METHOD. 45 circumstances under which they were made, and with- out giving due consideration also to counter state- ments, when such, of a directly opposite nature and tendency, appear in his writings. Orr's estimation, on this question, is the true one. "There is abundant evidence," he says,^ "that Hume regarded himself as an original discoverer in philosophy. He speaks re- peatedly and complacently of 'my system.' He is confident that he has succeeded where others had failed in establishing the theory of human nature upon a just foundation." § 8. Hume's Method.— Wh\\& the subject-matter of Hume's philosophy is but vaguely defined in the title of his chief work — A Treatise of Human Nature,— ihQ method is clearly indicated— "An at- tempt to introduce the experimental method of rea- soning into moral subjects." Nevertheless, differ- ent opinions have been expressed concerning it.^ The view of Morris,^ viz., that Hume's method is "the method of empirical psychology," derived from that of "physical inductive science," is sub- stantially correct. For by experimental method Hume meant simply the scientific or inductive method, as this is now generally understood. It is no aston- ishing reflection to consider, he says,* "that the ap- plication of experimental philosophy to moral sub- jects should come after that to natural at the distance of above a whole century; since we find in fact, that there was about the same interval betwixt the origins ' David Bume, p. 104. 2 Of. Long, Ueier Hume's Lehre v. d. Ideen u. d. Substance, p. 37; Hodgson, The Philosophy of Befleotion, 1, p. 239. 3 British Thought and Thinkers, pp. 247, 253. *P. 308; cf. IV, p. 174. 46 Hume's teeatisb and inquiky. of these sciences; and that reckoning from Thalbs to SocEATES, the space of time is nearly equal to that betwixt My Lord Bacon and some late philosophers in England,^ who have begun to put the science of man on a new footing, and have engaged the attention, and have excited the curiosity of the public." He thinks it evident, "that the essence of the mind being equally unknown to us with that of external bodies, it must be equally impossible to form any notion of its powers and qualities otherwise than from careful and exact experiments, and the observation of those particular effects, which result from its different circumstances and situations."^ Hume thus includes, under the term experimental method, observation of one's own mind, and observation of other minds, human and animal, in so far as the nature of mental states and'^ processes can be subjectively perceived, interpreted i by conduct, or disclosed by a study of physiology.) He employs not merely the ordinary method of em-'; pirical psychology in its two aspects, subjective and! objective, but also, to some extent, the comparative! | genetic, and historical methods.' "The experimentali method" is not to be confused, of course, with the method of experimentation as now employed in what is commonly eaUed the "new psychology." For although Hume resorted at times to experiment, in order to confirm, or to illustrate his reasoning, and 1 " Mr. Locke, my Lord Shaftslury, Dr. Momdeville, Mr. HutoUnson, Dr. Butler, etc." — ^The space of time is not so nearly equal as Hume would represent, being from Thales (640 or 625) to Socrates (469) 171 (or 156) years, and from Bacon to Locke 71 years. 2 P. 308. 1 Of. I, pp. 364, 365, 468, 469. , ... AIM, SXJBJECT-MATTEB, AND METHOD. 47 declared that "all our perceptions are dependent on our organs, and the disposition of our nerves and animal spirits,"^ lie was after all but a worthy fore- runner of the modern school of experimental psy- chologists. -^ In the Inquiry also, Hume emphasizes the experi- mental or scientific method. In the first section Ire says that "the only method of freeing learning" froni abstruse metaphysical questions "is to inquire seri-| ously into the nature of human understanding, and! show, from an exact analysis of its powers and capac- \ ity, that it is by no means fitted for such remote and , abstruse subjects.'"' It will be noted, however, that, in addition to this statement, he asserts:' "Accurate and just reasoning is the only catholic remedy, fitted for aU persons and aU dispositions; and is alone able to subvert that abstruse philosophy and metaphysical jargon, which, being mixed up with popular super- stition, renders it in a manner impenetrable to care- less reasoners, and gives it the air of science and wisdom." Also in the twelfth section he affirms;* "To begin with clear and self-evident principles, to advance by timorous and sure steps, to review fre- quently our conclusions, and examine accurately all their consequences; though by these means we shall make both a slow and a short progress in our systems ; are the only methods, by which we can ever hope to reach truth, and attain a perfect stability and cer- tainty in our determinations." These last two pas- sages, if interpreted with strict literalness, are incon- sistent with Hume's former statements; for here he seems to abandon the inductive method of the scien- >P. 498. 2 P. 9. 'P. nid. *P. 123. 48 hxtmb's treatise and rNQumT. tists, and to adopt the deductive metliod of the phi- losophers. But the truth of the matter is that the "accurate and just reasoning" which is spoken of in the first passage, is conversant with matters of fact; and the "clear and self-evident principles" which are referred to in the second, are arrived at by means of induction. Although Himie, in both works,^ seemed to make certain assumptions, and then reasoned from these according to the deductive method, yet in most cases, these assumptions are ultimately based, im- plicitly at least, on observation and experiment. In the Inquiry, the author did not discard, nor even sub- ordiaate his experimental method. For the result of his investigation is but a "mental geography, or de- lineation of the distinct parts and powers of the miad" ;^ that is, a description of impressions and their copies, in their coexistence and succession. Like- wise, without adopting any of the distinctive methods of experimental psychology, he introduced, as in the Treatise, a few experiments in the psychology of sen- sation, in order to prove, or to illustrate his argu- ments.* It is obvious, therefore, that Hume adopts the scien- tific method in both works. The deductive element of this method although perhaps not more generally employed in the later work than in the earlier, is more fully recognized in the first section of the Inquiry than in the introduction to the Treatise of Human Nature, This change may be explained, ia part, on psycholog- ical grounds ; Hume at first expected to obtain extra- ordinary results from the use of his experimental 1 Of. I, pp. 324, 326, 339; IV, pp. 13-15, 124, 125. 2 P. 10; cf. pp. 15, 17. Of. IV, pp. 15, 124, 125. 49 method. But the change is probably due, in the main, to the difference in subject-matter of the two introductions; the one being an introduction to tbe science of man, the other an introduction to the theoretical part of the science. Hence, when 'the au- thor afterwards takes up the discussion of practical philosophy, in the Inquiry ccmceming the Principles of Morals, he again emphasizes the importance of the inductive element. Regarding the nature of moral distinctions he asserts:^ "As this is a question of fact, not of abstract science, we can only expect success, by following the experimental method, and deducing general maxims from a comparison of particular in- stances." Hume designated the Treatise of Human Nature, "An attempt to introduce the experimental method of reasoning into moral subjects," because in the work he employed the inductive method of the natural scientists, rather than the deductive method of the rationalistic philosophers. This method he followed in the Inquiry ia a like manner, and sub- stantially to the same extent as in. the Treatise. 1 IV, p. 174. CHAPTER III. PEECEPTIONS: THEIR NATURE, AND CAUSE. § 9. The Nature and Classification of Perceptions. —Although Hmne, in his psychology, adopted an atomistic view of mind, he did not carry out his analysis of the concrete phenomena of consciousness stiiSciently far to enable him to distinguish between the purely psychological standpoint, and the epistemo- logical. The ultimate elements of consciousness are, for him, not merely structural, but also functional. "While together they constitute the stream of thought, each one separately has meaning, it knows. Failure to perceive the true significance of this fact has been one of the chief reasons why, on the one hand, the merits of Hume's system have seldom been fuUy real- ized, and why, on the other, the philosophy of human nature has been subjected to much irrelevant and ' inane criticism. In the Treatise, all mental phenomena are called perceptions. These are the only objects of human knowledge.^ Although coojoined, they are not con- nected, they all are distinct and separable; that is, perceptions generally do not exist separately, but they all may be thought of as existing separately, and con- sequently, may all exist as distract and separate en- tities." They are complex, or, simple, according as • Cf. pp. 311, 324, 327, 339, 371, 396, 408, 466, 483, 493, 503, 518, 523, 558. a Cf. pp. 319, 326, 343, 370, 376, 381, 388, 456, 463, 495, 518, 540, 558, 559. 50 PERCEPTIONS: THEIR NATURE, AND CAUSE. 51 they can, or camiot be resolved into simpler elements.^ Perceptions form two general classes, impressions, and ideas. Impressions are always the first to appear in the mind. Of this Himie gives two proofs:^ (IV, "Every simple impression is attended with a corre- spondent idea, and every simple idea with a corre- spondent impression." \{2) "Wherever by any ac- cident the faculties, which give rise to any impression, are obstructed in their operations [or when the organs of sensation have never been put in action to produce a particular impression] , not only the impressions are lost, but also their correspondent ideas." Hence it follows that all ideas are copies of impressions. Sim- ple ideas differ from their corresponding impressions; only through their less degree of force, vivacity, or liveliness.' But complex ideas differ also in. some other— although not important— respects from the complex impressions from which they were derived; for instance, they are less perfect or complete, and their details are more confused.* "With regard to force or liveliness, impressions and ideas merge into each other, or blend by imperceptible degrees, and consequently, at times, cannot be distinguished by introspection." Impressions are of two kinds, those of sensation, and those of reflection. Impressions of sensation are those that arise "in the soul originally, from unknown causes," by means of the senses, also sensations of "heat or cold, thirst or hunger, pleasure or pain." Impressions of reflection "arise mostly iP. 312; cf. p. 328. 2 P. 314. 8 Cf. pp. 311, 312, 327, 396, 452. *P. 313; for an apparent contradiction, see II, p. 113. 6 Pp. 311, 421. 52 humb's treatise and inquiey. from ideas," but sometimes directly from impressions of sensation.^ They are the passions, emotions, de- sires, and aversions.^ There are also two kinds of ideas, those of sensation, and those of reflection. These correspond, respectively, to the two kinds of impressions, being copies of them.* And since ideas may produce "the images of themselves in new ideas," there arise "secondary ideas, which are images of the primary."* Besides the classification of ideas into those of sensation and those of reflection, there is an- other division into those of memory, and those of imagination. Ideas of memory differ from those of imagination by their fixed order of appearance in the mind, and by their greater degree of force, vivacity, or liveliness." Probably through ignorance of continental philos- ophy, Hume mistakenly expresses the opinion that the distinction which he makes between impressions and ideas settles the controversy concerning innate ideas. Hence, he regards all impressions as innate, and all ideas as not innate.' In the case of different shades of color, for example, blue, he admits an exception to his general principle that impressions always precede their corresponding ideas, but thinks the instance is so singular that the general maxim need not be altered.'' True, a similar exception may be observed in the degrees of every distinct class of sensations— as indeed Hume seems to imply,*— not only in the iP. 311; cf. II, p. 76. "Pp. 316, 317, 324, 340. »P. 317. «P. 316. 6 P. 317, 318, 386, 387, 407, 409, 545. 61, p. 316. 'I, p. 315. SI, p. 316; ef. IV, p. 16. PEECEPTIONS: THEIE NATUBB, AND CAUSE. 53 sphere of color, but also in that of sotmd, taste, etc. These instances, however, strictly speaking, are only- apparent exceptions to Hume's maxim. The differ- ent shades of blue are but different degrees of gray, or of brightness, mixed with the color tone. And ideas may be increased or diminished in quantity or in intensity by the imagination alone. Of the three sections which originally dealt with these topics, only one appears in the Inquiry. The two entitled, "Division of the Subject," and "Of the Ideas of the Memory and Imagination" are en- tirely omitted. These omissions were doubtless made for the sake of brevity, and do not seem to be signifi- cant. Some of Hume's critics, however, have thought otherwise. Their views will be examined presently, after the points on which there is no controversy have been stated. As in the Treatise, aU mental phenomena are called perceptions. These are the only objects of knowledge.^ Perceptions are conjoined, but not connected; they all may be regarded as distinct and separate existences.^ Perceptions fall into two classes, impressions, and ideas. That impressions are the first to appear in the miud, the same two proofs are given as formerly.* Hence, aU id^as are copied from inipressions, and differ from them only in degree of force, vivacity, or liveliness.* The exception to the general rule, — that all simple ideas are copies of im- pressions,— is noted as before in the case of color.'* And the controversy on innate ideas is supposed to be settled by the decision that all impressions are 1 Cf. pp. 13, IS, 51, 52, 61, 64, 125. »0/=. pp. 27, 61, 90, 126, 134. »P. 15. iPp. 13, 14, 17; cf. II, p. 113. sp. le. 54 htjme's treatise and inquibt. innate, and all ideas are not innate.^ Thus far, there is complete agreement between both works; on some other questions there is ground for discussion. With regard to impressions and ideas, Hume as- serted in the Treatise that it is impossible at times to perceive, by means of introspection, the difference between them. "It sometimes happens, that our im- pressions are so faint and low, that we cannot dis- tinguish them from our ideas. "^/ Yet in the Inquiry- he says :' " [The memory and imagination] may mimic or copy the perceptions of the senses ; but they never can entirely reach the force and vivacity of the orig- inal sentiment. . . . The most lively thought is still inferior to the dullest sensation." The contrar diction here is only apparent. What Hume means, in the latter passage, is that, under normal conditions and as a general rule, "the most lively thought is still inferior to the dullest sensation." He grants that there are exceptions, for he asserts that when the mind is "disordered by disease or madness," impressions and ideas become "altogether undistinguishable. "* In the Treatise he made several statements of exactly similar import." The position of the earlier work, viz., that it is sometimes impossible to distinguish impressions from ideas by means of introspection, is psychologically correct. And Hume would undoubt- edly have expressed the same view in the Inquiry, had he treated the subject fuUy, or had he written solely for the philosophers amd not also for the public. Brede* states that the distinction between simple 'P- 17n. 2 p. 311; cf. p. 421. »P. 13- *P. 13; cf. pp. 57, 124. 6 Pp. 311, 421. ^Der UntersoTiied d. Lehren B., p. 30. PERCEPTIONS: THEIE NATURE, AND CAUSE. 55 and complex ideas is omitted in the later work, and thinlis that this omission is due to Hume's desire not to emphasize the separateness of simple ideas, since soon after writing the Treatise the author discovered that he could not unite the separate ideas so easily as he formerly thought he could. It may be admitted that simple and complex ideas are not defined iu the Inquiry. But the cause assigned by Brede is evi- dently not the real one. For Hume not only still holds that all perceptions are distiact and separate, and may be thought of as separa.te existences,^ but he speaks of simple and complex ideeis in a manner implying the same distinction as that made in the Treatise. Incidentally, he remarks:^ "Complex ideas may, perhaps, be weU known by definition, which is nothing but an enumeration of those parts or simple ideas, that compose them." The difference here recognized, between simple and complex ideas, was not pointed out with the same fulness and clearness of detail as in the earlier work, because the author now aimed particularly at conciseness of statement. The omission is of no special significance. Selby-Bigge' asserts that, in the Inquiry, the dis- tinction between "impressions of sensation and reflec- tion" is omitted. But he neglects to mention that it is repeatedly assumed. For, instance, in section vii Hume states:* "It seems a proposition, which will not admit of much dispute, that all our ideas are nothing but copies of our impressions, or, in other words, that it is impossible for us to think of any- 1 Cf. 1, p. 559; rV, pp. 27, 61, 90, 134. 2 P. 51; cf. pp. 14, 15, 18. 'Hinn^s Enquiries, p. xii. *P. 51; cf. pp. 17, 38 n., 40, 52, 53, 61, 64, 65. 56 Hume's treatise and inquirt. thing, which we have not antecedently felt, either by our external or internal senses." He implies, of course, that the impressions and ideas of the internal senses are those of reflection, as distinguished from sensation. As he said in the earlier work,^ "the idea of necessity" must be derived "from some internal impression, or impression of reflection." In fact, Hume speaks of impressions and ideas of reflection in the same manner, and seems to attribute to them the same origin in both books. Thus in the Treatise he says :" ' ' This idea of pleasure or pain, when it re- turns upon the soul, produces the new impression of desire and aversion, hope and fear, which may prop- erly be called impressions of reflection, because de- rived from it." And in the Inquiry he asserts:* " [The idea of power] is an idea of reflection, since it arises from reflecting on the operations of our own mind." Explicit treatment of impressions of reflec- tion was omitted, in the later work, simply for the sake of brevity, as was explicit mention of them often omitted in the earlier, for the same reason. "I shall only observe before I proceed any farther," remarked Hume in the Treatise,* "that though the idea of cause and effect be derived from the impressions of reflection as well as from those of sensation, yet for brevity's sake, I commonly mention only the latter as the origin of these ideas; though I desire that whatever I say of them may also extend to the former." It was evidently for a similar reason that the classification of primary and secondary ideas was not given in the Inquiry. For in the Treatise Hume said that the limitation of his maxim of "the priority iP. 460. tp. 317. 3 p. 53. 4 p. 380. PERCEPTIONS: THEEB NATTJEE, AND CAUSE. 57 of impressions to ideas," arising from the recognition of the relation of secondary ideas to primary, was "an explanation" of his general principle, rather than "an exception" to it.^ As several writers" have pointed out, the distinc- tion between the ideas of memory, and those of imagi- nation is omitted in the later work. When dealing with this subject Hume is not only indefinite, but also inconsistent. In the Treatise ideas of memory are differentiated from those of imagination by two char- acteristics :* their fixed order, and their greater force. At first, the former* characteristic is regarded as be- ing the more important, but afterwards, the latter." Again, not only may ideas of memory be so vivid, that they resemble impressions, and are called im- pressions of memory;' but they may also degenerate to such a degree as to become indistinguishable from ideas of imagination.'' And on the other hand, ideas of imagination, through repetition, may become so strong and vivid that they are mistaken for ideas of memory.^ Grimm's treatment of this question is ex- ceedingly plausible, and is probably the best that has been given. His argument, in brief, is as follows:* In the early part of the Treatise, Hume regards memory as something self-dependent and entirely different from imagination. But in a later section, ip. 316. ' Of. Pfleiderer, Empirismus u. Skepsis, p. 119 n.; Brede, Der Untersohied d. Lehren B., p. 31; Selby-Bigge, Hwme'a En- quiries, p. xii. >Pp. 317, 318. «P. 318. 6 Pp. 386, 387, 545. «Pp. 384, 385, 387, 407. 1 P. 387. » Pp. 387, 416, 421. ^ Zv/r Qesdh. d. Erhenntnisproblems, pp. 452, 453. 58 Hume's treatise and inquirt. when he enters more deeply into the nature of knowl- edge of experience, and particularly of the causal connection of things, he develops those defects through which memory is almost deposed from its peculiar position, so that it differs from imagination only in degree. On account of these defects, the distinction between the two faculties, at first somewhat strongly emphasized, loses its chief worth. That may be the cause, therefore, why Hume in his second work neglects to enter upon a discussion of this subject. The facts are essentially as Grimm states them, and his conclusion is not entirely without justification. It is certain -that Hume, when writing the Inquiry, was influenced by the desire to avoid the contradic- tions in the earlier work, and that may have been a reason why he neglected to give a fuU treatment of the ideas of memory and imagination. And it is prob- able that he perceived the impossibility of precisely distinguishing between these two classes of ideas, and therefore refrained from making the attempt within the compass of a popular essay. But the chief reason for these omissions was undoubtedly the author's de- sire to secure conciseness of statement; since he im- plicitly distinguishes between the ideas of memory and those of imagination, and assigns to the former, in contrast with the latter, the chief functions ascribed to them in the Treatise. ""Whenever any object is presented to the memory or senses," he says,^ "it immediately, by the force of custom, carries the im- agination to conceive that object, which is usually conjoined to it; and this conception is attended with a feeling or sentiment, different from the loose iIV, p. 41; cf. pp. 13, 17, 39, 43. PEECEPTIONS: THEIR NATURE, AND CAUSE. 59 reveries of the fancy." If Hume had revised, or rewritten the earlier work, instead of only portions of it, all the distinctions fornaerly made between memory and imagination would, in all probability, have been expressed in the later. Even the incon- sistencies that appear in the fuller statement are verbal, rather than real. With care they might have been avoided. They cannot, therefore, fairly be re- garded as having any specific influence on the author when he wrote the Inquiry. Concerning the question of the nature and classifi; cation of perceptions, it is evident that the position of the two works is practically the same. On all the more important topics there is perfect agreement. On minor points, of course, owing chiefly to omissions' in the Inquiry, there are some differences observable. But these are differences of treatment, not of doctrine. Since the distinctions which were explicitly made, in the earlier work, are either reasserted, or implied in the later, the omissions do not seem to have any significant bearing on Hume's philosophical positioi^. § 10. The Cause of Perceptions. — The treatment of the cause of perceptions is rendered somewhat diffi- cult, owing to the ambiguity attaching to the word cause. True, it was one of Hume's main contentions, one of the theses which he especially aimed to prove, that cause means only invariable antecedent.^ ' ' Thus upon the whole we may infer," he declares,'' "that when we talk of any being, whether of a superior or inferior nature, as endowed with a power or force, proportioned to any effect ; when we speak of a neces- 1 1, pp. 375 and ff.; IV, pp. 51 and fif. 2 1, p. 457; cf. IV, pp. 60, 61. 60 Hume's treatise and inquirt. sary connection betwixt objects, and suppose, that this connection depends upon an efficacy or energy, with which any of these objects are endowed; in all these expressions, so wppUed, we have really no distinct meaning, and make use only of common words, with- out any clear and determinate ideas." Hume, how- ever, was obliged to use the language at his disposal, and not infrequently he speaks of cause as if imply- ing by it producing power. Yet if the instances in which he seems to use cause in this sense be examined, it will often be discovered that the real meaning of the word is but invariable antecedent.^ Having defined what he meant by cause, he was at liberty to employ the terms he found most convenient for his purpose. No doubt, at times he found it convenient to use cause in an improper sense, perhaps realized that it was impossible to avoid such use. But in these in- stances he is inconsistent, and the inconsistency must be acknowledged. Concerning the cause of perceptions, that is, their invariable antecedent, Hume gives two different ac- counts.^ These may be called the epistemological explanation, and the physiological, viz., (1) "What is the cause of perceptions according to the philosophy of human nature? (2) What is the cause of percep- tions according to natural science ? The two questions require separate treatment. I. "What is the cause of perceptions according to Hume's system of philosophy, the epistemological ex- planation? In the Treatise, the author says that the impressions of sense arise "in the soul originally, 1 Cf. I, pp. 316, 317, 340, 343, 385; IV, pp. 16, 17, 60, 64, 125. !I, pp. 313, 314. PERCEPTIONS: THKre NATURE, AND CAUSE. 61 from unknown causes." When tlie impressions dis- appear, they leave their traces or copies; these are ideas of sensation— primary ideas of sensation, from which, in turn, may arise secondary ideas. Impres- sions and ideas of sensation also give rise to impres- sions of reflection — passions, desires, and emotions. These latter "are copied by the memory and imagina- tion and become ideas [of reflection] ; which perhaps in their turn give rise to other impressions and ideas. "^ The order of genesis then is as follows: impressions of sensation, ideas of sensation, impressions of reflec- tion, and ideas of reflection; impressions of sensation being the cause of ideas of sensation — sometimes also the cause of impressions of reflection," — ideas of sen- sation the cause of impressions of reflection, and im- pressions of reflection the cause of ideas of reflection. Although the greater part of this account is omitted in the Inquiry, Hume's position may easily be ascer- tained. As in the Treatise, he distinguishes between impressions and ideas, and states repeatedly that all ideas arise from the external or internal senses, that is, from sensation and reflection.* Thus there is im- plied the same classification of perceptions as before ; and the impressions of sensation and reflection are, respectively, the cause of their corresponding ideas. True, it is not explicitly stated that the impressions of reflection, in every instance, arise from impressions or ideas of sensation. Grimm* suggests that perhaps Hume wished thus to escape one of the contradictions involved in the earlier work, viz., that of making im- il, p. 317. iCf. 1, p. 317; II, pp. 75, 76. » Of. pp. 14, 15, 17, 40, 51, 52, 53, 61, 64, 65. * ZviT Oesch. d. Erkermtnisprollems, p. 589. 62 Hume's treatise and inquikt. pressions of reflection causally dependent on impres- sions of sensation, instead of merely successive in time. This reason, however, does not seem to have been the real one. For according to Hume, causally dependent simply means invariably consequent. In this sense, Hume again, in the second book of the Treatise of Human Nature, regarded impressions of reflection, which he called secondary, as dependent on impressions or ideas of sensation, which he called original.^ And in a similar manner, in the Inquiry, he not only still holds that ideas are dependent on im- pressions—as Grimm indeed admits,"— but also that the impression of reflection from which the idea of cause is derived is dependent on impressions of sensa- tion.° It seems as if the omission in the Inquiry was due to the author's desire for brevity of treatment, rather than to any change of view, or endeavor to avoid contradictions. Thus far, there has been assigned no cause of the im- pressions of sensation. Concerning these, in a note to the first section of the Treatise, Hume asserts:* "By the term of impression I would not be understood to express the manner, in which our lively perceptions are produced in the soul, but merely the perceptions themselves." To this statement there is nothing corresponding in the Inquiry, except a note on innate ideas, which contains the following sentence:" "But admitting these terms, impressions and ideas, in the sense above explained, and understanding by innate,] what is original or copied from no precedent percep-' III, pp. 75, 76. s Zw &esch. d. Erkermtmsprohlems, p. 559. 3 Pp. 53, 62, 65; Of. pp. 14, 15, 17, 40, 51, 52, 61, 64. *P. 312. 6 p. 17. PERCEPTIONS: THEIB NATURE, AND CAUSE. 63 tion, then may we assert, that all our impressions are innate, and our ideas not innate." Thus he implies that impressions are the cause of ideas, but concerning the cause of impressions he has nothing now to say. In the second section of the Treatise, however, he de- clares:^ "The examination of our sensations belongs more to anatomists and natural philosophers than to moral; and therefore shall not at present be entered upon." In the Inquiry, there is nothing correspond- ing to this statement. The sentence just quoted seems to imply that Hume wiU afterwards deal with impres- sions. But as this investigation "belongs more to anatomists and natural philosophers than to moral, ' ' the explanation must be physiological rather than epistemological. Hence arises the second question. II. What is the cause of perceptions according to natural science, the physiological explanation? As already stated, thus far, in neither work, does Hume assign any cause of the impressions of sensation. In the Treatise, he remarked that the examination of the impressions of sense belonged more to anatomists and natural philosophers than to moral, and therefore should not at present be entered upon. Consequently, when he afterwards gives a physiological explanation of perceptions, it might naturally be supposed that this explanation applies only to impressions. The treat- ment, however, is too general to bear this interpreta- tion. For when he discusses the subject in Part II, and again in Part IV, he speaks, not of the cause of impressions, but of the cause of perceptions, includ- ing the cause of ideas as well as that of impressions. In the Treatise are such passages as the following:* >P. 317. "P. 365. 64 Hume's treatise and inquiey. "I shall therefore observe, that as the miad is en- dowed with a power of exciting any idea it pleases; whenever it dispatches the spirits into that region of the brain, in which the idea is placed; these spirits always excite the idea, when they run precisely iato the proper traces, and rummage that cell, which be- longs to the idea."— "When we press one eye with a finger, we immediately perceive all the objects to become double. . . . But as we do not attribute a continued existence to both these perceptions, and as they are both of the same nature, we clearly perceive, that all our perceptions are dependent on our organs, and the disposition of our nerves and animal spirits. ' '^ These quotations clearly indicate that the physiolog- ical cause of perceptions is cerebral and neural proc- esses—including, of course, the movements of animal spirits. Cerebral and neural processes are the in- variable antecedents of perceptions. In still another passage Hume declares:^ "I would answer, that we must separate the question concerning the substance of the mind from that concerning the cause of its thought; and that confining ourselves to the latter question we find by the comparing their ideas, that thought and motion are different from each other, and by experience, that they axe constantly united; which being all the circumstances, that enter into the idea of cause and effect, when applied to the opera- tions of matter, we may certainly conclude, that motion may be, and actually is, the cause of thought and perception." It is true, he admits that this conclusion "evidently gives the advantage to the materialists above their antagonists. "= But the ad- 'P. 498. 8 P. 530. 3 P. 532. PERCEPTIONS: THEIB NATTJBE, AND CAUSE. 65 mission, standing as it does against several contrary statements/ has no philosophical importance.^ It probably occurred through the author's over zeal in his opposition to the "spiritualists" with their "meta- physical entities." Although, in the Inquiry, there is no definite answer given to the question concerning the physiological cause of perceptions, there are some statements which contain, at least, a partial answer. In section ii,* Hume admits that, when the mind is "disordered by disease or madness," ideas may "arrive at such a pitch of vivacity" that they are indistinguishable from impressions ; and in section xii,* he implies that many "perceptions arise not from any thing ex- ternal," but from the condition of the organism, or from a certain state of the brain or nerves. These and other passages" of like import clearly mean that perceptions are caused, that is, invariably preceded, by cerebral and neural processes, or by movements of the animal spirits." Statements confirming this conclusion may be found in Hume's other writings. In the posthumous work, the Dialogues concerning Natural Religion, for example, Philo asks:^ "What peculiar privilege has this little agitation of the brain which we call thought, that we must thus make it the model of the whole universe ? ' ' The conclusion now reached, viz., that the physio- logical cause of perceptions is cerebral processes, seems 1 Of. pp. 385, 546. s Cf. pp. 532, 533. 3 P. 13._ 'P. 125. "S^ pp. 15, 55, 57, 124. 6 Of. Huxley, Bvme, pp. 76, 78; Porter, Bdence and Senti- ment, p. 311. T 11, p. 396. 5 66 Hume's treatise and inquiet. to be inconsistent with a statement made in the sec- ond section of the Treatise, to the effect that impres- sions of sense arise in the soul originally "from un- known causes." The explanation, however, is not difficult. In his account of the physiological cause of perceptions, Hume has reference to the immediate cause ; hence his answer, neural and cerebral processes. But when the further question is raised, what is the ultimate cause of perceptions? he has no answer to give. True this question, from the philosophical point of view, is much more interesting than the previous one. But Himie does not attempt to answer it. As he has just said, impressions of sense arise in the soul origiuaUy from unknown causes ; that is, the original, or ultimate cause of impressions is unknown. In an- other passage also, he declares:^ "As to those impres- sions, which arise from the senses, their ultimate cause is, in my opinion, perfectly inexplicable by human reason, and it wiU always be impossible 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." In the Inquiry, almost exactly the same position is assumed in the first part of the twelfth section. "By what argument can it be proved," asks Hume,^ "that the perceptions of the mind must be caused by ex- ternal objects, . . . and could not arise either from the energy of the mind itself, or from the suggestion of some invisible and unknown spirit, or from some other cause stiU more unknown to us?" It is true that, in the later work, the author does not draw a dis- tinction between the question of the immediate cause, 'I. p. 385. 2 p. 125. PEECBPTIONS: THEIE NATUEE, AND CAUSE. 67 and that of the ultimate cause of impressions. Never- theless, this distinction seems to be implied, when he admits that some impressions are produced by neural and cerebral processes, or by the condition of the bodily organism;^ and when, at the same time, he affirms that it is impossible to tell from whence "the perceptions of the mind" arise." Thus Hume leaves the metaphysical question of realism and idealism un- determined, and asserts that it is indeterminable. It is a matter which lies whoUy beyond the power of human understanding. This is the position of the Inquiry as well as of the Treatise. Before concluding the discussion, some reference should be made to the opinions that have been ex- pressed, by interpreters of Hume, regarding his doc- trine of the cause of perceptions. Huxley' states that Hume "fully adopted the conclusion to which all that we know of psychological physiology tends, that the origin of the elements of consciousness, no less than that of all its other states, is to be sought in bodily changes, the seat of which can only be placed in the brain." At the same time, he asserts that "Hume is not quite consistent with himself" respect- ing the origin of impressions of sensation.* Knight takes a somewhat similar view, but he is more reserved in the expression of it. He says :" " [Hume] suggests that, for all that we know to the contrary, material changes may be sufficient to produce mental ones, but he does not teach this dogmatically." He also asserts that Hume is inconsistent in his treatment of 1 Of. pp. 15, 55, 57, 124. " P. 125. *Hume, p. 74. *Eume, p. 72. 'Hume, pp. 143, 144; cf. Porter, Science and Sentirr),ent, p. 311. 68 Hume's treatise and estquiet. the subject, " both in the Treatise, and the Inquiry." Webb declares :i "But though in his psychology [Hume] refuses to recognise either the conceptions or the principles of efficient causation and essential substance, yet in his metaphysics he finds himself compelled to admit that our impressions have a cause, and thus to recognize with Kant the existence of a non-sensuous cause of our sensations." And Seth^ affirms that, "Hume cuts short the question of the cause of our impressions as a transcendental inquiry." Here are several different, and even contradictory statements. One represents that, according to Hume, the cause of perceptions is cerebral processes; an- other that the author, in both works, contradicts him- self; a third that the cause of impressions is a noumenal existence; and still another that the cause of impressions, being a transcendental question, is not investigated. The inconsistencies in these divergent views are accounted for, and at the same time in large measure removed, by the interpretation that has just been given. It is manifest that Hume recognizes a distinction between the immediate cause of perceptions and the ultimate cause. He distinguishes between the immediate and the ultimate causes of phenomena.* He says of his philosophy, that it "pretends only to explain the nature and causes of our perceptions, or impressions and ideas."* He states that the cause of perceptions is motion, movements in the brain or nerves, or of the animal spirits." But the "ultimate 1 Veil of Isis, p. 120 ; of. pp. 87, 121. ^Scottish Phil., pp. 46, 48 j of. I, p. 161; Aikins, PMl. of Eume, p. 44; Speekmann, Hume's metaphysisohe Slcepsis, p. 24. » Gf. I, p. 646; IV, p. 11. Mind, Vol. W, p. 553. CHAPTER V. SPACE AND TIME. § 15. Infinite DwisibiUty.—'PaTi II of the Treatise contains Hume 's doctrine of space and time. In this discussion dialectic skill and profound originality are everywhere manifest. But the author's intellectual power is not organized. His visualizing imagination and erroneous presuppositions color and distort the ar.gument to such an extent that this discussion, not- withstanding the exceedingly great merits of the ex- position, is the most obscure, intricate, vacillating, and even self-contradictory in all his philosophical writings. Hume indeed seems to have been somewhat conscious of the difficulties inherent in this part of his system, for he entered upon his task with unusual care and forethought. In the last section of Part I he dealt with general ideas, thus preparing the way for the treatment of space and time in Part II. And here, before grappling with his subject proper, he dis- posed of the minor questions concerning the infinite divisibility of ideas, and the infinite divisibility of space and time. Ideas, according to Hume, are not infinitely divis- ible, because : (1) "the capacity of the mind is limited, and can never attain a full and adequate conception of infinity"; and (2) "whatever is capable of being divided in infinitum, must consist of an infinite num- ber of parts." Hence it foUows, "that the idea, which we form of any finite quality, is not infinitely 89 90 humb's treatise and inquiet. divisible, but tbat by proper distinctions and separa- tions we may run up this idea to inferior ones, which will be perfectly simple and indivisible."^ It is not quite clear, however, what the nature or characteristics of these indivisible ideas are. For Hume further asserts:^ "When you teU me of the thousandth and ten thousandth part of a grain of sand I have a distinct idea of these niuabers and of their different proportions; but the images, which I form in my mind to represent the things themselves, are nothing different from each other, nor inferior to that image, by which I represent the grain of sand itself, which is supposed so vastly to exceed them. What consists of parts is distinguishable into them, and what is distinguishable is separable. But what- ever we may imagine of the thing, the idea of a grain of sand is not distinguishable, nor separable into twenty, much less into a thousand, ten thousand, or an infinite number of different ideas." Yet on the fol- lowing page, he remarks: "This however is certain, that we can form ideas, which will be no greater than the smallest atom of the animal spirits of an insect a thousand times less than a mite." Hume's position seems to be this : one can form an idea about anything whatever that can be presented ia imagination, no matter how small it may be ; but this idea itself, if of a very minute object, can be divided at most only a few times. Having shown that ideas are not infinitely divisible, Hume next endeavors to prove that space and time are not infinitely divisible. This is an easy task on the two assumptions which he makes: (1) "Whatever iP. 334. "P. 335. SPACE AND TIME. 91 ideas are adequate representations of objects, the re- lations ... of the ideas are all applicable to the objects"; and (2) "our ideas are adequate representa- tions of the most minute parts of extension. ' '^ There- fore, since ideas are not infinitely divisible, space or extension is not infinitely divisible. The reasoning concerning th.e infinite divisibility of space holds also with respect to that of time.^ The author is now ready to give his derivation of the ideas of space and time. The two subjects may be treated separately. § 16. ;Space.— Hume's doctrine of space and time is very easily misunderstood. Misconception, indeed, rather than interpretation, has been its common lot. A few quotations from expounders will serve as an introduction to the discussion; for the diversity of view among Hume's critics has much justification in the indefinite character of his treatement. Klihne asserts:* "Hume held, with the dogmatic metaphys- icians and most empiricists, space and time to be properties of things." Speckmann,* "Hume starting from empiricism, in his investigations concerning space and time, comes to a similar result as does Kant through his transcendental idealism. Space and time are also for him, in essence, nothing more than subjective forms of intuition of the sensibility." Eitter," "Kant based his standpoint [in mathematics] on a doctrine of space different from that of Locke and Hume." Brede,' "Extension consists, . . . ip. 336. 2 P. 338. ' Veber das Verhaltniss d. Eume'schen u. Kantischen Er- hermtmsstheorie, p. 31. * Ueber B. metaphysische Skepsis, p. 20. ^Kant M. Hume, p. 10. ^Der TJnterschied d. Lehren B., pp. 22, 23. 92 Hume's treatise and inqthet. according to Hume, of a finite number of visible and tangible mathematical points, i. e., of points which have no extension in themselves, . . . but. which, when two of them come together, do not penetrate, but constitute a compound body consisting of parts." Seth,^ "Time and space are, by [Hume's] own show- ing, two different maimers in which perceptions are disposed, and in virtue of which they necessarily lose their character of isolated particulars. . . . They are relations." In accordance with his habitual lack of precision, Hume uses space and extension synonymously, also object and impression.^ He gives the following ac- count of the derivation of the idea of space: "Upon opening my eyes, and turning them to the surround- ing objects, I perceive many visible bodies ; and upon shutting them again, and considering the distance betwixt these bodies, I acquire the idea of extension. ' '* Thus he regards space or extension as a quality of visible bodies, that is, a quality of impressions; and he seems to hold that the idea of extension is distance, or a copy of distance. But distance is a relation, as he himself explained formerly, "because we acquire an idea of it by the comparing of objects."* Hence, true to his philosophical principles, he immediately adds: "My senses convey to me only the impressions of colored points, disposed in a certain manner. If the eye is sensible of any thing farther, I desire it may be pointed out to me. But if it be impossible to shew any thing farther, we may conclude with certainty, that the idea of extension is nothing but 1 Scottish PUl., p. 56. s Of. pp. 341, 345. »P. 340. 4 p. 322. SPACE AND TIME. 93 a copy of these colored points, and of the manner of their appearance."^ Here Hume encounters a diffi- culty. He might have said that the idea of space is distance, or a copy of distance. But now, since he states that the senses convey only the impression of colored points disposed in a certain manner, it fol- lows that the idea of space is a copy of color and its manner of appearance. In short, space or extension is a "compound impression" consisting of "several lesser impressions, that are indivisible to the eye or feeling, and may be called impressions of atoms or corpuscles endowed with color and solidity."* And the idea of space, being but a copy of extension, "con- sists of parts" that are indivisible, and is itself ex- tended.* ' ' The idea of space or extension is nothing but the idea of visible or tangible points distributed in a certain order."* Thus far, Hume has given an account of the de- rivation of only the particular idea of space. He next explains the process of transition to the general idea. When we have had experience of the different colors, and have found "a resemblance in the dis- position of colored points, of which they are composed, we omit the peculiarities of color, as far as possible, and found an abstract idea merely on that disposi- tion of points, or manner of appearance, in which they agree. Nay even when the resemblance is carried beyond the objects of one sense, and the impressions of touch are found to be similar to those of sight ia the disposition of their parts; this does not hinder the abstract idea from representing both, upon ac- 1 P. 341. 2 Of. pp. 345, 346, 366. 