»asiU«a^teE,— ,^ B|IJiaiigW ili t a B)S ^toiW ii i^ >aa8^^Biaaiiiiifei><^^ iij i i i ii iim i i in nii i iiinii i iKiiilliiilHii Urittiiiiri ■Mali !«*!*?,«*/ /rvsua^/mi CORNELL UNIVERSITY LIBRARY Gift in memory of MARY STEPHENS SHERMAN, 13 from JOHN H. SHERMAN, '11 DATE DUE :^W- ^SP^ "C^ i;^.,,, „|,,.-| Jflft -.n»^.... .,^;.ttijtfttfTWl.lA(itf.>v*.. d 1 ^'b ..., - -..v ..w^.-nR^-.swi GAYLORD PRINTED IN U S.A. OUTLINES OF COSMIC PHILOSOPHY. VOLUME I. OUTLINES COSMIC PHILOSOPHY, BASED ON THE DOCTUINE OF EVOLUTION, CRITICISMS ON THE POSITIVE PHILOSOPHY. JOHN 1:1 SKE, M.A., LL.B., ASf^TSTANT LIBnABIAN, AND FORMERLY LECTURER ON PHILOSOPHY, AT HARVARD UNIVERSITY. ^'L'univers, pour qui sanraii I'enibrasser d'u)i seul point de vue, ne serait, sHl est permis de le dire, qiCunfait -unique et ^me grande verite," — D'Alembert. "Kal Th '6\ou rovTo diet ravra Koafiov KaKotabv^ ovk dKoa-fxlav." — Plato. IN TWO VOLUMES. VOLUME I. MACMILLAN AND CO. 1874. [Tlic Rirjhl of Translation rinr! Hrprodwiion is /'fjf>'i«', 1. LONDON: R. CLAY, SONS, AND TAYLOR, PRINTEES, BREAD STREET HILL. Ill ^I'id) TO GEORGE LITCH EGBERTS, M.A., IN REMEMBRANCE OF THE GOLDEN DATS WHEN, WITH GENEROUS AIMS IN COMMON, WE STUDIED PHILOSOPHT TOGETHER, AND IN CONSECRATION OF THE LIFELONG FRIENDSHIP WHICH HAS BEEN AN UNFAILING SOURCE OF JOT AND STRENGTH TO US BOTH, J ir^bkate i^in '§oah, Cornell University Library The original of this book is in the Cornell University Library. There are no known copyright restrictions in the United States on the use of the text. http://www.archive.org/details/cu31924092298011 PREFACE. The present work is based upon lectures given at Harvard University in the autunan of 1869 and spring of 1871, and afterwards repeated, wholly or in part, in Boston, New York, Milwaukee, and London. At the outset these lectures were designed to include only a criticism of the Positive Philosophy, and T had no intention of publishing them in anything like the shape in which they were originally written. It was only when — at the suggestion of Dr. E. L. Youmans, and through the kindness of Mr. Marble — the lectures were reported in the New York World, and seemed to meet the wants of a large number of readers, that I decided upon publishing them, and upon so enlarging the course as to make it include a somewhat complete outline- sketch of the new philosophy based on the Doctrine of Evolution. In coming to this decision, I was at first but carrying out a project, formed several years earlier, of writing a series of essays illustrative of Mr. Spencer's philosophy. But the work has grown on my hands, and in its present shape is something more than it was originally intended to be. For whUe it does not, as a whole, lay any claim to the character of an original work, it has never- theless come to contain so much new matter, both critical and constructive, that it can no longer be regarded as a mere reproduction of Mr. Spencer's thoughts. The new con- viii PREFACE. structive matter begins with the eighteenth chapter of Part II., which (together with its predecessor) was written m 1866, and which leads to conclusions concerning the relations of a social community to its environment, such as will doubtless be much more thoroughly and satisfactorily pre- sented by Mr. Spencer in his forthcoming work on Sociology. The following chapters on the Genesis of Man, along with considerable expository and critical matter, contain a theory as to the part taken by the prolongation of human infancy in originating social evolution, which is entirely new in all its features. With the exception of numerous minor suggestions scattered here and there throughout the work, these are the only parts of the constructive matter which I can claim as my own; though it may be interesting to observe that the chapter on the Evolution of Mind was mostly written, and the theory contained therein entirely worked out, before the publication of Part V. of the second edition of Mr. Spencer's " Principles of Psychology." The new critical matter is mostly to be found in the chapters relating to religion, and in the discussion of the various points of antagonism between the philosophy here expounded and the Positive Philosophy. Though the real work of demolishmg the undue pretensions of Positivism had already been well accomplished by Mr. Spencer, most of whose arguments are here reproduced, it seemed to me that much might still be done toward clearing up the dire confusion with which in the popular mind this subject is surrounded ; and this I realized the more keenly as it was some time before I had succeeded in getting clear of the confusion myself. Accordingly on every proper occasion the opinions characteristic of the Positive Philosophy are cited and criticized; and on every occasion they are proved to be utterly irreconcilable with the opinions characteristic of Mr. Spencer's philosophy and adopted in this work. The PREFACE. ix extravagant claim of Positivism to stand for the whole of attainable scientific philosophy is, I trust, finally disposed of when it is shown that a system of philosophy has been constructed, out of purely scientific materials and by the employment of scientific methods, which opposes a direct negative to every one of the theorems of which Positivism is made up. The phrase " Cosmic Philosophy," ^ by which I have pro- posed to designate this system, has not found favour with Mr. Spencer, who urges the objection that all philosophies whatever may, in a certain sense, be termed "Cosmic," inasmuch as all philosophies have had for their subject- matter the explanation of the universe or Cosmos. In this objection there would no doubt be much weight if any alternative term could be proposed which should be ideally perfect. As it is, I cannot but think that the alternative term suggested by Mr. Spencer is open to a parallel objection of at least equal weight. To the phrase " Synthetic Philo- sophy," as a distinctive epithet, it is an obvious objection that the systems of Aquinas and Hegel, and other systems built up by the aid of metaphysical methods, might claim to be entitled " Synthetic " as well as the system of Mr. Spencer. So far as this goes, therefore, there would seem to be but little room for choice between the two terms. But when we look more carefully into the matter, the case is seen to be otherwise. For , not only does the term " Cosmic," when regard is had to the implications of its primitive meaning, convey all that is conveyed by the term "Syn- thetic," but it further hits the precise point by which Mr. Spencer's philosophy is fundamentally distinguished alike from Positivism and from all ontological systems. For the ^ This term was first suggested to me by Mr. Manton Marble, some four years ago, though at that time neither he nor I could have appreciated it at its full value. X PREFACE. term " Cosmos " connotes the orderly succession of phenomena quite as forcibly as it denotes the totality of phenomena ; and with anything absolute or ontological, with anything save the "Mundus" or orderly world of phenomena, it has nothing whatever to do. So that, strictly speaking, no theological system of phHosophy can be called "Cosmic" while admitting miracle, special-creation, or any other denial of the persistence of force, into its scheme of things ; and no ontological system can be calkd "Cosmic" while pro- fessing to deal with existence not included within the phenomenal world. The term, therefore, forcibly distin- guishes Mr. Spencer's philosophy from systems which have contained ontological or theological assumptions. And, on tlie other hand, as is shown below, in the ninth and tenth chapters of Part I., it distinguishes it from Positivism ; since the latter philosophy consists of an Organon of scientific methods ancillary to the construction of a system of Sociology, and has always implicitly denied the practical possibility of such a unified doctrine of the Cosmos as Mr. Spencer has succeeded in making. In short, Mr. Spencer's philosophy is not merely a Synthesis, but it is a " Cosmic Synthesis ; " that is, it is a system which, without making appeal to data that are ontological or to agencies that are extra-cosmic, brings all known truths concerning the coexistence and succession of phenomena into relation with one another as the corollaries of a single primordial truth, which is alleged of the omnipresent Existence (ignored by Positivism) whereof the phenomenal world is the multi- form manifestation. To no other system yet devised can this definition be strictly applied ; and of no other system can we strictly say that it is " Cosmic." Along with these specific advantages, as characterizing Mr. Spencer's system of philosophy, the term "Cosmic" and its congeners possess sundry general advantages, as PREFACE. li characterizing that entire method or habit of philosophizing of which Mr. Spencer's system is in onr day the most conspicuous product. In this sense I have contrasted " Cosmism " with " Anthropomorphism " as two different fashions or habits of interpreting phenomena, the contrast being more specifically carried out, in the concluding chapters of this work, between " Cosmic Theism " and " Anthropomorphic Theism." For further justification and elucidation I must refer to the body of the work, where * these terms are introduced and defended as occasion requires. In view of all that is thus from time to time brought forward, I think it will appear, that a more strikingly characteristic terminology would be hard to find, or one in which so great a number of kindred dis- tinctions are expressed by so small a group of terms. But while it is incumbent on me to declare Mr. Spencer's disapproval of this terminology, it should be added that, so far as I know, the question at issue between us is purely a question of nomenclature, and is not implicated with any essential differences of opinion as to the character and position of the system of thought to which the nomenclature is applied. Without implying that Mr. Spencer should be held responsible for everything that is maintained in the following pages, I believe that the system here expounded is essentially his, and that such supplementary illustrations as I have added are quite in harmony with the fundamental principles which he has laid down. Much of the new critical matter thus appears to be concerned with questions of nomenclature and other ques- tions which hinge, directly or remotely, upon these. And considering how important are the "counters of thought," and how often they are made to do duty as its hard money, it will perhaps be felt that too much emphasis has not been laid upon these points. The rest of the new critical matter. xii PREFACE. as before hinted, occurs in Part III., where it is attempted to show that the hostility between Science and Eebgion, about which so much is talked and written, is purely a chimera of the imagination. Putting the case into other language, it may be said that to assert a radical hostility between our Knowledge and our Aspirations, is to postulate such a fundamental viciousness in the constitution of things as the evolutionist, at least, is in no wise bound to acknow- ledge. The real conflict, as I have sought to show, is not between Knowledge and Aspiration, but between the less- imperfect knowledge of any given age and the more-imperfect knowledge of the age which has gone before. Tor it lies in the nature of progress that the heresy or new-knowledge of yesterday is the orthodoxy or old-knowledge of to-day, and that to those who have learned to associate their aspirations with the old knowledge it may well seem im- possible, that like aspirations should be associated with the new. But the experience of many ages of speculative revolution has shown that while Knowledge grows and old beliefs fall away and creed succeeds to creed, nevertheless that Faith which makes the innermost essence of religion is indestructible. Were it not for the steadfast conviction that this is so, what could sustain us in dealing with questions so mighty and so awful that one is sometimes fain to shrink from facing their full import, lest the mind be overwhelmed and forever paralyzed by the sense of its nothingness ? Venice, April 16, 187i. C N T E N T S. PART I. PBOLEGOMENA. CHAPTER I. PAGE THE EELATIVITY OE KNOWLEDGE ... . ... 3 CHAPTER II. THE .SCOPE OF PHILOSOPHY . . .... 22 CHAPTER III. THE TEST OF TRUTH . 45 CHAPTER IV. PHENOHUSNON AND NOUMENON 72 CHAPTER V. THE SUBJECTIVE AND OB.JECTIVE METHODS ..... il7 CHAPTER VI. CAUSATION , . . . 146 CONTENTS. CHAPTER VII. i-AGR 132 ANTHROPOMOKPHISM AND OOSMISM CHAPTEE VIII. ORGANIZATION OF THE SCIENCES CHAPTER IX. PHILOSOPHY AS AN OKGANON . . . • • CHAPTEE X. COSMISM AND POSITIVISM CHAPTER 11. . 188 234 ; 25.5 CHAPTER XI. THE QUESTION STATED ... ... ... . 265 PART II. SYNTHESIS. CHAPTEE I. MATTER, MOTION, AND FOEOE 279 297 CHAPTER III. EVOLUTION AND DISSOLUTION 314 CHAPTER IV. THE LAW OE EVOLUTION 32(5 CONTENTS. XV CHAPTER V. PAGE rLANETABT EVOLUTION . . , ..... 356 CHAPTER VI. THB KVOLUTION OF THE EARTH . .... . . 398 CHAPTER VII. THE SOURCES OF TERRESTRIAL ENERGY 406 CHAPTER VIII. THE BEGINNINGS OF LIFE ... ... 418 CHAPTER IX. SPECIAL-OKBATION 0)' DERIVATION ? . . ... .... 438 ERRATUM. Vol. I. p. 63, line 19, insert "but" at the end of the line, after "sure.'' PAET I. PIIOLEGOMEXA. " Quare speculatio ilia Parmenidis et Platonis, quamvis in illis nuda fuerit speculatio, excelluit tamen : Omnia per scalam (juandam ad unitatem ascen- dere." — Bacon. "Das achbnste Gluck des denkenden Menschen ist das Eiforschliehc erforscht zii haben, unddas Unerforschliche ruMg zu verehren." — Goethb. A'OL. I. CHAPTEE I. THE RELATIVITY OF KNOWLEDGE. When we contemplate any portion of matter, such as a cubical block of metal or wood, it appears to our senses to be perfectly solid. No breach of continuity appearing anywhere among the aggregate of visual and tactual perceptions which its presence awakens in us, we are unable to restrain ourselves from imagining that its parts are everywhere in actual contact with each other. Nevertheless, a brief analysis of this opinion will suffice to show that it cannot be maintained without landing us in manifest absurdity. We need only recollect that every portion of matter is compressible, — may be made to occupy less space than before, — and that compressibility, implying the closer approach of the constituent particles of the body, is utterly out of the question, unless empty space exists between these particles. We are therefore obliged to admit that the molecules of which perceptible matter is com- posed, are not in immediate contact, but are separated from each other by enveloping tracts of unoccupied space. But no sooner do we seek refuge in this assumption than we are again met by difficulties no less insuperable than the one just noticed. The form of our experience of all objects compels us to postulate that cohesive or gravitative forces are continually urging the particles of matter toward closer 4 COSMIC PHILOSOPHY. [pt- i- union, while disruptive or thermal forces are continually urg- ing them toward wider separation. In view of this, suppose we regard matter, with E"ewton, as 'consisting of solid atoms, never°absolutely contiguous to each other, but always attract- ing or repelling each other with a force varying inversely as the squares of the distances between the atoms. What then is the constitution of these hypothetical atoms ? Are they divisible, or indivisible ? And if divisible, what shall we say of the parts into which they are divided ? Can these be again divided, and so on for ever ? If we say yes, we are speedily brought face to face with a double in- conceivability. For, on the one hand, by no effort of thought can we conceive the infinite divisibility of a particle of matter. Mentally to represent any such division would require infinite time. On the other hand, granting that the particles which we have postulated as the component units of matter are divisible, we have not escaped the difficulty which confi'onted us at the outset. For each of these particles, if divisible, is a piece of matter just like the block of metal or wood with which we set out, — only smaller in size. The particles of these particles cannot, as we have seen, be in direct contact ; then they must each be com- posed of several particles not in contact, but exerting on each other attractive and repulsive forces that vary inversely with the squares of their distances apart ; and again we have to ask of these particles, Are they divisible or indi- visible ? and so on, for ever. Such are the difficulties into which we are led if we assume that the atoms of which matter is composed are divisible. Let us now assume that (as their name implies) they are indivisible. And this is, no doubt, the assumption which is most congruous with the experiences of the chemist. Yet we shall find that an absolutely indivisible atom is quite inconceivable by human intelligence. Every such atom, if it exists, must have an upper side and an under side, a right side OH. i.j THE RELATIVITY OF KNOWLEDGE. 5 and a left side, or if spherical, must have a periphery that is conceived as covering some assignable area. Now by no effort of oiir intelligence can we imagine sides so close together that no plane of cleavage can pass between them ; nor can we imagine a sphere so minute that it cannot be conceived as divisible into hemispheres ; nor can we imagine a cohesive tenacity so great that it might not be overcome by some still greater disruptive force such as we can equally well imagine. When we contemplate the mode in which one particle of matter acts upon the adjacent particles by attractive and repulsive forces, we find ourselves equally puzzled. As Mr. Spencer well observes, " matter cannot be conceived except as manifesting forces of attraction and repulsion. Body is distinguished in our consciousness from space, by its opposi- tion to our muscular energies ; and this opposition we feel under the twofold form of a cohesion that hinders our efforts to rend, and a resistance that hinders our efforts to compress. Withou-t resistance there can be merely empty extension. Without cohesion there can be no resistance. Thus we are obliged to think of all objects as made up of parts that attract and repel each other ; since this is the form of our experience of all objects. Nevertheless, however verbally intelligible may be the proposition that pressure and tension everywhere co-exist, yet we cannot truly represent to ourselves one ultimate unit of matter as drawing another while re- sisting it." Nor is this the last of the difficulties which encumber our hypothesis of mutually-attracting and repelling particles separated by tracts of unoccupied space. For this hypothesis requires us to conceive one particle acting upon another through a space that is utterly empty ; and we can in no wise conceive any such action ? How shall we escape this difficulty? Shall we assume that the intervals between the particles are filled by a fluid of excessive tenuity, like the so-called imponderable ether to which physicists are in 6 COSMIC PHILOSOPHY. [ft. i- the habit of appealing? We shall soon find that the problem is only shifted. As soon as we inquire into the constitution of this hypothetical intermolecular fluid, we are no better off than before. For we have no alternative but to regard this fluid as itself an extremely rarefied form of matter : since it does not perceptibly affect the weights of bodies, we must regard it as possessed of a density that is almost infinitesimal,— that is, its constituent particles must be separated from each other by regions of empty space that are even greater in proportion to the size of the particles than are the spaces that intervene between the molecules of that relatively dense form of matter which we call ponder- able. With regard to the ether, as before with regard to the matter, we have to ask. How can its particles act upon each other through space that is utterly empty 1 How can a thing act where it is not ? How can motion be transmitted, in the absence of any medium of transmission ? and to this question no answer ever has been, or ever can be devised. Thus, whichever horn of the dilemma we take hold of, we are sure to be gored by it. Whether we assume on the one hand that matter is absolutely solid, or on the other hand that it is absolutely porous, we are alike brought face to face with questions which we can neither solve nor elude. If now we turn from the inquiry into the ultimate constitu- tion of that matter out of which the universe is formed, and inquire what was the origin of this universe, we shall find ourselves plunged into still darker regions of incomprehen- sibility. Eespecting the origin of the universe three verbally- intelligible hypotheses may be formed. We may say, with the Atheist, that the universe is self-existing ; or, with the Pantheist, that it is self-created ; or, with the Theist, that it is created by an external agency. Let us examine these three propositions severally, not with the view of determining which of them is true, but with the view of determining whether any one of ihem is comprehensible. CH. I.] THE RELATIVITY OF KNOWLEDGE. 7 Philosophically speaking, then, we must admit that, whether or not the Atheistic hypothesis of a self-existent universe be assumed as true, it is at any rate incomprehen- sible. We can form no genuine conception answering to the phrase "self-existence." For by self-existence we clearly mean existence which is not dependent on any extraneous existence ; which is not conditioned or determined by any cause. The assertion of self-existence is the denial of causa- tion ; and when we deny causation we also deny commence- ment, inasmuch as to suppose that there was a time when the existence commenced is to admit that the commencement of the existence was determined by some cause ; which is contrary to our hypothesis. In order, therefore, to conceive self-existence, we must conceive existence throughout infinite past time ; and to do this manifestly exceeds our powers. The Pantheistic hypothesis of self-creation is similarly in- comprehensible. Self-creation, equally with self existence, excludes the idea of any extraneous determining cause. If the passage of the universe from non-existence, or from potential existence, into actual existence, were determined by any extrinsic cause, manifestly it would not be self-created. Nevertheless, to suppose that existence, after remaining for a long period in one form, suddenly took on of its own accord another form, requires us to imagine a change without any cause, — which is impossible. Of the Theistic hypothesis, also, we must perforce admit, that, whatever may be urged in favour of our accepting it as a help to our thinking, it is no less incomprehensible than the other two. In the first place, the creation of something out of nothing is a process which we are wholly incapable of representing in thought. In the second place, granting that the universe was made from nothing by an external agency, we are compelled to ask whence came this agency? We must either admit for it another extrinsic cause still further back, and so on for ever; or we must regard it as self- 8 COSMIC PHILOSOPHY. [ft. i. existing, in which case we are again brought face to face with the same ultimate difficulties which attend upon the atheistic hypothesis. For, as Mr. Y. W. Newman observes, " a God uncaused and existing from eternity is quite as incomprehen- sible as a world uncaused and existing from eternity." Which conception is the more likely to be true, I repeat, does not for the present concern us. What we have now to notice is merely the incapacity of the human intellect for realizing either the one or the other. In spite of their great apparent diversity, the atheistic, pantheistic and theistic hypotheses all contain, in one form or another, the same fundamental assumption. Sooner or later they all require us to conceive some form of existence which has had neither cause nor beginning ; and to do this is impossible. Nevertheless, in spite of the impossibility of conceiving it, this fundamental assumption is one which we are com- pelled to adopt, unless we abstain from theorizing altogether upon the subject. For it is impossible to enter into any inquiry concerning causation without eventually postulating some First Cause. We are obliged to do so from sheer inability to follow out in thought an infinite series of causes. Assuming, then, the existence of a First Cause, let us inquire for a moment into its nature. The First Cause must be infinite. For if we regard it as finite, we regard it as bounded or limited, and are thus compelled to think of a region beyond its limits, which region is uncaused. And if we admit this, we virtually abandon the doctrine of causa- tion altogether. We therefore have no alternative but to regard the First Cause as infinite. We are no less irresistibly compelled to regard the First Cause as independent. For if it be dependent, that on which it depends must be the First Cause. The First Cause can therefore have no necessary relation to any other form of Being ; since if the presence of any other form of existence is necessary to its completeness, it is partially CH. I.] THE RELATIVITY -OF KNOWLEDGE. 9 dependent apon such other form of existence, and cannot be the First Cause. Thus the First Cause, besides being infinite must be complete in itself, existing independently of all relations, — that is, it must be absolute. To such conclusions, following the most refined meta- physical philosophy of the day, are we easily led. By the very limitations of our faculties, we are compelled to think of a First Cause of all phenomena ; and we are compelled to think of it as both infinite and absolute. Nevertheless, it will not be difficult to show that such a conclusion is utterly illusiA^e; and that in joining together the three conceptions of Cause, of Infinite, and of Absolute, we have woven for ourselves a network of contradictions more formidable, more disheartening than any that we have yet been required to contemplate. For, in the first place, that which is a cause cannot at the same time be absolute. For the definition of the Absolute is that which exists out of all relations ; whereas a cause hot only sustains some definite relation to its effect, but it exists, as a cause, only by virtue of such relation. Suppress the effect, and the cause has ceased to be a cause. The phrase "Absolute Cause," therefore, which is equivalent to "non- relative Cause," is like the phrase " circular triangle." The two words stand for conceptions which cannot be made to unite. " We attempt," says Mr. Mansel, "to escape from this apparent contradiction by introducing the idea of succession in time. The Absolute exists first by itself, and afterwards becomes a Cause. But here we are checked by the third conception, that of the Infinite. How can the Infinite become that which it was not from the first ? If causation is a possible mode of existence, that which exists without causing is not infinite ; that which becomes a cause has passed beyond its former limits." Eut supposing all these obstacles overcome, so that we might frame a valid conception of a Cause which is also 10 COSMIC PHILOSOPHY. [ft. Absolute and Infinite : have we then explained the origin of the universe ? Have we advanced one step toward explaining^ how the Absolute can be the source of the Eelative, or how' the Infinite can give rise to the Finite? To continue with Mr. Mansel, " if the condition of causal activity is a higher state than that of quiescence, the Absolute . ... has passed from a condition of comparative imperfection to one of comparative perfection ; and therefore was not originally perfect. If the state of activity is an inferior state to that of quiescence, the Absolute, in becoming a cause, has lost its original perfection. There remains only the supposition that the two states are equal, and the act of creation one of com- plete indifference. But this supposition annihilates the unity of the Absolute." These examples must suffice for my present purpose, which is to illustrate and enforce, at the beginning of our investiga- tion, the doctrine of the Eelativity of Knowledge. They constitute but a small, though an important, portion of the mass of evidence which might be alleged. The history of metaphysical speculation — if we leave out of the account all psychological inquiry, which is a very different matter — is little else than the history of a series of persistent attempts to frame tenable hypotheses concerning the origin of the universe, the nature of its First Cause, and the ultimate con- stitution of the matter which it contains. History teaches us that all such attempts have failed ; and furnishes us with ample inductive or empirical evidence that the human mind is incapable of attaining satisfactory conclusions concerning the First Cause, the Infinite, the Absolute, or the intimate nature of things. AVe accordingly say for brevity's sake that we cannot know the Absolute, but only the Eelative ; and in saying so, we implicitly assert two practical conclusions : — First, we cannot know things as they exist independently of our, intelligence, but only as they exist in relation to our intelligence. CH. I.] THE RELATIVITY OF KNOWLEDGE. 11 Secondly, the possibilities of thought are not identical or coextensive with the possibilities of things. A proposition is not necessarily true because we can clearly conceive its terms ; nor is a proposition necessarily untrue because it contains terms which are to us inconceivable.' This great truth, which I have thus illustrated by a few empirical examples, must now be illustrated deductively. It must be shown how the impossibility of knowing or con- ceiving anything save the Eelative results from the very constitution of our minds — from the very manner in which our thinking takes place. And this may be shown by several distinct lines of argument. In the first place, all hnoiving is classifying. What do we mean when we say that any given phenomenon has been explained ? We mean simply that it has been ranked along with similar phenomena which, having previously been grouped together, are said to be understood. For example, in walking out some clear November evening, your attention is arrested by a bright, but suddenly vanishing track of light across the sky, which you recognize as the appearance of a " falling-star." In doubt, perhaps, as to the true explana- tion of this phenomenon, you appeal to some astronomer, who tells you that a zone of planetary matter encircles the sun ; that the course of this zone, lying near the course of the earth's orbit and not being concentric with it, must intersect it at sundry points ; and that when, at certain seasons of the 1 Hence, as will appear more fully hereafter, we have no criterion of abso- lute or objective truth. But it will also appear that, in the realm of pheno- mena, with which alone are we practically concerned in forming the conclu- sions which make up our common-sense, our scieuce, and our philosophy, we do possess a valid criterion of relative truth in the test of inconceiv- ability. A proposition concerning phenomena, which contains an incon- ceivable term, is ipso facto a proposition without a basis in our experience of phenomena, and is accordingly inadmissible. But a proposition concerning noumena, which contains an inconceivable term, is entirely out of relation with experience, since we have no experience of noumena ; and wo have accordingly no means of judging whether it is true or not. This is what is meant by the statement in the text. 12 COSMIC PHILOSOPHY. [pt. i. year, such intersection occurs, the gravitative force of the earth pulls down some of the fragments constituting this zone, and unites them with its own mass. That is to say, hg ranks the phenomenon which is to be explained along with the more familiar phenomena of heavy bodies which circulate about a vast central mass, and which, by their gravitative power, draw to themselves whatsoever comes within a certain distance of them. And this you feel to be a perfectly satis- factory explancttion. Similarly, when Newton explained the manner in which these planets are kept revolving about the sun, he had recourse to the hypotheses of gravitation and tangential momentum. By the former he classified the unknown force which keeps the moon from flying away from the earth along with the familiar force which causes un- supported terrestrial bodies to fall toward the earth's centre. By the latter he classified the unknown force which keeps the moon from tumbling down upon the earth along with the familiar force which urges a stone whirled at a sling's-end to fiy away upon a tangent. In each case he did nothing but classify phenomena which had hitherto remained unclassified ; and this was rightly felt to be a triumphant explanation ; although the ultimate nature of the forces operating remained as mysterious as before. If now we proceed stiU further, and ask in what sense the force which makes apples fall can be regarded as known by us, — we can only reply, it is not known in itself, but only in its manifestations throughout a number of phenomena which can be classed together, and any one of which is said to be known when it is perceived to be like its congeners previously presented to our consciousness. We know a thing only when we classify it in thought with some other thing; only when we see it to be like some other thing. In short, cognition is possible only through recognition. In the infant, we may see that there are no cognitions until the feelings awakened by the presence of external objects have CH. i.j THE RELATIVITY OF KNOWLEDGE. 13 been arranged into groups, so that when certain sensations occur they may be recognized as belonging to such or such S group. And in the adult, as our examples already cited suffice to show us, an object is known just in so far as the impressions which it produces upon us can be assimilated to previous impressions. .Or if this is still not perfectly clear, a brief citation from Mr. Spencer wiU make it clear. " An animal hitherto unknown, though not referable to any established species or genus, is yet recognized as belonging to one of the larger divisions — mammals, birds, reptiles, or fishes ; or should it be so anomalous that its alliance with any of these is not determinable, it may yet be classed as vertebrate or invertebrate ; or if it be one of those organisms of which it is doubtfid whether the animal or vegetal char- acteristics predominate, it is still known as a living body ; even should it be questioned whether it is organic, it remains beyond question that it is a material object, and it is cognized by being recognized as such. Whence it is manifest that a thing is perfectly known only when it is in all respects like certain things previously observed ; that in proportion to the number of respects in which it is unlike them, is the extent to which it is unknown ; and that hence when it has abso- lutely no attribute in common with anything else, it must be absolutely beyond the bounds of knowledge." ^ The bearing of all this upon our main thesis is so obvious as to need but the briefest mention. Manifestly the First Cause, the Infinite, the Absolute, can be known only by being classified. We can conceive it at all only by conceiving it as of such or such kind — as like this or that which we have already conceived. There can be but one First Cause ; and this, being uncaused, cannot be classified with any of the multiplicity of things which are caused. The Infinite, again, cannot be conceived as like the Finite ; nor can it be classed with any other Infinite, since two Infinites, by mutu- 1 First Principles, p. 80. 14 COSMIC PniLOSOPHY. [pt. l. ally limiting each other, would become finite, and thus destroy each other. And likewise the Absolute cannot, without a manifest contradiction in terms, be regarded as sustaining a relation of likeness to anything else. For by the definition of the Absolute, it is that which exists out of all relation. Thus by the very constitution of the knowing pro- cess, we are for ever debarred from knowing anything save that which is caused, which is finite, and which is relative. If we start from another point of view, and contemplate the process of knowing under a different but correlative aspect, we shall be driven to the same inevitable conclusion. In order to know anything, we must not only recognize it as like certain other things, but we must recognize it also as different from certain other things. We cognize whiteness, not only by its likeness to the whiteness previously presented to our consciousness, but also by its difference from redness, blueness, or blackness. If all things were white we should have no knowledge of whiteness. To constitute an act of cognition, distinction is as necessary as assimilation. As Mr. Mansel has ably shown, " The very conception of con- sciousness necessarily implies distinction between one object and another. To be conscious, we must be conscious of something ; and that something can only be known as that which it is, by being distinguished from that which it is not. But distinction is necessarily limitation ; for if one object is to be distinguished from another, it must possess some form of existence which the other has not, or it must not possess some form which the other has." Accordingly, if we are to conceive the First Cause at all, we must conceive it as limited ; in which case it cannot be infinite : and we must conceive it as different from other objects of cognition; in which case it is relative, and cannot be absolute. Finally, we cannot know the Absolute, because all know- ledge is possible only in the form of a relation. There must be a Subject which cognizes and an Object which is cognized. CH. I.] THE RELATIVITY OF KNOWLEDGE. 15 The subject is a subject only in so far as it cognizes the object, and the object is an object only in so far as it is cognized by the subject. Eliminate either one, and the act of cognition is destroyed. Hence the Absolute, if it is to be known, must be an object existing in relation to a subject; it cannot be known in itself, but only in its relations to the knowing mind ; that is, it can be known only by ceasing to be the Absolute. Thus by whatever road we travel, we are brought up at last against the same impassable barrier. By no power of conception or subtilty of reasoning can we break down or undermine the eternal wall which divides us from the know- ledge of things in themselves. If we attempt to frame any hypothesis concerning their nature, origin, or modes of action, we find ourselves speedily checkmated by alternative im- possibilities. And if, resting in despair after all our efforts have proved fruitless, we inquire why this is so, we find that from the very organisation of our minds, we can frame no cognition into which there do not enter the elements of likeness, difference, and relation ; so that the Absolute, which presents none of these elements, is utterly and for ever unknowable. What is the meaning of this conclusion, when translated from the metaphysical language in which I have expressed it, into language that is somewhat more familiar 1 It means not only that the Deity, in so far as absolute and infinite, is inscrutable by us, and that every hypothesis of ours concerning its nature and attributes, can serve only to illus trate our mental impotence ; but it also means much more than this. It means that the Universe in itself is likewise inscrutable ; that the vast synthesis of forces without us, which in manifold contact with us is from infancy till the close of life continually arousing us to perceptive activity, can never be known by us as it exists objectively, but only as it affects our consciousness. It means, in short, that we 16 COSMIC PHILOSOPHY. [pt. i. cannot transcend the organically-imposed limits of our own intelligence. We do not know matter, but we know a group of coexistent states of consciousness which we call the perceptions of resistance, extension and colour, sound or odour. We do not know motion, but we know the group of sequent states of consciousness produced by minute alter- ations in the muscles of the eyes, or perhaps of the tactual organs, in the act of attending to the moving object. Nor do we know force, but we know continual modiKcations of our consciousness which we are compelled to regard as the manifestations of force. Nor do we even know consciousness absolutely and in itself : we know only states of conscious- ness in their relations of coexistence and sequence, likeness and unlikeness. Although this is one of the best-established conclusions of modern psychology, it is still a conclusion which requires considerable effort to understand in all its implications ; and for this reason, as well as on account of its supreme impor- tance, it will be desirable briefly to illustrate it from yet another point of view. We shall be assisted in comprehend- ing the general truth by a set of considerations which show that, although our internal feelings or states of consciousness are constantly produced by external agents, yet we have no warrant whatever for assuming that the external agent in any way resembles the internal feeling. For instance,, although the feelings of redness and resistance are caused by agencies without us, we have no warrant for assuming that the external cause of redness resembles the feeling of redness, or that the external cause of resistance resembles the feeling of resistance. In other words, we know redness and resistance only as phenomena, only as modifications of consciousness ; and although we are compelled to refer these phenomena to causes which exist externally and which would still exist if there were no minds to be affected by them, we are nevertheless unable to assert that these external causes — CH. I.] THE RELATIVITY OF KNOWLEDGE. 17 the real things corresponding to the phenomena of redness and resistance, — are in any wise like the phenomena. To any one accustomed to examine these matters, such a conclusion seems much like a truism ; amounting, indeed, merely to the statement thal^ we c annot get oujtsidej)f_pur ownjninds. Nevertheless, it will perhaps not be considered a needless prolonging of the argument if I add a few concrete illustrations. In the first place, it is extremely probable that the kinds of feeling awakened by the same external cause are not quite alike in any two species of animals. When Wieniawski plays his violin in the Music Hall, his human auditors have awakened in them those feelings which we designate as the consciousness of musical sound ; but if he were to play his violin over a tank containing a number of those nioUusks which have no organs of hearing, the feelings awakened in them would be wholly different. They would feel a sort of nervous shiver or jar, like that which our fingers experience when holding a vibrating tuning-fork ; and they would very likely all shrink into their shells. In like manner, the same external agents which arouse well-defined tactual feelings in us, can arouse in a lobster, whose feet and claws are encased in a bony shell, nothing but that vague sort of tactual feeling of which we are conscious when we poke things with a stick. In the second place, it is extremely probable that the sub- jective feelings awakened by the same external cause are not quite alike in any two individirals of the same species. In those persons who are troubled with Daltonism, or colour- blindness, luminous undulations so different as those of red and green awaken feelings that are identical. On the other hand, "aerial pulses recurring at the rate of 16 per second, are perceived by some as separate pulses ; but by some they are perceived as a tone of very low pitch. Similarly at the other extreme. Vibrations exceeding 30,000 per second, are in- A'OL. I. c; 18- COSMIC PHILOSOPHY. [pt. i. audible through certain ears ; while through ears that are, as we may suppose, of somewhat unlike structures, these rapid vibrations are known as an excessively acute sound." i And thirdly, let us notice a set of facts which are so familiar to us that we overlook their significance. "A whiff of ammonia, coming in contact with the eyes, produces a smart ; getting into the nostrils, excites the consciousness we describe as an intolerably strong odour; being condensed on the tongue, generates an acrid taste ; while ammonia, applied in solution to a tender part of the skin, makes it burn, as we say." " A vibrating tuning-fork, touched with the fingers, gives them a sense of jar ; held between the teeth, it gives this same sense to the parts in which they are em- bedded, while by communication through the bones of the skull, its vibrations so affect the auditory apparatus as to awaken a consciousness of sound — a consciousness which alone results, if the tuning-fork does not touch the body." " The sun's rays falling on the hand cause a sensation of heat, but no sensation of light ; and falling on the retina cause a sensation of light, but no sensation of heat.'' Note that in all these cases the same external cause produces widely- different phenomena according to the different avenues through which it affects our consciousness. The external cause cannot resemble all these phenomena, its effects ; we do not know which it resembles ; what warrant have we, then, for assuming that it resembles any one of them ? To these examples, culled from Mr. Spencer's " Principles of Psychology," let me add another, which, though less obvious, is equally striking. The compound solar ray, when analysed, is found to consist of three sets of relatively simple ^ "It is probable that the antennas of insects respond to stimuli which leave us insensible, while stimuli which affect us leave them undisturbed. . . . We know there are a thousand tremcurs in the air which beat upon our ears unheard ; and if more sensitive organs are capable of hearing some of these, there must be treniours which no organism can feel." — Lewes, Prohlcms of Life, mid Mind, vol, i. p. 255. cii. I.] THE RELATIVITY OF KNOWLEDQE. 19 rays. First, we have the visible rays of medium refrangi- bility, rauging from red to violet, and sometimes called the ISTewtonic rays. Beyond the violet, in the outlying portions of the spectrum, lie the so-called Ritteric rays, of greatest refrangibility, which are not visible, but are manifested through their actinic or chemical effects ; these are the rays with which we photograph. Beyond the red, at the other end of the spectrum, lie the so-called Herschellic rays, of least refrangibility, which also are not visible, but are mani- fested through their thermal effects. These invisible rays differ from the visible physically, only by their different periods of motion or wave-lengths, in which respect the visible rays differ also among themselves, as is indicated by their different colours. Bearing this in mind, let us con- template the remarkable series of effects produced in oar consciousness by gradually increasing rates of vibration in the particles of matter. Vibrations occurring less frequently than 16 times in a second, produce in us the consciousness of a succession of noises. Vibrations which occur oftener than 16 times, but less often than 30,000 times, in a second, produce in us the consciousness of musical notes, which are higher and higher in pitch as the vibrations are more rapid. Vibrations occurring oftener than 30,000 times, but less often than 458,000,000,000,000 times, in a second, do not affect us through the ears, but the more rapid ones affect us through the nerves of the skin, and produce in us the consciousness of heat. Vibrations occurring at the rate of 458,000,000,000,000 in a second, affect us through the eyes, and produce in us the consciousness of red light ; at the rate of 577,000,000,000,000 in a second, they produce in us the consciousness of green light ; at the rate of 727,000,000,000,000 in a second, tliey produce in us the consciousness of violet light. At still higher rates than this, they cease to affect us through the eyes, and indeed produce in us no definite state of conscious- ness at all, though they may be remotely concerned in keep- c 2 20 COSMIC PHILOSOPHY. \y^- i- ing up that vague organic feeling of Uen-etre or pleasurable existence, which is in part due to the indirect effects of the Kitteric portion of the solar rays upon the chemical actions going on throughout our bodies. Here, then, we have one and the same external agency— vibrations among particles of matter— producing in us feelings so different as those of sound, heat, and light. And when it is asked which of these feelings the external cause resembles, is not the answer sufficiently obvious that in all probability it resembles none of them, and is comparable with none of them ? May we not clearly see that what appears to us as a series of widely-distin- guished phenomena may after all correspond to a set of objective realities between which there is no such wide distinction ? And do we need any more evidence to convince us that phenomena — by which I mean the effects produced upon our consciousness by unknown external agencies — are all that we can compare and classify, and are therefore all that we can hnoio ? Perhaps, however, it may still appear that, in the illustra- tion just cited, we have assumed a knowledge of the external cause, to a certain extent. In asserting that the feelings of sound, of heat, and of light, are alike caused by vibrations among particles of matter, we may perhaps seem to imply that we do know these vibrations, and we may be suspected of formulating the various states of consciousness in question, in terms of the objective reality.i But a moment's reflection will convince us that this is not the case. After the illustration with which this chapter opened, it is hardly necessary to say that the knowledge of a vibration of particles as an objective reality, is utterly unattainable by us. We reach the concep- ^ In his paper on " Hiljernicisms in Pliilosophy " {Omitemporary Revieio, January 1872, p. 1J7), the Duke of Argyll himself commits the following exquisite bull : — " We now know what light is ' in itself — that is to say, we know the nature and constitution of it, not in terms of the sensation it gives to us, but in terms of a wholly different order of coneeptimi." The italics are mine. CH. [.] THE RELATIVITY OF KNOWLEDGE. -21 tion of a vibration of particles only by inference from the states of consciousness aroused in us by visible or palpable vibrations. Certain subjective experiences of undulatory movement, as when a pebble is dropped into still water, or as when a string is made fast by one end and twitched at the other, beget in us the conception of vibration ; and this con- ception we transfer in thought to those molecules and atoms of which we believe material bodies to be constituted. So far, then, from interpreting our feelings of light, heat, and sound, in terms of the objective reality, we have merely been inter- preting certain states of consciousness in terms of other states. Or, to put the same statement into different language, we have regarded the phenomena of sound, heat, light, and actinism, as adequately explained, when we have classified them with certain other phenomena of vibratory motion. We merely affirm that a cause which, under a given set of conditions, will produce certain states of consciousness within us, will, under a different set of conditions, produce certain other states of consciousness. Concerning the nature of the cause, whether we call it vibration, or are content to go on calling it heat or light, we affirm nothing, and can know nothing. CHAPTEE II. THE SCOPE OF PHILOSOPHY. In setting forth and illustrating the conclusion that we can only know that which is caused, which is finite, and which is relative, we have virtually rejected as impracticable and use- less a large number of the inquiries with which philosophy has habitually concerned itself Both by practical examples, and by a series of mutually-harmonious deductions from the mode in which our intelligence works, as revealed to us by psychologic analysis, it has been shown that we are for ever debarred from any knowledge of the Absolute, the Infinite, or the Uncaused ; that we can affirm nothing whatever concern- ing the ultimate nature of Matter or Mind ; and that all our knowledge consists in the classification of states of conscious- ness produced in us by unknown external agencies. ISTever- theless from the earliest times, philosophy has busied itself in attempts to reach tenable conclusions respecting the nature and attributes of the absolute and infinite First Cause ; it has ever tacitly assumed that the ultimate nature of Matter as well as of Mind constitutes a legitimate subject of investiga- tion ; and that from the knowledge formed by the organized experience of recurring states of consciousness, we can in some mysterious way rise to a so-called higher grade of knowledge, in which realities no less than phenomena may CH. ii.J THE SCOPE OF PHILOSUFIIY. 23 become the object of thought. The earliest philosophic speculations of the Greeks dealt almost exclusively with the origin of the Universe, and the nature of its irpooTrj dp-)(fi or First Cause, or with just such theories of the ultimate constitution of matter as we saw in the previous chapter leading us to alternative impossibilities of thought. In the Parnunicles and Sophistes of Plato we may find, presented with unrivalled acuteness, though rendered dreary by endless verbal quibbling, many of the same inquiries concerning the nature of the Absolute which we have been led to condemn as impracticable. Is the Absolute One or Many ? Is the One Finite or is it Infinite ? And these inc[uiries, in the first- named dialogue, lead up to the same sort of startling paradoxes which we have already signalized as the inevitable outcome of speculation upon such subjects. In his first argument, Parmenides demonstrates that the One is neither in itself nor in anything else, neither at rest nor in motion, neither the same with itself nor different from itself. In his second argument, he demonstrates that the One is both in itself and in other things, both at rest and in motion, both the same with itself and different from itself That is, while his first demonstration denies both of two opposite and mutually destructive propositions, his second affirms them both. There is no doubt that after Plato's time the Greeks felt, though they did not distinctly comprehend, the futility of such inquiries. By the successors of Plato, philosophy was brought into a state of more or less complete scepticism as to the possibility of any trustworthy knowledge whatever. " We assert nothing, — not even that we assert nothing," was the extravagant dictum of one of the later schools of Greek philosophy. And finally philosophy ceased from its indepen- dent inquiries, being merged in theology by Proklos, who, hopeless of attaining absolute knowledge by any exertion of the intellectual powers, was driven to assert the existence of a divine supernatural light, by which the soul being 24 COSMIC PHILOSOPHY. [n. i. irradiated might thus alone catch glimpses of the external reality. The later career of philosophy furnishes us with the same kind of illustrations as its earlier stages. After its revival in the Middle Ages, philosophy again proceeded to treat of the same kind of questions as those which had baflled the keenest and most subtle intellects of antiquity. In the eager scrutiny of the nature of things, the scholastic metaphysicians thought little of ascertaining the relations of coexistence and succession among phenomena. Their disputes were about quiddities, entities, occult virtues, and efficient causes. Nor in modern times do we findthat philosophy has been at all disposed to recognize the limits which we have here found ourselves obliged to impose upon it. On the other hand, modern metaphysicians have generally proceeded upon the tacit assumption that the possibilities of thought are co- extensive with the possibilities of things, and that anj' train of propositions which can be clearly conceived and logically concatenated, must be true. It was upon this assumption that Malebrauche founded his theory of Occasional Causes, and Leibnitz his doctrine of Pre-established Harmony. It was upon this that Spinoza constructed a theory of the universe, the most gigantic in conception, and the most unflinchingly logical in execution, of all metaphysical theories. Upon this also, rests the Kantian doctrine of Necessary Truths ; and upon this most treacherous foun- dation has been more recently built the lofty but unstable structure of Hegelism. Since Bacon's time, it is true, there have appeared — for the most part in England — a number of eminent thinkers,- who, asserting the relativity of human knowledge, and avowedly renouncing the attempt to solve the mysteries of objective existence, have occupied themselves with psychological pro- blems. To these thinkers — Hobbes, Locke, Berkeley, Hume, Hartley, Brown, James Mill, Hamilton, and Mansel — a large en u.J THE SCOPE OF PHILOSOPHY. 25 proportion of the couceptions now current and dominant in philosophy are due. Nevertheless, as we shall see by and bye, even these philosophers have not always made their practice coincide with their preaching. Though they have asserted, and were indeed the first to assert clearly, the doctrine of the Eelativity of Knowledge, they did not always carry in their minds its full' import ; and were betrayed not unfrequently into making statements which imply that the possibihties of thought are coextensive with the possibiKties of things. It may appear, therefore, that in our rigorous denial of the possibility of absolute knowledge, we shall not have the countenance of the most eminent philosophers who have lived. It may be thought that their works will testify against us. We shall perhaps be accused of regarding the noble labours of so many generations of gifted thinkers as a mere imprac- ticable striving after that which no striving can procure, — as the crying of infants for the moon, or as the groping of the alchemist for the philosopher's stone. And it will no doubt be indignantly asked, by what title do we pretend to philo- sophize at all 1 In rejecting as for ever insoluble so large a proportion of the inquiries with which philosophy has until lately busied itself, do we not virtually declare philosophy to be antiquated and useless ? To neither of these accusations can we consent to plead guilty. In replying to the first, it may indeed be granted that those who rigorously maintain that Absolute Being is unknowable, will naturally regard the labours of Plato and Spinoza, and Hegel, as a vain seeking after that which cannot be found. But it does not follow that such seeking is to be condemned as worthless. It was only after many attempts had failed, that we could learn that the failure was due not to curable but to incurable weakness.^ It was only after all 1 "The study of the master-minds of the human race is almost equally instructive in what they achieved and in what they failed to achieve ; and speculations which are far from solving the riddle of existence have their use in teaching us why it is insoluble."— Manse], Metaphysics, p. 23. 26 COSMIC PHILOSOPHY. [pt. i. possible devices of attack had proved fruitless, that we could realize the truth that we had been assailing an inexpugnable fortress. Had we not been taught by many a bitter defeat, we should never have learned the real extent of our powers. Had not metaphysics reared many an apparently-solid edifice, which fell into unshapely ruin at the first rude blast of criticism, psychology might never have troubled itself to examiae the soil upon which all such edifices must be founded. Nay, it may be truly said, that though philosophers have failed in what they have consciously attempted, they have nevertheless unwittingly achieved a result greater than any of those which they have sought to obtain. By their long career of heroic defeat, they have furnished us with a concrete demonstration, almost superfluously ample, of the relativity of human knowledge. By exhausting all possible hypotheses respecting the objective reality, they have made it apparent that no tenable hypothesis can be framed. In the very failure to obtain one kind of truth, they have demonstrated for us a truth of another sort, — a truth which must for the future lie at the bottom of all successful research. Is not this then a worthy result ? Eemembering how steep and laborious is the path of human progress, is not the definite establishment of one fundamental truth like the Eelativity of Knowledge an achievement worthy to crown the efforts of twenty-five centuries ? Shall it take two or three generations of weary experimenting to bring into existence some incarnation of material force like the steam- engine, and may it not take a hundred generations for the human mind to ascertain for itself experimentally what it can know and what it cannot know ? To the second accusation we may return a straightforward denial. In asserting the impossibility of acquiring absolute knowledge, or of ascertaining aught respecting the nature of mind and matter and the origin of the universe, we do not dethrone Philosophy ; we do not condemn it as antiquated CH. 11.] THE SCOPE OF PHILOSOPHY. 