3 0f. pp. 344, 523, 527. SPACE AND TIME. 99 merely" that of "the manner or order, in which ob- jects exist. "^ Yet, all general ideas "are really noth- ing but particular ones, considered in a certain light. "^^ But what the critics have failed to notice is, that Hume came remarkably near giving a valid and satisfactory exposition of space and time. True, they have admired the exceedingly ingenious manner in which he presented his argument. Thus if asked, what is space? he replies, "the manner or order in which objects exist." If asked, whence is the idea of space derived? he replies, "from objects of sight or touch 1 ' ' And if asked, what is the idea of space ? he replies, "a copy" of visual or tangible points, or "the disposition" of visual or tangible points, according as the one answer, or the other, suits his purpose; the former answer having reference to the particular idea of space derived logically in accordance with his sys- tem, and the latter having reference to the general idea of space as it prevails in popular thought. The critics, however, have been so busily engaged in de- tecting fallacies, and so intent on observing inconsis- tencies, that they have almost entirely overlooked the really significant points in his doctrine. Hume's exposition of space and time has much more thanr-plausibility to commend it. For the sake of brevity the discussion will be limited to the subject of space, as the argument, with but slight modifica- tions, holds equally with regard to that of time. It is one of the chief distinguishing traits of the philos- opher of NiueweUs that he was the interpreter of actual experience, and not a prophet, nor a seer. That extension is an attribute of visual and tactual 1 P. 346. ^ P. 341. 100 Hume's treatise and inqxjibt. sensations is now a common-place in psychology. Such also was the view of Hume; but in his termi- nology sensations are called impressions.^ It is true, Ward, James, and a few other psychologists maintain that space is an attribute of all sensations. Whether or not this is the case depends entirely upon the definition of the term. Certain it is that extension is an object of sight and touch, that space is an as- pect of the real world of things. And not only was Hume right in holding that space is a datum of sen- suous experience, but he was also right in indicating that there is a fundamental difference between the individual perception of space, and the general notion. In this respect, he had a truer vision than had Im- manuel Kant. His intellectual eye was not dimmed by the mists of German rationalism, nor was his natural force abated by wrestling with noumenal ex- istences. Although in this instance, however, the open minded Scotsman had the truer psychological insight, it must be admitted that his visualizing im- agination and erroneous conception of general ideas misled him with regard to the exact nature of the difference between the particular perception of space, and the general notion. The essential feature of the latter is not the psychological element, but the epis- temological ; and this the author of the philosophy of human nature failed to perceive. For a similar rea- son also Hume's treatment of infiLnite divisibility is palpably defective. The particular idea of space, as he rightly maintained, is not capable of* division to infinity; but the general idea of space, the funda- mental characteristic of which is the element of mean- 1 P. 341. SPACE AND TIME. 101 ing, is without question infinitely divisible. Of like nature, moreover, is Hume's treatment of a vacuum. He was certainly right in insisting that pure or empty space is never an object of perception. For what is ordinarily called the perception of space, the partic- ular idea of space, is really the perception of diffuse matter,, bounded to a greater or less extent by objects of a denser quality.^ On the other, hand, however, he was mistaken when he asserted that the idea of pure space, or of a vacuum is impossible. For by means of abstraction one may have a general idea of space, an idea of pure or empty space, as the possi- bility of movement-sensations, or as the system of space relations— actual or possible— which obtains among external things." 1 Of. Russell, Fowndations of Qeometry, pp. 194, 196. ^Of. Pullerion, PUl. Rev., Vol. X, p. 599; Nichols, The Psychology of Time, pp. 113, 139. CHAPTER VI. KNOWLEDGE— INTUITIVE AHfD DEMONSTRATIVE. § 20. The Faculties of Mind.— The accounts of Hume's theory of knowledge, as presented in both the Treatise and Inquiry, are exceedingly perplexing. This is due, in large measure, to the fact that the epistemological terminology of his day was not ade- quate to the treatment of his subject-matter. At one time he did not properly define his terms ; at another, he did not consistently hold to his definitions. More- over, not having a sufficient number of appropriate terms at his command, he occasionally gave to the same word different, or provisional definitions, ac- cording as the circumstances of the case required, vnthout explaining the relation of these definitions to one another. This is particularly true of the names denoting mental faculties, or sources of knowledge. By faculty he meant, in general, the mind acting in a certain way. Of those which he recognized, the more important are the six following: sensation, memory, imagination, understanding or reason, reflection, and instinct. Sensation, immediately or mediately, is the source of aU knowledge. "When impressions of sense return as ideas, they are called memory, or imagination, ac- cording as they possess— as a general rule,— or do not possess, a certain degree of force and vivacity, and a certain measure of fixity of order. "When the ideas of imagination— or of memory— lose, to a certaia ex- 102 KNOWLEDGE, INTUITIVE AND DEMONSTRATIVE. 103 r tent, their sense content, and are combined in new forms by means of comparison, abstraction, or gen- eralization, they become transformed into conceptions, and are attributed to the understanding or reason. Thus imagination and reason, like imagination and memory, differ only in degree. As Hume said,^ the understanding or reason is but "the general or more established properties of the imagination." Hence, memory, imagination, and reason are different stages of one and the same process.^ Reflection sometimes accompanies, sometimes follows sensation, memory, imagination, and reason. It is in part the basis of instinct. Instinct is an indispensable factor in the philosophy of human nature. Of amorphous character, it plays many parts. It corresponds somewhat with the ele- ment of feeling in perceptions; it is a sentiment, or manner of conception. It is also closely related to sensation. "It seems evident," says Hume,' "that men are carried, by a natural instinct or preposses- sion, to repose faith in their senses." Moreover, in- stinct includes, to a greater or less extent, imagination, belief, habit, custom, and experiential or moral rea- soning. "All belief of matter of fact or real exist- ence," Hume affirms, in the Inquiry,* "is derived merely from some object, present to the memory or senses, and a customary conjunction between that and some other object. . . . This belief is the necessary II, p. 547; of. IV, p. 38 n. ' Of. Gore, The Imagination in Spinoea and Hume, p. 74. — " Keason is the imagination generalized, and the imagination is reason particularized." »IV, p. 124; cf. I, pp. 483, 548. 4 P. 40; of. I, pp. 403, 474, 475. 104 HUME'S TREATISE AND INQUIET. result of placing the mind ia such circiunstances. It is an operation of the soiil, when we are so situated, as unavoidable as to feel the passion of love, when we receive benefits: or hatred, when we meet with in- juries. AU these operations are a species of natural instincts, which no reasoning or process of the thought and understaading is able, either to produce, or to prevent." Again,^ "Nothing leads to this inference [based on the idea of cause and effect] but custom or a certain instinct of our nature. ' ' And in the Treatise he asserts:^ "Season [experiential reasoning] is noth- ing but a wonderful and unintelligible instinct in our, souls, which carries us along a certain traia of ideas, and endows them with particular qualities, according to their particular situations and relations. . . . Nature may certainly produce whatever can arise from habit : Nay, habit is nothing but one of the prin- ciples of nature, and derives aU its force from that origin." Furthermore, instinct is a species of knowl- edge derived from "the original hand of nature," and which is capable of little or no advancement* Finally, it may be regarded aS including what are commonly called the ideals of reason,— goodness, beauty, truth, duty, etc. ' ' There is a great difference, ' ' says Hume,* "betwixt such opinions as we form after a cahn and profound reflection, and such as we embrace by a kind of instinct or natural impulse, on account of their suitableness and conformity to the mind. ' ' Naturally, therefore, instinct is superior to reason. It is the great guide of human life. iP. 131. 2 P. 471 5 c/=. pp. 387, 404. a IV, p. 88; cf. I, pp. 470, 471. a, p. 501; of. pp. 474, 475, 478, 548, 649. KNOWLEDGE, INTUITIVE AND DEMONSTKATIVE. 105 For the sake of clearness, it is well to note that, in the Inquiry, Hume made less iise of imagination, and more use of instinct, than he did in the Treatise. Many mental processes which, in the earlier work, were attributed to imagination are, in the later, as- cribed to instinct, custom, or nature. This change of treatment, although it does not indicate any change of doctrine, seems to imply a truer appreciation of the function of iostinct. Yet it does not necessarily imply even this much. At most, it only rendered explicit in the Inquiry, what was implicit in the Treatise. For instinct, custom, or habit is always the basis or ground of the transition of imagination. The full significance of the change it is probably impos- sible to determine; for Hume used instinct, custom, habit, and imagination more or less interchangeably in both works. In the Treatise he asserted:^ "When I consider the influence of this constant conjunction, I perceive, that such a relation can never be an object of reasoning, and can never operate upon the mind, but by means of custom, which determines the imag- ination to make a transition from the idea of one object to that of its usual attendant, and from the impression of one to a more lively idea of the other. ' ' Again," "Eeason [experiential reasoning] is nothing but a wonderful and unintelligible instinct in our souls, which carries us along a certain train of ideas, and endows them with particular qualities, according to their particular situations and relations. ' ' ■ That is, reasoning is regarded equally as a transition of the imagination, and as a wonderiul and unintelligible instinct. Likewise, in the Inquiry, the author stated :^ I P. 464; of. p. 487. J P. 471. > P. 62 ; c/=. p. 65. 106 Hume's treatise and inquiey. "After a repetition of similar instances, the mind is carried by habit, upon the appearance of one eyent, to expect its usual attendant, and to believe that it wiU exist. This connection, therefore, which we feel in the mind, this customary transition of the imagina- tion from one object to its usual attendant, is the sen- timent or impression from which we form the idea of power or necessary connection." Further,^ "We have no argument to convince us, that objects, which have, in our experience, been frequently conjoined, will likewise, in other instances, be conjoined in the same manner; and . . . nothing leads us to this inference but custom or a certain instinct of our nature." "Provided we agree about the thing," Hume once said, "it is needless to dispute about the terms. ' ' Acctfrdiugly, in the briefer work, instead of attributing certain mental processes directly to imag- ination, as formerly, and then indirectly to custom or instinct, he often ascribed them to custom, instinct, or nature directly. § 21. Intuitive Knowledge. — In the philosophy of human nature, impressions and ideas are the ultimate elements of knowledge. These possess certain qualities which constitute the ground of the three natural rela- tions. Natural relations are the source of the seven kinds of philosophical relations, also of modes and substances. And the philosophical relations ate the basis of the different degrees of certainty. In Part III of the Treatise, Hume deals with this last problem under the title "Knowledge and Probability." As has already been stated,^ he distinguishes tjfo classes of philosophical relations : those that depend entirely iP. 130; cf. p. 40. a p. 83. KNOWLEDGE, INTUITIVE AND DEMONSTEATIVB, 107 upon the ideas compared, and those that may be changed without any change in the ideas. The former class-relations of resemblance, contrariety, degrees of quality, and proportions in number and quantity— constitute "the foundation of science," and are objects of knowledge and certainty. The latter- identity, contiguity, and causation,— are the ground of probability.^ Knowledge is of two Mnds, intuitive, and demonstrative; and probability also is of two kinds, proofs, and probability in a narrower sense.'' Proofs and probability will be treated in the three following chapters. Intuitive knowledge means sense and memory knowledge. It is based on the relations of resem- blance, contrariety, and degrees of quality. It arises immediately from the observation, or comparison of impressions and ideas. It does not necessarily mean exact, nor certain knowledge, but only that Mnd of knowledge which the mind obtains "at first sight," or which it arrives at, immediately on the perception, among impressions and ideas, of the relations of re- semblance, contrariety, or degrees of quality. Thus, in the Treatise, Hume asserts:' "And though it be impossible to judge exactly of the degrees of any quality, such as color, taste, heat, cold, when the dif- ference betwixt them is very small; yet it is easy to decide, that any of them is superior or inferior to another, when their difference is considerable. And this decision we always pronounce at first sight, with- out any inquiry or reasoning." There i^ no specific treatment of intuitive knowl- edge in the l^ter work. In the earlier, Hume, follow- iPp. 372, 373. 2 P. 423. »P. 373. 108 Hume's teeatise and inquiet. ing Locke, regarded Imowledge as the perception of the Eigreement or disagreement of impressions and ideas; consequently, he considered the philosophical relations as the ground or possibility of reasoning. But in the Inquiry, he omitted the table of philosoph- ical relations, and for the classification of knowledge, or complex ideas, into relations, modes, and sub- stances, he substituted the twofold division of "all the objects of human reason or inquiry," viz., rela- tions of ideas, and matters of fact ;^ relations of ideas corj-esponding to those philosophical relations that depend entirely upon the ideas compared, and matters of fact corresponding, in large measure, to those phi- losophical relations that may change while the ideas compared remain the same. Accordingly, under the former division he includes the sciences of arithmetic, algebra, and geometry, and in short, every affirmation which is either "intuitively or demonstratively cer- tain," and under the latter, the natural and historical sciences of probability.^ In Book III of the Treatise of Human Nature^ Hume reasserted the position of Book I, that resemblance, contrariety, degrees' of quality, and proportions in number and quantity are the only relations which are "susceptible of certainty and demonstration." Although in the Inquiry* he thought that "the sciences of quantity and number" might be pronounced "the only proper objects of knowledge and demonstration," there is no reason to suppose that his view of intuitive knowledge was dif- ferent from that presented in the Treatise. He im- plies the same distinction as formerly between intui- ' P- 20. ! Pp. 20, 22, 135. » II, pp. 240, 241. « P. 134, KNOWLEDGE, rNTXHTIVE AND DEMONSTRATIVE. 109 tive and demonstrative knowledge, when lie says that "the connection" between propositions is not "intui- tive," if it "requires a medima."^ It may be imagined, perhaps, that there is some special significance in the substitution, in the later work, of the twofold division of knowledge— relations of ideas, and matters of fact— for the threefold divi- sion of the products of the laws of association, and for the subdivision of philosophical relations. Such, however, does not seem to be the case. Hume wrote the Treatise with Locke often in mind. But although he foUowed his master in some reduplications, cross- divisions, and contradictions, he endeavored to im- prove upon Locke's celebrated Essay. Ideas of sensa- tion and reflection, as the original elements of knowl- edge, he transformed into impressions and ideas of sensation and reflection. While he accepted Locke's definition of knowledge, and his classification of com- plex ideas ; instead of the four kinds of agreement and disagreement between ideas, as the necessary condition of knowledge, he put forward the seven kinds of phi- losophical relations. The two tables are related as follows : 1. Identity and diversity. 1, 2, 3. Identity, resemblance, and contrariety. 2. Relation. 4, 5, 6. Contiguity or relations of time and place, degrees of quality, and propor- tions in number and quantity. 3. Co-existence. - 7. Cause and effect. 4. Real-existence. It will be observed that Hume's classification of 1 P. 30. 110 " humb's treatise and inquiet, philosophical relations differs considerably from Locke's four kinds of agreement or disagreement between ideas; for not only has the author of the Treatise naturally no place for knowledge of sub- stance or real-existence, but his relations of identity and contrariety have not the same meaning as Locke's agreement or disagreement in the way of identity and diversity. As Hume developed his system of philosophy, he worked gradually farther away from Locke's theory of knowledge, and approached, in certain respects, the position of Butler.^ Soon he adopted relations of ideas and matters of fact as a convenient classifica- tion of the objects of knowledge. It is one of Pat- ten's^ many misconceptions that this classification first appeared in the Inquiry. On the contrary, it developed step by step with the natural progress of the author's thought, as he proceeded from the con- sideration of theoretical philosophy to that of prac- tical. In some passages of the Treatise, for example, it is hinted at, or implied.' In Book II of the Treatise of Human Nature it is, for the first time, explicitly stated. "Truth is of two kinds," says Hume,* "con- sisting either in the discovery of the proportions of ideas, considered as such, or in the conformity of our ideas of objects to their real existence." And in Book III of the Treatise of Human Nature it is 'fre- quently employed, as in the following passage :° "As the operations of human understanding divide them- 1 Of. Analogy, p. 3. 2 The Development of English Thought, p. 225. » Gf. pp. 394, 395, 483. »n, p. 223 J of. p. 227. 611, p. 240; cf. p. 236. , : - KNTOWLEDGE, INTUITIVE AND DEMONSTRATIVE. Ill selves into two kinds, the comparing of ideas, and the iaf erring of matter of fact; were virtue discovered by the -understanding ; it must be an object of one of these operations, nor is there any third operation of the understanding, which can discover it." The im- possibility of giving a popular exposition of philo- sophical relations, or a satisfactory treatment within a limited compass was probably the chief cause for the introduction in their stead, in the Inquiry, of the simple division of objects of knowledge into relations of ideas and matters of fact.^ § 22. Demonstrative Knowledge. — Demonstrative knowledge is that which arises from the imderstand- ing or reason. It is based on the relations of num- ber and quantity. Very simple relations of number or quantity, such as may be observed at "one view," are more properly intuitive knowledge. But when these relations can be perceived only by means of "a chain of reasoning," they constitute demonstrative knowledge.^ The sciences of demonstration are arith- metic, algebra, and geometry. Hume's doctrine of mathematics has always been one of the interesting puzzles in his philosophy. It has been a subject of universal contention, and many expositions— as well as criticisms— of it have been given. These, however, at most have been but par- tially correct, and have resulted rather in contradic- tion and confusion, than in conviction or illumination. A few quotations, while exhibiting the variety of in- terpretation on the question, may suggest some guid- ing thoughts for a new solution. Masaryk asserts:' iCf. pp. 80-83, above. ' Pp. 373, 374. ' D. H. Skepsis u. d. Wahrsohemliohkeitsrechmmg, p. 6 ; cf. Windelband, Oesoh. d. n. PMl, I, pp. 321, 327; Rosenkranz, 112 ' humb's treatise and inqtjirt. "According to Hume, mathematics is an absolutely- certain science, because founded on a priori prin- ciples." Watson,^ "The mathematical doctrine of Hume may be stated in these three propositions: (1) Mathematical judgments rest upon impressions of sense; (2) they are singular; (3) they are only ap- proximately true." Spicker,^ "We must here note, attentively that Hume, equally with Kant, considers mathematics as a pure activity of thought, which takes place independently of all experience, and is, therefore, a priori certain." Stuckenberg,* "Mathe- matics, which Hume considered as a relation of ideas, is grounded by him also exclusively on experience." Petzholtz,* "Mathematics belongs to the sciences which treat of relations of ideas, whose propositions, there- fore, we discover through the pure activity of thought. . . . "While Hume allows to arithmetic this uncon- ditioned certainty, he does not attribute such without reserve to geometry." Caird,® "Hume in his earlier treatise attempted ... to trace back the ideas of mathematics to impressions of space and time: but the attempt led him to the denial of the objective validity of mathematical truth, in so far as it goes beyond the possibility of empirical measurement." Gesch. d. Kantischen Phil., p. 23; Volkelt, ErfaJirung u. Denken, p. 108; tlhl, 3. Stellv/ng m d, engUschen PMl., pp. 31, 32; Eitter, Eant u. Hume, pp. 7, 9. ^An Outline of Philosophy, p. 357. ^ Kant, Hume w. Berkeley, pp. 110, 117, 125; cf. Gordy, Hume as Seeptio, p. 1. ' Orundprolleme in Hume, p. 18; cf. I, pp. 222, 223. * Die Hauptpunlcte D. H. Brhenntnislehre, p. 29 ; cf. Adam- son, Ency, Brit., art. Hume, p." 353. ^The Critical Philosophy of I. K., I, p. 256; ef. MahaflEy and Bernard, Kant's Critical Philosophy, II, p. 23, and n. KNOWLEDGE, INTUITIVE AND DEMONSTEATIVB. 113 Webb/ "As to Hume's opinion with reference to the a priori character of mathematics, there can be no intelligent diversity of opinion. . . . He abandoned the doctrine of the Treatise. ' ' Riehl,^ " It is erroneous to assert, that Hume has not doubted the validity of pure mathematics, since he, in the Treatise (and even in the Inquiry), not only doubts but positively im- pugns the evidence for geometry, and restricts validity to the abstract part of mathematics, the pure doctrine of quantity." Statements similar to these might be quoted indefinitely. They indicate great diversity in the answers given to the four following questions: (1) Is mathematics, according to Hume an a priori science? (2) Is it an absolutely certain science? (3) Is it a perfectly exact science? (4) Is there any difference between the respective positions of the Treatise and Inquiry on the three preceding ques- tions ? These quotations also indicate that the ground of their diversity is not solely subjective differences in the vsriters. The solution of the problem is to be sought only in a study of the objective differences that exist in Hume's treatment. And the key to this solu- tion is the discernment that Hume, in the Treatise, gave three different, although not distinct or separate accounts of mathematics, corresponding to three stages of development in his doctrine. These accounts may be called the epistemological, the logical, and the psy- chological. They will be treated in their order. I. The Epistemological Treatment of Mathematics. > Veil of Isis, pp. 101, 102; of. Long, Ueler Hume's Lehre V. d. Ideen u. d. Substane, p. 35. ! Der pMlosopMsche Kriticismus, I, pp. 69, 96, 97 ; of. Windelband, Hist, of Phil., p. 473; Brede, Der UnterscMed d. Lehren H., pp. 11, 35. 114 Hume's treatise and inquibt. —Hume's first aecoimt of his doctrine of mathematics is given in Parts II and III. The mathematical sci- ences, as already stated, are based on the philosophical relations of number and quantity. These relations, in turn, are based on certain qualities of impressions and ideas.^ Geometrical relations are modes of space. Arithmetical and algebraic relations are modes of number. Both space and number are constituted of simple and indivisible imits. The units of space are mathematical points, "endowed with color" or "solidity."" But of the units of number no explana- tion is offered. Hume merely asserts that "the unity, which can exist alone, and whose existence is neces- sary to that of all number, . . . must be perfectly indivisible and incapable of being resolved into any lesser unity. ' '* The idea of space is derived from the senses of sight and touch.* And the idea of number arises from the perception of objects.^ It is manifest, therefore, that aU the mathematical sciences are em- pirical. Arithmetic and algebra Hume regards as perfectly exact and certain sciences, because in dealing with numbers, the subject-matter of these sciences, "we are possessed of a precise standard, by which we can judge of [their] equality and proportion; and accord- ing as they correspond or not to that standard, we determine their relations, without any possibility of error."* Geometry, on the other hand, he declares "falls short of that perfect precision and certainty, which are peculiar to arithmetic and algebra, . . . because its fundamental principles are derived merely 1 Of. pp. 322, 323, 372. a Pp. 345, 347. 'P. 338. «Pp. 340, 341. spp. 337, 338. « P. 374. KNOWLEDGE, INTUITIVB AND DBMONSTEATIVE. 115 from appearances. ' '^ That is to say, geometry would be a perfectly exact and certain science, if its funda- mental principles, the definitions and axioms on which it is founded, were perfectly exact and certain. But these definitions and axioms are derived merely from the appearances of objects, and consequently, are not exact. Hence, the science of geometry is neither per- fectly exact nor certain. Yet geometry excels in ex- actness and certainty "the imperfect judgments of our senses and imagination." For although Hume admits that the judgments concerning geometrical relations are not "more exempt from doubt and error than those on any other subject,'"' he maintains, at the same time, that the fundamental principles of geometry "depend on the easiest and least deceitful appearances," and therefore, "bestow on their con- sequences a degr,ee of exactness, of which these con- sequences are singly incapable. ' '° Apparently inconsistent with the preceding account is a passage in which Hume asserts that "geometry fails of evidence" in one "single point" — its demon- strations for the infinite divisibility of extension,— but that "aU. its other reasonings command our fullest assent and approbation."* This latter statement, if taken literally, cannot be harmonized with Hume's general position. But the author undoubtedly meant that it should be understood only in a relative sense. For he repeatedly affirms that geometry is not an exact nor certain science like arithmetic or algebra, its first principles having been derived from the general appearances of objects.^ 1 P. 374. - 8 P. 353. 3 P. 374. « P. 357. 6 Pp. 350, 353, 354, 355. 116 Hume's treatise and inquiey. It may be noted, however, that if geometry dealt with discrete quantity, like numbers, instead of with continuous quantity, as is space, it would, according to Hume, be a perfectly exact and certain science.^ Arithmetic and algebra are such, because they deal with discrete quantity. They possess a perfect exact- ness and certainty, because the exact difference be- tween any two numbers whatever can easily be de- termined. The author speaks of two standards of certainty in geometry, one accurate, the other inac- curate. The inaccurate standard is the indefinite presentations of the senses and imagination, "derived from a comparison of objects, upon their general ap- pearance, corrected by measuring and juxta-position. ' ' The accurate standard is the indivisible points of which lines and other geometrical figures are com- posed.'' But although this latter standard is theo- retically exact, it is impracticable both in science and in common life. If mathematicians be asked what they mean when they say that one line or surface is equal to, greater, or less than another, " [those] who defend the hypothesis of indivisible points," Hume asserts,' "need only reply, that lines or surfaces are equal, when the numbers of points in each are equal ; and that as the proportion of the numbers varies, the proportion of the lines and surfaces is also varied. But though this answer be just," he continues, "as weU as obvious ; yet I may afarm, that this standard of equality is entirely useless, and that it never is from such a comparison we determine objects to be equal or unequal with respect to each other." On the question of the exactness and certainty of geom- 1 Pp. 351, 374. i Pp. 351, 357. » P. 351. KNOWLEDGE, INTUITIVB AND DEMONSTRATIVE, 117 etry, he explicitly states Ms position as follows:^ "It appears, then, that the ideas which are most essential to geometry, viz., those of equality and inequality, of a right line and a plain surface, are far from being exact and determinate, according to our common method of conceiving them. ... As the ultimate standard of these figures is derived from nothing but the senses and imagination, it is absurd to talk of any perfection beyond what these faculties can judge of; since the true perfection of any thing consists in its conformity to its standard." The results of the discussion thus far may here be summarized. Proportions in number and quantity are the ground of demonstrative knowledge. But these proportions, like the other philosophical rela- tions, are derived by means of the senses. Con- sequently, mathematics is an empirical science. Arithmetic and algebra are perfectly exact and cer- tain sciences, since, dealing vdth discrete quantity, they possess a perfectly exact standard. But geom- etry, although it excels in exactness and certainty the inaccurate judgments of the senses or imagination, falls short of perfect precision, because dealing with continuous quantity, it lacks a perfectly exact stand- ard. This may be called Hume's epistemological treatment of mathematics. It is only one part of his doctrine, and is considerably modified later. II, The Logical Treatment of Mathematics.— In Part IV, the author, draws the logical consequences of his philosophical principles, and sums up his doc- trine of the understanding. In the first section he treats of mathematics in the following manner:^ "In 1 P. 356; cf. pp. 348, 350, 353, 355. sp. 472. 118 HUME'S TREATISE AND INQUIET. all demonstrative sciences tlie rules are certain and infallible; but when we apply tbem, our fallible and uncertain faculties are very apt to depart from them, and fall into error. "We must, therefore, in every reasoning form a new judgment, as a check or control on our first judgment or belief ; and must enlarge our view to comprehend a kind of history of all the in- stances, wherein our understanding has deceived us, compared with those, wherein its testimony was just and true. ... By this means all knowledge degen- erates into probability. . . . There is no algebraist nor mathematician so expert in his science, as to place entire confidence in any truth immediately on his discovery of it, or regard it as any thing, but a mere probability. ... In accounts of any length or im- portance, merchants seldom trust to the infallible certainty of numbers for their security." And as no one wiU maintain "that our assurance in a long enumeration exceeds probability," Hume thinks he may "safely affirm, that there scarce is any proposi- tion concerning numbers, of which we can have a fuller security." If "any single addition were cer- tain, every one would be so, and consequently the whole or total sum. ' ' But of course the whole is not certain. "Since, therefore," he concludes,^ "aU knowledge resolves itself into probability, and be- comes at last of the same nature with that evidence which we employ in common life, we must now ex- amine this latter species of reasoning, and see on what foundation it stands." In every judgment concerning probability, and con- sequently concerning knowledge— since "all knowl- 1 P. 473. KNOWLEDGE, INTUITIVE AND DEMONSTRATIVE. 119 edge resolves itself into probability," — there are, according to Hume, two sources of error and un- certainty, the understanding which judges, and the object about which the judgment is made.^ Hence, even "the man of the best sense and longest experi- ence . . . [is] conscious of many errors in the past, and must still dread tho like for the future." Hume contends that, because of this natural fallibility of the understanding, every judgment requires to be corrected by another judgment, this one by another and so on ad infinitum. Thus as "demonstration is subject to the control of probability," so is "proba- bility liable to a new correction by a reflex act of the mind, wherein the nature of our understanding, and our reasoning from the first probability become our objects." And he concludes agaiu:^ "When I reflect on the natural fallibility 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 scrutiny 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 logical account in Hume's treatment of mathematics, — or rather one might say of knowledge. For it has doubtless been noticed that, in following his order of exposition, the subject has been gradually broadened, until now the account applies not merely to mathematics but to knowledge in general. The foregoing passages have given rise to two dif- ferent lines of interpretation, neither of which is quite correct. According to the one, Hume distinguished ' P. 474. « Ibid.; cf. p. 475. 120 Hume's treatise and estquirt, between mathematics as a pure science and mathe- matics as an applied science, and maintained that the former possesses exact and demonstrative certainty, but the latter only probability. Accoi^ding to the other interpretation, Hume's doctrine of mathematics is the culmination of a system of absolute skepticism or nihilism. The former view prevails, to a consid- erable extent, among the German critics ; the latter is not uncommon with the writers of the Scottish school. They may be examined in succession. Windelband afSrms:^ "Mathematics is . . . the sole demonstrative science; and is that just because it relates to nothing else than the possible relations between contents of ideas, and asserts nothing what- ever as to any relation of these to a real world. In this way the terministic principle of Hobbes is in complete control with Hume, but the latter proceeds still more consistently with his limitation of this theory to pure mathematics." And Eiehl asserts:^ "Hume doubts not the exactness of pure, but the validity of applied mathematics." This position has been controverted by Adamson. "No question," he declares,* "arises regarding the existence of the fact represented by the ideas, and in so far, at least, mathe- matical judgments may be regarded as hypothetical. . . . That the propositions are hypothetical in this fashion does not imply any distinction between the abstract truth of the ideal judgments and the imper- fect correspondence of concrete material with these ^ History of PUlosophy, p. 473; cf. Petzholtz, Die Haupt- punkte D. E. Erlcenntnislehre, p. 29. 2 Der pMlosophische Kriticismus, I, pp. 96, 97. »Enoy. Brit., art. Sume, p. 353. KNOWLEDGE, INTUITIVE AND DEMONSTEATlVE. 121 ideal relations. Such distinction is qtiite foreign to Hume, and can only be ascribed to Mm from an entire misconception of bis view regarding tbe ideas of space and time." Tbe statement of Adamson is tbe more correct one. Not only does Hume fail to distinguisb between "the abstract trutb of tbe ideal judgments and tbe imperfect corr,espondence of concrete material with tbese ideal relations, ' ' but be denies tbat tbis dis- tinction exists. "[To reason]," be says,^ "tbat tbe objects of geometry, . , . are mere ideas in tbe mind ; and not only never did, but never can exist in nature, ' ' is ' ' absurd and contradictory. ' ' Again,* ' ' The notion of any correction [in geometry] beyond what we have instruments and art to make, is a mere fiction of tbe mind, and useless as well as incomprehensible." Finally, he states conclusively:* "It is usual with ma,thematicians, to pretend, that those ideas, which are their objects, are of so refined and spiritual a nature, tbat they f aU not under tbe conception of the fancy, but must be comprehended by a pure and in- tellectual view, of which the superior faculties of the soul are alone capable. . . . But to destroy tbis arti- fice, we need but reflect on that principle so often insisted on, that all our ideas are copied from our impressions." At the same time, it should be ob- served that, somewhat in accordance with tbe view expressed by "Windelband and Biebl, Hume recog- nized a distinction between arithmetic and algebra as exact and certain sciences, and tbe practical applica- tion of these sciences to concrete material. He re- peatedly asserted that arithmetic and algebra are perfectly exact and certain,* but that in practice "all : P. 348. « P. 353. ' P. 3751 * Pp. 374, 472. 122 HUME'S TREATISE AND INQUIET. knowledge degenerates into probability."^ Further- more, he said:^ "In aU demonstrative sciences the rules are certain and infallible; but when we apply them, our fallible and uncertain faculties are very apt to depart from them, and f aU into error. ' ' Controversy on this subject has arisen owing to the fact that Hume neglected to give a derivation of num- ber. Adamson, following in the wake of Green, in- sists that, on Hume's fundamental principles, a de- rivation of number suitable to serve as a foundation for mathematics cannot be given. While on the other hand, Windelband, recognizing that Hume held arith- metic and algebra to be perfectly exact and certain sciences, erroneously concludes that mathematics is a pure science. The truth of the matter seems to be this : not only is a derivation of abstract number pos- sible, in accordance with the principles of empiricism, but so also is a derivation of abstract quantity. For by means of approximations, abstraction, and gen- eralization, the transition is not difficult from the perception of real lines and circles in nature to the ideas of perfectly straight lines and perfect circles corresponding to the definitions of geometry. Hume, neglecting to give a derivation of number, failed to show how arithmetic and algebra, as abstract sciences, are possible. Nevertheless, he rightly held that arith- metic and algebra are perfectly exact and certain. And he not only failed to give a derivation of quan- tity—pure or abstract quantity,— but contended that such could not be given, and hence mistakenly asserted that geometry is not an exact nor certain science. The position of many writers of the Scottish school, 1 Pp. 472, 473. 2 p. 472. KNOWLEDGE, INTUITIVB AND DEMONSTBATIVB. 123 that Hume's theory of knowledge is a system of abso- lute skepticism, is of course unwarranted. True, in so far as they assert that absolute skepticism is the result of the strictly logical, as distinguished from the psychological factor in this theory of knowledge, they are literally correct. The author admits this himself. "When I proceed still farther," he says,^ "to turn the scrutiny 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. ' ' But Hume clearly perceived that the human mind did nOt always function in con- formity with the laws of logic. Then followed natur- ally his psychological account of mathematics,— or rather, it may be said, of knowledge in general. III. The Psychological Treatment of Mathematics. —The psychological element is a most important fac- tor in Hume's theory of knowledge. It is the great head stone of the comer. It is not only an original, but a distinctively Anglo-Saxon contribution to phi- losophy. Pfleiderer has well said that "imagination and association are two genuine English powers, through which this people, on the ideal ground of poetry and in the magnificent arena of achievement, have brilliantly paid their tribute to the world's his- tory." Another tribute has similarly been paid in the subtle realm of speculative thought. After stating that the logical result of his episte- mologieal account of knowledge is a total extinction of belief and evidence, Hume proceeds:^ "Should it here be asked me, whether I sincerely assent to this argument, which I seem to take such pains to ineul- » Pp. 474, 475. ' P. 474. 124 Hume's treatise and inqxtiky. cate, and whether I be really one of those skeptics, who hold that all is uncertain, and that our judgment is not in any thing possessed of any measure of truth and falsehood; I should reply, that this question is entirely superfluous, and that neither I, nor any other person was ever sincerely and constantly of that opin- ion. Nature, by an absolute and Tincontrollable neces- sity has determined us to judge as well as to breathe and feel." This determination of nature arises from custom or habit. From custom arises belief. And belief alone preserves the mind from total skepticism.^ But all demonstrative knowledge— arithmetic and al- gebra as well as geometry — is reduced to a species of probability. In short, the greatest degree of certainty, whether intuitive or demonstrative, is belief. "Belief is more properly an act of the sensitive, than of the cogitative part of our natures,"^ and the degree of conviction attending it — although at times the con- viction is delusive'— "is sufficient for our purpose, either in philosophy or common life."* IV. Conclusion.— The answers of the Treatise to the first three questions that demand settlement have now been indicated. The answer to the first, is an unqualified negative. Mathematics is not an a priori science, but empirical, because its first principles are sensible. The answer to the second question is a qualified negative. Is mathematics an absolutely cer- tain science? It depends upon the meaning attrib- uted to absolute. Mathematics is not an absolutely certain science, in the sense of being a priori certain. For the human mind is finite ; knowledge is relative ; and in nearly all thinking processes there is a possi- ' P. 475. 2 Ibid. 3 Of. pp. 545, 547. * P. 476. KNOWLEDGE, rNTUITIVB AND DBMONSTEATIVE, 125 bility of error. But arithmetic and algebra are em- pirically certain. Geometry, of course, is not. In certain passages, however, it is said that arithmetic and algebra are perfectly exact and certain sciences.^ Yes, those statements are in the epistemological ac- count, and are to be understood, therefore, in a pro- visional or relative sense. In the psychological ac- count, Hume holds that these sciences are practically, or empirically certain, not absolutely or a priori cer- tain. The answer to the third question is a divided one. Arithmetic and algebra are perfectly exact sci- ences ; on the other hand, geometry is not. § 23. Treatment of Mathematics in the Appendix. — In the appendix Hume added a few remarks on geometry, for the purpose of further explaining his meaning. These passages do not indicate any change of view from that expressed in the Treatise, and con- sequently, do not require extended comment. There is but one statement that seems to call for a word of explanation. "If [mathematicians] employ," says the author,* "as is usual, the inaccurate standard, derived from a comparison of objects, upon their gen- eral appearance, corrected by measuring and juxta- position; their first principles, though certain and infallible, are too coarse to afford any such subtile inferences as they commonly draw from them. ' ' Here he speaks of the first principles of geometry as being "certain and infallible," whereas, in the Treatise he had regarded them as being inexact, and not precisely true.' The inconsistency is only verbal. In the ap- pendix he does not mean, literally, that the first prin- 1 P. 374. 2 P. 357. s Of. pp. 350, 356, 373, 374. 126 hxtme's treatise and inquiry. ciples of geometry are "certain and infallible," for he not only says that they are "too coarse" to afford such "subtile inferences" as are commonly drawn frflm them, but he immediately adds that they "are founded on the imagination and senses." And in another passage he asserts^ "that the only useful no- tion of equality, or inequality, is derived from the whole united appearance and the comparison of par- ticular objects." § 24. Treatment of Mathematics in the Inquiry. — In the Inquiry, on the subject of mathematics, there is at once observable a great difference in the form of statement. Since Hume omits that portion of the Treatise which deals with space and time, and conse- quently neglects to give a derivation of space, as he did formerly to give a derivation of number, the sci- ences of arithmetic, algebra, and geometry seem to stand upon the same basis of exactness and certainty ; and since he omits the account of philosophical rela- tions, the former distinctions between the different degrees of evidence not only fall into the background, but almost entirely disappear. The obvious result is that the author appears to have approached, if not to K have adopted, the common sense view of mathematics...^ i He divides "all the objects of human reason or in- I quiry" into relations of ideas and matters of fact; 5 and under relations of ideas he includes the sciences ; of arithmetic, algebra, and geometry, "and in short, \, every affirmation, which is either intuitively or demon- Utratively certain."' The propositions of mathe- iP. 352. ' Of. pp. 107, 108, above. »P. 20; of. p. 22, 135. KNOWLEDGE; nSTTUITITE AND DEMONSTEATIVE. 127 matics, he holds, "are discoverable by the mere opera- tion of thought, without dependence upon what is any- where existent in the universe. Though there never were a circle or triangle in nature, the truths, demon- strated by Euclid, would for ever retain their cer- tainty and evidence."^ The foregoing statement summarizes Hume 's treat- ment of mathematics in the Inquiry. It corresponds to the epistemological account in the Treatise. Both the logical and psychological accounts are omitted in the later work. Naturally, therefore, it has been al- most universally supposed that there is a fundamental difference between the doctrine of mathematics in the Inquiry and that in the Treatise. The supposition, however, is without foundation. Had the logical and psychological accounts not been omitted, it is prac- tically certain that the position of both works, on this question, would have been identical. But why are these accounts omitted? it may be asked; does not this fact in itself indicate a change of view? Not neces- sarily, for Hume was here giving a popular exposition of the more easy and interesting parts of his system, and he reserved mathematics for special treatment on another occasion. Later, he wrote an essay on "The Metaphysical Principles of Geometry," but did not publish it, because Lord Stanhope convinced him that "either there was some defect in the argument, or in its perspicuity. ' '^ Even in default of this essay, there are several incidental references in the Inquiry which go far to prove that his view of mathematics is still essentially the same as that presented in the Treatise. 1 P. 22; cf. pp. 10 n., 28, 37, 50, 51, 134. 2 Gf. pp. 96, 97, above. 128 Hume's treatise and inquiry. Arithmetic, algebra, and geometry are not a priori sciences, but empirical. For Hume, in accordance with his principle that all ideas are copies of impres- sions, states explicitly that "the ideas of the mathe- matical sciences, being sensible, ' ' are always clear and determinate.^ ' ' All the ideas of quantity, ' ' he thinks,^ "upon which mathematicians reason, are nothing but particular, and such as are suggested by the senses and imagination." Since, therefore, the mathemat- ical sciences are empirical, they are not absolutely or a priori certain. "One may safely, . . . affirm," says Hume/ "that if we consider, [the moral and mathematical sciences] in a perfect light, their ad- vantages and disadvantages nearly compensate each other, and reduce both of them to a state of equality." The general view just indicated will be confirmed by a special consideration of geometry,— that branch of mathematics being treated somewhat more fuUy than is arithmetic or algebra. It has already been shown* that although Hume, in the Inquiry, omitted the treatment of space and time, yet his doctrine of space and time is similar in both works. It is not surprising, therefore, that he looks upon geometry as an empirical science. His position, as stated in section iv, corresponds with that of Hobbes. His meaning is, that "the truths" dem- onstrated by Euclid "for ever retain their certainty and evidence," after knowledge of the geometrical figures has once been acquired. Since, however, aU geometrical figures are sensible, a knowledge of them is derived only through sense experience. In short, geometry in an inductive science. But it differs from iP. 50. 2 P. 129 n. >P. 50. *Pp. 95-97. KNOWLEDGE, INTUITIVE AND DEMONSTRATIVE. 129 other inductive sciences in tlie fact that one instance serves as a sufficient basis for a generalization. ' ' The conclusions, which [reason] draws from considering one circle, are the same which it would form upon surveying all the circles in the universe. ' '^ Kant, it is true, mistakenly supposed Hume to regard geom- etry — or rather mathematics— as an analytical science. For this opinion, indeed, Hume gave some ground when he affirmed that the equality of the square on the hypothenuse of a right angled triangle to the squares on the two sides was a relation, "discoverable by the mere operation of thought. ' ' But he explained his meaning when he declared that this relation could not "be known, let the terms be ever so exactly de- fined, without a train of reasoning and inquiry."^ Not only is geometry, as treated in the later work, an empirical science, but it is not a perfectly exact science. In the editions of 1748 and 1751, in a note appended to the twelfth section, Hume asserts:* "In general, we may pronounce, that the ideas of greater, less, or equal, which are the chief objects of geometry, are far from being so exact or determinate as to be the foundation of such extraordinary inferences [as those arising from the doctrine of the infinite divisibility of space]. Ask a mathematician what he means, when he pronounces two quantities to be equal, and he must say, that the idea of equality is one of those, which cannot be defined, and that it is sufficient to place two equal qualities before any one, in order to suggest it. Now this is an appeal to the general appearances of objects to the imagination or senses, and consequently 1 P. 37 ; ef. Brede, Der UntersoMed d. Leh/ren H., p. 35. 2 p. 134. 3 P. 129 n. 9 130 Hume's treatise and inquiet. i can never afford conclusions so directly contrary to these faculties." This passage was omitted after the edition of 1751, but the remainder of the note was retained. It contains the following sentences: "If this be admitted [that there is no such thing as ab- stract or general ideas] (as seems reasonable) it fol- lows that aU the ideas of quantity, upon which mathe- maticians reason, are nothing but particular, and such as are suggested by the senses and imagination, and consequently cannot be infinitely divisible. It is suffi- cient to have dropped this hint at present, without prosecuting it any farther. ' ' Now if all the ideas of quantity are "nothing but particular, and such as are suggested by the senses and imagination, " it is evident that geometry is not a perfectly exact science. That it contains "contradictions and absurdities," Hume explicitly affirms, if it be assumed that there are gen- eral ideas. He denies the assumption, however, and in that manner thinks to escape the contradictions. Yet his attempt to do this in the essay on "The Meta- physical Principles of Geometry" does not appear, to have been successful. Finally, it must be observed, that although Hume, in the Inquiry, omitted a specific criticism of reason and the senses, he said enough to indicate that the logical treatment of mathematics was omitted in the later work, not because he had changed his opinions on this subject, but because no "durable good or benefit to society" could be expected to result from such criticism.^ Thus he asserts i^ "The chief objec- tion against all abstract reasonings is derived from the ideas of space and time ; ideas, which, in common life ' P- 131. J Pp. 128, 129. KNOWLEDGE, INTUITIVE AND DEMONSTRATIVE. 131 and to a careless view, are very clear and intelligible, but when they pass through the scrutiny of the pro- found sciences . . . afford principles, which seem full of obscurity and contradiction. , . , The demon- stration of these principles seems as unexceptionable as that which proves the three angles of a triangle to be equal to two right ones, though the latter opinion be natural and easy, and the former big with contra- diction and absurdity. Reason here seems to be thrown into a Mnd of amazement and suspense, . . . She sees a full light, which illuminates certain places ; but that light borders upon the most profound dark- ness. And between these she is so dazzled and con- founded, that she scarcely can pronounce with cei^- tainty and assurance concerning any one object." Even with regard to "the skeptical objections" to the reasonings concerning matters of fact, the author de- clares that, "while the skeptic insists upon these topics, he shows his force, or rather, indeed, his own and our weakness; and seems, for the time at least, to destroy all assurance and conviction."^ But of course, as before, nature comes to the assistance of reason. The great subverter of "excessive skepti- cism" is action. Nature is always too strong for prin- ciple." An evident implication of these passages is that although the mathematical sciences possess em- pirical certainty, no science possesses absolute or a priori certainty. It is now manifest that Hume's view of mathe- matics, in the Inquiiy, is substantially the same as that in the Treatise. Arithmetic, algebra, and geom- etry are not a priori sciences, but empirical; for "the 1 P. 131. ' 2 Ibid. 132 Hume's treatise and inquibt. ideas" of "the mathematieal sciences," having been derived from impressions, are "sensible."^ Arith- metic, algebra, and geometry are not absolutely or a priori certain sciences, for the advantages and disadvantages of the mathematical and moral sciences "nearly compensate each other, and reduce both of them to a state of equality."* And geometry is not a perfectly exact science, for "all the ideas of quan- tity, . . . are nothing but particular, and such as are suggested by the senses and imagination."' But Hume says that arithmetic, algebra, and geometry are "intuitively or, demonstratively certain."* Very true; this is in his epistemological account. He made the same statement in the Treatise. He does not mean, of course, that the mathematical sciences are a priori intuitively or demonstratively certain. But he asserts that propositions in mathematics ' ' are discoverable by the mere operation of thought."" Yes, he means after the ideas have been derived from sensible objects. Yet he also affirms, that "the only objects of the abstract sciences or of demonstration are quantity and number";* that these sciences are a "more perfect species of knowledge"^ than are mat- ters of fact; and that they are "the only proper ob- jects of knowledge and demonstration. "« In aU these statements Hume, from his point of view, is perfectly correct. It is the traditional philosopher who is in error iu inferring from them a priori exactness and certainty, through reading the thoughts of rationalism into the words of Hume. §25. References to Mathematics in Hume's other 1 p. 50. » im. 3 P. 129 n. ' P. 20. »P. 21. e P. 133. ' Ibid. 8 p. 134. KNOWLEDGE, INTUITIVE AND DEMONSTRATIVE. 133 Philosophical Works.— It avails little to appeal to Hume's other philosophical writings for additional information on this subject. Yet if such reference be made, it tends, on the whole, to confirm the con- elusion liiat has already been arrived at. In the Treatise of the Passions the author states:^ "The con- clusions [concerning the relations of ideas] are equally just, when we discover the equality of two bodies by a pair of compasses, as when we learn it by a mathe- matical demonstration ; and though in the one case the proofs be demonstrative, and in the other only sensi- ble, yet generally speaking, the mind acquiesces with equal assurance in the one as in the other." In the Treatise of Morals/^ "If you assert, that vice and vir- tue consist in relations susceptible of certainty and demonstration, you must confine yourself to those four relations, which alone admit of that degree of evi- dence." In the Inquiry concerning the Principles of Morals,^ "It would be absurd ... to infer, that the perception of beauty, like that of truth in general problems, consists whoUy in the perception of relations, and was performed entirely by the understanding or intellectual faculties." In the Dialogues concerning Natural Religion,'^ "Let the errors and deceits of our very senses be set before us ; the insuperable difficul- ties, which attend first principles in all systems; the contradictions, which adhere to the very ideas of mat- ter, cause and effect, extension, space, time, motion; and in a word, quantity of all kinds, the object of the only science, that can fairly pretend to any certainty or evidence." In short, the statements in the treatise on The Passions and in the Dialogues imply that the 1 II, p. 223. 2 II, p. 240. ' IV, p. 263. * II, p. 381. 134 Hume's treatise aito iNQumY. mathematical sciences are empirical, and that geom- etry is not exact; but those in the treatises on Morals do not seem to have exactly the same implication, al- though they have not necessarily a contrary one. The difference just noticed between the statements on mathematics in the treatise of The Passions and the Dialogues, and in the treatises on Morals is easily explained. Not only was Hume exceedingly indefi- nite in his use of terms, but he did not recognize the same criterion of truth when discussing theoretical subjects, as when discussing practical subjects. Re- plying to Elliot,— who held that "an instinctive feel- ing" in the intellectual part of one's nature, "re- sembling the moral instinct in the moral part," corrects over refinement of subtlety or speculation, — he wrote :^ "Tour notion of correcting subtlety of sentiment, is certainly very just with regard to morals, which depend upon sentiment; and in politics and natural philosophy, whatever conclusion is contrary to certain matters of fact, must certainly be wrong, and there must some error lie somewhere in the argu- ment, whether we be able to show it or not. But in metaphysics or theology, I cannot see how either of these plain and obvious standards of truth can have place. Nothing there can correct bad reasoning but good reasoning. And sophistry must be opposed by syllogisms." § 26. Conclusion.— The results of the discussion may be summarized as follows:— 1. The Faculties of Mind.— The more important mental faculties recognized by Hume are sensation, memory, imagination, reason, reflection, and instinct. 1 Burton, Life, I, p. 324. KNOWLEDGE, INTUITIVE AND DEMONSTRATIVE. 135 He did not systematically classify, nor accurately de- fine them. He often experienced difficulty in de- scribing what he had in mind, and used, in both works, not only a variety of terms, but also, at different times, different terms to express the same thing. Most no- tably is this the case with regard to imagination and instinct. Knowledge begins with sensation. Mem- ory, imagination, and reason represent different stages of the same process. Reflection is a, peculiar mixture of , thinking andieeling. Instinct is not definable. It is often identified with imagination, habit, custom, or nature, and includes all those processes that cannot otherwise be explained. The only significant change, in the Inquiry, occurs in the treatment of. _instinet. Here Hume takes a place among modern psychologists. Instinct, having encroached on the domains of imagiaation, habit, and custom, becomes the faculty, par excellence. It mani- fests itself, at least by implication, below the level of consciousness, as tendencies to react upon the environ- ment. It subsists side by side with sensation, mem- ory, imagination, and reason, as impulses to action, and it appears at the higher end of consciousness, transcending reason, as the ultimate ends of action, ends for which reason can assign no reason.^ In this last sense, instincts— according to Hume, — or ideals of reason — according to the rationalistic philosophers, — are the assertion of the whole mind, the expression of the entire life of the individual. As such, they vary according to the stage of development of the person, of the community, of the nation, of the race. As people advance in civilization, contradictions natu- 1 Of. Everett, Essays: Theological aaid Literary, chs. I, VII. 136 hxjme's treatise and inquiet. rally and necessarily arise between imagination and reason, and between reason and instinct. Hume saw clearly that, in a world of progress, the solution of all the contradictions of human experience is absolutely impossible. And he does not seem to have been far from the right track when he regarded the solution of these contradictions, so far as that is possible, to lie largely within the functions of imagination and in- stinct. In the treatment of his problem, however, he soon encountered insuperable difficulties, because biol- ogy, which opens the ante-room of psychology, was unable to lift the latch, being only in its infancy in his day. 2. Intuitive Knowledge. — In the Treatise, intuitive, or sense and memory knowledge is based on the philo- sophical relations of resemblance, contrariety, and degrees of quality, and arises immediately from the observation, or comparison of impressions and ideas. It is not necessarily exact, nor certain, but is condi- tioned by the nature of the object observed, and the capacity of the mind observing. In the Inquiry, the classification of philosophical relations is omitted, and naturally also a treatment of intuitive knowledge ; yet on this latter question, Hume's view, by implication, seems to be the same as formerly. 3. Demonstrative Knowledge.— Mathematics, or knowledge developed by reason, is based on the philo- sophical relation of proportions in number and quan- tity. In the Treatise, Hume gave three different, although not distinct or separate expositions of mathe- matics: an epistemological account in Parts II and III, a logical, and a psychological account in Part IV. According to the-epistemological account, mathematics KNOWLEDGE, INTDITIVE AND DEMONSTEATIVB. 137 is an empirical science, because the ideas of number and quantity ar.e derived from tbe senses ; arithmetic and algebra are perfectly exact and certain sciences, because they possess a "precise standard"; but geom- etry is not an exact or certain science, because its first principles are based upon the general appearances of objects to the senses and imagination. According to the logical account, "all knowledge degenerates into probability," and would at last, were it not for the influence of custom, result in "a total extinction of belief and evidence. ' ' The psychological account pro- fesses to show how judgments in the mathematical sciences, like those in any other science, retain a cer- tain amount of assurance. Custom, or imagination, or instinct, or nature determines one by "an absolute and uncontrollable necessity" to judge and to believe, as weU as to breathe and feel. The degree of belief attending the judgment is, of course, greater, in short and sunple problems than in long and intricate ones. But in all cases, the quality or character of belief is the same, belief being "more properly an act of the sensitive, than of the cogitative part of our natures. ' ' In the Inquiry the logical and psychological ac- counts of mathematics are omitted. Hence, it has been the common opinion that Hume, in the later work, regarded mathematics as an absolutely certain science, based on a priori principles. And since, in the brief epistemological account that is given, arith- metic, algebra, and geometry seem to stand on an equal footing, the rationalistic philosophers, in ac- cordance with their favorite presuppositions, natu- rally thought that Hume had elevated geometry to the rank of an exact science. On the contrary, how- 138 Hume's treatise and inquiet. ever, the facts of the matter are, that he first regarded arithmetic and algebra as being on an empirical basis equally with geometry, and later modified his episte- mologieal account to such an extent as to show that mathematics is not an absolutely certain science, and that geometry is not a perfectly exact one. The four questions proposed at the beginning of the discussion are now answered. (1) According to Hume, mathematics is not an a priori science; (2) it is not an absolutely certain science; (3) geometry is not a perfectly exact science ; and (4) this seems to be the position of both the Treatise and Inquiry. It only remains yet to add a remark explanatory of the fourth answer, for as here stated, it is liable to mis- conception. Although it is true that, in neither work, is mathematics an a priori, or an absolutely certain science, nor is geometry a perfectly exact one ; it does not follow, by any means, that the general positions of the two works, on this subject, are identical. Log- ically, they are ; actually, they are not. Although the doctrine is essentially the same in the Inquiry as in the Treatise, the statement of it, as has repeatedly been pointed out, is quite different. And in this case, the difference in statement is so great that, without- implying any change of view on the part of the author, it produces a very remarkable change in the tone and attitude of the book. "While the doctrine of the Treatise is stated fuUy and boldly, that of the Inquiry is expressed briefly and hesitatingly. Yet the differ- ences in the later work are only of such a nature as can easily be explained. They arise from the omis- sion of the logical and psychological accounts of mathematics. And these omissions were made be- KNOWLEDGE, INTUITIVE AND DEMONSTRATIVE. 139 cause: (1) Htane aimed, in the Inquiry, to give a brief and popular exposition of his theory of knowl- edge; (2) he intended to deal with mathematics at some future time; and (3) he thought that no "dur- able good or benefit to society" could be expected to result from a detailed statement of the skeptical ob- jections against reason or the senses. When Hume maintains that mathematics is an em- pirical science, and consequently, not possessed of absolute or a priori certainty, he is indubitably right. But when, through his failure to perceive that the fundamental characteristic of general ideas is the epistemological element, he contends that geometry is not. a perfectly exact science, he is unquestionably wrong. As Aristotle held that, in any science, one should expect only that degree of accuracy which is conformable to the nature of the subject; so Hume held that the different sciences, being all empirical, admit of varying degrees of exactness and certainty, according to the nature of the subject-matter. But Hume, again Kke Aristotle, did not succeed, in all respects, in carrying out his principle. The limita- tions of his time, and his own p^chical predisposition — his visualizing imagination,— were obstacles too great for his philosophical genius entirely to overcome. CHAPTER VII. THE IDEA OP CAUSE AND EFFECT. § 27. Causation the Basis of Beasonvng Concern- ing Matters of Fact. — The idea of causation has been an object of reflection ever since the dawn of rational speculation, and the validity of belief in causality has frequently been questioned throughout the history of philosophical inquiry. Egyptian and Jewish, Hindoo and Persian, Greek and Roman, — all historical races have had their distinctive representatives of empiri- cism and skepticism. It is in English philosophy, however, by intensely practical men, that the idea of cause and effect has been subjected to the most search- ing examination. Glanvill affirmed emphatically, that necessary connection is not perceivable by the senses. Hobbes, Locke, and Berkeley followed, more or less closely, along the same line of Pyrrhonism. They prepared the way for Hume. And although Hume, in his criticism of the idea of cause and effect, did little more, perhaps, than sum up and present ia a new form the logical results of his predecessors' re- flection; nevertheless, to him belongs the distinctive honor of being the first philosophical writer, who gave a final analysis of the conception of causality from the standpoint of pure empiricism. Hume's exam- ination of the idea of cause and effect is not only an invaluable contribution to speculative thought, but also an imperishable monument to the intellectual acumen and subtle analytical power of one of the greatest of the many keen thinkers of Scotland. 140 THE IDEA OP CAUSE AND EFFECT. 141 Cause and substance are the two poles of the phi- losophy of human nature. Having treated intuitive knowledge and demonstrative, Hume proceeded to -deal with that division of probability which he caUs proofs, reasoning proper, moral, or experiential. This species of reasoning is conversant with matters of fact. It is not, like intuitive and demonstrative knowledge, founded on the relations of resemblance, contrariety, degrees of quality, and proportions in number or quantity ; for since the contrary of matters of fact is conceivable, and therefore possible, knowl- edge of them is not obtained by means of reason. Nevertheless, the "arguments" in experiential, or empirical reasoning are regarded as being "entirely free from doubt and uncertainty."* All reasoning is of the nature of comparison. In comparison, one of the two objects compared, or neither, or both may be present to the senses or memory." If neither object is present, the reasoning is purely hypothetical.' This statement is analogous to Kant's famous dictum, "concepts without percepts are empty." When the two objects are present to the senses or memory, the act is called "perception rather, than reasoning." Similarly Kant said that "percepts without concepts are blind." When the two objects are present to sense or memory, the com- parison is based on the relations of identity and con- tiguity.* But in instances of comparison when only one object is present to the senses or memory, there is a conclusion drawn beyond experience. This is reasoning proper, or experiential reasoning. Its basis II, p. 423. "I, pp. 376, 384, 385; IV, p. 39. 'I, pp. 384, 385, 390; IV, p. 39. «I, p. 376. 142 Hume's treatise and dstquirt. is tlie relation of cause and effect.^ In order, there- fore, to discover the evidence for reasoning concern- ing matters of fact; that is, to learn the rational ground of experiential reasoning, it is necessary to examine the idea of cause and effect.'' § 28. Examination of the Idea of Cause and Effect. —The treatment of causation, in the two works, al- though similar in form, differs much in detail. In the Treatise, the discussion is exceedingly thorough, systematic, and ingenious. In the Inquiry, on the other hand, it is brief and comparatively simple;— chiefly, no doubt, because Hume was afraid that should he "multiply words about it, or throw it into a greater variety of lights, it would only become more obscure and intricate."' Pfleiderer* states that the argument in the Treatise, like that on causation in Kant's Eritik, proceeds analytically, while the reason- ing in the Inquiry, as in the Prolegomena, proceeds synthetically. Eather it should be said, that the argument in both cases is essentially analytical, but in the later work the analysis is less prominent than in the earlier. In accordance with his usual method of argumenta- tion, Hume, in both works, opens the discussion by inquiring after the origin of the idea.° On this line of attack upon rationalism he had often won, and he again feels confident of achieving his wonted success. In the Inquiry, he states briefly, and then proceeds to prove, that the knowledge of the relation of cause and effect is not attained by intuitive perception, nor : I, p. 376; IV, p. 24. 2 1, p. 377; IV, p. 24. »P. 63. ''Empirismus u. Skepsis, p, 169 and n. 61, p. 377; IV, p. 24. THE IDEA OF CAUSE AND EFFECT. by a priori reasoning, "but arises entirely from ex- perience. ' '^ /in the Treatise, Hume is at his best in the discussion of causation. Slowly and thoroughly he prepares for an exhaustive analysis of his problem, and then, with rare skill and subtle penetration, he winds his tortuous way through an argument of nearly one hundred pages, until finally he reaches his intended goal. It may be thought that the idea of cause and effect is derived by means of the senses, or by means of reason, or by means of a supra-natural power, or by means of the imagination. These are the only possible sources; and Hume examines them I all. He first asserts that the impression of causatipn is not perceived as a quality of j^JecfsX .eonsequentl;^, the idea ''^musFbe derived from some. reZafeat, among objects."^ ' Next he inquires what relations are dis- coverable between objects that are "considered as causes or effects." These are two: (1) ^ontigui^, (2) succession.^ It is supposed, however, that there is^^stiU another elemonrTn'cSusatidn^^^^^^^^ cojoneclfon ; that is, that there is a necessary connec- tion between objects or events that are causally re- lated. Moreover, it is the element of necessary con- f nection which, is always regarded as.4he.,essenti:al,p,a,rt I of^^causality. Hence this is the peculiar problem to/ be investigated.* But necessary connection among objects or events is not perceived by the senses either as a quality, or as a relation. Then Hume deems it advisable "to leave the direct survey" of the ques- tion, and "beat about aU the neighboring fields." In this manner he hopes to find "a hint" that may serve to clear up the dijB&culty. " He soon discovers a clue I Pp. 24, 25. «P. 377. » Pp. 377, 378. «P. 379. sp. 380. 144 Hume's treatise and inquiby. in two questions bearing on the subject, one the gen- eral question of causation, the other the particular' question. These two questions he then examines in succession; whereupon, he comes back to the point at which he turned aside, and deals directly with the idea of necessary connection. Accordingly, the treat- ment of the relation of cause and effect falls into three main divisions:— I. The general question of causation.^ II. The particular question of causation.' III. The idea of necessary connection.' The accounts ia both works may be examined to- gether. / I. The general Question of Causation. The gen- eral question of causation is stated in the Treatise as follows:* "For what reason we pronounce it neces- sary, that every thing whose existence has a begin- ning, should also have a cause?" and in the Inquiry:' "What is the foundation of aU our reasonings and conclusions concerning [the relation of cause and effect] ? ' ' These two questions, though differently expressed, are essentially the same. Huxley' asserts that the evidence by which Hume supports his con- clusion in the Inquiry, concerning the general ques- tion of causation, "is not strictly relevant to the issue." And several writers' state that he omits al- I I, pp. 380^83; IV, pp. 24-38. "I, pp. 383-422 J IV, 24-47. ' I, pp. 450-466; IV, pp. 50-65. * P. 380. 6 p. 28. e_Hume, p. 118. /Cf. Selby-Bigge, Hume's EnqvAries, Introd.; Ueberweg- fieinze, Qesoh. d. Phil., Ill, p. 201; Riehl, Der pMlosopMsclie Eriticismus, I, p. 114 and n.; Vaihinger, Kommentar «« Kant's Kritik, I, pp. 347, 349. THE IDEA OP CAUSE AND EFFECT. 145 together tlie consideration of this question in the later work. Now it may be admitted that part, at least, of the evidence hy which he supports his conclusion iu the Inquiry is not strictly relevant. But it is contended that the two questions, as above stated, are for Hume's purposes practically equivalent.' They imply each other in such a manner that the answer to both is the same. /in the Treatise, the author professes to show that neither intuition, nor demonstration,— neither the senses and memory, nor thought and reasoning— is the ground of the opinion that every effect must have a cause. For if the necessity of a cause for every effect could be intuitively perceived, or could be demonstrated by reason, the contrary would be in- conceivable. But that the contrary is not inconceiv- able, he claims to prove by the following argument:" "As aU distinct ideas are separable from each other, and as the ideas of cause and effect are evidently dis- tinct, it win be easy for us to conceive any object to be non-existent this moment, and existent the next, without conjoiuing to it the distinct idea of a cause or productive principle." Accordingly, he concludes that ^ opinion of the necessity of a cause for every effect arises wholly from "observation and experi- ence, "'i Jnthe Inquiry,* Hume asserts^hat^,llthe. knowledge '^o5rinie"relatton" aOa^SS^aJid^ notfinliny ins^affie, atteinedl by^ rea^omn^^ nOTDy me intuitive perception_of the .q ualities of ahi&eis^,l^^MiS^iisesrenfaelf~^&oioa. experience." His chief argument is similar to that in the Treatise: iCf. Caird, The Critical Phil, of Kant, I, p. 133 n.j Jahn, D. H. Ca/usaUtatstheorie, pp. 6, 41. ap. 381. aP. 3»3. *P. 24. 10 146 hume's treatise and inqtjiey, ' 'Every effect is a distinct event faom its ca use. ' '^ Consequently, it follows that "there is nolTm any single, particular instance of cause and effect, any thing which can suggest the idea of power or neces- sary connection. "2 Of course when one abandons the atomistic view of mind, the petitio principii in this reasoning becomes obvious. But on Hume's presup- positions the argument is perfectly valid. If "every effect is a distinct event from its cause," or if it is easy "to conceive any object to be non-existent this moment, and existent the next, without conjoining to it the distinct idea of a cause or productive principle," there is no real necessity to think that every effect must have a cause ; and the supposed necessity, so far as it exists, must be explained on the ground of ex- perience. The next question should naturally be, how experi- ence gives rise to the opinion, that "whatever begins to exist, must have a cause of existence?"' But in the Treatise, Hume finds it "more convenient to sink this question" in the particular problem of causation, remarking: "It will, perhaps, be found in the end, that the same answer wiU serve for both." And in the Inquiry, instead of asking how experience gives rise to the principle that every event must have a cause? he asks a related question, viz., "WbalLis.„the^ foundation of all conclusions from experience?"* TEesftWff^questions, that"*of the Treatise and that of the Inquif^, may now be considered. II. The particular Question of Causation. The particulai„.ques,tion of jeausati^^ itself into 1 P. 27. «P. 52. »P. 383. «P. 28. THE IDEA OF CAUSE AJSTD EFFECT. 147 three parts :^ (1) "Wliyweconclude, that such par- ticular causes must .tecessamw have such ^articular effects f"~ (2) "What is the nature of that mference we draw from the one to the otherT' ""'(3)^ Whatjs"" the nature of "fixe oelief" we repose in the inferred idea ? The last of these problems will be left for con- sideration in the following chapter. The first ques- tion does not receive separate treatment, but is dealt with incidentally in connection with the second, Hume making the characteristic remark: "Perhaps it will appear in the end, that the necessary connection de- pends on the inference, instead of the inference de- pending on the necessary connection. ' " Consequently, the subject of immediate interest is the second division of the particular question of causation, viz., "Why we form an inference from, one,. ,[inst3,nee], to an- otlief ? ' ' And this question, it may be noted, resolves itself into that of the Inquiry at present under in-j., vestigation; for the reason or ground on which we form an inference' from one instance to another Vsi aeeording to Hunie, "the fouM^tiplpL^^,^^^ from experience. ' ' ~ The argument may now be presented in two forms, as the mode of reasoning is not exactly the same in both works. This change of method, however, seems to have arisen from Hume's different ways of stating the problem, or perhaps from his desire for brevity of treatment in the Inquiry. In the Treatise,' the author gives a brief account of experience, professing to show how, from the observation of antecedent and consequent in a number of particular instances, the idea of cause and effect gradually arises. The inf er- »I, pp. 380, 383. 21, p. 389. 'Pp. 388, 389. 148 hdme's treatise and inquiet. ence, therefore, from cause to effect, or from effect to cause is a transition of the mind from "a present impression of sense or memory" to a related idea. "Andj^e transition is founded, not on such a penetra- tion into the "essences" of objects "as may discover the dependence of the one upon the other," but on past experienc"^ Then the question occurs, whether, the transition is produced by reason, or by imagina- tion 1^ Were it produced by reason, it would be based on the principle of the uniformity of nature. Hence the following question presents itself, what is the ground of the principle of the uniformity of nature ? This principle is not established on intuitive knowl- edge, nor on demonstrative, — that is, it is not derived from the senses, nor from reason,— because a change in the course of nature is conceivable. Neither is it derived from probability, for probability is founded upon it." Eather it arises from constant conjunction or custom, and is, therefore, an assumption that can never be proved.' Consequently, the transition or inference is not produced by reason, but by imagina- tion, by means of the two primary laws of association,- resemblance and contiguity, that is, through the repe- tition of similar, instances or custom.* According to the Inquiry, jail conclusions from ex- perience "proceed upon the supposition, that the future will be conformable to the past?^ But then it must be asked, as before, what is the ground of the principle of the uniformity of nature? This prin- ciple does not rest upon demonstrative arguments, iP. 390. sp. 391. sPp. 392, 431, 545. *Cf. pp. 390, 393, 403, 414, 459, 461, 471, 509. sPp. 29, 31, 33. THE IDEA OF CAUSE AND EFFECT. 149 since a change in the course of nature implies no contradiction.' Neither does it rest upon probable reasoning or arguments from experience, since "all these arguments" are foimded on the principle of the uniformity of nature.* This priaciple is ^merely an assumption, a product of the [imagination Vhich arises from the constant conjunction of similar in- stances.' Consequently, "the foundation of all eon- elusions from experience-" is constant conjunction and custom.* Hence these two forms of the argument are ultimately one and the same. TConstant or cus- tomary conjunction of resembling objects has such an influence upon the imagination, that on the appearance of one the mind passes on to the thought of the other j] or as otherwise put,|resembling impressions and ideas that have been constantly conjoined introduce one another, so that the repetition of similar instances carries the mind beyond actual experience, and causes it to expect similar instances in the future under similar conditional [ inferenc e, therefore, is not an act of intuition,— of sense perception .— nor a process of demonstration, but is a transition of the imagina- tion produced by custoiiCl '(The foundation of all conclusions from experience" also, is ultimately cus- tom or habit!> The nature of custom, however, the author professes, in each work, not to explain. It is a sp^ecies of instinct, or "a principle of human nature, whijh is universally acknowledged, and which is well known by its effects."' But as in the case of the principles of association of ideas, no explanation of iPp. 31, 33. ijhid. 'Pp. 30, 32, 33. * Pp. 36, 37, 39, 40. 5 I, pp. 471, 475; IV, pp. 37, 40, 131, 150 Hume's treatise and inquiet. it can be given, except that furnished by experience and analogy/ It is now manifest that, in his treatment of the par- ticular question of causation, Hume has answered— at least after his own fashion— the question ia the Treatise for which the particular one was substituted, viz., how experience gives rise to the principle that "every thing whose existence has a beginning should also have a cause?" He had formerly shown that this principle is a conclusion from experience;' now he has explained the nature of inference, or experi- ential reasoning ; therefore, he has shown, how experi- ence gives rise to the priaciple that every event must have a cause.' He has answered this question in^ the Inquiry also. In the Inquiry he asked, what is the foundation of all conclusions from experience? Therefore he asked, at least by implication, what is the foundation of the principle that every event must have a cause ?— that principle being a conclusion from experience. And to explain that "the foundation of all conclusions from experience" is constant conjunc- tion and custom, is equivalent to showing how experi- ence gives rise to the principle that every event must have a cause. This mode of handling the matter is certainly ingenious. Under the form of many ques- tions, Hume arranged the argument to suit his con- venience, and implicitly assumed one of the main points to be proved.' To this assumption, of course, he was fuUy entitled, according to the fundamental principles of his system of philosophy. And it may ^Cf. I, pp. 321, 330, 392, 393, 471; IV, p. 37. ^Of. p. 144, above. 'Cf. I, p. 389. *0f. I, pp. 380, 381, 383, 385, 390; IV, pp. 24, 27, 30, 31. THE IDEA OF CAUSE AND EFFECT. 151 be noted that, on discarding this assumption, viz., that all perceptions are distinct and separable, Hume's position, although bereft of one of its conspicuous supports, is, in its essential import, or with but slight modifications, perfectly valid. Logically, the next question for discussion is the third part of the particular question of causation, viz., the nature of belief. But as it seems advisable to devote a chapter to this topic, we pass on to the last general division, that is, necessary connection. Ill- J!h e_Jdea of Necessar y C onnectkaL ^^In the fourteenth section of Part III of the Trej jise, and in the seventh section of the Inq uiry, Hume returns to the question which was left unanswered at the begin- ning of the discussion, and which was supposed to be conversant with the chief element of the idea of cause and effect, viz., the question of necessary connection.^ But having answered, inj;he maimer thatt_he-did,_t.he firaywojjuestions— the general one, and the particular one, — he has practically answered the third^tiiat of necessary connection. For if nothmg is kn own about causation except what is3iHv^^]^rBtixp£rience,^aQd iOlie^ultimate. ground of experience is custom, or instiact, then there^is^no dmentjof necessity, as com- monly understood, in the idea of cause and effect ^ Hume asserts :^ "The necessary connection betwixt V causes and effects is the foundation of our inference ' from one to the other. The foundation of our in- ference is the transition arising from the accustomed union. These are, therefore, the same." Thus he arrives by a process of reasoning at a conclusion sim- ilar to the assumption with which he had started out : 1 1, p. 379. 2 1, p. 460. 152 Hume's treatise and inquiet. "As all distinct ideas are separable from each other, and as the ideas of cause and effect are evidently dis- tinct, it will be easy for us to conceive any object to be non-existent this moment, and existent the next, without conjoining to it the distinct idea of a cause or productive principle."^ So far as we know, there- fore, or are capable of knowing, objects or events are related only by means of association and custom. Hence Hume, in explaining necessary connection, has really explained it away. Necessity exists only in the mind, not in objects. "Either we have no idea of necessity," he says,' "or necessity is nothing but that determination of the thought to pass from causes to effects, and from effects to causes, according to their experienced union." It might only remain now for Hume to show how the fiction of necessary con- nection has arisen. But as he has just examined "one of the most sublime questions in philosophy," he thinks it may be advisable to give a fuller account of his doctrine. For that reason, he brings forward some additional arguments to show that the idea is invalid. The two topics will be treated separately. 1. The idea of ne cessary connectianJLg.iov alid. As usual, in testing the validity of any idea, Hume brings forward his "articles of inquisition," and demands from what i mpression the idea of necessary connec- tion is derived ?' It is not derived by means of the senses, from the observat ion of objects, because-the only relations pgrceiyable among objects are contiguity^ andsucces^on.* It is not derived bymeans of thought ' I, p. 381 ; IV, p. 27. i 1, p. 460; IV, p. 62. 'I, p. 450; IV, p. 62. ^im. THE IDEA OF CAUSE AKD EFFECT. 153 or reasonin g, because reason ca^jproducen£new iiea^' Aj^jfis^LoLgSi^HlSMTa .' ' supreme spirit ' ' or the 0£erations of "deity," as the Cartegangjb^ldj^^. f^t^ doctrine of iimate ideas ^asjbeen^rejecte^andj)05v:gr is not disepveraMe in spirit any more than JQ^bod^. ' These are the main arguments adduced, and thus far the reasoning, in both works, though different in form, is identical in import. In the Treatise, however, Hume incidentally ad- mitted that if the idea of power were once acquired, power might be attributed to " an unknown quality. ' ' ' This admission seems to have been seized upon by his opponents as a point of vantage, for an additional argument was introduced in the appendix to refute those who assert "that we feel an energy, or power, in our own mind," and then "transfer that quality to matter." "But to convince us how fallacious this reasoning is," says Hume,* "we need only consider, that the will being here considered as a cause, has no more a discoverable connection with its effects, than any material cause has with its proper effect. So far from perceiving the connection betwixt an act of volition, and a motion of the body; it is allowed -that' no effect is more inexplicable than the powers and essences of thought and matter. Nor is the empire of the will over our mind more intelligible. ... In short, the actions of the mind are, in this respect, the same with those of matter. We perceive only their constant conjunction ; nor can we ever reason beyond 1 I, p. 452; IV, pp. 52, 53. 2 I, pp. 454, 455; IV, pp. 58, 59, 60. » I, p. 455. ' I, p. 455; of. p. 541 for a verbal contradiction of the last sentence. 1M>^ Hume's teeatisb akd inqxjiet. it. No internal impression has an apparent energy, more than external objects have." This argument was again brought forward in the Inquiry, and pre- sented with considerable fulness of detail.^ Its im- portance was probably overlooked, or underestimated in the earlier work. This is one of the very few instances in which there is any development in the Inquiry, of Hume's doctrine. Otherwise the argu- ment has little significance, for it had been implied^ in the Treatise.'' The conclusion of the reasoning in \ both books is exactly the same, viz., one never has an ] impression of power or necessary connection, and con- sequently cannot obtain a valid idea of it. 2. How the Fiction of necessary connection arises. Itjs thought,,howCTerj_that ojie^as^aji . id£a„of _p.Qw:ejc or of necessary connection between objects or events ; hence, the author's next task is to account for this fiction. Concerning the origin of the idea, the esi planation of the two works is identical.' It is briefly \ as follows : One evCTj; is observed^ to follow another immediaMyj;_jphen^hi3,, inst^ immediate succession has .bgeri,, repeated a number oi times, the repetition, through custom, or instinct,^pro- duces a new sentiment or feeling, an impressipn, of, reflection; and this impression of reflection, .gives„ rise to the^idea of power or„nec.essaEy„SPnn,ectAQii/ "Necessity^then," says Hume,* "is the effect of this observation, and is nothing but an internal impression lof the mind, or a determigyationJojEarry_aj^^boughte_ If roiQ OM oy ect^tcraJQottLer/^^^^^ power I or necessag; eonjaection Js..a_produ£tuoi^lhajmaginar | tion. --,^^ >'Pp. 54-57. 2 p. 455^'^ -^__ » I, pp. 457, 468; IV, pp. 61, 62. *I, p. 459; cf. IV, p. 63.~ THE IDEA OF CAUSE AND EFFECT. 155 In the Treatise/ the author expressed an apprehen- sion that although his "foregoing reasoning" appeared to him "the shortest and most decisive imaginable," yet "with the generality of readers" the..bias_of the mind to regard necessary connection as something "~«b-je6ti-ve- would prevail, and give them a prejudice against his doctrine. This bias he explained in the following manner:' "It is a common observation, that the mind has a great propensity to spread itself on external objects, and to conjoin with them any internal impressions which they occasion, and which always make their appearance at the same time that these objects discover themselves to the senses. . . . The same propensity is the reason, why we suppose neces- sity and power to lie in the objects we consider, not in our mind, that considers them." These remarks are omitted in the Inquiry. But the omission is not significant, since the same explanation of the bias of mind here referred to is implied in a foot-note,' and is again stated in The Natural History of Religion.* TV. Conclusion. Hume's account of necessary connection, particularly that in the Treatise, is by no means so simple as might appear from the above state- ment. The discussion abounds in repetitions, obscuri- ties, and even inconsistencies. Yet the inconsistencies are often verbal rather than real, arising from the use of terms, sometimes purposely, in a loose and popular sense. It is allowed, for instance, that there are powers and operations of nature;^ also power or effi- cacy is spoken of as uniting causes and effects.' But Hume explains that, "iu all these expressions, so ap- plied, we have really no distinct meaning, and make iP. 461. ^Ibid. »P. 64. av, p. 317. =?. 462. eP. 456. Cje) Hume's treatise and inquiey. use only of common words, without any clear and determinate ideas."' Agam_t]igJde3L.Qf--power,^«f necessit y- or of necessary connection is said to arise from a new impression, or determination," from sim- ilar^^m§t§afiktJLlfe£^^J-?OStMUi£-similai^ ^pm„ an ioterjiaL Jmp,Eession,,or^iroEire&siip^.]^gflg^ tion,* from a_ propensity," from the repetition of re- Sted objects,' fromjb^afeit Q^Ji^stom^ anOrraaJma^ ination.^ If Hume had enjoyed the opportunity of presenting his system of philosophy in the class room, or had experienced the necessity of defending it as he formulated it, he would have been more precise in his use of tenos, and more consistent in his form of ex- pression. Hi^various^accDunts - of .the. deriyatioiL of the idea of necessary eonnection,may be summarized.. briefly. asJx)llows': The terms efficacy, agency, powCT^. Jorce, energy, necessity, connection, and pro'ductivei quality, "are all nearly synonymous."* Repetition,'".], cnstmn. ^^ similar instances.'' constant conjunction,' ^-}; instinct,'* or imagination " produce a determination ; of the mind, a prnpensdtv, ba.bit, p.nstoma.ry trfl.naitinTi^^r mr impression of reflection. This determination," pro-r ipensity,''' habit,'* customary transition" — qualities of'- pppee p llous, ' " ^— Of- intemal-imprfissign" is equivalent i XO power, necessit y, or necessary connec^^. The idea 1 P. 457; ef. IV, p. 29 n. ^ Pp. 450, 451, 463. 