27 and useless ; we do not leave it nothing with which to occupy itself. On the contrary, we do but enthrone it more securely than ever ; and we leave it in possession of quite as goodly a realm as that in which our metaphysical predecessors M'ould fain have established it. In order to show how this can be true, it will be necessary for me to define, somewhat at length, the Scope of Philosophy, — to indicate the nature of the inquiries with which philosophy may profitably be concerned. And since philo- sophy may be correctly though rudely defined as a kind of knowledge, it will first be desirable to indicate the essential distinctions between the different orders of knowledge, — to show in what respect philosophy differs from science, and in what respect both philosophy and science differ from that comparatively imperfect kind of knowledge wliich is the common property of uncultivated minds. Though science has been often vaguely supposed to be something generically distinct from ordinary knowledge, yet the briefest consideration will suffice to show us tliat this is not the case, but that scientific knowledge is only a higher development of the common information of average minds. In the first place we shall see that the process gone through, and the results attained by the process, are not generically different in scientific and in ordinary thinking. All knowledge whatever is, as we have seen, a classifica- tion of experiences. No intelligence or intelligent action is possible unless the distinctions among surrounding phenomena be detected and registered in the mind. Even the lowest animal can only preserve its existence on condition that different external agencies shall affect it in different ways,— that different sets of circumstances shall cause it to put forth correspondingly different sets of correlated actions. Perhaps it is sufficient for these simply constituted creatures to distinguish between the organic and inorganic matters present in their environment, or between light and darkness, as we 28 COSMIC PHILOSOPHY. [ft. i. see a freshwater polyp seek the darkest corner of a vessel exposed to direct sunlight. Among the higher animals possessed of developed organs of sense and of relatively- complex nervous systems, the classifying process is carried to much greater completeness. Along with a tolerably wide set of distinctions between various classes of plants and weaker animals that are more or less useful and desirable as food, and between various classes of inorganic phenomena that are serviceable or dangerous, and of stronger animals that are to be dreaded as enemies, — there is also a clear perception of the distinct modes of action involved in the acquisition of desired objects, and in the escape from menacing dangers ; forming an aggregate of knowledge which implies quite an extensive comparison and classification of ex- periences. Besides all this, there is a set of special distinc- tions between special orders of phenomena, between the various kinds and degrees of sound, odour and temperature, which in some cases exceed in discriminative accuracy any of the corresponding empirical distinctions which the human mind is able to recognize. And in the dog, who has from time immemorial been the friend and servant of man, there is superadded to all this a rudimentary moral classification of actions as praiseworthy or blameworthy, as is seen, for instance, in his guilty attitude when detected in committing a raid upon some neighbouring sheepfold. Coming lastly to man, but little illustration will be needed to show that his acquisi- tion of knowledge is in like manner the progressive establish- ment of distinctions. The supremely important knowledge which we acquire during early infancy consists in the mental grouping of objects according to their various properties ; in the gradual recognition of distinctions between hardness and softness, sweetness and acidity, rigidity and elasticity, rough- ness and smoothness, humidity and dryness, roundness and angularity, — between various shades and intensities of temper- ature, of sound, and of colour, — between matter which resists cii. ii.j THf'J SCOPE OF PHIL080FI1Y. 29 and space which does not resist. Later in life, our intellectual education consists still in the progressive grouping of ex- periences. That portion of it which we habitually designate as practical consists in the more and more complete distribu- tion of ends (as variously desirable or undesirable), and of the relations between ends and means ; while the education wliich we more especially characterize as theoretical consists in the more and more complete distribution of our acquired notions into well-defined groups, mathematical, physical, or physiological, legal or ethical. He who has so distinctly classified his experiences of the connections between certain courses of action and the resulting feelings of happiness or misery that he can usually decide upon any line of conduct with a clear perception of its consequences, is what we call a prudent man, or a man of sound judgment. While, as Mr. Mill has somewhere observed, that man is most completely educated who has the clearest sense of the connotations of the words which he uses ; who understands most thoroughly and feels most keenly the fine shades of distinction between allied groups of conceptions, which less perfectly educated persons are liable to confuse together and to reason about as if they constituted but a single group. Such a man possesses what Sainte-Beuve calls the sense of nuance ; an intellectual characteristic which is, perhaps, nowhere more habitually exemplified than in the charming pages of that most con- summate of critics. And this leads me to observe — what indeed the whole of the above survey implies — that since knowledge is classifica- tion, the completeness of the classification varies with the degree of intelligence. Minds in a low stage of development can distinguish only between widely-contrasted phenomena. The classifications of which they are capable consist of but few groups, indefinite in their extent and incoherent in their materials; while the' progressive increase of intelligence consists in the progressive establishment of sub-classes of 30 COSMIC PHILOSOPHY. [pt. i. phenomena, that are continually less and less widely con- trasted, that are more and more accurately defined in their limits and more and more coherent in their materials. And the ultimate perfection of knowledge would be the recogni- tion of all the distinctions which exist between phenomena, and the consequent establishment of classes whose members would be completely alike among themselves, while unlike the members of all other classes. Manifestly such knowledge would be, in the fullest sense of the term, scientific knowledge ; which is thus seen to be merely a higher and more complex development not only of the knowledge of ordinary matters which we do not regard as scientific, but of the rudimentary knowledge possessed by infants, by savages, and by the lower animals. The dog or lion has no doubt established in his mind the distinction between the bright sky of day, illuminated by a single dazzling orb, and the pale sky of night, spangled with a multitude of twinkling points. The savage who in his nocturnal prowlings guides himself by the stars has rudely classified these objects in their relations of position. The shepherds of Mesopotamia and ihe agriculturists of Attika superadded the distinctions between stars which regularly traverse the same apparent paths and stars which pursue an erratic course ; and in their classifications of stars according to their times of rising and setting we have an example of a rudely-scientific method of proceeding. Finally by the modern astronomer the heavenly bodies are minutely classified according to their mutual relations as suns, planets, or satellites ; according to their visible magnitudes, or the angles which they subtend on the field of vision ; according tu their orbital courses, their angular velocities, their axial inclinations, their specific gravities, etc., wherever these have been ascertained ; and lately in some few instances, according to their physical con- stitutions in so far as light has been thrown upon this point by spectrum-analysis. In like manner the lowest saA^age en. II.] THE SCOPE OP PHILOSOPHY. 31 has noted the wide contrast between plants and animals ; and in each of these great groups has furthermore made sub-classes comprising respectively those which are useful as food or as medicine for wounds, and those which are to be shunned as poisonous or otherwise dangerous. While, on the other hand, the scientific naturalist divides and subdivides until he acquires distinct conceptions of thousands of species of insects, and ranks trees in separate classes according to the myriad-fold shapes of their leaves, the spiral arrange- ment of their branches, the number of their cotyledons, or the mode of disposition of their woody fibre. All this will appear in a still clearer light when we remember that the various processes which we habitually group together under the name of " reasoning '' are all of them acts of classification. "The savage, having by ex- perience discovered a relation between a certain object and a certain act, infers that the like relation will be found in future cases." . . . When in consequence of some of the properties of a body, we attribute to it all those properties in virtue of which it is referred to a particular class, the act is an act of inference. " The forming of a generalization is the putting together in one class all those cases which present like relations ;■ while the drawing a deduction is essentially the perception that a particular case belongs to a certain class of cases previously generalized. So that, as classifi- cation is a grouping together of like things, reasoning is a group- ing together of like relations among things. And while the perfection gradually achieved in classification consists in the formation of groups of objects which are completely alike, the perfection gradually achieved in reasoning consists in the formation of groups of cases which are completely alike." ^ Since knowledge consists in classifying, it follows con- versely that ignorance consists in inability to classify — in the failure to group together similar phenomena ; and that 1 S-pencei-'s &says, 1st series, p. 189. 32 COSMIC PHILOSOPHY. [pt. i. error consists in wrongly classifying, in the grouping together of phenomena which are really distinct. When we say that a child is ignorant that nitric acid will burn, we mean that he has never ranked together the like cases of a finger immersed in nitric acid and a finger thrust against heated metal. When we say that the ancients were in ignorance concerning the force which keeps the planets in their orbits, we mean that they did not know what that force is like — that they had never grouped together the like cases of the earth attracting the moon and the earth attracting an apple. And when we say that they were in error in attributing the moon's motion to the volition of a presiding goddess, we mean that they grouped together the unlike cases of the motion of a heavenly body through the sky and the motion of a chariot driven by its charioteer along the ground. So when we say that we do not fully understand the coronal flames and other singular phenomena presented by the eclipsed sun, we mean that we have not yet entirely suc- ceeded in grouping them with other phenomena of which we have heretofore had experience. And when we say that we cannot now or at any future time know the Absolute, we mean that there is not now and never can be, anything given in cur experience with which we can classify it. Having thus, at the risk of tediousness, shown in detail the essential identity of the processes involved in science and in ordinary knowledge, let us go on to enumerate the respects in which science differs from ordinary knowledge, bearing in mind as we proceed that such distinctions can only hold good to a certain extent. They are not differences of kind, but differences of degree. In the first place we may say that science differs from ordinary knowledge in its power of quantitative prevision — of assigning beforehand the precise amount of effect which will be produced by a given amount of cause. Mere prevision is not, as is sometimes assumed, peculiar to science. We CH. n.J THE SCOPE OF PHILOSOPHY. 33 frequently hear it assigned, as the distinguishing charac- teristic of scientific knowledge, that it enahles us to predict ; and the infallibility of the predictions of science is commonly alluded to as among its greatest triumphs. Nevertheless, when the schoolboy throws a stone into the air, he can pre- dict its fall as certainly as the astronomer can predict the recurrence of an eclipse ; but his prevision, though certain, is rude and indefinite. The servant-girl has no need of chemistry to teach her that, when the match is applied, the fire will burn and smoke ascend the chimney ; but she is far from being able"to predict the proportional weights of oxygen and carbon which will unite, the volume of the gases whicli are to be given off, or the intensity of the radiation which is to warm the room. Her prevision is qualitative, not quanti- tative in its character : she can foresee the kind of effect, but not its amount. A moment's reflection, however, will show us that this statement, as it stands, does not convey the whole truth. It is not quite true that our servant-girl can foresee the kind of effect. She can foresee a part of it : she can tell us that the wood will burn, but she will know nothing about the union of oxygen with carbon ; and will thus illustrate the super- iority of science even with respect to qualitative prevision. On the other hand, she can, after a rude fashion, foresee the amount of effect which will follow her proceedings ; since she can, if intelligent, estimate the amount of fuel which will be required to produce a comfortable warmth. So the savage can estimate the amount of tension which he must impart to his bow in order to send his arrow to the requisite distance. Thus we see that, even with respect to quantitative prevision, science can be distinguished from ordinary know- ledge only by the superior accuracy and greater extent to which it carries such prevision. Just this same difference of degree between science and ordinary knowledge constitutes also the chief difference between the more developed and the VOL. I. ° 34 COSMIC PHILOSOPHY. [pt. i- less developed sciences. The sciences which have arrived at the highest perfection are those which have carried quan- titative prevision to the farthest extent. Between astronomy, which can foretell the precise moment at which a solar eclipse will begin a hundred thousand years hence, and meteorology, which cannot surely foretell from week to week the state of the weather, there is an almost immeasurable difference in scientific completeness. The chemist can pre- dict the exact quantity of effect which will be produced by mingling a new substance with any given compound, the properties of which have been studied; while the physio- logist cannot surely predict the exact amount of effect which will be produced by a drug that is introduced into the organism; and we accordingly consider chemistry a much more advanced science than physiology. And lastly, let us note that the date which we habitually assign for the com- mencement of any science is the date at which its previsions began to assume a definitely quantitative character. Dyna- mics is said to have become a science when Galileo deter- mined the increment of velocity of falling bodies. Chemistry became a science when Lavoisier, De Morveau, and Dalton discovered the exact proportions in which the most im- portant chemical combinations take place. ISTo science of heat was possible imtil the invention of the thermometer enabled men to measure the degrees of temperature. There was no science of optics until it had been ascertained that the sines of the angles of incidence and reflection or refrac- tion bear to each other a constant ratio. And with Mr. Joule's discovery that a certain number of degrees of heat is equivalent to a certain amount of mechanical motion, there becomes possible a science of thermodynamics which shall express by a single set of formulas the activities of forces hitherto treated as generically different. The second difference of degree between science and ordinary knowledge consists in the greater remoteness of the CH. II.] THE SCOPE OF PHILOSOPHY. 35 relations of likeness and unlil^eness which science detects and classifies. The child who, when an orange is presented to him, infers that on sucking it he shall experience a pleasant taste ; the savage who, finding the half-eaten carcass of a sheep, concludes that a lion has been in the neighbourhood; and Leverrier, who, noticing that the ob- served motions of Uranus do not coincide with its motions as predicted, suspects the existence of a still remoter planet which disturbs it — go, all of them, through what is essen- tially the same process. The child has mentally grouped together the attributes of an orange ; and when certain members of the group — as the shape and colour — are after- wards presented to his consciousness, there occurs a mental representation of the remaining member — the agreeable taste. The savage, from direct or hearsay experience, has grouped together many cases of the eating of sheep by lions, and from the presence of a certain number of the customary phenomena, he classifies this new case with his already- formed group of cases ; he assigns for the phenomenon a cause like the causes which he has known. The astro- nomer has linked indissolubly in his mind the phenomena of celestial motions with the phenomena of gravitative force, and has grouped many cases in which such force, brought to bear on a planet from different quarters, causes irregularities of motion. When, therefore, in the instance before him, after calculating the resultant of all the known forces in operation, he finds a residuum of motion which is unac- counted for, what does he do ? He infers a like force as the cause of the residuary motion ; and since there is no force without matter, he infers the existence of planetary matter other than the planetary matter already taken into account. He enlarges his group of cases in which planets perturb each other's courses, by admitting a hypothetical like case ; and forthwith proceeds to calculate, from the amount of residuary motion, the size, distance, and orbit of the unknown planet. D 2 36 COSMIC PHILOSOPSY. [pt. i. Nothing can better illustrate the statement that scientific and ordinary knowledge are alike in kind, -while different in degree. While the processes gone through by the child, the savage, and the astronomer, are manifestly the same, the immeasurable difference in the complication of the processes is equally manifest. While the inference in the one case is made instantaneously, so as almost to seem a part of the original perception, and while it admits of verification by a series of simple acts, — in the other case the inference is one which depends ultimately upon a long chain of dependent propositions, and the task of verifying it mathematically is exceedingly complicated and difficult. Thus to our state- ment, that science differs from ordinary knowledge in the definitencss of its previsions, we have to add that it differs also in the remoteness and complexity of its previsions. Thirdly, science differs from ordinary knowledge in the greater generality of the relations which it classifies. And this continuous increase in generality is one of the most striking characteristics of advancing science, "From the particular case of the scales, the law of equilibrium of which was familiar to the earliest nations known, Archimedes advanced to the more general case of the unequal lever with unequal weights ; the law of equilibrium of which includes that of the scales. By the help of Galileo's discovery con- cerning the composition of forces, D'Alembert established for the first time the equations of eqixilibrium of any system of forces applied to the different points of a solid body — equa- tions which include all cases of levers and an infinity of cases besides." But, as Comte observes, "before hydrostatics could be comprehended under statics, it was necessary that the abstract theory of equilibrium should be made so general as to apply directly to fluids as well as s':'lids. This was accomplished when Lagrange supplied, as the basis of the whole of mechanics, the single principle of virtual velocities," — or the principle that whenever weights balance each other, CH. 11.] THE SCOPE OF PHILOSOPHY. 37 " the relation of one set of weights to their velocities equals the relation of the other set of velocities to their weights." So geometry in ancient times treated of questions relating to particular figures ; but since the great discovery of Descartes, it has dealt with questions relating to any figure whatever. So, in the progress of analytical mathematics, we have first arithmetic which " can express in one formula the value of a particular tangent to a particular curve ; " and, at a later date, algebra, which can express in one formula the values of all possible tangents to a particular curve ; and, at a stUl later date, the calculus, which can express in one formula the values of all possible tangents to all possible curves.^ Fourthly, science is continually more and more clearly differentiated from ordinary knowledge by the continually increasing abstractness of the relations which it classifies. This proposition is involved in the preceding one. For clearly the progress towards higher and higher generality is the progress towards a knowledge more and more inde- pendent of special circumstances — towards a study of the phenomena most completely disengaged from the incidents of particular cases. And finally science differs from ordinary knowledge in its higher degree of o7'ganization — in the far greater extent to which it carries the process of coordinating groups of like orders of relations, and subordinating groups of higher and lower orders of relations. This we habitually regard as such a fundamental characteristic of scientific knowledge that we grant the title of science to some departments of inquiry which possess it, in spite of the fact that the only prevision which is possible in them is neither certain nor quantitative. Take, for instance, the case of biology. If quantitative pre- vision were the only thing which distinguishes science, we could hardly pretend to possess a science of life. Our power of prevision in biology is for the most part strictly limited to 1 Spencer's Assays," 1st series, pp. 177—180. 38 COSMIC PHILOSOPHY. [pt. i. the kind of effect which will follow a given cause ; it is seldom, if ever, that we can foretell the precise amount of effect ; and even with respect to the kind of effect, we cannot always be sure beforehand. Biology is not an exact science, like chemistry, and perhaps never will be. Nevertheless, biology is such an admirably organized body of truths ; its classification, both of objects and of relations, has been carried to such a considerable extent ; and the subordination, the mutual coherence and congruity of its verified proposi- tions is so striking ; that we should no more think of doubting its claims to be called a science than we should doubt the claims of astronomy. Thus we may end our comparison of scientific with unscien- tific knowledge. Along with generic identity between the two, we have noted five points of gradational difference. We have seen that science and common knowledge alike consist in the classification of phenomena in their relations of co- existence and sequence. But we have also seen that science differs from common knowledge in its superior power of quantitative prevision, in the remoteness, the generality, and the abstractness of the relations which it classifies, and in the far more complete mutual subordination and coherence of its groups of notions. Such are the distinctive marks of science, regarded as a kind of knowledge. What now are the distinc- tive marks of philosophy, regarded as a kind of knowledge ? The metaphysical philosophers, whose conclusions, methods, and postulates were rejected in the preceding chapter, would have replied to the above question, that philosophy is generi- cally different from science, — that philosophy is the know- ledge of the absolute, the infinite, the uncaused, the objective reality, while science is the knowledge of the relative, the finite, the caused, the subjective state, — that while the latter can concern itself only with phenomena, or things as they exist in relation to the percipient mind, the former can aspire to the knowledge of noumena, or things as they exist inde- CH. ti.] THE SCOPE OF PHILOSOPHY. 39 pendently and out of relation to the percipient mind. Such would have been their answer. But we have seen that no such knowledge of noumena is possible, that the very nature of the cognitive process precludes any such knowledge, and that, if philosophy is to be regarded as knowledge at all, it can have no such scope and function as metaphysicians have assigned to it. "What scope is there left for philosophy ? Tf, like science and common knowledge, it is nothing more than a classification of phenomena in their relations of coexistence and sequence, what is there left for it to do which science cannot do as well ? We reply that science can, after all, deal only with par- ticular orders of phenomena. No matter how vast the gene- ralities to which it can attain, it only proclaims truths which hold throughout certain entire classes of phenomena. It does not proclaim truths which hold throughout all classes of phenomena. Its widest truths are astronomic, or chemical, or biological truths ; they are not Cosmic truths, in the fullest sense of that expression. For by science we mean merely the sciences, — the sum of knowledge obtained by systematic inquiries into the various departments of phenomena. Such knowledge is, after all, only an aggregate of parts, each of which is more or less completely organized in itself: it is not an organic whole, the parts of which are in their mutual relations coordinated with each other. Or, to put the same truth in another form : — The universe of phenomena is an organic whole, the parts of which are not really divisible, though we must needs separate them for convenience of study. We find it necessary to pursue separate lines of in- vestigation for gravitative, or thermal, or chemical, or vital, or psychical, or social phenomena ; but in reality these phenomena are ever intermingled and interactive. Let us, for example, arrive at the widest possible generalization respect- ing astronomic phenomena ; we have still not constructed a body of doctrine concerning the universe, but only concern- ing a portion of it. It is only when the deepest truths 40 COSMIC PHILOSOrHY. [pt. i. respecting physical, chemical, vital, psychical, and social phe- nomena come to be regarded as corollaries of some universal truth — some truth common to all these orders of phenomena — that such a body of doctrine becomes possible. Such a body of doctrine is what we call philosophy in dis- stinction from science. While science studies the parts, philosophy studies the whole. While science, in its highest development, is an aggregate of general doctrines, philosophy, in its highest development, must be a Synthesis of all general doctrines into a universal doctrine. When Lagrange, by his magnificent application of the principle of virtual velocities to all orders of mechanical phenomena, fused into an organic whole the various branches of mechanics which had hitherto been studied separately, this was a scientific achievement of the highest order. When Grove and Helmholtz, by showing that the various modes of molar and molecular motion can be transformed into each other, furnished a common basis for the study of heat, light, electricity, and sensible motion, the result, though on the very verge of philosophy, still remained, on the whole, within the limits of science. But when the principle of virtual velocities and the principle of the correl- lation of forces were both shown to be corollaries of the prin- ciple of the persistence of force— were both shown to be necessitated by the axiom that no force is ever lost— then the result reached was a philosophical result. So when Von Baer discovered that the evolution of a living organism from the germ-cell is a progressive change from homogeneity of struc- ture to heterogeneity of structure, he discovered a scientific truth. But when Herbert Spencer applied Von Baer's for- mula to the evolution of the solar system, of the earth, of the totality of life upon its surface, of society, of conscious intel- ligence, and the products of conscious intelligence, then he discovered a truth in philosophy,— a truth applicable not merely to one order of phenomena, but to all orders. These illustrations, however, do not bring out distinctly CH. Ti.] THE SCUPE OF PHILOSOPHY. 41 enough the point ■which I am endeavouring to elucidate. The difference between philosophy and science, like the difference between science and common knowledge, is a difference in degree only. But the distinction is nevertheless a broad one, and as such is somewhat understated in the foregoing para- graph, because the examples there cited on the side of science are all taken from that transcendental region of science in which its problems begin to have implications almost as universal as the problems of philosophy. Thoroughly to estimate the character of the distinction, we shall do well to start somewhat further down, and note what the science is which is contained in text-books or in original monographs. Viewed from this stand-point, a science like biology, for example, has for its subject-matter questions concerning the changes undergone by starch or fibrine within the stomach, the distribution of cells and fibres in the tissue of the brain, the relations of blood-supply to the functional activity of any organ, the manner in which the optic nerve is made to respond diversely to rays of different refrangibility impinging upon the retina, or the growth of bone from sundry centres of ossification starting here and there in the primitive cartilage ; or again such questions as concern the generic or ordinal relationships of barnacles, or bats, or elephants, the homologies between a bird's wing and a dog's fore-leg, the geographical distribution of butterflies, or ferns, or pine-trees, the typical structures of vertebrates or annulosa, or the kinships between fossil forms of the horse and pig. In these questions, and a thousand others like them, we see at once that we are in the special domain of biology, and that our reasonings belong unmistakably to science, and not to common knowledge on the one hand, or to philosophy on the other. If now, after mastering countless details of this sort, we go on to inquire into the cause of the bilateral symmetry of lobsters and centipedes, or of the spiral arrangement of leaves around a stem; if we seek to generalize the phenomena of heredity, 42 COSMIC PHILOSOPHY. [pt. i. or hybridity, or adaptation, or, if we endeavour, with Mr. Darwin, to determine the agency of natural selection in modifying the characteristics of species ; we are still no doubt within the territory of science, but we have arrived at a region in which the inquiries take so wide a sweep, and the results have so immediate a bearing upon other inquiries outside of biology, that our study may seem to demand some especially descriptive name. Accordingly we find the phrase " transcendental biology " employed by French writers, and elsewhere we meet with the signiiicant title " philosophical biology." Still more significantly Mr. Spencer, whose treatise on biology is occupied with researches of this high order, speaks of them as constituting a domain of " special philo- sophy." That is to say, just where this science has reached the widest genercdity consistent with its being called biology at all, it is characterized as a special kind of philosophy. But one more step is needed to reach the level of that philosophy which need not be qualified as special. If, pursuing the same line of advance, we proceed — as I shall hereafter do — with the aid of the most general principles of heredity, adaptation, and natural selection, to elucidate some com- prehensive theory of life ; and if we contemplate this theory of life, on the one hand, as dependent on certain universal laws of matter, motion, and force, and on the other hand, as furnishing a basis for sundry doctrines relating to intellectual, moral, and social phenomena ; then we have clearly come into the domain of philosophy, strictly so called. And the result would have been the same had we started from astronomy, or physics, or any other science; save that nowhere else, perhaps, could the true character of the process have been so fully illustrated as in the case of biology — the great central science upon the theorems of which so closely depend the views which we must hold concerning ourselves and our relations to the universe about us. That such transcendental inquiries as those last mentioned CH. 11.] THE SCOPE OF PHIJjOSOPHY. 43 belong strictly to philosophy, and constitute the aU-essential part of it, can be questioned by none save those who, with Hegel, would make philosophy synonymous with ontology. Upon these it is incumbent, if they would establish their position, to dispose of the facts and reasonings which have made the relativity of all knowledge the fundamental theorem of modern psychology. For us it may suffice to point out that the province of philosophy, as here defined, includes all such inquiries into cosmology, into psychology and ethics and religion, as philosophers have occupied themselves with in the past, excepting those only in which the necessary limita- tions of human thinking have been expressly or tacitly ignored. Far from dethroning philosophy, we are assigning to it a scope as wide as was recognized for it by the early Greeks; while in approaching its problems, we are enabled to profit by that physical investigation which Sokrates not unjustly stigmatized, in his own day, as hopelessly mislead- ing, but which now, conducted upon sounder methods, is our surest guide to the knowledge of truth. Thus is philosophy vindicated, and its function is seen to be as important as that of science. Eejecting, as we were compelled to dp, the metaphysical assumption tliat philosophy is a kind of knowledge generically distinct from all other kinds, and asserting for it a common root with science and with ordinary knowledge, we have nevertheless seen that it differs from the two latter, much in the same way that the one of them differs from the other. Accurate quantitative pre- vision is, in the nature of things, confined to the most special of the special inquiries with which science is concerned. Limited as it is to individual cases occurring under general laws, it must be left on one side in enumerating the distinc- tive features of philosophy. But from what has been brought forward, it at once appears that philosophy differs from science in the greater generality, abstractness, and remoteness of the relations which it formulates, and also in its larger and 44 COSMIC PHILOSOPHY. [pt. i. more complex organization of general truths into a coherent system. Or, to sum iip by a set of rough and general, though not severely accurate, contrasts (which, after all the foregoing explanation, we may safely do) : — Common Knowledge ex- presses in a single formula a particular truth respecting a particular group of phenomena ; Science expresses in a single formula a general truth respecting an entire order of pheno- mena ; Philosophy expresses in a single formula a universal truth respecting the whole world of phenomena. Philosophy, therefore, remains, as of old, the study of the Cosmos,— save that it is the study of phenomena not of noumena, of evolution not of creation, of laws not of purposes, of the How ? not of the Why ? CHAPTEE III. THE TEST OF TRUTH. Having now indicated the limits of human knowledge, and marked out the province of that most highly organized kind of knowledge called philosophy, it becomes us next to inquire what are the sources of knowledge, and what is its guaranty ? What is the test of truth which our philosophy shall recognize as valid 1 And first, what is Truth ? Truth may be provisionally defined as the exact corre- spondence between the subjective order of our conceptions and the objective order of the relations among things. Now since by the very constitution of the knowing process we are debarred from knowing things in themselves, since our highest philosophy must for ever concern itself with phe- nomena and can never hope to deal with objective realities, the question arises, how can we ever ascertain the objective order of the relations among things ? How can we compare this objective order with the subjective order of our concep- tions? And without such comparison, how can we ever be certain that the two orders correspond ? Can we then ever hope to possess an objective canon of truth ? And if we cannot obtain any such canon, are we not irresistibly driven to Idealism or to Scepticism, — to the philosophy which denies the existence of any objective reality, or to the philosophy which denies that truth can be attained at all ? 46 COSMIG PHILOSOPHY. [pt. t. Such questions as these have arisen whenever in the long career of philosophic inquiry an approach has been made toward demonstrating the relativity of knowledge. They dictated the criticisms of Leibnitz upon Locke's doctrine that all knowledge is the result of experience. The Cartesians had postulated the existence of innate ideas ; a postulate which was destroyed when Locke showed that there can be no ideas until the mind has come into contact with environ- ing agencies. But to Locke's reassertion of the scholastic formula, N^ihil est in intdledu quod noji prius in sensii, Leib- nitz added the important qualification, 7iisi intellectus ipse. Eejecting, equally with Locke, the Cartesian doctrine of innate ideas, recognizing fully that there can be no know- ledge until the mind has been awakened into activity by the presence of objects to be cognized, Leibnitz nevertheless maintained that in each act of cognition there is an element furnished by the mind as well as an element furnished by the environment, — that the subject is not passive, but co- operates actively with the object. In all this, let us note, there is nothing that conflicts with the established doctrine of the relativity of knowledge. It will be remembered that in our first chapter the necessary cooperation of subject and object in every act of cognition was shown to be one of those very facts which enforce the conclusion that aU. know- ledge is of the Eelative. No competent psychologist would now subscribe to the Lockian opinion that previous to the reception of experiences the mind is like a blank sheet. Physiology has taught us better than that, — has taught us that mind is strictly correlated with a complex nervous sys- tem, which, according to minute peculiarities of organization, modifies the experiences resulting from its intercourse with environing agencies. We, therefore, recognize as fully as Leibnitz, that the subject actively cooperates with the object in each act of consciousness. And we insist that, for that very reason, our knowledge, being the product of subjective CH. III.] THE TEST OF TRUTH. 47 and objective factors, can never be regarded as a knowledge of the objective factor by itself. This is, indeed, the import of our illustration, above given, from the phenomena of vibra- tory motion. Since a homogeneous phenomenon, like the undulation of molecules, can produce in us such hetero- geneous states of consciousness as the feelings of sound, heat, or colour, we argued that the constitution of the percipient mind must modify in every case the character of the phe- nomenon perceived ; and that, therefore, the phenomenon cannot be regarded as like the external noumenon, its part- cause. What is this but saying, with Leibnitz, that the subject actively cooperates with the object in each act of conscious knowledge ? The Leibnitzian criticism, therefore, only serves to bring out in a stronger light the doctrine that all knowledge is of the Eelative. Though powerful against the hypothesis of Locke, it is powerless against the position held by modern psychology. Such a result, however, was the farthest possible from Leibnitz's thoughts. Far from intending to re-enforce the doctrine of relativity as shadowed forth in the writings of the Lockian school, his object was to crush it at the start by showing that we can obtain a criterion of absolute or objective knowledge. And he accordingly gave to his state- ment an interpretation quite inconsistent with the doc- trine of the relativity of knowledge as we are now obliged to hold it. He held that in many acts of cognition, the mind contributes an element of certainty which could never have been gained from experience, which could never have flowed from the intercourse of the mind with its environment ; and that propositions obtained by such acts of cognition are Necessary Truths, — truths which are true of the objective order of things as well of the sub- jective order. After Hume, by drawing out the Lockian doctrine to its extreme corollaries, had enunciated a set of conclusions which 48 COSMIC PHILOSOPHY. [pt. i. deny all that the doctrine of relativity explicitly denies, but which differ from the doctrine of relativity in ignoring what the latter implicitly asserts, the LeiLnitzian theorem was again taken up by Kant, who made it his own by his manner of illustrating it, and whose arguments on this topic still carry conviction to the minds of many able metaphysicians. The immense importance of Kant's views makes it desirable for us to give them some farther consideration than is im- plied in merely stating them. In the first place, it must be borne in mind that Kant maintained, no less stoutly, and perhaps no less consistently, than Hume, the doctrine of the relativity of all knowledge. As Mr. Lewes truly observes, " the great outcome of the Kritik was a demonstration of the vanity of ontological specu- lation." Kant would have repudiated Schelling and Hegel, as he did in fact openly repudiate the claims of Fichte to be considered his legitimate successor and expounder. It was Kant who first showed that every hypothesis which we can frame respecting the Absolute, the Infinite, the First Cause, or the ultimate essences of things; must inevitably commit us to alternative impossibilities of thought. It was Kant also who showed psychologically, from the necessary coopera- tion of subject and object in each act of cognition, that a knowledge of the pure object as unmodified by the subject is for ever impossible. Kant held that a phenomenon, inas- much as it is an appearance, presupposes a noumenon — a thing which a-p-pears, — but this noumenon, which is a neces- sary postulate, is only a negation to us. It can never be positively known ; it can only be known under the conditions of sense and understanding, ergo, as a phenomenon. " And accordingly," says Kant, " though the existence of an external world is a necessary postulate, its existence is only logically affirmed." Of its existence out of relation to our conscious- ness we can know nothing ; and it consequently appears that ' we can never predicate of oiir knowledge that it has objec- cii. III.] THE TEST OF THUTH. 49 tive truth." ^ Even so, reiterates Kant, in the introduction to the Kritik, "to. attempt to transcend the sphere of the subjective is vain and hopeless ; nor is it wise to deplore that we are ' cabin'd, cribbed, confined ' within that sphere from which we never can escape. As well might the bird, when feeling the resistance of the air, wish that it were in vacuo, thinking that there it might fly with perfect ease. Let us there- fore content ourselves with our own kingdom, instead of cross- ing perilous seas in search of kingdoms inaccessible to man." Up to this point we may regard Kant as equally with Hume the precursor of the modern philosophy of relativity. In the above conclusions there is little to which Hume would have objected. But when we come to examiae the Test of Truth set up by the two great adversaries, the point of irreconcilable antagonism between them becomes apparent. Though conducted with a wider historic experience, and with more extensive psychologic resources, the combat was essen- tially the same which had been waged in the preceding epoch between Leibnitz and Locke. Hume had said : the. sole criterion of truth is uniformity of experience ; that to which human experience has invariably testified, we are compelled to accept as true ; though it may not be true of the pure objective order of things, it is true for us, — true of the order of things as presented to our intelligence. Kant, on the other hand, distinguished between contingent and necessary truths ; and asserted that while uniformity of experience is a suffi- cient criterion of contingent truth, it is not a trustworthy criterion of necessary truth. For experience, says Kant, can tell us that certain phenomena always occur in certain rela- tions ; but it cannot tell us that they rrmst always so occur. Uniformity of experience cannot assure us that two and two must make four, or that two straight lines cannot enclose a space. We cannot conceive that these things should be other- wise, and we must therefore know them, independently of ' Lewes, Ristonj of Pliilosopliy, Srd edition, vol. ii. pp. 471, 472. VOL. I. E 50 COSMIC PHILOSOPHY. [pt- i- experience, and by the very constitution of our minds, ihis element of necessity and universality is the element which the mind furnishes in the duplex act of cognition. This theorem contains two assertions, the one implicit, the other explicit. It asserts implicitly that the subjective element in cognition can be isolated from the objective element, at least so far as to be independently defined. It asserts explicitly that absolute uniformity of experience is inadequate to produce in us the belief in the necessity of any given relation among phenomena. With reference to the first of these assertions, I shall be content with citing the excellent remarks of Mr. Lewes : — "There was an initial misconception in Kant's attempt to isolate the elements of an indissoluble act. It was one thing to assume that there are necessarily two coefficients in the function; another thing to assume that these could be isolated and studied apart. It was one thing to say, Here is an organism with its inherited structure, and apti- tudes dependent on that structure, which must be consi- dered as necessarily determining the forms in which it will be affected by external agencies, so that all experience will be a compound of subjective and objective conditions; another thing to say, Here is the pure d priori element in every ex- perience, the form which the mind impresses on the matter given externally. The first was an almost inevitable con- clusion ; the second was a fiction. Psychology, if it can show us anything, can show the absolute impossibility of our dis- criminating the objective from the subjective elements. In the first place, the attempt would only be possible on the ground that we could, at any time and in any way, disengage Thought from its content ; separate in Feeling the object as it is out of all relation to Sensibility, or the subject as pure subject. If we could do this in one instance, we should have a basis for the investigation. The chemist who has learned to detect the existence of an acid by its reactions in one case, CH. III.] THE TEST OF TRUTH. 51 can by its reacbions determine it in other cases. Having experience of an acid and an alkaloid, each apart from the other, he can separate them when finding them combined in a salt, or he can combine them when he finds them separate. His analysis and synthesis are possible, because he has else- where learned the nature of each element separately. But such analysis or synthesis is impossible with the objective and sub- jective elements of thought. Neither element is ever given alone. Pure thought and pure matter are unknown quan- tities, to be reached by no equation. The thought is neces- sarily and universally subject-object ; matter is necessarily, and to us universally, object-subject. Thought is only called into existence under appropriate conditions ; and in the objec- tive stimulus, the object and subject are merged, as acid and base are merged in the salt. When I say that the sensation of light is a compound of objective vibrations and retinal susceptibility, I use language which is intelligible and ser- viceable for my purpose ; but I must not imagine that the external object named vibration is the Ding an sich, the pure object out of all relation to sensibility ; nor that the retinal susceptibility is pure subject, involving no vibratory element. Kant himself would assure me that the vibrations were as subjective as the susceptibility. Indeed, seeing that he denied altogether the possibility of a knowledge of pure object, the Ding an sich, it was a violent strain of logic to conclude that in thought he could separate this unknowable object from the subject knowing it." ^ A violent strain of logic it was, no doubt. After proving, almost to superfluity, that subject and object are inseparably united in each act of cognition, and after triumphantly using this fact against the ontologists who pretended to a knowledge of the objective reality in itself, Kant turns around and teUs us that we may after all acquire a knowledge of the subjective reality in itself ! Though we can never determine what the ' Lewes, History of Philosophy, 3rd edition, vol. ii. p. 483. E 2 52 OOSMIG PHILOSOPHY. [pt. i- environment furnishes in the duplex act of cognition, we can none the less determine exactly what the mind furnishes. By this wonderful inconsistency Kant opened the way for the later German idealism. Through this inlet entered Fichte, Schel- ling, and Hegel, with their swarm of mediasval conceptions, to perturb the onward course of philosophy. Kant might in vain protest. It was in vain that " he showed that the sub- jective d priori nature of these truths was peremptory proof of their objective falsehood ; that they could not be truths of things, precisely because they were purely subjective con- ditions of thought." Once granted that the subject could of itself possess truth independent of experience, independent of intercourse with the objective environment, the inference was inevitable that the subject might impose its necessities upon the object, that the possibilities of thought ndght be rendered coextensive with the possibilities of things. Thus Kant, after laboriously barring out ontology at the main entrance, carelessly let it slip in at the back door. Thus, by admitting the possibility of arriving at truth otherwise than through experience, did he render nugatory his elaborate demonstration of the relativity of knowledge.^ This will appear still more evident as we proceed to examine the second portion of Kant's theorem, — the assertion that uniformity of experience, however long continued, can never afford us a sufficient guaranty of necessary truth. The argument here is at first sight a plausible one. Any parti- cular experience can only tell us that a phenomenon, or a 1 " The truth is," says Mr. Lewes, in his new work just now appearing, ' ' Kant tried to hold contradictory positions. The whole drift of his polemic against the ontologists was to show that knowledge was limited, relative, and could not extend beyond the sphere of possible experience ; but while thus cutting the ground from under the ontologists, he was also anxious to cut the ground from the sensationalists and sceptics, and therefore tried to prove that the Mind brought with it an d priori fund of knowledge." — Problems of Life and Mind, vol. i. p. 463. In the present chapter I quote by preference from Mr. Lewes, because it seems to me that he has illustrated both the sti;fngth and the weakness of Kant's position (and thus, virtually, of all modern metaphysics) more thoroughly and more clearly than any other critic. CH HI.] THE TEST OF TBUTH. 53 relation between phenomena, is thus and thus; not that it must be thus and thus. And any number of experiences can only tell us that certain phenomena have hitherto always occurred in certain relations ; not .that they must always and for ever occur in the same relations. Or, as Dr. Brown phrases it, " Experience teaches us the past only, not the future." Let us take as an illustration, our belief that every event must universally and necessarily have a cause, — that no change can ever take place anywhere without an antecedent. This is what the Kantian would call a necessary truth. And the Kantian would say. All that experience can tell us is, that in an immense number of instances, and in an immense number of places, every event which has occurred has had a cause. It cannot tell us that in all future instances, and in all x^laces throughout the universe every event must have a cause. To test such a belief by experience would require that our experience should be extended through infinite time and infinite space, which is, of course, impossible. Without such infinite and eternal experience we can never be sure that, sooner or later, somewhere or other, some event will happen without a cause, and thus overturn our belief Never- theless, we have such a belief — an invariable and invincible belief. And since our limited experience cannot have pro- duced such a belief, it must have arisen in us independently of experience ; it must be necessitated by the very constitu- tion of our thinking minds; and must therefore be universally and necessarily true. Such is the Kantian argument. Upon all this it is an obvious comment, that, if the belief in the universality of causation is an inherent belief neces- sitated by the very constitution of our thinking minds, it is a belief which ought to be found wherever we find a thinking mind. It is hardly necessary to say that this is not the case. Children, savages, and other persons with undeveloped powers of reasoning believe in particular acts of causation, but not in the universality of causation — a conception which is too 84 COSMIC PHILOSOPHY. [pt. i. abstract for their crude intelligence to grasp. Nay, I have known educated people who maintained that there might be regions of the universe where the law does not hold, and who thought it hardly safe to deny that even on our own planet events might occasionally happen without any determin- ing antecedent. Besides which, all those who still accept the doctrine of the so-called "Freedom of the Will," impli- citly, and sometimes explicitly, assert that the entire class of phenomena known as volitions are not causally determined by groups of foregoing circumstances. The belief in the universality of causation was certainly not prevalent in antiquity, or in the Middle Ages ; its comparative prevalence in modern times is due to that vast organization of expe- riences which we call physical science; and even at the present day it is not persistently held, except by those who are accustomed to scientific reasoning, or to the careful analysis of their own mental operations. But this argument does not strike to the root of the matter, for though the belief in the universality of causation is not a universal belief, the belief in its necessity in each particular case is undoubtedly universal. And, as we have seen, the Kantian denies the power of accumulated experience to produce the belief that the future must inevitably resemble the past. He reminds us that for many ages it was supposed that all swans were white, until finally swans were discovered in Australia Avhich were not white ; and he asks what better warrant can uniformity of experience give us than it gave in this case. If after three thousand years a black swan turns up, must we not suppose it possible that in three thousand years more we may see a candle burn in an atmo- sphere of pure nitrogen ? In answering this query, let us begin by observing that in many cases, the mere accumulation of experiences is a matter of but little consequence. A child believes, after one expe- rience, that fire will burn. When the chemist has shown, by CH. III.] THE TEST OF TRUTH. 55 a single experiment, that nitrogen will not support combus- tion, we believe that it will be just the same through all future time. If we withhold our assent, " it is from a doubt whether the one experiment was properly made, not whether if properly made it would be conclusive." ^ Here, then, as Mr. Mill says, " is a general law of nature inferred without hesitation from a single instance ; a universal proposition from a singular one. Now mark another case, and contrast it with this. ISTot all the instances which have been observed since the beginning of the world, in support of the general pro- position that all crows are black, would be deemed a sufi&cient presumption of the truth of the proposition, to outweigh the testimony of one unexceptionable witness who should affirm that in some region of the earth not fully explored, he had caught and examined a crow, and had found it to be grey." What is the explanation of this difference ? " Why is a single instance in some cases sufficient for a complete induc- tion, while in others myriads of concurring instances, without a single exception known or presumed, go such a very little way towards establishing a universal proposition ? " The solution is to be sought in the extreme complexity of the conditions in the one case as contrasted with their extreme simplicity in the other. The scientific thinker does not con- sider blackness a necessary attribute of a crow, because he believes that some inappreciable variation in the nutrition of the bird, by altering the deposit of pigment in the feathers, might give us a grey or a white crow instead of a black one. Or if we do not reflect upon the matter so carefully as this, we at least regard a crow as a very complex aggregate of con- ditions and results, and find no difficulty in imagining that some of the conditions varying might affect the sum-total of results. Or if this also be taken to imply too much conscious philosophizing in us, it is undeniable that our conception of a crow, as of any other vertebrate, is made up of a large number ^ Mill, System of Logic, vol. i. p. 352. 56 COSMIC PHILOSOPHY. [i''^'- of conceptions, of which the conception of blackness is not the one upon which the specific identity of the snm-total depends. We have had experience of bay and of sorrel horses, of black and of white bears, of grey and of tortoise- shell cats; and, in accordance with such experience, we find it perfectly easy to regard any other animal as varying colour while retaining its specific identity. Our belief that all crows are black rests, therefore, upon purely negative evidence, — upon the absence of any experience of crows that are not black ; and no amount of negative evidence can out- weigh a single well-established item of positive evidence. Quite otherwise would it be if our explorer should assert that he had discovered crows destitute of a vertebrate skeleton. We should reply, with confidence, that in the absence of such a skeleton the animal in question could not have been a crow. And the justice of the reply becomes apparent when we turn to the case of the nitrogen, where the conditions are so simple that we can keep them all in mind at once, and where we can imagine no variation which shall not at once alter the whole character of the case. We cannot imagine nitrogen supporting combustion, for as soon as it did so it would cease to be nitrogen. That A is a, is an identical proposition only when the attributes of A are constant. Now the incapacity to support combustion is one of the attributes by the possession of which nitrogen is nitrogen. And to say that nitrogen may at some future time support combustion, is to say that A will cease to be A, and become something else. Now, why are we compelled to think thus ? Because we are incapable of transcending our exjxrience. Our experience of nitrogen is that it will not support combustion, and we are incapable of imagining it to be otherwise in contradic- tion to our experience. Our conception of nitrogen, formed by experience, is that of a .substance which will not support combustion, and we cannot mentally sever the substance CH. iii.J THE TEST OF TRUTH. 57 from its attribute without destroying the conception alto- gether. So we cannot conceive that a lump of iron will float in water. Why ? Because our conception of iron, formed solely by experience, is that of a substance which sinks in water ; and to imagine it otherwise is to suppress the conception, either of iron or of water, and to substitute some other conception in its place. We may try the experiment for ourselves. Try to imagine a lump of iron floating in water, and you will find that you cannot do it, without mentally endowing either the iron or the water with other attributes than those by virtue of which these substances are what they are, and thus your attempt destroys itself. Yet no Kantian would deny that your conception of iron or of water is wholly formed by experience. Your conception is just what experience has made it, and you cannot alter it without de- stroying it, simply because you cannot transcend experience. Here then we come to a conclusion quite the reverse of that maiutained by the Kantians. " The irresistible tendency we have to anticipate that the future course of events will resemble the past, is simply that we have experience only of the past, and as we cannot transcend our experience, we cannot conceive things really existing otherwise than as we have known them. The very fact of our being compelled to judge of the unknown by the known — of our irresistibly anticipating that the future course of events will resemble the past — of our incapacity to believe that the same effects should not follow from the same causes — this very fact is a triumphant proof of our having no ideas not acquired through experience. If we had a priori ideas, these, as independent of, and superior to, all experience, would enable us to judge the unknown according to some other standard than that of the known. But no other standard is possible for us." ^ The same general considerations will apply to the truths of mathematics, which some Kantians regard as the necessary ' Lewes, History of Philosophy, 2nd edition, p. 668. 58 COSMIC PHILOSOPHY. Irr. r. truths par excellence, — habitually speaking of them as if they were in some way truer than physical and chemical truths. Bearing in mind what was said a moment ago, it will be sufficient to observe that in mathematics we utter propositions with respect to certain particular relations alone, without regard to other conditions, and hence there is absolutely no room for contingency. Let me conclude this portion of the subject by a citation from Mr. Lewes :— "When we say that twice two is four, or that the internal angles of a triangle are equal to two right angles, we abstract the relations of ISTumber and Form from all other conditions whatever, and our propositions are true, whether the objects counted and measured be hot or cold, large or small, heavy or light, red or blue. Inasmuch as the truths express the abstract rela- tions only, no change in the other conditions can affect these relations ; and truths must always remain undisturbed until a change take place in their terms. Alter the number two, or the figure triangle, by an infinitesimal degree, and the truth is thereby altered. When we say that bodies expand by heat, the proposition is a concrete one, including the variable conditions ; but although these variable conditions prevent our saying that all bodies will under all conditions be always and for evermore expanded by heat, the case is not really distinguished from the former one, since both the Contingent and the Necessary Truth can only be altered by an alteration in the terms. If a body which does not expand by heat (there are such) be brought forward as impugning the truth of our proposition, we at once recognize that this body is under different conditions from those which our proposition included. This is the introduction of a new truth, not a falsification of the old. Our error, if we erred, was in too hastily assuming that all bodies were under the same condi- tions. Hence the correct definition of a Contingent Truth is ' one which generalizes the conditions ' ; while that of a Necessary Truth is ' one which is an unconditional generali- OH. iii.j THE TEST OF TRUTH. 