'Pp. 457, 459. »P. 460. ^Ibid. 8 P. 461. I P. 508. ^8 P. 511. SI, p. 451; IV, p. 51. "I, pp. 450, 461. "Pp. 460, 464, 511. "P. 459. "P. 464. »P. 471. "Pp. 464, 511. lePp. 451, 459, 460, 461, 463. "P. 460. >8 Pp. 429, 508. "P. 461. sojJitJ. a Pp. 459, 460. THE IDEA OF CAUSE AND EFFECT. 157 of power, of necessity, or of necessary connection is a copy of an internal impression, or impression of reflec- tion. ' Conseguentty, the idea^^ of power, of ^neeesaty, or of_necessaiy connection arises immediately or div; rectly from a deterniinaT;ion""of"tHe~mmd, propensity,, habit, customary transition^ internal „impr essionf^or^ the imagination; and^jngdiately or indirectly, fro repetition of relat^ed^objectSj_obseryat^^^ instances, constant conjunction, custom, or instinct. § 29. Misconceptwm^fWMiM'^tlnMSs'.—'Wromihe above examination of Hume's treatment of the idea of cause and effect, it is evident that the position of both works is substantially identical.' There are dif- ferences in the manner of statement, it is true, but these do not seem to be significant. Some of Hume's interpreters, however, put forward the claim that, with respect to certain aspects of the question, there are real and important differences in the Inquiry. The opinions of these writers, as well as a few mis- conceptions of others regarding Hume's view of causality call for some further consideration. Selby-Bigge* also asserts that, in the Inquiry, "the tiguity practically drops out altogether" ia "the account of the origin, in particular cases, of the idea of cause and effect"; and that "the account of causa- tion, ... is left hanging in the air when the sup- port of the theory of succession has been withdrawn." There does not seem to be sufficient ground to warrant these statements. Hume, it is true, affirms that "all 1 Pp. 454, 460, 463. 2 Cf. Brede, Der Untersohied d. Lehren H., p. 39 ; Pfleiderer, Empirismus u. Skepsis, p. 169 and n. s Bume's Enquiries, pp. xiii, xr. 158 Hume's teeatise and inquiby. arguments from experience are founded on the sim- ilarity, wMch we discover among natural objects, and by which we are induced to expect effects similar to those, which we have found to follow from such ob- jects."^ In like manner he had expressed himself in the Treatise.'' The passage just quoted, however, and several others in the Inquiry of a like import, do not mean that the relation of resemblance has now as- sumed the functions formerly exercised by contiguity and succession in explaining the origin, in particular cases, of the idea of cause and effect. On the con- trary, several statements clearly indicate that the relations of contiguity and succession play, respec- tively, the same r,61e here as in the earlier work. Thus Hume asserts:^ "Suppose a person, though en- dowed with the strongest faculties of reason and re- flection, to be brought on a sudden into the world; he would, indeed, immediately observe a continual succession of objects, and one event following an- other; but he would not be able to discover anything farther. . . . Suppose again, that he has acquired more experience, and has lived so long in the world as to have observed similar objects or events to be constantly, conjoiaed together; what is the conse- quence of this experience? He immediately infers the existence of one object from the appearance of the other." Also, when speaking of the idea of necessary connection, he says:* "All events seem entirely loose and separate. One event foUows an- other; but We never can observe any tie between them. They seem conjoined, but never connected." And in ^P- 31. 2 p. 391. sPp. 36, 37; of. pp. 24, 30, 33. * P. 61. THE IDEA OP CAUSE AND EFFECT. 159 a note in the edition of 1751 he made the decisive remark:^ "A cause is different from a sign; as it implies precedency and contiguity in time and place, as well as constant conjunction. ' ' The fact that con- tiguity is omitted in the definitions of cause given in the Inquiry is not significant, since the meaning of the word is clearly implied.'' Selby-Bigge^ also asserts that, in the Inquiry, "the distinction between causation as a philosophical and a natural relation is altogether dropped." This statement is not justified. In the Treatise,* Hume gave two definitions of cause, one as a philosophical relation, the other as a natural relation. In the In- quiry," he gave two corresponding definitions. These are briefer than those in the Treatise, but they are similar in meaning. For reasons already given,' the author omitted in the later work an explicit distinc- tion between natural and philosophical relations. As might be expected, therefore, in the definitions of cause, this distinction, although implied, is not form- ally expressed. In the section on "Liberty and Necessity," this same distinction is again implied. Hume asserts:^ "Nec^sity may_^be_defined^t\TO conformably to the tWQ definitions, of _ cause, . of which . it makes an essential part. It consists either in the constant'' con junction of like ' oB jects^ or in the infer- ence of the undCTstanding fr,om_pne_objectjtQ ,an- ptKer." "That is, necessity, like cause, may be re- garded either as a philosophical, or as a natural 1 IV, p. 64. 2 IV, p. 63; cf. p. 79. " Himie's Enquiries, Introd. 'P. 465. 'P. 63; cf. Brede, Der Unterschied d. Lehren H., p. 39. : Pp. 80-83. ' P. 79. 160 Hume's treatise and inquiet. relation. Selby-Bigge's account of Hume's treat- ment of causation is somewhat obscure, no doubt owing to brevity of statement. Indeed it hardly appears to be perfectly consistent. For although he says that "contiguity practically drops out alto- gether" in the account of the origin, in particular cases, of the idea of cause and effect; he also says: "Contiguity, . . . drops out of the Enquiry as a philosophical relation, though it must be supposed to exert its influence as a natural relation."^ It is suf- ficient to remark here that Selby-Bigge's distinction between natural and philosophical relations does not exactly conform to that of Hume. Indeed the editor of Hume's Enquiries does not seem to be quite free from the bondage of that "relationism" which weighed like a nightmare on the mind of Green, and gtiU vexes sore the souls of his readers. According to Peterson,^ the explanatory definition of cause, inserted in edition K of the Inquiry— 1753- 54— "is identical with the traditional doctrine" of causation. And Selby-Bigge' contends that this clause added "in italics can hardly be regarded as a paraphrase or equivalent of the main definition" in the Inquiry. It is usually unfortunate for critics to differ diametrically with their author in the inter- pretation of his language. In edition K of the In- quiry, after defining cause as a philosophical relation, Hume added the following sentence:* "Or, in other words, where,, if the first object had not been, the second never had existed." Of course, it might seem ' Hume's Enquiries, pp. xv, xvi. « Phil. Rev., Vol. VII, p. 47. ' Hume's Enquiries, Introd. « P. 63. THE IDEA OP CAUSE AND EFFECT. 161 to a casual observer as if this new definition were "identical with the traditional doctrine" of causa- tion, or at least as if it were not an "equivalent of the main definition in the Inquiry." But Hume re- garded it as being identical with his doctrine of causation; it is his own definition of cause expressed ' ' in other words. ' ' Furthermore, it may be noted that Hume fairly guarded himself from a mistaken interpretation like that of Peterson or of Selby-Bigge when he remarked, ia a note on the succeeding sec- tion:^ "If a cause be defined, that which produces any thing; it is easy to observe, that producing is synonymous to causing. In like manner, if a cause be defined, that "by which anything exists; this is liable to the same objection. For what is meant by these words, 6j/ which f Had it been said, that a cause is that after which anything constantly exists; we should have understood the terms. For this is, indeed, all we know of the matter. And this con- stancy forms the very essence of necessity, nor have we any other idea of it. ' ' Brede^ states that, in the Inquiry, there is a higher estimation of the worth of the causal inference than in the Treatise. On the other hand, Selby-Bigge asserts:' "The distinction [between natural and phi- losophical relations] in the Treatise is indeed most bewildering, but, with its disappearance in the En- quiry, the relation of causation becomes more com- pletely subjective. ' ' While Peterson* afSrms that, in the Treatise "the subjective aspect is made still more 1 P. 78. 'Der Unterschied d. Lehren H., p. 39. ' Slime's Enquiries, p. xvii ; cf. p. xv. « Phil. Bev., Vol. VII, p. 45. 11 162 Hume's teeatibe and rNQUiET. prominent" than in the Inquiry. The correctness or incorrectness of these conflicting assertions can be shown only by appealing to the author himself. No doubt it is tedious to resort continually to quotations. But there is no other method of dealing with the question under discussion. The subject will be dealt with as briefly as possible. In the Treatise Hume asserts:^ "We have already taken notice of certain relations, which make us pass from one object to another, even though there be no reason to determine us to that transition; and this we may establish for a general rule, that wherever the mind constantly and uniformly makes a transition without any reason, it is influenced by these relations." The relations are resemblance, contiguity, and cause and effect.^ But cause and effect arises from resemblance and constant conjunction, that is, from resemblance, contiguity, and custom. And the causal inference is produced, not by the relations of resemblance and contiguity simply, but by the repetition^ of these relations, that is, by custom. Hence Hume says later, "aU reason- ing concerning matters of fact arises only from cus- tom."' In the Inquiry he states:* "Though we should conclude, ... as in the foregoing section, that, in all reasoning from experience, there is a step taken by the miad, which is not supported by any argiiment or process of the understanding, there is no danger, that these reasonings, . . . wiU ever be affected by such a discovery. If the mind is not en- gaged by argument to make this step, it must be in- duced by some other principle of equal weight and 1 P. 392. s p. 393. = p. 487; 1, p. 279 n.; of. Zimels, Da/oid Humes Lehren vom Qlauhen, pp. 10-12. 172 BELIEF. 173 mediate liveliness of an impression." Neither of these views is quite correct. Hume's treatment of; belief is certainly not clear, but on this point it is not, necessarily inconsistent. To place the characteristic of belief, when dealing with "reasonings from causa- tion," in the derived "force and vivacity"^ of an idea does not preclude the author from attributing belief to impressions also. It is not surprising, there- fore, that he occasionally speaks of it in this latter sense, and ascribes to it a higher worth, or greater degree of assurance, than he does to belief of reason- ing concerning matters of fact. For instance, he as- serts:^ "The lelief or assent, which always attends the memory and senses, is nothing but the vivacity of those perceptions they present." Also,* "Impres- sions always actuate the soul, and that in the highest degree ; . . . Though an idle fiction has no efficacy, yet we find by experience, that the ideas of those objects, which we believe either are or wiU be existent, produce in a lesser degree the same effect with those impressions, which are immediately present to the senses and perception." And again,* "We may well ask. What causes induce us to ielieve in the existence of body? but it is in vain to ask. Whether there ie. body or not? That is a point, which we must tak0 for granted in all our reasonings." In the Inquiry, Hume refers only incidentally to belief of impressions; but he implies the same view as that in the Treatise. "Sensible objects," he says,^ "have always a greater, influence on the fancy than 1 1, pp. 385, 396; IV, p. 41. " P. 387. 3 p. 417. «P. 478; cf. pp. 388, 448, 449. 6 P. 44. 174 Hume's teeatise and inquiky. any other; and this influence they readily convey to those ideas, to which they are related, and which they resemble." Also in section xii he states:^ "It seems evident, that men are carried, by a natural impulse or prepossession, to repose faith in their senses ; . . . Even the animal creation are governed by a like opinion, and preserve this belief of external objects [impressions], in all their thoughts, designs, and actions." § 32. Belief of Ideas.— li is to the explanation of belief of ideas, or rather of the inferred idea in ex- periential reasoning, that Hume particularly ad- dresses himself; for he includes belief, in this sense, in the problem of causation. In the Treatise he asks •? "Wherein consists the difference betwixt believing and disbelieving any proposition ? ' ' And he replies : "The answer is easy with regard to propositions, that are proved by intuition or demonstration. In that case, the person, who asserts, not only conceives the ideas according to the proposition, but is necessarily determined to conceive them in that particular man- ner, . . . Whatever is absurd is unintelligible; nor is it possible for the imagination to conceive any thing contrary to a demonstration." In the Inquiry, he does not deal with intuitive or demonstrative proposi- tions,— probably because the answer was easy, and for the sake of brevity,— but only with belief concerning probable reasoning. To explain this belief is a special aim in both worjis. I. The Exposition of the Treatise. In the earlier work Hume asserts:" "The idea of an object is an essential part of the belief of it, but not the whole." 1 P. 124. ! P. 395. 3 p. 394, BELIEB". 175 Wherein then, it may be asked, does belief consist? An idea can be altered in any one of three ways: (1) A new element may be added to it; (2) the com- position of its parts may be varied; or(3) the manner of conception may be changed. Now belief of an idea, according to Hume, does not consist in any element, or part of a perception added to it, nor, in the order or composition of its parts. Consequently, it consists only in "the manner" in which the idea is conceived.^ "An opinion, therefore, or belief may be most accurately defined, a lively idea belated to or ASSOCIATED WITH A PRESENT IMPRESSION.'"' Briefly stated then, Hume's position is this : i^In_rfiasonjng _jeoaeernin§-jiiattera..£lJafit^-Jflwijie.a_^^ fro m an idea imagined mer ely in being more forcible,! "^^S-iSa^zIT^ fc jtc^i !Sn d belief"miy^^^;^;§ffidexij. equally, eitheraitiSeTOTce'"anH vivacity of an idea,/ or as an idea in its lorce andTvivacity ; smce it is J strictly speaking, neither the effect nor the cause oi the force and vivacity, but the force and vivacity\ itself.« ■ II. The Exposition of the Appendix. In order to make his former reasoning more convincing and to guard agaiast misconception, Hume discussed the sub- ject of belief somewhat further in the appendix. Here he made a few statements, however, which seem not only inconsistent in themselves, but also incom- patible with his former position. An apparent con- tradiction may first be disposed of. He afSrms, as usual, that belief consists in some sentiment or feel- ing, which is not "distinguishable from the concep- J P. 395. ' P. 396. » Of. pp. 396, 397 n., 399, 402, 405, 410. 176 Hume's teeatisb of human nature. tion."* Yet he admits that, in a certain ease of belief, viz., when the mind passes "from doubt and agitation to tranquility and repose," there is "a feel- ing distinct and separate from the conception. ' '" The latter statement is not, in reality, inconsistent with the former; since feeling, in this particular instance, is an attendant on belief, though not an essential part of it, and is distinct and separate from belief as well as from the conception. A further remark raises a greater difficulty. In the Treatise, when explaining his view of belief, Hume said:* "When you would any way vary the idea of a particular object, you can only increase or diminish its force and vivacity." In the appendix, he acknowledges that this statement is incorrect, and declares:* "I believe there are other differences among ideas, which eaimot properly be comprehended under these terms. Had I said, that two ideas of the same object can only be different by their different feeling, I should have been nearer the truth." No doubt had he said so, he would have been nearer the truth. For whatever feeling may mean, the author implies that it is something other than degree of force and vivacity. Hume, however, does not explain the meaning of feeling. On the contrary, he confesses that "it is impossible to explain perfectly this feeling or manner of conception."" He still contends that belief differs from fiction only in "the manner of its being conceived." But he adds:' "When I would explain this manner, I scarce find any word that fuUy answers the case, but am obliged to have recourse to II, p. 556. 2 1, p. 557. 8 p. 396; of. p. 397. * P. 560. 5 P. 398. 5 p. 397. BELIEF. 177 every one's feeling, in order, to give him a perfect notion of this operation, of the mind. An idea as- sented to feels different from a fictitious idea, . . . And this different feeling I endeavor to explain by calling it a superior force, or vivacity., or solidity, or firmness, or steadiness." Finally, he sums up the matter as follows:^ "Thus upon a general view of the subject, there appear to be two questions of im- portance, which we may venture to recommend to the consideration of philosophers. Whether there he any thing to distinguish belief from the simple conception beside the feeling or sentiment? And, Whether this feeling be any thing hut a firmer conception, or a faster hold, that we take of the object?" Both these questions, as indeed their forms imply, are answered in the negative. Now the question arises, what is Hume's doctrine of belief in the appendix? At first sight, it seems to be different from that in the Treatise ; but to what extent it may be different is by no means evident. The treatment ia the earlier work possessed two prom- inent characteristics: (1) Hume repeatedly professed to be able to explain fully the whole matter; (2) his explanation was generally to the effect that, belief consists in the degree of "force and vivacity" of an idea, arising from its relation to a present impression. Now he states: (1) Belief is nothing but a peculiar feeling, or manner of conception; (2) he is unable to explain perfectly the nature of this feeling. It might be thought, therefore, that his view of belief is en- tirely changed. Such, however, is not the case. In the Treatise, Hume maintained that the only differ- 1 P. 557. 12 178 humb's treatise and inquibt. ence between impressions and ideas, or between two ideas of the same impression, is a difference of degree, and, in general, he thought that this difference of degree could be adequately expressed by the phrase "force and vivacity."^ He still holds to the former statement, but he has abandoned the latter. A deeper psychological insight has enabled him to perceive that there are differences of degree between impressions and ideas, or between two ideas of the same impres- sion, other than those that can be expressed by the words force and vivacity. There is a difference of firmness, steadiness, faster hold, etc., which is not properly included under the former term. All these differences may be covered by the word feeling; but feeling does not indicate that wherein the differences consist. Consequently, with the attainment of this juster view, Hume changes somewhat the account of his doctrine. He explains that the differentia of be- lief is not degree of force and vivacity. The context shows, however, that by this statement he only means, that degree of force and vivacity is not always the differentia of belief; he implies that sometimes it is.* He now perceives clearly, what he does not seem to have fully realized, when writing the Treatise, that belief, psychologically, is not always the same thing. Peeling is an expansive term. Hence, in the ap- pendix, he asserts that the differentia of belief is feeling. He acknowledges that he cannot define this feeling. And when he endeavors to describe it he calls it "a superior force, or vivacity, or solidity, or firnmess, or steadiness";^ a "firmer conception, or a 1 1, pp. 314, 327, 375, 396, 397, 403, 417. • I, pp. 398, 556, 557. » I, p. 398. BELIEF. 179 faster hold, that we take of the oiject."^ Farther he did not carry his analysis of the problem. It is now obvious that the position of the appendix differs but little from that of the Treatise. It differs even less, however, than has thus far been represented. Two remarks will make this clear. (1) It is not at all improbable that interpreters have attached too much importance to the use of the term feeling in the appendix. In many instances, as for example, when it is said that "an idea assented to feels dif- ferent from a fictitious idea," Hume may mean simply that the idea is perceived differently, or is felt to be different. (2) Although in the earlier work, the author generally seemed to be fully con- vinced that belief could be adequately explained as a difference in degree of force and vivacity, yet at times he was not so positive. In the section, "Of the Causes of Belief," he acknowledged that there was "a little ambiguity" in the words "strong and lively";" and repeatedly he used a variety of terms corresponding with those which he employed later in the appendix. Thus he described belief as "a strong and steady con- ception of any idea";^ as "firmness or solidity" of ideas;* as "a more vvvid and intense conception" of an idea;" and as "some sensation or peculiar manner of conception."" He even designated it as feeling. "It is not solely in poetry and music," he declared,'' "we must follow our taste and sentiment, but like- wise in philosophy. When I am convinced of any principle, it is only an idea, which strikes more' > I, p. 557. 2 P. 405. 5 P. 397 n. « P. 406. » P. 418. 8 P. 475. ' P. 403. 180 Hume's treatise and inquiet, ? strongly upon me. When I give the preference to one set of arguments above another, I do nothing but decide from my feeling concerning the superiority of their influence." It seems, therefore, that the doc- trine of belief, in the appendix, is substantially the same as that in the Treatise. An examination of the account in the Inquiry tends to confirm this con- clusion. III. The Exposition of the Inquiry. The doctrine of belief in the Inquiry is exactly the same as that in the appendix. After asserting, as the conclusion of the whole matter, concerning experiential reasoning, that "all belief of matter of fact or real existence is derived merely from some object, present to the mem- ory or senses, and a customary conjunction between that and some other object" ; Hume acknowledges that his further researches into "the nature of this beUef, and of the customary conjunction," may, by the reader, who is not interested in abstract speculations, be neglected, without detriment to the understanding of "the following inquiries."^ Because of this state- ment,— and some others to be examined presently,— Brede* affirms that, in the Inquiry, not only is there assigned to belief a subordinate significance, but the concept of it is positively changed. In these two re- spects, Zimels' agrees with Brede, and maintains fur- ther that all the essential modifications of the doctrine of the Inquiry appear in the treatment in the ap- pendix. Several other writers hold the same opinion, on this question, as Brede or Zimels.* 1 P. 40. 2 Der Untersohied d. Lehren H., pp. 31, 50. ' Da/vid Humes Lehre vom Glauben, pp. 5, 6, 71. *0f. Stephen, Bist, of English Thought, I, p. 44 n. BELIEF. 181 Zimels is the best, as well as the most recent ex- ponent of this view. His whole Dissertation is an argument to show, that Hnme, in his exposition ia the Treatise, met with difficulties and even contradic- tions which obliged him to change gradually, although unconsciously, his form of statement ; that on review- ing the subject, in order to evade these difficulties and remove the contradictions, he modified his doctrine, in the appendix, to such an extent, that it not only conflicts with that of the Treatise, but contradicts one of the fundamental principles of his system; natu- rally, therefore, since his whole treatment was un- satisfactory, and he felt himself unable to master the problem, he cut short the exposition, in the Inquiry, and, passing over the chief difficulties, endeavored to make his view of belief consistent, both in itself, and with the general principles of his philosophy. Zim- els' argument is plausible as well as ingenious. It is more than plausible. It contains an element of valid- ity ; but is not quite conclusive. The treatment of belief, ia the Inquiry, is exceed- ingly brief, and also comparatively unimportant. It is brief, not because of difficulties realized by the author, but for quite other reasons : (1) Hume omitted a specific account of belief of impressions, and of ideas in intuitive and demonstrative reasoning, although he maintained that with regard to them there was no diffietilty whatever; (2) he aimed at brevity and sim- plicity on general principles; they were part of his avowed method; and (3) he was writing for a dif- ferent class of readers. The treatment is, compara- tively speaking, unimportant because : (1) As Hume's special problem was to explain belief of the inferred 182 humb's treatise and inquikt. idea in reasoning on causation, incidental treatment of the subject, in connection with the causal conclu- sion, was sufScient for his purpose; and (2) having dealt with this question in the appendix, as weU as in the Treatise, he had then nothing further to add, and also nothing to take away. It is said, however, that there are contradictions in the former account, and that these demand explana- tion. Here are some of those commonly pointed out. (1) In the Treatise, Hume asserted:^ "The vivacity produced by the fancy is in many cases greater than that which arises from custom and experience. "We are hurried away by the lively imagination of our author or companion ; and even he himself is often a victim to his own fire and genius." This statement does not imply a contradiction in the philosophy of human nature; it simply expresses a fact observable in every-day life. An untruth, if well told, is often believed; even the narrator may in time deceive himself, as do habitual story-tellers, "who by the frequent repetition of their lies, come at last to be- lieve and remember them, as realities."^ ,(2) Again, when sp,eaking of the effect of general rules, Hume affirmed in the appendix:' "A Mke reflection on gen- eral rules keeps us from augmenting our belief upon every increase of the force and vivacity of our ideas. "Where an opinion admits of no doubt, or opposite probability, we attribute to it a full conviction; though the want of resemblance, or contiguity, may render its force inferior to that of other opinions." The difficulty which, at first sight, appears here van- ishes on the slightest reflection. Hume was not a 1 P. 420. 2 I, p. 387. » I, p. 422. BELIEP. 183 modem, on experimental psychologist. He adopted the static view of mind, and also the atomistic. Yet he knew nothing of structural psychology, as distinct from functional. His analysis was always good, as far as it went; but often it did not go very far. Such was the case in the present instance. Hume was dealing with an exceedingly complex group of mental processes. When dealing with groups of this character, he divided each into two main parts, the present impression, and the related idea. He did not observe, however, that these two constituents are still complex; and failing in this respect, he also failed to note the existence of many of their less prominent elements. Besides these two chief constituents, he recognized certain relations subsisting between them, viz., causation, resemblance, and contiguity. But this impression, the idea, and the relations, as Hume regarded them, do not constitute the whole of a con- scious content. They do not include all of that "fringe of relations" in which a conscious content commonly has its setting. They are part of the totality of experience, as their objects are part of the real world. As such they are related by the same, or by other relations to other impressions and ideas. On account of these latter impressions, ideas, or rela- tions, which Hume did not recognize, the idea which he did recognize may be attended by a feeling of solidity, firmness, steadiness, faster hold, or force and vivacity, corresponding with the specific char- acter of the mental content. Hume, in the Treatise, appendix, and Inquiry, recognized the more prom- inent of these emotional elements, and designated them- according to their several characteristics. All 184 Hume's treatise And inquiet. were included, finally, ilnder tlie term feeling, the nature of which varied for each particular experience. General rules are based on causation, resemblance, and contiguity, and arise through repetition or cus- tom and generalization. They may produce belief as a feeling of firmness, steadiness, or faster hold, when the idea has comparatively little force and vivacity; or vice versa, they may inhibit belief, as when a very vivid idea, or even a hallucination, is held to be un- real by the person who experiences it. Further, it is said that the doctrine of the Inquiry is inconsistent with that of the Treatise. The ordy grounds for this assertion are Hume's admission, in the appendix,^ that "there are other differences among ideas, which cannot properly be comprehended" under the expression "force and vivacity," and his adoption, in the later writings, of the term feeling to express the exact nature of belief. But it has already been pointed out^ that the author recognized, in the earlier work, an ambiguity in the phrase ' ' force and vivacity," and that he used feeling, as well as all the other distinctive terms in the appendix, to explain belief. It may now be shown that aU the expressions employed for this purpose in the later work were also used in the earlier. In the Inquiry, Hume states:^ "The difference between fiction and ieUef lies in some sentiment or feeling, which is an- nexed to the latter, not to the former, and which depends not on the will, nor can be coramanded at pleasure. ... In this consists the whole nature of belief." In the Treatise,* he said, that "aU. probable 1 1, p. 560. 2 P. 179. » P. 41. * p. 403. BELIEF. 185 reasoning is nothing but a species of sensation"; that in philosopliy, as well as in poetry and music, "we must follow our taste and sentiment"; and that "the preference," or belief, of "one set of arguments above another" is only decided by one's "feeling." True, in the Inquiry, he admits:^ "were we to attempt a definition of this sentiment, we should, perhaps, find it a very difficult, if not an impossible task." And since he cannot easily give a definition, he offers "a description" of it :^ "I say then, that belief is nothing but a more vivid, lively, forcible, firm, steady concep- tion of an object, than what the imagination alone is ever able to attain. ' ' Although afterwards he adds :* "I confess, that it is impossible perfectly to explain this feeling or manner of conception, ' ' he concludes :* "Let us, then, take in the whole compass of this doc- trine, and allow, that the sentiment of belief is noth- ing but a conception more intense and steady than what attends the mere fictions of the imagination, and that this manner of conception arises from a cus- tomary conjunction of the object with something present to the memory or senses." This is the doc- trine of the Treatise, and all the terms used in the later work were used in the earlier." It is evident, therefore, that just as Hume saw, when writing the Inquiry, that degree of force and vivacity does not express the exact nature of belief ; so he somehow felt, when composing the Treatise, that it was not an adequate expression for belief in every case. Every one recognizes, of course, that there is a difference of treatment in the later work. Here the I P. 41. » P. 42. 3 Hid. « P. 43; of. p. 48. _« Pp. 396 n. 2, — 418. 186 HUME'S TREATISE AND INQUIBT. account of belief is more cautiously, more carefuUy, and even more correctly stated than formerly. This difference in exposition arose from the author's fuller psychological insight. So far, however, as the later account is more correct than the earlier, one may infer that it involves a change in the doctrine. This much is admitted; hut the change is only in the way of development. It is a variation of detail, not a modi- fication of principle. Consequently, it does not in- volve any inconsistency between the position of the Inquiry and that of the Treatise, on this question. Finally, it will be objected that, since, in the later work, there is a change in the treatment of belief, wherein it is recognized that belief does not always consist in degree of "force and vivacity," this new position seems to be inconsistent with one of the general principles of Hume's system, viz., that there is only a difference of degree between impressions and ideas.* In support of this view is adduced an- other form of the argument just examined. In the appendix,'' Hume admits that "more mature reflec- tion has discovered" to him an "error" in his reason- ing, in the Treatise, where he said that "two ideas of the same object can only be different by their different degrees of force and vivacity"; he concedes that "there are other differences among ideas, which cannot properly be comprehended under these terms" ; and he adopts, thereafter, the term feeling to express those differences exactly. This admission is worthy of consideration; but without examination, too much significance ought not to be attached to it. Hume 1 Cf. Zimels, Dcwid Ewmes Lehre vom Qlcmben, pp. 78, 79. ' I, p. 560. BELIEF. 187 used the foregoing words with reference to belief. Subsequently, when he wished to be exact, he em- ployed feeling to denote the diiferentia of belief; on all other occasions, however, he employed the same terms as in the Treatise. He did not imply, thereby, nor mean to express any contradiction in his doctrine of belief. In like manner, the correction, in the appendix, of the phrase "force and vivacity" is not meant to be inconsistent with the general principle, in the Treatise, above mentioned. Hume still recog- nizes only a difference of degree between an idea and its corresponding impression, or between two ideas of the same impression. When speaking precisely, that difference of degree must be designated by the term feeling, which includes force and vivacity, solidity, firmness, steadiness, or faster hold, etc., according to the constituent elements of the idea. But as a gen- eral rule, or speaking roughly, the difference of degree may conveniently be indicated by the words force and vivacity. This undoubtedly is Hume's position, on the question under consideration, when the verbal inconsistencies in his writings are removed. Exception may possibly be taken to our mode of interpretation, in attributing a twofold meaning to the expression "force and vivacity." In that case, we can only reply that we are explaining the doctrine of Hume. "We have merely made explicit, what he left implicit. For instance, in the appendix, he corrected the statement, made in the Treatise,* that "the idea of a particular object" can be varied only by increasing or diminishing its "force and vivacity," and said that there are other differences among ideas, 1 P. 369. 188 Hume's treatise and estquirt. "which cannot properly be comprehended under these terms." Yet later, in the Inquiry, he asserted:* "Here therefore we may divide all the perceptions of the mind into two classes or species, which are distinguished by their different degrees of force and vivacity. ' ' That is, in the former case he is speaking precisely, in the latter, generally. Moreover, while in the appendix he freely acknowledges his error in the earlier work, he does not admit that it involves any contradiction in his system. On the contrary, he implies, in the appendix and in the Inquiry, that his doctrine of belief is consistent, both with that in the Treatise, and with the fundamental principles of his philosophy.^ The remarks on this subject, in the appendix, were made, therefore, not in order to modify his former view, but as he said himself, to make his reasoning "more convincing,"* and "to guard against all mistakes in the readers."* In the light of what has been said, the similarity of Hume's doctrine of belief, in his several writings, may be seen at a glance from the following passages : In the Treatise he declares:" "When ... I com- pare an impression with an idea, and find that their only difference consists in their different degrees of force and vivacity, I conclude upon the whole, that belief is a more vivid and intense conception of an idea, proceeding from its relation to a present im- pression." And further:^ "It is certain, that the belief super-adds nothing to the idea [in reasoning concerning matters of fact], but only changes our > P. 13; of. p. 14. « Cf. I, pp. 555, 557; IV, pp. 43, 47, 49, 85. " I, p. 557. * I, p. 555. 6 p. 403. 6 P. 402. BELIEF. 189 manner of conceiving it, and renders it more strong and lively. . . . There enters nothing into this opera- tion of the mind but a present impression, a lively- idea, and a relation or association in the fancy betwixt the impression and idea; so that there can be no sus- picion of mistake." In the appendix he says:^ "I conclude, by an induction which seems to me very evident that an opinion or belief is nothing but an idea, that is different from a fiction, not in the nature, or the order of its parts, but in the manner of its being conceived. But when I would explain this manner, I scarce find any word that fully answers the case, . . . An idea assented to feels different from a fictitious idea, . . . and this different feeling I endeavor to explain by calling it a superior force, or vi/vacity, or solidity, or firmness, or steadiness." And in the Inquiry he states:^ "The difference be- tween fiction and belief lies in some sentiment or feel- ing, which is annexed to the latter, not to the former, and which depends not on the wUl, nor can be com- manded at pleasure. . . . Were we to attempt a definition of this sentiment, we should, perhaps, find it a very difficult, if not an impossible task." Finally,* "Let us . '. . take in the whole compass of this doc- trine, and allow, that the sentiment of belief is noth- ing but a conception more intense and steady than what attends the mere fictions of the imagination, and that this manner of conception arises from a customary conjunction of the object with something present to the memory or senses." The opinion of some critics* that Hume's doctrine ' I, p. 397. « P. 41. » P. 43. * Of. Brede, Der Vntersehied d. Lehren H., p. 50. 190 Hume's treatise and inquiet. of belief, as expressed in the Inquiry, is the natural transition to the view of the philosophers of the Scot- tish School is manifestly a product of the imagiaa- tion, rather than of the understanding. There always remained a fundamental difference between the view of Hume, and that of Reid. According to the former, the feeling or sentiment of belief, although instinctive, is derivative, arising through association and custom ; according to the latter, belief is always immediate and ultimate. "With Hume, belief is a product of the sensitive, rather than of the cogitative part of our nature ; with Reid, it has its origin in a priori intel- lectual principles. § 33. The Cause of Belief.— Since belief, as stated in the Treatise,^ consists in the force and vivacity of a perception, impressions of sense and ideas of mem- mory are believed because they have this force and vivacity in themselves. The cause of belief of reason- ing concerning matters of fact, or ideas of imagina- tion is the force and vivacity of an impression of sense or memory, and the customary transition from this impression to a related idea. Thus Hume as- serts:* "I would willingly establish it as a general maxim in the science of human nature, that when any impression hecomes present to us, it not only transports the mind to such ideas as are related to it, hut likewise communicates to them a share of its force and vivacity." Then by means of a set of experiments, he professes to show that a present im- pression and the causal relation are requisite to pro- duce belief.* The relations of resemblance and con- tiguity, although inadequate by themselves, strengthen 1 Pp. 387, 417, 448. 2 P. 399. » Pp. 402, 403. BELIEF. 101 the relation of cause and effect.. Hence, "the picture of an absent friend" enlivens tlie idea of him, because of resemblance.^ "The ceremonies of the Boman Catholic religion" inspire the devotion and quicken the fervor of "the devotees of that strange supersti- tion."^ When one is "a few miles from home," whatever relates to it touches one more nearly, be- cause of contiguity, than when one is "two hundred leagues distant."' "A man, whose memory presents him with a lively image of the Bed Sea, and the Desert, and Jerusalem^ and Galilee, can never doubt of any miraculous events, which are related either by Moses or the Evangelists."^ In like manner, want of resemblance and contiguity has an opposite effect upon belief. This is why men show a "universal careless- ness and stupidity" with regard to a future state, yet "are everywhere concerned about what may happen after their death," provided it has reference to the present world." In the Inquiry* Hume states that "sensible objects have always a greater influence on the fancy than any other, ' ' and seems to hold the same view as form- erly regarding the cause of belief of impressions.'' The cause of belief in reasoning concerning matters of fact he explains in the following manner:' "Does it happen, . . . that, when one of the objects is presented to the senses or memory, the mind is not only carried to the conception of the correlative, but reaches a steadier and stronger conception of it than what otherwise it would have been able to attain? 1 p. 400. 2 Ibid. > P. 401, * P. 410. « Pp. 412, 413. 6 P. 44. ' Of. pp. 45, 124. 8 P. 43. 192 Hume's teeatise and iNQumY. • This seems to be the ease with that belief, which arises from the relation of cause and effect. And if the case be the same with the other relations or principles of association, this may be established as a general law, which takes place in all the operations of the mind." A number of illustrations, all but one of which are taken from the Treatise, are thus given in verification of the general law.^ The position of both works, on the question of the cause of belief, is the same. § 34. Conclusion.— The results of the discussion may be summarized as follows : — 1. Belief of Impressions. In the Treatise, the highest degree of belief is attributed to impressions of sense and ideas of memory. In the Inquiry, the same view is implied, although not explicitly stated. 2. Belief of Ideas. The special subject for exam- ination, in both works, is belief of the inferred idea in reasoning concerning matters of fact. Hume de- scribes the manner of conception which constitutes belief, in the Treatise, as a superior degree of force, vivacity,'' strength, vividness,* liveliness,* firmness, solidity," intensity," intenseness,^ steadiness,* or as feeling;" in the appendix, as a feeling,^" that is, a superior force, vivacity, solidity, firmness, steadi-, ness,^^ strength, or faster hold;^^ and in the Inquiry,^? as a feeling,^^ that is, a more vivid, lively, forcible, ; firm, steady,^* or intense conception,^" "than what attends the mere fictions of the imagination. ' ' ted' I Pp. 43-45. ' P. 397. ' F. 398. « P. 399. 6 p. 406. t P. 418. ' P. 449. 8 P. 396 n. 2. » P. 403. " I, p. 555. " P. 398. 1! P. 5575 " P. 42. " Hid. 16 P. 43. BELIEF. 193 3. The Cause of Belief. The cause of belief, the author r.egards, in both the Treatise^ and Inquiry,^ as the same. Impressions of sense and ideas of mem- ory produce belief through their own inherent force and vivacity. Ideas of imagination are believed when they are related to impressions of sense or ideas of memory by means of the causal relation. In a wider sense, belief is spoken of in the earliei; work as a product of nature, and in the later, as a natural in- stinct; — custom being the cause, or the equivalent of the "product of nature," and also of the "natural instinct. ' ' While the positions of the Treatise, appendix, and Inquiry, on the subject of belief, are substantially the same, the differences of treatment are not without significance. When Hume, in the appendix, corrected the statement in the earlier, work, that "the idea of a particular object" can be varied only by increasing or diminishing its "force and vivacity," he made a step forward in psychological analysis. This is the only significance of the correction. When, in the ap- pendix and Inquiry, he substituted feeling for force and vivacity to express the differentia of belief, he recognized more fuUy than forjnerly the emotional element in belief. This is the chief significance of the change. And when, in the later writings, he employed purposely a number of terms to express this feeling, he acknowledged explicitly what he indicated only implicitly, in the earlier work, viz., that there are several forms, or kinds of belief. This is the chief significance of that "variety of terms," which he thought would seem "unphilosophical," but which : Pp. 471, 474. 2 Pp. 40, 46, 124. 13 194 Hume's treatise and inquikt. he made use of in order that his readers might "agree about the thing. ' '^ In his discussion of belief, Hume made two things clear: (1) He was fully conscious that he was on the right track; he felt that if the matter were not quite thus, it was somehow thus; (2) he was dissatisfied with his own solution. This problem is one of the very few subjects in the philos- ophy of human nature that underwent any develop- ment after it had been stated in the earlier work. But lacking experimental introspection, Hume was obliged to leave the problem of belief for his successors to unravel. 1 IV, p. 42. CHAPTER IX. PROBABILITY, NECESSITY, AND THE REASON OF ANIMALS. § 35. Probability.— In the Treatise Hume intro- duces, between the discussions on belief and necessary connection, three sections on probability, "in order to bestow" on his system "its full force and evi- dence."^ In an earlier part of the work, in accord- ance with the usual method of philosophers, he di- vided "human reason" — the objects of knowledge or reasoning — into knowledge, and probability.^ Now, in order to mark "the several degrees of evidence," as commonly understood, he thinks it more convenient "to distinguish human reason into three kinds, viz., that from knowledge, from proofs, and from proba- bilities." By knowledge, he means that "assurance arising from the comparison of ideas;" by proofs, "those arguments, which are derived from the rela- tion of cause and effect, and which are entirely free from doubt and uncertainty"; and by probability,- "that evidence, which is stiU attended with uncer- tainty."* Accordingly, the present subject of discus- sion is probability in this last or narrower sense. Probability, as thus defined, Hume divides into philo- sophical probability, and unphilosophical probability ; and philosophical probability into that of chances, and that of causes. Consequently, the topics for consideration are philosophical probability of ahance, > Pp. 423, 449, 450. « Cf. pp. 372» 43S. » P. 423. lag. 196 Hume's teeatise of human nature. philosophical probability of cause, and tmphilosoph- ical probability. They may be treated in their order. 1. The Account of Probability in the Treatise. 1. Probability of Chance. In reasonings concerning philosophical probability of chances, according to Hume, there are two points for explanation: (1) The nature of chance; (2) the effect upon the mind of a superior number of chances as influencing belief. Chance has three characteristics:'- (1) It is merely "the negation of a cause, and produces a total indif- ference in the mind"; (2) "one negation of a cause and one total indifference can never be superior or inferior to another," that is, all chances are equal; (3) among chances that are to be the foundation of reasoning, "there must always be a mixture of causes." On observing a superior number of chances, belief arises "neither by demonstration nor proia- iUity,"' but from imagination.* And the act of imagination, in conclusions concerning the probability of chances, includes three elements:* (1) A summing up, or fusion, of the favorable instances; (2) a sum- ming up of the unfavorable instances; (3) the sub- traction of the latter sum, or sums from the former. The remainder represents the probability, and the degree of assurance or strength of belief. 2. Probability of Cause. Since it is "commonly allowed by philosophers, that what the vulgar caU chance is nothing but a secret and concealed cause," Hume remarks:^ "What I have said concerning the probability of chances can serve to no other purpose) than to assist us in explaining the probability of' 1 P. 425. 2 lUd. ' Pp. 427, 428. «P. 428; of. 436. 6 p. 428. PROBABILITT, NECESSITY, ANIMAL REASON. 197 He notes that there are several Mnds of prohability of causes, and treats of the following three :^ (1) Imperfect habit, that in which the num- ber of instances necessary to produce a fixed or per- fect habit have not been experienced; (2) contrary causes, that in which the observed instances are con- trary to one another ; ^3) analogy,^ that in which the resemblance between the observed instances is inexact or incomplete. AU reasoning concerning probability of causes is derived from the same origin, viz., "the association of ideas to a present impression."^ In other words, all reasoning concerning the probability of causes, like that concerning the ■probability of chances, is based upon imagination k-ia custom. 3. Unphilosophical Probability. Probabilities of chance and of cause "are received by philosophers, and allowed to be reasonable foundations of belief and opinion." There are other sorts, however, that have not had "the good fortune to obtain the same sanction." These are classified under the term un- philosophical probability.* In unphilosophical prob- ability the evidence, and consequently the degree of belief, "diminishes by the diminution of the force and intenseness of the idea," as in the following in- stances:" "[When] the present impression is faiat and obscure; or the experience in some measure ob- literated from the memory; or the inference derived from general rules, and yet not conformable to them. ' ' All these sorts of unphilosophical probability "are derived from the same principles" as philosophical 1 p. 429. " P. 439. 3 p. 428. t p, 439. 6 P. 449. 198 Hume's tebatisb and inquiet. probability,^ and consequently do not call for further explanation. II. The Account of Probability in the Inquiry. Hume, in the Inquiry, does not make any distinction between philosophical, and unphilosophical proba- bility, and omits entirely a treatment of the latter. This does not seem to be of any special significance, however, since he said, in the Treatise, that unphilo- sophical probability is "derived from the same prin- ciples" as philosophical probability. In a foot-note" he refers to Locke's division of arguments into demon- strative and probable, and states that, in accordance with the language in common use, "we ought to divide arguments into demonstrations, proofs, and probabili- ties." Then he gives a brief account of probability of chance, and probability of cause. He asserts, as in the Treatise, that "though there be no such thing as chance in the world ; our ignorance of the real cause of any event has the same influence on the under- standing, and begets a like species of belief or opin- ion"; that is, all chances are equal, and as such have an equal influence on the mind.* Probability of chance he explains as follows:* "There is certainly a probability, which arises from a superiority of chances on one side ; and according as this superiority increases, and surpasses the opposite chances, the probability receives a proportionable increase, and begets still a higher degree of belief or assent to that side, in which we discover the superiority. ' ' And he concludes, with a more than usual degree of diffidence, that the philosophy of human nature "may, perhaps, 1 P. 439. 2 P. 47. » P. 48. * P. 47. PKOBABILITY, NECESSITY, ANIMAL EEASON. 199 in some measure," be able to accoimt for "this opera- tion" of the mind.^ Himie then declares that reason- ing concerning the probability of causes is the same as that eoncerniag the probability of chance;^ and that all the received systems of philosophy are de- fective, since none of them can explain the nature of this mental operation.' III. Conclusion. It is evident that Hume's doc- trine of probability is the same in both works. The briefer, statement, in the Inquiry, may be attributed to several causes: (1) The different circumstances under which the books were written; (2) unphilo- sophieal probability is derived from "the same prin- ciples" as philosophical probability, and consequently did not call for specific treatment a second time; (3) the account of probability given in section vi is sup- plemented by several incidental references in sections viii,* ix," and x." Brede thinks that there is an important difference between the doctrine of probability as presented in the later work, and that in the earlier. He states^ that, according to the exposition in the Inquiry, the experiences relating to the different sides do not fuse in a single picture, as they may be said to do in the Treatise, but form pictures in the mind of both pos- sibilities, and that picture with the more belief at- tached to it gives the decision directly, or immediately turns the scale. It may be admitted that there is some ground for this view, if one examines only the account > P. 48. 2 Ibid. 'P. 49. iP. 71; cf. I, p. 430. 6 P. 85; cf. I., p. 439. 6 Pp. 90, 91, 94, 105; ef. I, p. 428. ' Der Unterschied d. Lehren H., p. 40. 200 HUME'S TREATISE AND INQUIEY. given in section vi. But when notice is taken also of the references in section x, it is perceived that the position of both works is identical. In the Treatise/ a conclusion from philosophical probahiUty is the result of three processes: (1) A fusion, or union of the instances favorable to one side; (2) a fusion of the contrary instances; (3) the fusion of these two sums, or more correctly, the subtraction of the smaller sum from the greater. The remainder represents the degree of probability of the conclusion or judgment. In the Inquiry,^ the concurrence of several views in one particular event "begets immediately, by an inex- tricable contrivance of nature, the sentiment of belief, and gives that event the advantage over its antagonist, which is supported by a smaller number of views, and recurs less frequently to the mind." That is to say, in the treatment of probability, both of chance and of cause, given in the Inquiry, the third process is not explicitly designated. It may be noted, however, that, neither, is the third process mentioned in the first ex- ample of probability of causes which is given in the Treatise.* The three processes are described fully in the account of probability of chances; the first two are described in the first example of probability of causes; and then Hume remarks:* "This operation of the mind has been so fully explained in treating of the probability of chance, that I need not here en- deavor to render it more intelligible." Hence, the third process is implied, although not distinctly stated. It is stated afterwards." In the Inquiry also, in the discussion on probability, it is implied, and in the dis- 1 P. 428. ' P. 48. 3 p. 432. * P. 432. 6 p. 436. PEOBABILITT, NECESSITY, ANIMAL REASON. 201 eussion on miracles it is expressly mentioned. The author asserts:^ "AU probability, then, supposes an opposition of experiments and observations, where the one side is found to overbalance the other, and to pro- duce a degree of evidence, proportioned to the su- periority. ... In all cases, we must balance the opposite experiments, where they are opposite, and deduct the smaller number from the greater, in order to know the exact force of the superior evidence." Brede'' also alleges that the defective treatment of probability, in the Inquiry, is a result of Hume's altered view of the concept of belief. "We have al- ready shown that the doctrine of belief in the Inquiry and appendix is essentially the same as that in the Treatise.^ It is only the mode of expressing the doc- trine which is changed. And it is only necessary now to remark that, in the discussion on probability in the Inquiry, Hume again regards belief as "nothing but a firmer and stronger conception of an object than what attends the mere fictions of the imagination."* Having dealt so fully, in the Treatise, with the sub- ject of probability, the author did not think it neces- sary to repeat, in the briefer work, all he had said in the earlier. § 36. Liberty and Necessity.— Aiter the discussion of the relation of cause and effect, the order of treat- ment differs considerably in the two works. The sec- tion in the Treatise on "Eules by which to judge of Causes and Effects" is omitted in the Inquiry, and in its stead is inserted a section on "Liberty and Neces- 1 P. 90; ef. pp. 93, 94, 105. 2 Der Untersohied d. Lehren H., p. 40. » Pp. 176-182, above. < P. 48; of. p. 43. 202 HUME'S TREATISE AND INQUIRT^ sity," which was transferred from Book II of the Treatise of Human Nature. Selby-Bigge^ asserts that "the question of the employment of general rules," a subject of "great speculative as well as practical in- terest," is ignored in the Inquiry. He thinks that the omission of the section dealing with this topic is a part of Hume's policy (1) to evade a difficult gen- eral question which he has already shown his anxiety to avoid in his omission of section iii, and (2) to escape the perplexities arising from his theory of causation regarded as a natural, as well as a philo- sophical relation. The reader has already noted that the subject of "general rules" was not entirely ig- nored in the appendix/ and that Hume, in the In- quiry, still recognized the distinction between cans©* as a philosophical, and cause as a natural relation.^ Moreover, in the substituted section, the twofold defi- nition of necessity which makes "an essential part" of cause, again marks the distinction between these two forms of relation.* Furthermore, it may be ob- served that in the second edition of the Inquiry— 1751— a foot-note was added to the section on "The Reason of Animals," in order to explain "the great difference in human understandings," when reason- ing concerning "facts or causes." This note contains a series of propositions somewhat analogous to the list of general rules given in the Treatise. That these Propositions do not perfectly correspond with the "general rules," and that Hume does not again enu- merate the latter is by no means singular, since at the close of his account of this subject in the earlier work he remarked:" "Here is all the Logic I think 1 Hume's Enquiries, Introd. « P. 176. ' Of. pp. 158-159, above. * P. 79. ^ p. 468. PEOBABILITT, NECESSITY, ANIMAL REASON. 203 proper to employ in my reasoning ; and perhaps even this was not very necessary, but might have been sup- plied by the natural principles of our understand- ing." The section on "General Eules" is little more than a sequel to that on "Unphilosophieal Probabil- ity."^ Consequently, when the section on unphilo- sophieal probability was omitted in the briefer work, the omission of that on general rules followed natu- rally. An additional reason why Hume does not again enumerate the general rules is suggested by himself, when he says in the Treatise:^ "All the rules of this nature are very easy in their invention, but extremely difficult in their application." In the In- quiry, it was not at aU the author's aim to deal with questions of this character. In the Treatise of the Passions Hume begins his exposition of the wiU with a discussion on liberty and- necessity. He defines will, states that "thai)perations of external bodies are necessary, ' ' and then attempts to prove that the actiaos^mind a re "on th e same footing" a s those oTjE pier? He finds "two par- ticuIaJs/^rjelementSjjessential-to-'n-ecessity, vizi, "He" coiistanTwwiow, and the inference of the jpind"; and holds that, "wherever we discover these two factors we must acknowledge a necessity."* Hence, he con- tends that "the actions of"matter have no necessity" except constant union, and that it is "the observa- tion" of this constant union "which produces the inference." He next professes to show that "our actions have a eonstan£_uai on w ith our motives, tem- pers, and ci rcumsta nces, ' '° and that "asThe uimn 1 Of. p. 445. 2 P. 468. ' p. 181. * p. 182. « Hid. 204 Hume's treatise and inquikt. /"betwixt motives and actions has the same constancy, as that in any natural operations, so its influence on the understanding is also the same, in determining us to infer the existence of one from that of an- V other. "^ Consequently, he affirms:" "I dare be posi- tive, no one will ever endeavor to refute these reason- ings otherwise than by altering my definitions, and assigning a different meaning to the terms of cause, and/effect, and necessity, and liberty, and chance." Hiime then states three reasons for the prevalence of the doctrine of liberty :' (1) The difficulty of thinking, / after an act has been performed, that one was neces- / sitated to perform it; (2) a false sensation of the liberty of indifference; (3) the mistaken belief that libertarianism is more favorable than necessitarianism \ to the interests of morality and religion. Finally, he \ insists that his doct rine of n ecessity "is so essential to rdigion and morality, that without it there must ensue an absolute subversion of both, and that every other supposition is entirely destructive to aU laws both dwine and human."* The treatment of liberty and necessity is somewhat fuller in the Inquiry than in Book II of the Treatise of Human Nature. This fact is due chiefly to the insertion of some of the material that was omitted in the abbreviated discussion on the probability of causes," and to the develc^pmeaLof_J]iejseligiaus-asB peet of the questi on of free will.^ In spite of these diffei'SITees, tne argument"is essentially the same as that in the earlier work. The author finds, as before, that the two elements of necessity are "the constant 1 P. 185; cf. IV, p. 166. s P. 188. a Pp. 188, 189. « P. 191. 6 Of. I, p. 430; IV, p. 71. peobability>{necessity, animal reason. 205 conjumdiim-oi similar objects, and the consequent infer.£n c&^i.vom. one toTtJie other. "^ This-i5uth©-«Biy kind of^^cessity that_is_ discoverable in nature, and it exists in human craidu^ ..ectaaUy-as in the external worId~^ TEen Hume assigns reasons "why all man- kind, though they have ever, mthout hesitation, ac- knowledged jthe_jdx)ctiing of jie^sity, in their whole practice- and reasoning, have yet^discovered such a reluetajQji^_to_agbaiiwleda a„it in iM ards, and have rather shown a propensity, ia all ages, Tso profess the eontra^^oginion. ' '* And he concludes with an argu- ment to show, "that the doctrines, both of necessityT and of liberty, as above explained, are not only con-j sistent with morality and religion, but are absolutely] essential to its support."* As usual, in the Inquiry there are differences in the form of statement. The more significant of these are the following:" (1) The omission of the preliminary defirdtion of will." A definition of will was given in the earUei; work, because the subject of liberty and necessity, occurring as it does in connection with the will, was discussed under -that head. (2) The inser- tion of a more specific definition of liberty than that given formerly.'' Hume now thought that "a few intelligible definitions" would soon "put an end to the whole controversy."^ (3) The more emphatic, and the repeated assertion that aU mankind "have always been of the same opinion" with regard to the doctrine of liberty and necessity, and that "the whole con- troversy has hitherto turned merely upon words."* 1 P. 67. 2 Pp. 67-75. » P. 75. « P. 79. 6 0/. Selby-Bigge, Hum^s Enquiries, p. xviii. «II, p. 181.. I P. 78; c/=. II, p. 188. b p. 66. »Pp. 66, 67, 68, 72, 73, 75, 77, 78; of. II, pp. 181, 188, 190. 206 Hume's treatise and inquiet. (4) A nmch fuller discussion of the religious aspect of the question.^ The last change specified is by far the most impor- tant in this section of the Inquiry. Two causes are assigned— the second in a foot-note*— why "all man- kind, though they have ever, , . . acknowledged the doctrine of necessity, ia their whole practice and reasoning, have yet discovered such a reluctance to acknowledge it in words. "^ These are similar to the first two causes assigned in the earlier work. The third cause mentioned in Book II of the Treatise of Human Nature, why the doctrine of necessity has not been more generally accepted, viz., its supposed dan- gerous consequences for morality and religion, Hume now makes a subject of special treatment. He affirms that the doctrines of both liberty and necessity "as above explained, ' ' are not only consistent with moral- ity, but "are absolutely essential to its support." Liberty means "a power of act iag-e-p-^&t-^^etiirg. ac- coraing"~t6 thg"'d'ete^^^gjBaa>f-,the»^3CTdll" ;* while necessit^te"the mmtwA^cxmhm£Mo.n of similar 9b- ■iects- and th&-ConseauenL.m/ei:fiMCfi_ from one to the other."" Yet, with liberty and necessity so defined, 'aSF^Wte insisting that this doctrine is essential to i the support of morality and religion, the author pre- ' tends not "to have obviated or removed aU objec- tions" to his theory." He contends, however, that his doctrine is not worse off, in this respect, than is any other, and asserts that there are "inextricable difii- ^culties, and even contradictions" in every system. "To reconcile the indifference and contingency of > Pp. 79-84; cf. II, pp. 189-192. s P. 77. 5 P. 75. ♦ P. 78. 6 p. 67. « P. 81. PROBABILITY, NECESSITY, ANIMAL REASON. 207 hmnan actions with prescience," he declares, "or to defend absolute decrees, and yet free the Deity from being the author of sin, has been found hitherto to exceed all the power of philosophy."^ Notwith- standing some minor differences the doctrine of. lib- erty and necessity is the same in both works. There is no valid ground for the statement of Hyslop^ that, on this question, Hume is inconsistent with his doctrine of necessity as explained in the Treatise. Necessity,_.aa,.dfifined-in-Ae-Inqui-ry-,-eon-~ sistsj)^nly^iiftBe^niianrcbhjunctionTfTiEe~o^ or phenomena, and in^tha-inference-of-theTtsmd'^rom one to the other.^ This is exactly its meaning in the Treatise.* But this is not the doctrine of determinism as commonly understood. It is equivalent to tmif orm or rational conduct, and is perfectly consistent with some forms of libertarianism. In fact, it is not lib- ert arianism which Hume refutes, "but chance^ orTTE- er±y_of_m^jBfe|mce. His doctrine of necessity is the same as that of liberty of spontaneity. In Book II of the Treatise of Human Nature he asserts:" "Few are capable of distinguishing betwixt the liberty of spontaneity, as it is called in the schools, and the lib- erty of indifference; betwixt that which is opposed to violence, and that which means a negation of neces- sity and cause. The first is even the most common sense of the word; and as it is only that species of liberty, which it concerns us to preserve, our thoughts have been principally turned towards it, and have 1 P. 84. 2 Eume's Treatise of Morals, p. 33 ; cf. Grimm, Zwr Gesch. d. Erkenntnisprotlems, p. 587. » P. 79. <■ Cf. I, pp. 450-464; II, p. 182. » P. 188. ' 208 Hume's treatise and inquiry. 1 1 almost universally confounded it with the other." I Similarly, in the Inquiry, he says:^ "By liberty, then, i: we can only mean a power of actmg or not acting, \ according to the determinations of the- wUlj that is, ^ if we choose to remain at rest, we may; if we choose to move, we also may. Now this hypothetical liberty / is universally allowed to belong to every one, who is / not a prisoner and in chains. Here then is no subject i of dispute. , . . And if the definition above men- poned be admitted; liberty, when opposed to neces- /sity, not to constraint, is the same thing with chance; (which is universally allowed to have no existence." In short, Hume's doctrine of liberty and necessity was clearly in advance of the thought of his age. Far from lowering the dignity of mind, on the contrary, Hume ele vated the qualities_ a£-maltgr. In accord- ance with the tendencies of modem science, and in. conformity with the spirit of an idealistic philosophy, the author of the Treatise of Human Nature rever- ently declared:" "I do not ascribe to the will that unintelligible necessity, which is supposed to lie in matter. But I ascribe to matter, that intelligible quality, call it necessity or not, which the most rigor- ous orthodoxy does or must allow to belong to the will. I change, therefore, nothing in the received systems, with regard to the will, but only with regard to material objects," And in the later work, with equal clearness and candor, he asserted:' "But surely we ascribe nothing to the actions of the mind, but what every one does, and must readily allow of. We change no circumstance in the received orthodox sys- tem with regard to the will, but only in that with re- gard to material objects and causes. ' ' 1 Pp. 78, 79. 2 II, p. 190. » P. 80. PEOBABILITY, NECESSITY, ANIMAL REASON. 209 The examination of the doctrine of liberty and, necessity, in the Inquiry, follows very appropriately j; that of the idea of cause and effect, as one of the pra'Ci > tical applications of Hume's theory of causaticml; And it might very well have been inserted in the later work for that purpose. The author clainas, at the outset, that his argument has "novelty," that it "promises at least some decision of the controversy, and win not much disturb [the reader's] ease by any intricate or obscure reasoning."^ But although he entered upon this discussion with peace on his lips, it is much to be feared he had war in his heart. For the only important change of treatment which the subject received is the fuller development of the eth- ical and religious aspect of the question. The argu- ment, in its new form, constitutes a piece with the sections on "Miracles" and "The Practical Conse- quences of Natural Keligion. ' ' The essay on miracles Hume intended to publish in the Treatise, but was "afraid" it would give "too much offence" as the world was then disposed." The Treatise,, however, did not reach "such distinction, as even to excite a murmur, among the zealots. ' '^ Hume was determined that the Inquiry should succeed better. And it did. The author, it is true, on his return from Italy, "had the mortification to find aU England in a ferment, on account of Dr. Middleton's Free Enquiry," while his own performance "was entirely overlooked and neg- lected."* Very soon, however, he learned that the sale of his works was increasing, and that new edi- tions of them were demanded. Millar printed off a 1 p. 66. 2 Burton, Life, I, p. 63. 3 My Own Life. * Hid. 14 210 Hume's treatise and inquiet. ' second edition of the Inquiry, in 1750, but delayed publishing until the following year "because of the earthquakes."^ "Answers by Eeverends, and Right Reverends" soon came out two or three in a year, and Hume inferred from "Dr. Warburton's railing," that his books— "all but the unfortunate Treatise"— were beginning to be esteemed "in good company. "^ § 37. The Reason of Animals.— In order to confirm the truth of his system by enlarging the sphere of his experiments,' Hume devoted the last section of Part III in the Treatise to a discussion of the reason of animals. "This doctrine," he says,* "furnishes us with a Mnd of touchstone, by which we may try every system in this species of philosophy." His line of argument is as foUows: Men are conscious that, in adapting means to ends, they are guided by reason. Animals perform like actions ; therefore, they are pos- sessed of reason like that of men. Thus he asserts:^ "It is from the resemblance of external actions of animals to those we ourselves perform, that we judge their internal likewise to resemble ours ; and the same principle of reasoning, carried one step farther, wiU make us conclude that since our internal actions re- semble each other, the causes, from which they are derived, must also be resembling. ' ' It may be observed that, in an earlier part of the work, Hume recognized two kinds of reasoning, dem- onstrative, and probable ;« and that it is only the latter, probable or experiential reasoning, which he treats in the present section. He now distinguishes between those actions of animals "which are of a vulgar 1 Burton, Ufe, I, p. 300. » My Own Life, a p. 468. * !"• 469. 5 Ibid. e I, pp. 373, 376. PEOBABILITT, NECESSITY, ANIMAL EEASON. 211 nature," and "those more extraordinary instances of sagacity," known as instinctive acts. The former actions proceed from reasoning similar to "that which appears in human nature," that is, from a present impression of sense or memory and the observation of the constant conjunction of similar objects in past experience.^ The latter actions Hume does not at- tempt to explain, though he seems to regard them as closely related to the former. For "reason," he de- clares, "is nothing but a wonderful and unintelligible instinct in our souls. ' ' True, it is an instinct which arises from "past observation and experience," as contrasted with instinct proper which arises imme- diately from nature. But no one can explain why nature should produce one kind of instinct in this way through habit, and produce another kind of in- stinct immediately and directly.^ The philosophy of human nature, therefore, ex- plains the reasoning of men and of animals on the same principle. Moreover, according to the author, the reasoning of men and animals cannot be satisfac- torily explained otherwise than on a single principle. For if on the one hand, the reasoning process, or the reasoning faculty in man is of such a profound or abstract nature that animals cannot be regarded as possessing it, then neither can children nor some un- educated persons be thought to have it. And if on the other hand, reason is attributed to these latter, it cannot logically be denied to many species of animals. The only kind of reasoning, however, that animals are capable of performing is inference, or transition from a present impression of sense or memory to a related 1 P. 470. « P. 471. 212 Hume's treatise and iNQiriET. idea by means of association and custom.^ And this is precisely that in which Hume professes to have al- ready shown the reasoning of men concerning matters of fact to consist. Here then he claims to have 'not merely "a strong confirmation," but rather "an in- vincible proof" of the truth of his system.^ In the Inquiry also, the author hopes that the ex- amination of the reason of animals "will serve to con- firm" his "former observations." Any theory which explains "the operations of the understanding, or the origin and connection of the passions in man, ' ' will acquire additional authority if it "is requisite to explain the same phenomena in all other animals."^ He regards animals as performing two kinds of acts : those learned by experience, and those prompted by instinct* The former proceed from education and custom; thus Hume remarks:" "It is custom alone, which engages animals, from every object, that strikes their senses, to infer its usual attendant, and carries their imagination, from the appearance of the one, to conceive the other, in that particular, maimer, which we denominate belief." And he adds: "No other explication can be given of this operation, in all the higher, as well as lower classes of sensitive beings, which fall under our notice and observation." On the other hand, instincts are derived from "the orig- inal hand of nature." Of them no explanation is offered. Hume still speaks of experimental reasoning as "a species of instinct." It is different of course from instinct proper, in that it arises from experience and custom; while instinct proper, coming from the original hand of nature, is capable of little or no im- provement. iP. 471. 2 /Bid. »P. 85. *Pp. 85, 88. = P. 87. PEOBABILITT, NECESSITY, ANIMAL REASON. 213 Besides a slight change in the order of discussion, the only difference of note, in the Inquiry, is the explicit recognition that there are two kinds of reason- ing, viz., reasoning concerning ideas — "comparisons of ideas,"— and reasoning concerning matters of fact —"experimental reasoning."^ Eelations or compari- sons of ideas Hume regards as "the proper objects of [man's] intellectual faculties."" And he asserts that animals do not reason in this sense of the term. Although the distinction here drawn, between demon- strative and probable reasoning, is not made in the section on the reason of animals in the Treatise, it was made repeatedly in other parts of the work.° Even in the section of the Treatise under discussion, Hume implies that animals do not reason in the nar- rower meaning of the word, when he states that "they can never by any arguments form a general conclu- sion, that those objects, of which they have had no experience, resemble those of which they have."* Notwithstanding some modifications, therefore, in the manner of treatment, the standpoint of the later work, on this question, does not differ in any essential respect from that of the earlier. Huxley contends that, while Hume seemed to re- gard the reasoning of men and of animals as being different ia kind, he reaUy held that it is only different in degree. "It wiU be observed," he says,"' "that Hume appears to contrast the 'iuference of the ani- mal' with the 'process of argument or reasoning ia man.' But it would be a complete misapprehension 1 Pp. 86, 88. « P. 88. 3 Of. pp. 372, 373, 375, 376, 390, 472, 473. * P. 471. 'Bume, p. 107; cf. Grrimm, Zur. Qesch. d. Erkenntnisproi- lems, p. 557. 214 Hume's treatise and inquiet. of his intention, if we were to suppose, that he thereby means to imply that there is any real difference be- tween the two processes." If one examines only the exposition of the Treatise, one may find some groimd for, Huxley's assertion. In the earlier work, the author states that no truth appears to him to be more evident "than that beasts are endowed with thought and reasoning, as well as men. ' '^ When one turns to the Inquiry, however, one discovers that Hume con- trasts the "inference of the animal" with the "process of argument" in man, and denies that animals reason in the latter sense. As has just been pointed out, he recognized two Mnds of reasoning, viz., reasoning concerning ideas, and reasoning concerning matters of fact. "Relations or comparisons of ideas, . . . are the proper objects of [man's] intellectual facul- ties. ' ' But arguments of this nature ' ' lie too abstruse for the observation of [animals'] imperfect under- standings." Huxley did not seem to take sufficient account of language as a factor in the reasoning process. It may be remarked, in conclusion, that Hume's discussion on the reason of animals, except in so far as it prepared the way for the science of comparative psychology, is of exceedingly little value. It throws no light whatever on the question which is much agitated at the present day, viz.. Do animals reason? The reasoning processes which Hume attributes to animals are merely instances of "association by con- tiguity." The real problem is, whether the mental processes of animals ever take the form of "associa- tion by similarity"?— a problem which, despite the 1 P. 469. PEOBABILITy, NECESSITY, ANIMAL REASON. 215 valuable and Interesting work of Mills, Thorndike, and other enthusiastic investigators iu this field, is stiU almost as far from a sa,tisfactory solution as it ever was. CHAPTER X. THE IDEA OF MATEEIAL SUBSTANCE, AND OF AN EXTERNAL WOELD. § 38. The Idea of Material Substance.— Ues-pecting the idea of material substance Berkeley stands in a relation to Locke similar to that in which Fichte stands to Kant. As Fichte rejected the ding-an-sich as the ground of phenomena, so did Berkeley the un- known something as the ground of material qualities. Hume merely followed in the track of Berkeley. His doctrine of substance, as presented in the Treatise, is well known. It is stated briefly in Part I, and is an immediate consequence of the fundamental prin- ciples of the philosophy of human nature. Since all ideas are derived from impressions ; and since impres- sions are of two kinds, sensation, and reflection; the idea of substance must be derived from an impression of sensation, or of reflection. If it be derived from an impression of sensation, it must be a color, sound, taste, etc.; and if it be derived from an impression of reflection, it must be a passion, or an emotion.^ Bach of these alternatives is absurd. Hence, the idea of substance, if taken to be something other than that of a group of qualities, is a fiction. It is a complex idea resultiag from the operation of the laws of asso- ciation,^ and is "nothing but a collection of simple ideas, " or a group of qualities with a particular name assigned to them.' 1 P. 324. ' P. 321. 3 P. 324. 216 MATERIAL SUBSTANCE AND EXTERNAL WORLD. 217 In part IV, in accordance with Ms usual mode of procedure in the earlier work, Hume gives an account of the genesis of the idea of substance.^ On ohserving the successive qualities of an object through a brief lapse of time, when the succession is smooth and gradual the mind is carried insensibly along by an easy transition, and does not perceive the change any more than it would did it contemplate a single un- changeable object. In this way arises the idea of identity. But when the smooth succession of quali- ties is hindered, either by a break ia the sequence, or by a rapid change in the object, the natural progress of the thought is interrupted. Then there arises the idea of diversity. And as the ideas of identity and diversity are contrary to each other, the imagination, in order to solve the contradiction, feigns an unknown something which is supposed to remain invariably the same throughout the change of qualities. This un- known something is substance. It is a fiction postu- lated by the mind ia order to unite the various quali- ties of objects or impressions, and is postulated ac- cording to natural laws. The fiction of an underlying substance, however, is whoUy unnecessary, because qualities may exist by themselves. "Every quality being a distinct thing from another," says Hume,^ "may be conceived to exist apart, and may exist apart, not only from every other quality, but from that unintelligible chimera of a substance." Hence there is a twofold argument against the validity of the idea (1) It is unnecessary; (2) it is impossible. In the Inquiry there is no discussion of the idea of substance. As has already been mentioned,' the treat- 1 Pp. 606, 507. " p. 508. > Pp. 80, 81. 218 HUME'S TREATISE AND INQXJIET. ment of complex ideas— substances, modes, and rela- tions—is omitted. There are some incidental refer- ences, however, which have a bearing upon the idea of material substance, and which may be examined briefly. Hume asserts that the qualities of "solidity, extension," and "motion," are "aU complete in themselves" ;^ and that these qualities— the primary- are on the same basis as are the secondary." Conse- quently, it may be concluded that the idea of sub- stance, if understood as anything different from the idea of a group of qualities, is unnecessary. Again, the criterion of the validity of ideas remains the same as it was in the Treatise.^ Hence, it may be inferred that the idea is impossible. According to the logical standpoint of the Inquiry, therefore, the idea of sub- stance is both unnecessary and impossible, as it had been declared to be in the Treatise. In confirmation of this conclusion is the following passage from a letter of Hume to Henry Home in 1746:* "As to the idea of substance, I must own, that as it has no access to the mind by any of our senses or feelings, it has always appeared to me to be nothing but an imaginary centre of union amongst the different and variable qualities that are to be found in every piece of matter." It may be inferred, therefore, that Hume's view of material substance was the same when he wrote the In- quiry as when he composed the Treatise. The prem- ises remain the same, the conclusion only is omitted. For this omission several explanations have been of- 1 P. 53. 2 Pp. 125-127. » Pp. 14, 16, 17, 52. *Tytler, Memoirs of H. H. of Kames, I, p. 124; cf. Long, Veber Hume's Lehre v. d. Ideen u. d. Buistance, pp. 34, 36 n. PEOBABILITY, NECESSITY, ANIMAL REASON. 219 f ered. It is a common opinion that, shortly after the publication of the Treatise, Hume became conscious that his principle of connection among ideas was very- defective. Thereupon his former account of fictitious ideas would appear to him to be unsatisfactory. And as he was unable to devise a more plausible process of their derivation, he would naturally avoid a discus- sion of the subject in the Inquiry. There does not appear to be much weight in this argument. Hume recognized that his principle of connection among ideas, when used to explain the fiction of self or of personal identity, was very defective, but not when used to explain the idea of cause and effect or of material substance. Selby-Bigge^ asserts that "sub- stance is passed over," in the later work, "probably both from the difficulty of the subject, and because in the Enquiry Hume is not nearly so anxious to show that the fundamental popular conceptions are ficti- tious." The former supposition appears to be groundless, inasmuch as the doctrine of substance is not any more difficult of treatment than is that of causation. But the latter statement undoubtedly contains an element of truth; for the Inquiry was written under different circumstances, and for a dif- ferent class of readers than was the Treatise. In the later work, Hume desired to present his theory of knowledge, or at least the more important parts of it, in a brief and popular manner. It is not surprising, therefore, that the discussion on substance was omit- ted. Moreover, the division of complex ideas into substances, modes, and relations was an inheritance ijffiMjie's Enquiries, p. xiii. 220 hume's treatise and inquieT. from Locke. Hume was not so much dependent on Locke when he wrote the Inquiry as when he wrote the Treatise.^ Consequently, the omission of this classification of ideas, and of the treatment of the particular topics included under it may have been due in part to that circumstance. § 39. The Idea of an External World.— Id. the last section of Part II of the Treatise, Hume discusses the ideas of existence and external existence, as a prepara- tion for the examination of knowledge and probability. He states that the idea of existence is "the very same with the idea of what we conceive to be existent,"* and concludes:' "Since nothing is ever present to the mind but perceptions, and since all ideas are derived from something antecedently present to the mind; it follows, that it is impossible for us so much as to con- ceive or form an idea of any thing specifically dif- ferent from ideas and impressions." This discussion of external existence is only introductory. The full treatment of the subject is given in Part IV, where the question of the existence of an external world is dealt with under two heads: (1) The vulgar hypoth- esis; and (2) the philosophical. I. The Vulgar Hypothesis. The vulgar hypothesis of external existence is the assumption that sense per- ceptions are external material objects. "It is certain," says Hume,* "that almost aU mankind, and even philosophers themselves, for the greater part of their lives, take their perceptions to be their only objects, and suppose, that the very being, which is intimately present to the miad, is the real body or material exist- 1 Cf. 1, pp. 308, 342; IV, p. 17 n. 1. " P. 370. > P. 371. * P. 495; of. p. 491. MATERIAL SXJBSTANCE AND EXTERNAL WORLD. 221 ence." And since it is vain to ask,. Whether there be body or not ? as this is a point which must always be taken for granted, nature not having left it a matter of choice, the question which he raises now is, "What causes induce us to believe ia the existence of body ? ' ' In answer, he professes to show:^ (1) How the vulgar hypothesis of continued and distinct or independent, existence arises; (2) why this kind of existence is attended with belief? Upon the elaborate process of derivation and explanation it is unnecessary to enter. It is sufficient to note the following characteristic features of the discussion in the Treatise : (1) "Every impression, external and internal, passions, affections, sensations, pains and pleasures, are originally on the same footing.'"' (2) The idea of continued and dis- tinct existence, or of the external existence of per- ceptions is derived neither from the senses,* nor from reason,* but from the imagination." Objects have a certain coherence as they appear to the senses. And the imagination, "when set into any train of thinking, is apt to continue, even when its object fails it, and like a galley put in motion by the oarSj carries on its course, without any new impulse." In this manner, from the constancy and coherence of perceptions arises the idea of their continued and distinct or inde- pendent existence. (3) Belief in the external exist- ence of perceptions arises through the effect upon the imagination of the force and vivacity of the successive resembling perceptions,' in accordance with Hume's general theory." i.P. 478. 8 P. 480; cf. p. 371. ^ Pp. 478-482. * P. 483. 6 Pp. 484-495. s Pp. 496, 497. ' Of. pp. 182, 183, above. 222 humb's treatise and inquibt. In the first part of section xii of the Inquiry, there are a few references to the existence of an external world. The distinction between the vulgar hypothesis of external existence, and the philosophical, is not explicitly made in these terms ; but it is clear that the distinction which is here recognized, is the same as that made in the earlier wort.^ Concerning the vul- gar hypothesis, Hume's position may be represented as follows: (1) The primary and secondary qualities of objects are on the same basis, and are only per- ceptions in the mind.'' (2) All men, and even ani- mals, "are carried, by a natural iastinct or preposses- sion, to repose faith in their senses," and to suppose an external universe to exist; and "when men follow this blind and powerful instinct of nature, they al- ways suppose the very images, presented by the senses, to be the external objectSi"* (3) An explanation of belief is not given, but the doctrine of belief in the Inquiry is essentially the same as that in the Treatise,* viz., belief consists in the force, vivacity, steadiness, etc., of an impression or idea."* Consequently, it may be concluded that, on the question of the vulgar hy- pothesis, the position of both works is practically the same. The only significant difference consists in omissions; the treatment in the earlier work being detailed and explicit, but in the later, brief, to a large extent indeed only implied. It may be observed that Brede professes to find, in the Inquiry, an important difference on this question. He asserts:* "[The vulgar hypothesis of an external ' P. 125. 2 Pp„ 124, 125. 8 p. 124. * Of. pp. 177-182, above. s Pp. 40, 43. 5 Der UntersoMed d. Leh/ren M., pp. 47, 48. MATERIAL StJBSTANCB AND EXTERNAL WORLD. 223 world] is here based solely on a supposed deception of the senses, an assumption which, in the Treatise, was directly rejected." The difference here pointed out is only one of the meaning of words. Hume is not precise in his use of language. He uses imagination in several different senses ; — as contrasted with mem- ory,^ as opposed to reason,'' and yet as equivalent to reason or the understanding,' as synonymous with sense,* and as synonymous with nature or instinct.'' In the account, ia the later work, he does not explicitly state that the vulgar hypothesis arises through an illusion of the senses, nor in any manner different from that in which he regarded it as originating in the earlier. He says it arises from "a natural in- sttact."° In the Treatise he said it arises from na- ture, instinct, or imagination.'' True, in the Inquiry, Hume admits that, on this topic, there is a conflict between the senses and reason, as if to imply that the vulgar hypothesis is derived from the senses, and the philosophical hypothesis from the reason.^ But in a similar manner, in the earlier work, he admitted the existence of a conflict, on the same subject.* Of course it is admitted that Hume, in the Inquiry, seems to regard the idea of external existence as being de- rived through the senses.^" But it must not be over- looked that, in the Treatise, he uses "senses" as a convenient term for imagination, or the principles that give rise to the vulgar hypothesis. Thus he as- serts :^^ "There is a direct and total opposition betwixt 1 1, p. 317. » I, pp. 416 n., 502. s I, p. 547; cf. p. 505. * I, p. 504. 5 i^ pp. 478, 501, 502. « Pp. 124, 127. I Pp. 478, 501, 502. 8 pp. 125, 127. = P. 504. i» P. 124. " P. 516. 224 Hume's treatise and inquiet. our reason and our senses ; or more properly speaking, betwixt those conclusions we form from cause and effect, and those that persuade us of the contuiued and independent existence of body." It is obvious, therefore, that since no real diversity of view exists on this question, the briefer treatment in the later work is the cause of the apparent diversity of state- ment. II. The Philosophical Hypothesis. The philosoph- ical hypothesis of an external world is the assumption of "the double existence of perceptions and objects," of perceptions in the mind, and of external objects corresponding to them.^ According to the account in the Treatise, the philosophical hypothesis arises in the following manner: after arriving at the vulgar hypothesis, and acquiring a belief that perceptions are external objects, if one makes a few experiments, or reasons about the matter, one immediately perceives that the existence of perceptions is interrupted, and that "the doctrine of the independent existence" of sensible perceptions "is contrary to the plainest ex- perience."'' Then, in order, to solve the contradic- tion, the philosophers invent the hypothesis of "the double existence of perceptions and objects," and suppose the former "to be interrupted, and perish- ing," but the latter "to be uninterrupted, and to observe a continued existence and identity."' The philosophical hypothesis, however, in the author's estimation, "is only a palliative remedy," and "con- tains aU the difficulties of the vulgar system, as weU as some others that are peculiar to itself." It has "no primary recommendation either to reason or the 1 1, p. 499. ! p. 498. 3 P. 499. MATERIAL SUBSTANCE AND EXTERNAL WORLD. 225 imagination," but "acquires all its influence on the imagination" from the vulgar hypothesis.^ And Hume'' concludes: "This skeptical doubt, both with respect to reason and the senses, is a malady, which can never be radically cured, . . . Carelessness and inattention alone can afford us any remedy." On these qualities of miad he relies with a degree of assurance not surpassed by the confidence placed in the priuciples of common sense by his illustrious countrymen of the Scottish School.