59 zation.' The first affirms that whatever is seen to be true, under present conditions, will be true so long as these con- ditions remain unaltered. The second affirms that whatever is true now, being a truth irrespective of conditions, cannot suffer any change from interfering conditions, and must therefore be universally true."^ To this lucid exposition it is hardly necessary to add that the mental compulsion under which we accept mathematical truths is of precisely the same character as that under which we accept physical or chemical truths. Our conception of parallel lines — a conception which the Kantian admits to have been formed by experience — is a conception of lines which do not enclose space. And just as we found that, in order to imagine nitrogen supporting combustion, we were obliged to suppress the conception of nitrogen altogether and substitute for it some other conception, we also find that, in order to imagine two parallel lines enclosing a space, we must suppress the conception of parallel lines altogether, and substitute for it the conception of bent or converging lines. The two cases are exactly similar. In the one case, as in the other, our conceptions are but the registry of our ex- perience, and can therefore be altered only by being tempo- rarily annihilated. Our minds being that which intercourse with the environment — both their own intercourse and that of ancestral minds, as will be shown hereafter — has made them, it follows that our indestructible beliefs must be the registry of that intercourse, must be necessarily true, not because they are independent of experience, but because they are the only complete unqualified expression of it. Here then, on the ruins of the Kantian hypothesis, we may erect a canon of truth, as follows : — ' Histm-y of Philosophy, 4th edit. vol. i. p. cv. This view, which I hold to be the most important contribution ever made to the discussion of Necessity and Contingency, is still more thoroughly and forcibly presented by Mr. Lewes in his new work, Problems of Life and Mind, vol. i. pp. 390-414. 60 COSMIC PHILOSOPHY. [pt. i. A necessary truth is one that is expressed in a proposition of which the negation is inconceivable, after all disturbing conditions have been eliminated. A proposition of which the negation is inconceivable is necessarily true in relation to human intelligence. This test of inconceivability is the only ultimate test of truth which philosophy can accept as valid. Thus the uniformity-test of Hume and the inconceiv- ability-test of Kant are fused together in a deeper synthesis, — the deepest which philosophy can reach. As Mr. Spencer forcibly states it : " Conceding the entire truth of the position that, during any p)hase of human progress, the ability or inability to form a specific conception wholly depends on the experience men have had ; and that, by a widening of their experiences, they may by-and-bye be enabled to conceive things before inconceivable to them ; it may still be argued, that as at any time the best warrant men can have for a belief is the perfect agreement of all pre-existing experience in support of it, it follows that, at any time, the inconceiv- ableness of its negation is the deepest test any belief admits of Objective facts are ever impressing themselves upon us ; our experience is a register of these objective facts; and the' inconceivableness of a thing implies that it is wholly at variance with the register. Even were this all, it is not clear how, if every truth is primarily inductive, any better test of truth could exist. But it must be remembered, that whilst many of these facts impressing themselves upon us are occasional ; whilst others again are very general ; some are universal, and are unchanging. These universal and unchanging facts are, by the hypothesis, certain to establish beliefs of which the negations are inconceivable ; whilst the others are not certain to do this ; and if they do, subsequent facts will reverse their action." As this position has been vehemently attacked by Mr. Mill, who hardly admits for tlie test of inconceivableness any OH. III.] THE TEST OF TRUTH. 61 validity whatever, some further explanation is desirable. It must not be supposed that, in erecting such a canon of truth, we are imitating those high a priori metaj)hysieians, who regard all their cherished traditional notions as infallible in- tuitions, because of their professed inability to disbelieve them. This is a confusion of which Mr. Mill has not succeeded in keeping clear, and which has led him unintentionally to mis- represent the position taken by Mr. Spencer and Mr. Lewes. The confusion arises from the double sense of the word Idief} and the accompanying ambiguous use of the term inconceiv- able. By a singular freak of language we use the word belief to designate both the least persistent and the most persistent coherence among our states of consciousness, — to describe our state of mind with reference both to those propositions of the truth of which we are least certain, and to those of the truth of which we are most certain. We apply it to states of mind which have nothing in common, except that they cannot be justified by a chain of logical proofs. For example, you believe, perhaps, that all crows are black, but being unable to furnish absolutely convincing demonstration of the proposition, you say that you believe it, not that you know it. You also believe in your own personal existence, of which, however, you can furnish no logical demonstration, simply because it is an ultimate fact in your consciousness which underlies and precedes all demonstration. So with the axioms of geometry. If asked what are our grounds for believing that two straight lines cannot enclose a space, we can only reply that the counter-proposition is inconceivable ; that we cannot frame the conception of two straight lines enclosing a space ; that in any attempt to do so, the conception of straight lines disappears and is replaced by the conception of bent lines. We believe the axiom simply because we must believe it. ' The source of this confusion is the faihire to distinguish between the kind of belief which remains after " the reduction of inferences to sensa- tions," and that which is founded in a "reliance on unverified inferences."^ See Lewes, Problems of Life and Mind, vol. i. p. 369. 62 COSMIC PHILOSOPHY. [pt. i. It is only in this latter sense that the word belief is em- ployed in the canon of truth above stated, and when Mr. Spencer says that a given proposition is inconceivable, he means that it is one of which the subject and predicate can by no amount of effort be united in consciousness. Thus (to take Mr. Spencer's illustration), that a cannon-ball fired from England will reach America is a proposition which, though utterly incredible, is not inconceivable,— since it is quite possible to imagine the projectile power of cannons increased four-hundredfold, or one-thousandfold, were the requisite conditions at hand ; but that a certain triangle is round is an inconceivable proposition, for the conceptions of roundness and triangularity will destroy each other sooner than be united in consciousness. And manifestly we can have no deeper warrant for the truth of a proposition than that the counter-proposition is one which the mind is incom- petent to frame. Such a state of things implies that the entire intercourse of the mind with the environment is witness in favour of the proposition and against its negation. It is indeed a popular misconception, — a misconception which lies at the bottom of that manner of philosophizing which is called Empiricism, — that nothing can be known to be true which cannot be demonstrated. To be convinced that this is a misconception, we need but to recollect what a demonstra- tion is. Every demonstration consists, in the first place, of a series of steps in each of which the group of relations expressed in a proposition is included in some other and wider group of relations, — is seen to be like some other group previously constituted. Now if this process of inclusion is not to be carried on for ever, we must come at last to some widest group, — to some generalization which cannot be included in any wider generalization, and of which we can only say that the truth which it expresses is so completely abstracted from perturbing conditions that it can be recognized by a simple act of consciousness as self-evident. If, for example, " we CH. lu.] THE TEST OP TRUTH. 63 ascribe the flow of a river to the same force which causes the fall of a stone," and if, " in further explanation of a move- ment produced by gravitation in a direction almost horizontal, we cite the law that fluids subject to mechanical forces exert reactive forces which are eq^ial in all directions," we are going through a process of demonstration, — we are including a special fact under a more general fact. If now we seek the warrant for this more general fact, and find it in that most general fact that force persists, we are still going through a process of demonstration. But if lastly we inquire for the warrant of this most general fact, we shall get no reply save that no alternative can be framed in thought. That force persists we are compelled to believe, since the proposition that force can arise out of nothing or can lapse into nothing is a verbal proposition which we can by no amount of effort translate into thought. Thus at the end of every demonstra- tion we must reach an axiom for the truth of which our only test is the inconceivability of its negation. Secondly, from a different point of view, a demonstration is a series of propositions, every one of which is necessarily involved in the preceding one. How do we know it to be thus necessarily involved ? How do we know that the state- ment that action and reaction are equal and opposite is necessarily involved in the statement that force persists ? Simply because we can conceive no alternative, since to do so would be to perform the impossible task of formulating in consciousness an equation between something and nothing. Thus our only warrant for each step of a demonstration is the fact that any alternative step is one which the mind cannot take. Such is indeed our only warrant for that most certain of all facts — the existence of our own states of consciousness. If you say that you have a sensation of redness, and I require you to prove the statement, you can only reiterate that such is the fact, the testimony of consciousness as to the 64 COSMIC PHILOSOPHY. [pt- i- existence of its own states being final, and admitting of no appeal. You cannot conceive it to be otherwise. During the presence of the sensation of redness it is impossible for any opposite state of consciousness, such as the sensation of blueness, to emerge. With regard to the cause of the sensa- tion, the case is wholly different. The sensation of redness may be due to the presence of an external object from which emitted red rays impinge upon the retina ; or it may be due to the presence of certain foreign substances in your blood which excite in the optic nerve such a rate of undulation as to produce the consciousness of red colour. All this is matter of inference, and must be verified by the repeated application of the test of truth. But for the ultimate dictum — that the given state of consciousness exists — you have the direct warrant of consciousness itself In the light of this explanation, does not our canon of inconceivability seem almost a truism, and does it not seem a singular ignoratio elenchi when Mr. Mill urges against us that the ancients could not conceive the existence of the antipodes, which nevertheless exist? It is quite true that the ancients could not helieve that men could stand on the other side of the earth without falling off ; and this was because they falsified one of the conditions of the complex case. They imagined gravity continually acting downwards, not knowing that downwards means toward the centre of the earth. What they could not conceive was that an unsupported body will not fall ; and this is still strictly inconceivable, since to assert that an unsupported body will not fall is to assert that a given amount of gravitative force, when not counteracted by an equivalent opposing force, will not mani- fest itself in motion, — a verbal assertion which can by no effort be construed into thought. A similar reply awaits Mr. Mill's argument from the old belief in the destructibility of matter. It is now incon- ceivable that a particle of matter should either come into CH. HI.] THE TEST OF TRUTH. fi5 existence or lapse into non-existence. But before the use of the balance in chemistry had shown experimentally that nothing ever disappears, hypotheses were freely propounded in which the indestructibility of matter was entirely ignored ; and, accordingly, Mr. Mill appears to believe that in former times the annihilation of matter was thinkable. In reply it is enough to observe that, so long as human intelligence has been human intelligence, it can never have been possible to frame in thought an equation between something and nothing : yet this is the impossibility which must be surmounted before the annihilation or the creation of a particle of matter can become representable in consciousness. The truth is that whoever, before the discoveries of chemistry, maintained that matter is destructible, defended a verbal proposition, which answered to no framed or frameable conception. Of a piece with this is the fact that in all ages men have tortured, slain, calumniated, or otherwise persecuted each other in their zeal to get sundry propositions established, the subject and predicate of which could never be united in thought. It is not so very long since Michael Servetus wa,s burned at the stal^e for a heresy partly based upon doubts as to the possible equality or identity of three and one ; yet not even Mr. Mill would maintain that it has ever been possible for human intelligence to join together the members of the quantitative theorem implied in the doctrine of the Trinity. It appears, therefore, that men may believe, or at least maintain, what they can in nowise conceive. As Mr. Spencer well says, " Eefrain from rendering your terms into ideas, and you may reach any conclusion whatever. That the whole is equal to its part is a proposition that may be quite comfortably entertained so long as neither wholes nor parts are imagined." This is one of the ways in which so many absurd theories obtain currency, and having once become current are so difificult to banish from circulation. The philologist A. W. Schlegel once suggested that the terminations of words may VOL. I. F 66 COSMIC PHILOSOPHY. [pt. have grown out from the roots, just as branches of trees grow from axillary buds. Inductive philology has proved this notion to be false, and has shown that in all cases a termination is the abraded relic of an originally distinct qualifying word, which by constant use and through rapid pronunciation, during primitive ages when words were ad- dressed only to the ear, has become inseparably agglutinated to the qualified word or root. This discovery, which has long been completely verified, of course supersedes and renders antiquated the hypothesis of Schlegel. But the point which here concerns us is that no such elaborate induction was needed to show that the notion of a budding termination is in itself absurd. All that was needed to reveal its absurdity was to stop and translate the words used into ideas. To say that a termination buds out from a root, is to combine words which severally possess a meaning into a phrase which has no meaning. We can severally form concepts of a word- termination, of a word-root, and of the process of budding; but the three concepts are wholly disparate and refuse to unite into a thinkable proposition. The hypothesis had no other foundation than the vague associations with the processes of vegetal life which cluster about such a word as " root " ; and the fact that a scholar like Schlegel could seriously found a theory of language upon such a mere chaos of half-shaped conceptions shows us how easy it is for highly-educated men to think in a very slovenly manner. But it likewise con- clusively shows us that the assent of philosophers in past ages, or of uneducated people in our own age, to sundry unthinkable propositions, is not to be cited as evidence that there are minds which can think what is unthinkable. The building up of enormous theories out of purely verbal propositions, which do not correspond to any thinkable con- catenation of conceptions, has always been the besetting sin of human philosophizing. It has been known, since the Middle Ages, by the apparently incongruous epithet of H. in.] THE TEST OF TRUTH. 67 Eealism, because at that time it was most conspicuously illustrated in the famous theory that wherever there is a general term there must be a real objective thing correspond- ing to it, — a general Horse, for example, in addition to all individual horses. This single phase of the mental habit in question might be cited as an all-sufficient answer to Mr. Mill's objection. Mr. Mill would be the last to admit that the realists were able to conceive of Horse except as some particular horse ; yet they stoutly maintained that they could and did frame such a conception. The Platonic theory of Ideas was based upon this realistic tendency to lend an objective value to the mere verbal signs of subjective con- ceptions, which was dominant in the philosophy of the Greeks and of the scholastics, and which, in modern times, is well exemplified in the philosophy of Hegel. We thus see that men may believe — or believe that they believe — propositions which they cannot, in the strict sense of the word, conceive. Until men have become quite freed from the inveterate habit of using words without stopping to render them into ideas, they may doubtless go on asserting propositions which conflict with experience ; but it is none the less true that valid conceptions wholly at variance with the subjective register of experience can at no time be framed. And it is for this reason that we cannot frame a conception of nitrogen which will support combustion, or of a solid lump of iron Which will float in water, or of a triangle which is round, or of a space enclosed by two straight lines. So that when Mr. Mill hints that it was once possible for men to frame conceptions which cannot now be framed, he tacitly assumes that conceptions may have been framed of which the elements have never been joined together in experience. Yet of all possible psychological theorems there is none, I suppose, which, when overtly stated, Mr. Mill would more emphatically deny than this. To see Mr. Mill unwittingly arrayed in the lists against the experience-theory is indeed a singular spec- F 2 68 COSMIC PBILOSOPHY. [pt. i. tacle ; but it is only one instance, out of many, of the way in wliich that theory has suffered from its association with empiricism. When in a future chapter we come to treat of the evolution of intelligence, we shall see that Mr. Spencer was the first to penetrate to the very core of the experience- philosophy when he perceived that the deepest warrant for the perfect conformity of a given proposition with experience is the unthinkableness of the counter-proposition.^ But now, what do we mean when we say that, after eliminating all perturbing conditions, a proposition of which the negation is unthinkable must be necessarily true ? By a confusion of ideas very unusual with him, Mr. Mill seems to think that we mean to accredit such propositions with express- ing some necessary relation among objective realities per se, apart from their relation to our intelligence : for he somewhere charges Mr. Spencer with " erecting the incurable limitations of the human conceptive faculty into laws of the outward universe." When correctly interpreted, however, Mr. Spencer will be found to have done no such thing. He simply erects them, as Mr. Lewes expresses it, into " laws of the concep- tions we form of the universe." Holding as we do, that all our knowledge is derived from experience, that we have no experience of the objective order of the relations among things, and hence can never know whether it agrees or disagrees with '*&'■ 1 Since my final revision of this chapter, T find the case thiis admirably put into a nut-shell by Mr. Lewes, in his now forthcoming worlc, Problems of Life and Mind, vol. i. p. 396 : — "The arguments which support the d priori view have been ingeniously thrown into this syllogism by Mr. Killick : The necessary truth of a proposition Is a mark of its not being derived from ,Ex- perience. (Experience cannot inform us of what must be ;) The inconceiv- ability of the contradictory is the mark of the necessary truth of a proposi- tion : Therefore the inconceivability of its contradictory is a mark of a pro2m- sition not being derived from Experience. — This syllogism is perfect in form, but has a radical defect in its terms. Tlie inconceivability of a contradictory results from the entire absence of experiences on which a contradiction could be grounded. If there were any trutUs independent of Experience, contra- dictions to them would be conceivable, since there w■ Lewes, History of Philosophy, 3rd edit. vol. ii. p. 522. 126 COSMIC PHILOSOPHY. [pt. i. aside philosophy, but place it on a firmer foundation than before. And while it is thus apparent that we have not identified metaphysics with philosophy, it is also evident that we have by no means fallen into the vulgar error of identi- fying it with psychology, or the inquiry into the phenomena of consciousness, which is as much a science as chemistry or physiology. How, then, shall we precisely define the meta^ physics against which we have, during these five chapters and from various points of attack, been waging war ? To arrive at the true meaning of " Metaphysics," we can hardly do better than go back to the historical origin of the word. Aristotle wrote a treatise on Physics, and also an elaborate dissertation upon sundry transcendental topics, which being placed immediately after the other in his collected works, received the title of ra fiera ra (pvcriKa, or " Things- which-come-after-the- Physics." It was in this way that the term came into use ; and it needs but little playing with the elastic significance of the preposition, to arrive at a thoroughly just idea of the meaning of the expression. Meta- physics, thus considered, means a set of inquiries which lie beyond the bounds of Physics. Physics,— in the widest sense tions of word, — dealing solely with phenomena in their lela- of the coexistence and succession, metaphysics deals with something lying beyond the phenomena A physical explana- tion is content with analyzing phenomena as it finds them ; a metaphysical explanation is not content until it has added something not given in the phenomena. Metaphysics, there- fore, is not confined to psychology, but may deal with any subject, and has in fact obtruded its explanations upon most subjects. When mercury was seen to rise in a tube, in appa- rent contradiction to the general phenomena of gravity, meta- physics said that it was because "Nature abhorred a vacuum." Physics, without going beyond the facts given in the case, explained it by a reference to the pressure of the atmosphere upon the mercury without the tube. So the phenomena of CH. v.] THE TWO METHODS. 127 causation were metaphysically explained by the supposition of a specific hidden power in the cause, which constrains the effect to follow. Hume denied the existence of any such specific hidden power, and his denial was also metaphysical, because neither the presence nor the absence of such a specific power is a necessary inference from the phenomena. If we would keep clear of metaphysics, we must in such a case neither affirm nor deny concerning a subject which lies utterly beyond our reach. Physics knows nothing of causa- tion except that it is the invariable and unconditional sequence of one event upon another: whether the one event, in a metaphysical sense, constrains the other to follow it or not we cannot tell. Physics knows nothing of such constraint — neither that it exists, nor that it does not exist. For the moment I have, somewhat too freely, used the word "physics " as synonymous with " science " ; for I have aimed at bringing out the fundamental distinction between metaphysics and science, — which is this : — A scientific ex- planation is a hypothesis which admits of verification, — it can he either proved or disproved; while a metaphysical explanation is a hypothesis which docs not adndt of verification, — it can neither be proved nor disproved. Newton's hypothesis of gravitation, to account for the planetary motions, was strictly scientific ; and so was Descartes' hypothesis of vortices, to account for the same phenomena. The former admitted of proof, and the latter admitted of disproof. But Stahl's hypothesis of a Vital Principle, to account for the phenomena of life, was strictly metaphysical. Whether it is true or not, we can never know. Push our researches as far as we may, we can know life only as the assemblage of certain phenomena, displaying the activity of certain forces. Whether in addition to this there- is a Vital Principle or not, no amount of research can ever tell us. Sciencfe has simply nothing to do with it. Thus we see that the fundamental difference between metaphysics and science is the difference between the 128 COSMIC PHILOSOPHY. [pt. i. subjective and the objective methods. That the difference in method is more fundamental than the difference in the character of the objects which are studied, is shown by the fact that " a theory may be transferred from metaphysics to science, or from science to metaphysics, simply by the addition or the withdrawal of its verifiable element." Thus, as Mr. Lewes observes, "the law of universal attraction becomes pure metaphysics if we withdraw from it the verifiable specification of its mode of operation. Withdraw the formula, ' inversely as the square of the distance and directly as the mass,' and Attraction is left standing — a mere ' occult quality.' Indeed the Cartesians reproached it with being such an occult quality, and stigmatized it as a revival of Aristotelianism. On the other hand, add this verifiable formula to the 'inherent virtue ' of the old metaphysicists, and the result is a strictly scientific proposition." ^ Here also is revealed the inherent weakness of meta- physics : it is incapable . of making discoveries. For veri- fication is absolutely essential to discovery. No theorem can be accepted as a discovery until it has been verified, and the theorems of metaphysics do not admit of verification. Hence the utter barrenness of the metaphysical method. From Thales downwards — according to the current reproach ■ — philosophers have been disputing over the first principles of their subject, and are now no nearer to a solution than when they began to dispute. It is not, however, as is some- times superficially supposed, because metaphysicians disagree, that their method must be rejected by any philosophy which would found itself upon science ; but it is because their disagreement can never end in agreement, — can never lead to knowledge. Since there will always be room for difference of opinion on many subjects, until the human mind shall have explained and classified all the phenomena of nature, it cannot be demanded of any system of philosophy that it ' Lewes, Aristotle, p. 84. CH. v.] TEE TWO METHODS. 129 shall admit only such couclusions as are not open to con- troversy. Such a requirement would virtually prohibit philosophy altogether. The difference between a scientific and a metaphysical theorem is not that the former is not open to controversy, but that it admits of verification ; it can, either now or at some future time, be proved to be either true or false. All such theorems may be admitted by a scientific philosophy. Until they have been verified, we may take account of them provisionally, as legitimate hypo- theses : after they have been put to a crucial test, we may either incorporate them with our philosophy or definitely abandon them. Our philosophy, therefore, like all the sciences whence it obtains the general truths which it seeks to organize into a body of universal truth, may admit any number of subjects of dispute ; but it can admit no question as a fit subject of dispute, which, from the nature of the case, can never be settled. It is perfectly in keeping, for example, for two upholders of the Doctrine of Evolution, as well as for two scientific specialists committed to no general doctrine, to hold opposite views concerning the hypothesis of sponta- neous generation. Since this is strictly a scientific hypothesis, dealing solely with phenomena, and invoking no unknowable agencies; and since there is no reason, in the nature of things, why it should not sooner or later be established or overthrown by some crucial experiment ; there is nothing anomalous in the fact of two such thoroughly scientific evolutionists as Prof. Huxley and Dr. Bastian holding opposite opinions as to its merits. But it would not be in keeping for two scientific philosophers to wrangle over Leibnitz's doctrine of Pre-established Harmony, because that is a hypothesis which can never be proved or disproved. The data necessary for its verification do not exist, and therefore no system of philosophy, which would keep clear of metaphysics, can recognize it as a legitimate subject for investigation. Again, in the eighteenth century there were VOL. I. K 130 COSMIC PHILOSOPHY. [ft. i. two rival theories of light. According to the theory of Newton, a ray of light is a linear series of material cor- puscles, darted from the luminous object. According to the theory of Huyghens, a ray of light is a system of molecular undulations which move outward in ever-increasing con- centric shells whose normals are radial, and which are set in motion by undulations among the molecules of the lumi- nous object. At the beginning of the present century the corpuscular theory was submitted to a set of crucial investiga- tions which overthrew it; and more recently the undulatory theory has been submitted to a course of crucial investigation which has finally established it. Both these theories were scientific in conception, and previous to the researches of Young and Fresnel a scientific philosopher might have con- sistently espoused either. Such are the controversies of science, which sooner or later have always led, and will always lead, to agreement and to knowledge. Far different is it with the disputes, of metaphysics, which — conducted upon the subjective method, and dealing with unverifiable hypotheses — have never led, and can never lead, to anything but an endless renewal of dispute, in scecula sceculorum. In this condemnation of the subjective method, the Cosmic Philosophy here expounded is entirely in harmony with the Positive Philosophy, as set forth in Comte's "first great work, and as held by M. Littr4 and Mr. Mill. Indeed there is probably nothing in the present chapter which might not be cited by the Positivist in confirmation of his opinions as to the limits of philosophical inquiry. The Positive Philosophy is based upon the assertion of the relativity of all knowledge ; and, however fatally inadequate may have been its psycholo- gical interpretation of that doctrine, there is no ground for accusing it — as represented by Mr. Mill and M. Littre — of inconsistency in its adherence to the scientific method for which the doctrine of relativity supplies the justification. Since Bacon's time there have been few thinkers who have OH. v.j THE TWO METHODS. ui insisted more strenuously than Comte upon the necessity of distinguishing between legitimate and illegitimate hypotheses, or who have more clearly prescribed the conditions under which alone can any given hypothesis be regarded as legiti- mate. Unfortunately, by a strange and ironical fate, the writer who contributed so much toward the establishment of sound methods of philosophizing, lived to become a proficient in the subjective method, a pitiless scorner of crucial experi- ments, and a weaver of vagaries which might well be matched with those above cited from Plato and Hegel. The historical importance of this phenomenon is great enough to justify us in treating it at some length. Though in Comte's earlier works a somewhat obtuse sense of the requirements of verification is now and then to be noticed ; and though there is a tendency, which visibly in- creases toward the end of the " Philosophic Positive," to sub- stitute intensely dogmatic ex cathedrd dicta in the place of arguments ; yet the necessity for strict obedience to the objective method is nowhere explicitly denied. It is in- sisted, with entire justice, that every hypothesis which does not adndt of verification should be remorselessly discarded from philosophy; and that even a verifiable hypothesis should never be incorporated as a part of philosophy or science until it has been actually verified. Par different is the attitude taken by Gomte in his later works, when he is attempting to reconstruct society. In the " Politique Posi- tive " he begins by endeavouring to reinstate the subjective method ; deluding himself, by a play upon words, into the belief that that method can be so reformed as to become available in the search for positive truths. " The subjective method," he tells us, "possesses striking advantages which can alone compensate for the inconveniences of the objective method." This unhappy sentence is of itself enough to show how far the writer had strayed from positive grounds. Here we see the necessity for constant verification characterized K 2 132 COSMIC PHILOSOPHY. [pt. r. as an " inconvenience," and the liberty to string together pre- mises and conclusions without ever stopping to test their conformity to facts is called a " striking advantage." Nothing could be more thoroughly metaphysical in temper. The " in- convenience " of the objective method is the inconvenience of being often obliged to stop and confess our ignorance of many things we should Uke to know, our lack of many data we should be glad to possess. The " striking advantage " of the subjective method is no other than the advantage en- joyed by the metaphysician of being permitted to persuade himself that he has arrived at complete knowledge because he has never stopped to confront the order of his conceptions with the order of phenomena. But let us continue with Comte : " Our logical system can be rendered complete and durable only by the intimate union of the two methods. His- tory does not authorize us to regard them as radically irre- concilable, provided that both are systematically regenerated in accordance with their common function, intellectual and social. To yield to theology the exclusive privilege of using the subjective method is as unnecessary as to see in theology the only legitimate basis of religious feeling. If sociology may possess the latter, it may also possess the former, as the two are intimately connected. To this end it is enough that the subjective method, renouncing the vain search into effi- cient and final causes, should henceforth, like the objective method, be employed solely in the discovery of natural laws, whereby our social condition may be ameliorated." ^ I do not know where one could find a passage, in the literature of modern philosophy, more lamentably confused in its ideas than this. The subjective method says that verification is not necessary ; the objective method says that verification is necessary ; and yet we are told that the two are not " radically irreconcilable ! " It is proposed to " regenerate " the subjective method : yet there is no way of ' Politique Positive, torn. i. p. 455. CH. v.] THE TWO METHODS. 133 regenerating it save by forcing it to verify its premises and conclusions ; and when this is done, it ceases to be the sub- jective and becomes the objective method. But Comte thinks this is not necessary; the subjective method may be used provided it be employed only upon scientific questions, only in ascertaining the laws of phenomena. That is to say, as long as you confine yourself to scientific questions, and leave theology and metaphysics alone, you may imagine some plausible hypothesis and then reason away until you have worked out a whole theory of natural phenomena, never stopping to observe or experiment, but dogmatically pro- claiming your conclusions as infallible because they seem to flow logically from the premises! Can it be that we are here listening to the man who spent one half of his life in investigating the history of science, — the man whose labours did so much toward renovating inductive logic ? The whole history of science proclaims the utter absurdity of the posi- tion taken by Comte. The subjective method has been em- ployed, from the earliest times, upon purely scientific ques- tions which took no note of causes, efficient or final ; and its eternal impotence is illustrated upon every page of the annals of scientific error. In molar physics, it led to the doctrine that all motion is naturally circulg,r ; in astronomy it per- suaded men that the sun and planets move in circular orbits about the central earth; in chemistry it instigated many generations of experimenters to the fruitless effort to convert lead or iron into gold ; in physiology it suggested the notion that the arteries are air-vessels, and caused that notion to be held for centuries ; in pathology it sanctioned the fal- lacy that fever is an unnatural exaltation of the powers of the organism, — a fallacy which has sacrificed many a valuable life to the lancet ; in political economy it favoured the de- lusion, born of selfish instincts, that the commercial interests of each community are antagonistic to those of the communi- ties with which it trades, — a delusion which is responsible 134 COSMIC PHILOSOPHY. [pt. i. for much foolish warfare, and which underlies the whole iniquitous system of so-called " protective " tariffs by which so many countries are even yet impoverished. Verily this illegitimate deduction, which verifies neither premise nor conclusion, but relies wholly on subjective coherence, has been tried quite long enough by the test which Comte recommends for it. Just so far as men have verified their hypotheses, either by direct observation, or by deduction based on observation, have they extended the boundaries of knowledge. Just so far as they have neglected such verifica- tion, have they gone astray amid the countless vagaries which have ever loved to encumber the path of scientific inquiry. To admit that we do not know what we have not verified requires rare self-denial, no doubt; a self-denial to which nothing, save the patient habit of scientific inquiry, can fully accustom us. This is the " inconvenience " of which Comte speaks, as attaching to the objective method. But mankind are fast reaching philosophic maturity ; and we are already getting too thoroughly used to the requirements of science to be much longer content with the childish device of play- ing that whatever is in our ideas is in the facts. Whatever may be our failings in practice, we have become nearly unanimous in the declaration that before any hypothesis can be accepted it must be verified. Strange that in the latter half of the nineteenth century these criticisms should still need to be made ! Stranger still that they should be called forth by the writings of the great successor of Bacon and organizer of positive philosophy ! Strangest of all that able men should still be found so imbued with the spirit of discipleship as to resort to all manner of logical subterfuges in order to destroy their force ! Yet to show that I have by no means exaggerated the perversity of Comte's position, let me cite a page from Mr. Mill. " Among all the aberrations of scientific men, Comte thinks none greater than the pedantic anxiety they show c«. v.] THE TWO METHODS. 135 for complete proof, and perfect rationalization of scientific processes. It ought to be enough that the doctrines afford an explanation of phenomena, consistent with itself and with known facts, and that the processes are justified by their fruits. This over-anxiety for proof, he complains, is breaking down by vain scruples the knowledge which seemed to have been obtained ; witness the present state of chemistry [in 1854]. The demand of proof for what has been accepted by Humanity .... is a revolt against the traditions of the human race. So early had the new High Priest adopted the feelings and taken up the inheritance of the old." Mr. Mill goes on to remark upon the new sense in which he began to employ his famous aphorism that " the empire of the dead over the living continually increases.'' " As is not uncom- mon with him, he introduces the dictum in one sense and uses it in another. What he at first means by it is, that as civilization advances, the sum of our possessions, physical and intellectual, is due in a decreasing proportion to ourselves, and in an increasing one to our progenitors. The use he makes of it is, that we should submit ourselves more and more implicitly to the authority of previous generations, and suffer ourselves less and less to doubt their judgment, or test by our own reason the grounds of their opinions. The unwillingness of the human intellect and conscience, in their present state of ' anarchy,' to sign their own abdi- cation, he calls ' the insurrection of the living against the dead.' To this complexion has positive philosophy come at last ! "1 To realize the completeness of the break between Comte's earlier and later speculations, we have only to remember that the deepest of all the distinctions which he sought to establish between positive philosophy on the one hand and metaphysics and theology on the other, is the ineffaceable distinction of method : the one insists upon objective 1 Mill, Auguste Comte and Positivism, p. 162. 136 COSMIC PHILOSOPHY. [pt. i verification, while the others are content with subjective congruity. Yet here we see Comte explicitly and with vehement dogmatism repudiating observation and experiment, and maintaining, as unreservedly as Hegel, that so long as our conceptions are systematic and mutually harmonious, it makes no difference whether they are verified or not ! It would be an interesting study to trace in detail the circumstances concerned in bringing about this singular aberration of a great scientific intellect. For while the proclamation of the subjective method, and its more or less consistent employment, by Descartes and Hegel, was logically based upon their erroneous psychological theories concerning the sources of knowledge ; on the other hand, this metamor- phosis in the opinions of Comte had no logical justification whatever, but was determined by circumstances of a purely personal character. It was due partly to what I may call the impatience of constructiveness, — the imperious mental demand for the erection of a system at whatever cost, — and partly upon the exaggerated over-estimate of self which is a symptom of incipient monomania. In his youth Comte was an insatiable reader, and before he began the work of constructing the Positive Philosophy he had amassed vast stores of learning in almost every department of knowledge. There is no good reason for doubting that in 1830, when the publication of his great work began, he was, with a few serious exceptions, fully abreast of the best science of the times. But in the course of the twelve years during which the composition of this work went on, he found it desirable to alter his habits of study. Finding that constant attention to the progress of events interrupted the consecutive development of his thoughts, he began to abstain from all reading whatever, save in a few of his favourite poets. Still later in life he erected this practice into a general principle of action, and as a matter of conscience refused to take any note of the pro- CH. v.] THE TWO METHODS. 137 ceedings going on about him in the intellectual world. He utterly neglected not only newspapers, but also contemporary works on science, and even scientific periodicals, and devoted himself almost exclusively to music and to sesthetic or devotional literature, such as Homer, Dante, Thomas a Kempis, St. Augustine and Bossuet, Moliere, Fielding and Lesage. This holding aloof from the course of contemporary specula- tion, he called " cerebral hygiene." It should rather be regarded as a source of mental one-sidedness than as a source of mental health. I have no intention of depreciating the vast amount of invaluable food for thought which is to be obtained from the study of such books as those just named. Without studying Homer and Dante and Moliere and the rest, one can get but a very meagre notion of human history as concretely revealed in the thoughts of past generations. Nor can it be denied that there was much that was truly sensible in Comte's plan of leaving off study when about to write. The successful expositor of a system of thought is not the man who is always cramming, and who perhaps keeps but a few weeks in advance of the particular theme which he is expounding. It is the man who by long years of patient thinking has completely mastered the system, and has it so thoroughly elaborated in his mind that he can sit down and write it out of the fulness of his knowledge, without needing to look at books. And in such cases it is no doubt desirable to shut oneself up and allow nothing to distract the mind until the work is accomplished. So far, Comte was doubtless wise in doing as he did. But beyond this point, there is no wisdom in keeping aloof from contemporary matters. As soon as writing is done, reading should begin again ; every conclusion should be carefully verified, and every statement revised in the light of the newest science. Otherwise room is left for the subjective method to enter, and opportunity is given the mind to tickle itself with the belief that it has reached finality on some points. There is no safety for the 138 COSMIC PHILOSOPHY. [pt. i. thinker who isolates himself, year after year, from the work which his contemporaries are doing. Such a proceeding, as Comte's experience is enongh to show, is fraught with grave dangers, both intellectual and moral. The intellectual danger is that the thinker will be left hopelessly in the rear of the scientific movement of the age ; will lose, from lack of the requisite stimulus supplied by open criticism and argument, the habit of bringing all his conclusions to the test of verifica- tion ; and will thus gradually fall into the habit of reasoning upon his plausible hypotheses as if they were established. The moral danger is that which menaces all isolation, social or intellectual, — the danger of excessive egoism, of over- confidence in one's own conclusions, and undue respect for one's own achievements. It is well enough for a writer to be dogmatic, provided his dogmatism is sustained by vigorous argument. But the writer is past all hope who habitually thinks to make loud assertion do the duty of argument ; and this is a habit into which every one is more or less liable to fall who is not constantly coming in contact with other thinkers, and forced continually to defend his conclusions by the objective appeal to univers- ally admitted principles. I believe these considerations will go far toward accounting for the unfortunate position taken by Comte toward the close of his life. Always of a warm and enthusiastic tempera- ment, self-confident to an inordinate degree, and vain with more than a Frenchman's vanity, during his long period of isolation these traits and tendencies were unduly strengthened. The consciousness — to a certain extent well founded — of the grandeur of the task which he had accomplished, grew iipon him apace ; and not taking note of the serious defects and omissions which advancing science was constantly disclosing in that work, he became more and more settled in the con- viction that it was final, so far as it had gone. Measuring all his newly-framed hypotheses solely by their congruity CH. V.J TjSM two methods. 139 with the general system of his conceptions, he gradually lost the scientific habit. He ceased to take into account the fact that what, seemed a necessary inference to him would not necessarily seem so to minds differently moulded, unless sustained by the requisite proofs. Thus he emerged from the scientific into a pontifical state of mind, in which, just as •with Plato in his old age, it was enough that an opinion seemed true to him for him straightway to proclaim it as binding on all men.' Moreover it is not improbable that his too exclusive intercourse with the devotional writers of the Middle Ages had much influence in generating that mystical tone which characterizes all his later writings. The " Imita- tion of Christ " is a noble work, which has been a comfort to many generations ; but it is hardly a suitable book with which to nourish one's habits of scientific thought. By long contemplation of the many admirable features of mediaeval civilization — features to which no previous writer had done such unstinted justice — Comte came at last to forget his relative point of view, and in his horror of revolutionary anarchy he began to imagine that certain points of medi- ' In its initial scientific attitude and in its final grotesque vagaries, the career of Plato's mind may be instructively compared with that of Comte's. In his earlier dialogues Plato professes to be, like Sokrates, a mere investi- gator of the methods by which trustworthy knowledge is obtained ; just as Comte, in his first great work, is simply a co-ordinator of scientific methods and doctrines. In the Parmenides and Theaitetos, indeed, we may find, as strikingly presented as in any modern treatise, the antinomies or alternative impossibilities which, like the lions before Palace Beautiful, confront the pil- grim on either hand whenever he seeks to cross the barrier which divides the realm of science from that of metaphysics. But at a later period we find Plato, like Comte, renouncing the scientific attitude, and setting himself up as the founder of an ideal Commimity, in which the pervading tendencies which have shaped actual societies were to be ignored or overridden, and in which existence was to be made intolerable to all persons not built after the Platonic pattern. And finally we have seen Plato, in the Timaios, working out a system of the universe in accordance witli his own subjective concep- tions, and making a very sorry piece of work of it when -compared with con- temporary science as displayed in the writings of Hippokrates and Aristotle ; just as Comte, in his latest years, began to write a ' ' Subjective Synthesis " in which scientific truths are fearfully and wonderfully travestied. Historic parallelisms are often very misleading ; but the parallel here indicated is one which I believe the most sedulous exanynation will justify. 140 COSMIC PHILOSOPHY. [vt. i. tevalism might be again revived and engrafted upon our modern life. Thus by degrees he framed the conception of a sort of ISTeo-Catholicism, with power as unlimited and ceremonies as complicated as the old one, but with the science of 1830 substituted for evangelical theology, and with Comte installed as sovereign Pontiff. As a natural result of this new position, his self-confidence grew until it became even too great to be ludicrous. Literary history affords us no other example approaching to it, unless, as Mr. Mill suggests, in the case here and there of some " entirely self-taught thinker who has no high standard with- which to compare himself." He habitually alludes to himself as the peer of Aristotle and St. Paul combined ; or as the only really great philosopher, save Descartes and Leibnitz, who has been seen in modern times. When in a future chapter we come to examine the system of polity which awakened in Comte such transcendent self- commendation, we shall find, as might be expected from the subjective method pursued, but little that is of value to reward our search ; although there are detached speculations of great interest, serving to remind us that we are dealing with a mighty though fallen thinker, and not with an un- disciplined pretender. For the purpose of the present chapter it will be enough to note some of his latest philosophic vagaries, in which, pushing the subjective method to the limits of self-refuting absurdity, he maintained that all science should be remodelled in conformity to the require- ments of the imagination. Missing links in the geological series of plants and animals should be supplied by fictitious " constructions of the reason," so that our craving for symmetry may be appeased. Above all, science must be as far as possible deprived of its " dryness," and vivified by "sentiment." To this end it is well to accustom ourselves to the belief that all nature is alive, and that inorganic bodies, for instance, exert volition and feel what is done to OH. v.] THE TWO METHODS. 141 them ! Fetishism is, in express terms, restored, and we are invited to adore the Earth as the Grand Fetiche. This great fetish is supposed to have planned a shrewd system of shocks or explosions, by which to render its orbit less eccentric and the inclination of its axis better fitted for the requirements of the Grand Eire, the Human Eace. But even this is not enough to |satisfy the demands of " le cceur." We must adore whatever is useful to Humanity, and therefore must erect Space into a deity, and endow it with feeling, though not with intelligence. Not only physics but mathematics also must be made religious. And thus we reach the Comtist \ Trinity, — Humanity, the Grand Being; Earth, the Grand .; Fetish ; and Space, the Grand Medium ! ! ! Decimal numera- \ tion is to be abandoned in favour of a septimal system ; because seven is a sacred number, and moreover a prime number, incapable of division, and therefore well adapted to impress us with a due sense of the weakness of the human mind and the limitations of thought ! This is the wonderful philosophy which is thought worthy to take the place of the vain inquiries which scientific men still obstinately persist in making, into the motions of the stars, the undulations of atoms, and the development of organic life upon the globe ! Thus we might go on citing page after page of the most extravagant vagaries ever conceived outside of Bedlam ; or, remembering the many valuable services for which mankind must ever be grateful to Comte, we might less harshly, and not less truly, call them the most mournful exhibition furnished by the annals of philosophy, of a great mind utterly shattered and ruined. Mr. Lewes rejects somewhat vehemently the suggestion of M. Littr^, that these wild fancies are evidence of actual insanity.^ For my own part, I do not see what there is unsound or uncharitable in M. Littr^'s suggestion. The only healthful activity of the mind is an ^ History of Philosophy, 3rd edit. vol. ii. p: 583. 142 COSMIC PHILOSOPHY. [pt. i. objective activity, in which there is as little brooding over self as possible. The less we think of ourselves, and the more we think of our work, the better. Dwelling on subjective fancies rarely faUs to throw the mind out of balance ; it is at the bottom of all religious melancholia and suicidal mono- mania, as well as of many other forms of cerebral disease. For a dozen or fifteen years, Comte's life was such as to make a man insane, if anything, could ; and we should not forget, whatever may be the physiological significance of the fact, that in his early manhood he had experienced a violent attack of acute mania. His astounding self-conceit was more akin to that which may be seen in lunatic asylums than to anything which is known to have been manifested by persons in a state of health. I am strongly inclined to believe that the harmonious activity of his brain never fully recovered from the shock given it by that first attack. Very likely that attack is partly responsible for the self-brooding tendency which led him to abandon the world, and lead a secluded life among his own unbridled fancies. And it is not improbable that this long-continued self-communion carried him on the road to chronic subacute monomania, until, when he wrote the " Synthase Subjective," he had just overstepped the ill- defined limit which divides precarious cerebral health from pronounced cerebral disease. Nevertheless this hypothesis, though it seems most plausible, is perhaps not absolutely required by the facts. In this chapter we have seen how an exclusive reliance on the subjective method has bred in others, besides Comte, the most shocking' extravagances. It may be, after all, that Comte's vagaries are not so very much wilder than those of Hegel and Plato ; since Plato's absurdities are less in conflict with the scientific knowledge of the times in which they were conceived, and Hegel's are veiled by the dense obscurity of a pompous metaphysical terminology. When Hegel tells us that " Seyn ist Seyn, und nicht Anders : Anders ist Anders, und nicht Seyn " (Being is Being, and not CH. v.] THE TWO METHODS. 143 Otherwise : Otherwise is Otherwise, and not Being), we are overawed perhaps, but not immediately disgusted. There is an air of excessive profundity about tlie oracular dictum, and for a moment we think there may perhaps be something in it, which does not appear on the surface, — some occult verity which, as Hegelians tell us, fifty years more of enlighten- ment may enable us to realize. But Comte's thoughts are presented, not in the muddiest technical German, but in the clearest idiomatic French : when he makes the earth a fetish, and talks about a dance of the planets, the idea stands out . in all its naked absurdity. In spite of all this, however, I am inclined to believe that Comte sounded a deeper depth of extravagance than either Plato or Hegel. Insanity is, after all, only the excessive lack of correspondence between the order of conceptions and the order of phenomena. That is what we mean when we characterize it as delusion or hallucination. And when we avowedly employ a method which never deigns to adapt the internal order to the external order, there is no foreseeing the depth of the ditch in which we may be landed. The difference between the delusion which we regard as compatible with sanity, and that which we commiserate as insane, is mainly a difference of degree. And whether we are to call Comte crazy or not, is to a great extent a question of terminology. Certain it is, that if Adelung had lived to witness Comte's latest speculations, he might have found in them the materials for a more wonderful chapter than any of those now contained in his voluminous " History of Human Error." In these interesting vagaries we may find renewed evidence of the close kinship between the " dreams " of the ontologist, the fancies of the myth-maker, and the hallucinations of the insane, in so far as concerns the method employed. Never- theless it would be highly unjust to hold the Positive Philo- sophy responsible for these inanities, or for those of the pseudo-positivists who would seem to set larger store by 144 COSMIC PHILOSOPHY. [pt. i. their master's personal shortcomings than by his permanently valuable contributions to philosophy. Not only the disciple, but also the impartial critic, may fairly urge that the Positive Philosophy is something greater than Comte, just as the dif- ferential calculus is something greater than Newton or Leib- nitz. If Newton, in his old age, had become so far lost to all sense of scientific propriety as to apply his method of fluxions to the solution of physiological or ethical problems, much discredit would have attached to Newton, but none to the method of fluxions. Succeeding inquirers would have criticized him in the light of his own principles, and would have felt obliged to mourn the decadence of his godlike in- tellect, but the question would have been mainly a personal one, affecting in no way our estimate of the Newtonian mathematics. In like manner, when we characterize Comte's later speculations as vagaries hardly compatible with sanity, we cast no discredit upon the Positive Philosophy, since our whole argument implies that these speculations were con- ducted in utter disregard of those canons of research which it is the chief glory of the Positive Philosophy to have insti- tuted. It is one of Comte's most legitimate claims to im- mortal remembrance that, with greater authority and far ■wider scientific resources than Bacon, he succeeded in intro- ducing the objective method into departments of research where previously metaphysical interpretations had reigned supreme and unquestioned. For this he must ever be regarded as one of the worthiest among the " servants and interpreters of Nature." And it is mainly because of his pre-eminence as an inaugurator of scientific method that it has become customary to identify with Positivism every philosophy which, like the system expounded in this work, seeks to give synthetic expression to the ripest scientific thought of our age. If the question were only one of method, we might acquiesce in this identification. But, as I have already plainly indicated and shall presently show more fully, cii. v.] THE TWO METHODS. 145 our divergence from Positivism is so fundamental with re- gard to the deepest and gravest questions with which Philo- sophy is concerned, that, as Comte would unquestionably repudiate us as disciples, so do we unhesitatingly repudiate him as a master. VOL. I. CHAPTER VI. CAUSATION. In the course of our examination of the Kantian doctrine of Necessary Truths, the origin and justification of our belief in the necessity of causation was incidentally discussed. "We found that this belief can be explained and defended only as the product of a mental limitation due to absolute uniformity of experience. We believe that, under the requisite conditions fire burned before we were born, that it now burns in regions to which we have never had access, and that it will continue to burn as long as the world lasts, simply because we are in- capable of forming conceptions of which the materials are not supplied by experience, and because experience has never presented to our consciousness an instance of fire which, under the requisite conditions for burning, did not burn. Or, in other words, we believe that in the absence of preventive conditions, fire must always and everywhere burn, because our concept of fire is the concept of a thing which burns, and this concept has been formed exclusively by our experience of fire. You may, like a mediaeval sorcerer, envelope your hand in a soapy substance which will, for a few moments, check oxidation of the epidermis ; or you may insert your hand in the blaze and withdraw it again so quickly that, since chemical action takes time, oxidation will not have a CH. VI.] OAUl^ATION. 147 chance to begin, and your skin will escape ;— these are dis- turbing conditions. But to say that, in the absence of such conditions, the blaze will not burn your inserted hand, is to state a proposition which is unthinkable, — a proposition of which the elements cannot be united in thought save by their mutual destruction. Why is this proposition unthink- able ? It is because not only the material of our knowledge but our very mental structure itself, as I shall hereafter show, is due solely to that perpetual intercourse between subject and object which we call experience, so that, whatever verbal feats we may succeed in accomplishing, we can unite in thought no subject and predicate for the union of which ex- perience has not in some way or other supplied the condi- tions. I do not mean to say that the proposition in question is not one which some ingenious person might stoutly main- tain as a theory. We might, no doubt, hold the theory that Fire does not burn, just as we might espouse the doctrine that Triangles are circular, or that Matter is destructible. But as was sufficiently proved in the chapter on the Test of Truth, this shows only that it is possible for men to accept and defend propositions which they cannot truly conceive. It is easy to state the proposition that the Whole is equal to its Part ; but it is none the less impossible to think the thought or no-thought, which the proposition seeks to express. We are under a mental compulsion to think of the whole as greater than its part, and to think of fire as a thing which burns, because the conditions of our thinking have been pre- scribed by that intercourse between our mind and environing agencies, which we call experience. It is for the same reason that the mind is compelled to believe in the necessity of causation, and that the cultivated mind, which can realize all the essential conditions of the case, is compelled to believe in its universality. For what is the belief in the necessity and universality of causation? It is the belief that every event must be determined by some L 2 148 COSMIC PHILOSOPHY. [pt. i. preceding event and must itself determine some succeeding event. And what is an event ? It is a manifestation of force. The falling of a stone, the union of two gases, the blowing of a wind, the breaking of wood or glass, the vibration of a cord, the expansion of a heated body, the sprouting of a seed, the circulation of blood, the development of inflammation, the contracting of a muscle, the thinking of a thought, the excite- ment of an emotion, — all these are manifestations of force. To speak of an event which is not a manifestation of force, is to use language which is empty of significance. Therefore our belief in the necessity and universality of causation is the belief that every manifestation of force must be preceded and succeeded by some equivalent manifestation. Or, in an ultimate analysis, it is the belief that force, as manifested to our consciousness, can neither arise out of nothing nor lapse into nothing — can neither be created nor annihilated. And the negation of this belief is unthinkable ; since to think it would be to perform the impossible task of establishing in thought an equation between something and nothing. This, I suppose, is what Sir William Hamilton had in his mind when he asserted that our belief in the necessity and universality of caiisation is due to an original impotence of the conceptive faculty, — to our inability to conceive absolute beginning or absolute ending. In his examination of Hamil- ton's philosophy, Mr. Mill has made sad havoc of some of the crude and hasty statements, and yet more unfortunate theo- logical illustrations, in which Hamilton couched this doctrine ; but the doctrine itself he seems to have misunderstood rather than refuted. His favourite argument — that at one stage of philosophic culture we can conceive what at an earlier or later stage we could not conceive — rests upon a confusion of language which I trust has been sufficiently shown up in the course of the foregoing discussion. As I have already said, the only kind of inconceivability which we can admit as such is an impotence which results from the very constitution of CH-vi.J CAUSATION. 149 the thinking process. As was shown in the first chapter on the Eelativity of Knowledge, this is the case with our inability to conceive absolute beginning or absolute ending. "We must therefore, to a certain extent, accept the Hamiltonian doctrine that our belief in the necessity and universality of causation is due to an original impotence of the conceptive faculty; save that an ultimate psychological analysis obliges us to re- gard this original impotence as simply the obverse of our inability to transcend our experience. Here again we come upon a bit of common ground which underlies two opposing philosophies. For our last sentence, in its assertion and in its proviso, recognizes both aspects of the universal truth of which Kant and Hamilton on the one hand, and Hume and Mill on the other hand, have persisted in recognizing only one aspect. Here again we see exemplified what our sketch of the Newtonian discovery in the previous chapter taught us, — namely, the value of that objective method which, instead of ignoring an unexplained residuum, recog- nizes it as justifying further research. The unexplained residuum in the present case was the coexistence of an element of necessity in a given belief with an experiential origin for the belief Following the subjective method, Hume denied the necessity, Kant denied the experiential origin. But the objective method, recognizing the coexistence of the two as a fact to be accounted for, and employing a psycho- logical analysis inaccessible to Hume and Kant, discovers that the necessity of the belief and its experiential origin are but two sides of the same fundamental fact. From the origin and justification of our belief in causation, let us now pass to the contents of the belief. Since there is nothing in the belief that has not been given in ex- perience, let us endeavour to state what is and what is not given in our experience of an act of causation. In the first place sequence is clearly given in the phenomenon. " Even granting that an effect may commence simultaneously with 150 COSMIC PHILOSOPHY. [pt. i its cause," this view is in no way practically invalidated. As Mr. Mill says, "Whether the cause and its effect be necessarily successive or not, the beginning of a phenomenon is what implies a cause, and causation is the law of the succession of phenomena. ... I have no objection to define a cause, the assemblage of phenomena, which occurring, some phenomenon invariably commences, or has its origin. Whether the effect coincides in point of time with, or im- mediately follows, the hindmost of its conditions, is imma- terial. At all events it does not precede it ; and when we are in doubt, between two coexistent phenomena, which is cause and which is effect, we rightly deem the question solved if we can ascertain which of them preceded the other." 1 Secondly, invariableness of sequence is given in our ex- perience of causation. Invariableness is the chief mark by which we distinguish those sequences which are causal from those sequences which are commonly termed accidental. The well-known fallacy of post hoc, ergo propter hoc, upon which are founded most of the current hygienic and thera- peutic vagaries which claim to be upheld by experience, arises from the neglect of this essential distinction. It lumps together all kinds of sequence under the general head of causation. If drinking a cup of coffee is followed by headache, or if a troublesome fit of indigestion ends after taking a dose of patent medicine, it is rashly inferred that the coffee caused the headache, or that the medicine cured the indigestion. This is not legitimate induction. The sequence may be accidental and not causal. The headache may have been caused by eating hot risen biscuit, by inhaling carbonic oxide sent up from the furnace, by overwork, or by loss of sleep ; or it may be the premonitory symptom of a typhoid fever due to imperfect drainage. The indigestion may have been cured by a ride on horseback, or by a walk ^ Mill, System of Lnrjk, 6th edit. vol. i. p. 384. CH. VI.] CAUSATION. 151 on a frosty morning, or by a piece of good news, or by a rhythmical increase in the rate of nutrition for which no definite external cause is assignable. It is the business of induction to eliminate, as far as possible, all these coexistent possible causes, so as to ascertain, after the elimination, whether the sequence between the presumed cause and the effect is invariable. If it turns out to be so, and, still better, if by reasoning deductively from the experimentally-ascer- tained action of the coffee or the medicine upon the organic tissues involved in the case, further proof of the invariable- ness of the given sequences can be obtained, — then we say that we have detected a case of true causation. When we have extended our inquiries in any case so far as to be able to predicate invariable sequence, then we predicate causation. A moment's reflection, however, will show us that there are sequences which have been invariable throughout the whole course of human experience, but which are not re- garded as causal sequences. Ever since there have been conscious minds to interpret phenomena, day has followed night, and night has followed day, and yet no one would say that day causes night, or that night causes day. In order to include such cases as this, we must limit still further our definition of causation. The sequence must be uncon- ditional as well as invariable. This, as Mr. Mill observes, "is what writers mean when they say that the notion of cause involves the idea of necessity. If there be any mean- ing which confessedly belongs to the term ' necessity,' it is unconditionalness?- That which is necessary, that which must be, means that which wiU be, whatever supposition we may make in regard to all other things. The succession of day and night evidently is not necessary in this sense. It is conditional on the occurrence of other antecedents. That which will be followed by a given consequent when, and ' This, it will be seen, agrees with Mr. Lewes's admirable view of Neces- sity, cited above in Chapter III. 152 COSMIC PHILOSOPHY. [pt. i. only when, some third circumstance also exists, is not the cause, even though no case should ever have occurred in which the phenomenon took place without it." Now, either day or night " might have existed for any length of time, and the other not have followed the sooner for its existence : day follows night only if certain other antecedents [the presence of the sun above the horizon, and the absence of any eclipsing opaque body from the direct path of the solar rays] exist ; and where those antecedents existed, it would follow in any case. No one, probably, ever called night the cause of day ; mankind must so soon have arrived at the very obvious generalization, that the state of general illumination which we call day would follow from the presence of a sufficiently luminous body, whether darkness had preceded or not." Mr. Mill's further explanation of this point is so luminous that I prefer to cite it in his own words, rather than to abridge and dilute it. " To some," says Mr. MiU, " it may appear that the sequence between night and day being in- variable in our experience, we have as much ground in this case as experience can give in any case, for recognizing the two phenomena as cause and effect ; and that to say that more is necessary — to require a belief that the succession is unconditional, or in other words that it would be invariable under all changes of circumstances, is to acknowledge in causation an element of belief not derived from experience. The answer to this is, that it is experience itself which teaches us that one uniformity of sequence is conditional and another unconditional. When we judge that the succes- sion of night and day is a derivative sequence, depending on something else, we proceed on grounds of experience. It is the evidence of experience which convinces us that day could equally exist without being followed by night, and that night could equally exist without being followed by day. To say that these beliefs ' are not generated by our mere observation of sequence,' is to forget that twice in every twenty-four CH.vi.] CAUSATION. 153 hours, when the sky is clear, we have an cxperimentum crucis that the cause of day is the sun. We have an experimental knowledge of the sun which justifies us on experimental grounds in concluding, that if the sun were always above the horizon there would be day, though there had been no night, and that if the sun were always below the horizon there would be night, though there had been no day. We thus know from experience that the succession of night and day is not unconditional. Let me add, that the antecedent which is only conditionally invariable, is not the invariable antecedent. Though a fact may, in experience, have always been followed by another fact, yet if the remainder of our experience teaches us that it might not always be so followed, or if the experience itself is such as leaves room for a possibility that the known cases may not correctly represent all possible cases, the hitherto invariable antecedent is not accounted the cause : but why ? Because we are not sure that it is the invariable antecedent." Furthermore let it be noted that " such cases of sequence as that of day and night not only do not contradict the doctrine which resolves causation into invariable sequence, but are necessarily implied in that doctrine. It is evident, that from a limited number of unconditional sequences, there will result a much greater number of conditional ones. Certain causes being given, that is, certain antecedents which are unconditionally followed by certain consequents; the mere coexistence of these causes will give rise to an un- limited number of additional uniformities. If two causes exist together, the effects of both will exist together ; and if many causes coexist, these causes wiU give rise to new effects, accompanying or succeeding one another in some particular order, which order will be invariable while the causes continue to coexist, but no longer. The motion of the earth in a given orbit round the sun, is a series of changes which follow one another as antecedents and consequents, 154 COSMIC PHILOSOPHY. [ft. i. and will continue to do so while the sun's attraction, and the force with which the earth tends to advance in a direct line through space, continue to coexist in the same quantities as at present. But vary either of these causes, and the unvary- ing succession of motions would cease to take place. The series of the earth's motions, therefore, though a case of sequence invariable within the limits of human experience, is not a case of causation. It is not unconditional." ^ Jidy does not cause August, though it invariably precedes it. Por the sequence is conditioned by the coexistence of a given ratio between the solar gravitation and the earth's tangential momentum, with a given inclination of the earth's axis of rotation to the plane of its orbit. Vary either of these factors, which are the real causes of the seasons, and the hitherto invariable sequence between July and August will be altered. Causation may therefore be defined as the unconditional invariable sequence of one event, or concurrence of events, upon another ; and this is all that is given in the pheno- menon. But metaphysics is not content with this conception of Cause. It prefei'S to regard causation as a kind of con- straint by which the antecedent event obliges the consequent event to follow it. It postulates a hidden power, an occulta vis, in the cause, which operates as an invincible nexus between it and the effect. And it is by virtue of the exer- tion of this occult energy that cause, as formulated by meta- physics, is called Efficient Cause, in distinction from the only cause known to science, — the unconditional invariable ante- cedent, which may be termed Phenomenal Cause. This explanation bears the distinctive marks of a meta- physical hypothesis, as enumerated in the preceding chapter. To the elements of sequence, invariableness and uncondi- tionalness embraced in the scientific explanation, it superadds an occvilta vis, an element which is not given in the pheno- 1 Mill, SysUm of Logic, 6th edit, vol. i. pp. 379-381. CH. VI.] CAUSATION. 155 menon. No one pretends that we can actually cognize this occulta vis. The deepest analysis of our experience of the act of causation will yield no such element. Viewed under its subjective aspect, our knowledge of causation amounts simply to this, — that an experience of certain invariable sequences among phenomena has wrought in us a set of corresponding indissolubly coherent sequences among our states of con- sciousness ; so that whenever the state of consciousness answering to the cause arises, the state of consciousness answering to the effect inevitably follows. But answering to the occulta vis we have no state of consciousness whatever. Moreover the hypothesis of an occulta vis, like so many other metaphysical hypotheses, straightway lands us in an impossibility of thought. The proposition that the cause constrains the effect to follow, is an unthinkable proposition ; since it requires us to conceive the action of matter upon matter, which, as we saw in our first chapter, we can in nowise do. As was there pointed out, neither by the artifice of an intermolecular ether or of centres of attractive and repulsive force, nor by any other imaginable artifice, can we truly conceive one particle of matter acting upon another. What we do know is neither more nor less than what is given in consciousness, namely, that certain coexistences invariably precede or follow certain other coexistences. That matter as objectively existing may exert upon matter some constrain- ing power which, as for ever unknowable by us, may be called an occulta vis, I readily grant. Thought is not the measure of things, and it was therefore unphilosophical in Hume to deny the existence of any such unknown power. Things may exist, in heaven and on earth, which are neither dreamt of in our philosophy nor conceivable by our intelligence. Eespecting the external reality we say nothing : we only affirm that no such occulta vis is given in the phenomenon of causation. Any hypothesis which postulates such an unknown element as a means of explaining the phenomenon 156 COSMIG PHILOSOPHY. [pt. i. is unverifiable and, as such, science cannot admit it, nor can our Cosmic Philosophy admit it. Nevertheless the belief that causation implies something more than mere invariability of sequence, has been a persist- ent belief; and as such, it is a fact which philosophy is required to account for. Its explanation will not be difficult if we look to the source from which our notion of Power is derived. That source is the peculiar class of states of con- sciousness which accompany our voluntary actions. Part of our notion of Power consists in our consciousness of an ability to generate certain muscular sequences by means of an act of volition ; and this amounts to no more than an expectation that the antecedent, volition, will be followed by the consequent, muscular movement. But the other part of our notion of Power is derived from the sense of effort which invariably accompanies our muscular actions. Every such action " has to contend against resistance, either that of an outward object or the mere friction and weight of the moving organ ; every voluntary motion is consequently attended by the muscular sensation of fatigue. Effort, considered as an accompaniment of action upon the outward world, means nothing to us but those muscular sensations." ^ Here, then, is the shape of our primitive conception of Power ; the con- sciousness of volition, accompanied by the conscious sensa- tion of effort overcoming resistance, and the conscious expec- tation of a consequent muscular movement. ISTow, by the very relativity of our thinking, as will be shown more fully in the next chapter, we are compelled to formulate our con- ce]ption of the Power which is manifested in the sequence of external phenomena, in terms of that Power which is alone directly known to us in consciousness. Hence, when we see one object moved by another, we conceive the impelling object as putting forth effort and overcoming the inertia of the impelled object. Though we no longer, like some chil- 1 Mill, Examinalion of Hamillon's Philosophy, vol. ii. p. 47. en. vi.J OAUSATION. 157 dren and all savages, regard this as a conscious effort, attended by volition, we still conceive it as an effort attended by resistance. And from this anthropomorphism of thought are derived two closely related, though apparently incompa- tible, metaphysical theories ; the theory that matter, regarded as a cause, is endowed with an occulta vis ; and the theory that matter, regarded as an effect, can move only under con- straint from without. Such is the origin of our conception of power in causation. Yet that the conception, as thus formulated, cannot corre- spond to the external reality, is a truth so obvious, at the present stage of our discussion, as hardly to need pointing out. It is enough to remark that since effort, as known to us, is only an affection of our consciousness, we cannot conceive the wind which overturns a tree as exerting effort, unless we mentally endow the wind with consciousness. The primitive man did not scruple at this ; to him the Wind was a superhuman person. We, who have outgrown fetishism, must take the other horn of the dilemma, and admit that whatever may be the force which the wind exerts, it cannot be the force which we know as effort. By this alternative difficulty we may recognize the fact that we have here again come face to face with the Unknowable. What the process of causation is in itself we cannot know. We can know it only as it is presented to our consciousness, as the uncon- ditional invariable sequence of events. Our account of causation would not be complete without some mention of an attempt which has again been made, of late years, to pass beyond the limits of intelligence, and cognize the external process in itself This attempt, based upon an imperfect apprehension of the foregoing analysis, starts with the assertion that in our primitive consciousness of Power we have a true cognition of an Efficient Cause. According to this doctrine, the expectation that effort will overcome resistance and cause motion is a bit of d priori knowledge 158 COSMIC PHILOSOFHY. [pt. i. not given in experience. In our consciousness of effort we have direct knowledge of the causal nexus between the ante- cedent, volition, and the consequent, muscular contraction : volition is therefore known to us as an efficient cause of one kind of actions ; and hence we must infer that it is the sole efficient cause of all kinds of actions. Matter is absolutely inert : it is inconceivable that matter should act upon matter, but it is conceivable that mind should act upon matter ; and therefore all phenomena which are not the direct results of human or animal will, are the direct results of divine will. Such is the so-called Volitional Theory of Causation. With the theistic implications of this doctrine I shall deal in a future chapter. At present we are concerned only with its psychological basis. And first we may observe that those who assert the action of mind upon matter to be conceivable, appear to have forgotten the great difficulty under which metaphysics laboured during the seventeenth century. To Leibnitz and the Cartesians the action of mind upon matter was the thing inconceivable above all others, to account for which two theories were framed, among the most remarkable in the annals of metaphysics. These are, the doctrine of Occasional Causes, expounded by the Cartesian Malebranche, and the doctrine of Pre-established Harmony, expounded by Leibnitz, who is said to have plagiarized it from Spinoza. The Cartesians held it to be inconceivable, and therefore (on the subjective method) impossible, that thoughts or feelings in the mind should produce movements in the body; and consequently they regarded the concurrence of mental and material facts " as mere Occasions on which the real agent, God, thought fit to exert his power as a Cause." So that, when you will to raise your arm, God interposes and lifts the arm for you ; and he does this, not as a Being endowed with volition, but as an omnipotent Being, capable of working a miracle. To Leibnitz this seemed an unworthy view of divine action. He preferred to regard the entire series of CH. VI.] CAUSATION. 159 volitions and the entire series of apparentlj' consequent mus- cular motions as independent series, pre-established in har- mony with each other by the contrivance of the Deity from a time preceding the commencement of the world. So that, when you will to raise your arm, the arm moves, because God in the past eternity constructed the series of your volitions and the series of your motions like two clocks which accu- rately correspond to each other in their rates of ticking. Such theories as these can, of course, be neither proved nor disproved. They are cited as interesting specimens of the manner in which human speculation attempts to grapple with realities which lie beyond its reach ; but, as being un- verifiable, our philosophy cannot recognize them as legiti- mate hypotheses. Coupling them with the Volitional Theory, the result is mutual destruction. In point of fact, we are no more directly cognizant of the action of mind upon matter than we are directly cognizant of the action of matter upon matter. " Our will causes our bodily actions in the same sense (and in no other) in which cold causes ice, or a spark causes an explosion of gunpowder." The antecedent, volition, and the subsequent, muscular movement, are subjects of con- sciousness. But the relation of invariable sequence between them is known by experience, just as we know any other relation of sequence. As Mr. Mill observes, it cannot be admitted " that our consciousness of the volition contains in itself any d priori knowledge that the muscular motion will follow. If our nerves of motion were paralyzed, or our muscles stiff and inflexible, and had been so all our lives, there is no ground for supposing that we should ever (unless by information from other people) have known anything of volition as a physical power, or been conscious of any tendency in feelings of our mind to produce motions of our body, or of other bodies.''^-. In such case we might still have had a sensation, like that which we now term the ^ System of Logic, 6th edit. vol. i. p. 391. 160 COSMIO PHILOSOPHY. [pt. i. "consciousness of effort/' but we should have known it merely as " a feeling of uneasiness, accompanying our feel- ings of desire." As Sir William Hamilton acutely observes, the Volitional Theory " is refuted by the consideration, that between the overt act of corporeal movement of which we are cognizant, and the internal act of mental determination of which we are also cognizant, there intervenes a numerous series of intermediate agencies of which we have no [direct] knowledge; and, consequently, that we can have no con- sciousness of any causal connection between the extreme links of this chain, the volition to move and the limb moving, as this hypothesis asserts. No one is immediately conscious, for example, of moving his arm through his volition. Previously to this ultimate movement, muscles, nerves, a multitude of solid and fluid parts, miist be set in motion by the wiU, but of this motion, we know, from consciousness, absolutely nothing. A person struck with paralysis is conscious of no inability in his limb to fulfil the determinations of his will ; and it is only after having willed, and finding that his limbs do not obey his volition, that he learns by this experience, that the external movement does not follow the internal act. But as the paralytic learns after the volition that his limbs do not obey his mind, so it is only after volition that the man in health learns that his limbs do obey the mandates of his will." ' To this crushing refutation it may be added that even if volition were the efficient cause of our own movements, as we admit it to be the phenomenal cause, it would not follow that it is the cause of anything else. As the passage just cited from Hamilton shows, the only direct effect which volition can be'known to produce, is nervo-muscular action, — a very excep- tional, peculiarly animal, phenomenon. And yet, " because this is the only cause of which we are conscious, being the ^ Lectures on Metaphysics, Leot. 39 ; see also Dim^rtations to Reid, pp. 866, 867. cii. VI.] CAUSATION. lf;i only one of which in the nature of the case we can be con- scious, since it is the only one which exists within ovir- selves," — we are asked to assume, without further evidence, that throughout the infinitely multitudinous and hetero- geneous phenomena of nature, no other kind of cause exists ! A more amazing example of the audacity of the subjective method could hardly be found. In Mr. Mill's forcible lan- guage, " the supporters of the Volition Theory ask us to infer that volition causes everything, for no reason except that it causes one particular thing ; although that one plienomenon, far from being a type of all natural phenomena, is eminently peculiar; its laws bearing scarcely any resemblance to those of any other phenomenon, whether of inorganic or of organic nature." Thus ends in signal failure the last of the many attempts which have been made to invalidate the principle of the Eelativity of Knowledge. Start from what point we may, we must sooner or later reach the periphery of the circle which includes all that is knowable. Every attempt to overstep this periphery, and gain a sure foothold in the dark region beyond, must result in utter discomfiture. The in- quiry into the origin and contents of our belief in Causation reveals, more clearly than ever, our impotence to deal with objective powers and existences. The attempt to detect the occulta vis or hidden energy in the act of causation, is but the fruitless attempt to bind in the chains of some thinkable formula that universal Protean Power, of whose multitudinous effects we are cognizant in the sequence of phenomena, but which in its secret nature must ever mockingly elude our grasp. VOL. I. .\i CHAPTER VII. ANTHROPOMORPHISM AND COSMISM. The body of pliilosoptic truth contained in the six fore- going chapters can in nowise claim Auguste Comte as its originator. The doctrine of the relativity of knowledge has, as we have seen, been accepted more or less unreservedly by most of the thinkers of the last two centuries ; and has, indeed, never been wholly lost sight of in philosophic specula- tion since the time of Protagoras. Nevertheless the doctrine has been variously interpreted by different philosophers ; and we have seen that the Positivist interpretation of it, propounded by Littr^ and Mill, is essentially different from the interpretation given by Mr. Spencer, and here adopted. Again, the doctrine that all knowledge is the product of the intercourse between the sentient organism and its environ- ment is a doctrine which has been held by more than half the philosophic world since the time of Locke. The doctrine that causation, as cognizable by us, is merely unconditional invariable sequence was the doctrine of Hume, Brown, and James Mill ; and for its further defence and elucidation we are indebted, not to Comte, but to John Staart MU]. The test of truth, as stated in the third chapter of this work, was ' just as much or just as little postulated by Comte as by preceding thinkers : it was first definitely propounded by Mr. Spencer, and its validity has been repeatedly challenged by CH. VII.] ANTHROPOMORPHISM AND COSMISM. 163 Mr. Mill, — the most eminent psychologist who has yet de- clared his assent to all the fundamental doctrines of Positivism. Nor was Comte the first to insist upon the exclusive use of the objective method in all departments of research; for Bacon, as we have seen, had enunciated this precept with equal vigour and impressiveuess, though with less command- ing scientific authority. It is to be regretted, moreover, that we cannot even accredit Comte with unflinching loyalty to this principle. Not only have we seen him openly disavow- ing it, but we have been called upon to contemplate, in his "Subjective Synthesis," the most lamentable instance afforded by history of the wonderful extent of aberration possible to the intellectus sibi pcrmissus. All the above truths, then, so far as they were understood by Comte, were accepted by him as he found them. He did not originate them, nor did he place them, from the psycho- logical point of view, upon any surer footing than they had occupied before. That psychological analysis, in the light of which they have been here exhibited, and by which alone they can be securely established, Comte unreservedly and disdainfully repudiated. Asserting as he did that all direct observation and comparison of states of consciousness is vain and nugatory, Comte could only accept the doctrine of the relativity of knowledge and its corollaries as empirical doctrines. We shall frequently have occasion to remark upon the vulnerable condition in which the Positive Philo- sophy is left, owing to this disregard of psychology. Here indeed was Comte's weak point, as it is Mr. Spencer's strong point. As an observer and interpreter of states of conscious- ness Comte was below mediocrity — hardly fit to be ranked with Cousin or Dugald Stewart ; while, in power of psycho- logical analysis, Herbert Spencer has been surpassed by no thinker that ever lived, and has been rivalled only by Aris- totle, Berkeley, and Kant. And it is accordingly not Comte, but Spencer, who has wrought the truths above enumerated M 2 166 COSMIC PHILOSOPHY. fPT. i. Now I say it was by dint of this rare historic sense that Comte succeeded in taking a step which was not only an important advance, but in many respects a veritable revolu- tiou in philosophy. It was Comte who first brought into prominence the idea of a philosophy of history which should also be the history of philosophy. The thinkers of the eighteenth century, with Hume at their head, had studied systems of philosophy, much as anatomists before Cuvier had studied animal and vegetal organisms, as detached in- dependent existences, without regard to their past or future. But to Comte is due the grand and luminous conception of a historic development of thought, from the earliest to the latest ages of human speculative activity. Just as Cuvier proclaimed it irrational to study existing organisms without constant reference to extinct organisms, Comte pronounced it irrational to coordinate existing opinions, save in their rela- tion to past opinions. He grasped, as it had not before been grasped, the truth that each body of doctrines has its root in some ancestral body of doctrines ; that throughout the whole of man's speculative career there has been going on an Evolu- tion of Philosophy, of which the thorough recognition of the relativity of knowledge must be the inevitable outcome. Herein lay the originality of Comte ; an originality of which it is hardly correct to say that Prof. Huxley disparages it, since he passes over it in silence and does not appear to have discerned it. Yet as to the originality of this conception, there can be no question whatever. Neither Hume nor any other thinker of the eighteenth century had compassed it. Lessing, indeed, — a man far in advance of his age, — had, in his work entitled " The Education of the Human Eace," sketched a theory of the evolution of speculative ideas ; but it was only imperfectly, if at all, that he comprehended the nature and direction of that evolution. He may be regarded as a forerunner, but not as an anticipator, of Comte. As to the importance of Comte's conception there can be CH. VII.] ANTHROPOMORPHISM AND COSMISM. 167 no more question than as to its originality. It constituted a revolution in philosophy as thorough and wide-reaching as the revolution which Cuvier, by fusing together the studies of comparative anatomy and palaeontology, brought about in biology. In working out the details of his conception, Comte, like Cuvier, fell into many grave errors : but the great thing was, to have framed the conception. As Mr. Spencer wisely and wittily observes, "Inquiring into the pedigree of an idea is not a bad means of estimating its value." Comte's conception of the evolution of philosophy obliges us henceforth to test ideas by their pedigree, — to trace their origin in the employment of the subjective or of the objective method. Surely it was no small achievement to bring together the truths which Locke and Hume and others had laboriously detected, and to exhibit them as the necessary outcome of twenty-five centuries of speculative activity. For by this proceeding the truths in question were at least historically justified. And although the psycho- logical justification of them had to be left for Mr. Spencer, although it can be amply proved that Comte, in his ignorance of psychology, seriously misinterpreted the import of these truths, that is no reason why we should hesitate to acknow- ledge the greatness of his achievement. The doctrine of which Cuvier was the most eminent upholder — the doctrine of fixity of species — is one which modern biology rejects, just as modern philosophy rejects the doctrines especially characteristic of Comte's system. Nevertheless, as we admit of Cuvier, that his innovation, in studying all existing organisms with reference to past organisms, amounted to a revolution in the attitude of biology ; so we must admit of Comte, that his innovation, in studying all phases of thought with reference to preceding phases of thought, amounted to a revolution in the attitude of philosophy. Yet the latter admission no more makes us followers of Comte than the former admission makes us followers of Cuvier. 168 COSMIC PBILOSOPHY. [ft. r. The significance of this illustration will become still more apparent as we proceed to examine the attempt of Comte to describe the course of philosophic evolution as actually shown in history. According to Comte there are three modes of philosophizing — the Theological, the Metaphysical, and the Positive. The first two modes are characterized by the attempt to formulate the unknowable Cause or causes of phenomena ; but Positivism, recognizing the futility of all such attempts, ignores the unknowable Cause or causes of phenomena. Positivism limits itself to ascertaining uni- formities of coexistence and sequence among phenomena. Metaphysics and Theology superadd investigations concern- ing the nature of the hidden efficient cause of the pheno- mena; but Metaphysics regards this cause as a mere abstract entity, while Theology regards it as endowed with volition and intelligence. There are three successive stages of theology ; Fetishism, in which phenomena, being not yet generalized, are regarded each as endowed with a volition of its own; Polytheism, in which generalized groups of pheno- mena are regarded each as under the control of a presiding deity endowed with volition ; and Monotheism, which arises when men have gained the conception of a Universe, and have generalized the causes of phenomena until they have arrived at the notion of a single First Cause. According to Comte, philosophy began in fetishism ; as science progres- sively arranged phenomena in groups of wider and wider generality, philosophy passed through polytheism into mono- theism ; and as with its increasing generality, the primitive anthropomorphic conception of cause faded away, becoming replaced by the conception of an unknowable Cause mani- fested in phenomena, philosophy became metaphysical : finally, when the unknowable Cause is wholly ignored, and no account is taken of anything beyond the immediate con- tent of observed facts, philosophy becomes positive. For while Comte did not follow Hume and Berkeley to the ex- CH. VII.] ANTHROPOMORPHISM AND COSMISM. 169 tent of explicitly or implicitly denying tlie independent existence of a Power manifested in phenomena; while he would, if consistent with his own principles, have regarded such a denial as an overstepping of the limits within which positive speculation should be confined ; it is none the less true that he ignored the existence of any such Power as completely as if he had held the extreme idealist doctrine which pronounces it a mere figment of the imagination. So utterly foreign to Positivism is Mr. Spencer's doctrine of the Unknowable, that M. Littre, who is of all living men the most thoroughly and consistently a Positivist, condemns it as a baseless metaphysical speculation. Such is the celebrated " Law of the Three Stages," which is regarded by Positivists as one of the greatest achieve- ments of the human mind, and which impartial criticism must regard as an achievement of sufficient importance to have wrought a complete revolution in the attitude of modern philosophy. That it also contains a large amount of truth, as a concise generalization of historical facts, can be denied by no competent student of history. But, while freely conceding all this, it will appear, on a closer examina- tion, that the doctrine in question is rather a foreshadowing of the true statement than the true statement itself; and that in one all-important particular it is utterly inadmissible. Let us begin by inquiring how far the progress of human thought, with reference to the unknown Cause or causes of pheno- mena, can be regarded as divisible into stages, and in what sense Comte really intended to assert that there are three stages. It is important that both these points should be determined, in order that our conception of the character of the speculative development may be rendered sufficiently precise, and in order to ascertain how far Comte understood that character. Upon this point, as upon many others, Comte has left on record assertions which, if literally interpreted, simply cancel 170 COSMIC PHILOSOPHY. [ft. i. each other. At the beginning of the " Philosophie Positive," he tells us that " the mind employs successively in each of its researches three methods of philosophizing, of which the character is essentially different and even radically opposed — first the theological method, then the metaphysical, lastly the positive. The theological system arrives at the highest per- fection of which it is susceptible, when it has substituted the providential action of a single Being for the capricious play of the innumerable independent deities which were primi- tively imagined. Likewise the perfection of the metaphysical system consists in conceiving, instead of many particular entities, one grand entity. Nature, as the source of all pheno- mena. Finally the perfection of the positive system would be to represent all observable phenomena as particular cases of a single general fact." And hence, says Comte, "these three general systems of conceptions concerning the ensemble of phenomena mutually exclude each other." Now Comte elsewhere mairitains that, so far from mutually excluding each other, the three methods of philosophizing have co- existed with each other since the dawn of speculation ; and that, in particular, the metaphysical method is merely a modification of the theological method. The truth is, however, that the so-called " Law of the Three Stages " was an empirical generalization from the facts of history, and that, with his customary indifference to psycho- logical interpretations, Comte did not concern himself with the character of the mental processes involved in the speculative progression which he sought to formulate. What Comte really saw was, that men, when they first began to speculate upon the phenomena of nature, imagined behind every phenomenon, save possibly a few of the most familiar ones, an impelling will, like the human will ; that, as the anthropomorphic character of this conception slowly faded away, it left the conception of a hidden Power or powers, to ascertain the nature of which was long supposed to be the CH. VII.] ANTHROPOMORPHISM AND GOSMISM. 171 legitimate business of philosophy ; and that, lastly, with the further progress of thought, philosophy must give up the attempt to ascertain the nature of this hidden Power or powers, and concern itself solely with coexistences and sequences among phenomena. All this is true so far as it goes, its confirmation being written on every page of history. Nevertheless, all this is but one side of the truth. The truth has another side, which Comte never saw, and which no writer of the Positivist school has ever given any evidence of discerning. What Comte did not see was, that from first to last there is no change in the nature of the psychological process ; and that, even at the last, the hidden Power under- lying and sustaining the world of phenomena can no more be ignored than at the beginning. Let us examine both these points, and note well their significance. In the first place there is no change in the nature of the mental processes concerned in the development. From first to last, whether we give a theological, a metaphysical, or a scientific explanation of any phenomenon, we are interpreting it in terms of consciousness. To recur to our old illustra- tion ; on seeing a tree blown down by the wind, the primitive man concludes that the wind possesses intelligence and exerts volition: he calls it Hermes, or Boreas, or Orpheus, and erects to it a temple, wherein by prayer and sacrifice he may avert its displeasure. In a later age the wind is no longer regarded as endowed with conscious volition ; but it is still regarded as exerting effort, and overcoming the forces which tend to keep the tree in its place. Obviously this is at bottom the same conception as its predecessor, save that it is less crudely anthropomorphic. Now in the scientific ex- planation, we omit also the conception of a specific nisus or effort, and regard the falling of the tree as an event invariably consequent upon the blowing of the wind with a given momentum. Here, perhaps, it may seem that we quite get rid of every subjective or anthropomorphic element. But 172 COSMIC PHILOSOPHY. [rT. i. this is a mistake. The use of the word " momentum " shows how we are compelled to conceive the event as a manifesta- tion of force. We may abolish the figment of a specific occulta vis; but, strive as we will, we cannot mentally represent the event otherwise than as a differential result of the excess of one quantum of force over another quantum of force. And what do we mean by force ? Our conception of force is nothing but a generalized abstraction from our sensations of muscular resistance. That such a conception is merely symbolic, that it does not truly represent the real force objectively existing, I have already shown. Neverthe- less, from the relativity of our thought, such is the only con- ception which we can frame. Therefore, I repeat, from first to last, whether we give a theological, a metaphysical, or a scientific explanation of any phenomenon, we alike interpret it in terms of consciousness. Whether we frame the crude conception of an arbitrary volition, or the refined conception of a uniformly conditioned force, we must equally admit that our subjective feelings are the only materials with which the conception can be framed. The consciousness of force remains dominant from first to last, and can be abolished only by abolishing consciousness itself. But now, in the second place, this final scientific conception of a uniformly conditioned force cannot even be framed save by postulating an unconditioned Power existing independently of consciousness, to which no limit is conceivable in time or space, and of which all phenomena, as known to us, are the manifestations. It was demonstrated above, in the fourth chapter, that without postulating such an Absolute Existence, we can frame no theory whatever, either of external or of internal phenomena, even our proof of the relativity of knowledge immediately becoming nonsense in such case. It was shown that the existence of such a Power independent of us is an element involved in our consciousness of our own existence — is, in short, the " obverse of our self-con- CH. VII.] AXTIIIiOFOMOIiPHISM AND COSMIUM. 173 sciousness." Thus the three stages disappear entirely, and the three terminal conceptions which are alleged as distinc- tively characteristic of the stages are seen to be identical. The God of the monotheist, the ISTature of the metaphysician, and the Absolute Being which science is compelled to postulate, differ only as symbols differ which stand for the same eternal fact. If there be any confusion still left regarding this point, it will be dispelled by the following citation from Mr. Spencer : — " The progress of our conceptions, and of each branch of knowledge, is from beginning to end intrinsically alike. There are not three methods of philosophizing radically opposed ; but one method of philosophizing which remains, in essence, the same. At first, and to the last, the conceived causal agencies of phenomena have a degree of generality cor- responding to the width of the generalizations which experiences have determined ; and they change just as gradually as experiences accumulate. The integration of causal agencies, originally thought of as multitudinous and local, but finally believed to be one and universal, is a process which involves the passing through all intermediate steps between these extremes ; and any appearance of stages can be but superficial. Supposed concrete and individual causal agencies coalesce in the mind as fast as groups of phenomena are assimilated, or seen to be similarly caused. Along with their coalescence, comes a greater extension of their individualities, and a concomitant loss of distinctness in their individualities. Gradually, by continuance of such coalescences, causal agencies become, in thought, diffused and indefinite. And eventually, without any change in the nature of the process, there is reached the consciousness of a universal causal agency, which cannot be conceived. "As the progress of thought is one, so is the end one. There are not three possible terminal conceptions ; but only a single terminal conception. When the theological idea of 174 COSMIC PHILOSOPHY. [pt. i. the providential action of one Being is developed to its ultimate form, by the absorption of all independent secondary- agencies, it becomes the conception of a Being immanent in all phenomena ; and the reduction of it to this state implies the fading-away, in thought, of all those anthropomorphic attributes by which the aboriginal idea was distinguished. The alleged last term of the metaphysical system — the con- ception of a single great general entity, Natuj-e, as the source of all phenomena — is a conception identical with the previous one : the consciousness of a single source which, in coming to be regarded as universal, ceases to be regarded as con- ceivable, differs in nothing but name from the consciousness of one Being manifested in all phenomena. And similarly, that which is described as the ideal state of science — the power to represent all observable phenomena as particular cases of a single general fact — implies the postulating of some ultimate Existence of which this single fact is alleged ; and the postulating of this ultimate Existence involves a state of consciousness indistinguishable from the other two." ' This completely unanswerable statement exhibits Mr. Spencer's unrivalled power of psychologic analysis in striking contrast to the weakness under which Comte laboured from his neglect of such analysis. And it shows that Comte's conception of the order of philosophic evolution was entirely inadequate, and in the most important point entirely erro- neous. It shows that the fundamental characteristic of Positive Philosophy, as asserted by Comte and as admitted by his followers, is the non-recognition of the absolute and infinite Power which is manifested in phenomena. Or, to use Mr. Spencer's words, the essential principle of Comte's philosophy is " an avowed ignoring of Cause altogether. For if it is not, what hecomes of Ms alleged distinction between the perfection of the positive system and the perfection of the metaphysical system ? " According to Comte's own definition, ' Speucsr : Recent Discussions, p. 124. CH. VII.] ANTHROPOMORPHISM AND COSMISM. ITS the terminal conception of the metaphysical system is that of a single great Entity or Existence as the source of all phenomena; and since we have here shown that this very conception is the final conception in which science also must rest, the only possible step in advance which cs n be taken by Positivism is the elimination of this conception altogether. Prof. Huxley is thoroughly justified, therefore, n describing the name Positivism as ^implying a system of thought which recognizes nothing beyond the observed contents of pheno- mena: this description would be acknowledged as strictly accurate by M. Littr^, and indeed expresses neither more nor less than that which Comte sought to express when he defined the perfection of the positive system to be the con- templation of all observable phenomena as particular cases of a single general fact, and omitted to add that this single fact must be alleged of some Existence of which all observable phenomena are manifestations. The "positive" stage of philosophizing is, therefore, something which never did exist and which never will exist. The " positive " method of philosophizing is simply an impossibility. The fundamental principle upon which the Positive Philosophy rests is the refusal to affirm that of which the affirmation is the funda- mental principle of aU knowledge, of all science, and of that Cosmic Philosophy which is the summing up of science. Thus, since Comte's positive stage must be set aside altogether, and since his metaphysical stage and his theo- logical stage alike end in positing Absolute Existence as the source of phenomenal existence, this being also the funda- mental postulate made by science, the three stages vanish altogether. As we saw, in our second chapter, that from lowest to highest the process of knowing is essentially one and the same, we now see that from beginning to end the progress of that kind of knowledge which we call philosophy is one and the same. There are not three successive ' or superposed processes. There is one continuous process, 1T6 COSMIC PHILOSOPHY. [pt. t. which (if I may be allowed to invent a rather formidable word in imitation of Coleridge) is best described as a con- tinuous process of deanthropomor'plnzation, or the stripping off of the anthropomorphic attributes with which primeval philosophy clothed the unknown Power which is manifested in phenomena. Or, to be still more accurate, we may de- scribe the process of philosophic evolution as a continuous integration, in thought, of causal agencies ; of which process the gradual deauthropomorphization of these agencies is the necessary symptom and result, — until, as the end of the process, when all causal agencies have become integrated in the conception of a single Causal Agency, the tendency to ascribe anthropomorphic attributes to this Agency has reached its minimum. We may now consider this process somewhat more in detail, as it has been concretely exemplified in history. And in doing this it will become apparent that, in spite of its vagueness, its inadequacy, and the fundamental error which vitiates it, the Comtean conception undeniably contained an adumbration of the truth. It recognized the process of deau- thropomorphization as historically displayed, though it did not interpret it psychologically. And in several of its minor statements, we can have no hesitation in admitting Comte's generalization to be thoroughly valid. It is, for example, a historical fact that monotheism was preceded by polytheism, and that polytheism was preceded by fetishism ; as indeed it was a psychological necessity that it should be so. Nor need we have any scruples about grouping these various forms of anthropomorphism under the general title of theology; or about employing the term " metaphysics " to designate that - imperfect phase of science in which the necessity for veri- fication is not yet recognized, and in which the limits to philosophic inquiry are as yet undetermined. It was in this sense that the term was defined in our fifth chapter, and it was in this sense that Newton used it in his famous objur- CH. VII.] ANTHR0P0M0BPHI8M AND COSMISM. 177 gation, " 0, Physics, beware of Metaphysics ! " The term, as thus defined, as well as the term " theology," belongs to the general vocabulary of modern philosophy ; and in using the two, we in nowise tacitly commit ourselves to the un- tenable hypothesis of the " Three Stages," while at the same time we are thereby enabled the better to sum up the facts which seemed to Comte to justify his generalization. Premising this, we may proceed to gather our illustrations » of the deanthropomorphizing process. And first let us note that theology, metaphysics, and science all have their com- mon starting-point in mythology. It is worthy of remark that at about the same time when Comte first announced his theory of the primeval origin of philosophy in fetishism, the greatest of modern scholars, Jacob Grimm, was beginning those profound inductive researches which ended in demon- strating the fetishistic origin of myths. The myths of anti- quity and of modern savagery constitute philosophy in its most primitive form, and embody whatever wisdom fetishism has to offer as the result of its meditations upon the life of man and the life of nature. Primitive men, like modern savages, had no systematic theology ; they possessed no sym- bolic conception of God as an infinite unity ; they were astray amid an endless multitude of unexplained and apparently unconnected phenomena, and could therefore form no gene- ralized or abstract notions of divinity. But they were " oppressed with a sensus numinis, a feeling that invisible, powerful agencies were at work around them, who, as they willed, could help or hurt them." They naturally took it for granted that aU kinds of activity must resemble the one kind with which they were directly acquainted — their own volition. Seeing activity, life and motion everywhere, it was impossible to avoid the inference that intelligent volition must be everywhere. Even after centuries of philosophizing, we can hardly refrain from imagining an anthropomorphic effort, or nisus, as constituting the necessary link between VOL. I. ' N 178 COSMIC PHILOSOPHY. [pt. i, cause and effect. Yet in our minds, in so far at least as our overt utterances are concerned, fetishism has been very nearly destroyed by the long contemplation of the unvarying uni- formity of the processes of nature. In the mind of the primi- tive man there were no such checks. The crude inference had its own way unopposed ; and every action was believed to have its volition behind it. There was a volition for sun- rise, and another for sunset ; and for the flood of rain and the lightning there was a mighty conflict of volitions, a genuine battle of manitous, or superior beings, whenever — in mythic phrase — the great black shaggy ram, lifting audaciously his moist fleece against the sky, was slain and annihilated by the golden, poison-tipped, unerring shafts of Bellerophon.