^ In addition to the argument in the second section, Hume claims to show, in the fourth, that if the funda- mental principle of modern philosophy — viz., the subjectivity of the secondary qualities of objects,— be admitted, there is no ground for attributing ob- jectivity to the primary qualities, and consequently, no possibility of arriving at a knowledge of external existence. Thus he asserts:* "I believe many objec- tions might be made to this system [modern philos- ophy] : But at present I shall confine myself to one, which is in my opinion very decisive. I assert, that instead of explaining the operations of external ob- jects by its means, we utterly annihilate all these objects, and reduce ourselves to the opinion of the most extravagant skepticism concerning them. If colors, sounds, tastes, and smells be merely perceptions [and this he has repeatedly affirmed] ,° nothing we can conceive is possessed of a real, continued, and independent existence ; not even motion, extension and solidity, which are the primary qualities chiefly in- sisted on." Then he resolves the primary qualities 1 Pp. 499, 500. ' P. 505. 3 Of. Hid. * P. 513. s Pp. 371, 481, 482, 511, 512, 526. 15 226 Hume's treatise and inquiet. into secondary: "The idea of motion depends on that of extension, and the idea of extension on that of solidity." Solidity is inconceivable alone, because it depends on other secondary qualities. "And upon the whole," says Hume,^ "[we] must conclude, that after the exclusion of colors, sounds, heat and cold from the rank of external existences, there remains nothing, which can afford us a just and constituent idea of body." In-Part IV, he also refers to Part II, and claims that there he has already shown "the no^ tion of external existence, when taken for something specifically different from our perceptions," to be "an absurdity."" In the twelfth section of the Inquiry, Hume gives a brief account of the philosophical hypothesis of ex- ternal existence. After referring to the universal belief of mankind in the existence of an external world, a belief that "the very images, presented by the senses," are "the external objects," he proceeds:^ "But this universal and primary opinion 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 conveyed, without being able to produce any imme- diate intercourse between the mind and the object. The table, which we see, seems to diminish, as we re- move farther from it : But the real table, which exists independently of us, suffers no alteration: It was, therefore, nothing but its image, which was present to the mind. These are the obvious dictates of reason ; and no man, who reflects, ever doubted, that the ex- 1 P. 514. « P. 479. ' Pp. 124, 125. MATERIAL SUBSTANCE AND EXTERNAL WORLD. 227 istences, whicli we consider, when we say, this horse and that tree, are nothing but perceptions ia the mind, and fleeting copies or representations of other exist- ences, which remain uniform and independent. ' ' But what existences are those that are thought to remain "uniform and independent"? Hume replies:^ "So far, then, are we necessitated by reasoning to con- tradict or depart from the primary instincts of nature, and to embrace a new system with regard to the evi- dence of our senses. But here philosophy finds her- self extremely embarrassed, when she would justify this new system, and obviate the cavils and objections of the skeptics. ... To justify this pretended philo- sophical system, by a chain of clear and convincing arguments, or even any appearance of argument, ex- ceeds the power of all human capacity." In the Inquiry also, the distinction between the primary and secondary qualities of objects is referred to in a manner similar to that in the Treatise. "It is universally allowed by modem inquirers," says Hume,^ "that all the sensible qualities of objects, such as hard, soft, hot, cold, white, black, etc., are merely secondary, and exist not in the objects themselves, but are perceptions of the mind, without any external archetype or model, which they represent. If this be allowed, with regard to secondary qualities, it must also follow, with regard to the supposed primary qualities of extension and solidity; nor can the latter be any more entitled to that denomination than the former. The idea of extension is entirely acquired from the senses of sight and feeling; and if aU the qualities, perceived by the senses, be in the mind I p. 125. « Pp. 126, 127. 228 HUME'S TREATISE AND ESTQUIRT. [and this is what he maintains],^ not in the object, the same conclusion must reach the idea of extension, which is wholly dependent on the sensible ideas or, the ideas of secondary qualities. Nothing can save us from this conclusion, but the asserting, that the ideas of those primary qualities are attained by Ab- straction; an opinion, which, if we examine it accu- rately, we shall find to be unintelligible, and even absurd. ' ' On the question of the philosophical hypothesis of external existence, therefore, the standpoint of both works is identical. As in almost every other instance, however, the mode of treatment is different. The account in the Inquiry is so brief that one learns its full significance only by reading it in connection with the exposition in the Treatise. The tone also is less dogmatic, and the manner of expression more careful. These differences are only such as one would natu- rally expect, if one takes into account Hume's tem- perament, and the circumstances under which the respective books were written.^ § 40. Conclusion.— The chief points in the chapter may now be brought together. 1. The Idea of Material Substance. In the Treatise, Hume professed to show that the idea of material substance can be derived neither from sensation, nor from reflection. It is, therefore a fiction, produced by the imagination. The idea of identity arises on viewing a series of successive resembling perceptions of the same object. This idea, when the series is broken, gives place to that of diversity. Then, to • Of. pp. 13-17, 61, 124, 125, 126. 2 Cf. Burton, Life, 1, pp. 63, 98. MATERIAL SUBSTANCE AND EXTERNAL WORLD. 229 solve the contradiction, the imagination posits the idea of substance, as the ground of union for the different perceptions. In a letter to Home, ia 1746, Hume expressed the same view as that in the Treatise. Consequently, it may be concluded that his position was unchanged when he wr,ote the Inquiry. In the later work, the discussion is omitted. The cause for this omission is not positively known, but was prob- ably desire for brevity, for simplicity, or for pop- ularity. 2. The Idea of an External "World. According to the account in the Treatise, the mind knows only per- ceptions.^ To these perceptions is attributed an in- dependent existence, through the influence of imag- ination or natural instinct.^ Reflection shows that this belief is contrary to reason.* To solve the con- tradiction the mind invents the hypothesis of "the double existence of perceptions and objects."* But this assumption is contrary to natural instinct, and besides, cannot be justified by reason.^ ' ' This philo- sophical system," Hume asserts,® "is the monstrous offspring of two principles, which are contrary to each other, which are both at once embraced by the mind, and which are unable mutually to destroy each other." Then with his accustomed frankness, he gives expression to his own feeling in the following words -^ "Having thus given an account of all the systems 1 I, pp. 371, 483, 487, 501, 518; IV, pp. 61, 124, 126. 2 I, pp. 478, 484, 491, 493, 495, 501; IV, pp. 124, 125. 3 I, pp. 498, 501, 504; IV, pp. 124, 125, 127. * I, pp. 499, 501, 502; IV, pp. 125-127. '■ I, p. 502; cf. rV, p. 126. ' I, p. 504; cf. IV, p. 126. 230 Hume's treatise and inquibt. both popular and philosophical, with regard to ex- ternal existences, I cannot forbear giving vent to a certain sentiment, which arises upon reviewing those systems. I began this subject with premising, that we ought to have an implicit faith in our senses, and that this would be the conclusion, I should draw from the whole of my reasoning. But to be ingenuous, I feel myself at present of a quite contrary sentiment, and am more inclined to repose no faith at all in my i senses, or rather imagination, than to place in it such an implicit confidence." The position of the Inquiry on the question of the existence of an external world is similar to that of the Treatise,^ except in one respect. In the earlier work, when Hume professes to have shown how belief in external existence arises from the force and vivacity of resembling perceptions, and that the mind knows nothing specifically different from perceptions, he appears as the expounder and advocate of a system of skepticism. In the later work, he omits an account of the derivation of belief in external existence, and appears, not as the exponent of a system, but rather as a dialectitian. In the Inquiry, he is a critic of the prevailing systems; in the Treatise, he is not merely a critic, but also the expounder of a new system. While this constructive element gives the earlier work an air of positiveness ; from another point of view, it only serves to make the skepticism more pronounced. Hence, it is easy for any one to put forward the claim that either book is more negative, or is more positive than the other. It is most probable, however, that I Of. Bain, Mental and Moral Science, p. 205 j Burton, Life, I, pp. 274, 337. MATERIAL SXJBSTANCE AND EXTERNAL WORLD. 231 the omissions, in the Inquiry, were due entirely to adventitious circumstances, and not to any real change of view on the part of the author. Hume's philosophical position on the question of the existence of an external world is still a matter of dispute. On the one hand, it is universally admitted that he affirmed a belief in external existence ; and on the other, it is generally recognized that he denied the possibility of any real knowledge of external exist- ence, as something different from perceptions. But between these two extremes lie many intermediate views. Jodl^ states that, according to Hume, nothing remains of the ideas of matter and external existence but, at most, an unknown, inexplicable something as the cause of perceptions, and which the skeptic will not envy any one. Windelband^ affirms that the ex- istence of a corporeal world is to be assumed as at most only probable. Falckenberg' declares that Hume does not follow Berkeley to the extent of denying ex- ternal reaUty. Erdmann asserts:* "Hume never doubted, what was regarded beyond everything else as doubtful by the skeptics of antiquity, the existence of what we perceive." Brown" holds that, on this question, Hume and Eeid are in accord. One cannot prove by reason the existence of an external world, but one believes. Hume emphasizes the first position, and Eeid the second; this is all the difference be- 1 Leben und Phil. D. E., p. 75. 2 Ctesch. d. n. Phil., I, p. 319. ' History of Modem Philosophy, p. 221. * History of Philosophy, II, p. 130. 6 Lectures on the Philosophy of Mind, II, p. 89. 232 Hume's treatise and inquiet. tween them. Webb states:^ "So far is Hume from dogmatically denying the existence of an external world in external space tliat lie systematically assumes it." And Reid declares:^ "Wlien we find Bishop Berkeley and Mr. Hume, the acutest metaphysicians of the age, maintaining that there is no such thing as matter in the universe— . . . when we find the last maintaining that there is neither body nor mind— ... we may be apt to think the whole to be only a dream of fanciful men, who have entangled themselves in cobwebs spun out of their own brain." It is natural to expect that a question on which there is so much diversity of opinion is extremely difficult accurately to determine. Such is indeed the case. And what the opinion of any individual writer may be, with regard to the problem, seems to be a matter of extremely little moment ; for it is reasonable to suppose that, in the future, as in the past, among Hume's interpreters, sentiment rather than reason will give the casting vote on this question. Such con- sideration, however, wiU never deter the philosopher from offering a new solution. Hume's position on the question of the existence of an external world appears to be the following: Accepting the existence of perceptions— a form of reality which no one ever doubted, — he professed to explain, both according to the vulgar hypothesis, and according to the philo- sophical, how, through certain qualities of the imag- ination, belief in an external world arises. But he 1 Veil of Isis, p. 121 ; cf. Hunt, Oontemporwry Review, Vol. XI, p. 83; Papillon, Bistoire de la Philosophie Moderne, II, p. 19; Dhl, Humes Stellung in d. engUschen PMl., 1, p. 13; Bain, Mental and Moral Science, p. 207. s Works, I, p. 242. MATERIAL SUBSTANCE AND EXTERNAL WORLD. 233 also claimed to show that both these beliefs are irra- tional and unjustifiable; the first being contrary to reason, the second contrary to natural instinct, and each contradictory to the other. Nevertheless, he as- serted that the matter has not been left to choice, that the mind, in accordance with, the fundamental prin- ciples of human nature, still continues to reason about these contradictory alternatives, and to believe in the existence of an external world. Such existence, how- ever, lies outside the sphere of knowledge, and hence is both unknown and unknowable. The final outcome, therefore, of Hume's reasoning on this question is philosophical or theoretical skepticism. But our phi- losopher is not a dogmatist; whether there is an ex- ternal world or not does not trouble him in the least. Nature is able enough to take care of herself; and nature necessitates an irresistable belief in external existence. This is sufficient for, the needs of every- day life. Hence, actually, he is a positivist. Theoretically, therefore, Hume is a skeptic; prac- tically, he is a realist ; and actually, he is a positivist. Consequently, it is not surprising that, notwithstand- ing his positivism and skepticism, he frequently im- plies, both in the Treatise and in the Inquiry, the existence of an external world as unhesitatingly as if he were a philosopher of the Scottish School.^ The concluding passage of his treatment of the question is characteristic of the author, and significant of his true position. "Carelessness and inattention alone," he says," can afford us any remedy [against the malady of skeptical doubt]. For this reason I rely 1 Cf. 1, pp. 317, 342, 461, 462, 549; IV, pp. 23, 25, 28, 46, 47. a I, p. 505. 234 Hume's treatise and inquiry.. entirely upon them ; and take it for granted, whatever may be the reader's opinion at this present moment, that an hour hence he will be persuaded there is both an external and internal world ; and going upon that supposition, I intend to examine some general systems both ancient and modern, . . , before I proceed to a more particular inquiry concerning our impres- sions." t^ The foundation stone of metaphysics has often be- come the Achilles' heel. Such it became for Hume. The vulnerable point in his philosophical system, the source of his gravest errors as well as the cause of his greatest difficulties, is his inadequate conception of the self. He failed to realize that self-knowledge is knowledge of something permanent and substantial. This knowledge is the key to aU knowledge, since the microcosm is an organic part of the macrocosm. As there is real knowledge of the self ,> so real knowledge is inherently possible of all other things, in so far as they partake of the nature of self. The transition from knowledge of the self to knowledge of other selves, and even to knowledge of external things, is clearly intelligible as weU as perfectly natural. CHAPTER XI. SPIRITUAL SUBSTANCE, THE SELF, AND PERSONAL IDENTITY. § 41. The Idea of Spiritual Substance. — The ideas of spiritual substance, self, and personal identity are so closely related to one another, that it is extremely difficult to discuss them separately. It seems that, for Hume, spiritual substance is equivalent to mind in general, self is the concrete or individual mind, and personal identity is a quality or supposed quality of self, viz., its permanence and invariability. With this explanation, the ideas of spiritual substance, self, and personal identity wiU be treated in their order. Sidney Smith once humorously remarked: "Bishop Berkeley destroyed the world ia one volume octavo, and nothing remained after his time but mind, which experienced a similar fate from Mr. Hume in 1739." Hume's criticism of spiritual substance is merely an application of Berkeley's principle regarding material substance. As Berkeley showed that Locke's idea oi material substance, according to his own presupposi- tions, was a fiction, so Hume showed, in like manner, that his idea of spiritual substance is a fiction also. The doctrine of spiritual substance, as explained in the Treatise, is strictly analogous to that of material substance. There is no impression of substance, either of material, or of spiritual ; consequently, there is no valid idea either of material, or of spiritual 235 236 Hume's treatise and inqxhet, substance.^ An idea of spiritual substance is not needed in the philosophy of human nature, any more than is required an idea of material substance. For, thus Hume reasons:^ "Whatever is clearly conceived may exists and whatever is clearly conceived, after any manner, may exist after the same manner. This is one principle, which has been already aelmowl- edged. Again, every thing, which is different, is distinguishable, and every thing which is distinguish- able, is separable by the imagination. This is an- other, principle. My conclusion from both is, that since aU our perceptions are different from each other, and from every thing else in the universe, they are also distinct and separable, and may be considered as separately existent, and may exist separately, and have no need of any thing else to support their exist- ence." The genesis of the fictitious idea of spiritual substance Hume likewise attempts to explain in the same way as he explained the origin of the idea of material substance.* In the Inquiry, there is no treatment of spiritual substance. Hume's last word on this subject is in the appendix. Here spiritual substance and self are treated together, as if they meant the same thing; otherwise, the import of the discussion is similar to that of the exposition in the Treatise. Hume re- marks:* "Philosophers begin to be reconciled to the principle, that we have no idea of external substance, distinct from the idea of particular qualities. This must pave the way for a like principle with regard to ' P. 517. 2 p. 518. 3 Pp. 535, 536. « I, p. 559. SPIRITUAL SUBSTANCE, PERSONAL IDENTITY. 237 the mindi that we have no notion of it, distinct from the particular perceptions. ' ' Again, he says :^ ' ' When we talk of self or substance, we must have an idea annexed to these terms, otherwise they are altogether unintelligible. Every idea is derived from precedent impressions; and we have no impression of self or substance, as something simple or individual. We have, therefore, no idea of them in that sense." Finally, the idea of spiritual substance is not neces- sary; for he asserts:" "Whatever is distinct, is dis- tinguishable ; and whatever is distinguishable, is sep- arable by the thought or imagination. All perceptions are distinct. They are, therefore, distinguishable, and separable, and may be conceived as separately existent, and may exist separately, without any contradiction or absurdity." It is manifest that the doctrine of spiritual substance is exactly the same in the appendix as in the Treatise. Consequently, there is a strong probability that when Hume wrote the Inquiry he had not changed his view, in any important respect, upon this question.* The reasons for omitting the discus- sion, in the later work, were in large measure similar to those for omitting a specific treatment of material substance.* § 42. The Idea of Self.— The tacit implication of the existence of the self Hume, no doubt, found help- ful when explaining belief, both in the relation of cause and effect, and in the existence of an external 1 I, p. 558. ' nid. 3 Cf. Bain, Mental cmd Moral Science, p. 205 ; Windelband, aesoh. d. n. Phil., p. 324. *Cf. pp. 208-209, above. 238 Hume's treatise and inquiet. world. But having explained these doctrines, at least to his own satisfaction, he was in a position, at the end of his system, to abolish the idea of self as a fiction, like the many preceding ones. Again he asks, from what impression can the idea of self be derived? And since he regarded a numerically identical and permanent self as something that continues "invari- ably the same" throughout the whole course of one's life— a grain of sand, as it were, or an atom of pure being, — an impression of the self must also be con- stant and invariable. But "there is no impression constant and invariable." Consequently, there is no impression of self as something that remains the same throughout one 's lif e.^ "What then is the self ? ' ' For my part, ' ' says Hume,^ "when I enter most intimately into what I call myself, I always stumble on some particular perception or other, of heat or cold, light or shade, love or hatred, pain or pleasure. I never catch myself at any time without a perception, and never can observe any thing but a perception. " " The mind is a kind of theatre," he continues, "where sev- eral perceptions successively make their appearance; pass, re-pass, glide away, and mingle in an infinite variety of postures and situations. There is properly no simplicity in it at one time, nor identity in differ- ent; whatever natural propension we may have to imagine that simplicity and identity. The compar- ison of the theatre must not mislead us. They are the successive perceptions only, that constitute the mind; nor have we the most distant notion of the place, where these scenes are represented, or of the materials, of which it is composed." » P. 533. « P. 534; cf. pp. 541, 542. SPIRITUAL SUBSTANCE, PEKSONAL IDENTITT. 239 After tlius professing to prove that tlie idea of self is invalid, Hmne undertakes to explain the genesis of the fiction. The explanation is exactly similar to that of the fiction of spiritual substance. Successive per- ceptions, by means of a quality of the imagination, are involuntarily regarded as constituting a continued existence. But the continued existence is interrupted in the course of every-day experience. Then, to solve the contradiction, the mind feigns the idea of self as something permanent and invariable, a fictitious ground of union for the ever-changing ideas of which the actual self is composed.^ In the appendix, the idea of self is not distinguished from that of spiritual substance; as already men- tioned,^ both are there treated together. And as no explicit reference is made in the Inquiry to either topic, further discussion of the subject is for the present unnecessary. We shall return to this ques- tion in a following section.' ^ § 43. The Idea of Personal Identity. — If the self is 'Inothing but a bundle_or collect ion of different pereeptidS,' wEicKjracMe^reaeEIo5^;^,wi^^^ ceivable rapidity, and a£e_ Jn^^ji^perpetu^^Jux j,nd "movement,"* it may be asked, How does the idea of . personal identity arise ? Personal identity, Hume ac- knowledges, in the Treatise has become a great ques- tion in philosophy, "especially of late years in Eng- land." He thinks it is to be explained in the same manner as the identity of plants, houses, ships, or rivers.^ Consequently, the identity which is com- monly ascribed to "the mind of man" is only "a 1 Pp. 535, 536; of. 11, pp. 74, 142. « P. 236. s Pp. 242-256. 4 Pp. 534. « Pp. 533, 539. 240 Hume's treatise and inquiby. fictitious one." "It is still true," he says,^ "that every distinct perception, ... is a distinct exist- ence, and is different, and distinguishable, and sep- arable from every other perception. . . . But, as, notwithstanding this distinction and separability we suppose the whole train of perceptions to be united by identity, a question naturally arises concerning this relation of identity ; whether it be something that really binds our several perceptions together, or only associates their ideas in the imagination." This mat- ter is easily decided by reference to the theory of cause and effect. "For from thence it evidently follows," continues Hume,^ "that identity is nothing really belonging to these different perceptions, and uniting them together ; but is merely a quality, which we attribute to them, because of the union of their ideas in the imagination, when we reflect upon them. ' ' These qualities of union are the relations of resem- . blance and causation.^ The idea of personal identity, like those of self and spiritual substance, is not dealt with in the Inquiry. Omitting an incidental reference in the Dialogues,* this subject received final treatment in the appendix. The account given here has been justly characterized' as one of those comprehensive reviews of the signifi- cance and the difficulties of Hume's empirical theory of cognition, which mark the rare acuteness of his intellect. In this reconsideration, Hume confesses* that, "upon a more strict review of the section con- cerning personal identity," he finds himself involved in "such a labyrinth," that he knows neither "how 1 P. 540. « Hid. a p. 541. * II, p. 406. 6 Adamson, Enoy. Brit,, art. Hume, p. 354. ' I, p. 558. SPIEITUAIi SITBSTANCE, PERSONAL IDENTITY. 241 to corject" his former opinions, nor "how to render them consistent." He then restates the arguments that induced him to deny "the strict and proper iden- tity and simplicity of a self or thinking being." These arguments are similar to those advanced previ- ously in the Treatise. After this restatement, how- ever, Hume brings forward an objection which did not appear in the earlier work. This objection is to the effect, that he is now unable satisfactorily to explain the principle of connection among perceptions. "Having thus loosened aU our particular percep- tions," he says/ "when I proceed to explain the principle of connection, which binds them together, and makes us attribute to them a real simplicity and identity; I am sensible, that my account is very de- fective, and that nothing but the seeming evidence of the precedent reasonings could have induced me to receive it." But "the seeming evidence of the pre- cedent reasonings" — that is, of the reasoning con- cerning the ideas of substance and necessary connec- tion—is so clear that he is compelled to accept it also. Hence, he concludes as follows:^ "In short there are two principles, which I cannot render consistent ; nor is it in my power to renounce either of them, viz., that all our distinct perceptions are distinct existences, and that the mind 'never perceives any real connection among distinct existences. Did our perceptions either inhere in something simple and individual, or did the mind perceive any real connection among them, there would be no difficulty in the case. For my part, I must plead the privilege of a skeptic, and confess, that 1 1, p. 559. = Ihid. 16 242 Hume's teeatise and mQumT. this difficulty is too hard for my understanding. I pretend not, however, to pronounce it absolutely in- superable. Others, perhaps, or myself, upon more mature reflections, may discover some hypothesis, that will reconcile these contradictions." Hume did not return to the question of personal identity. In the Inquiry, he stiU advocates the funda- mental principle, that "all our distinct perceptions are distinct existences,"^ and maintains that "the mind never perceives any real connection among distinct existences."^ There is no reason to suppose, there- fore, that he was ever able to reconcile the contradic- tion of which he speaks. And neither is there any ground for thinking that this standing contradiction modified to any appreciable extent, either the doctrine or the contents of the Inquiry. This is not the view, however, which is generally held by Hume's inter- preters. Some have professed to find in the confes- sion in the appendix a key to the solution of many difficulties regarding the meaning and position of the later work — an explanation of many omissions, and a ground for many apparent changes of doctrine. The question is an important one ; but unhappily, one that does not admit of an easy answer. In fact, Hume's doctrine of the self, in the Inquiry, is generally recog- nized as being the most perplexing problem in the whole work. Hence, we devote to the consideration of this subject an additional section. § 44. The Relation of the Treatise to the Inquiry on the Doctrine of Self and Personal Identity, — 1 Pp. 10, 27, 53, 61, 124, 125. 2 Pp. 27, 52, 61, 75. SPIRITUAL SUBSTANCE, PERSONAL IDENTITY. 243 Brede^ and Grimm^ are among the latest, as well as the ablest representatives of the theory that Hume, when he wrote the Inquiry, had become convinced of the existence of a real self and a real personal iden- tity ; and that this change of view had a marked effect upon the briefer exposition of his system. As there are no direct, and only a few indirect references to this question in the later work, the reasoning must be largely of the nature of probability. In support of Brede and Grimm's position* several arguments are adduced, which may be summarized in the following propositions:— (1) In the Treatise, Hume professed to explain the fiction, as well as to refute the doc- trines, of self and personal identity. (2) The expla- nation of these fictions is analogous to that of the fictitious idea of substance, and that of the assumption of external existence. (3) In the appendix, it is ac- knowledged, not only that the explanation given in the Treatise of the fiction of personal identity is "very defective," but also that Hume is now unable to give a derivation of this idea. (4) For these causes, the explanation of the fictitious ideas of substance, self, and personal identity— in fact, all explicit treatment of these subjects,— is omitted in the Inquiry. (5) For similar reasons, the assumption of the existence of an external world is attributed, in the later work, to an illusion of the senses ; and not, as in the Treatise, to a fiction of the imagination. (6) Since Hume, in 1 Der Untersohied d. Lehren E., pp. 46-49. ' Zur Gesch. d. Erhewntnisprdblems, pp. 575-577, 580-585. 3 It may be observed that Grimm's position is not quite so positive as is that of Brede. At times he seems to hold that Hnme has merely abandoned the doctrine of the self, as ex- poimded in the Treatise, without adopting the view of a real permanent self, as Brede claims. 244 humb's treatise and mQuroy. the appendix, acknowledged himself unable to explain the fiction of personal identity, and yet, in the In- quiry, made frequent use of the ideas of self and self- consciousness, he must, when he wrote the later work, have been convinced of the real existence of the self and personal identity, and thus have renounced the doctrine of the Treatise. (7) In confirmation of this conclusion are the facts: (a) Hume, in the Inquiry, speaks repeatedly of impressions and ideas being present to the mind, without ever saying that the mind ' is this sum of perceptions; (b) the Inquiry, he asserts, in the advertisement to the posthumous and authori- tative edition of his works, and not the Treatise, rep- resents his true position. (8) Finally, in the section on "A particular Providence and a future State," it is unaccountable why Hume did not bring forward his former doctrine of the self as an argument against belief in the iramortality of the soul, except on the ground that, in the meantime, he had abandoned that doctrine. Yet another argument, one hitherto overlooked, may be added to those of Brede and Grimm to complete the reasoning. Henry Home endeavored to persuade Hume not to publish the Inquiry; but in vain.^ A few years later, in 1751, Home published his Essays on the Principles of Morality and Natural BeUgion. One of the main objects of this work was to counter- act the influence of Hume's speculative writings.^ Before publishing, Home apparently sent the manu- script to his friend for perusal. The essay on "Per- sonal Identity" begins as follows:' "Had we no orig- 1 Tytler, Memoirs of H. B. of Karnes, I, p. 129. s Of. Hid., p. 131. 3 p. 231. SPIRITUAL SUBSTANCE, PEESONAL IDENTITY. 245 inal impressions but those of the external senses, according to the author of the treatise of human nature, we never could have any consciousness of self; because such consciousness cannot arise from any external sense. . . . Neither co^lld there be any idea of personal identity. For a man, cannot con- sider himself to be the same person, in different cir- cumstances, when he has no idea or consciousness of himself at all." Home then proceeds to show how, according to his theory, the ideas of self and personal identity arise from an internal impression.^ In 1746, Hume wrote to Home, regarding this essay:'' "I like exceedingly your method of explaining personal iden- tity, as being more satisfactory than any thing that had ever occurred to me." It might reasonably be supposed, therefore, that when Hume, in 1748, pub- lished the Inquiry, he had adopted the position of Home on the questions of self and personal identity— or, at least, had relinquished the doctrines of the Treatise; and it might also be thought that Home's treatment of personal identity, in connection with Hume's recognition in the appendix of the contradic- tion in his fundamental principles, had played an important part in determining the standpoint and contents of the later work. The argument, however, is not so formidable as it appears to be; moreover, there are some considerations on the other side of the question, which wUl, perhaps, give occasion to reverse the foregoing conclusion. Propositions (1), (2), and (3) are statements of fact that are admitted. Proposition (4) is admitted, 1 Pp. 232, 233. 2 Tytler, Memoirs of H. B. of Karnes, I, p. 124. 246 Hume's tkeatise and inquiey. in the main. Hume's recognition, in tlie appendix, that he could not explain the fiction of personal iden- tity is a valid reason— although probably not the only one, and perhaps not the chief one,— for the omission, in the Inquiry, of a treatment of the ideas of spiritual substance, self, and personal identity. Debate begins with proposition (5). Eegarding this part of the argument it may be remarked, that even if the truth of the conclusion be granted, the validity of the infer- ence is not established. For since Hume stiU believes that his method of explaining fictions, by means of the imagination, is valid, and satisfactory when applied to the idea of cause and effect — as he certainly does in the Inquiry,— there is no ground to suppose that he would hold the same method to be invalid or un- satisfactory when applied to the ideas of material substance and external existence; the three cases, on his principles, are exactly parallel. But it has al- ready been shown,^ that the conclusion is not true. For Hume, in the briefer work, looks upon "the vulgar hypothesis," or the assumption of the existence of an external world, as arising, not from the senses, but from "a natural instinct," and implies an explanation of it similar to that in the Treatise. Consequently, the argument in the fifth proposition is utterly with- out foundation. The position adopted in proposition (6) cannot be sustained. It is of course evident that Hume's confession, in the appendix, that he could not explain the fiction of personal identity is not a suffi- cient reason for assuming that his doctrine of the self was changed, when he wrote the Inquiry ; particularly, since it had remained unchanged when the confession iPp. 211, 212, above. SPIEITUAL SUBSTANCE, PEESONAL IDENTITY. 247 was made. When Hume acknowledged that his ac- count of personal identity was "a labyrinth" of in- accuracies and inconsistencies, he did not acknowledge that he had changed his doctrine regarding the self. "There is nothing," he says,^ "I would more willingly lay hold of, than an opportunity of confessing my errors." And what are his errors? "I have not yet been so fortunate," he replies, "as to discover any very considerable mistakes in the reasonings delivered in the preceding volumes, except on one article." That article is "the section concerning personal iden- tity." And with reference to it, he admits only "mistakes in the reasonings," not an error in the doctrine. In fact, he still maintains the same doc- trine of the self as he held in the Treatise. For he asserts:^ "When I turn my reflection on myself, I can never perceive this self without some one or more perceptions; nor can I ever perceive anything but the perceptions. It is the composition of these, there- fore, which forms the self." Consequently, it may reasonably be concluded that, since Hume's view of the self, when he wrote the appendix, was precisely the same as when he composed the Treatise, it had probably undergone no change when he prepared the Inquiry. That he should incidentally imply the ex- istence of a real self or personal identity, in the later work, and yet hold the idea of the same to be an illusion, is not any more remarkable than that he should occasionally imply the existence of a real power and necessary connection, and yet explain the ideas of these as actual fictions. Thus much with regard to the main argument. 1 1, p. 555. 2 I, p. 558. 248 Hume's treatise and inquiry. But there is yet some confirmatory evidence in favor of Brede and Grimm's position. In proposition (7) it is said that Hume often speaks of impressions and ideas being present to the mind, without once saying that the mind or self is a sum of perceptions. In the Inquiry, it is true, there are occasional refer- ences to the self; but they are so indefinite, that a satisfactory conclusion cannot be drawn from them either way.^ Some of these references favor one view, others the other. Thus Hume asserts •? "We attribute power to a vast ninnber of objects, ... to the Su- preme Being, ... to the mind in its command over its ideas and limbs, in common thinking and motion. ' ' Here it would seem that the mind is regarded as a real subject having command over its ideas and activi- ties. On the other hand, however, he states:' "The authority of the will over its own faculties and ideas is not a whit more comprehensible than the opera- tions of mind on body : So that, upon the whole, there appears not, throughout all nature, any one instance of connection, which is conceivable by us." He also declares* that "the mind has never any thing present to it but the perceptions," and further," that the rela- tions of resemblance, contiguity, and causation "are the only bonds, that unite our thoughts together, and beget that regular train of reflection or discourse, which, in a greater or less degree, takes place among all mankind." This is the same doctrine as that of the Treatise. True, Hume does not attempt to ex- plain how these relations, which are "the only bonds" that unite perceptions, produce a self, or an idea of J Of. pp. 9, 10, 54, 55, 56 n., 57, 60, 61, 76, 124. « P. 56 n. » P. 61. « P. 125. » P. 43; cf. p. 18. SPIRITUAL SUBSTANCE, PERSONAL IDENTITY. 249 personal identity. Therein lay his difficulty, as he acknowledged, in the appendix. And he seems simply to have claimed "the privilege of a skeptic," on con- fessing that the difficulty was "too hard" for his understanding.^ In this connection a casual reference in the posthu- mous work, the Dialogues concerning Natural Reli- gion, a reference which Hume's critics appear to have overlooked, is worthy of notice. In the discussion on the attributes of God Demea made the reply :^ "In reality Cleanthes, consider what it is you assert, when you represent the Deity as similar to a human mind and understanding. "What is the soul of man? A composition of various faculties, passions, sentiments, ideas ; united, indeed, into one self or person, hut still distinct from each other. . . . How is this com- patible with that perfect immutability and sim- plicity, which aU true theists ascribe to the Deity?" Of course, it may be objected that possibly Demea does not here speak for the author. But the weight of evidence is clearly on the other side, since Hume nowhere called in question the validity of Demea 's argument. It must be admitted, however, that the preceding reasoning is not quite convincing. From the incidental references in the Inquiry and Dialogues a probability at most, not a certain conclusion can be reached. And this probability inclines, perhaps, as much to the one side as to the other. For addi- tional evidence, therefore, we turn to the second part of Brede's argument in proposition (7), viz., Hume's claim that the Inquiry, rather than the Treatise, rep- resents his true position in his maturer years. 1 1, p, 559. ! II, p. 406. 250 Hume's treatise and inquiet. The advertisement to the posthumous and authori- tative edition— 1777— of the Essays and Treatises on Several Subjects was for a long time an enigma to the students of Hume's philosophy. It is only within recent years, through the liberality of the Earl of Rosebery, that the secret has been disclosed, by the publication of Letters of David Hume to William Strahan, edited by Gr. B. Hill. The advertisement in the Essays and Treatises begins as follows: "Most of the principles, and reasonings, contained in this vol- ume, were published in a work in three volumes, called A Treatise of Human Nature: a work which the author had projected before he left college, and which he wrote and published not long after." And it concludes: "Henceforth, the author desires, that the foUowing pieces may alone be regarded as containing his philosophical sentiments and principles." Many writers, naturally, have taken this declaration to mean a repudiation of the Treatise, and an avowal that the Inquiry alone is the true exponent of Hume's philosophical doctrines. Such a supposition, how- ever, is entirely erroneous. In 1740, Hume wrote to Hutcheson, respecting the Treatise, as follows:^ "I wait with some impatience for a second edition, prin- cipally on account of some alterations I intend to make in my performance." Hume had not repudiated the Treatise then. True, he intended to make some alter- ations in it. But these were only on account of "negligences" in "the reasoning," or in "the ex- pression, ' ' not on account of a change in opinions or principles.'' In 1742, in a letter to Home, he said •? 1 Burton, Ufe, I, p. 117. « Ibid., I, p. 337. « lUd., I, p. 143. SPIEITUAL SUBSTANCE, PERSONAL IDENTITY. 251 "The Essays [Moral and Political] are aU sold in London, . . . There is a demand for them; . . . They may proye like dung with marl, and bring for- ward the rest of my philosophy, which is of a more durable, though of a harder and more stubborn na- ture." Hume at this time judged rightly that the Treatise was "more durable" and harder than the Essays. He had not then repudiated it. In 1751, he wrote Elliot:^ "I believe the Philosophical Essays [the Inquiry] contain every thing of consequence re- lating to the understanding, which you would meet with in the Treatise ; and I give you my advice against reading the latter. By shortening and simplifying the questions, I really render them much more com- plete. Addo dum minuo. The philosophical prin- ciples are the same in both; but I was carried away by the heat of youth and invention to publish too precipitately. ... I have repented my haste a hundred and a hundred times." And in a letter, supposed by Burton to have been written late in life, but when, and to whom is not known, he states:^ ' ' That you may see I would no way scruple of owning my mistakes in argument, I shall acknowledge (what is infinitely more material) a very great mistake in conduct, viz., my publishing at all the 'Treatise of Human Nature, ' a book which pretended to innovate in all the sublimest paths of philosophy, and which I composed before I was five-and-twenty ; above all, the positive air which prevails in that book, and which may be imputed to the ardor of youth, so much displeases me, that I have not patience to review it. But what success the same doctrines, better illus- 1 Ibid., I, p. 337. * Hid., I, p. 98. 252 Hume's treatise and inquikt. trated and expressed, may meet with, adhuc sub juddce lis est." Hume has now given up the Treatise, ap- parently because of "the positive air" which pervades it ; but he still maintains its principles and doctrines. Soon, however, some important events occurred. In 1764 Reid's Inquiry appeared, and in 1770 Beat- tie's Essay on Truth. In both these books, Hume's system of philosophy is severely criticised, particu- larly the principles expounded in the Treatise, siace they are the ones more easily assailable. Hume in- dignantly resented the criticism of Beattie. Formerly he was displeased with "the positive air" of the earlier work; now he appears to be dissatisfied with "the reasoning." Under these circumstances he pre- pared the now famous advertisement, and sent it to Strahan, in 1775, for insertion in the coming edition. Hence, he complains: "Several writers, who have hon- ored the author's philosophy with answers, have taken care to direct all their batteries against the juvenile work, which the author never acknowledged, and have affected to triumph in any advantages, which, they imagined, they had obtained over it: a practice very contrary to all rules of candor and fair-dealing, and a strong instance of those polemical artifices, which a bigoted zeal thinks itself authorized to employ." At the same time, in his letter to Strahan, Hume ex- pressed the wish that he had -prefixed the advertise- ment to the previous edition— 1768,— and remarked :^ "It is a complete answer to Dr. Reid and to that bigoted silly fellow, Beattie." It is evident, there- fore, that when Hume desired the Inquiry to be re- garded by the public as alone containing "his philo- 1 Hill, Letters of D. E., pp. 289, 290; cf. p. 303. spieituaij substance, personal identity. 253 sophical sentiments and principles," he made this statement, not because he had given up the philosoph- ical sentiments and principles of the Treatise, hut because the position of the later work was less vul- nerable than that of the earlier,. Even in the adver- tisement he does not retract any of the doctrines of the Treatise; he merely hopes that "some negligences in his former reasoning and more in the expression" are corrected. He would undoubtedly stiU have ad- mitted, as he formerly asserted, that "the philosoph- ical principles are the same in both. ' ' But he would not perhaps defend this position ; for he was not only at all times averse to controversy, but exceedingly so in his later years. Thus the probability that Hume's view of the self was the same when he wrote the In- quiry as when he wrote the Treatise, a probability which resulted from the examination of explicit statements in the appendix and incidental references in the Inquiry and Dialogues, is now heightened to practical certainty, by the frank admissions of the author himself. Finally, Brede rejoins, in proposition (8), that if Hume still held the same view of the self as formerly, it is inexplicable why he did not make use of this doctrine in his argument, in the eleventh section of the later work, against belief in the immortality of the soul. The answer to this part of Brede 's reasoning is threefold:— (1) Such an argument Hume probably thought too subtle or abstruse to suit the character of the Inquiry. (2) The argument, in itself, is neither satisfactory nor decisive. As John Stuar,t MiU re- marked:^ "It is precisely as easy to conceive, that a 1 ExamitMtion of Sir WilUam Hamilton's Philosophy, p. 211. 254 hxjme's treatise and dstquiet. succession of feelings, a thread of consciousness, may- be prolonged to eternity, as that a spiritual substance for ever continues to exist: and any evidence which would prove the one would prove the other." This much is implied in the Treatise, in the section on "The Immateriality of the Soul." (3) As a matter of fact, Hume employed this argument in the dis- cussion on the attributes of God in his posthumous work, the Dialogues concerning Natural Religion. "What is the soul of man"? asked Demea,^ "A com- position of various faculties, passions, sentiments, ideas ; united, indeed, into one self or person, but still distinct from each other. . . . How is this com- patible with that perfect immutability and simplicity, which aU true theists ascribe to the Deity?" If additional proof were required in order to show that Hume's view of the self and personal identity was the same when he wrote the Inquiry as when he wrote the Treatise, attention might be called on the one hand, to the close correspondence which exists between the two works in so far as the subjects are treated in both, and on the other, to the fact that the omissions in the Inquiry are easily explained without attributing to Hume any important change of doc- trine. But further proof is not necessary. The In- quiry consists essentially of certain portions of the Treatise abbreviated and popularized. And Hume did not intend that it should take the place of the Treatise, any more than did Kant intend that the Prolegomena should take the place of the Critique of Pure Reason. On the contrary, when he composed the later work he hoped that it would help to bring i II, p. 406; of. p. 238, above. SPIRITUAL SUBSTANCE, PEESONAL IDENTITY. 