^ Thus we may safely assert, with Comte, that the earliest attitude assumed by the mind in interpreting nature was a fetishistic attitude. That chaos which the oldest traditions and the latest science alike recognize as the primordial state of the material universe must also have characterized the infancy of the human intellect. Until phenomena had been partially generalized, they could only have been considered the manifestations of arbitrary powers, not only unallied, but even in conflict with each other. And psychology tells us ^ Thus, as I have observed in another work, ' ' a myth is an explanation, by the uncivilized mind, of some natural phenomenon ; not an allegory, not an esoteric symbol, — for the ingenuity is wasted which stiives to detect in myths the remnants of a refined primeval science, — but an explanation. Primitive men had no profound science to perpetuate by means of allegory, nor were they such sorry pedants as to talk in riddles when plain language would serve their purpose. Their miuds, we may be sure, worked like our own, and when they spoke of the far-darting sun-god, tliey meant just what they said, save that where we propound a scientific theorem, they constructed a myth. A thing ia said to be explained when it is classified with other things with which we are already acquainted. That is the only kind of explanation of which the highest science is capable. We explain the origin, progress, and ending of a thunder-storm, when we classify the phenomena presented by it along with other more familiar phenomena of vaporization and condensation. But the primitive man explained the same thing to his own satisfaction when he had classified it along with the well-known phenomena of human volition, by constructing a theory of a gi'eat black dragon pierced by the unerring arrows of a heavenly archer." — Myths and Myth-Malcers, p. 21. CH. VII.] ANTHROPOMORPHISM AND 008MISM. 179 that the fetishistio hypothesis was the only possible one, — that these powers must have been supposed to effect their purposes by means of volition. As we have seen, all inter- pretation of phenomena is an interpretation in terms of like- ness and unlikeness. We know an object only as this thing or that thing, only as classifiable with this or that other object; and the extent of our knowledge may be measured by the accuracy and exhaustiveness of our classification. To adopt a familiar expression of Plato, we are ever carrying on a process of dichotomy ; or, in the more precise language of modern psychology, we are continually segregating similar objects and similar relations of objects into groups, apart from those which they do not resemble. If we fail to detect the resemblances which really exist, or if we have imagined resemblances which do not exist, our interpretation is so far inaccurate and untrustworthy, but not therefore necessarily useless. Some theory is needful as a basis for further observation. Wrong classification is the indispensable pre- lude to right classification. The mind cannot go alone till it has for awhile groped and stumbled. ISTature, the hoary Sphinx, sternly propounds a riddle ; and many a luckless guesser gets devoured before an Oidipous arrives with the true solution. In the primitive hypothesis, therefore, the forces of nature must have been likened to human volition, because there was nothing else with which to compare them. Man felt within himself a source of power, and did not yet surmise that power could have any other source than one like that which he knew. Seeing activity everywhere manifested, and knowing no activity but will, he identified the one with the other; and thus the same mighty power of imagination which now, restrained and guided by scientific methods, leads us to dis- coveries and inventions, then wildly ran riot in mythologic fictions whereby to explain the phenomena of nature. The advance from this primeval fetishism through poly- N 2 180 COSMIC PHILOSOPHY. [ft. i. tbeism to monotheism was determined by the gradual attain- ment of physical knowledge, or, in other words, by the detection of certain uniformities in the processes of nature. The discovery of natural laws is the segregation of pheno- mena into groups according to their relations of likeness and unlikeness, attended by the disclosure of community of causa- tion for the phenomena constituting each group. After this process has continued for a time, it is perceived that there are different modes of causation. Phenomena, in the pro- duction of which the human will is not implicated, are seen to differ from those in which it is concerned, by exhibiting a more conspicuous and readily detected regularity of sequence. Consequently, in considering them, the conception of arbitrary or capricious will is gradually excluded, and is replaced by the conception of a uniform force, whose actions may be foreseen, and whose effects, if harmful, may be avoided. This having occurred in the case of the more familiar pheno- mena, the same result eventually follows in the case of those which are more remote. The ultimate phase of this process, characterized by the complete extrusion of volitional agencies and the universal substitution of the conception of invariable sequence, becomes possible only after an immense develop- ment of physical science. Volitional agencies, therefore, were not at once extruded, but were only generalized more and more, and gradually separated further and further from the phenomena which they were supposed to produce. A great step was taken in philosophy when the Titan dynasty was dethroned, and the celestial and terrestrial provinces - of phenomena partitioned between Zeus and Poseidon. A still greater step was taken when God, considered as an arbitrary volitional agency, was entirely separated from the universe of tolerably uniform sequences, interposing with his will only on rare occasions. This is the cruder form of mono- theism, and in it the metaphysical mode of thought is very conspicuous. In place of the innumerable volitional agents cii. vn.J ANTHROPOMORPHISM AND COSMISM. isi of the older theosophy, we have now innumerable occultce vires, inherent virtues, vital principles, essential properties, and abstract entities ; at the bottom of all the universal occult entity Nature, which is regarded as producing pheno- mena with considerable uniformity, save when the Volition be- hind sees fit to interpose and temporarily modify the natural order. Finally, when physical generalization has advanced so far as to include all, or nearly all, orders of phenomena, the theory of miraculous interposition vanishes, or remains only as a lifeless formula, verbally assented to, but not really believed in, while the presiding Volition is thrust back to the beginning of things, being retained only as a convenient and apparently necessary postulate by which to account for the origin of the universe and the harmonious cooperation of phenomena. This most refined form of theology will be thoroughly discussed in a future chapter. We have now only to note that further progress in deanthropomorphization involves the extrusion of the notion of a volitional Cause altogether, and leaves us with the conception of a Cause mani- fested throughout the entire world of phenomena, which is an indestructible element of consciousness, and which, equally with the anthropomorphic conceptions which have preceded it, is the proper object of religious feeling, but concerning the nature of which — in itself, and apart from its phenomenal manifestations — the human mind can frame no verifiable hypothesis. We have seen that this terminal phase of the deanthropo- morphizing process is radically distinct from Positivism, in which the Cause manifested in the world of phenomena is entirely ignored. It need hardly be added that it is equally distinct from Atheism and Pantheism, in which no place is left for a Cause distinct from phenomena themselves. How shall we characterize this terminal phase of the long process of philosophic development which we have just passed in rapid survey ? An answer will be forthcoming if we pause 182 COSMIC PHILOSOPHY. [pt. i. to consider the common characteristics of the theological phases of thought which, in this terminal phase, are assumed to be outgrown and superseded. Let us premise that the word " Cosmos " is, by virtue of its etymology and of strict scientific usage, the antithetical correlative to the word " Chaos." It denotes the entire phenomenal universe ; it connotes the orderly uniformity of nature, and the negation of miracle or extraneous disturbance of any kind. Now it is a common characteristic of the theologico-metaphysical phases ' i of philosophy above passed in review, that while they have sought to explain the universe of phenomena, their explana- tions have been not purely cosmic, but to a greater or less extent anthropomorphic. Instead of restricting themselves to the interpretation of the uniformities of coexistence and sequence discovered by science, they have had recourse to unveritiable hypotheses concerning supernatural beings and occult entities, and have thus complicated the conception of the Cosmos with that of anthropomorphic agencies that are extra-cosmic. We have seen that the process of scientific generalization, which underlies the evolution of philosophy from epoch to epoch, is characterized not by the elimination of these agencies, but by their integration into a single Agency, from which the an- thropomorphic attributes are stripped, and which is regarded as revealed in and through the Cosmos. Manifestly, then, while it is impossible to define this process as a development from Anthropomorphism to Positivism, it is on the other hand strictly accurate and entirely appropriate to define it as a development from Anthropomorphism to Cosmism. I do not know where we could find, for our purpose, a pair of terms more happily contrasted. Por besides the connota- tions just described, there is also involved in this termino- logy the recognition of the fact that, at the outset, men interpreted the Cosmos in terms of human feeling and volition ; while, on the other hand, as the newest result of scientific ^generalization, we now find them beginning to CH. VII.] ANTHROPOMORPHISM AND CO$MISM. 183 interpret human feeling and volition in terms obtained from the objective study of the Cosmos. Let it be noted also, that, along with this group of happy contrasts, there is an eq^ually happy lack of antagonism between our pair of terms. For while, on the one hand, all past philosophies have been Cosmic, in so far as the interpretation of the universe has been their aim ; on the other hand, it will never be possible to get entirely rid of every trace of Anthropomorphism. For, as was proved in the fourth chapter, there is anthropomorphism even in speaking of the unknown Cause as single ; and, as has been proved in the present chapter, there is anthropomorphism even in speaking of the unknown Cause as a Poiuer mani- fested in phenomena. Yet we must either use such language or remain silent ; we must either symbolize the unknown Cause or ignore it, — and as the latter alternative is impos- sible, we must accept the former. Thus is exhibited in strong relief the peculiar excellence both of our theory of deanthropomorphization, and of the terms in which it is stated. For whereas the Atheistic Philosophy current in the eighteenth century, sought to break entirely with the past, scornfully setting aside its time-honoured beliefs as so much quackery and delusion; and whereas the Positive Philosophy, in spite of its sym- pathetic attitude toward the past, consequent upon its announcing itself as the terminal phase of a long develop- ment, nevertheless was obliged tacitly to break with the past, in so far as it ignored that which in earlier stages had always been taken for granted ; on the other hand, the Cosmic Philosophy, in announcing itself as the most recent phase of a long development, recognizes no break anywhere in the course of that development. While Atheism scoffed at religion, and denied that the religious sentiment needed satisfaction ; while Positivism, leaving no place in its scheme for religion to occupy, was compelled by an afterthought to 1S4 COSMIC PHILOSOPHY. [pt. [. proclaim that the religious sentiment finds its legitimate satisfaction in the service of an idealized Humanity; Cosmism, on the contrary, assigns to religion the same iDlace which it has always occupied, and affirms that the religious sentiment must find satisfaction in the future, as in the past, in the recognition of a Power which is beyond Plumanity, and upon which Humanity depends. The existence of God — denied by Atheism and ignored by Positivism — is the fundamental postulate upon which Cosmism bases its syn- thesis of scientific truths. The infinite and absolute Power, which Anthropomorphism has in countless ways 'sought to define and limit by metaphysical formulas, thereby rendering it finite and relative, is the Power which Cosmism refrains from defining and limiting by metaphysical formulas, thereby acknowledging — so far as the exigencies of human speaking and thinking will allow — that it is infinite and absolute. Thus in the progress from Anthropomorphism to Cosmism the religious attitude remains unchanged from the beginning to the ,end. And thus the apparent antagonism between Science and Eeligion, which is the abiding terror of timid or superficial minds, and which the Positive Philosophy did comparatively little to remove, is in the Cosmic Philosophy utterly and for ever swept away. The further elucidation of these views must be postponed until we come to treat in detail of the relations of science to theism and religion. A^'ith this preliminary indication of a theory to be hereafter more fully unfolded, the present chapter might be brought to a close, were it not that our conclusions have been elicited through a criticism of the theory of Comte, and that, at the beginning of our discussion, certain expectations were held out which the close of the discussion may seem to have belied. Conformity to the requirements of sound criticism demands that something more should be said upon this point. Wc started in the belief that we were about to trace the . cTi. vu.] ANTHROPOMORPHISM AND COSMTSM. 185 outlines of some grand achievement whereby the claims of Comte to philosophic originality might be vindicated. We expressed entire dissent from Prof. Huxley's opinion that there is nothing of any value in the Positive Philosophy save that which it has borrowed from Hume. And we went so far as to assert that Comte's generalization of the historic order of speculative development inaugurated nothing less than a veritable revolution in the attitude of philosophy. Yet we have ended by regarding that generalization as wholly erroneous in one fundamental point, and as more or less inadequate in nearly all its points. And, more than this, we have noted that the very weakness of Comte's position con- sisted in his inability to advance one step in psychology beyond the point reached by Hume. In spite of all this, however, the essential importance of the step taken by Comte is in no way invalidated. It is one thing to show that a doctrine is not wholly true ; it is quite another thing to show that it contains no truth whatever. "When Copernicus, for example, asserted that the planets revolve about the sun in circular orbits, he made a statement which is false ; yet it is by virtue of his making this state- ment that we regard him as the inaugurator of the modern movement in astronomy. It was false that the planets revolve in circular orbits, but it was true that they revolve about the sun ; and this was the part of the statement which turned men's thoughts into a new channel. Now, while I do not believe that Comte will ever be regarded by posterity as the Kepler or the Newton of modern philosophy, it is not at all unlikely that he will be pronounced its Copernicus. Though he was wrong in asserting that in the course of speculative evolution there are three radically distinct stages, and wrong also in assuming that the consciousness of Absolute Exis- tence can ever be abolished ; he was right in asserting that there has been a definite course of speculative evolution, of which deanthropomorphization is an essential feature, and 186 COSMIC PHILOSOPHY. [pt. i. which must end in the complete rejection of ontology. A.nd this — though Prof. Huxley has not remarked it— was the part of his statement which called attention to the fact that a new era in speculation was commencing. I cannot, there- fore, unreservedly endorse Mr. Spencer's assertion that Comte, while accepting the doctrine of the relativity of knowledge and kindred doctrines of modern scientific philosophy, neverthe- less did nothing toward placing these doctrines upon a firmer ground than they had hitherto occupied. Comte indeed con- trihuted nothing whatever to the psychological justification or elucidation of these doctrines ; yet with his keen historic sense, he did much toward justifying them historically. To Hume's partial demonstration of the relativity of knowledge, Comte added incalculable weight by showing that toward the assertion of that doctrine tended the enormous momen- tum of twenty-five centuries of speculative activity. It is true that he proved this point only by an empirical induction from the facts of history ; and it is true that he only half understood and stated incorrectly the doctrine which he thus empirically confirmed. Nevertheless even this incomplete achievement was partly the symptom and partly the cause of a philosophic revolution, the character of which we shall more fully appreciate when we come in our final chapter to compare the critical attitude assumed by philosophy in our age with that which it assumed in the age of Eousseau and the EncyclopMistes. When we recollect how slow is the education of the human race, and how few are they who can serve efficiently as its teachers, we shall be inclined to admit the justice of the principle that great thinkers should be estimated rather according to what they have accomplished than according to what they have failed to accomplish. Historic criticism is at last beginning to learn this important lesson. And just as we freely admit that in those very speculations of Berkeley and Hume and Kant which we now reject, the point which riveted the attention of their authors CH. VII.] ANTRKOPOMOBPHISM AND COSMISM. 187 was a valuable truth, though not the truth which they sup- posed they saw ; in like manner we must admit that in that theory of Comte's which I have here adversely criticized, there was contained a fruitful germ of truth. CHAPTER VIII. ORGANIZATION OF THE SCIENCES. The results obtained in the course of the preceding inq^uiry have added depth and precision to our conception of the Scope of Philosophy. In coming to look upon all phenomena as manifestations of a Power unknowable in itself, yet know- able in the order of its phenomenal manifestations, we have- virtually come to declare that the true business of philosophy is the determination of the order of the phenomena^ in which this omnipresent Power is manifested. And thus we arrive by another road at the very same definition of Philosophy which was previously given ; and we see that the progress of deanthropomorphization, while leaving the religious attitude of philosophy entirely unchanged, has at the same time pre- cisely limited its scope in making it the Synthesis of the general truths of science into a system of universal truth. We have next to inq^uire — as preliminary to the constiuction of such a Synthesis — into the manner in which the different orders of scientific truths are to be grouped for the purposes of our philosophic construction. In short, we are brought face to face with the problem which also occupied Comte next in order after the question of deanthropomorphization : we have to deal with the classification of the sciences. And, as in the preceding chapter, we shall endeavour, while CH. vin.] OBGANIZATION OF THE SCIENCES. 189 adversely criticizing the Comtean theory, to elicit results which are both true and available for our subsequent inquiries. Comte begins by distinguishing two kinds of natural sciences ; the one kind abstract and general, having for their object the discovery of the laws to which the various orders of phenomena conform, in all conceivable cases ; the other kind concrete, special, descriptive, consisting in the appli- cation of general laws to the natural history of the various objects actually existing in the present or past. There is nothing difficult, or even novel, in this distinction, since it corresponds very nearly with that which is ordinarily drawn in scientific treatises between dogmatic physics and natural history. We shall see the difference very clearly by com- paring general physiology, on the one hand, with zoology and botany on the other. The one formulates the general laws of life, whether considered in equilibrium or in the process of development ; the other merely enumerates the conditions and mode of existence of each particular species of living bodies. Similar is the contrast between chemistry and mineralogy, of which the latter science is evidently founded upon the former. In chemistry we consider all possible combinations of heterogeneous molecules, in all imaginable circumstances ; in mineralogy we consider only the particular combinations which are found realized in the actual past or present constitution of the terrestrial globe, under the influence of special sets of conditions. A circumstance which well illustrates the difference between the chemical and the mineralogical point of view, although the two sciences deal with the same objects, is, that a large proportion of the facts contemplated in chemistry have only an artificial or experimental existence. So that, for example, a body like chlorine or potassium may possess great importance in chemistry by reason of the extent and energy of its reactions and its affinities ; while in mineralogy, on the other hand, it may be of little importance, because it is but seldom con- 190 COSMIC PHILOSOPHY. [ft. i. cerned in producing the natural rearrangements of molecules which it is the business of mineralogy to explain. And con- versely, some such compound as granite or feldspar, which fills a great place in mineralogy, may be of little interest from the chemical point of view. Of these two kinds of sciences, according to Comte, mani- festly it is the first kind which first needs to be classified and systematically studied in its doctrines and methods. The scientific study of concrete physics presupposes the scientific study of abstract physics. For example, the study of the geologic development of the earth, when prosecuted in the most comprehensive manner, requires not only the previous study of physics and chemistry, but also some previous knowledge of astronomy and physiology. And similarly the scientific study of oceanic and atmospheric currents, — which, in the present chaotic state of our nomenclature, we charac- terize variously as meteorology, or climatology, or include under physical geography, — demands a preliminary acquaint- ance not only with mechanics, chemistry, and all the branches of molecular physics, but also with astronomy, since climatic rhythms depend upon the inclination of the earth's axis to the plane of the ecliptic, and more remotely upon the varia- tions in that inclination known as precession and nutation. It is for this reason that concrete physics has made so little progress down to the present day, since it could begin to be rationally studied only after all the branches of abstract physics had assumed a distinctively scientific character. While, con- versely, as soon as abstract physics has been completely organized, the study of concrete physics becomes merely the detailed application of general principles already established. Prom these considerations Comte concluded that his Positive Philosophy might be founded upon a thorough organization of the doctrines and methods of the abstract sciences alone. The problem first in order was to arrange these sciences in a natural series. The end to be kept in view, in this encyclo- CH. viii.J ORGANIZATION OF TEE SCIENCES. 191 psedic labour, is to arrange the sciences in the order of their natural succession and mutual interdependence ; so that we may study and expound them one after the other, without ever being led into a zigzag or circular course of study and exposition. It should be mentioned here at the outset, that Comte did not regard such an end as strictly attainable, in all its rigorous precision. He tells us expressly that how- ever natural and however logically serviceable such a classi- fication may be, it must always and necessarily contain something that is arbitrary, or at least artificial, in its arrangements. This, as he clearly saw, must ever result from the very richness and complexity of ISTature, which refuses to be analyzed and partitioned off into distinct pro- vinces, save provisionally for convenience of study. In his Introduction he reminds us that so few as six fundamental sciences will admit of seven hundred and twenty different arrangements ; and that in behalf of each of these arrange- ments very likely something might be said, since even in the various classifications already proposed, the same science which one places at the beginning of the scale is by another placed at the end.^ Nevertheless there is one series which is clearly indicated by the decreasing generality and simpli- city of the phenomena with which the respective sciences are concerned. And this is the order which Comte adopts, primarily on account of its logical convenience. He begins with the most simple and general phenomena, to proceed step by step to those which are most complex and special. Proceeding upon this principle, we are confronted at once by two grand divisions of phenomena, inorganic and organic. There is no difficulty in deciding which of these to study first. The more general and simple phenomena of weight, heat, light, electricity, and chemism, are manifested alike by 1 Later in life Comte, no donbt, came to look upon his classification as complete and final. And so it appears to be regarded by his disciples, who are deaf to all the consideration.? which impeach it. 192 COSMIC PHILOSOPHY. [pt. i. not-living and by living bodies ; whereas tlie more special and complex phenomena of life are manifested, of course, only by the latter. Therefore the science of inorganic pheno- mena must precede the other. We can study thermal radia- tions and chemical reactions without taking vital forces into the account ; but we cannot study living organisms without appealing to physics and chemistry at every step. In the science of inorganic phenomena a somewhat less obvious principle of division next presents itself. Inorganic physics may be divided into celestial and terrestrial physics ; of which the first treats only of gravitative force as mani- fested in the relatively simple phenomena of the mutual attractions of the heavenly bodies ; while the second treats not only of gravitative force as manifested throughout rela- tively complex terrestrial phenomena, but also of the mole- cular forces, cohesion and chemism, and of the modes of undulatory motion called sound, heat, light, magnetism, and electricity. This second division may be again subdivided into physics proper and chemistry. The first treats of those changes in which the relative positions of the molecules of matter are altered homogeneously, resulting in increase or decrease of volume, or other change of physical state ; while the second treats of those changes in which the relative positions of molecules are altered heterogeneously, resulting in the production of new compounds and new affinities. Of these two sciences, manifestly physics should be first studied. We can to a certain extent generalize the laws of reflection and refraction, condensation and rarefaction, without help from chemistry ; but we cannot proceed a step in chemistry without appealing to physics. Turning now to organic phenomena, we perceive that living beings may be studied either individually or col- lectively. In the first case we generalize the laws of nutri- tion and reproduction, of muscular contractility and nervoiis sensibility. This is the province of biology, a science which CH. viii.] ORGANIZATION OF THE SCIENCES. 193 according to Comte, is of itself competent to include all the phenomena presented by vegetables and by the lower animals, as well as all those presented by individual man. But in the case of man, the aggregation of individuals gives rise to an entirely new class of phenomena produced by the reaction of individuals upon each other. To generalize the laws of this class of phenomena is the business of sociology, which is thus manifestly the most complex and special of the sciences. According to Comte, this disposes of all the fundamental abstract sciences, except mathematics. This science he places first of all, the phenomena of number and form being universal, and capable of generalization without reference to other phenomena. Thus we have the hierarchy of the positive sciences arranged in the following order : — I. Mathematics. II. Astronomy. III. Physics. IV. Chemistry. V. Biology. VI. Sociology. In each of these sciences, there are several subdivisions which Comte endeavours to arrange, wherever it is possible, according to the same general principle of convenience. In mathematics, he places algebra before geometry, on the ground that we can study number by itself, but in order to study form we must make use of sundry laws of number ; and for a similar reason, mechanics, which involves time and motion, is placed subsequent to the other two. In physics, barology, or the general doctrine of weight and pressure, is placed first, as nearest akin to astronomy ; and electrology is placed last, as nearest akin to chemistry. The intermediate branches, acoustics, optics, and thermology, would now be ranked in the order in which I have named them; but VOL. I. 194 COSMIC PHILOSOPHY. LrT. i. Comte ranked thermology first, probably because of^ the enthusiasm aroused in him by his friend Fourier's achieve- ment in bringing the general doctrine of thermal expansion and contraction so thoroughly under the sway of mathe- matical analysis. In biology, anatomy, or the study of structure, is placed before physiology, or the study of func- tion; and the study of the vegetal or nutritive functions precedes that of the animal or nervo-muscular functions. In sociology, the study of equilibrium, or the conditions essential to order, is ranked before the study of the laws of progress as generalized from history.^ It will be observed that in this scheme no special place is assigned to psychology. This is an omission quite in keep- ing with Comte's general conception of the scope of philo- sophic inquiry, from which the observation and analysis of states of consciousness are purposely omitted altogether. This omission will best be criticized and characterized later on, when in the course of our philosophic synthesis we shall have arrived at the discussion of the relations of the phe- nomena of mind to the phenomena of life.^ Meanwhile, merely noting this serious omission, we may observe that the classification just sketched is so fascinating in its sim- plicity, and so manifestly convenient for many practical purposes of research, that at first it seems almost a pity for criticism to invalidate it. Its leading features appear to speak for themselves, to carry their own recommendation with them, to characterize this classification as the best which, with our present resources, it is possible to frame. And, indeed, if we compare it with some of the most ambitious preceding classi- fications, such as those of Oken and Hegel; or even with ^ In a future chapter, it will appear that the proper arrangement is just the reverse of this, no sound theory of social equilibrium being attainable until the laws of progress have been generalized from history, with tlie aid of biology and psychology. Here, as in many other cases, Comte's error was due to his imperfect comprelicnsion of the principle of Evolution. 2 See below, part ii. cliap. xiv. cii. vni.] ORGANIZATION OF THE SCIENCES. 195 the less pretentious but more useful systems of D'Alembert, Stewart, Ampere, Geoffroy St. Hilaire, and Cournot; its superiority is at once apparent. The arrangement seems so natural and obvious that it has not unfrequently been cha- racterized by able critics as " j ast the sort of classification that would naturally arise in any reflecting mind on a review of the subject." We should not forget, however, that it never had arisen in any of the reflecting minds which re- viewed the subject previous to Comte. But Comte, who viewed everything in a historical light, intended that his classification should be something more than a convenient plan for arriving at philosophic generality through the study of the separate abstract sciences. He regarded it also as a kind of philosophic tableau or con- spectus of the progress of the human mind from anthropo- morphic toward scientific conceptions of natural phenomena. According to him, the order in which he arranged the sciences was the order in which they had respectively been constituted as sciences, — in which they had passed from the theological or metaphysical into the scientific stage. Thus mathematics, he tells us, has been a science, in the strict sense of the word, from time immemorial ; but he omits to tell us that pure mathematics, dealing solely with number and form, and not involving conceptions of force, could never have been in the theological stage. It was only the phenomena of force which to primitive men must have seemed to require an anthropomorphic explanation. The action of the human will, by the analogy of which external events were explained, may be a mechanical, but it is not a geometrical or algebraic phenomenon. When we come to mechanics, there is room to construct volitional explanations. Nevertheless in mechanics there are so few traces of such explanations, since the dawn of history, that Comte thinks it may have always been a positive science ; and he quotes approvingly Adam Smith's remark that nowhere do we ever hear of a god of Weight. 2 196 OOSMIG PHILOSOPHY. [^t- i- Sach a god, however, had there ever been one, would have been a generalized deity, belonging to a comparatively advanced system of polytheism ; and though we are entitled to infer from this that the earliest generalization of the phenomena of weight was a scientific and not a theological generalization, we are not entitled to infer that m the primeval fetishistic period, before the phenomena had been generalized at all, they were not supposed to be due to voli- tion. It is one of the unfortunate results of Comte's use of the term "theological," to characterize this primitive philosophy, that we are apt to think it necessary to seek for signs of a deity when examining the so-called theologic epoch. The idea of a god distinct from the phenomenon was, however, a polytheistic, not a fetishistic idea : it was the result of much abstraction and generalization. Fetish- ism endowed the particular object itself with volition. And, such being the case, I am inclined to believe that many even of the simplest mechanical phenomena may have been originally explained as due to the free will of the objects concerned.1 However this may be, there can be no doubt that mechanical conceptions ceased to be anthropo- morphic at a very early date, and that statics, one branch of mechanics, is the oldest of the sciences, outside of pure mathematics. If now we consider the three great branches of inorganic physics, we find abundant records of a time when the heavenly bodies were supposed to be intelligent creatures, and were worshipped as such. Even in the enlightened age of Perikles, and in the most advanced community then existing, Anaxagoras came near losing his life for asserting that the moon was a mass of rocks and not a goddess. Long after monotheism had overthrown these crude interpretations, the planets were still supposed to be the abode of controlling 1 See MytJis and Myth-Makers, chap, vii., "The Primeval Ghost World." CH. vui.] OBGANIZATION OF THE SCIENCES. 197 archangels. Even Kepler himself, early in the seventeenth century, was inclined to countenance this opinion, as may be seen from a remarkable passage in his " Harraonices Mundi " (p. 252). It was not until Newton that dynamical astronomy became a positive science. Similarly with the phenomena of terrestrial physics. The electric phenomena of storms, the thermal phenomena of congelation, the optical phenomena of the rainbow and the mirage, have, within the period known to history, been explained anthropomorphically ; and, as late as the time of Cardan, echoes were by the unlearned inter- preted as the voices of mocking demons, and ic/nes fatui were regarded as malign spirits inhabiting marshes. While in chemistry, both the Arabian alchemists and their European successors, in manipulating some of the more powerful re- agents, and especially in the use of explosive or highly com- bustible materials, beUeved themselves to be forcing unwilling supernatural agents to execute their purposes. Probably the name " spirits," as employed in modern pharmacy, has had some such anthropomorphic origin. Inorganic physics has by this time become almost entirely free from anthropomorphic conceptions. In the sciences which deal with organic phenomena, however, purely scientific conceptions do not yet reign supreme. Biology and sociology are still infected with metaphysical, and even to a certain extent with theological, notions. In biology, for instance, we have the anthropomorphic conception of an arcliceiis or vital principle, distinct from the organism, and controlling its molecular processes. Though such a theory would not, at the present day, be defended by any authoritative writer upon this subject, it is nevertheless vaguely present in the popular mind, and exerts a clandestine influence even upon scientific speculations. The metaphysical doctrine of stimulus, so ably criticized by Dr. Anstie in his treatise on " Stimulants and Narcotics," — the doctrine that stimulus is, not an increase in the rate of nutrition of the nerves, but a goading of the 198 COSMIC PHILOSOPHY. [pt. l organism, sure to be followed by a depressive reaction —is founded mainly upon this antiquated a priori conception of a vital principle. To take another instance, colds, fevers, and other diseases are commonly spoken of as entities which " get into the system," and are -to be driven out ; and imper- fectly educated physicians are often heard reasoning upon this mythological assumption ; whereas a disease of any kind, scientifically considered, is not an entity, but a disturbance of equilibrium among the interacting functions of the organism. A cancer, for instance, is a modification of struc- ture resulting from a disturbance in the general process of nutrition. Molecules which should normally be deposited here and there throughout the various tissues begin to aggre- gate over a single limited area, forming a new abnormal tissue, of low vitality; and this new tissue grows at the expense of the organism until death ensues from exhaustion, or, if the wall of a large bloodvessel happens to get en- croached upon and disintegrated, death ensues from hemor- rhage. So an ordinary fever, in which blood-poisoning does not occur, is the result of an iE-understood alteration in the molecular properties of the blood, one of the chief symptoms of which is the adherence of the blood-corpuscles to the walls of the capillaries. Yet so prevalent still is the personifying habit of thought, that cancers and fevers are spoken of and reasoned about as occult entities, as ugly Things which some- how or other " get into " the blood. It is hardly necessary to insist upon the prevalence of the metaphysical habit in sociology, where final causes are still sought after, where the doctrine of the " freedom of the will " (or, as it might better be termed, of the " lawlessness of voli- tion ") still maintains a precarious footing, and where prac- tical conclusions are constantly based upon the a pi'iori doctrine of inherent "rights." Here, too, as well as in biology, even the theological point of view not unfrequently appears. The late war between Trance and Germany was CH. VIII.] ORGANIZATION OP TEE SCIENCES. 199 doiibtless the occasion of many prayers to the " God of Battles." The same persons who, in the regular recurrence of the seasons, in the expansion of heated bodies, in the explosion of fulminating compounds, in the darkness caused by an eclipse, in short throughout the entire realm of in- organic phenomena, see nothing but the operations of uniform forces, nevertheless explain diseases, famines, and political revolutions, upon the hypothesis of an overruling Providence extraneous to the Cosmos ; announcing, perhaps, the doctrine of a divine jiidgment upon sin, — which is indeed not a fiction, but the mythologic version of a scientific truth. Not only (according to Comte) has deanthropomorphization proceeded more rapidly in the simpler sciences than in the more complex ones, but the generalization of causal agencies, of which deanthropomorphization is the result, took place earlier in the former than in the latter. This is to be seen by comparing the dates at which the sciences respectively ceased to be mere aggregations of empirical knowledge, and became founded as sciences, in the strict sense of the word. Thus astronomy, at least in its statical department, was a science in the days of Hipparchos. Physics became a science when Galileo discovered the law of falling bodies. Chemistry became a science, about a hundred and seventy years later, when Lavoisier overthrew the doctrine of phlogiston, and detected the true principles of combustion. Biology did not become a science until the very end of the eighteenth century, when Bichat pointed out the relations between the functions of organs and the properties of tissues. Finally sociology has hardly yet become a science ; and many educated persons still regard historical events as happening in no determinate sequence, and stigniatize, as not only chimerical but even impious, any attempt to formulate the order of such events. Here it becomes desirable to pass from simple exposition to criticism. In the Comtean views above set forth we must 200 COSMIC PHILOSOPHY. [pt. i. of course recognize a large amount of historic truth. There can be no doubt that anthropomorphic conceptions soonest disappear from those departments of science which are earliest constituted and most rapidly developed. Nor can there be any doubt that in a vague and general vi^ay the Comtean arrangement represents, or at any rate suggests, the historic order of progression. No doubt mathematics is the oldest of the sciences— as indeed its name curiously hints to us— and sociology the youngest. No doubt the movements of masses, of which astronomy and physics treat, were correctly formu- lated sooner than the combinations of heterogeneous mole- cules, which form the subject-matter of chemistry. And no doubt the science of inorganic phenomena as a whole is more complete than the science of organic phenomena. All this must be admitted. Yet if we examine more closely into the matter, we shall discover grave errors in this classification which looked so fair to us on a cursory inspection. We shall notice first that in many points of fundamental importance it does not faithfully represent the order of historic progres- sion ; and when we come to inquire into the reason of this failure, we shall find that the classification errs from its very simplicity, that tlie facts to be arranged are too com- plex and heterogeneous to admit of any such facile linear arrangement. In the first place the historical relations between astronomy and physics have been mis-stated by Comte, and he has marked out the province of physics after a fashion that is, at the present day, completely indefensible. To class together the science which treats of weight and pressure, and the sciences which treat of light, heat, and electricity, and to refer to the whole under the general appellation of Physics, is to prepare the way for statements which are too general to be accurate. In contrasting physics with astronomy, how- ever, Comte is careful to let us know that he intends to designate that phj'sics which deals with the phenomena of cii. viii.] ORGANIZATION OF THE SCIENCES. 201 moving masses; for he tells us that while astronomy has been a science since the time of Hipparchos, physics first became a science in the days of Galileo. The slightest con- sideration will show us that this apparent confirmation of Comte's views rests upon a verbal ambiguity. For what por- tion of astronomical phenomena had been generalized as early as the time of Hipparchos ? Simply the statical or geo- metrical portion, namely, the apparent motions of the planets, the great achievement of Hipparchos having been the con- struction of the theory of epicycles and eccentrics, whereby to formulate these motions. It is needless to add that all the geometrical data used in making this generalization had been obtained from the previous observation of terrestrial pheno- mena. And what portion of physics was it which was not generalized till the time of Galileo ? It was the dynamical portion, since statics had been erected into a science by Archimedes, who lived just a century before Hipparchos. By comparing the statical part of astronomy with the dyna- mical part of physics, Comte finds it quite easy to establish the precedence of the former. Unfortunately, such pre- cedence is not what the argument requires, though it is all that can be established. If we compare like orders of pheno- mena, we shall see at once that it was physics which pre- ceded astronomy. Dynamical astronomy became a science only with the discovery of the law of gravitation ; and this law was not discovered, nor could it have been discovered, until after the leading generalizations of terrestrial dynamics had been established. For, as Mr. Spencer observes, " What were the laws made use of by Newton in working out his grand discovery ? The law of falling bodies, disclosed by Galileo ; that of the composition of forces, also disclosed by Galileo ; and that of centrifugal force, found out by Huy- ghens — all of them generalizations of terrestrial physics. . . . Had M. Comte confined his attention to the things and dis- regarded the words, he would have seen that before mankind 202 COSMIC PHIL080PKY. [pt. i. scientifically coordinated amj one class of phenomena dis- played in the heavens, they had previously coordinated a parallel class of phenomena displayed upon the surface of the earth." ^ This criticism is a very incisive one. It destroys this part of Comte's classification not only from the historical, but also from the logical point of view. It shows that the study of astronomy depends upon that of terrestrial physics, and should therefore come after, and not before it. In fact the whole science of astronomy, as at present constituted, con- sists of two portions, — the theory of gravitation and the theory of nebular evolution. The first of these, as we have just seen, is a mere extension to celestial phenomena of cer- tain laws of terrestrial physics. The second depends upon the study of terrestrial phenomena in a yet greater degree, since it involves the knowledge not only of gravitation, but also of radiant heat, and of the conditions of equilibrium of gases and liquids.^ If now we compare physics with chemistry, we shall find a similar ambiguity in Comte's results. It is easy to say that chemistry was not organized into a science until toward the close of the eighteenth century, while physics was organized at the beginning of the seventeenth : but what do we now mean by physics ? If we mean merely the science which generalizes the phenomena of weight, our proposition is indisputable ; but unfortunately it is of little use in supporting the Comtean classification. For Comte, as we have seen, includes under the general head of physics, not 1 Spencer's Essays, 1st series, p. 179. * I leave this as it stood five years ago, when this chapter was written. The numerous and wonderful disclosures of spectrum-analysis, not only giving us unlooked-for information concerning the physical constitution of the stars, but even throwing new light on their movements, make it de.sirable, perhaps, to enlarge the scope assigned to astronomy in the text. But such a modifica- tion of the form of statement would show only the more forcibly how closely the study of astronomy depends on the study of terrestrial phenomena. The greatest step recently taken in science is thus an additional argument against the validity of Comte's conception. CH. riu.] ORGANIZATION OF THE SCIENCES. 203 only the science of weight, but also the sciences of heat, light, electricity and magnetism, to say nothing of sound. It was incumbent on Comte to show that this whole group of phenomena became scientifically coordinated at an earlier date than the phenomena of chemical composition and decomposition. This, however, it would have been impos- sible to show. Electric phenomena, the most backward of the group, were not scientifically coordinated until the close of the last century, when Coulomb generalized the laws of electric equilibrium. Strictly speaking, there ^as no general science of Physics even when Comte wrote the " Philosophie Positive ; " and in linking together the allied departments of optics, thermology, acoustics and electrology, he made up what was then an incongruous group, about which it was unsafe to make general statements. In 1842 — ■ the year in which Comte's work was finished — Mr. Grove, by showing that the different allied manifestations of physical force are modes of motion which are convertible into each other, laid the foundations of a general science of Molecular Physics, regarded as a science of vibrations. And in 1843 Mr. Joule, by discovering the mechanical equivalent of heat, gave to the new science a quantitative character. These were the great epoch-making steps, like the steps taken by Newton in astronomy, which founded the science. It is thus evident that Comte Avas far from successful in this part of his classification ; and considering the state of science forty years ago, it appears impossible that he should have succeeded. He united phenomena which should have been kept separate, and separated phenomena which should have been united. We are now in a position to see that Comte's grand division of inorganic science must be subdivided into Molar Physics, which' treats of the move- ments of masses ; Molecular Physics, which treats of the movements of molecules and of the laws of aggregation of homogeneous molecules ; and Chemistry, which treats of the 204 COSMIC PHILOSOPHY. [pt. i. laws of aggregation of lieterogeneous molecules. And we see, moreover, that astronomy is merely tlie application of the principles of molar physics (and, in its latest researches, of molecular physics and chemistry also) to the study of a special class of concrete phenomena. Such is the logical arrangement ; and the only historical parallelism to be found is the fact that theorems relating to masses were reached sooner than theorems relating to molecules. It would not be difiicult to cite other instances in which the Comtean classification is at variance not only with the order of the phenomena classified but also with the order of historic progression. But I prefer to quote from Mr. Spencer a remarkable passage which strikes immediately at the vital point of the theory. Comte's fundamental error was in not recognizing " the constant effect of progress in each class upon all other classes ; but only on the class succeeding it in his hierarchical scale. He leaves the impression that, with trifling exceptions, the sciences aid each other only in the order of their alleged succession. But in fact there has been a continuous helping of each division by all the others, and of all by each. Every particular class of inquirers has, as it were, secreted its own particular order of truths from the general mass of material which observation accumulates; and all other classes of inquirers have made use of these truths as fast as they were elaborated, with the effect of enabling them the better to elaborate each its own order of truths. It was thus with the application of Huyghens's optical discovery to astronomical observation by Galileo. It was thus with the application of the isochronism of the pendulum to the making of instruments for the measuring of intervals, astronomical and other. It was thus when the discovery that the refraction and dispersion of light did not follow the same law of variation, affected both astronomy and physiology by giving us achromatic telescopes and micro- scopes. It was thus when Bradley's discoveiy of the aberra- CH. vui.] ORGANIZATION OF THE SCIENCES. 205 tion of light enabled him to make the first step towards ascertaining the motions of the stars. It was thus when Cavendish's torsion-balance experiment determined the specific gravity of the earth, and so gave a datum for calculating the specific gravities of the sun and planets. It was thus when tables of atmospheric refraction enabled observers to write down the real places of the heavenly bodies instead of their apparent places. It was thus when the discovery of the different expansibilities of metals by heat, gave us the means of correcting our chronometrical measurements of astronomical periods. It was thus when the lines of the prismatic spectrum were used to distinguish the heavenly bodies that are of like nature with the sun from those which are not. It was thus when, as recently, an electro-telegraphic instrument was invented for the more accurate registration of meridional transits. It was thus when the difference in the rates of a clock at the equator and nearer the poles, gave data for calculating the oblateness of the earth, and accounting for the precession of the equinoxes. It was thus — but it is needless to continue. We have already named ten cases in which the single science of astronomy has owed its advance to sciences coming after it in Comte's series. Not only its secondary steps, but its greatest revolutions have been thus determined. Kepler could not have discovered his celebrated laws, had it not been for Tycho Brahe's accurate observations ; and it was only after some progress in physical and chemical science that the improved instruments with which those observations were made, became possible. The heliocentric theory of the solar system had to wait until the invention of the telescope before it could be finally established. Nay, even the grand discovery of all — the law of gravitation — depended for its proof upon an operation of physical science, the measurement of a degree upon the earth's surface. Now this constant intercommunion, here illustrated in the case of one science only, has been taking place with all the sciences 206 GOSMIG PHILOSOPHY. [pt. i. .... Let us look at a few cases. The theoretic law of the velocity of sound, enunciated by Newton on purely mecha- nical considerations, was found wrong by one-sixth. The error remained unaccounted for until the time of Laplace, who, suspecting that the heat disengaged by the compression of the undulating strata of the air, gave additional elasticity and so produced the difference, made the needful calculations and found he was right. Thus acoustics was arrested until thermology overtook and aided it. When Boyle and Mariotte had discovered the relation between the density of gases and the pressures they are subject to; and when it thus became possible to calculate the rate of decreasing density in the upper parts of the atmosphere ; it also became possible to make approximate tables of the atmospheric refraction of light. Thus optics, and with it astronomy, advanced with barology .... When Fourier had determined the laws of conduction of heat, and when the earth's temperature had been found to increase below the surface one degree in every forty yards, there were data for inferring the past condition of our globe ; the vast period it has taken it to cool down to its present state ; and the immense age of the solar system — a purely astronomical consideration. Chemistry having advanced sufficiently to supply the needful materials, and a physiological experiment having furnished the requisite hint, there came the discovery of galvanic electricity. Galvanism reacting on chemistry disclosed the metallic bases of the alkalies, and inaugurated the electro-chemical theory ; in the hands of Oersted and Ampk'e it led to the laws of magnetic action; and by its aid Faraday detected significant facts relative to the constitution of light. Brewster's discoveries respecting double refraction and dipolarization proved the essential truth of the classification of crystalline forms according to the number of axes, by showing that the molecular constitution depends upon the axes. In these, and in numerous other cases, the mutual influence of the sciences en. vili.] ORGANIZATION OF THE SCIENCES. 207 has been quite iuclependeut of any supposed hierarchical order. Often, too, their interactions are more complex than as thus instanced— involve more sciences than two .... So complete in recent days has become this consensus among the sciences, caused either by the natiu'al entanglement of their phenomena, or by analogies in the relations of their phenomena, that scarcely any considerable discovery con- cerning one- order of facts now takes place without very shortly leading to discoveries concerning other orders."^ Mr. Spencer goes on to describe the infinitely complex manner in which the various sciences act upon the advance- ment of the arts, and are reacted upon by that advancement. He enumerates the vast multitude of arts, involving the knowledge of many distinct sciences, which enter into the economical production of such an apparently simple article as a child's calico frock. He shows that the various sciences by turns stand in the relation of arts to each other ; and that often the mere process of observation in any one science requires the aid of half a dozen other sciences. But it is needless for me to go on quoting from an essay which is easily accessible, and which should be read from beginning to end by everyone who wishes to understand the true character of scientific progress. I prefer to add an illustra- tion or two, suggested by the progress of science during the nineteen years that have elapsed since that essay was published; and to observe how Kirchhoff's discoveries in spectrum-analysis — rendered possible only through a great advance in chemical knowledge — have reacted upon astronomy, enabling Mr. Huggins to determine the proper motion of Sirius, and consequently, by putting' it in our power to ascertain the motions of all those stars which, moving directly towards or away from us, yield no parallax, have laid the foundations for a general theory of sidereal dvnamics, to be further elaborated in the future. Or to take > Spencer's Essays, 1st series, pp. 181—183, 21i, 215. 208 COSMIC PHILOSOPHY. [i"f. i. a still more striking instance, let us remember how Adam Smith's elucidation of the principle of " division of lahour," in sociology, suggested to Goethe the conception of a " division of labour " in biology, and thus heralded Von Baer's magni- ficent discovery that organic development is a progressive change from homogeneity to heterogeneity of structure. And let us note how this discovery in biology has lately reacted upon all preceding departments of investigation, strengthening the nebular theory in astronomy and the theory of the pro- gressionists in geology ; and thus ultimately reacting upon our philosophy by giving us, for the first time, a scientific doctrine of the evolution of the physical universe. Enough has been alleged to prove that the Comtean view of the progress of science fails to account for more than a limited portion of the facts of that progress. Instead of the sciences aiding each other, with few and imimportant ex- ceptions, only in the hierarchical order in which Comte has placed them, we perceive that they have continually been aiding each other in all directions at once. The more complex sciences have all along been assisting the simpler ones, and these have often been delayed in their progress for want of the assistance which the former have ultimately furnished. There has, therefore, been no such thing as a progressive evolution of the sciences in a linear order ; but there has been a consentaneous evolution, in which the advance of each science has been a necessary condition of the advance of all the others. It thus appears that Comte unduly simplified the problem. His classification well enough expresses the order of develop- ment of the sciences, in so far as their development has depended merely on the relative simplicity or complexity of the phenomena with which they have had to deal. It rests upon the assumption that, with few and unimportant ex- ceptions, the progress of generalization has been from the simple to the complex. Now this is not the case. The OH. vni.] ORGANIZATION OF THIS SCIENCES. - SOP progress of generalization has indeed been partly determined by the relative simplicity or complexity of the phenomena to be generalized (and this fact accounts for the considerable amount of truth which the Comtean doctrine contains) ; but it has been also determined by several other circumstances. In the chapter on " Laws in General " to be found in the first edition of " First Principles," but omitted in the revised edition, Mr. Spencer lias called attention to some of these circumstances. He reminds us that not only are phenomena early generalized in proportion as they are simple, but also in proportion as they are conspicuous or obtrusive. " Hence it happened that after the establishment of those very manifest sequences constituting a lunation, and those less manifest ones marking a year, and those still less manifest ones marking the planetary periods, astronomy occupied itself with such inconspicuous sequences as those displayed in the repeating cycle of lunar eclipses, and those which suggested the theory of epicycles and eccentrics ; while modern astro- nomy deals with still more inconspicuous sequences, some of which, as the planetary rotations, are nevertheless the simplest which the heavens present." The solution of the problem of specific gravity by Archimedes, and the discovery of atmospheric pressure, nearly nineteen hundred years later, by TorricelU, involved mechanical relations of exactly the same kind ; but the connection between antecedent and con- sequent was much more conspicuous in the former case than in the latter. The effect produced by the air in decomposing soil is a phenomenon just as simple as the rusting of iron or the burning of wood ; but it is far less conspicuous, and accordingly chemistry generalized the one long before the other. Finally, if, remembering the enormous advance in science due to the telescope and microscope, and bearing in mind the equally astonishing results which are likely to arise from the use of the lately-invented spectroscope, we ask what is the character of the service rendered us by these VOL. I. P 210 COSMIC PHILOSOPHY. [tt. i. instruments ; the reply is that they enable us to generalize phenomena which before were too inconspicuous to be generalized. Again, other things equal, phenomena that are frequent have been scientifically explained sooner than unusual phe- nomena. " Eainbows and comets do not differ greatly in conspicuousness, and a rainbow is intrinsically the more involved phenomenon ; but chiefly because of their far greater commonness, rainbows were perceived to have a direct dependence on sun and rain while yet comets were regarded as supernatural appearances." In like manner, the more concrete relations have been formulated before those that are more abstract. If we were to adhere rigorously to Comte's principle of decreasing generality, we should have to place the infinitesimal calculus before algebra, and algebra before arithmetic. But the order of development has been just the reverse,— from arithmetic, the least abstract department, to calculus, the most abstract. Lastly I would suggest a circumstance, not mentioned by Mr. Spencer, namely that, other things equal, the sciences must advance according to the ratio between the complexity of the phenomena with which they deal and the multiplicity of our means for investigating those phenomena. I shall presently describe our three chief implements for extorting the secrets of Nature — observation, experiment and com- parison ; showing that in general, as phenomena become more and more complicated, our ability to make use of these implements increases. In astronomy we have only observa- tion to help us; but astronomic phenomena are comparatively simple, so that here we have a highly-developed science. In biology we can use all three implements ; and so, in spite of the complexity of vital phenomena, we have here a tolerably well-organized science. But in meteorology, we have to deal with very complex phenomena, and still have no resource save in steadfast observation. Hence meteorology is still a CH. VIII.] ORGANIZATION OF THE f^OIENCES. 