255 forward the earlier, as containing his complete system of philosophy, into public notice. And this, in course of time, it did. There only remains now for examination Hume's admission when he wrote to Home: "I like exceed- ingly your method of explaining personal identity, as being more satisfactory than any thing that had ever occurj-ed to me." This statement may have been perfectly true. But even so, that does not necessarily imply that Home's method of explaining personal identity was acceptable to the author of the Treatise of Human Nature. Hume confessed, in the appendix, that his own explanation of personal identity was "a labyrinth" of inaccuracies and inconsistencies. He thought Home's explanation better, but he did not say how much better. On the other hand, when it is observed that Home's argument, in the essay on "Personal Identity" is only such a one as Hume professed to have completely refuted in the Treatise, and such as is palpably inconsistent with the funda- mental principles of the Inquiry; when it is remem- bered that Home was Hume's kinsman and patron who had written him a letter of introduction to Dr. Butler, and who had exerted all his influence, al- though in vain, to secure for the philosopher a uni- versity position; when it is noted that Hmne wrote his letter to his patron just before leaving England on a military expedition which was undertaken with a view to improving his financial position; when it is learned that Hume, after his unfortunate experi- ence with the Earl of Annandale— in which affair his "only crime" had been "too little dissimulation, and too strong an indignation at meeting with treach- 256 Hume's treatise and inquiet. ery and perfidiousness" where not expected,*— had become sufficiently a man of the world to be able to appreciate the value and importance of having friends in high places to advance his interests ; when, finally, it is borne in mind that Hume was always, not only exceedingly courteous, but also extremely generous, and even magnanimous, toward his philosophical critics and literary contemporaries— toward all except "the bigots,"— it will be quite evident that his con- cession to Home, concerning the latter 's explanation of personal identity, is to be regarded after the man- ner of a graceful compliment, rather than in the light of a candid acknowledgment. § 45. Conclusion.— The more important conclu- sions of the chapter may now be brought together. To Hume's statement: "I never catch myself at any time without a perception," Calderwood retorted that it ought to be enough "if he could catch himself with one." But Hume also asserted that he never could observe "any thing but the perception." In the V Treatise he affirmed:^ "The true idea of the human mind, is to consider it as a system of different per- ceptions or different existences, which are linked to- ' gether by the relation of cause and effect, and mu- tually produce, destroy, influence, and modify each .other." Of course, "produce, destroy, influence, and modify" are not to be understood according to the ordinary signification of the terms; they must be in- terpreted in the sense of Hume's meaning of power, or cause and effect. As the author stated elsewhere :* "No interual impression has an apparent energy, more 1 Murray, Letters of David Eume, p. 52. 8 P. 541. 3 P. 456. SPIRITUAL SUBSTANCE, PEESONAL IDENTITY. 267 than external objects have." It follows, therefore, that there is no idea of self after the manner ordin- arily explained.^ This idea is a fiction, arising through the influence upon the imagination of a series of resembling perceptions.^ Consequently, the actual identity of self is similar to that of houses, rivers, plants, or animals.* And the supposed idea of per- sonal identity is a fiction of the imagination, arising from the infiuence of the relations of resemblance and causation.* In the appendix," Hume admits that his explanation of personal identity is "very defective." He asserts, however, that it is not in his power to renounce either of the two principles: (1) "All our distinct percep- tions are distinct existences"; (2) "the mind never perceives any real connection among distinct exist- ences." He acknowledges that these two principles are contradictory, but pleads "the privilege of a skeptic," to evade further difficulty. Although there is no treatment of self or personal identity in the Inquiry, yet from statements in Hume's letters, from incidental references in his later works, and from the fact that he still maintained the two foresaid contradictory principles,® the conclusion is inevitable that his doctrine of the self was substan- tially the same when he wrote the Inquiry as when he wrote the Treatise. But since he was never able to reconcile the two contradictory principles, he would manifestly always be unable to give a satisfactory account of personal identity; consequently, this was 1 P. 533. 2 P. 535. ' p. 540. - P. 541. 6 1, pp. 558, 559. 5 Of. pp. 53, 145, 152, 153, 206, 210, above. 17 258 Hume's treatise and inquiet. one of the chief causes why he omitted entirely any further discussion of the subject. Other causes that might be assigned for this omission, no doubt, were the abstract nature of the subject, and the particular circumstances under which the later work was written. Nowhere, perhaps, is Hume's dependence on eigh- teenth century modes of thinking more clearly shown than in his conception and treatment of the self. Mathematical and physical ideas still held sway in the speculative thought of the age. Hume is the uni- versal analyzer, who tries to reduce everything to its constituent parts, hoping thereby to be able to explain the significance of the phenomenon under investiga- tion. But just as the biologist, when dissecting an organism, always loses the factor of life, so did Hume when analyzing perceptions, frequently lose the ele- ment of meaning. He seemed to possess it when starting out on his research. He has lost it when he reaches the end of his pursuit. And he then knows neither where to look for it, nor how to find it. Hence, he concludes, erroneously, that it was never present. It is extremely interesting to note that, in course of time, Hume came to recognize that his method was not perfectly satisfactory. Had he lived a century later, under the influence of the biological sciences, he would undoubtedly have arrived at a truer view of the self, as an organism which is something over and above the mere elements that enter into its con- stitution. CHAPTEB XII. MIRACLES, A PAETICULAB PEOVIDBNCE, AND A PUTUEE LIFE. § 46. Miracles. — Hume's doctrines of miracles, a particular Providence, and a future life are practical consequences of his philosophy of human nature, rather than constituent parts of it. Yet the author originally intended to treat these subjects, in part at least, in the earlier work. For certain reasons, how- ever, chiefly politic,^ he omitted a formal statement, and satisfied himself with incidental references. According to Hume's principles of unphilosophical probability, the degree of conviction or belief attend- ing a judgment or conclusion is much stronger when the decision is arrived at after examining a few propo- sitions, than when it is reached by means of a long chain of connected reasoning, even granting that each i argument, or link in the chain, in either case, has an| equal degree of probability.^ Consequently, the evi-1 dence for any historical fact will produce the less con- \ vietion, other things being equal, the farther back the fact is removed ia time. In Craig's* argument against "the Christian Religion," based upon the nature of historical evidence, each link in the chain of testimony is supposed to amount only to a probability. And Hume admits that, if this assumption be granted, 1 Burton, Ufe, I, p. 63. 2 I, pp. 440, 441. 3 TheologicB Christiance Principia Mathematica,. 259 260 Hume's treatise and inquibt. "there is no history or tradition, but wliat must in the end lose all its force and evidence."^ He does not, however, concede the validity of Craig's argument, for two reasons: (1) Historical testimony in some cases amounts to a proof; (2) when the links in the evidence are all of a similar nature, the strength of the conviction does not diminish in proportion to the length of the chaia. It was undoubtedly in connection with this subject, that Hume intended to set forth his own reasoning on miracles. Writing to Campbell, in 1762, he gives an interesting account of the origin of his argument. "I was walking in the cloisters of the Jesuits' College of La Fleche," he says,'' "and engaged in a conversation with a Jesuit of some parts and learning, who was relating to me, and urging some nonsensical miracle performed lately in their convent, when I was tempted to dispute against him; and as my head was fuU of the topics of my Treatise of Human Nature, which I was at that time composing, this argument immedi- ately occurred to me, and I thought it very much graveled my companion; but at last he observed to me, that it was impossible for that argument to have any solidity, because it operated equally against the Gospel as the Catholic miracles; — which observation I thought proper to admit as a sufficient answer. I believe you wiU allow, that the freedom at least of this reasoning makes it somewhat extraordinary to have been the produce of a convent of Jesuits, though perhaps you may think the sophistry of it savors plainly of the place of its birth." Prudential consid- erations induced the author to omit his "reasoning 1 1, p. 442. 2 Burton, Ufe, I, p. 57. MIEACIiES, PROVIDENCE, AND FUTUEE LIFE. 261 concerning miracles" in the Treatise, being afraid it would give "too much, offence," as "the world" was then "disposed."^ In the Inquiry, after referring to Tillotson's argu- ment against "the real presence," the author flatters himself that he has discovered "an argument" against miracles "of a like nature, which, if just, wiU, with the wise and learned, be an everlasting check to aU kinds of superstitious delusion, and consequently, will be useful as long as the world endur,es."^ For so long, he presumes, "wiU the accounts of miracles and prodigies be found in all history, sacred and profane. " It should be noted, at the outset, that Hume's argu- ment against miracles is, strictly speaking, not a criti- cism of their objective possibility, but an examination of their subjective credibility. It is a disquisition , on the laws of evidence or principles of human testi- 1 mony. In order, to discuss the subject intelligently, a definition is necessary; two are given.' Huxley* finds fault with the form of these definitions, but he neglects to notice that, later in the discussion, the author added an explanation of them. This explana- tion, it is true, appeared at first as a foot-note, and not until the edition of 1770 was it incorporated with the text. Hume regards a miracle as "a violation of the laws of nature" ;" that is, a violation of "the usual course of nature," as that is recognized by scientists.^ In this sense, the definition is not open to Huxley's criticism. An opinion prevails generally that Hume claims to = Burton, Life, I, p. 63. 2 P. 89. ' P. 93, and n. * Eume, pp. 128-130. 6 P. 93. " P. 105. 262 Hume's teeatise and inquiry. demonstrate tliat no amount of evidence is sufficient to prove a miracle. Such opinion, of course, is a mis- conception, albeit a misconception whicli in large measure is excusable, on account of the author's mode of treatment. Hume acknowledges, not only "that there may possibly be miracles," but that there may be miracles which ' ' admit of proof from human testi- mony."^ What he denies is, that miracles which are made "the foundation of a [popular] system of re- j ligion" are capable of proof. ^ His argument falls \ into two .divisions. The first is, in substance, as fol- lows :°^ miracle is a violation of the established laws of nature; the laws of nature rest upon "a firm and unalterable experience"; a uniform experience amounts to "a full proof"; consequently there is a fuU proof against "the existence of any miracle." It may be assumed, however, that in some instances human testimony in support of a miracle amounts to "an entire proof" also. "In that case," says Hume,* "there is' proof against proof, of which the strongest must prevail, but still with a diminution of its force, in proportion to that of its antagonist. . . . The plain consequence is, ... ' That no testi- mony is sufficient to establish a miracle, unless the testimony be of such a kind, that its falsehood would be more miraculous, than the fact, which it endeavors to establish : And even in that case ther,e is a mutual destruction of arguments, and the superior only gives us an assurance suitable to that degree of force, which remains, after deducting the inferior.' " Thus far, Hume's argument is essentially sound. True, it is not ' Ibid., of. II, p. 249. 2 P. 105. » P. 93. ■" Pp. 93, 94. MERACLES, PEOVIDENCB, AND FUTURE LIFE. 263 above criticism with reference to form, since it con- tains an ' ' ambiguous middle. ' ' For the ' ' full proof, ' ' on which the laws of nature rest, is not the same kiud of ' ' full proof ' ' which is capable of being established upon human testimony; that is, "full proof," as in- deed the author implies, does not always mean exactly the same thing. But this objection is evaded, con- sciously or unconsciously, in the statement of the con- clusion. Hence the reasoning, thus far, may be re- garded as perfectly valid. The' above argument is only the first part of Hume's reasoning. In the second part, he claims to show that he has been "a great deal too liberal" in his conces- sion with respect to the validity of human testimony, and that "there never was a miraculous event" estab- lished on such evidence as was equivalent to a full proof.^ After an examination of the nature of evi- dence, he thinks, upon the whole, that "no testimony for any kind of miracle [which is to serve as a founda- tion for a popular system of religion] has ever amounted to a probability, much less to a proof." And he concludes •? "We may establish it as a maxim, that no human testimony can have such force as to prove a miracle, and make it a just foundation for any [popular] system of religion." This part of the argument is open to criticism. When treating of miracles, two kinds should be distinguished, external, and internal.' The former are events in the physical world, and as such are open to the observation of the people present. The latter are experiences in the life of the individual, and hence appear directly only to his own consciousness. Proof of the former de- 1 P. 94. « P. 105. 3 Cf. IV, pp. 89, 108. 264 Hume's treatise and inquiey. pends on external evidence, proof of the latter on internal. Hume's reasoning applies only to external miracles, and to external testimony. Whether or not such testimony has proved the existence of miracles which might serve as "the foundation of a [popular] system of religion" will not be discussed here, since the question lies beyond the scope of this inquiry. It is sufficient to remark, that the second part of Hume's argument is sophistical, and that his final conclusion is vitiated by the "ambiguous middle" already ad- verted to. The "full proof" arising from human testimony may, at times, be complete and certain ; while the "full proof" on which the laws of nature rest is, at most, only a probability, the conclusion from an imperfect induction. Hume stiU admits, as every thinker must admit, the possibility of miracles.^ But his conclusion is wider than his premises when he asserts, that no human testimony can prove a miracle, "so as to be the foundation of a [popular] system of religion." "Whether or not there have been such miracles in the past is wholly a question of evi- dence, a question on which there may be honest dif- ferences of opinion. And whether or not there will be such miracles in the future cannot be determined by any reasoning whatever. Near the close of the discussion, Hume made the following singular confession:^ "I am the better pleased with the method of reasoning here delivered, as I think it may serve to confound those dangerous friends or disguised enemies of the Christian Religion, who have undertaken to defend it by the principles of human reason." The meaning of this avowal is ' P. 105. ^ 2 P. 107. MIRACLES, PEOVIDEISrCE, AND FUTURE LIFE. 265 still a matter of uncertainty. A writer in the Dublin University Magazine affirms:^ "The only thing [in the Essay on Miracles] likely to offend [Dr. Butler] or any right judging person, is the paltry subterfuge with which the essay closes, in which [the author] affects to patronize Christianity. . . . The single excuse for this style was the state of the laws in most countries in Europe, and certainly in Scotland. ' ' On the other hand, Grimm^ thinks that Hume does not attack the Christian miracles. And Calderwood' is of the opinion that Hume, in his reference to the Christian miracles, is perfectly sincere. The last view is the one most nearly correct; yet it is correct only in part. The distinction drawn above between ex- ternal, and internal miracles is of service here. It is agaiast the former class only that Hume's argument is directed ; to the latter, it has no application. Hume rejects external miracles; he believes in internal miracles. And many of his readers— some less, some more spiritually minded than he— have felt the force, and have been convinced of the essential truth of his conclusion:* "The Christia/n Beligion not only was at first attended with miracles, but even at this day can- not be believed by any reasonable person without one. Mere reason is insufScient to convince us of its ver-\ acity : And whoever is moved by Faith to assent to it, ' is conscious of a continued miracle in his own person, which subverts all the principles of his understand- ing, and gives him a determination to believe what is most contrary to custom and experience." 1 Vol. XXVII, p. 362 n.; ef. Orr, David Hume, pp. 198, 216. 2 Zvr Gesch. d. Erkermtnisproblems, p. 513. > Ewne, Preface, and p. 91. * P. 108; cf. 11, p. 249; IV, p. 135. 266 Hume's treatise and inqtjiet. § 47. A Particular Providence.— It is often said that Hume's theory of causation overturns the foun- dation stone of philosophical theism. Undoubtedly, any validity that the cosmological argument might be supposed to have ought to disappear for the author of the Treatise of Human Nature, since he asserts that it is easy "to conceive any object to be non-existent this moment, and existent the next, without conjoin- ing to it the distinct idea of a cause or productive principle. ' '^ And yet, it is by no means certain that Hume rejected the common argument for the exist- ence of a first cause, for in the Dialogues he made Philo declare:" "Nothing exists without a cause; and the original cause of this universe (whatever it be) we call God ; and piously ascribe to him every species of perfection. Whoever scruples this fundamental truth, deserves every punishment, which can be in- flicted among philosophers, to wit, the greatest ridi- cule, contempt and disapprobation." But inasmuch as the cosmological argument, irrespective of any criticism of the idea of cause and effect, has ceased to satisfy the philosophical mind, Hume's theory of causation need not necessarily affect his position on the question regarding the existence of a particular Providence. The few casual remarks on this subject, in the Treatise and appendix, may be compared with the fuller statement of the Inquiry. In the earlier work Hume asserts :° "If every idea be derived from an impression, the idea of a deity proceeds from the same origin ; and if no impression, either of sensation or reflection, implies any force or efficacy, it is equally impossible to discover or even ' I, p. 381. 2 II, p. 391. » P. 454. MmACLBS, PROVIDENCE, AND PUTUKB LIFE. 267 imagine any such active principle in the deity. ' ' But although he affirms that it is impossible to discover or imagine any active principle in "the deity," he declares that it is "absurd and impious" to exclude this principle from "the supreme beiag."^ These references obviously imply the existence of God. It would seen, however, as if the Divine Existence, not being the object of any impression, must remain es- sentially unknowable. In the appendix Hume is more explicit. He de- clares:^ "The order of the universe proves an om- nipotent mind ; that is, a mind whose wiU is constantly attended with the obedience of every creature and being. Nothing more is requisite to give a founda- tion to all the articles of religion, nor is it necessary we should form a distinct idea of the force and energy of the supreme Being. ' ' The vague theism foreshad- owed in this passage harmonizes with that portrayed in a letter to Muir, a few years later, and very prob- ably is similar to his view at the time he wrote the Treatise. To Muir— about 1744— he wrote:' "Iti must be acknowledged, that nature has given us a\ strong passion of admiration for whatever is excel- ^ lent, and of love and gratitude for whatever is ben- evolent and beneficial; and that the Deity possesses these attributes in the highest perfection: and yet I assert, he is not the natural object of any passion or affection. He is no object either of the senses or imagination, and very little of the understanding, without which it is impossible to excite any affection." When one turns from this passage to the Inquiry, the story of the ass, as Huxley remarks,* that took to 1 P. 455. ' I, p. 456 n. » Burton, Life, I, p. 162. * Hume, p. 144. 268 HUME'S TREATISE AND nSTQUIRy. the water, wlieii it was laden with salt, suggests itself. Hume's theism "dissolves away in the dialectic river," until little is left but "the verbal sack" in which it was contained. In section xi — entitled "A Particular Providence and a Future State," or as designated in the first edition, "The Practical Consequences of Natural Religion,"— Hume is represented by Epi- curus, who makes a harangue to the Athenian people on the subjects of God and immortality. The reason- ing concerning a particular Providence is a rejoinder to the argument in Butler's Analogy. The deists had claimed that certain doctrines of revealed religion were inconsistent with the attributes of the Supreme Being. Butler showed that the natural religion of deism was open to a similar objection, and drew the conclusion that since this criticism was not valid against natural religion, neither was it effective against revealed religion ; that just as there are blem- ishes in nature so one might expect to find defects in a divine revelation. On the other hand, Hume as- serts that the objection holds in both cases. His argument is precisely analogous to that which he had formerly made to the Jesuit priest on the subject of miracles. The speaker admits the existence of God— a divine existence he had "never questioned"^ — but asserts that the attributes of God can be inferred only from the course or order of nature. The ontological and cosmological arguments, naturally, have no place ; but the teleological argument appeals strongly to Hume's mind,'' as it did later to Kant's and to John Stuart MiU's. "Allowing, therefore," says Epicurus,® "the 1 P. 112. 2 Ibid. J cf. 11, pp. 392, 443; TV, p. 309. > P. 113. MIBACLBS, PEOVIDENCE, AND FUTURE LIFE. 269 gods to be the authors of the existence or order of the universe ; it follows, that they possess that precise de- gree of power, intelligence, and benevolence, which appears in their worfccaanship. ' ' But there appear to be defects in the workmanship, evils and disorders in the world.^ This, to every apologist, is the appalling crux of the problem. Although Epicurus asserts the existence of God, he denies a particular Providence and "supreme governor of the world, who guides the course of events, and punishes the vicious with in- famy and disappointment, and rewards the virtuous with honor and success, in all their undertakings."^ At the same time, he does not neglect to assert: "I deny not the course itself of events, which lies open to every one's inquiry and examination. I acknowl- edge, that, in the present order of things, virtue is attended with more peace of mind than vice, and meets with a more favorable reception from the world. I am sensible, that, according to the past experience of mankind, friendship is the chief joy of human life, and moderation the only sour.ce of tranquility and happiness." It is said, in reply, that from the ob- servation of "a half -finished building," one could infer from the effect, although incomplete, that it was "a work of-design. "^ But Epicurus rejoins that the world is a unique effect, and consequently, that only so far as it shows wisdom and goodness, just so far can one ascribe wisdom and goodness to the cause. "A body of ten ounces" raised in a scale may serve as a proof that the counter balancing weight exceeds ten ounces, but not that it exceeds "a hundred." Similarly, the print of a foot on the sand can only ip. 114. «P. 115. 3 P. 117. 270 Hume's treatise and inquiet. prove, when considered by itself, "that there was some figure adapted to it, by which it was produced." True, the print of a human foot indicates that it was probably accompanied by another foot, which also left its impress, although effaced by time or accident. But in this process of reasoning one ascends from the effect to the cause, and then descends from the cause to the effect with the help of other experience. Such mode of procedure is not permissible when dealing with a unique effect like the universe.^ It but aids the assent of reason with "the wings of imagination." Finally, the writer suggests the query, as an objection to the argument of Epicurus, whether it be possible for a cause to be known only by its own particular effect? whether a cause can be of so singular and particular a nature as to have no parallel and no similarity with any other cause or object?" To this inquiry Epicurus makes no rely. It is evident, there- fore, that the last objection is meant to be the au- thor's; and it is probable that, ia accordance with his theory of causation, he would answer his final question in the negative. Hume seems to hold a form of theism resembling that adopted later by John Stuart MiU. He affirms the existence of God. He doubts only the nature or attributes of God.* He asserts that God is intelligent, but does not say that he is all-wise. It is on the moral side of the question, however, that Hume, like many others, finds the most perplexing difficulty.* And here it seems as if reason is for ever fated to put her finger on her lips, and in awe and reverence whisper, "silence." Other minds clearer and pro- 1 Pp. 118, 119. ! P. 121. > Cf. II, p. 391. * Cf. II, p. 443. MIRACLES, PROVIDENCE, AND FUTURE LIFE. 271 founder even than Hume's, and other spirits loftier and nobler far than his have met with scarcely any better success than did he, in dealing with this mo- mentous problem. In the Natural History of Religion, and in the Dialogues concerning Natural Religion, Hume treated at considerable length the more important religious questions. The Dialogues is one of the great master- pieces in religious criticism. The author, of whom . it has been said with much show of plausibility that he had "neither any twist of vice nor any bias for doing good,"— was well qualified for such a work. No doubt he was fully conscious of his success, and for that reason took special care that it should not be suppressed after his death. Besides, a peculiar per- sonal feeliag must have become bound up with a work which needed a quarter of a century for its composi- tion, and which was then retained for another quarter of a century, partly for further improvement, partly because the author desired "to live quietly, and keep remote from all clamor."^ But although the Dia- logues presents a vivid picture of Hume's theological diflSculties and intellectual strivings, it gives little in- sight into the real nature of his religious convictions. There is no general agreement as to which speaker represents the writer; not even is there unanimity regarding the position of the several interlocutors,^ — much less regarding the position of the author.' 1 Of. Hill, Letters of D. B., p. 330. 2 Of. Adamson, Ency. Brit., art. Hume; Burton, Life, I, p. 329. 3 Of. Burton, Life, I, p. 329; Knight, Hume, pp. 209, 213; MeCosh, Agnosticism of H. and Huxley, pp. 13, 51; Stephen, History of English Thought, I, p. 342; Jodl, Lehen u. Phil. 272 Hume's teeatisb and inquiey. / Several writers think that Cleanthes represents Hume.^ Many, however, assert that Philo does;= some think Cleanthes and Philo ;' and others all three.* The last view, notwithstanding Hume's disclaimer,^ is undoubtedly the more correct one. For while the author does not fuUy assent to aU that is said by any of the speakers, each of them, iu turn, voices his thought and sentiments. It is Plume's letters and conversation which convey the most valuable information regarding the develop- ment and character of his religious opinions. To Elliot, in 1751, he wrote:* "You would perceive by the sample I have given you, that I make Cleanthes the hero of the dialogue : whatever, you can think of, to strengthen that side of the argument, will be most acceptable to me. Any propensity you imagine I have to the other side, crept in upon me against- my will; and it is not long ago that I burned an old manuscript book, written before I was twenty, which contained, page after page, the gradual progress of my thoughts on that head. It began with an anxious search after arguments, to confirm the common opin- ion ; doubts stole in, dissipated, . . . returned again ; D. H., pp. 191, 192, 194 J Paulsen, Dialoge uber natiirliche ReUgion und Selbstmord, p. 16; Windelband, Gesoh. d. n. PMl., p. 333 J Lechler, Gesch. d. englisohen Deismus, p. 436. 1 Burton, Life, I, p. 329; Ritchie, Life of Hume, p. 43; Stewart, Worlcs, I, p. 434 n. ' Huxley, Hume, p. 151 ; Priestley, Letters to a Philosophical VnbeUever, p. 127; Orr, Dwoid Bume, p. 201. » Windelband, History of Philosophy, p. 494. 'Knight, Hume, p. 209; Porter, Science and Sentiment, p. 298. 6 Ritchie, Life of H., p. 43. 6 Burton, Life, I, pp. 331, 333. MIRACLES, PEOVIDBNCE, AND FUTURE LIFE. 273 and it was a perpetual struggle of a restless imagina- tion against inclination, perhaps against reason. . . . I could wisli Cleanthes ' argument could be so analyzed, as to be rendered quite formal and regular." To Balfour, in 1753, he wrote :^ "I must only complain of you a little for ascribing to me the sentiments, which I have put in the mouth of the skeptic in the Dialogue. I have surely endeavored to refute the skeptic, with all the force of which I am master, and my refutation must be allowed sincere, because drawn from the capital principles of my system." To Stra- han, in 1776, he wrote :^ "I there [in the Dialogues] introduce a skeptic, who is indeed refuted, and at last gives up the argument, nay confesses that he was only amusing himself by all his cavils; yet before he is silenced, he advances several topics, which will give umbrage, and wiU be deemed very bold and free, as well as much out of the common road." And to John Stewart he wrote:' "I am not such a skeptic as you may perhaps imagine." When dining one eve- ning with the French Encyclopaedists, he asserted that he had never seen an atheist.* To Mrs. Mallet he denied being a deist.° To Ferguson, on a beauti- ful star-lit night, he exclaimed:" "Oh, Adam, can any one contemplate the wonders of that firmament, and not believe that there is a God!" And when weeping over his mother's death, he is said to have replied to Boyle:'' "Though I threw out my specula- - RiteUe, Life of B., p. 43. ' Hill, Letters of D. H., p. 330. 3 Burton, Life, II, p. 454. « Qua/rterVy Review, Vol. GIL, p. 310. 5 Hardy, Memoirs of Charlemont, I, p. 235. 8 Burton, Life, II, p. 451. ' Oarlyle, Autobiography, p. 274. 18 274 Hume's treatise and inquikt. tions to entertain and employ the learned and meta- physical world, yet in other things I do not think so differently from the rest of manlrind as you may imagine." From these citations, it is clear that Hume's doubts on religious questions appeared at a very early age, that he strove earnestly to overcome them, and that he never succeeded. It is probable, therefore, that his position regarding the existence of a particular Providence was the same when he wrote the Treatise as when he wrote the Inquiry. And it is evident that the vacillation and indeflniteness in his writings on religious subjects are due neither to indecision, nor to caprice, but to many-sidedness. Although he made Cleanthes the hero of the Dialogues, he would have assumed the role of Philo himself, had Elliot been with him to take the part of Cleanthes.^ He en- deavored to refute the skeptic; but at the same time he advanced several topics which he knew would give "umbrage." Although he declared that the skeptic was refuted and put to silence, yet so strongly did he present the case for Philo, that many of his readers have thought the skeptic had the better of the argu- ment. Thus Huxley asserts:^ "If Hume reaUy knew of any valid reply to Philo 's argument in the follow- ing passages of the Dialogues [II. pp. 407, 408], he has dealt unfairly by the reader in concealing it." While Hume could exclaim with the Psahnist: "The heavens declare the glory of God ; and the firmament > Burton, Life, I, p. 332. 'Hume, p. 148; of. Adamson, Snoy. Brit., art. Hume; Orr, David Hume, p. 201 ; McCosli, History of Boottish Philosophy, p: 145; Stephen, History of English Thought, 1, p. 342, Win- delband, History of Philosophy, p. 494. MIEACLES, PROVIDENCE, AND FUTURE LIFE. 275 showeth. his handiwori"; he could equally confess with the agnostic: "The whole is a riddle, an enigma, an inexplicable mystery."^ And it is not at aU sur- prising if the avowed skeptic expressed himself with true reverence and sincerity in the conclusion of the Dialogues:'' "The most natural sentiment, which a well-disposed mind wiU feel on this occasion, is a longing desire and expectation, that heaven would be; pleased to dissipate, at least alleviate this profound' ignorance, by affording some particular revelation to mankind, and making discoveries of the nature, attri- ', butes, and operations of the divine object of our faith. " ', §48. A Future Life. — There remains now but one topic for discussion, the question of a future life. Near the close of the Treatise, there is a section on the "Immateriality of the Soul," a doctrine which Hume declares to be a true atheism, almost the same as the "hideous hypothesis" which had made Spinoza "universally infamous."* Hume with his system of impressions and ideas, some of which are extended and some unextended, laid claim to refute both the materialistic and the idealistic theories of the soul. If the soul be extended, he asks, how can it have un- : IV, p. 363. s II, p. 467; of. KnigM, Hume, p. 220; Burton, Life, 1, pp. 281, 282; Calderwood, Hume, p. 91; Quarterly Review, Vol. OIL, p. 311; Falckenberg, History of Modem Philosophy, p. 230; Windelband, Qesoh. d. n. Phil., 1, p. 331. — 'Wor the con- trary view, cf. Piinjer, Hist, of the Christian Phil, of Religion, p. 377 J Maurice, Moral and Metaphysical Phil., II, p. 575; Duilin University Magasme, Vol. XXVII, p. 362 n.; Lange, Hist, of Materialism, II, p. 162; Jodl, Leben u. Phil. D. H., p. 86; Orr, Damd Hume, pp. 196, 198. 3 P. 524. ♦- 276 Hume's teeatisb and inquiry. extended perceptions? and if it be unextended, how can it have extended perceptions? Consequently, "the question concerning the substance of the soul is absolutely unintelligible."^ He professes, however, that his arguments are not "any ways dangerous to religion," and offers the following "apology" to re- move the apprehensions of those who might think they were:^ "There is no foundation for any conclu- sion a priori, either concerning the operations or dura- tion of any object, of which it is possible for the human mind to form a conception. Any object may be imagined to become entirely inactive, or to be an- nihilated ia a moment ; and it is an evident principle, that whatever we can imagine, is possible. Now this is no more true of matter, than of spirit; of an ex- tended and compounded substance, than of a simple and unextended. In both cases the metaphysical arguments for the immortality of the soul are equally inconclusive; and in both cases the moral arguments and those derived from the analogy of nature are equally strong and convincing." The value of this apology, on account of the peculiar circumstances under which it was made, cannot be exactly determined.* Hume's critics generally assert that the philosophy of the Treatise of Human Nature strikes at the very root of the doctrine of immortality.* According to that system, there is no valid idea of 1 P. 532. s iii4, » Of. Burton, Life, I, pp. 279, 280. « Of. 1, p. 292; Knight, Ewme, p. 219; McCosh, Agnosticism, of H. and Buaoley, p. 51; Lange, Hist, of Materialism, II, p. 162; P.unjer, Hist, of the Ohristiam, Phil, of Bel., pp. 377, 378; Brede, Der UntersoJded d. Lehren Humes, p. 48; Tennemann, Mamial of the Hist, of PHI., p. 373. MIEACIiES, PROVIDENCE, AND FUTURE LIFE. 277 personal identity, and the self is nothing but a btmdle or collection of perceptions, which succeed one an- other without any real connection. Thus, to cite one of Hume's memorable passages:^ "When my percep- tions are removed for any time, as by sound sleep ; so long am I insensible of myself, and may truly be said not to exist. And were aU my perceptions removed by death, and could I neither, think, nor feel, nor see, nor love, nor hate after the dissolution of my body, I should be entirely annihilated, nor do I conceive what is farther requisite to make me a perfect nonentity, ' ' Of course, Hume does not say that perceptions are removed by death. Any one who pleases may assume that they still continue after the dissolution of the body. He merely contends that if the soul ceases to perceive, it ceases to be. And he further contends that his metaphysical reasoning is not prejudicial to the interests of religion, for the moral arguments and those derived from the analogy of nature are strong and convincing in proof of the immortality either of a material, or of an immaterial soul. In the appendix there is only a passing reference to the subject of a future life, and it is of a similar import to the remarks in the Treatise. "The anni- hilation," says Hume,^ "which some people suppose to follow upon death, and which entirely destroys this self, is nothing but an extinction of aU particular perceptions; love and hatred, pain and pleasure, thought and sensation. These therefore must be the same with self; since the one cannot survive the other." True, in another passage he declares:* "The order of the universe proves an omnipotent mind; 1 I, p. 534. 2 I, p. 559. » I, p. 456 n. 278 Hume's treatise akd inquirt. that is, a mind whose will is constantly attended with the obedience of every creature and being. Nothing more is requisite to give a foundation to all the articles of religion." Here Hume admits that the doctrine of immortality has a valid foundation, if it be one of "the articles of religion." But it is obvious from some passages in other of his writings, that he does not so regard this doctrine.^ The conclusion, there- fore, seems to be that while the author neither affirms nor denies a personal belief in immortality, he implies that a proof of it from moral arguments, and from those derived from the analogy of nature is possible. In the Inquiry, Htmie was not restrained by a de- sire to obtain for his philosophy, either the good opinion of Dr. Butler, or the applause of the learned world. Accordingly, he discussed the question of a future life with his usual freedom. In the opening remarks of his address, Epicurus, the author's pro- locutor, observes:^ "We shall not here dispute con- cerning the origin and government of worlds. We shall only inquire how far such questions concern the public interest. And if I can persuade you, that they are entirely indifferent to the peace of society and security of government, I hope that you will presently send us back to our schools, there to ex- amine, at leisure, the question, the most sublime, but, at the same time, the most speculative of all philos- ophy. " Then, after dealing briefly with the problem of a particular Providence, the speaker asks:* "But what must a philosopher think of those vain reasoners, who, instead of regarding the present scene of things as the whole object of their contemplation, so far 1 Cf. IV, p. 111. 2 p. 111. s p. 116. MIEACLES, PROVIDENCE, AND. FUTURE UFE. 279 reverse the wliole course of nature, as to render this life merely a passage to something farther; a porch, which leads to a greater, and vastly different build- ing; a prologue, which serves only to introduce the piece, and give it more grace and propriety? From their ovra conceit and imagiaation surely. For if they derived it f r,om the present phenomena, it would never point to any thing faj-ther, but must be exactly adjusted to them." And since the arguments on this subject are to be drawn from experience, or from the phenomena of nature,^ Hume denies the validity of any pretended proof for the existence of a future life. It may here, of course, be objected that undue weight is attached to the remarks of Epicurus. It may be said that Epicurus is a historical character, and that the opinions to which he gives utterance are his own, rather than Hume's. The position appears to be well taken. The opinions expressed are, no doubt, those of Epicurus. The question now to be considered is, are they also those of Hume ? Naturally, one turns to the essay on "The Im- mortality of the Soul" for additional information regarding the author's belief. In this essay, printed in 1755 but withdrawn before publication, Hume does not rest satisfied with attemptiag to show that the existence of a future life is incapable of proof. He now carries the war into the enemy's country by ad- vancing several arguments against the doctrine of immortality. He not only recedes from his position affirmed in the Treatise, that the moral arguments and those derived from the analogy of nature are strong and convincing, but he undertakes to show that ' P. 117. 280 Hume's treatise and inquiet. the arguments drawn from metaphysics, from morals, and from physical science are all futile. Certain phases of the moral argument, in particular, he sub- jects to severe criticism. "By what rule are punish- ments and rewards distributed?" asks Hume,^ "What is the Divine standard of merit and demerit?" And he replies: "Punishment, without any proper end or purpose, is inconsistent with our ideas of goodness and justice ; and no end can be served by it after the whole scene is closed. . . , "Were one to go round the world with an intention of giving a good supper to the righteous and a sound drubbing to the wicked, he would frequently be em- barrassed in his choice, and would find, that the meritp and demerits of most men and women scarcely amount toth^j value of either. . , . "The chief source of moral ideas is the reflectior on the interests of human society. Ought these in ' terests, so short, so frivolous, to be guarded by punish ments, eternal and infinite? The damnation of on< man is an infinitely greater evil in the universe, thai the subversion of a thousand millions of kingdoms.' It may, perhaps, be replied that Hume's strictures however effective they may be against certain im plications of the doctrine of immortality, do not in validate the counter argument of Butler. Bishoj Butler pointed out that rewards and punishment take place in this world, conduct being always fol lowed by its natural consequences. And since a sys tern of rewards and punishments, in the present life is compatible with the nature of the Infinite WDl, i may equally be so in a future life. The pleasure 1 IV, pp. 402, 403. MIRACLES, PROVIDENCE, AND FUTUBE LIFE. 281 and pains experienced here may continue throughout eternity, iacreasitig, ditmnishing, or changing as they do now. Such reasoning, however, affords but slight consolation. For Hume's pitiless rejoinder would come, even in the words of the inspired writer: "The righteous perisheth, and no man layeth it to heart," or "Wherefore doth the way of the wicked prosper? Wherefore are they happy that deal treacherously"? It should also he observed that Hume's argument against the existence of a future life does not conclu- sively determine the character of his own belief. For with his peculiar double-sidedness, he immediately gave back with one hand what he took away with the other. Although he maintained that the doctrine of a future life could not be proved by reason, he opened the discussion with the significant remark:* "In real- ity, it is the gospel, and the gospel alone, that has brought life and immortality to light" ; and he con- cluded the essay with the equally impressive state- ment: "Nothing could set in a fuller light the infinite obligations which mankind have to Divine revelation ; since we find, that no other medium could ascertain this great and important truth." Before proceeding farther with the discussion, it may be advantageous to take a brief review of Hume's position in his different writings. In the Treatise,'' he asserts that the moral arguments for immortality, and those derived from the analogy of nature are "strong and convincing." In the Inquiry/ he declares that the existence of a future life cannot be proved— indeed he seems to come very near denying such exists ence altogether.* And in the essay on "The Immor- 1 IV, p. 399. 2 P. 333. s P. 116. « Pp. 110, HI. 282 ' Hume's teeatise and inquiet, tality of the Soul," he not only contends that the existence of a future life cElnnot be proved by reason, but also advances many arguments against its actu- ality ; while at the same time, he acknowledges that it is a "great and important truth," discovered by the light of "Divine revelation." The vacillating and conciliatory attitude of the Treatise must be attrib- uted mainly to Hume's "cowardice" — to use his own term,— along with his desire to obtain for his system of philosophy the favorable opinion of Dr. Butler.^ And the unrestrained mode of expression in the In- quiry is largely explained by his eagerness to produce a murmur among "the zealots."* But whether the extreme, position of the later work is due, in some measur.e, to a firmer conviction, as the author grew older, not only that the immortality of the soul is incapable of proof, but also that there is really no future life for the individual, is a question which cannot easily be determined. Nor does the suppressed essay, with its Janus-face, appear, at first sight, to furnish any satisfactory solution of the difficulty. Following the method taught by Hume, in his reasoning on cause and effect, we find a clue, in sub- stituting for our assigned question, whether, the opin- ions of Epicurus were also those of the author? a related question, viz., was the author sincere when he declared, in the ^ssay, that the doctrine of immortality is a great and important truth, made known by Divine revelation ? If Hume was not sincere in this expres- sion, he was probably not sincere in his remarks in the Treatise, and his real view is most nearly expressed in the Inquiry; that is, Epicurus speaks for the au- • Burton, Life, I, p. 64. 