211 very backward science, — more backward even than sociology, of which the phenomena are far more complex. According to Mr. Spencer, phenomena are also generalized early in proportion as they directly affect human welfare. But this circumstance would appear to have far less potency than the others above enumerated. There is, of course, no doubt that men will earliest study those subjects which most obviously concern them ; but whether their study will be fruitful or not depends, as it seems to me, upon the other factors in the case, above enumerated. I doubt if there is any instance in which this factor has actually overruled the other factors, as these have continually overruled each other Sociology is the science which, more than all others, would seem to have direct practical bearings upon human welfare ; yet, although men have studied social phenomena since the days of Plato, they have but lately arrived at any scientific generalizations concerning them. The daily changes of weather are more obviously concerned with human interests than the geological succession of extinct animals and vege- tables ; yet our scientific knowledge of palseontology, though unsatisfactory enough, is yet far more advanced than our scientific knowledge of meteorology. No doubt men wiU. soonest endeavour to understand the phenomena which most intimately concern them ; but the order in which they will come to understand them wiU depend upon the simplicity, the concreteness, the conspicuousness, and the frequency of the phenomena, and upon the number and perfection of the implements of investigation which are at command. Indeed, from one point of view, it may be urged that direct com- plicity with human interests is often a hindrance to the scientific investigation of phenomena. Doubtless the dis- interested calmness with which remote mathematical and physical inquiries are prosecuted is one secret of their success. As Hobbes remarked, with keen sarcasm, "even the axioms of geometry would be disputed if men's passions p 2 212 COSMIC PHILOSOPHY. [pt. i. were concerned with them." And does not daily experience teach us the difficulty of getting our legislators to accept the simplest and most completely established principles of political economy ? Thus there are at least five separate factors determining the order and rate at which knowledge progresses ; and it is the interaction of these factors which has made the actual order of scientific development too complex to be embraced in any linear formula, like that proposed by Comte. It is because it recognizes only one of these factors that the Comtean classification fails to represent the historic order in its true complexity. It makes a straight line where it ought to make a system of inosculating spirals. Eeturning now from the historical to the logical point of view, we have to note a still more fundamental error in the Comtean classification. That classification rests primarily upon the distinction, above explained, between the abstract and the concrete sciences. That there is such a distinction cannot be qtiestioned ; but it will not be difficult to show that Comte has made the division incorrectly. When Comte contrasts chemistry with mineralogy, because the one formulates the abstract laws of the aggregation of hetero- geneous molecules, while the other applies these laws to concrete instances actually realized in nature, under the influence of particular sets of conditions, — the distinction must be admitted as valid. But when he similarly contrasts biology with zoology and botany, because the one formulates the general laws of life, while the others merely study the conditions of existence of particular genera and species, the distinction cannot be admitted as valid. In so far as zoology and botany are restricted to the mere description and enumeration of organic forms, they cannot strictly be called sciences at all, but only branches of natural history. In so far as they are anything more than this, they are a consti- tuent part of biology. For in biology, it is the study of the CH. VIII.] OliGANIZATION OP THE SCIENCES. 213 concrete conditions of existence of living organisms which lies at the bottom of the whole. The laws of nutrition, reproduction and innervation are not abstract laws, con- sidered apart from the conditions in which they are realized, like the law of inertia in physics, or the law of definite proportions in chemistry. They are realized in each concrete instance just as much as certain chemical and physical laws are realized in each concrete instance of mineralogy. Or, in other words, the laws of biology are derivative uniformities, while the laws of physics and chemistry are original unifor- mities. Given the general laws of molecular combination and decombination, and given also a certain definite organiza- tion placed in a given environment, and the laws of nutrition, reproduction and innervation follow. Take away the definite organization, and you have nothing left but the laws of molecular rearrangement, which are the subjects of physics and chemistry. This is not identifying biology with physics and chemistry. The fact of organization remains, by the study of which biology is an independent science. But it is a concrete science, since it can study organization only as actually exemplified in particular organisms. The same is true of sociology, which is simply an extension of the principles of biology and psychology to the complex phenomena furnished by the mutual reactions of intelligent organisms upon each other. There is no abstract science of sociology which leaves out of sight the special complications arising from the interaction of concrete, actually-existiug communities. Any such abstract science is a mere figment of the imagination, born of Comte's excessive passion for systematizing. The science of sociology is the generalization of the concrete phenomena of society, as recorded in history ; and, in the widest sense, the laws of sociology are the laws of history. And, travelling back to the other end of the series, a similar criticism must be made upon astronomy. This science is an application of molar physics (and latterly. 214 COSMIC PHILOSOPHY. [ft. i. in some degree, of molecular physics and chemistry) to the concrete phenomena presented by the heavenly bodies. The universal law of gravitation is indeed an abstract law ; it formulates a property of bodies. But it holds good of terrestrial as well as of celestial phenomena : and its applica- tion to either class of phenomena, in their actual compli- cations, constitutes a concrete science. These are the considerations which irretrievably demolish the Comtean classification, considered as an expression of the true relations between the sciences. It appears that Comte has intermingled three abstract sciences, — mathematics, physics, and chemistry, — with three concrete sciences, — astronomy, biology, and sociology. He was led into this confusion by confounding the general with the abstract. But, as Mr. Spencer has pointed out, these terms have different meanings. "Abstractness means detachment from the incidents of particular cases ; generality means manifestation in numerous cases. On the one hand the essential nature of some phenomenon is considered, apart from the pheno- mena which disguise it. On the other hand, the frequency of recurrence of the phenomenon, with or without various disguising phenomena, is the thing considered. An abstract truth is rarely if ever realized to perception in any one case of which it is asserted. A general truth may be realized to perception in all of the cases of which it is asserted. . . . In other words, a general truth colligates a number of parti- cular truths ; while an abstract truth colligates no particular truths, but formulates a truth which certain phenomena aU involve, though it may be actually seen in none of them." ^ Now there can be no question that if we were to substitute the words general and special for the words abstract and concrete, in the Comtean classification, that classification would express, to a certain extent, a true distinction. No doubt chemistry and biology are general sciences, while ^ Spencer, Classification of the Sciences, 1864, pp. 7 — 9. CH. TIII.J ORGANIZATION OF THE SCIENCES. 215 mineralogy, zoology and botany are more or less special sciences. But the distinction between abstract and concrete is by far the deeper distinction, and because the Comtean classification incorrectly formulates it, there is no alternative but to regard that classification as incurably faulty. The above criticism, however, supplies us with materials for making a better one. As the case now stands, we have three abstract sciences, — mathematics, physics, and chemistry. Yet a distinction in degree of abstractness arises between mathematics and the other two. All three were originally obtained by generalization from concrete phenomena. All mathematical analysis starts from numeration, as all geometry starts from measuring. Nevertheless, mathematics has utterly outgrown the processes of concrete observation, and is a purely deductive science, dealing merely with number and figure, or what may be called the blank forms of pheno- mena. It thus becomes more nearly allied to logic than to the physical sciences ; and indeed the chief difference between the two is that logic deals with qualitative relations only, while mathematics deals with relations that are quanti- tative. On the other hand, molar physics, molecular physics, and chemistry, dealing with abstract laws of motion and force that are gained from experience of concrete phenomena, and appealing at every step to the concrete processes of observation and experiment, may be distinguished as abstract- concrete sciences. These sciences analyze concrete pheno- mena, in order to formulate the working of their factors. " In .every case it is the aim to decompose the phenomenon, and formulate its components apart from one another; or some two or three apart from the rest." The problem is to ascertain the laws of molar motion, or molecular vibration, or atomic rearrangement, not as these laws are actually realized to perception in any concrete example, "but as they would be displayed in the absence of those minute interferences which 218 COSMIC PHILOSOPHY. [pt. i. history and formulate the modes of action of actually exist- ing aggregates, from the time when they begin to exist as aggregates down to the time when they cease to exist as aggregates. It is quite otherwise with the abstract-concrete sciences. By aU. these sciences, actually existing aggregates are im- plicitly ignored ; " and a property, or a connected set of pro- perties, exclusively occupies attention." It matters not to Molar Physics " whether the moving mass it considers is a planet or molecule, a dead stick thrown into the river or the living dog that leaps after it : in any case the curve described by the moving mass conforms to the same laws." So when Molecular Physics investigates " the relation between the changing bulk of matter and the changing quantity of mole- cular motion it contains,'' constant account is taken of con- nected sets of properties, but no account whatever is taken of particular aggregates of matter. The conclusions reached apply equally to Chimborazo and to a tea-kettle, to the solidification of the earth's crust and to the cracking of a pipe by frozen water. Similarly in Chemistry, while " ascer- taining the af&nities and atomic equivalence of carbon, the chemist has nothing to do with any aggregate. He deals with carbon in the abstract, as something considered apart from quantity, form, or appearance, or temporary state of combination ; and conceives it as the possessor of powers or properties, whence the special phenomena he describes result ; the ascertaining of all these powers or properties being his sole aim." So that, from first to last, the object of the abstract-concrete sciences is to give an account " of some order of properties, general or special ; not caring about the other traits of an aggregate displaying them, and not recog- nizing aggregates at all further than is implied by discussion of the particular order of properties." Finally, the abstract sciences deal solely with relations among aggregates or among properties, or with the relations CH. VIII.] ORGANIZATION OF THE SCIENCES. 219 between aggregates and properties, or with relations among relations ; but take no further account of aggregates or of properties than is implied in the discussion of a particular order of relations. For example, " the same Logical formula applies equally well, whether its terms are men and their deaths, crystals and their planes of cleavage, or letters and their sounds. And how entirely Mathematics concerns itself with relations, we see on remembering that it has just the same expression for the characters of an infinitesimal tri- angle, as for those of the triangle which has Sirius for its apex and the diameter of the earth's orbit for its base." i Since then, " these three groups of sciences are, respec- tively, accounts of aggregates, accounts of properties, accounts of relations, it is manifest that the divisions between them are not simply perfectly clear, but that the chasms between them are absolute." Thus we arrive at the following Olassification of the Sciences. Absteaot Soibnobs, dealing with relations, that are Absteact-Conoeetb Sciences, dealing with properties, that are manifested Concrete Sciences, dealing with aggregates (with their properties and rela- tions), as actually exempli- fied qualitative ; quantitative ; Vin movements of mass- | es; ( in movements of mole- cules ; and in aggrega- I tions of molecules that | are homogeneous ; in aggregations of mole- 1 cules that are hetero- \ geneous ; ] /in stellar and planetary systems ; j in the earth ; in living organisms ; in the functions which ' adjust organic actions ( to specific relations in \ the environment ; in the mutual relations ' of living organisms ( grouped into commu- | nities ; Logic. Mathematics. Molar Physics. Molecular Physics. Chemistry. Astronomy. Geology. Biology. Psychology. Sociology. 1 Spencer, Recent Discussions, pp. 107 — 110. 220 COSMIC PHILOSOPHY. [pt. i. ' It remains to add that each of the five concrete sciences may, for the purposes of our philosophic synthesis, be advan- tageously regarded as consisting of two portions. In the first place, we have Astronomy — in the time-honoured sense of the word — which deals with the motions of stellar and planetary masses in their present state of moving equili- brium ; and Astrogeny, as it is now frequently termed, which seeks to ascertain the genesis of these masses and of their motions. Geology admits of a similar division. The general laws of the redistribution of gases and liquids over the earth's sur- face, which we commonly call meteorology, and the general laws of the formation of solid compounds, which we call mineralogy, unite to furnish us with a general doctrine of the massive and molecular motions going on at any given epoch and under any given geographic condition of the earth's sur- face. But geology has another clearly-defined province ; which is to formulate the general order of sequence among terrestrial epochs ; to ascertain the genesis of the various molar and molecular redistributions going on at any given period, by regarding them as consequent upon the relations between a cooling rotating spheroid and a neighbouring sun which imparts to it thermal, luminous, and actinic undula- tions. This part of the science is already currently known as Geogeny. And here we touch upon the essential point of difference between geology and astronomy, regarded as sciences of development, which it seems to me that M. Wyrouboff, in his interesting essay upon this subject, has quite lost sight of. Both astrogeny and geogeny are con- cerned with the phenomena presented by a cooling and con- tracting body, of the figure known as a spheroid of rotation. In the one case this body is the sun, which once more than filled the orbit of Neptune ; in the other case it is the earth, which at first more than filled the moon's orbit. But together with this point of community between the two sciences, there CH. VIII.] OROANIZATJON OF THE SCIENCES. ?21 is a fundamental difference between, them. "While astrogeny contemplates the contracting spheroid chiefly as a generator of other spheroids, which are from time to time formed from its equatorial belt, detached as often as the centrifugal force at its equator begins to exceed the force of gravitation at the same place; on the other hand, geogeny contemplates the contracting spheroid only with reference to the redistributions of matter and motion going on within itself, and partly con- sequent upon its cooling. Partly consequent, I say, for there is one further point of difference between the two sciences. Astrogeny contemplates its spheroid as a radiator of heat, but neglects, as not affecting its own peculiar problems, the heat which the spheroid may receive by radiation from other masses. But geogeny not only studies its spheroid as a radiator of heat, but includes, as of the highest importance, the heat which it receives from an external source. In Biology also the twofold point of view is obvious, according as we study structures and functions in mobile equilibrium at any particular epoch, or on the other hand the process of adaptation which structures and functions undergo as the conditions of existence change from epoch to epoch. The first of these studies gives rise to the sciences of anatomy and physiology, as well as to the subsidiary science of patho- logy. On the other hand Biogeny comprises embryology, morphology, and questions relating to the origin of species. Psychology too admits of a similar division, into the depart- ment which embraces the laws of association, as generalized by James Mill and further illustrated by Mr. Bain; and Psychogeny, which endeavours to interpret the genesis of intellectual faculties and emotional feelings in the race, and their slow modifications throughout countless gene- rations. Finally in Sociology this principle of twofold division is so manifest that for the past thirty years the distinction has been currently, though too vaguely, drawn between " social 222 COSMIC PHILOSOPHY. [pt. i. statics " and " social dynamics." Obviously we may either study the phenomena arising from social aggregation, as they are manifested under any given set of conditions ; or we may study the phenomena of progress manifested in the relations of each epoch to preceding and succeeding epochs. In the first case, we have the sub-sciences of political economy, ethics, jurisprudence, etc. ; in the second case we have Sociogeny, or the so-called " science of history." In each of the five concrete sciences, therefore, there is a sub-science which deals with the genesis or evolution of the phenomena which form the subject-matter of the science ; and it is with these sciences of genesis that we shall chiefly be concerned throughout the second part of this work. It is of little consequence, however, whether the symmetrical nomenclatrure here used be adopted or not. Excessive sym- metry in naming is a mark of pedantry rather than of accu- racy; and questions of terminology become important only when differences of opinion are involved. In reasoning about the Test of Truth, it makes a great difference whether we use the term " incredible " or the term " inconceivable." In the present discussion, it makes a great difference whether we speak of biology as an " abstract " or as a " concrete " science. But provided we bear in mind the twofold character of the problems which it is the oiiice of biology to solve, it makes little difference whether or not we employ such a term as " biogeny " ; and such expressions will be used, in the present work, only when it is desirable to avoid tedious circumlocution. If now we proceed to inquire whether our revised classifi- cation can be made to afford us a bird's-eye view of the historic progression of the respective sciences, we shall find that it cannot be made to do so. The classification has been made upon purely logical grounds ; and no attempt has been njade to express the order of historic progression, simply because, as I have already shown, that order cannot be ex- CH. VIII.] ORGANIZATION OF THE SCIENCES. 223 pressed by any linear series. If we were to represent the respective rates of progress in the different sciences by a device familiar to statisticians ; denoting the sciences by a series of curves, starting from the same point, and constructed with reference to a common abscissa ; marking off the abscissa into equal sections and sub-sections answering to centuries and decades ; and expressing the progress of each science at each decade by the length of the ordinate erected at the cor- responding sub-section ; we should see these curves from first to last intersecting each other in the most complicated and apparently capricious manner. Probably the only conspi- cuously persistent relation would be that between the entire set of curves representing the concrete organic sciences, and all the rest of the curves taken together ; of which two sets the former would, on the whole, have the shorter ordinates. But on sufficiently close inspection, we should detect, between the sets of curves representing the abstract, the abstract-concrete, and the concrete sciences, a relation equally constant, and far more interesting, though less conspicuous. We should observe that all along the progress of the concrete sciences has determined that of the abstract-concrete and abstract sciences, and has been determined by it ; that, from first to last, synthesis and analysis have gone hand in hand. Such has been the complex order of progression. Men have begun by grouping concrete phenomena empirically. When the groups have become wide enough to allow the disclosure of some mode of force uniformly manifested in them, the operations of this force have begun to be experimentally or deductively studied, all disturbing conditions being as far as possible eliminated or left out of the account ; and thus have arisen the analytic or abstract-concrete sciences. And finally, as fast as the laws of the various manifestations of force have been generalized, the synthetical interpretation of phenomena has advanced by the aid of the knowledge of these laws. As Mr. Spencer well expresses it : " there has 224 COSMIC PHILOSOPBY. [pt. i. all along been higher specialization, that there might be a larger generalization ; and a deeper analysis, that there might be a better synthesis. Each larger generalization has lifted sundry specializations still higher; and each better synthesis has prepared the way for still deeper analysis." Long before Archimedes founded statics, the earliest branch of abstract- concrete science, empirical generalizations had been made in every one of the concrete sciences. Astronomy had accomplished the preliminary task of classifying stars according to their times of rising and setting, of tracing the apparent courses of the planets, of determining the order of recurrence of lunar eclipses, and of constructing chronological cycles. In geo- logy some scanty progress had been made, in classifying the physical features of the earth's surface, and in ascertaining the properties of a limited number of minerals. In biology, classification had been carried sufficiently far to enable an acute observer, like Aristotle, to distinguish between the ■selachians, or shark-tribe, and the bony fishes ; and a con- siderable amount of anatomical and physiological know- ledge had been acquired, as may be seen in the works of Hippokrates. Even in psychology there had been made a crude classification of the intellectual and emotional func- tions ; and the " Politics " of Aristotle show us the statical division of sociology already empirically organized. To such a point had the synthetic concrete sciences arrived in antiquity ; and this point they did not pass until the analytic abstract-concrete sciences had furnished them with factors with which to work. Astronomy must still remain in the empirical stage until molar physics had generalized the abstract laws of falling bodies, of the composition of forces, and of tangential momentum. Geology could not advance until molecular physics had supplied the general principles of thermal radiation and conduction, of evaporation and pre- cipitation, condensation and rarefaction. Biology was obliged to wait until chemistry had thrown light upon the molecular CH. viii.] ORGANIZATION OF THE SCIENCES. 225 constitution of the various tissues and anatomical elements, and had furnished the means of explaining synthetically such organic processes as digestion and assimilation. But, as we have already seen, the obligation has not been all on one side. The services rendered by the analytic to the syn- thetic sciences have been all along repaid by services no less essential. Thus the great principle of molar physics — the law of gravitation — could not be generalized from terrestrial phenomena alone, but had to wait until astronomic observa- tions had revealed the true forms of the planetary orbits and the rates of their velocities. Thus molecular physics has received important hints from mineralogy, the properties of crystals having rendered indispensable aid in the discoveries of polarization and double refraction, and therefore in the final verification of the undulatory theory. And thus also in late years the researches of Dumas, Laurent, Gerhardt, and Wil- liamson on the structure of organic molecules have reacted upon the whole domain of inorganic chemistry, regenerating the doctrine of types, supplying the fundamental conceptions of atomicity and quanti valence, replacing the dualistic theory of Berzelius by the theory of saturation and substitution, and inaugurating a radical revolution in chemical nomenclature. I may note in passing that this great revolution, which has rendered the science of only half-a-generation ago com- pletely antiquated, and has obliged so many of us to unlearn the chemistry which we learned at college, furnishes a crucial disproof of the Comtean theory of the way in which a scientific revolution should occur. We see that the chemistry of inorganic bodies was not placed upon its true foundation until the study of organic chemistry had supplied to the whole science its fundamental principles ; in spite of Comte, who always scouted at organic chemistry as an illegitimate science, and predicted the speedy extension of the dualistic theory to organic compounds. Space permitting, I might go on and point out more VOL. I. Q 226 COSMIC PHILOSOPHY. [ft. i. minutely how the allied sciences in each grand division have continually reacted upon each other; how synthesis has directly aided synthesis, and how analysis has directly aided analysis ; how the analytic and the simpler synthetic sciences have from time to time furnished new hints to mathematics ; and how all the other sciences, in all the divisions, from mathematics to sociology, have aided the progress of logic, supplying it with new methods of investigation and fresh canons of proof. But such a detailed survey is not needful for the purposes of this work. Let us rather return for a moment to our criticism of Comte, and, having already examined his organization of the sciences both from the historical and from the logical point of view, let us endeavour to render an impartial verdict as to the philosophic value of his achievement. If tried by its conformity to the ideal standard of perfec- tion furnished by the scientific and philosophical knowledge of the present day, the Comtean classification of the sciences must undoubtedly be pronounced, in nearly all essential respects, a failure. As a representation of the historic order of progression among the different sciences, it must be regarded as the imperfect expression of an inadequately comprehended set of truths. We have seen that this order of progression depends upon at least five interacting factors ; upon the simplicity, the concreteness, the conspicuousness, and the frequency of the phenomena investigated, and upon the comparative number and perfection of the implements of investigation. Of these five factors, the Comtean series takes into aecoant only the first, or at the utmost only the first and the last. For this reason it unduly simplifies the order of progression. Doubtless it is correct to say that, other things equal, the simpler and more general phenomena have been interpreted earlier than the more complex and special phenomena ; but the other things have not been equal. And consequently scientific evolution has not proceeded uniformly. CH. viii.J ORGANIZATION OF THE SCIENCES. 227 in a straight line, but rhythmically, in a plexus of curved lines. As a representation of the logical order of subordination among the different sciences, the Comtean series is equally faulty. While it correctly formulates sundry of the minor relations of dependence, as well as one relation of great im- portance, — that of the dependence of organic upon inorganic science, — it incorrectly formulates the grand distinction of all, — the distinction between abstract and concrete, between analytic and synthetic, science. It mixes together sciences formed by the analysis and synthesis of concrete pheno- mena, and a science which is purely abstract. It strives to represent, by a linear series, relations which are so complex that they can be adequately represented only in space of three dimensions. It is therefore indisputable that the Comtean classification, viewed absolutely, is a failure. The advance of science has refuted instead of confirming it. It has become rather an encumbrance than a help to the understanding of the true relations among the sciences. Shall we then, with Prof Huxley, say that the classification, and with it the whole Comtean philosophy of science, is " absolutely worthless ? " ^ I think not. "We might say as much of Oken or Hegel, but hardly of Stewart or Ampere ; far less of Comte. Mr. Spencer speaks more justly of his great antagonist when he nays : " Let it by no means be supposed from all I have said, that I do not regard M. Comte's speculations as of great value. True or untrue, his system as a whole has doubtless produced important and salutary revolutions of thought in many minds ; and will doubtless do so in many more. Doubtless, too, not a few of those who dissent from his general views have been healthfully stimulated by the con- sideration of them. The presentation of scientific knoiuledge and method as a ivhule, whether rightly or ivrongly coordinated, ' Huxley, Lay Sermons, p. 172. Q 2 228 COSMIC PHILOSOPHY. [pt. i. cannot Jiave failed greatly to widen the conceptions of most of his traders. And he has done especial service by familiariz- ing men with the idea of a social science based on the other sciences. Beyond which benefits resulting from the general character and scope of his philosophy, I believe that there are scattered through his pages many large ideas that are valuable not only as stimuli, but for their actual truth." This passage comes so near to appreciating Comte's true philosophic position, that one is surprised to find Mr. Spencer, after all, stating that position inadequately. Though he sees clearly that, whether rightly or wrongly coordinated, the presentation of scientific knowledge and method as a whole, must greatly have widened people's conceptions ; he does not explicitly recognize that this presentation of scientific knowledge and method as a whole was, in spite of the wrong coordination, a step sufficient of itself to change and renovate the entire attitude of philosophy. He tells us that persons like Prof Huxley, Prof. Tyndall, and himself, stand sub- stantially in the same position in which they would have stood had Comte never written ; that, " declining his re- organization of scientific doctrine, they possess this scientific doctrine in its pre-existing state, as the common heritage bequeathed by the past to the present." And elsewhere he tells us that Comte " designated by the term ' Positive Philosophy ' all that definitely-established knowledge which men of science have been gradually organizing into a coherent body of doctrine." It seems to me, on the other hand, that the coherent body of doctrine was the very thing which no scientific thinker had ever so much as attempted to construct, though Bacon, no doubt, foresaw the necessity of some such construction. M. Littr^ may well inquire what is meant by the great scientific minds whose traditions Comte is said to have followed. " Does it mean the philosophers ? Why, they have one and all belonged to theology or metaphysics, and it is not their tradition which Comte has followed. Does CH. viii.] ORGANIZATION OF THE SOmNGES. 229 it mean those who have illustrated particular sciences ? WeU, since they have not philosophized, Comte can hardly have received his philosophy from them. That which is recent in the Positive Philosophy, that which is Comte's invention, is the conception and construction of a philosophy, by drawing from particular sciences, and from the teaching of great scientific minds, such groups of truths as could be coordinated on the positive method." That the mode in which Comte effected this coordination was imperfect, may affect our estimate of the amount of his achievements, but it cannot affect our estimate of their character. The former is a merely personal question, in- teresting chiefly to disciples ; the latter is a general question, interesting to all of us who are students of philosophy. For the purposes of impartial criticism, the great point is, not that the attempt was a complete success, but that the attempt was made. When knowledge is advancing with such giant strides as at present, it is hardly possible to construct a general doctrine which forty years of further inquiry and criticism will not considerably modify and partially invali- date. It is now forty years since Comte framed his philo- sophy of science ; and during that period there is not a single department of knowledge, outside of pure mathematics, which has not undergone a veritable revolution. Molecular physics has been revolutionized by the discovery of the correlation of forces ; and the deduction of that principle, as well as of the principle of virtual velocities, from tlie law of the persistence of force, has placed molar physics also upon a new basis. Chemistry, as we have seen, has undergone changes nearly as sweeping as those brought about by Lavoisier; changes which have thoroughly renovated our conceptions of the phenomenal constitution of matter. Sidereal astronomy has been brought into existence as a science ; and we have learned how to make a ray of light, journeying toward us from the remotest regions of space. 230 COSMIC PHILOSOPHY. [ft. i. tell us of the molecular constitution of the matter from which it started. Geology has been robbed of its cataclysms, and periods of universal extinction; while both astrogeny and geogeny have assumed a new character through the wide extension of the theory of nebular genesis. There is not a truth in biology which has not been shown up in a new light by the victory of the cell-doctrine ; the discovery of natural selection has entirely remodelled our conceptions of organic development; and the dynamical theory of stimulus has wrought great changes, which are but the beginning of greater changes, in pathology, in hygiene, and in the treat- ment of disease. Psychology, in both its branches, has received a scientific constitution by the establishment of the primary laws of association, and the fundamental law of the growth of intelligence. And sociology, both statical and dynamical, has undergone changes equally important, as we shall see when we come to treat specially of that subject. ^11 this makes up an aggregate of scientific achievement such as the world has never before witnessed in anything like an equally short interval. So enormous is the accumu- lated effect of all these discoveries upon the general habits of thought, that the men of the present day who have fully kept pace with the scientific movement, are separated from the men whose education ended in 1830, by an immeasurably wider gulf than has ever before divided one progressive generation of men from their predecessors. And when we add that both the history of science and the general principles upon which discoveries are made have been, during this interval and largely through the impulse given by Comte himself, more thoroughly studied than ever before, — we may begin to realize how far the resources which we possess for constructing a synthesis of the sciences, exceed the resources which were at his disposal. We shall realize that Comte — at least where physical science is concerned — has come to be almost an ancient ; and we shall see that there may easily be CH. vHi.] OROANIZATION OF THE SCIENCES. 231 injustice in criticizing him as if he were a contemporary. We shall find the legitimate ground for wonder to be, not that he did so little, but that he did so much. And estimating him, as we estimate Bacon, from a purely historical point of view, we shall feel obliged to admit that the grand character- istic of the modern movement in philosophy — the continuous organization of scientific truths into a coherent body of doctrine — found in Comte its earliest, though by no means an adequate, exponent. Previous to him, as M. Littrd is right in reminding us, the field of general speculation belonged to metaphysics or theology, while science dealt only with specialities. It was owing to an impulse of which Comte is the earliest representative, that the tables were turned. The field of general speculation is now the property of science, while metaphysics and theology are presented as particular transitory phases of human thought.^ Whatever, therefore, may be the case with Mr. Spencer — whose entire originality cannot for a moment be questioned — it is not true of the great body of scientific thinkers, that they stand in essentially the same position in which they would have stood had Comte never written. The course of speculative inquiry during the past forty years would no more have been what it is, without Comte, than the course of speculative inquiry during the past two centuries would have been what it is, without Bacon. And, indeed, in Mr. Spencer's own case, — as he is himself disposed to admit, — there are several instances in which his very antagonism to Comte has led him to state certain important truths more clearly and more definitely than he would otherwise have been likelj^ to state them. The theory of deanthropomorphization, set forth in the preceding chapter, was presented in a much more vivid light than would have been possible had it not been reached through an adverse criticism of the Comtean doctrine of the "Three Stages." The condemnation of Atheism, ' Littre, Aiiguste Comte, p. 99. 232 COSMIC PHILOSOPHY. [pt. i. involved iu our statement of that theory, is redoubled in emphasis when Positivism is by the same reasoning con- denmed ; and our dissent from Hume is all the more strongly accented, when it is seen to be so complete as to include dissent from Comte also. So, too, the conclusions reached in the present chapter concerning the organization of tlie sciences are undeniably far more precise and satisfactory than they would have been if presented without reference to the earlier and necessarily cruder views of Comte. Indeed, in the very sense of incompleteness which would justly have attached itself to our exposition, had no mention been made of the Comtean theory, we may find fresh illustration of the fact that the errors of great minds are often no less instructive than the permanent truths which they liave vSucceeded in detecting. And consequently, so far from decrying the Positive Philosophy or seeking to ignore it, we shall much better fulfil our duty as critics if we frankly acknowledge that the speculative progress of the nineteenth century would have been incomplete without it. Holding these views, and for these reasons, we may freely admit the justice of much that Prof Huxley urges against _Comte; that his rejection of psychology was unphilosophical, and his acceptance of phrenology puerile ; that his acquaintance with science was bookish and unpractical, and that his efforts to found a social polity were the very madness of Utopian speculation. Plad he committed twice as many such blunders, his general conception of philosophy and his con- tributions to the logic of science would have remained substantially unaffected in value. Had Bacon enrolled him- self among the followers of Copernicus instead of adhering to the exploded theories of Ptolemaios, that fact would not by itself affect our estimate of the value of the " Novum Organon." And Comte's philosophic position, as I have here sought to define it, is no more shaken by his numerous scientific blunders than Bacon's position is shaken by the CH. viii.] ORGANIZATION OF THE SCIENCES. 233 fact that he repudiated the Copernican astronomy and refused to profit by tlie physical discoveries of Gilbert. But the allusion to the Logic of Science may here serve to remind us that, before we can thoroughly understand Comte's general conception of philosophy, there is another poiut of view from which his system of the sciences must be criticized; a point of view too little dwelt upon by Mr. Spencer, since by the due consideration of it we shall arrive at the deepest of the differences between the Comtean organization of the sciences and the Spencer ian organization which is here adopted. In order fairly to bring out this point, let us devote a chapter to considering the masterly enumeration of scientific methods, and the survey of the resources which the mind has at its disposal for the in- vestigation of phenomena, which Comte has made a part of his general philosophy of the sciences ; withholding, until "the sequel, the application which is to be made of the discussion. CHAPTEE IX. PHILOSOPHY AS AN OEGANON. The absence of Logic, as a distinct science, from the Comtean classification, has by most critics been rightly regarded as a serious defect. Nevertheless, before we can intelligently find fault with Comte, we must make sure that we understand his grounds for assigning to Logic no independent position. The explanation is more deeply implicated with his funda- mental conception of the Scope of Philosophy than has generally been suspected. But let us begin by considering the more obvious aspects of the case- The science of logic consists of two portions, — the doctrine of the syllogism, and the general theory of induction, the latter comprising a codification on the one hand of the methods of research, and on the other hand of the laws of evidence. But this twofold province of logic can hardly be said to have been clearly indicated untD. the publication of Mr. Mill's treatise. From the days of Aristotle down to the time when Comte wrote the " Philosophic Positive," the logic officially recognized and taught as such consisted almost exclusively of the doctrine of the syllogism. Besides this there was nothing save the Baconian logic, containing indeed many valuable hints for inquirers, but not organized into a coherent system. Now Comte held in small esteem the CH. IX.] PHILOSOPHY AS AN ORQANON. 235 syllogistic logic. He held, and justly, that something besides the scholastic quibbling over Baroco, Camestres and Barbara, was needed in prosecuting the search after new truths. To attempt, by prolonged dealing in these dialectic subtleties, to acquire the art of correct reasoning, was, in his opinion, much like trying to learn the art of correct speaking by pro- longed study of the rules of grammar. Men do not learn to swim, to fence, or to hunt, by reading elaborate treatises on gymnastics and sportsmanship. The study of rhetoric, how- ever thorough, careful and systematic, will never of itself enable us to write a clear and forcible style. We may know all the commandments of ethics by heart, and be able to utter the soundest judgment upon the comparative merits of the utilitarian and the intuitional theories, and yet be unable to lead upright lives. And similarly we may go on stringing together majors and minors until we are grey, and yet after all be unable to make an accurate observation, or perform a legitimate induction. Therefore, according to Comte, logic is not so much a science as an art, indispensable in the prose- cution of all the sciences, but to be learned only by practice. As philosophy, regarded as a general conception of the universe, has hitherto, like the mistletoe, had its roots in the air, but has now been brought down and seciirely planted in the fertile soil of scientific knowledge, so let us no longer permit logic to remain in isolation, feeding upon airy nothings, but let us bring it down and nourish it with scientific methods. As we learn to live rightly, not by dogmatic in- struction, but by the assiduous practice of right living, as we learn to speak properly and to write forcibly by practice and not by theory, so let us gain control of the various instru- ments for investigating Nature by the study of the several sciences in which those instruments come into play. . To become skilful in the use of deduction, let us study mathe- matics, especially in its direct applications to the solution of problems in astronomy and physics. If we would become 236 COSMIC PHILOSOPHY. [pt. i. accurate observers, and would enable ourselves properly to estimate the value of experimental reasoning, let us study those inductive sciences which exhibit practically the essential requisites of an accurate observation or a conclu- sive experiment. Even so, if we would attain literary ex- cellence, let us not fritter away OTir time in puerile attempts to imitate the favourite modes of expression of admired writers, but let us rather aim at directly expressing the thoughts that are in us, the result of our own observation and reflection, admitting no phrase which does not assist the exposition of the thought. If, as Buffon said, the style is the man, so also is the habit of thinking the man, save that in the one case as in the other, if it possess any merit, it is the man as modified and cultivated by a complex intercourse with phenomena. Such is Comte's opinion of logic, — an opinion common enough at the present day, but sufficiently novel to be revolutionary forty years ago. That the above views are in the main perfectly sound will now be questioned by no one, nor can it be doubted tliat they are of the highest importance. When put into practical operation, they are destined to work changes of fundamental importance in our methods of educa- tion. ISTevertheless, though sound enough as far as they go, these arguments are far from exhibiting the whole truth. Admitting unreservedly that, to become proficient in obser- vation and reasoning, we must learn logic, as we leain grammar and rhetoric, by practical experience ; it must still be maintained that there is need of a general doctrine of logic, as indeed there is also need of a general doctrine of grammar and rhetoric. Though a man may write an excel- lent style without having studied rhetoric systematically, yet it will be no injury, but rather an important help to him to understand theoretically the general principles on which a sentence should be constructed. In the fine arts, which afford an excellent test for judging this point, the superiority CH. IX.] PHILOSOPHY AS AN OBQANON. 237 imparted by systematic instruction is quite incontestable. Doubtless it is by long-continued practice that men learn to paint pictures, to mould statues, and to compose oratorios or symphonies. But it is none the less probable that Mozart and Beethoven would have accomplished comparatively little without the profound study of harmony; and in painting and sculpture the " originality of untaught geniuses " is, not unjustly, made a subject for sarcasm. It is therefore useless for Macaalay to remind us that men reasoned correctly long before Bacon had drawn up his elaborate canons of induc- tion ; or for Comte to appeal to rhetoric, grammar, and aesthetic art in support of the opinion that we need no general doctrine of logic. To take a concrete example, — if, as in Borda's experiment, you make a simple pendulum oscillate thirty hours in an exhausted receiver, by diminishing the friction at the point of support, and proceed to infer that with the total abolition of friction and atmospheric resistance the pendulum would oscillate for ever, it may not be essential to the validity of your inference that you should understand the character of the partictdar logical method which you are employing. Nevertheless it cannot but be of advantage to you to know that you are using the " method of concomitant variations," and to understand on general principles the conditions under which this method may be employed and the precautions required in order to make it valid. For want of such general knowledge of method, even trained physicists not unfre- quently make grave errors of inference, applying some powerful implement of research in cases where interfering circumstances, not sufficiently taken into account, render it powerless. Thus the method just alluded to, of varying the cause in order to observe and note the concomitant variations of the effect, is a very powerful instrument of induction ; but in order to use it effectively, we need to bear in mind two things. First, we need to know the quantitative relation 238 COSMIC PHILOSOPHY. [pt. i. between the variation of the cause and that of the effect; and secondly, we need to know that the intermixture of circumstances will not, after a certain point, alter the order of the variations. In the case of the pendulum, just cited, we know both of these points. We know that the only factors in the case are the momentum of the pendulum, acting in concert with gravity, the friction at the point of support, and the friction and resistance of the atmosphere ; and as we progressively diminish these latter retarding factors, we can calculate the exact ratio at which the retardation diminishes. We are therefore perfectly justified in concluding that if the friction and resistance could be utterly abolished, the momentum of the pendulum, acting in concert with gravity, woidd carry it backward and foi'ward for ever. But because the abstraction of heat causes the molecules of a body to approach each other, it is not safe to infer that, if all the heat were abstracted, the molecules would be in complete contact. This is a more or less plausible guess, not a true induction. "For since we neither know how much heat there is in any body, nor what is the real distance between any two of its particles, we cannot judge whether the con- traction of the distance does or does not follow the diminu- tion of the quantity of heat according to such a numerical relation that the two quantities would vanish simulta- neously." ^ In similar wise, from the fact that in alcoholic intoxication the severity of the narcotic symptoms varies according to the size of the dose, it is not legitimate to infer that a very small dose will cause slight narcotic symptoms or even a tendency to the production of such symptoms. For we can neither ascertain the quantitative ratio between the variation in the dose and the variation in the narcosis, nor in the case of such a complex aggregate as the human organism can we assert the absence of interfering conditions which, after a certain point, will entirely change the order of ^ Mill, System of Logic, 6tli edition, vol. i. p. 447. H. IX.] PHILOSOPHY AS AN ORGANON. 239 the two variations. In point of fact there are such interfer- ing conditions, due partly to the control exercised by the sympathetic nerve over the contraction and dilatation of the cerebral blood-vessels, and partly to other circumstances too complicated to be here mentioned. Now it is the business of logic to codify, upon abstract principles, the rules of scientific investigation ; to determine what shall be admitted as trustworthy evidence, and what shall not be so admitted ; to point out the class of problems which each implement of research is best fitted to solve ; and to enumerate the precautions which must be taken in ordei" to use each implement with skill and success. Logic is therefore a science which contributes to all the others, and to which all the others contribute. Though we may, and indeed must, acquire familiarity with its methods by direct practice in the study of the various sciences, yet the advantage of understanding the general theory of those methods, as a science by itself, cannot well be questioned after the foregoing explanation. To become familiar with the values of different kinds of evidence, and with the processes by which evidence is procured, a lawyer must practise in court; yet every lawyer thinks it necessary to master the general theory of evidence as presented in special treatises. Logic is to the philosopher and the scientific inquirer what the law of evidence is to the lawyer ; and the need for its theoretical study rests upon the admitted principle that, in all branches of human activity, rational knowledge is better than empirical knowledge. In order to be always sure that we are generalizing correctly, we must make the generalizing process itself a subject of generalization. But although Comte did not dignify logic with the rank of an independent science, he more than atoned for the omission by his contributions to the study of logic. Since the era of Bacon and Descartes, no book had appeared containing such profound views of scientific method as the "Philosophic 240 COSMIC PHILOSOPHY. [pt. i. Positive." It has since been surpassed and superseded in many respects by Mr. Mill's "System of Logic ;" but Mr. Mill would be the first to admit that, but for the work of Comte, his own work would have been by no means what it is. ^ Comte's most important innovation consisted in com- prehensively assigning to each class of phenomena its appropriate method of investigation, and in clearly marking out the limits within which each method is applicable. It is this which gives to the first three volumes of the " Philosophie Positive " the- character of a general treatise on scientific method, and which makes them still interesting and profitable reading, even in those chapters on physics, chemistry and biology, which in nearly all other respects the recent revolu- tions in science have rendered thoroughly antiquated. Comte intended this portion of his work especially for a new Organou of scientific research, which should influence educational methods in the future, as well as assist in determining the general conception of the universe. He calls attention to the futility of approaching the most com- plicated phenomena, such as those of life, individual or social, without having previously, by the study of the simpler sciences, learned what a law of nature is, what a scientific conception is, what is involved in making an accurate observa- tion, what is requisite to a sound generalization, what are the various means of verifying conclusions obtained by deduction. Continually we witness the spectacle of scientific specialists, jxistly eminent in their own department of research, who do not scru]Dle to utter the most childish nonsense upon topics with which they are but slightly acquainted. The reason is that they have learned to think correctly after some particular fashion, but know too little of the general principles on which thinking should be conducted. In such a con- dition — owing to the discredit which the manifest failure of metaphysics has for the time being cast upon philosophy in ^ This is perliaps too strongly stated. See Mill's AiitoMography, pp. 207-213, 245. CD. IX.] PHILOSOPHY AS AN OllGANON. 241 general — are too many of our scientific savants of the present century ; whose narrowness of mind, in dealing with philosophic questions, Comte was never weary of pointing out and tracing to its true source in the defective mastery of logical methods. The cure for this narrowness is to be found in a philosophic education which shall ensure familiarity with all logical methods by studying each in connection with that order of phenomena with which it is most especially fitted to deal. According to Comte, the resources which the mind has at its disposal for the inductive investigation of phenomena are three in number, — namely. Observation, Experiment, and Comparison. Strictly speaking, experiment and comparison are only more elaborate modes of observation ; but they are nevertheless sufficiently distinct from simple observation to make it desirable, for practical purposes, to rank them as separate processes. Concisely stated, the difference is as follows. In simple observation, we merely collate the phenomena, as they are presented to us. In experiment, we follow the Baconian rule of artificially varying the circum- stances. In comparison, we watch the circumstances as they are varied for us on a great scale by Nature. Answering to the two processes of observation and ex- periment, as Mr. Mill has shown, there are two inductive methods, — the Method of Agreement and the Method of Difference. The former compares different instances of a phenomenon, to ascertain in what respects they agree, while the latter compares an instance of the occurrence of a phenomenon with an instance of its non-occurrence, to ascertain in what respects they differ. To cite from Mr. Mill's " System of Logic " a pair of examples : — " When a man is shot through the heart, it is by the method of differ- ence we know that it was the gun-shot which killed him ; for he was in the fulness of life immediately before, all circum- stances being the same except the wound." On the other VOL. I. K 242 COSMIC PHILOSOPHY. [pt. i. hand, in inquiring into the cause of crystallization, M^e employ the method of agreement as follows. " We compare instances in which bodies are known to assume crystalline structure, but which have no other point of agreement ; and we find them to have one, and as far as we can observe, only one, antecedent in common, — the deposition of a solid matter from a liquid state, either a state of fusion or of solution. We conclude, therefore, that the solidification of a substance from a liquid state is an invariable antecedent of its crystallization." In this particular case we may say that it is not only the invariable antecedent, but the unconditional invariable antecedent, or cause ; since, having detected the antecedent, we may produce it artificially, and find that the effect foHo-ws it. It was thus in Sir James Hall's splendid experiment, in which " he produced artificial marble by the cooling of its materials from fusion under immense pressure." And it was thus when Dr. WoUaston, " by keeping a vial of water charged with siliceous particles undisturbed for years, succeeded in obtaining crystals of quartz." Manifestly, however, unless we can artificially produce the antecedent, and so reason back from cause to effect, our method of agreement is not exhaustively conclusive. Unless we can be sure that the observed antecedent is the only one common to all the instances, the sequence may turn out to be only a derivative sequence, like that of day and night. And unless the phenomena are very simple, we cannot be sure that the observed common antecedent is the only one. It is otherwise with the method of difference. Whenever we can bring that method to bear upon the phenomena, its results are finally conclusive ; since it is the very essence of that method to compare two instances which are exactly alike in every respect save in the presence or absence of the given antecedent. Unfortunately, in the operations of nature these requisites are seldom fulfilled. So that the method of difference " is more particularly a method of artificial experi- CH. IX.] PHILOSOPHY AS AN OROANON. 243 ment ; while that of agreement is more especially the resource employed where experimentation is impossible." Now in astronomy we can employ only simple observation. The magnitude and the inaccessibility of the phenomena render it impossible for us to vary the circumstances, so that experiment is out of the question. Nevertheless, here the phenomena are so simple that the method of agreement alone carries us far toward certainty ; and accordingly in astronomy the art of observation has been brought to such a pitch of perfection, and the conditions of an accurate observation are so thoroughly understood, that it is here that the use of this implement of induction must be studied. In physics, both molar and molecular, and in chemistry, the phenomena become far more complicated. Yet here we become able to vary the phenomena almost indefinitely ; and accordingly physics and chemistry are the inductive sciences par excellence, in which experiment, the great engine of in- duction is employed most successfully, and in which, there- fore, is especially to be studied the proper use of the method of difference. When we come to biology, we are met by a still greater complication of phenomena ; but according to the luminous principle, first suggested by Comte, that in general our means of iavestigation increase with the complexity of the pheno- mena, we have here an additional weapon of investigation. We stUl retain the ability to experiment ; although such is the intricacy of the circumstances, and such the subtlety of the causes in operation, that we can seldom apply the potent method of difference. We can seldom be sure that the two instances compared agree in everythiag save in the presence or absence of the circumstance we are studying.^ In expe- rimenting upon live animals, we are liable to cause a patho- ' A striking illustration of this truth is furnished by the controversy now going on concerning archebiosis or "spontaneous generation." See below, part ii. chap. viii. E 2 244 COSMIC PHILOSOPHY. [pt. i. logical state, and set in motion a whole series of phenomena which ohscure those which we wish to observe. It is instruc- tive, and often amusing, to read some treatise on experimental physiology, like those of Magendie and Claude Bernard, and see how easy it is for equally careful investigators to arrive at totally irreconcilable results. It is not to be denied that experiment is of vast importance in biology, and has already achieved wonders. Nevertheless, the practical study of experimentation should never be begun in biology, but in chemistry or physics, where the conditions are simpler. Having learned from these sciences the general theory of sound experimenting, we may afterward safely proceed to apply the same method to vital phenomena. The additional implement possessed by the organic sciences is comparison, to which corresponds the Method of Concomi- tant Variations, already described. It is true we can also employ this method to a large extent in the simpler sciences, but it is in biology that it attains its maximum efficiency. Here we have a series of instances already prepared for us by Nature, in which certain antecedents and consequents vary together. We have a vast hierarchy of organisms, each exhibiting some organ and the corresponding function more or less developed than it is in the others. To trace the functions of the nervous system, or to follow the process of digestion, in its increasing complication, from the star-fish up to man, is to employ the logical method of comparison. And if any one wishes to realize the immense power of this method, let him reflect upon the revolution which was wrought in the science of biology when Lamarck and Cuvier began the work of comparison upon a large scale. Hence, it is that biology is eminently the science of classi- fication ; and if skill in the use of this powerful auxiliary of thought is to be acquired, it must be sought in the compara- tive study of the vegetable and animal kingdoms. Theoretical logic may divide and subdivide as much as it likes ; but OIL IX.] PHILOSOPHY JS AN ORG ANON. 245 genera and species are dull and lifeless things, when contem- plated merely in their places upon a logical chart. To become correct reasoners, it is not enough that we should know what classes and sub-classes are ; we should also be able skilfully to make them. I conclude with a citation from Mr. Mill : — "Although the scientific arrangements of organic nature afford as yet the only complete example of the true principles of rational classification, whether as to the formation of groups or of series, those principles are applicable to all cases in which mankind are called upon to bring the various parts of any extensive subject into mental coordination. They are as much to the point when objects are to be classed for purposes of art or business, as for those of science. The proper arrangement, for example, of a code of laws depends on the same scientific conditions as the classifications in natural history ; nor could there be a better preparatory discipline for that important function, than the study of the principles of a natural arrangement, not only in the abstract, but in their actual application to the class of phenomena for which they were first elaborated, and which are stiU the best school for learning their use. Of this, the great authority on codification, Bentham, was perfectly aware ; and his early ' Fragment on Government,' the admirable introduction to a series of writmgs unequalled in their department, contains clear and just views (as far as they go) on the meaning of a natural arrangement, such as could scarcely have occurred to anyone who lived anterior to the age of Linnseus and Bernard de Jussieu." ^ These illustrations will serve to give the reader some idea of Comte's brilliant and happy contributions to the logic of scientific inquiry. I am aware that scanty justice is done to the subject by the condensed and abridged mode of treat- ment to which I have felt obliged to resort. But an exhaus- tive exposition and criticism of the details of the Comtean •' System of Logic, 6th edit., vol. ii. p. 288. 246 COSMIC FHILOSOPHY. [pt. i. philosophy of method does not come within the scope of the present work. The object of the preceding sketch is to enable the reader to realize the significance of Comte's omis- sion of Logic from the scheme of the sciences. That omis- sion, as we may now see, was clue to the fact that Comte merged Philosophy in Logic. Or, in other words, from his point of vieiv, Philosophy is not a Synthesis, hut an Organon. Nowhere in that portion of the " Philosophic Positive " which treats of the organization of the sciences, do we catch any glimpse of that Cosmic conception of the scope of philosophy which was set forth and illustrated in the second chapter of these Prolegomena. For according to that conception, we have seen that philosophy is an all-comprehensive Synthesis of the doctrines and methods of science ; a coherent body of theorems concerning the Cosmos, and concerning Man in his relations to the Cosmos of which he is part. Now, though Comte enriched mankind with a new conception of the aim, the methods, and the spirit of philosophy, he never even attempted to construct any such coherent body of theorems. He constructed a classification of the sciences and a general theory of scientific methods ; but he did not extract from each science that quota of general doctrines wliich it might be made to contribute toward a imiversal doctrine, and then proceed to fuse these general doctrines into such a universal doctrine. From first to last, so far as the integration of science is concerned, his work was logical rather than philosophical. And here we shall do well to note an apparent confusion between these two points of view, which occurs in Mr. Mill's essay on Comte. " The philosophy of science," says Mr. Mill, " consists of two principal parts ; the methods of investigation, and the requisites of proof. The one points out the roads by which the human intellect arrives at conclusions ; the other, the mode of testing their evidence. The former, if complete, would be an Organon of Discovery; the latter, of Proof." Now I call this an on. IX.] PHILOSOPHY A8 AN OPMANON. 247 admirable definition ; but it is not the definition of Philo- sophy, it is the definition of Logic. If we were to accept it as a definition of philosophy, we might admit that Comte con- structed a philosophy ; as it is, we can only admit that he constructed a logic, or general theory of methods. In the present chapter we have seen how valuable were his contri- butions to the logic of induction. We may admit, with Mr. Mill, that he treats this subject " with a degree of perfection hitherto unrivalled," — save (I should say) by Mr. Mill him- self. But an Organon of Methods is one thing, and a Syn- thesis of Doctrines is another thing ; and a system of philosophy which is to be regarded as a comprehensive theory of the universe must include both. Yet Comte never attempted any other synthesis than that wretched travesty which, with reference to the method employed in it, is aptly entitled " Synthese Subjective." Not only does Comte thus practically ignore the conception of philosophy as a Synthesis of the most general truths of science into a body of universal truths relating to the Cosmos as a whole, but there is reason to believe that had such a conception been distinctly brought before his mind, he would have explicitly condemned it as chimerical. In illustration of this I shall, at the risk of apparent digression, cite one of his conspicuous shortcomings which is peculiarly interesting, not only as throwing light upon his intellectual habits, but also as exemplifying the radical erroneousness of his views concerning the limits of philosophic inquiry. Prof. Huxley calls attention to Comte's scornful repudiation of what is known as the " cell-doctrine " in anatomy and phy- siology. Comte characterized this doctrine as a melancholy instance of the abuse of microscopic investigation, a chimeri- cal attempt to refer all tissues to a single primordial tissue, " formed by the unintelligible assemblage of a sort of organic monads, which are supposed to be the ultimate units of every living body." Now this " chimerical doctrine " is at the 248 COSMIC PHILOSOPHY. [pt. t. present day one of the fundamental doctrines of biology. Other instances are at hand, which Prof. Huxley has not cited. For example, Comte condemned as vain and useless all inquiries into the origin of the human race, although, with an inconsistency not unusual with him, he was a warm advocate of that nebular hypothesis which seeks to account for the origin of the solar system. As these two orders of inquiry are philosophically precisely on a level with each other, the former being indeed the one for which we have now the more abundant material, the attempted distinction is proof of the vagueness with which Comte conceived the limits of philosophic inquiry.-' But what shall we say when we find Mm asserting the impossibility of a science of stellar astro- nomy ? He tells us that we have not even the first datum for such a science, and in all probability shall never obtain that datum. Until we have ascertained the distance, and cal- ^ It is interesting to note that disciples of Comte are still to be found, so incapatle of realizing that the arbitrary dicta of tlieir master did not consti- tute the final utterance of human science, that they oppose the Doctrine of Evolution upon no other ground than the assumed incapacity of the human mind for dealing with origins ! In a discussion held in New York some two years since on the subject of "Darwinism," a certain disciple of Comte observed that it was useless for man to pretend to know how he originated, when he could not ascertain the origin of anything ! Nevertheless, since we do find ourselves able to point out the origin of many things, from a myth or a social observance to a freshet or the fall of an avalanche, it appears that our Comtist was playing upon words after tlie scholastic or Platonic fashion, and confounding proximate "origin," which is a subject for science,' with ultimate "origin," which must be relegated to metaphysics. Had Comte carried out this principle consistently, he would never have written his Philosophy of History, since the explanation of the social phenomena existing in any age is the determination of their mode of origin from the social phenomena of the preceding age. But if with the aid of historic data we may go back three thousand years, there is no reason why, with the aid of geologic, astronomic, and chemical data, we should not go back, if necessary, a thousand billion years, and investigate the origin of the earth from the solar nebula, or the origin of life from aggregations of colloidal matter. In either case, the problem is one, not of ultimate origin, but" of evolution. In neither ease do we seek to account for the origin of the matter and motion which constitute the phenomenal universe, but only to discover a formula which shall express the common characteristics of certain observed or inferred redistributions of the matter and motion already existing. The latter attempt is as clearly within the limits of a scientific philosophy as the former is clearly beyond them. cii. IX.] PHILOSOPHY AS AN OBGANON. 249 culated the proper motion, of at least one or two fixed stars, we cannot be certain even that the law of gravitation holds in these distant regions. And the distance of a star we shall probably never be able even approximately to estimate. Thus wrote Comte in 1835. But events, with almost malicious rapidity, falsified his words. In less than four years, Bessel had measured the parallax of the star 61 Cygni, — the first of a brilliant series of discoveries which by this time have made the starry heavens comparatively familiar ground to us. What would Comte's scorn have been, had it been suggested to him that within a third of a century we should possess many of the data for a science of stellar chemistry ; that we should be able to say, for instance, that Aldebaran contains sodium, magnesium, calcium, iron, bismuth, and antimony, or that all the stars hitherto observed with the spectroscope contain hydrogen, save /8 Pegasi and a Orionis, which apparently do not ! Or what would he have said, had it been told him that, by the aid of the same instrument which now enables us to make with perfect confidence these audacious assertions, we should be able to determine the proper motions of stars which present no parallax ! No * example could more forcibly illustrate the rashness of pro- phetically setting limits to the possible future advance of science. Here are truths which, within the memory of young men, seemed wholly out of the reach of observation, but which are already familiar, and will soon become an old story. I believe it was Comte's neglect of psychological analysis which caused him to be thus over-conservative in accepting new discoveries, and over-confident in setting limits to scientific achievement. He did not clearly distinguish be- tween the rashness of metaphysics and the well-founded boldness of science. He was deeply impressed with the futility of wasting time and mental energy in constructing unverifiable hypotheses; but he did not sufficiently distin- 250 COSMIC PHILOSOPHY. [i-T. i. guish between hypotheses which are temporarily unverifiable frora present lack of the means of observation, and those which are permanently unverifiable from the very nature of the knowing process. There is no ground for supposing that Comte ever thoroughly understood why we cannot know the Absolute and the Infinite. He knew, as a matter of historical fact, that all attempts to obtain such knowledge had miser- ably failed, or ended in nothing better than vain verbal wrang- lings ; but his ignorance of psychology was so great that he probably never knew, or cared to know, why it must neces- sarily be so. Had he ever once arrived at the knowledge that the process of knowing involves the cognition of like- ness, difference, and relation, and that the Absolute, as presenting none of these elements, is trebly unknowable, he would never have confounded purely metaphysical hypo- theses with those which are only premature but are never- theless scientific. He would have seen, for instance, that our inability to say positively whether there are or are not living beings on Saturn results merely from our lack of sufficient data for a complete induction ; whereas our inability to frame a tenable hypothesis concerning matter per se results from the eternal fact that we can know nothing save under the conditions prescribed by our mental structure. Could we contrive a telescope powerful enough to detect life, or the products of art, upon a distant planet, there is nothing in the constitution of our minds to prevent our appropriating such knowledge ; but no patience of observation or cunning of experiment can ever enable us to know the merest pebble as it exists out of relation to our consciousness. Simple and obvious as this distinction appears, there is much reason to believe that Comte never understood it. He inveighs against inquiries into the proximate origin of organic life in exactly the same terms in which he condemns inquiries into the ultimate origin of the universe. He could not have done this had he perceived that the latter question is for ever cii. IX.] PHILOSOPHY AS AN OKGANON. 251 insoluble because it involves absolute beginning ; whereas the former is merely a question of a particular combination of molecules, which we cannot solve at present only because we have not yet obtained the requisite knowledge of the interactions of molecular forces, and of the past physical condition of the earth's surface. In short, he would have seen that, while the human mind is utterly impotent in the presence of noumena, it is well-nigh omnipotent in the presence of phenomena. In science we may be said to advance by geometrical progression. Here, in the forty years which have elapsed since Comte wrote on physical science, it is hardly extravagant to say that the progress has been as great as during the seventeen hundred years between Hipparchos and Galileo. If then, in the three or four thousand years which have elapsed since Europe began to emerge from utter barbarism, we have reached a point at which we can begin to describe the chemical constitution of a heavenly body seventy thousand million miles distant, what may not science be destined to achieve in the next four thousand, or forty thousand, years? We may rest assured that the tale, if we could only read it, would far excel in strangeness anything in the " Arabian Nights " or in the mystic pages of the Bollandists. But Comte did not understand all this. He, the great overthrower and superseder of metaphysics, did not really apprehend the distinction between metaphysics and science. Hence every hypothesis which went a little way beyond the limited science of his day he wrongly stigmatized as " meta- physical." Hence he heaped contumely upon the cell-doc- triae, only three years before Schwann and Schleiden finally established it. And hence, when he had occasion to observe that certain facts were not yet known, he generally added, "and probably they never wiU be," — though his prophecy was not seldom confuted, while yet warm from the press. Toward the close of his life, after he had become sacer- 253 COSMIC FHILOSOFRY. [pt. i. dotally inclined, this tendency assumed a moral aspect. These remote and audacious inquiries into the movements of stars, and the development of cellular tissue, and the origin of species should not only be pronounced fruitless, but should be frowned upon and discountenanced by public opinion, as a pernicious waste of time and energy, which might better be devoted to nearer and more practical objects. It is a curious illustration of the effects of discipleship upon the mind, that several of Comte's disciples — Dr. Bridges among others less distinguished — maintain this same opinion, for no earthly reason, I imagine, save that Comte held it. It is certainly a strange opinion for a philosopher to hold. It bears an unlovely resemblance to the prejudice of the Philistines, that all speculation is foolish and empty which does not speedily end in bread-and-butter knowledge. Who can decide what is useful and what is useless ? We are told first that we shall never know the distance to a star, and secondly that even if we could know it, the knowledge would be useless, since human interests are at the uttermost bounded by the solar system. Three years suffice to dis- prove the first part of the prediction. In a little while the second part may also be disproved. We are told by Comte that it makes no diiference to us whether organic species are fixed or variable ; and yet, as the Darwinian controversy has shown, the decision of this question must affect from begin- ning to end our general conception of physiology, of psycho- logy, and of history, as well as our estimate of theology. If it were not universally felt to be of practical consequence, it would be argued calmly, and not with the weapons of ridicule and the odmm theologicum. But this position — the least de- fensible one which Comte ever occupied — may best be refuted by his own words, written in a healthier frame of mind. " The most important practical results continually flow from theories formed purely with scientific intent, and which liavc sometimes been pursued for ages without any practical en. IX.] PHILOSOPHY AS AN OEGANON. 253 result. A remarkable example is furnished by the beautiful researches of the Greek geometers upon conic sections, which, after a long series of generations, have renovated the science of astronomy, and thus brought the art of navi- gation to a pitch of perfection which it could never have reached but for the purely theoretic inquiries of Archimedes and Apollonios. As Condorcet well observes, the sailor, whom an exact calculation of longitude preserves from ship- wreck, owes his life to a theory conceived, two thousand years ago, by men of genius who were thinking of nothing but lines and angles.'' This is the true view ; and we need not fear that the scientific world will ever adopt any other. That inborn curiosity which, according to the Hebrew legend, has already made us like gods, knowing good and evil, will continue to inspire us until the last secret of Nature is laid bare ; and doubtless, in the untiring search, we shall uncover many priceless jewels, in places where we least expected to find them. The foregoing examples will suffice to illustrate the vague- ness with which Comte conceived the limits of scientific and of philosophic inquiry. T have here cited them, not so much for the sake of exhibiting Comte's mental idiosyncrasies, as for the sake of emphasizing the radical difference between his conception of the scope of philosophy and the conception upon which the Cosmic Philosophy is founded. In giving to Comte the credit which he deserves, for having heralded a new era of speculation in which philosophy should be built up entirely out of scientific materials, we must not forget that his conception of the kind of philosophy thus to be built up was utterly and hopelessly erroneous. Though he insisted upon the all-important truth that philosophy is simply a higher organization of scientific doctrines and methods, he fell into the error of regarding philosophy merely as a logical Organon of the sciences, and he never framed the conception of philosophy as a Universal Science 254 COSMIC PHILOSOPHY. [pt. i. in which the widest truths obtainable by the several sciences are contemplated together as corollaries of a single ultimate truth. Not only did he never frame such a conception, but there can be no doubt that, had it ever been presented to him in all its completeness, he would have heaped oppro- brium upon it as a metaphysical conception utterly foreign to the spirit of Positive Philosophy. We have just seen him resolutely setting his face against those very scientific specu- lations to which this conception of the scope of philosophy owes its origin ; and we need find no dif&culty in believing Dr. Bridges when he says that the Doctrine of Evolution would have appeared to his master quite as chimerical as the theories by which Thales and other Greek cosmogonists " sought to deduce all things from the principle of Water or of Fire.'' Thus in a way that one would hardly have anticipated, we have disclosed a fundamental and pervading difference be- tween the Positive and the Cosmic conceptions of philosophy. The apparently subordinate inquiry into Comte's reasons for excluding Logic from his scheme of sciences, has elicited an answer which gravely affects our estimate of his whole system of thought. That his conception of Philosophy as an Organon was a noble conception, there is no doubt ; but that it was radically different from our conception of Philo- sophy as a Synthesis, is equally undeniable. But the full depth and significance of this distinction will only be appre- ciated when, in the following chapter, we shall have pointed out the end or purpose for which this scientific Organon was devised. CHAPTER X. COSMISM AND POSITIVISM. Toward the close of the chapter on "Phenomenon and Noumenon," I observed that it has become customary to identify with Positivism every philosophy which rejects all ontological speculation, which seeks its basis in the doctrines and methods of science, and which is accordingly arranged in opposition to the current mythologies. The confusion is one which, after having once been originated, it is easy to maintain but exceedingly difficult to do away with ; since on the one hand, it is manifestly convenient for the theologian to fasten upon every new and obnoxious set of doctrines the odium already attaching to quasi-atheistic Positivism ; while on the other hand, the disciples of Comte are not unnaturally eager to claim for themselves every kind of modern thinking that can by any colourable pretext be annexed to their own province. The theological magazine- writer, who perhaps does not know what is meant by the Eelativity of Knowledge but feels that there is something to be dreaded in Mr. Hansel's negations, finds an excellent substitute for intelligent criticism in the insinuation that this doctrine of relativity is a device of the Positivists, who refuse to admit the existence of God, and worship Humanity " symbolized as a woman of thirty, with a child 256 COSMIC PHILOSOPn Y. [pt. i in her arms." In similar wise the ardent disciple of Comte — who, so far as my experience goes, is not unlikely to be quite as narrow-minded as any theologian— is wont to claim all contemporary scientific thinkers as the intellectual off- spring of his master, until their openly expressed dissent has reduced him to the alternative of stigmatizing them as "metaphysical;" very much as the Pope lays claim to the possession of all duly baptized Christians,^ save those whom it has become necessary to excommunicate and give over to the Devil. But aside from these circumstances, which partly explain the popular tendency to classify all scientific thinkers as Positivists, it is not to be denied that there are really plausible reasons why the Positive Philosophy should currently be regarded as representative of that whole genus of contemporary thinking which repudiates the subjective method, and, as Mr. Spencer says, " prefers proved facts to superstitions." As I have already shown, it was Comte who first inaugurated a scheme of philosophy explicitly based upon the utter rejection of anthropomorphism and the adop- tion of none but scientific doctrines and methods. I have already pointed out how great are our obligations to him for this important work, and I need not repeat the acknowledg- ment. For this reason it is obvious that whenever the theological thinker encounters a system which as far as possible rejects anthropomorphic interpretations, and when- ever the metaphysician encounters a system which denies the validity of his subjective method, both the one and the other will quite naturally regard this system as some phase of Positivism. For the same reason, when we remember how strong is the tendency to "read between the lines" of any system of thought and thus to interpret it in accordance with our pre-conceptions, we shall see how easy it is for those who ' See the amusing letter of Pius IX. to the Emperor of Germany, dated August 7th, 1873. CH. X.] COSMISM AND POSITIVISM. 257 first derived from Comte their notions of scientific method and of the limits of plailosophic inquiry, to " read into " his system all the later results of their intellectual experience, and thus to persist in regarding the whole as Positive Philosophy. Of this tendency it seems to me that we have an illustrious example in Mr. Lewes, the learned historian of philosophy and acute critic of Kant, who in the latest edition of his " History " still maintains that the agreement between Comte and Spencer is an agreement in fundamentals, while the differences between them are non-essential differences. That I am not incapable of understanding and sympathizing with this tendency, may be inferred from the fact that during eleven years I espoused the same plausible error, and called myself a Positivist (though never a follower of Comte) in the same breath in which I defended doctrines that are utterly incompatible with Positivism in any legitimate sense of the word. So long as we allow our associations with the words to colour and distort our scrutiny of the things — a besetting sin of human philosophizing, from which none of us can hope to have entirely freed himself — so long it is possible for ns to construct an apparently powerful argument in behalf of the fundamental agreement between Spencer and Comte. It may be said, for example, that both philosophers agree in asserting : I. That all knowledge is relative ; TI. That all unverifiable hypotheses are inadmissible ; III. That the evolution of philosophy, whatever else it may be, has been a process of deanthropomorphization ; IV. That philosophy is a coherent organization of scientific doctrines and methods ; V. That the critical attitude of philosophy is not destruc- tive but constructive, not iconoclastic but conservative, not negative but positive. Still confining our attention to the form of these proposi- tions, and neglecting for the moment the very different VOL. I. s 258 COSMIC FHILOSOFHY. [pt. i. meanings with whicli they would be enunciated respectively by the Cosmist and by the Positivist, it is open to us to maintain that, in asserting these propositions, Mr. Spencer agrees with Comte in asserting the five cardinal theorems of Positive Philosophy. Looking at the matter in this light, we might complain that Mr. Spencer, in his "Eeasons for Dissenting, etc.," accentuates the less fundamental points in which he differs from Comte, and passes without emphasis the more fundamental points in which he agrees with Comte. We might urge that while the " Law of the Three Stages " is undoubtedly incorrect, nevertheless the essential point is that men's conceptions of Cause have been becoming ever less and less anthropomorphic. And similarly, when Mr. Spencer insists that Comte has not classified the sciences correctly, we might reply that, if we were to question M. Littr^ (who still holds to the chief positions of the Comtean classifica- tion), he would perforce admit that the fundamental point— the ground-question, as Germans say — is not whether physics comes after astronomy, or whether biology is an abstract science, but whether or not the sciences can be made to furnish all the materials for a complete and unified conception of the world. In this statement of the case, which once seemed to me satisfactory, we have probably the strongest argument that can be devised in favour of the identification of Mr. Spencer's philosophy with Positivism, Yet, as above hinted, and as will be self-evident to everyone who has comprehended the foregoing chapters, its apparent strength rests entirely upon the verbal ambiguity of the five cardinal propositions, which are stated in such a way as to conceal the real points at issue between the two philosophies. "With regard to the first two propositions, I have already shown that they are in nowise so peculiar to Comte that allegiance to them should make us his disciples or coadjutors. In accepting the Doctrine of Eelativity, as well as in receiving from modern science the CH. X.] GOSMTSM AND POSITIVISM. 259 inheritance of the Objective Method, we are the " heirs of all the ages," and are in nowise especially beholden to Cointe. As regards the fifth proposition, concerning the critical attitude of philosophy, the discussion of it does not belong to our Prolegomena but to our Corollaries, since before we can comprehend it we must make sure that we understand what is implied by the Doctrine of Evolution. In the con- cluding chapter of this work it will appear that our dissent from Positivism is practically no less emphatic in resx^ect to the critical attitude of philosophy than in other respects. For the present we can willingly dispense with this proof, as our point will be quite sufficiently established by an examina- tion of the third and fourth propositions above alleged as cardinal alike to Positivism and to Cosmism. And first, as regards the fourth proposition, the preceding chapter showed that Comte's conception of the scope and functions of philosophy was by no means the same as that which lies at the bottom of the present work. We have seen that he treated philosophy as merely an Organon of scientific methods, and totally ignored the conception of philosophy as a Synthesis of truths concerning the Cosmos. Now in order to comprehend the full purport of this, we must ask what was Comte's aim in constructing a system of philosophy ? To what end, was this elaborate Organon devised f It was not devised for the purpose of aiding the systematic exploration of nature in all directions, for we have seen that Comte began by discouraging and ended by anathematizing a large class of most important inquiries, chiefly on the ground of their "vainness" or "inutility." To understand the purpose of all this admirable treatment of philosophy as an Organon, we must take into account the statement of Dr. Bridges that Comte's philosophic aims were not different in his later epoch from what they had been in the earlier part of his career. From the very outset Comte intended to crown his work of reorganizing philosophy by constructing s 2 2(iO COSMIC PHILOSOPHY. [ft. i. a polity which should be competent to reorganize society. The belief that society can be regenerated by philosophy is a belief which underlies all his speculations from first to last. His aims were as practical as those of Saint-Simon and Fourier, the difference being chiefly that these un- scientific dreamers built their Utopias upon abstract theories of human nature, while Comte sought to found his polity upon the scientific study of the actual tendencies of humanity as determined by its past history. In a future chapter I shall have occasion to show that this whole attempt of Comte's was based upon a profound misconception of the ■true state of the case. For the present we need only observe that with Comte the construction of a Philosophy meant ultimately the construction of a Sociology, to which all his elaborate systematization of scientific methods was intended to be ancillary. Why must we study observation in astro- nomy, experiment in physics and chemistry, comparison in biology? In order, says Comte, to acquire the needful mental training for sound theorizing in sociology. To him the various physical sciences were not sources from which grand generalizations were to be derived, embracing the remotest and most subtle phenomena of the Universe ; they were whetstones upon which to grind the logical implements to be used in constructing a theory of Humanity. All other theorizing was to be condemned, save in so far as it could be shown to be in some way subservient to this purpose. Thus Comte's conception of philosophy was throughout an- thropocentric, and he utterly ignored the cosmic point of view. There can be little doubt that he who, in 1830, rejected the development-theory, which a more prescient thinker, like Goethe, was enthusiastically proclaiming, would have scorned as chimerical and useless Mr. Spencer's theory of evolution. We may now begin to see why Comte wished to separate Man from the rest of the organic creation, and why he was so eager to condemn sidereal astronomy, the CH. X.] COSMISM AND POSITIVISM. iHl study of which tends in one sense to dwarf our conceptions of Humanity. Comte was indeed too much of an astronomer to retreat upon the Ptolemaic theory, but in his later works he shows symptoms of a feeling like that which actuated Hegel, when he openly regretted the overthrow of the ancient astro- nomy, because it was more dignified for man to occupy the centre of the universe ! It is true that, in his first great work, Comte points out the absurdity of the theological view of man's supremacy in the universe, and rightly ascribes to the Copernican revolution a considerable share in the over- throwing of this view, and of the doctrine of final causes, with which it is linked. In spite of aU this, however, and in spite of his admirable scientific preparation, Comte's con- ception of philosophy as the summary of a hierarchy of sciences, presided over by sociology, led him irresistibly toward the anthropocentric point of view; and so, when it became necessary for him to crown his work by indicating its relations to religion, he arrived, logically enough, at a Eeligion of Humanity, although in order to reach such a terminus he was obliged to throw his original Positivism overboard and follow the subjective method. In view then of all this complicated difference between the Positivist con- ception of philosophy and the conception expounded in this work, I think we are quite justified in designating our own conception by a different and characteristic name. But the most fatal and irreconcilable divergence appears when we come to consider the third cardinal proposition, — that which relates to deanthropomorphization. If we inquire how it was that Comte was enabled to perpetrate, in the name of philosophy, such a prodigious piece of absurdity as the deification of Humanity, we shall find the explanation to lie in his misconception of what is meant by the relativity of knowledge. A good illustration of his confused thinking on this subject, to which I have already had occasion to refer, is afforded by his treatment of atheism. Comte had 262 COSMIC PHILOSOPHY. [pt. i. no patience with atheists, because of the chiefly negative and destructive character of the atheistic philosophy domi- nant in the eighteenth century. But when he lets ns into his philosophic reasons for rejecting atheism, we find him complaining of the atheists, not because of their denial of Deity, nor because their doctrine contravenes the relativity of knowledge, but because they indulge in " metaphysical at- tempts to explain the origin of life upon the earth's sur- face." (!) On reading such passages, it becomes sufficiently evident that Comte did not really understand why meta- physical inquiries are illegitimate, but rejected them very much as the general reader might reject them, because they muddled his mind ; and we may acknowledge the justice of Prof. Huxley's sarcasm, that " metaphysics " is, with Comte a " general term of abuse for anything that he does not like." Certain it is that Comte never understood the true import of the doctrine of relativity, as it is stated in our fourth chapter, — that there exists an Unknowable Eeality, of which all phe- nomena, as presented in consciousness, are the knowable manifestations. As I have already observed, his most illus- trious follower, M. Littr4 unreservedly stigmatizes as " meta- physical " this very doctrine of the Unknowable, upon which the Cosmic Philosophy bases its rejection of metaphysics. Had Comte ever understood this doctrine, he would neither have sought to impose upon us a phenomenal God, in the form of idealized Humanity, nor would he have virtually abandoned his original Positivism in the wild attempt to "regenerate" the subjective method. All these things show that Comte never really fathomed the distinction between metapliysics and science ; and as the final outcome of all this complicated misconception, we find him, in his famous " Law of the Three Stages," setting forth as the goal of all speculative progress a state or habitude of mind which never has existed and which never can exist. Herein the antago- nism between Cosmism and Positivism becomes so funda- CH. X.] 008MISM AND POSITIVISM. 2G3 mental as to outweigh all minor points of agreement, even were the points of agreement ten times as numerous as they are. For since we deny that the Positive mode of philoso- phizing, implying the recognition of nothing beyond the contents of observed facts, is a practicable mode at all, it is clear that we cannot, save by the utter distortion and per- version of human speech, be classified as Positivists. Casting aside, then, our third and fourth cardinal proposi- tions, temporarily assumed for the purpose of emphasizing this rejection of them, we may briefly restate as follows the fundamental issue between Cosmism and Positivism. We have seen that Comte discerned the fact that there has been a continuous progress in men's conceptions, of which the chief symptom has been deanthropomorphization, and of which the result must be the destruction of ontology. He also discerned the fact, that after giving up ontology, it is still possible to build up a philosophy out of materials furnished by the sciences. We have freely admitted that, in each of these cases, the step taken by Comte was sufficient to work a revolution in the attitude of philosophy ; and we may add that, by virtue of this twofold advance, Comte was justified in calling his system of philosophy " positive," in contrast with the absolutely sceptical or " negative " philo- sophy of the eighteenth century. But, while admitting all this, we have also seen that Comte supposed the terminal phase of deanthropomorphi- zation to consist in the ignoring of an Absolute Power mani- fested in the world of phenomena; and that he regarded philosophy merely as an Organon of scientific methods and doctrines useful in constructing a theory of Humanity and a social Polity. On the other hand, the Cosmic Philosophy is founded upon the recognition of an Absolute Power mani- fested in and through the world of phenomena ; and it consists in a Synthesis of scientific truths into a Universal Science dealing with the order of the phenomenal mani- 264 COSMIC PHILOSOPHY. [pt. i. festatioDS of the Absolute Power. And manifestly these differences between the two systems of philosophy constitute an antagonism which is fundamental and irreconcilable. If the Positivist conception of philosophy be true, then the work which I am now writing is founded upon a baseless metaphysical fallacy; and conversely it is impossible to accept the doctrine expounded in this work, without ipso facto declaring the main position of Positivism to be un- tenable. I shall hereafter have occasion to examine the views con- cerning Psychology, Sociology, Eeligion, and Practice, which are characteristic of the Positive Philosophy; and, as here- tofore, while dissenting from those views in every instance, I shall have no hesitation in acknowledging their merits or in assigning a full meed of homage to the great thinker by whom they were propounded. But while my dissent upon all these points will serve to emphasize and illustrate the fundamental dissent declared in these Prolegomena, it will not be needful again to demonstrate in detail that we are not adherents of the Positive Philosophy. With thrice-reite- rated argument, and at the risk of wearying the reader, it has now been made sufficiently evident that Cosmism and Positivism, far from being identical or identifiable with each other, are in a certain sense the two opposite poles of scientific philosophizing. And in virtue of this demon- strated antagonism, the divergences hereafter to be signalized will appear not merely as easily intelligible but even as d priori inevitable. CHAPTER XI. THE QUESTION STATED. We have now accomplished our preliminary task of defining and illustrating the scope and methods of Cosmic Philosophy, and are prepared to begin the work of constructing a theory of the universe out of the elements which science can furnish. It will accordingly become necessary for us to pass in review the sciences systematized in the eighth chapter, that we may be enabled to contemplate the widest truths which they severally reveal, as corollaries of some ultimate truth. In undertaking this task, there are two opposite courses, either of which we might pursue, though with differing degrees and kinds of success. On the one hand, we might begin with a survey of the concrete sciences ; and having ascertained the most general truths respectively formulated by astronomy, geology, biology, psychology, and sociology, we might interpret all these truths in common by merging them all in a single widest generalization concerning the concrete universe as a whole ; and lastly, through an analysis of this widest generalization we miglit seek the ultimate axiom by which the validity of our conclusions is certified. Or, on the other hand, we might begin by searching directly for this ultimate axiom ; and having found it, we might proceed to deduce from it that widest generalization 266 COSMIC PHILOSOPHY. [ft. i. which interprets the most general truths severally formulated by the concrete sciences ; and finally, by the help of these universal principles, we might perhaps succeed in eliciting sundry generalizations concerning particular groups of concrete phenomena which might otherwise escape our scrutiny. The latter, or synthetic method of procedure, is much better adapted for our present purpose than the former, or analytic method. Indeed the mass of phenomena with which we are required to deal is so vast and so heterogeneous, the various generalizations which we are required to interpret in common are apparently so little related to one another, that it may well be doubted if the appliances of simple induction and analysis would ever suffice to bring us within sight of our prescribed goal. The history of scientific discovery affords numerous illustrations — and nowhere more convincingly than in the sublime chapter which tells the triumph of the Newtonian astronomy — of the comparative helplessness of mere induction where the phenomena to be explained are numerous and complicated. A simple tabulation and analysis of the planetary movements would never have disclosed, even to Newton's penetrating gaze, the law of dynamics to which those movements conform. But in these complicated cases, where induction has remained hopelessly embarrassed, the most brilliant success has often resulted from the adop- tion of a hypothesis by which the phenomena have been deductively interpreted, and which has been uniformly corroborated by subsequent inductions. The essential requisite in such an hypothesis is that it must have been framed in rigorous conformity to the requirements of the objective method. It must be based upon properties of matter or principles of dynamics that have previously been established or fully confirmed by induction ; it must appeal to no unknown agency, nor invoke any unknown attribute of matter or motion ; and it must admit ultimately of inductive CH. XI.] THE QUESTION STATED. 267 verification. Such a hypothesis, in short, is admissible only when it contains no unverifiable element. And of hypotheses framed in accordance with these rigorous requirements, the surest mark of genuineness is usually that they are not only uniformly verified by the phenomena which first suggested them, but also help us to the detection of other relations among phenomena which would otherwise have remained hidden from us. In conformity, then, to these requirements of scientific method, our course is clearly marked out for us. We have first to search, among truths already indisputably established, for that ultimate truth which must underlie our Synthesis of scientific truths. We have next to show how the widest generalization which . has yet been reached concerning the concrete universe as a whole, may be proved to follow, as an inevitable corollary, from this ultimate truth. This widest generalization will thus appear, in the light of our demonstra- tion, as a legitimate hypothesis, which we may verify by showing that the widest generalizations severally obtainable in the concrete sciences are included in it and receive their common interpretation from it. Throughout the earlier part of this special verification, in which we shall be called upon to survey the truths furnished respectively by astronomy, geology, biology, and psychology, I shall follow closely in the footsteps of Mr. Spencer, who has already elaborately illustrated these truths in the light of the Doctrine of Evolution. When we arrive at sociology- — still following Mr. Spencer's guidance, but venturing into a region which he has as yet but cursorily and fragmentarily surveyed for us — I shall endeavour to show that our main hypothesis presents the strongest indications of its genuineness by affording a brilliant interpretation of sundry social phenomena never before grouped together under a general law. This interpreta- tion I shall then seek further to verify by showing how it includes and justifies whatever is defensible in the generaliza- 268 COSMIC PHILOSOPHY. [ft. i. tious which such writers as Comte and Buckle have obtained from an inductive survey of the facts of human history. Finally I shall apply our central hypothesis to the special problem of the Origin of Man, and show how, from its marvellous success in dealing with the difficult questions of intellectual and moral progressiveness, the Doctrine of Evolution must be pronounced to have sustained the severest test of verification which our present scientific resources enable us to apply upon this great scale. With this most significant and interesting inquiry, our Synthesis of scientific doctrines will be completed. Such ultimate questions as must inevitably be suggested on our route — questions con- cerning the relations of the Doctrine of Evolution to Eeligion and Ethics — will be considered, with the help of the general principles then at our command, in the Corollaries which are to follow. At present, however, we are not at the goal, but at the starting-point of this arduous course ; and our attention must first be directed to the search for that ultimate axiom upon which our Synthesis must rest. Where now shall we begin ? In what class of sciences are we to look for our primordial principle ? The above survey of our projected course has already assured us that we need not search for it among the concrete sciences. Obviously the widest proposi- tion which can possibly be furnished by astronomy, or biology, or any other concrete science, cannot be wide enough to underlie a Synthesis of all the sciences. The most general theorems of biology are not deducible from the most general theorems of astronomy ; nor vice versd. But the most general theorems of each concrete science are ultimately deducible from theorems lying outside the region of concrete science. Where shall we find such theorems? If we turn to the purely abstract sciences — logic and mathematics — we shall get but little help. Useful as these sciences are, as engines of investigation, they do not contain what we are now CH. XI.] THE QUESTION STATED. 269 looking for. Obviously mathematics, dealing only witLi relations of number, form, and magnitude, cannot supply the ultimate principle from which may be deduced such pheno- mena as the condensation of a nebula, the segmentation of an ovum, or the development of a tribal commiinity. To build a system of philosophy upon any possible theorem of mathematics, would only be to repeat, after twenty-four centuries, the errors of Pythagoras. And the helplessness of abstract logic, for our purposes, is too manifest to need illustration. Let us then turn to the abstract-concrete sciences ; for in the widest generalizations at which these sciences have jointly arrived we must find, if anywhere, the theorem which we desire. I say "jointly," for in the deepest sense the subject- matter is the same, in molar physics, in molecular physics, and in chemistry. All three sciences deal, in one way or another, with the most general laws of those redistributions of matter and motion which are continually going on throughout the knowable universe. The first deals with the movements of masses ; the second deals with movements of molecules, and with the laws of aggregation of molecules that are homogeneous; the third deals with the laws of aggregation of molecules that are heterogeneous. In either case the phenomena dealt with are movements of matter, whether movements of translation through space, or move- ments of undulation among molecules, or movements whose conspicuous symptom is change of physical state or of chemical constitution. The widest theorems, therefore, which the three abstract-concrete sciences can unite in affirming, must be universal propositions concerning Matter and Motion. Obviously it is in this region of science that we must look for our primordial theorem. But little reflection is needed to convince us that all the truths attainable by the concrete sciences must ultimately rest upon truths relating to the 270 COSMIC PHILOSOPHY. [ft. i movements of matter. It is with the movements, actual or inferred, of certain specific masses of matter, that astronomy in both its branches is concerned. Movements of matter, likewise, in a specific region of the universe, and iinder specific conditions characteristic of this region, constitute the facts about which geologj^ speculates. We need but remember that nutrition is at bottom merely a process in which certain molecules shift their positions, and that the life of an organism is simply a long-continued series of adjustments and readjustments among nmtually-related and mutually-influencing systems of aggregated molecules, in order to see that the fundamental laws of the movements of matter must underlie biology also. And although the phenomena of mind — whether manifested in individuals or in communities — cannot be explained as movements of matter ; yet, as will be hereafter shown, there is no mental phenomenon which does not involve, as its material correlate, some chemical change iu nerve-tissue consisting in a redis- tribution of molecules ; so that in psj^chology and sociology likewise, our conclusions must become ultimately implicated with theorems concerning matter and motion. Thus in every department of concrete science, the leading problem is iu some way or other, either directly or indirectly or very remotely, concerned with distributions and redistributions of matter and motion ; and in all our specific conclusions some^ general conclusion relating to movements of matter must be directly or indirectly or very remotely involved. Our course is thus still more definitely marked out. We must first search for the deepest attainable truth respecting matter and motion abstractly considered. We must pursue this truth and its corollaries, among the most general groups of phenomena in which these corollaries are exemplified, until we arrive at some concrete result concerning the most general aspects of that redistribution of matter and motion which is everywhere going on. And upon this concrete CH. XI.] THE QUESTION STATED. 271 result we shall find that universal generalization to be based, the validity of which we have afterwards to certify by its agreement with inductions drawn from the several groups of phenomena with which the concrete sciences deal. Here, before proceeding further, we may fitly pause for a moment, to relieve a puzzling doubt which may ere this have disturbed the mind of the reader. Did we not elaborately prove, in our opening chapter, that concerning the move- ments of molecules and their aggregation into masses, not only nothing can be known, but no tenable hypothesis can be framed? Did we not, with full knowledge of what we were doing, hang up as the very sign-board of our ippovTLaT'^pLov or philosophy-shop, the proposition that all / that either sense or reason can tell us concerning the inti- mate structure of a block of wood is utterly and hopelessly delusive? Did we not show that the hypothesis of attractive and repulsive forces lands us straightway in an insoluble contradiction ? Did we not find it impossible to get rid of the diiSculties which surround the conception of an atom or a molecule, whether regarded as divisible or as indivisible? And did we not conclude that the conception of matter acting upon matter is a pseud-conception which can by no effort be construed in consciousness ? — Yet in spite of all this, it may be said, we are about to base the entire following Synthesis upon preliminary conclusions relating to the move- ments of molecules and their aggregation into masses ; we are likely to draw inferences from the assumed intimate structure of certain bodies ; we have inevitably to make use of the hypothesis of attractive and repulsive forces ; we shall constantly have tacit reference to the conception of atoms and molecules ; and we shall be obliged to take account of matter as constrained in its movements by other neighbouring matter. Is there not here, it may be asked, a reductio ad absurdum, either of the Synthesis which is to follow, or of the initial arguments upon which the claims of /'■ 272 COSMIC PHILOSOPHY. [pt. i. such a Synthesis to stand for the whole of attainable philo- sophy were partly based ? I state this dilemma as strongly as possible, because it forcibly illustrates the omnipresence of Mystery, — because it shows how, beneath every physical problem, there lies a metaphysical problem whereof no human cunning can detect the solution. Practically, however, the avenue of escape has sometime since been implicitly indicated, — in the fifth and sixth chapters of these Prolegomena. In the chapter on Causation it was shown that, though we can in nowise conceive matter as acting upon matter, yet, for the purposes of common-sense, of science and of philosophy, it is quite enough that one kind of phenomenal manifestation is in- variably and unconditionally succeeded by some other kind of phenomenal manifestation. And in characterizing the Subjective and Objective Methods, we saw that the truth of any proposition, for scientific purposes, is determined by its agreement with observed phenomena, and not by its con- gruity with some assumed metaphysical basis. For example, the entire Newtonian astronomy — the most elaborate and finished scientific achievement of the human mind — rests upon a hypothesis which, if metaphysically interpreted, is simply inconceivable. The conception of matter attracting mattei" through an intervening tract of emptiness is a conception which it is impossible to frame, — and Newton knew it, or felt it to be so. But nowhere did his unrivalled wisdom show itself more impressively than in this, — that he accu- rately discriminated between the requirements of science and the requirements of metaphysics, and clearly saw that, while metaphysics is satisfied with nothing short of absolute subjective congruity, it is quite enough for a scientific hypo- thesis that it gives a correct description of the observed coexistences and sequences among phenomena.^ In truth, * This is distinctly stated by Copernicus; "Neque enim necesse est eas hypotheses esse veras, imo ne verisimile quidem, sed sufficit hoc iinum, si en. XI.] THE QUESTION STATED. 273 for scientific purposes, we are no more required to conceive the action of matter upon matter in the case of gravitation than in any other case of physical causation. All that the hypothesis really asserts is that matter, in the presence of other matter, will alter its space-relations in a specified way ; and there is no reference whatever to any metaphysical occulta vis which passes from matter in one place to matter in another place. There is, however, no good ground for objecting to the use of the phrase " attraction," provided it be employed only as a scientific artifice. There is a certain sense in which science, as well as legal practice, has its " fictions " that are eminently useful. The lines and circles with which geometry deals have nothing answering to them in nature ; and the analyst employs a " scientific fiction " when he deals with infinitesimals, since it is impossible to conceive a quantity less than any assignable quantity. In like manner, tliere is nothing objectionable in using language which assimilates the case of a planet revolving about the sun to the case of a stone whirled at the end of a string ; for there is real similarity between the phenomena. So if the science of chemistry had been obliged to Avait until all the metaphysical difficulties which encompass the conception of a molecule or an atom had been cleared away, it might well have waited until the end of the world. Quite likely the "atom" in chemistiy is as much a " scientific fiction " as the " infini- tesimal " in algebra ; but we cannot therefore complain of the chemist for assigning to it shape and dimensions, pro- vided he makes a scientific and not a metaphysical use of the artifice. In the region of science such a fiction is no more illegitimate than that fiction in the region of common- sense by which I judge this writing-table to be solid, while, for aught I know to the contrary, the empty spaces between calculum observationibus congruentem exhibeaut" — See Lewes, Aristotle, p. 92 ; ProiUms of Life and Mind, vol. i, p. 317. VOL. I. T 274 COSMIC PHILOSOPHY. [rx. i. its particles raay be as much greater than the particles as the interstellar spaces are greater than the stars. We need have no hesitation, therefore, in dealing with the aggregations of atoms and molecules, after the manner of the chemical philosopher, or with attractive and repulsive forces, after the manner of the physicist, so long as we take care that the substance of our propositions has reference only to verifiable coexistences and sequences among phenomena. Another possible difficulty may be now more summarily disposed of. If it be urged that to frame a " generalization concerning the concrete universe as a whole " is manifestly to transgress the limits of sound philosophizing, since we can never know but a tiny portion of the concrete universe, and can never even know how much there is that lies beyond our ken ; if such an objection be urged against the under- taking planned in the present chapter, we may again appeal to ISTewton as witness in our favour. The law of gravitation is expressed in terms that are strictly universal, — terms which imply that wherever matter exists, be it a million times more remote than the outermost limit of telescopic vision, the phenomena of gravitation must be manifested. Comte, indeed, questioned the legitimacy of extending the generalization beyond the limits of the solar systemr But his doubt, which facts so soon refuted, was based on in- adequate knowledge of the psychological aspect of the case. Newton's hypothesis simply detected and generalized the mode of manifestation of one of those properties by virtue of which matter is matter ; and he was justified, according to the principles laid down in our third chapter, in basing a universal proposition upon a single instance. The final test of the presence of matter is the manifestation of the gravitative tendency ; and such must be the case so long as we are unable to transcend experience. As I before observed, it is quite possible that there may be worlds in which numerical limitations like ours are not binding, and so it is CH xi.j THE QUESTION STATED. 275 very possible that there may be worlds in which there is neither matter nor gravity. But any such possible worlds, standing entirely out of relation to our experience, are practically non-existent for a philosophy which is based on the organization of experience. Now, though the law of evolution is not, like the law of gravitation, the generalization of a property of matter, it is still the generalization of certain concrete results of known properties of matter. And the universality which in the following chapters will be claimed for this generalization, is precisely like the universality claimed for the law of gravi- tation. The law of evolution professes to formulate the essential characteristics of a ceaseless redistribution of matter and motion that must go on wherever matter and motion possess the attributes by which we know them. In Mr. Mill's hypothetical world where two and two make five, the law of evolution may not hold sway. But within the limits of our experience, the law is a "generalization concerning the concrete universe as a whole ; " and if it be satisfactorily verified, we shall have achieved that organization of scientific truths into a coherent body of doctrine, which has been shown to be the legitimate aim of Philosophy. Here in conclusion we may again call attention to the significance of the phrase by which I have designated the kind of philosophy that is expounded in this work. We may reiterate the statement, which has already been illustrated from various points of view, that our philosophy is peculiarly entitled to the name of Cosmic Philosophy. For while it may be urged that earlier philosophies have also been cosmic, in so far as they have sought to offer some explanation of the universe, on the other hand it must be acknowledged that never before has the business of philosophy, regarded as a theory of the universe, been undertaken with so clear and distinct a conception of its true scope and limitations. T 2 2V6 COSMIC PHILOSOPHY. [pt. i. Though other thinkers, hefore Mr. Spencer, may have gene- ralized about the concrete universe as a whole, it cannot be denied that he has been the first to frame a verifiable hypo- thesis upon this stupendous scale. The law of evolution is the first generalization concerning the concrete universe as a whole, which has been framed in conscious conformity to the rigorous requirements of the objective method, and which has therefore served to realize the prophetic dream of Bacon, by presenting Philosophy as an organism of which the various sciences are members. Obviously a system which has achieved, or consciously sought to achieve, such a result, is entitled pa7- excellence to the name of Cosmic Philosophy. It has been the first to give practical realization to that sublime thought of two master minds, which I have inscribed at the head of this work : — " To a thinker capable of comprehending it from a single point of view, the universe would present but a single fact, but one all-comprehensiRre truth; and it is for this reason that we call it Cosmos, and not chaos." PAET II. SYNTHESIS. _ Je unyoUkommener das Gesehopf ist, desto mehr sind diese Theile emandergleich Oder ahnlich, „nd desto mehr gleiehen sie dem Ganzen Je vollkommener das Geschopf wird, desto unahnlieher warden die Theile einander. Je ahnlicher die Theile einander sind, desto weniger sind si emander subordanirt. Die subordination der Theile deutet auf eiu yoU kommneres Geschopf. "-Goethe, ^iir^iorpA<,;o<,fe. 1807. CHAPTER I. MATTER, MOTION, AND FOKCE. In the third book of the " Philosophic Positive," Comtc observes that it can hardly be by accident that the word " Physics," which originally denoted the study of the whole of nature, should have become restricted to that science which deals with the most abstract and general laws of the re- arrangement of Matter and Motion. This is one of the many profound remarks scattered through Comte's writings, the full significance of which he could hardly himself have realized.