2 My Oum lAfe. MIRACLES, PBOVIDENOE, AND PUTUEE LIFE. 283 thor, as well as for himself. But on the other hand, if Hume was sincere in the essay, it may fairly be inferred that he was sincere in the Treatise also, and that the account in the Inquiry differs from those in the Treatise and essay, not in being inconsistent— as some critics maintain— but in being indefinite and ambiguous. In that case, Epicurus must be regarded as speaking only for himself, not for the author. In support of each of these alternatives a few arguments may be adduced. With an examination of the evi- dence on both sides of the question, our assigned task will be concluded. I. In favor of the former supposition, viz., that Hume was not quite sincere in his reference to the doctrine of immortality as a "great and important truth" of revelation, may be stated three considera- tions : 1. Hume openly professed that he did not believe in the doctrine of a future life. To Hardy he said :^ , "Why troth, man, it is so pretty and so comfortable / a theory, that I wish I could be convinced of its truth, / but I canna help doubting." Now if a person pub- licly rejects one of the fundamental tenets of a pop- ular or dominant religion, it will generally be found that -his skepticism extends even farther, than his pro- fession. For considerations of self-interest and feel- ings of sympathy naturally attach him to the same religious views as those of his friends and neighbors. There are exceptions, of course, to the general rule. And Hume, it must be admitted, may have come under the exception. Many circumstances lend support to such an opinion. He had no close family ties; he 1 iife of the Ewl of Charlemont, I, p. 233. 284 Hume's treatise and inquiby. had no high or generous enthusiasms; he cherished a strong feeling of iadependence, possessed an indom- itable spirit of self-reliance, and took pride in being thought a skeptic. Hence the argument based on his outward profession is not conclusive. 2. From the accounts of Hume 's death it seems that, in his last days, he had no expectation that after his decease he would live again. McCosh^ narrates a story —though he questions the truth of it— told by a person who professed to have attended the philosopher on his death-bed, and according to which, the patient experi- enced, at times, the most "unutterable gloom." But the statement is unworthy of the slightest credence. Hume's correspondence with Strahau, during the lat- ter part of his illness is exceedingly interesting and significant. On June 12, 1776, writing with regard to the publication of the Dialogues, he said:" "It is an idle thing in us to be concerned about any thing that shall happen after our death; yet this is natural to aU men, and I often regretted that a piece, for which I had a particular partiality, should run any hazard by being suppressed after my decease." He stUl continued making corrections for the coming edi- tion of his works. On July 27, he sent three pages for his history, remarking: "You wiU wonder, that, in my present situation I employ myself with such trifles, and you may compare me to the modern Greeks, who, while Constantinople was besieged by the Turks and they themselves were threatened with total de- struction, occupied themselves entirely in disputes con- cerning the procession of the holy Ghost. Such is the 1 History of Scottish Philosophy, p. 133. ! Hill, Letters of D. H., p. 337. MIRACLES, PROVIDENCE, AND FUTURE LIFE. 285 effect of long habit. ' ' Strahan replied on August 1 :^ "This wiU be a very correct edition, and I will take care it shall be printed accurately and neatly; . . . By the by, does not this almost universal solicitude to live after we close our eyes to this present scene, mean something? I hope, I almost believe it does." On July 30, Hume sent a further correction. On Au- gust 12, he sent another, and bade farewell to his pub- lisher. ' ' This, Dear Sir, ' ' he said, ' ' is the last correc- tion I shall probably trouble you with : for Dr. Black has promised me, that all shall be over with me in a very little time : This promise he makes by his power of prediction, not that of prescription. And indeed I consider it as good news : For of late, within these few weeks, my infirmities have so multiplied, that life has become rather a burthen to me. Adieu, then, my good and old Friend. David Hume." Yet an- other correction, the last, was added in a post-script. Strahan replied on August 19, and asked the follow- ing peculiar question:^ "Only permit me to ask you a question or two, to which I am prompted, you will believe me, not from a foolish or fruitless curiosity, but from an earnest desire to learn the sentiments of a man, who has spent a long life in philosophical in- quiries, and who, upon the extreme verge of it, seems, even in that awful and critical period, to possess all the powers of his mind in their full vigor, and in unabated tranquility. "I am more particularly led to give you this trouble, from a passage in one of your late letters, wherein you say. It is an idle thing in us to be concerned about any thing that shall happen after our death; yet this, > Hill, Letters of D. E., p. 340. " Burton, Life, U, p. 512. 286 Hume's treatise and inquiet. you added, is natural to all men. Now I would eagerly ask, if it is natural to all men, to be interested ia futurity, does not this strongly indicate that our existence will be protracted after this life ? "Do you now believe, or suspect, that all the powers and faculties of your own mind, which you have cul- tivated with so much care and success, will cease and be extinguished with your vital breath? * ' Our soul, or immortal part of us, some say, is able, when on the brink of dissolution, to take a glimpse of futurity ; and for that reason I earuestly wish to have your last thoughts on this important subject." Hume received the letter a day or two before his death, but did not answer it. Soon after, his brother replied:^ "Though he possessed his faculties, and understand- ing and cool head, tp the last, he was scarce in condi- tion to answer [your letter] , nor the question you put to him : but so far as I can judge, his sentiments with regard to futurity were the same, as when he was in perfect health and was never more at ease in his mind, at any period of his life." Thus with the public protestations of the philosopher while in health, fully accords his conduct on the approach of death. 3. Furthermore, it may be added that Hume was not one of those who think that absolute sincerity on all occasions is expedient or desirable. In the begin- ning of his practical life— when residiag with the Marquis of Annandale, — after experiencing some painful and disadvantageous consequences of his act- ing honestly and disinterestedly, he wrote:" "My only crime has been too little dissimulation, and too great 1 Hill, Letters of D. B., p. 359. 2 Murray, Letters of D. H., and extracts, etc., pp. 52, 53. MIRACLES, PROVIDENCE, AND FUTURE LIFE. 287 an indignation at meeting with treachery and per- fidiousness, where I did not expect it. . . . My con- nection with the family will be very short, and give me occasion aU my life to reflect on the mischiefs arising from too great trust and confidence." After taking part in a military campaign, mingling in state diplomacy, and acquiring the art of making one's way in the world, he wrote :^ "It is putting too great a respect on the vulgar, and on their superstitions, to pique one's self on sincerity with regard to them," and added that, without a little "innocent dissimula- tion, or rather simulation," it is impossible "to pass through the world." This argument, it is true, wiU work either way. While it implies that Hume was not actuated always by motives of the strictest integ- rity or singleness of purpose, it does not indicate whether his evident insincerity, in the present in- stance, was manifested in his writings, or in his con- versation ; whether in his professed acceptance, in the essay, of the doctrine of immortality as a truth of revelation, or in his pretended rejection of it, in his daily life, as a speculative dogma without influence on conduct. Tet when this argument is taken in con- nection with the preceding ones, the inference seems inevitable, that Hume was not perfectly sincere ia his reference to immortality as an important truth, dis- covered by the light of Divine revelation. II. Before giving final assent, however, to the con- clusion just arrived at, it may be deemed requisite to examine also the arguments in favor of the latter alternative, viz., that Hume was sincere in his refer- ence, in the essay, to the doctrine of immortality as a 1 Burton, Ufe, II, pp. 187, 188. 288 Hume's treatise and inquiet. divinely revealed truth. Two reflections suggest themselves : 1. There is nothing inherently inconsistent in the belief that the existence of a future life cannot be proved by reason, but is a revelation from Heaven, a true and precious message from the heart of Nature to her children. On the contrary, many eminent thinkers before Hume's time held this view, as indeed many have held it since. 2. In support of the theoretical position just indi- cated, there are some practical considerations: Hume encouraged his servants to attend a place of worship ; he went to church regularly himself, and took part in the counsels of the established church of Scotland.^ The historian doubtless realized that the doctrine of immortality had exercised a marvellous influence on the progress and civilization of the western world. The philosopher must at times have recognized that belief in a future state is the source of unspeakable comfort and ennobling encouragement to multitudes of sorrowing and weary travellers oppressed by life's troubled pflgrimage. And although the psychologist clearly perceived that this belief is not always pro- ductive of pleasure, nor of the most beneficial re- sults, yet he understood weU that the threatened pun- ishments of the nether-world are, in general, not realized very keenly. In the Treatise,'' the author naively observed that "in matters of religion men take a pleasure in being terrified," and that "no preachers are so popular, as those who excite the most 1 McCosh, History, of Scottish Philosophy, p. 155; Burton, Life, 11, p. 453. 2 P. 414. MIEACLBS, PROVIDENCE, AND FUTURE LIFE. 289 dismal and gloomy passions." With sucli thoughts as the foregoing flashing, at least fitfully, across a receptive and many-sided consciousness, the subtle, sympathetic mind of Hume may have been moved with reverence to exclaim:^ "Nothing could set in a fuller light the infinite obligations which mankind have to Divine revelation ; since we find, that no other medium could ascertain this great and important truth." Notwithstanding the justness of the foregoing re- flections, there are serious objections to the validity of the conclusion— if that conclusion attribute to Hume anything more than a passing though pious sentiment, when he eloquently referred to the doctrine of immortality as a truth of Divine revelation. There is a passage in the Inquiry of more than usual signifi- cance, which calls first for consideration. Epicurus insists that he does not undermine "the foundations of society," nor loosen "the ties of morality," when, in his "philosophical disquisitions," he denies the existence of a future state. And the Athenian people reply: Even should it be conceded that the doctrine of immortality is wholly a speculative principle, and consequently should have no influence on practical life, yet in reality it has a very decided sway over the character and conduct of mankind.^ Hume is here giving an account of the actual facts of human ex- perience, as he had observed them in everyday life. In the eighteenth century, philosophers and scientists had advocated perfect liberty of thought for the sake of individual well-being and the advancement of truth; while princes and priests had fostered a belief 1 IV, p. 406. » IV, pp. 110, 111. 19 290 humb's treatise and inquirt. in the immortality of the soul for the welfare of the' state and the prosperity of the church. Hume, as a member of the former class, acknowledged that the common man, or the man of emotional temperament may he powerfully influenced in. his conduct by the doctrine of future rewards and punishments, and that the highly speculative mind, or the man of abstract thought is but little affected in his daily work by the common beliefs of a hereafter. Moreover, Hume also knew that although the politicians, as well as the philosophers, had much reason on their side, yet neither party had all. For man, whether ignorant or learned, is a social being, and not a logical machine. As a social being, he is a creature of habit. And in many instances, when character is once formed, philo- sophical theories and religious beliefs— though they may have played a large part in molding the character —have exceedingly little influence on conduct. It is then of infinitely more moment what kind of person one is, than what sort of beliefs one has. For Hume, as for Epicurus or the philosophic sage, the doctrine of immortality was of extremely little consequence. The natural impulses of sympathy and benevolence, of self-love, and self-respect were the great motive forces that dominated his life, that made him in the true sense of the word a good citizen, and in the ordinary acceptation of the term an honorable man. Furthermore, we incline to the view that, apart from revelation, the strongest ground for belief in a future life is the desire of the fond parent to meet again a departed child, or of the disconsolate spouse or lover for a glad reunion in the spirit-land, where there wiU be no more separations and no more sorrow. MIEACLES, PROVIDENCE, AND FUTURE LIFE. 291 Hume belonged to neither of these two classes of people. He once congratulated himself on the fact that, as a number of small fevers are said to prevent a great one, so in like manner, since he entertained a sentiment of regard for, all the members of the fair sex, he was not in danger of becoming enamoured of any one. With open heart and with characteristic freedom, the philosopher dissipated his affection on humanity; while with masterly hand and national genius, the man of affairs centred his care on self. Hume early knew that he had drawn a lucky lot from the lap of Lachesis, and the vast resources of his marvellous mind he diligently employed to make his path in life prosperous and pleasant. After a few slight mishaps in fitting out his craft, he sailed suc- cessfully on the bright waters of an ever-flowing tide, rarely rising high on mountain crests, nor ever sinking low in abysmal hoUows. Favored with sunny sky and enlivening breeze he kept far from shoals, and free from breakers. Finally, when putting in to port, he remarked, in the Autobiography, "that a man of sixty-five, by dying," cut off only "a few years of infirmities." He had had a good day, and was then "detached from life." Although he had seen his own good ship glide over the waves of time in a silvery track, he had observed many others, no less worthy than his, buf- feted by the storms of adversity, or broken on the rocks of misfortune, or perchance engulfed in the ocean of eternity, ere the hopes, the aspirations, and the enthusiasms of the mariner h*ad been fairly kindled. And he may very reasonably have had no desire to venture on another voyage upon an unknown 292 Hume's treatise and inquiry. sea, when, judging of the future from the past, in accordance with the principles of his own philosophy, he had no rational ground to expect that the new scene of things would be much better than the old. CHAPTER XIII. CONCLUSION. § 49. Summary.— The relations which obtain, either in the way. of agreement or of difference, between the Treatise and Inquiry, may now be summarized. There is not any subject whatever on which there is perfect agreement. In the Inquiry, there are omissions, or additions, or there is a modification of doctrine, or a difference in method, in the treatment of every topic. Leaving out of consideration those slight variations that are of no significance, it may be said that the position of both works is identical on the following points : intrinsic or primary aim, cause of perceptions, association of ideas, abstract or general ideas, cause and effect, philosophical probability, liberty and neces- sity, and the reason of animals. The position of both works is practically the same on the following points : subject-matter, method, nature and classification of perceptions, mathematics, belief, material substance, and external existence. Agreement is implied, al- though not formally expressed, on the following points : the ideas of space and time, intuitive knowl- edge, the distinction between natural and philosoph- ical relations, between impressions of sensation and reflection, and betwen the ideas of memory and im- agination. On the subjects of unphUosophical prob- ability, self, and spiritual substance, it may be in- ferred, from the general tenor of the treatment of related questions, from incidental references in other writings, and from statements in letters, that Hume's 293 294 humk's treatise and inquikt. view was the same when he wrote the Inquiry as when he composed the Treatise. From his remarks on per- sonal identity, in the appendix, it would seem that his view on that question underwent a change. The extent of this change, however, it is impossible to ascertain. The chief differences in the Inquiry are omissions and additions. The omissions are of two kinds: (1) Complete, for example, the treatment of philosophical relations, intuitive knowledge, unphilosophical prob- ability, and the ideas of spiritual substance, self, and personal identity. (2) Partial, for instance, the treatment of impressions of reflection, ideas of mem- ory, general or abstract ideas, ideas of space and time, mathematics, philosophical probability, general rules, material substance, and external existence. The addi- tions are: (1) Some practical application of Hume's theoretical principles, for example, the treatment of miracles, a particular Providence, and a future state ; (2) the transference of the discussion on liberty and necessity from Book II of the Treatise of Human Nature to the Inquiry; (3) the fuller development of the argument on the idea of necessary connectionj * (4) a more accurate account of belief; and (5) a fuller or more explicit recognition of the function of instinct. Besides these differences, it may be noted that Hume's extrinsic or secondary aims are not the same as formerly, and that the division of "the ob- jects of human reason" into relations of ideas and matters of fact is substituted for the classification of complex ideas and the sub-division of philosophical relations. The reasons for the omissions are: (1) The author's CONCLUSION. 295 desire to present the more important and interesting parts of his philosophy briefly, clearly, and in a pop- ular manner. (2) The inherent di£6.'culties in some of the subjects themselves. (3) The discovery that the principle of connection among ideas, in the at- tempted explanation of the fiction of personal iden- tity, was "very defective." The reasons for the addi- tions are: (1) Hume's desire to call attention to the significance of the philosophical principles of the Treatise; (2) his desire for fame and notoriety; (3) his comparative indifference to the reception which the Inquiry would receive from certain classes of people, the favorable opinion of whom he had wished to obtain for the Treatise; (4) his desire to answer objections that seem to have been provoked by the mode of treatment in the earlier work; and (5) his clearer psychological insight regarding the nature of belief and the function of instinct, when he wrote the Inquiry. § 50. Hume's System of Philosophy. — It may yet be asked, "What is Hume's philosophical position? Is his system to be classified as idealism, realism, ma- terialism, positivism, or skepticism ? Statements may be discovered in his writings in favor of every one of these philosophical theories. The most obvious ex- planation of this apparent inconsistency is the many- sidedness and liberal-mindedness of the man. Knight, when speaking of the difficulty of determining Hume's place in the Dialogues concerning Natural Religion, discerningly remarked i'^ "It must not be forgotten, . . . that he had a certain amount of sympathy with aU the characters; and that each of them (Demea » Hwne, p. 209. 296 Hume's treatise and inquiet. included) alternately mirrored his own ever-changiag mood. This kaleidoscopic character of Hume's mind has not been sufficiently recognized. " Only an inter- pretation like this can render intelligible the subtle turns of thought, the rapid changes in point of view, and the unexpectedly inconsistent expressions that are frequently met with in his philosopical writings. The true position of our author will best be indicated by reference to the more important subjects which he treats, viz., epistemology, metaphysics, and philosophy of religion. I. Epistemology. On the question of epistemology, Hume may be said to be a positivist, at least after his own fashion. His subject-matter is impressions and ideas; his method, observation and experiment. The chief problems of epistemology are: (1) The origin of knowledge; and (2) the nature or validity of knowledge. On the first question, Hume is a thor- oughgoing empiricist. In both the Treatise and In- quiry, he regards all knowledge as having its origin in impressions of sensation. On the second question, viz., the validity of knowledge, our, author is not so positive. There is no doubt, of course, that the doc- trine of both, works is essentially idealistic and phe- nomenalistic. But in systems of phenomenalism, this part of the theory of knowledge is a variable factor. In order to represent accurately Hume's view on the question of the validity of knowledge, it is necessary to take account of his threefold treatment of certainty, or the three stages in his exposition, which we have called the epistemological, the logical, and the psycho- logical. 1. The Epistemological Exposition. According to CONCLUSION. 297 the account in tlie Treatise, all knowledge or reason- ing consists of relations,— relations among impressions and ideas. Of relations there are two classes, those that always remain the same so long as the impressions and ideas upon which they are based remain the same, and those that may change without any change in the impressions or ideas. The former class fall within- the sphere of intuition and demonstration. They are objects of knowledge, as distinguished from probabil- ity. They are practically exact and certain, and con- stitute "the foundation of science." Among the demonstrative relations, however, there is one sort— the science of geometry— which form an exception to the general rule, in that they are not exact, because they are based on the images of sense and imagination, that is, on a standard which is not precisely true. The other class of relations constitute what is called probable knowledge, or more strictly speaking, proofs and probabilities. AU reasoning concerning proofs is based upon the relation of cause and effect, and consequently, cannot be more certain than the founda- tion on which it rests. Proofs and probabilities differ only in degree, the former being founded on the more permanent principles-of the imagination, the latter on the less permanent. 2. The Logical Exposition. In Part IV, Hume subjects "the faculty, which judges," as well as the content about which the judgment is made to a relent- less criticism. The result of this criticism is twofold: (1) Knowledge, properly so called, "degenerates into probability"; (2) all probabilities, that is, knowledge, proofs, and probability, are resolved into "a total ex- tinction of belief and evidence." But this extreme 298 Hume's treatise and inquirt. skepticism does not represent the true position of the author. It represents the position which would log- ically result, according to the principles of the philos- ophy of human nature, if belief were, as many sup- pose, an act of the understanding. 3. The Psychological Exposition. Belief, Hume holds, is not an act of the understanding, but a feel- ing, an instinct, or a product of the imagination. Thus nature, by means of certain qualities of the imagination, prevents utter skepticism, and deter-' mines one with a sort of necessity to view certain ob-l jects in a particular manner, and to believe just as well as to breathe or feel. Hence, there exists a con- flict between the principles of the imagination, and the principles of the understanding or reason— al- though the latter are but "the more established prop- erties" of the former. And not only does this con- flict exist between the imagination and reason, but each of these classes of principles, if followed exclu- sively, leads to contradiction or absurdity. Eeason, when it acts alone, entirely subverts itself; and the imagination alone runs into all sorts of absurdities and error. Thus there is "no choice left but betwixt a false reason and none at all. ' ' And Hume admits that he knows not what then "ought to be done." He only knows what generally is done, viz., that "this difficulty is seldom or never thought of." In other words, the result of logical reflection is utter skep- ticism. But nature demands action, and action is the radical cure for skepticism. Hume 's theory of knowl- edge, therefore, is theoretically and logically, complete^ skepticism; but practically and actually, it is a sys- tem of idealistic positivism. And the peculiar char- CONCLUSION. 299 acteristic of this positivism is that while it cannot be rationally justified, yet it has sufficient authority and validity to serve all the purposes of life.^ In Books II and III of the Treatise of Human Na- ture, the two classes of knowledge which are called relations of ideas and matters of fact were gradually substituted for the two classes of philosophical rela- tions, which were dealt with in Book I. Consequently, in the Inquiry all objects of human reason fall into these two classes, relations of ideas, and matters of fact. Relations of ideas possess intuitive or demon- strative certainty, and thus constitute knowledge strictly so called. Reasoning concerning matters of fact is based upon the relation of cause and effect, as in the Treatise, and thus possesses only probable cer- tainty. But this probable certainty is agaia of two kinds, proofs, and probabilities in a narrower sense. AU relations of ideas are sometimes spoken of as possessing exactness and certainty. Geometry, in- deed, as ordinarily treated, contaiQS many contradic- tions and absurdities ; but Hume thinks that these may be removed by adopting his theory of general ideas. The manner in which this is to be done, however, he does not attempt to show ; nor is it to be neglected that he regards the fundamental ideas of geometry as being derived from the senses, and as being based on the general appearances of objects to the senses or imag- ination. Relations of ideas and matters of fact are subjected, in section xii, to a criticism somewhat similar to that made in Part IV of the Treatise. Hume professes to Wf. Butler, Analogy, p. 3. — "But to us, probability is the very guide of life." 300 HUME'S TREATISE AND INQUIET. point out that there are contradictions and absurdities in the relations of ideas, as these subjects are com- monly dealt with by philosophers, and states that reason is so dazzled and confounded by these difficul- ties that "she scarcely can pronounce with certainty and assurance concerning any one object. " And with regard to matters of fact, he maintains that there is a contradiction between the senses, instinct, or imagina- tion, on the one hand, and the reason or understand- ing, on the other. Hume thinks that most of the con- tradictions among relations of ideas may be removed by adopting his' view of general ideas. And he affirms that the great subverter of Pyrrhonism or excessive skepticism is action, employment, "and the occupa- tions of common life. ' ' He asserts that his skeptical objections might be displayed at greater length, "if any durable good or benefit to society could ever be expected to result from them. ' ' For a similar reason he suppressed the essays on "Suicide" and the "Im- mortality of the Soul." It does not seem that there is any essential differ- ence of standpoint, or of doctrine in the Inquiry and Treatise, on the two general questions of epistemology. Differences of treatment, of course, are prominent; but most of these are easily explained. With regard to the topic of geometry, it is true, an apparent dif- ference of doctrine may be observed. And yet, even on this question, the position of the later work is practically the same as that of the earlier. The sub- ject is not dealt with in detail. This was done in the dissertation on "The Metaphysical Principles of Geometry," which Hume sent to Millar for publica- tion in 1755, but withdrew on account of some defect CONCLUSION. 301 either "in the argument oi in its perspicuity." Con- sequently, the significance of the alterations in the form of statement, in the Inquiry, cannot be exactly determiued. Also in the exposition of belief, although the doctrine remains in principle the same, there is a more explicit recognition of the emotional elements, and of the different types of belief, than in the earlier work. Finally, the faculty of imagination receives less consideration than formerly. In the Treatise, Hume maintained that the memory, senses, and under- standing are "all of them founded on the imagina- tion." Yet he asserted that this principle is "incon- stant, ' ' and that men of bright fancies are like those angels, "whom the scripture represents as covering their eyes with their wings." Like the sage of Chel- sea, the philosopher of NineweUs clearly saw that by the imagination people everywhere are most easily ' ' governed and beguiled. ' ' In the Inquiry, the sphere of action for this faculty, on account of omissions, is considerably restricted, and a portion of its authority is shared in common with instinct. One might sup- pose, therefore, that this modification in treatment ensued naturally, as Hume grew older. The change is an interesting fact, but whether it has any signifi- cance, aside from that, seems to be beyond the power of determination. Our author, like other great thinkers, lived before his time. He was a man of the nineteenth century, rather than of the eighteenth. In the departments of political science, economics, philosophy, religion, and especially psychology, he was a pioneer. As a modern psychologist, he placed himself squarely on the broad ground of experience. As a keen observer, he recog- 302 humb's treatise and inqxjiet. nized the facts. And as an impartial investigator, lie accepted them all. The problem of knowledge, how- ever, was too difficult for. satisfactory treatment by means of the mechanism furnished him by the eigh- teenth century. In the course of the development of his doctrine, perplexities, absurdities, and contradic- tions arose. He pointed these out freely. And he acknowledged that he could not solve them. But he did not, on that account, proclaim that consciousness is fallacious, or that like Satan, it is "a liar from the beginning." Hamilton's celebrated dictum, "falsus in uno, falsus in omnibus," had rightly no place in his philosophy. He merely recognized that conscious- ness, indeed like most people in the world, does not teU the truth, on all occasions. His successors, how- ever, instead of giving their attention to the improve- ment of the science of man, with the help of better apparatus, seized the materials he left and used them as infernal machines, with which they sought to de- stroy the foundation he endeavored to construct. It is said that the politicians of some countries, when com- pelled by the pressure of public opinion to carry out any important reform, try aU the possible wrong ways of doing the thing, before adopting the right one. In like manner, the philosophers seemed long intent upon trying all other possible theories, before going back to Hume. II. Metaphysics. Metaphysics has been employed in several different senses, for example, the science of being, the science of first principles, a systematic exposition of a priori judgments, etc., or as Hume sometimes used the term, any abstruse or profound reasonings. As now generally understood, metaphys- CONCLUSION. 303 ics investigates two problems, one ontological, the other cosmological, viz., "What is the ultimate nature of reality? and what is the form of reality, or the nature of the connection which exists between the totality of things? On both these questions Hume, in the Treatise, is not merely a skeptic, but also a dog- matist. The possibility of a metaphysics is excluded on his theory of knowledge. AU knowledge arises from experience. Experience means ultimately sense experience, and one-sided at that. Consequently, the ideas of necessary connection, material substance, spiritual substance, self, and personal identity, in short, aU primary metaphysical ideas are fictitious and invalid. And in every case, a professed explana- tion is given of how the fiction arises, through the influence of imagination and custom. This latter ele- ment, the derivation of fictitious metaphysical ideas, is Hume's most important, as well as his most dis- tinctive positive contribution to philosophy. In the Inquiry, Hume's position on the question of metaphysics is logically, although not actually the same as that in the Treatise. The subject-matter and method are similar. All knowledge arises from ex- perience. Experience is equivalent to sense experi- ence. And the author draws the conclusion, in a gen- eral way, that a metaphysics is impossible. He does not, however, treat the several problems of meta- physics after the same manner as in the earlier work. He takes up one question, that of causal connection, deals with it as he did in the Treatise, and arrives at the same conclusion with reference to it. The idea of necessary causal connection is a fiction, arising through the influence of imagination and custom. 304 humb's teeatise and inquiry. Now the question arises, Wliat is Hume's position, in the Inquiry, on the other metaphysical questions, viz., material substance, spiritual substance, self, and personal identity? Three different answers are pos- sible. In the first place, it may be said that, in the appendix, he acknowledged that the principle of con- nection among ideas, when employed to explain per- sonal identity, was very defective, and that he knew neither how to correct that account nor how to render it consistent. Hence, it may be thought that this con- fession is the key to the Inquiry, that it explaiiis why a treatment of personal identity, self, and substance is omitted in the later work. The author's view, on these questions, underwent a fundamental change; and therefore, the position of the Inquiry is radically different from that of the Treatise.* Secondly, it may be said that since the fundamental principles are the same in both works, Hume thought it was not neces- sary to show a second time the application of these principles to all metaphysical questions in detail. He shows, in an exhaustive manner, the application of his principles to one of these questions, viz., necessary connection, with a result identical to that in the Treatise. He implies that they hold, in a similar way, when applied to the others. Consequently, the omis- sions in the later work are merely for the sake of brevity and popular treatment, and the position of both works is exactly the same." Thirdly, there is an intermediate view, one that seems to be nearer the 1 Of. Grimm, Zw Qesoh. d. ErhmntnisproUems, pp. 580, 583; Brede, Der Unterschied d. Lehren H., pp. 47, 49. ' Cf. Green, " Introdvtction to Hume"; Orr, David Hume, p. 45. CONCLUSION. 305 truth than either of the preceding. The fundamental principles, as Hume himself said, are identical in both works ; therefore, the same conclusions as in the Trea- tise logically follow in the Inquiry. But the author recognized a difficulty in the appendix, and this diffi- culty is a standing one. It applies, however, only to the ideas of spiritual substance, self, and personal identity. The principle of customary conjunction among ideas is as adequate to explain the fictitious idea of material substance, and the hypothesis of ex- ternal existence as to explain the fiction of necessary connection. Hence, on these questions, Hume's view was exactly the same when he wrote the Inquiry as when he wrote the Treatise. Over and above the many references, in the later work, in favor of this conclusion, convincing proof is easily accessible in his letters and essays. Writing to Home in 1746, he said:^ "As to the idea of substance, I must own, that as it has no access to the mind by any of our senses or feelings, it has always appeared to me to be nothing but an imaginary centre of union amongst the different and variable qualities that are to be found in every piece of matter." Hume's principles of association, however, are not adequate to explain the fictitious ideas of self and personal Identity. Hence, on these subjects, the standpoint of the two works is obviously somewhat different. Here is a real cause for the omission, in the Inquiry, of a treatment of these problems. But it is not a sufficient reason for asserting that our author's view, on any of these ques- tions, is changed. It is highly probable, nay it is practically certain that his doctrines of spiritual sub- 1 Tytler, Memoir of Eervry Home of Karnes, II, p. 124. 20 306 bxtmb's treatise and inquiry. stance, self, and personal identity were the same when he wrote the Inquiry as when he wrote the Treatise. Consequently, while the position of both works, on the chief problems of metaphysics, is not formally iden- tical, yet essentially it is. The rejection of meta- physics, although not so thorough, is just as real in the Inquiry as in the Treatise. III. Philosophy of Religion. Although questions in philosophy of religion are treated in the Inquiry, in the Natural History of Religion, in the Dialogues, and in the essay on "The Immortality of the Soul," only three problems are discussed in the Inquiry, or referred to in the Treatise, viz., a particular Provi- dence, miracles, and a future life. A word on each. 1. The Existence of God. Hume was never an atheist, and he objected to being called a deist. He imdoubtedly regarded himself as a theist. His theism, however, was of a decidedly liberal character, a judi- cious blending of positive and negative elements. He believed in God as the author or ground of the world, all-powerful, and possibly all-wise, but apparently indifferent to the individual wants of his creatures, and not the object of any affection. 2. Miracles. Hume defined miracles as events con- trary to the established laws of nature, and implied a distinction between external miracles, and internal. External miracles he did not admit to have taken place in the past, but he conceded the possibility of their taking place in the future— although not as the basis _of any popular system of religion. Internal miracles he asserted not only have occurred, but are occurring daily. His views on miracles and a particular Provi- dence, when he wrote both works, were the same. CONCLUSION. 307 3. A Future Life. On the question of the immor- tality of the soul, Hume's position, in the Treatise, seems to be positive ; in the Inquiry, on the other hand, it is negative. The change of statement, on this ques- ^ tion, was due to the author's desire to ohtain for the earlier work the favorable opinion of the learned world, or to his own conviction, as he grew older, that there was no valid ground— except possibly revelation — for belief in a future life, or most probably, to both these causes. Had Hume lived in the nineteenth cen- tury instead of the eighteenth, he would have ac- counted himself, like Huxley and Spencer, an agnostic on matters of religion. IV. Conclusion. If Hume is to be placed in some category — and as Hunt, with much truth, observed, no mind more than his "would have rebelled against being classed and labelled, ' ' — it may be said that, with regard to epistemology, he is a positivist ; with regard to metaphysics, he is a skeptic; and with regard to religion, he is an agnostic. On these three subjects— epistemology, metaphysics, and philosophy of religion, — the position of the In- quiry is practically identical with that of the Treatise. True, if the later book be taken by itself, and read independently of the earlier, because of omissions, it appears to be much the more positive. The Inquiry alone, however, not only gives a very inadequate con- ception of the philosophy of human nature, but also an essentially false one. Thus Kant, who was ac- quainted only with the later work,^ was entirely mis- taken regarding the author's position on certain im- portant epistemological questions. But the Inquiry 1 Cf. Adamson, The Philosophy of Kant, p. 202 n. 35. 308 Hume's treatise and inquiet. is the book whicli is by far the better known. More- over, it is the one which is generally regarded as con- taining the corrected, maturer, and truer statement of the principles of the science of man. It is un- doubtedly largely due to these circumstances that the treatment of Hume ia nearly aU the histories of phi- losophy is inadequate and defective. Hume's pe- culiar significance for the history of philosophy lies wholly and solely in the Treatise. In the preceding chapters of this monograph, we have endeavored to show that the Inquiry, when interpreted in the light of the Treatise, is essentially identical, both in point of view and in doctrine, with the earlier work. And that it should be so interpreted, we have also endea- vored to make manifest. The author more than once asserted that the philosophical principles, in both books, were the same. For some years after the pub- lication of the Treatise he looked forward to a second edition. In 1742, when his political essays were in great demand, he said that the Treatise of Human Nature was of "a more durable, though of a harder and more stubborn nature ' ' than the essays. He did not repudiate the Treatise until it had been attacked by Reid and Beattie. He was then an old man, too indolent, or too indifferent, or too busy with.practical affairs to defend it. Hence, he acknowledged that it w£is defective; but yet the imperfections lay in the form, not in the doctrine. Hume's philosophical principles remained ever the same. But his system, begun with the most extrava- gant expectations, was concluded in the most extreme disappointment. The philosophy of human nature was declared to be "the only solid foundation" of the CONCLUSION. 309 sciences, their "capital or center." But the Treatise "fell dead-horn from the press." The collapse, how- ever, was only temporary. The first offspring of Hume's mind lay for a time in a state of suspended animation. Then the weakling revived, grew, waxed strong, and soon became the enfant terrible of modem philosophy, a veritable hydra of- Lerna, one of the immortal works in epistemology. Hume's system has often been demolished, nay broken in pieces as a pot- per's vessel; but phcenix-Hke it always rises from the ruins, and assails its old enemy, dogmatism and ra- tionalism, with renewed vigor. This indeed, thus far, may be said to be its chief function, if not its only raison d' etre. Contrasted with his proud claims for his philos- ophy, at the beginning of his task, the author's sober estimate of its worth, on the conclusion of his work, is significant and instructive. "I assure you," he wrote to Hutcheson,^ "that without running any of the heights of skepticism, I am apt in a cool houj? to suspect, in general, that most of my reasonings will be more useful by furnishing hints and exciting people's curiosity, than as containing any principles that will augment the stock of knowledge that must pass to future ages." Progress in philosophy, as in other lines of thought, is the resultant of two contrary, but complementary forces: invention, and criticism. These are the two great intellectual powers that bear onward the life- giving light of civilization. And like the wings of the eagle, each is no less necessary to upward movement than is the other. Hume's mind, however, was crit- 1 Burton, Life, I, p. 118; of. I, p. 552. 310 Hume's treatise and dstquikt. ical, not constructive. He did not possess the inward eye of the poet, nor the spiritual vision of the prophet. He was constitutionally color-blind to some of the more important aspects of reality. But he had a supreme genius for destructiveness. His dialectic mind, like a logical machine, ground and analyzed with stoical indifference all thiags whatsoever, that fell within its relentless grasp. Letters and science, theology and medicine, law and politics;— all have had their great iconoclasts. But no department of knowledge has been more fortunate in this respect, than has been "divine philosophy," because of the resistless logic, and all-devouring criticism of Hume. APPENDIX A. OUTLINE OP THE RELATION OP THE TREATISE TO THE INQUIRY. A Treatise of Human An Inguiry concern- Nature. ing Himian Un- derstanding. Introduction to the § 1. Of the Different Spe- Treatise of Human cies of Philosophy; Nature. or Introduction to the theoretical part of the Treatise of Human Nature. Book I. Of the Understand- ing. Part I. Of Ideas, their Orig- in, Composition. Abstraction, Connec- ■ tion, etc. § 1- Of the Origin of our § 2. Of the Origin of Ideas. Ideas. [§ 2. Division of the Sub- ject.] [§ 3. Of the Ideas of the Memory and Im- agination.] § 4. Of the Connection § 3. Of the Association of or Association of Ideas. Ideas. 311 312 Hume's treatise and inquiet. [§ 5. Of Relations.] [§ 6. Of Modes and Sub- stances.] S 7. Of Abstract Ideas. paet n. Of the Ideas of Space and Time. §1-5. Of the Ideas of Space and Time. § 6. Of the Ideas of Ex- istence and Exter- nal Existence. §12. Of the Academical or Skeptical Phi- losophy. — ^Part II. §12. Of the Academical or Skeptical Phi- losophy. — ^Part n. §12. Of the Academical or Skeptical Phi- losophy. — Part I. Part IH. Of Knowledge Probability § 1. Of Knowledge. and § 2. Of Probability; and of the Ideas of Cause and Effect. § 3. Why a Cause is al- ways necessary. § 4. Of the Component Parts of our Eea- sonings concerning Causes and Effects. § 5. Of the Impressions of the Senses and Memory, § 4. Skeptical Doubts con- cerning the Opera- tions of the TJn- standing. — ^Part I. 4. Skeptical Doubts con- cerning the Opera- tions of the Un- standing. — Part 11. EELATION OP TREATISE TO INQUIET. 313 § 6. Of the Inference from § 5. the Impression to the Idea. § 7. Of the Nature of the § 5. Idea, or Belief. § 8. Of the Causes of Be- lief. [§ 9. Of the Effects of other Eelations, and other Hahits.] [§10. Of the Influence of Belief.] §11. Of the Probability of § 6. Chances. 12. Of the Probability of Causes. [§13. Of Unphilosophical Probability.] §14. Of the Idea of Neces- sary Connection. [§15. Eules by which to judge of Causes and Effects.] §16. Of the Eeason of Animals. Skeptical Solution of these Doubts. — Part I. Skeptical Solution of these Doubts. — Part n. Of Probability — Chances, and Causes. § 1. Of the Idea of Neces- sary Connection. [§ 8. Of Liberty and Necessity.] § 9. Of the Eeason Animals. [§10. Of Miracles.] of Part IV. Of the Skeptical and other Systems of Philosophy. Of Skepticism with §12. regard to Eeason. Of the Academical or Skeptical Philos- ophy. — ^Part n. 314 HUME S TREATISE AND INQUIET. § 2. Of Skepticism with regard to the [§3. §4. §5. Of the Ancient Phi- losophy.] Of the Modern Phi- losophy.] Of the Immateriality of the Soul. [§ 6. Of Personal Ident- ity.] § 7. Conclusion of this Book. §12. Of the Academical or Skeptical Philos- ophy. — ^Part I. §11. Of a Particular Providence and of a Future State. §12. Of the Academical or Skeptical Philos- ophy.— Part in. APPENDIX B. BIBLIOGEAPHY. I. Editions and Translations op the Treatise and Inquiry. 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