^ For it wUl now appear — as the preceding chapter taught us to expect — that the study of Physics (including under that name, for the moment, the three abstract^concrete sciences) underlies the study of the whole of nature, and discloses those universal truths upon which a Synthesis of the widest truths disclosed by the concrete sciences must repose. It investigates the general phenomena of matter, motion, and force ; while the concrete sciences investigate ' For immediately afterwards we find Comte basing the organic sciences upon physics, but excluding astronomy, which he calls an ' ' emanation from mathematics." It is indeed difiBcult to see how astronomy, which involves the physical ideas of matter, motion, and force, can be an emanation from mathematics, which involves only the purely abstract ideas of space aud number. In fact, as above shown (part i. chap. viii. ), astronomy, no less than the other concrete sciences, is dependent upon physics. Here, as elsewhere, Comte was misled by his serial arrangement. 280 COSMIC PHILOSOPHY. [ft. ii. these phenomena as manifested in particular groups of ag- gregates. The primordial axiom, upon which our synthetic study of the universe must be founded, is one which is dis- closed by the analytic study of the movements of masses and molecules. And thus the three-fold classification of the sciences, by which we found it necessary to replace the simple linear classification of Comte, will find itself practi- cally justified in the very first step which we take toward the organization of scientific truths into a system of Cosmic Philosophy. For at the bottom alike of molar physics, of molecular physics, and of chemistry, there lie, in fact, two universal propositions, — the one relating to Matter, the other relating to Motion. These are the familiar propositions that Matter is indestructille, and that Motion is continuous. Upon the truth of this jiair of closely-related propositions depends the validity of every conclusion to which chemistry or either branch of physics can attain. If, instead of dealing with unalterable quantities and weights, the chemist and physicist "had to deal with quantities and weights which were apt, wholly or in part, to be annihilated, there would be introduced an incalculable element, fatal to all positive conclusions." And since motions of masses and molecules form a prin- cipal part of the subject-matter of the three abstract-con- crete sciences, it is obvious that "if these motions might either proceed from nothing or lapse into nothing, there would be an end to scientific interpretation of thmu;" no science of chemistry, or of physics, molecular or molar, would be possible. The evidence which has secured universal acceptance for these twin theorems has been cliiefly inductive evidence. The ancients -freely admitted that matter might be created and destroyed ; and until the time of Galileo it was sup- posed that moving bodies had a natural tendency to lose their motion by degrees until they finally stopped. Falsify- CH. I.] MATTER, MOTION, AND FORCE. .281 ing many of the complex conditions in the case, the ancients verbally maintained the negations of the theorems that matter is indestructible and motion continuous ; although, if they had tried to realize in thought their crude propo- sitions, they would have found it impossible. But gradually it began to be perceived that in all cases where matter dis- appears — as in the burning of wood or the evaporation of water — the vanished matter has only undergone a mole- cular change which renders it temporarily imperceptible by our unaided senses. Of the manner in which quantitative chemistry has demonstrated this truth, pursuing, balance in hand, the vanished matter through all its protean trans- formations, it is unnecessary to speak. Similar has been the evidence in the case of motion. Observing that, the more effectually friction, atmospheric resistance, and other obstacles to the visible continuance of motion are elimi- nated, the longer the motion continues, the conclusion was reached, by the method of concomitant variations, that if all obstacles could be eliminated the motion would con- tinue for ever. Finally, when it was shown that the ap- parent loss of motion caused by friction is, in fact, only a transformation of a certain quantity of molar motion into its equivalent quantity of that species of molecular motion known as heat, it was admitted on all sides that motion is indestructible, as well aJi matter. But a brief analysis will show that the twin theorems which we are considering have a deductive warrant equally valid with their inductive warrant. Deep as are the truths that matter is indestructible and motion continuous, there is a yet deeper truth implied by these two. These theorems are not fundamental, but derivative ; and it therefore be- comes necessary to ascertain the axiom upon which they depend, since here, if anywhere, must be found the pri- mordial truth which we are seeking. Since we cognize any portion of matter whatever only as 282 COSMIC PHILOSOPHY. [pt. ii. an aggregate of coexistent positions which offer resistance to our muscular energies ; since it is primarily by virtue of such resistance that we distinguish matter from empty space, it follows that our idea of matter is built up of experiences of force, and that the indestructible element in matter is its resisting power, or the force which it exerts. Con- sidering different portions of matter in their relations to each other, we are brought to the same conclusion. When we say that it is chemistry which has proved with the balance that no matter is ever annihilated, we imply that the test of the presence of matter is gravitative force, and that this force is proportional to the quantity of matter. The case of motion is precisely similar. We cognize motion as the successive occupation of a series of positions by an aggregate of coexistent positions which offer resist- ance ; and the essential element in the cognition — " the necessity which the moving body is under to go on changing its position " — has been proved to result from early expe- riences of force as manifested in the movements of our muscles. Consequently, as Mr. Spencer observes, when we find ourselves compelled to conceive motion as continuous, we find that what " defies suppression in thought is really the force which the motion indicates. The unceasing change of position, considered by itself, may be mentally abolished without difficulty. We can readily imagine retardation and stoppage to result from the action of external bodies. But to imagine this, is not possible without an abstraction of the force implied by the motion. We are obliged to conceive this force as impressed in the shape of reaction on the bodies that cause the arrest." Or to put the whole case briefly in another form : — The fundamental elements of our conception of matter are its force-element and its space-element, namely, resistance and extension. The fundamental elements of our conception of motion are its force-element and its space-and-time-element, CH. I.] MATTER, MOTION, AND FORCE. 283 namely, energy and velocity. That in each case the force- element is primordial, is shown by the facts that what we cannot conceive as diminished by the compression of matter is not its extension but its power of resistance ; what we cannot conceive as diminished by the retardation of motion is not its velocity but its energy. Therefore, in asserting that matter is indestructible and that motion is continuous, we assert, by implication, that force is persistent. Our two fundamental theorems are thus seen to derive their validity from a yet deeper theorem, — the proposition that the force manifested in the knowable uni- verse is constant, can neither be increased nor diminished. To this result, which we have here obtained through a general consideration of the problems treated by the abstract- concrete sciences, we. shall be equally led by any special ques- tion of molar physics, molecular physics, or chemistry which we may choose to analyze. When we say that the curve described by a' cascade in leaping from a projecting ledge of rock is a parabola of which the coordinates express respec- tively the momentum of the water and the intensity of gravity at the verge of the ledge ; or when we say that the line followed by any solid body, drawn by two differently situated forces, is the diagonal of a parallelogram of which the sides express the respective intensities of the forces ; the validity of our assertion depends entirely upon the postulate that the forces in question are constant in amount. Annihi- late a single unit of force, and our proposition is hopelessly falsified. Similarly in molecular physics, when we enunciate the formula by means of which Joseph Fourier founded the mathematical theory of heat — namely, the formula that, in all cases of radiation and conduction, the thermological action between two bodies is proportional to the difference of their temperatures — we imply that action and reaction are always equal between the systems of molecules which compose the two bodies. And the equality of action and reaction between 284 COSMIC PHILOSOPHY. [pt. ir. systems of atoms is taken for granted in every proposition of chemistry ; as, for instance, when we say that it will take four molecules of any monatomic substance, like hydrogen, to saturate a single molecule of any tetratomic substance, like carbon. Now to assert the equality of action and re- action, whether between masses, molecules, or atoms, is to assert that force is persistent. " The allegation really amounts to this, that there cannot be an isolated force, beginning and ending in nothing ; but that any force manifested, implies an equal antecedent force from which it is derived, and against which it is a reaction. Further, that the force so originating ' DO cannot disappear without result ; but must expend itself in some other manifestation of force, which, in being produced, becomes its reaction ; and so on continually." ^ Clearly, therefore, the assertion that force is persistent is the funda- mental axiom of physics : it is the deepest truth which analytic science can disclose. But now what warrant have we for this fundamental axiom ? How do we know that force is persistent ? If force is not persistent, if a single unit of force can ever be added to or subtracted from the sum-total at any moment existing, our entire physical science is, as we have seen, a mere delusion. In such case, it is a delusion to believe that action and reaction are always equal, that the strongest bow, bent by the strongest muscles, will always send its arrow to the greatest distance if otherwise unimpeded ; it is a delusion to believe that the pressure of the atmosphere and its tem- perature must always affect the height of enclosed columns of alcohol or mercury, or that a single molecule of nitrogen wiU always just suflice to saturate three molecules of chlo- rine. And, this being the case, our concrete sciences also fall to the ground, and our confidence in the stability of nature is shown to be baseless ; since for aught we can say to the contrary, the annihilation of a few units of the earth's ' SpBJicer, First Principles, p. 188. CH. I.] MATTEB., MOTION, AND FORCE. 285 centrifugal force may cause us to fall upon the svin to- morrow. But how do we know that all science is not a delusion, since there still exist upon the earth's surface persons who will tell us that it is so ? Why do we so obstinately refuse to doubt the constancy of the power manifested in nature ? What proof have we that no force is ever created or destroyed ? Logically speaking, we have no proof An axiom which lies below all frameable propositions cannot be deductively demonstrated. Below the world stands the elephant on the back of the tortoise, and if under the tortoise we put the god Vishnu, where is Vishnu to get a foothold ? Nor can our axiom be demonstrated inductively, without reasoning in a circle. We cannot adduce the observed equality of action and reaction in proof of the persistence of force, because this persistence is taken for granted in every observation by which the equality of action and reaction is determined. Obviously it is impossible to prove the truth of an axiom by any demonstration in every step of which the truth of the axiom must be assumed. But these results need not surprise or disturb us. As we saw, when discussing the Test of Truth, the process of demonstration, which consists in continually "merging derivative truths in those wider and wider truths from which they are derived," must eventually reach a widest truth, which cannot be contained in or derived from any other. At the bottom of all demonstration there must lie an \ indemonstrable axiom. And the truth of this axiom can j only be certified by the direct application of the test of '• inconceivability. We are compelled to believe in the per- sistence of force, because it is impossible to conceive a variation in the unit by which force is measured. It is impossible to conceive something becoming nothing or nothing becoming something, without establishing in thought an equation between something and nothing; and this 280 COSMIC PHILOSOPHY. [pt. ii. cannot be done. That one is equal to zero is a proposition of which the subject and predicate will destroy each other sooner than be made to unite. Thus the proof of our fundamental axiom is not logical, but psychological. And, as was formerly shown, this is the strongest possible kind of proof. Inasmuch as our capacity for conceiving any proposition is entirely dependent upon the manner in which objective experiences have registered themselves upon our minds, our utter inability to conceive a variation in the sum-total of force implies that such varia- tion is negatived by the whole history of the intercourse between the mind and its environment since intelligence first began. The inconceivability-test of Kant and the experience-test of Hume, when fused in this deeper synthesis, unite in declaring that the most irrefragable of truths is that which survives all possible changes in the conditions under which phenomena are manifested to us. The persistence of force, therefore, being an axiom which survives under all conditions cognizable by our intelligence, being indeed the ultimate test by which we are compelled to estimate the validity of any proposition whatever concerning any imagin- able set of phenomena and under any conceivable circ\im- stances, must be an axiom necessitated by the very constitu- tion of the thinking mind, as perennial intercourse with the environment has moulded it. Mr. Mill, indeed, in his " System of Logic," Book iii. Chap, xxi., maintains that our belief in the necessity and universality of causation (which was above shown ^ to be an immediate corollary from the persistence of force) rests upon an induc- tion per enumerationem simpliceni, which is, however, valid in this one case, because it is coextensive with all known orders of phenomena. The incompleteness of this view is shown by the fact that the persistence of force is necessarily assumed in eveiy step of the vast induction by which the ' See above, part i. chap, vi. cii. I.J MATTER, MOTION, AND FORCE. 287 law of causation is said to be established. Mr. Mill only emphasizes the incompleteness of his view when he repudiates the inconceivability-test as evidence of the law in question. This point has been already so fully discussed that little more need to be said about it here. When, in a future chapter, we come to deal especially with the evolution of intelligence, we shall see that Mr. Mill's inadequate treat- ment of this subject is due to imperfect mastery of the Doctrine of Evolution. "We shall see that the so-called experience-philosophy is both wider and deeper than English psychologists, from Hobbes to MiU, have imagined. We shall see that not only our acquired knowledge, but even the inherited constitution of our minds, is the product of accumulated and integrated experiences, partly personal but chiefly ancestral. Upon this wider ground we shall find ourselves able to dwell in peace with our old foes, the intuitionalists, since it will be seen that the very intuitions upon which they rightly insist as inexplicable from individual experience are nevertheless explicable from the organized experiences of countless generations. And the conclusion will then assert itself, with redoubled emphasis, that the axiom of the persistence of force, being the product of the entire intercourse between subject and object, since the dawn of intelligence, must have the highest warrant which any axiom can have. Let us for the present, however, content ourselves with reproducing the psychological argument by which Mr. Spencer clinches his demonstration of the necessity which we are under to conceive of force as persistent. " The inde- structibility of matter and the continuity of motion, we saw to be really corollaries from the impossibility of establishing in thought a relation between something and nothing. What we call the establishment of a relation in thought, is the passage of the substance of consciousness from one form into another. To think of something becoming nothing, would 288 COSMIC PHILOSOPHY. [p^- n. involve that this substance of consciousness, having just existed under a given form, should next assume no form; or should cease to be consciousness. And thus our inability to conceive matter and motion destroyed, is our inability to sup- press consciousness itself. What is thus proved true of matter and motion is d fortiori true of the force out of which our conceptions of matter and motion are built." Thus we see it is the persistence of consciousness itself which imposes on us the necessity of asserting the persistence of force. And accordingly this primordial axiom being involved in every act of conscious thinking, and being the basis of experience, "must be the basis of any scientific organization of experi- ences. To this an ultimate analysis brings us down ; and on this a rational synthesis must build up." The force of these considerations will become still more strikingly apparent as we proceed to contemplate the most general corollaries of this fundamental axiom with which the science of physics has furnished us. The first of these corollaries is the theorem that the relations among forces are persistent. That is to say, in all cases an aggregate of like causes will be followed by an aggregate of like effects. " If in any two cases there is exact likeness not only between those most conspicuous antecedents which we distinguish as the causes, but also between those accompanying antecedents which we call the conditions, we cannot affirm that the effects will differ, without affirming either that some force has come into existence or that some force has ceased to exist. If the cooperative forces in the one case are equal to those in the other, each to each, in distribution and amount ; then it is impossible to conceive the product of their joint action in the one case as unlike that in the other, without conceiving one or more of the forces to have increased or diminished in quantity ; and this is conceiving that force is not persistent."! It follows, therefore, from the persistence ' First Principles, p. 193. OH. 1.] MATTER, MOTION, AND FORCE. 289 of force, that there is an invariable order of succession between the totality of phenomena which exist at any given instant and the totality of phenomena which exist at the next succeeding instant. No matter how many special orders of sequences may interlace to form the grand web of sequent phenomena, the order of sequences, both separately and in the aggregate, must be invariable. In complicated mechanical problems, where many forces are involved, we proceed to eliminate one after another by means of the principle of the parallelogram of forces, until at last we retain but two differently located forces, the resultant of which is easily calculable. So, in the most complex cases of causation to be found in nature — as, for instance, in those concerned in the development of the moral character of individuals — if we possessed the means of measuring quantitatively the ratio of each set of antecedents to its set of consequents, we might eliminate one group after another, until at length a necessary relation of sequence would be disclosed between the resultant group of antecedents and consequents. As Mr. Mill observes : " For every event there exists some combination of objects or events, some given conciirrence of circumstances, positive and negative, the occurrence of which is always followed by that phenomenon. We may not have found out what this concurrence of circumstances may be ; but we never doubt that there is such a one, and that it never occurs without having the phenomenon in question as its effect or con- sequence." ' Our unhesitating assurance that " there is a law to be found if we only knew how to find it " is thus the foundation of all the canons of inductive logic. The uniformity of the laws of nature is elsewhere called by Mr. Mill "the major premise of all inductions." The present analysis further shows us that this uniformity of law is resolvable into the persistence of relations among forces, and is therefore an immediate corollary from the persistence of force. 1 System of Logic, 6tli edit., vol. i. p. 867. VOL. I. U 290 COSMIC PHILOSOPHY. [^t. n- Besides this purely philosophical corollary from our fundamental axiom, we have to note three other corollaries, •which, as belonging to the transcendental regions of physical science, must be set forth and illustrated before we can profitably begin our synthesis of scientific truths. Let us briefly consider these in their natural order. The first of these corollaries is the generalization currently known as the " Correlation of Forces." Since each mani- festation of force must have been preceded by some other equivalent manifestation of force, it follows that when any specific manifestation appears to terminate, it does not really cease to exist, but is only transformed into some other specific manifestation. That we may better apprehend this important truth, let us clear away some of the ambiguity which surrounds the terms commonly employed in the statement of it. The phrase " correlation of forces," which means the correlation of sensible motion with heat, light, electricity, etc., implies that heat, light, and electricity are forces. This is not strictly accurate. Heat and light are modes of undulatory motion, and electricity, with its kindred pheno- mena, is to be similarly interpreted. Now motion is not force, but one of the manifestations of force ; and so the various modes of motion, molar and molecular, are differently conditioned manifestations of force. The force which pro- duces or resists motion is known by us only under the twofold form of attraction and repulsion, which may be either polar or universal. Polar attraction or repulsion is that which acts with different power in different directions. An example of polar attraction is to be found in every case of crystallization, where molecules are grouped into a solid figure bounded by plane surfaces ; and a familiar example of polar repulsion is that which is exhibited when the positive poles of any two magnets are brought into mutual proxi- mity. Universal attraction or repulsion is that which CH. I.J MATTER, MOTION, AND FORCE. 291 acts with equal power in all directions. In universal attraction we are accustomed to distinguish three modes, respectively called gravity, cohesion, and chemism or chemical affinity. The essential difference hetween these modes of primary force and the various modes of motion, is illustrated by the familiar facts that gravity causes molar motion while molar motion does not cause gravity ; and that chemism gives rise to the species of molecular motion called heat, while heat cannot give rise to chemism, though it may result in a mole- cular rearrangement which will allow chemism to manifest itself. For example gravity ca\ises a spent rocket to fall to the ground ; but the upward motion of the rocket does not cause gravity, although it results in a position of the rocket which enables gravity to reveal itself by causing downward motion. So when nitrous oxide is decomposed into nitrogen and oxygen, a considerable amount of heat is evolved ; but when all this thermal undulation is restored under appropriate conditions, and the compound is again formed, it is not that the thermal undulation gives rise to the chemism which draws the atoms of nitrogen and oxygen together ; it is only that the thermal undulation results in such a redistribution of the atoms that their progress toward each other is un- impeded, and thus the latent force of chemism is revealed. Now the law of the correlation of forces, which perhaps ought rather to be called the law of the transformation of motion, is simply the obverse of that corollary from the per- sistence of force, which affirms that whatever energy has been expended in doing -woA must reappear as energy. The energy of molar motion which disappears when an arrow sticks in its target is really transformed into the energy of molecular motion which is recognized partly as heat and partly as electricity. That the different modes of motion are transformable into each other, is now one of the common- places of physical science, and needs but little illustration u 2 292 COSMIC PHILOSOPHY. [p^- "• here. What is called the arrest of motion by friction is now known to be the change of molar motion into heat, when the rubbing substances are alike in constitution, — into heat and electricity, when they are unlike. In violent collisions, as in the chipping of stones with a mason's chisel, the arrested molar motion is partly changed into light. And when an iron bar is suspended in the magnetic meridian and violently struck or continually jarred, a portion of the arrested motion reveals itself as magnetism. The transformation of heat into molar motion may be seen in the rise and fall of the mercury in the thermometer, or in the driving of a piston by the molecular dilatation of aqueous vapour. When lime is introduced into an atmo- sphere of burning hydrogen, we see the conversion of heat into light. And when the heated ends of zinc and copper wires are brought together, we see heat generating electric currents. Conversely, electricity conducted down a light- ning-rod is partly converted into heat; and in the bright flashes which are followed by claps of thunder, we witness electric energy partly consumed in originating light. The phenomenon commonly called light is but a species of a mode of solar energy which may be called radiance or actinism, and which, according to the manner in which it affects our senses, is known as radiant heat, as light, or as the energy which works changes in the daguerreotype-plate and in the leaves of plants. The difference between the higher rays of the solar spectrum, which manifest them- selves chiefly in causing chemical changes, and the lower rays, which are cognized as violet light, is generically the same as the difference between these and the still lower rays which are cognized as indigo, blue, green, yellow, orange, or red light; and the same is true if we descend to those still lower rays which are recognized only by their thermal effects. If we call the energy manifested in the solar beam by the general name of actinism, we may say CH. I.] MATTER, MOTION, AND POBOE. 293 that actinism is transformable into all the other modes of motion. In Mr. Grove's celebrated experiment, where a daguerreotype-plate is ingeniously connected with a galvano- meter, a gridiron of silver wire, and a heat-registering helix, and where actinism is the initial mode of motion, there are obtained " chemical action on the plate, electricity in the wires, magnetism in the coil, heat in the helix, and [molar] motion in the needles." In all cases where the disappearance of any given mode of motion is followed by the appearance of some other mode, the proof that there has been an actual transformation of the former mode into the latter is of two kinds. Deductive proof is furnished by the fact that the only alternative sup- position is unthinkable, — namely, the supposition that the one kind of motion has been annihilated, while the other kind has been created for the occasion. Inductive proof is furnished by the fact that wherever it is possible to measure both the amount of motion that disappears and the amount that appears in its place, the two quantities are always found to be equal. Thus the molar motion implied in the fall of 772 pounds of matter through one foot of space, will always raise the temperature of a pound of water just one degree of Fahrenheit. And similar quantitative correlations have been established among other modes of motion. The second corollary from the persistence of force asserts that the direction of motion in any case is always the resultant between the lines representing respectively the greatest traction and the least resistance exerted by the forces upon which the motion depends. In any plexus of forces whatever, the resultant of all the tractive forces in- volved wiU be the line of greatest traction ; the resultant of all the resisting forces will be the line of least resistance ; and the direction of motion in the resultant of this final pair of resultants follows directly from the persistence of force. 294 COSMIC PHILOSOPHY. [ft. n- For the last resultant represents the direction and amount of a surplus force which remains after all the other forces have been equilibrated ; and to assert that this force will not be manifested in motion along this line, is to assert that force may be expended without effect. Still more obvious does this become, when we remember that " our only evidence of excess of force is the movement it produces." Since we know force not in itself, but only as revealed to conscious- ness in matter and motion, it follows that motion in any direction is the only proof we have that there is a surplus of unantagonized force acting in that direction. So that our theorem becomes almost an identical proposition. But if we ask why the greater of two opposing forces is that which causes motion in its own direction, there can be no answer save the one already given. There is no warrant save the consciousness that the unneutralized surplus of force cannot cease to act. The simplest case contemplated by this corollary is that of a moving body left to itself. There being here no force involved, save the body's own momentum, the direction of motion is an infinite straight lice. But since the realization of such a case would involve the annihilation of all matter save the body in question, it is obvious that no such simple case can ever have existed within the limits of the knowable universe. The simplest case of motion which can come within our cognizance is really complex to a degree which baffles computation. Mr. Spencer somewhere remarks that when a man appears to be walking westward, he is really being carried eastward by the earth's rotation at the rate of 1,000 mUes an hour. Besides this, the earth's orbital motion is carrying him westward at the differential rate of 67,000 miles an hour. Meanwhile the motion of the solar system toward the constellation Hercules is all the time bearing him in a direction neither east nor west. While, if we could comprehend in a single view the dynamic relations of the CH. I.] MATTER, MOTION, AND FORCE. 295 entire sidereal -universe, we should find that even the enormous factors already taken into the account would help us but little toward determining the resultant direction in which the man is moving. The comparative ease with which astronomy ascertains the direction of the motions with which it deals, is due to our ability to isolate our- selves theoretically from an indefinitely extended universe of environing bodies ; and this is due to the principle, esta- blished by Galileo, that the relative motions of the parts of an aggregate are not affected by the motion of the whole. If we could include in the problem the entire knowable universe, we should doubtless find the real motions of a planet as impossible to calculate mathematically as are now the motions of a corpuscle of nerve-substance when thrown out of equilibrium by an act of thinking. Nevertheless, because of this principle that the relative motions of parts may be calculated independently of the motion of the whole, we are enabled legitimately to restrict our views, so that motion along the resultant of two or three forces may be determined and predicted with a near ap- proach to accuracy. Witness the ease with which we can calculate the orbit of a comet. But when the forces become more numerous, it becomes impossible to determine their resultant. Witness the excessive difficulty of predicting the direction of currents in the atmosphere. The movements of organisms still more hopelessly bafile our powers of calcula- tion. It is hardly probable that science will ever obtain equations for the motions of a lion in securing his prey ; yet that would be a very shallow philosophy which should seek to assure us that each one of those motions does not take place along the resultant of all the forces involved. To an intelligence sufficiently vast, the motions of the earth in space would doubtless seem as complicated as those of the lion seem to us. But no amount of complexity can alter the fundamental principle that the direction of motion must 296 COSMIC PBILOaOPH Y. [ft. ii. be the resultant between the lines of greatest traction and of least resistance. In conclusion let us observe that in many cases the total amount of traction is so small compared to the total amount of resistance, that for practical purposes it may be neglected ; and vice versd. Thus, when a meteor falls upon the earth, we may neglect the resistance of the atmosphere, and say that the meteor follows the line of greatest traction; and ■when a volcano throws up a column of lava, we may neglect the effects of gravity, and say that for the time being the lava follows the line of least resistance. We shall thus, without any considerable inaccuracy, avoid cumbrous verbiage; and in the case of molecular motions propagated through masses of matter, with which our exposition is chiefly concerned, it is sufficiently accurate to say that motion follows the Une of least resistance. CHAPTEE II. RHYTHM. The third corollary from the persistence of force may best be introduced by a reconsideration of the simplest case of motion contemplated by the preceding corollary. The reali- zation of Galileo's first law of motion — the law that a moving body must for ever continue in a straight line with uniform velocity — obviously postulates the non-existence of any other matter than that contained in the body in ques- tion. If there were but one body in the universe, that body, when once set in motion, would never alter its direction, or undergo any increase or diminution of velocity. The intro- duction of a second body, attracting the first and attracted by it, alters the result in a way which now demands brief consideration. If the motion with which the two bodies start is such as would carry them along a straight line toward each other, they miist obviously rush together, and the case is thus again reduced to that of a single moving body. But this case is too simple to have been ever actually realized. What we have to deal with is the case of two bodies which are moving in independent directions. For the sake of simplicity, let us suppose that the second body, B, is so much heavier than the first body. A, that the common centre of gravity of the two lies within b's peri- 298 COSMIC PHILOSOFHY. [ft. ii. phery. What now will be the result ? The direction of a's motion, instead of remaining unaltered, will be at each instant deflected from a straight line in such a way that A will continually approach nearer and nearer to a point some- where in advance of B, upon the line in which B is moving : instead of a straight line we shall have a curve of which the coordinates will bear to each other a ratio equal to the ratio between A's momentum and b's tractive force. The velocity of A will also cease to be uniform. Por as soon as A has passed on beyond B, a portion of its momentum will be at each in- stant consumed in neutralizing b's tractive force, so that the velocity due to the remaining momentum, will be at each instant diminished. Now, unless a's momentum be infinite, this process cannot go on for ever. By the time that a has arrived at the point directly in advance of b, so much momentum will have been lost that b's attraction will begin to overbalance it, and the curve in which A is moving will begin to turn back toward b. But now b's tractive force begins to augment at each instant the velocity of a, until, by the time that A has reached a position alongside of B, its momentum is considerably in excess of B's attrac- tion, and it is consequently carried on toward a point in the rear of B. The same rhythmical decrease and increase in A's momentum continues until the curve is completed, and A has reached the position from which it started. Thus our attracted body, instead of moving in a straight line, moves in a closed curve of which one of the foci must coincide in position with the common centre of gravity of the attracted and attracting bodies. The result which we have here obtained by supposing a to be so much smaller than B that its reciprocal influence upon b's motion might be left un- considered, is not altered if we suppose A and B to be equal in size. In this case the common centre of gravity lies mid- way between the two bodies, and is the common focus of the two closed curves respectively described by them. CH. n.] UHYTHM. 299 The illustration is a very trite one, being approximately realized in every case of planetary revolution, but the space here given to it is justified by the supreme importance of the principle now to be generalized from it. To Galileo's first law of motion there is now to be added a supplemental law. As a single moving body, in an otherwise empty universe, would move for ever with unvarying velocity in an unvary- ing direction ; so, on the other hand, two or more bodies, moving in independent directions and exerting attractive forces upon each other, must for ever move in directions which rhythmically vary, and with velocities which are rhythmically augmented and diminished. Thus the rhythm of motion is a corollary from the persistence of force. Our only alternatives are rhythm, or invariable velocity in an invariable direction. The latter alternative being excluded by the fact that in the known universe innumerable bodies coexist, it follows that we must adopt the former, and admit that all motion is and must be rhythmical. The direct dependence of this conclusion upon the axiom of the persistence of force is still further illustrated by the case of the pendulum. Let us imagine, for the sake of definiteness, a heavy bob at the end of a rigid wire. When the bob is raised to leftward of the perpendicular, and then left to the action of gravity, it at once begins to descend. But while it is descending, gravity is at each instant adding to its momentum, so that, when it reaches the perpendicular, it cannot stop, but is carried along to rightward until all the added momentum is lost again ; that is, until it has ascended to a height equal to that from which it began to descend. Being now left to the unhindered action of gravity, the same series of motions will occur in the reverse direction, and so on for ever. Strictly speaking, no such case can be realized ; since all the lost momentum is not expended in neutralizing gravity, but part of it is employed in communi- cating motion to the environing atmosphere, and part of it is 300 COSMIC PHILOSOPHY. [pt. ii. transformed into lieat. But if all the molar momentum thus dissipated could be retained, the rhythmic motion of the pendulum would continue for ever. But why ? Simply because the momentum acquired during the descending rhythm cannot cease to manifest itself, save as it is neu- tralized during the ascending rhythm. And to adduce this reason is to appeal directly to the persistence of force. The case of undulatory motions propagated among the molecules of matter, is precisely similar. The passage of an undulation implies at each instant a momentary local rarefaction, followed by a momentary local condensation. At a given instant certain molecules are removed further from each other, while at the next succeeding instant they approach each other, and the molecules immediately adjacent are removed from each other. Why is rarefaction thus suc- ceeded by condensation ? What is it that determines the rebound of the disturbed molecule towards its original posi- tion ? Obviously the progress of a pair of molecules toward positions farther and farther from each other is opposed by the inertia of adjacent molecules, which these push before them as they advance. The local rarefaction is achieved only at the expense of an adjacent condensation. This condensation of the adjacent molecules increases their elas- ticity until it begins to overbalance the momentum of the separating pair of molecules, and then these molecules are driven back toward each other. And so on, without inter- mission. Now the recoil of the advancing molecule is necessitated by the fact that the elasticity which it generates in the resisting molecule cannot expend itself without pro- ducing motion. And to say this is to recur again to our fundamental axiom. Thus in all cases, whether molar or molecular, the rhythm of motion is necessitated by the fact that in a multiform universe no portion of matter can move uninfluenced by some other portion. The illustrations just given do biit cii. 11.] RHYTHM. 301 typify that which is for ever going on througliout the length and breadth of the Cosmos. Periodicity, rise and fall, re- currence of maxima and minima, — this is the law of all motions whatever, whether exemplified by the star rushing through space, by the leaf that quivers in the breeze, by the stream of blood that courses through the arteries, or by the atom of oxygen that oscillates in harmony with its companion-atoms of hydrogen in the rain-drop. Always, as in our initial illustration, the forces which are carrying a given portion of matter in a given direction become gradu- ally altered in their distribution, and in their amounts, until the direction of the motion becomes practically reversed; and whether the given portion of matter be a planet or a molecule, the dynamic principle remains the same. Just as Newton's law of inverse squares applies to molecules as well as to masses, so the law of rhythm applies in both cases. Thus what we may call the elementary motions going on throughout the world of phenomena — the elementary motions by the various combinations of which all percep- tible motions are made up — are all rhythmical or osciLlatory. The phenomena which are presented to our consciousness as light, heat, electricity, and magnetism, are the products of a perpetual trembling, or swaying to and fro of the invisible atoms of which visible bodies are composed. When we contemplate the heavens on a clear autumn evening, and marvel at the beauty of Sirius, that beauty is conveyed to our senses through the medium of atomic shivers, kept up during the past twenty-two years, at the average rate of six hundred millions of millions per second. The difference between the tropical heat of India and the cold of the Arctic regions is simply the measure of untold millions of tiny differences in the rates of oscillation of countless atoms of atmospheric gases, determined in turn by innumer- able oscillatory movements propagated from the sun to the earth. The difference between the faradaic current which 302 COSMIC PHILOSOPHY. [pt. n. cures some deep-seated abnormity of nutrition, and the lightning-flash which paralyzes and kills, is at bottom a difference in amounts and rates of atomic vibration. And ■according to the latest speculations in chemical philosophy, it is because of the synchronousness or rhythmical harmony of the oscillatory movements described by their atoms, that elementary substances are enabled to combine in myriadfold ways, thus making up the wondrous variety of forms, organic and inorganic, which the earth's surface presents for our contemplation. Since the ultimate particles of which science regards the universe as composed are thus perpetually swaying to and fro, in accordance with a law of motion that admits of no exception, we may expect to find that the various aggregates of these particles which constitute perceptible bodies will exhibit a like rhythm, whether comparatively simple or endlessly compounded, in their motions. The law which governs the action of the parts must govern also the action of the whole, no matter how intricately the whole may be compounded. Whether it be in the case of organic or in- organic bodies, of complex or of simple aggregates, we must expect to come upon systems of rhythmical movements, which will be comparatively simple or endlessly complex, according to the structural complication of the bodies in question. Let us exhibit a few instances of this rhythmical action, before we pass to the stupendous consequences of the theorem which I have been endeavouring to elucidate. Some of the chief instances to be gathered from astronomic phe- nomena have been so admirably presented by Mr. Spencer, that I cannot do better than to quote in full his concise statement. Along with the planetary revolutions which furnish the illustration with which I began this chapter, "the solar system presents us with various rhythms of a less manifest and more complex kind. In each planet and satellite there CH. II.] RHYTHM. 303 is the revolution of the nodes — a slow change in the position of the orbit-plane, which after completing itself commences afresh. There is the gradual alteration in the length of the axis major of the orbit ; and also of its eccentricity ; both of which are rhythmical alike in the sense that they alternate between maxima and minima, and in the sense that the progress from one extreme to the other is not uniform, but is made with fluctuating velocity. Then, too, there is the revolution of the line of apsides, which in course of time moves round the heavens — not regularly, but through com- plex oscillations. And further we have variations in the directions of the planetary axes — that known as nutation, and that larger gyration which, in the case of the earth, causes the precession of the equinoxes. " These rhythms, already more or less compound, are compounded with each other. Such an instance as the secular acceleration and retardation of the moon, consequent on the varying eccentricity of the earth's orbit, is one of the simplest. Another, having more important consequences, results from the changing direction of the axes of rotation in planets whose orbits are decidedly eccentric. Every planet, during a certain long period, presents more of its northern than of its southern hemisphere to the sun at the time of its nearest approach to him ; and then again, during a like period, presents more of its southern hemisphere than of its northern — a recurring coincidence which, though causing in some planets no sensible alterations of climate, involves in the case of the earth an epoch of 21,000 years, during which each hemisphere goes through a cycle of temperate seasons, and seasons that are extreme in their heat and cold. ISTor is this all. There is even a variation of this variation. For the summers and winters of the whole earth become more or less strongly contrasted, as the eccentricity of its orbit increases and decreases. Hence during increase of the eccentricity, the epochs of moderately contrasted seasons 304 COSMIC PHILOSOPHY. [pt. ii. and epochs of strongly contrasted seasons, through which alternately each hemisphere passes, must grow more and more different in the degrees of their contrast : and con- trariwise during decrease of the eccentricity. So that in the quantity of light and heat which any portion of the earth receives from the sun, there goes on a quadruple rhythm : that of day and night ; that of summer and winter ; that due to the changing position of the axis at perihelion and aphelion, taking 21,000 years to complete; and that involved by the variation of the orbit's eccentricity, gone through in millions of years." ^ The astronomic rhythms here enumerated are peculiarly interesting from the fact that, owing to their comparatively simple character, they are susceptible of mathematical treat- ment, so that their direct dependence on the principle of the persistence of force can be quantitatively demonstrated. In ascending to the order of phenomena next above them in point of complexity — the geologic phenomena occurring on the earth's surface — we enter a region where such quantita- tive proof, save of a very crude sort, cannot be obtained. The great complexity of geologic as contrasted with astro- nomic rhythms is shown by the fact that whereas on the one hand, we can readily calculate the variations of eccentri- city in the earth's orbit which have taken place during millions of years gone by or which are sure to take place during millions of years to come, on the other hand we are not yet able to assign an approximate date for the most recent epoch at which our northern hemisphere was covered with glaciers. According to Mr. Wallace this epoch may have occurred no more than seventy thousand years ago, while others would assign to it an antiquity of at least two hundred thousand years, and there are yet others who urge strong arguments in behalf of the opinion that a million of years is barely enough to have produced the changes which ' First Principles, pp. 256, 257. CH. II.] RHYTHM. 305 have taken place since that event. Nevertheless, though we cannot determine the amounts and durations of the move- ments which have occurred during the geologic history of the earth, we can still securely assert that these movements have been rhythmical in character. Though the verdict is rendered with less precision, its purport is still the same. In the alternating periods of elevation and depression which have succeeded each other at different places ever since the earth's crust began to be solidified, are exemplified the chief geologic rhythms, due to the slow deflection of the lines of least resistance along which the pressure of the earth's nucleus reveals itself by causing upward motion. But these immensely long rhythms are complicated by minor rhythmical changes of surface, due to continual shifting of river-beds and consequent variations in the areas of denu- dation and in the deposit of sedimentary strata. And these rhythms are still further complicated by rhythmic variations in the operation of climatic agencies, entailing periodic changes in the amount and distribution of rainfall, in the size and movements of icebergs and glaciers, and in the activity of frost. On the sea-shore we may witness the compound rhythm of the tides, "in which the daily rise and fall undergo a fortnightly increase and decrease, due to the alternating coincidence and antagonism of the solar and lunar attractions " ; a source from which arise the most minute geologic rhythms, as those which arise from the secular cooling of the earth, and from its ever varying position in space, are the most vast. But the subject of complex rhythms is still better illus- trated in biology. The commonest physiological act, such as eating, is dependent upon a periodically occurring sensation of hunger, due to a periodic excess of waste over repair. The taking of nutriment is accomplished, in all animals, by a series of rhythmical motions, — either the motions of cilia, or of sphincter muscles, or of jaws, or indeed, of all three at VOL. I, X 306 COSMIC JfBILOSOPHY. [vr. u. once. Mr. Spencer adds that "the swallowing of food is effected by a wave of constriction passing along the oeso- phagus ; its digestion is accompanied by a muscular action of the stomach that is also undulatory ; and the peristaltic motion of the intestines is of like nature. The blood obtained from this food is propelled not in a uniform current but in pulses; and it is aerated by lungs that alternately contract and expand." To this we may add that assimilation is a continuous process of rhythmic interchange between the molecular constituents of the various tissues and of the blood by which they are bathed; that muscular action is the result of a series of oscillatory movements ; and that nervous action depends upon a quickly alternating rise and fall in the chemical instability of the molecules which compose the nerve-centres. All these minor rhythms are as ripples upon the surface of the longer rhythm constituted by sleep and wakefulness. Eecent researches have shown that sleep itself furnishes a beautiful illustration of the manner in which rhythm is necessitated by the continual redistribution of forces in the organism. According to the most recent view, sleep is caused by a diminution in the capacity of the cerebral arteries, which lessens the circulation of blood through the brain. It is the sympathetic nerve which effects this contraction of the arteries. During the day the activity of the cerebrum itself supplies the stimulus which causes arterial blood to flow through the head in large quantities, so as to keep the vessels duly distended. But after many hours of activity the ratio of repair to waste is sensibly diminished ; there is a fall in the average chemical instability of the cerebral nerve-molecules, and a consequent diminution in the amount of cerebral stimulus ; until presently the amount of stimulus sent up from moment to moment along the cervical branch of the sympathetic nerve exceeds the amount which the cerebrum can oppose to it. Experiment has shown that the effect of stimulating the sympathetic nerve is to contract cii. II.] liHYTHM. 307 the muscular walls of the cerebral arteries. The supply of arterial blood is thus so far diminished that consciousness ceases. But now the other half of the rhythm begins. The cessation of conscious activity greatly diminishes the waste of cerebral tissue ; and, although repair is also somewhat lessened by the lessened blood-supply, yet the ratio of repair to waste is increased. The complex nerve-molecules are built up to higher and higher grades of instability, until it only needs a slight stimulus from without, in the shape of a sensation of sound or of light or of touch, to elicit a discharge of nerve-force from the cerebral ganglia. This discharge is instantly answered by a rush of blood, which distends the cerebral arteries, revives consciousness, and holds in abeyance the contractile energy of the sympathetic nerve, until the decreasing ratio of repair to waste by and by necessitates a recurrence of the rhythm. Thus the alternation of sleep and wakefulness is due to a periodic variation in the ratio between the amount of nerve-force stored up in the cerebrum and the amount stored up in the sympathetic ganglia. We recognize this truth in practice when we seek to induce sleep by stimulating the sympathetic nerve with such substances as bromide of potassium. The phenomenon of sleep is still further interesting as the moat familiar instance of the dependence of biologic rhythms upon astronomic rhythms. All organisms, animal and vegetable, from the highest to the lowest, exhibit alterna- tions in the total distributions of their forces, which coincide with the periodic appearance and disappearance of sunlight. The longer astronomic rhythm, known as the earth's annual revolution, causes corresponding rhythms in vegetable and animal life; witness the blossoming and leafing of plants in the spring, the revival of insect activity at the same season, the periodic flights of migratory birds, the hyber- nating sleep of many vertebrates, and the thickened coats or the altered habits of others that do not hybernate. If we X 2 310 COSMIC PHILOSOPHY. [pi. ii. bringing about precisely the same state of things with which it started. But where there are a vast number of forces at work, as in the evolution of the earth and of life upon its surface, the probability is infinitely small that any pair of forces can so far predominate over all the rest as to reduce their effects to comparative insignificance. Hence the result- ing rhythms will not be closed curves, but endlessly com- plicated undulations ; and every rhythm will end in bringing about a state of things somewhat different from that in which it started. To recur to some of the illustrations above given : — No geologic rhythm of elevation and subsidence leaves the distribution of land and water over the earth exactly as it found it. No biologic rhythm of sleep and wakefulness leaves the distribution of nutritive forces in the organism precisely as it found it; otherwise it would not be true that each day's functional activity is a member of the series of changes which is bearing us from the cradle to the grave. In an exogenous tree each annual rhythm results in a permanent increase of woody fibre : in a mammal it results in at least a relative increase of the solid constituents of the body as compared with the fluid and semi-fluid con- stituents. And our illustration from palaeontology shows that the series of enormous rhythms in which the history of organic life consists, has introduced a new state of things in each geologic epoch.^ We have now proceeded as far as a survey of the widest generalizations of physics can carry us, and before we attempt to go further, we may fitly present in a single view the con- clusions reached in this and in the preceding chapter. We observed first that the three departments of abstract- concrete science are alike concerned with the investigation of the general laws of force as manifested in the motions of ^ Hence the theory of Vioo, that social progress takes place in cycles in which history literally repeats itself, is based upon a very inadequate know- Icilge of the results of the coojieration of many interacting forces. CH. II.] £11 YTHM. 31 1 matter. By an analysis of the widest propositions which these sciences can furnish, concerning the movements of masses and uiolfciiles, we arrived at the axiom that every manifestation of force must be preceded and followed by an equivalent manifestation. We saw that this axiom is involved, alike in every special theorem with which each physical inquiry sets out, and in the general theorem of the uniformity of law and the universality of causation with which all physical inquiries must equally set out. We saw next that this axiom gives rise to three corollaries which, as expressing truths that transcend the sphere of any single science, belong to that transcendental region of knowledge which we have assigned to philosophy. By our first corollary it appeared that any given mode of motion may be metamorphosed into several other modes ; so that, when we contemplate such a complex system of motions as that presented by the various aggregations of matter upon the surface of our earth, it becomes legitimate to inquire from what antecedent form of energy proceeded all these motions. This inquiry we shall make in due season. By our second corollary it appeared that where motion results from the composition of two or more forces, it must always take place in the line of least resistance ; but that the difficulty of calculating or predicting this resultant line must increase very rapidly with each addition to the number of forces which are concerned in producing it. Our third corollary has given us glimpses of a truth, which, though less immediately obvious, is equally necessary and equally important with any of the foregoing. We have seen that, in the hypothetical case of a single moving body in an otherwise empty universe, the direction of motion would be in a straight line, and the velocity would be uniform. In the hypothetical case of a single pair of mutually attracting bodies moving in independent directions in an otherwise empty universe, the motion would be rhythmical both in CHAPTER III. EVOLUTION AND DISSOLUTION. We must now consider what use is to be made of these universal truths which the foregoing survey of the abstract- concrete sciences has disclosed. For if we inquire whether these theorems, singly or combined, can be made to supply the materials needful for constructing such an organized body of truths as may fitly be called Cosmic Philosophy, — it will require but a brief consideration to show us that much more is needed. In respect of universality, no doubt, these truths leave nothing to be desired. That every manifestation of force must be preceded and followed by an equivalent manifesta- tion ; that correlated forms of energy are transmutable one into the other ; that motion follows the line of least resist- ance ; and that there is a continuous rhythmical redistribu- tion of matter and motion ; — these are propositions which are true alike of all orders of phenomena, and may therefore justly claim to be regarded, in a certain sense, as philosophic truths. Yet we need only fancy ourselves enunciating these abstract theorems as of themselves supplying the explanation of any given order of concrete phenomena, in order to realize how far we still remain from our desired goal. If we were to remind a biologist that in every step of his investigations he takes for granted the persistence of force, he would doubt- cii. III.] EFOLUTION AND DISSOLUTION. 315 less assent ; but if we were to go on and assert that upon this axiom might be directly reared a science of organic phenomena, he would laugh us to scorn. If we were to assure him that every form of energy manifested by his organisms, from the molar motions of the stomach in diges- tion and the lungs in respiration to the molecular motions of cerebral ganglia, must have pre-existed in some other form, he would thoroughly agree with us, but would ask us of what use is all this unless we can trace the course and the results of the transformations. If we were still to insist that all the motions taking place in the aforesaid organisms occur rhythmically, along lines of least resistance, and that every such rhythm ends in a more or less considerable redis- tribution of molecular motions, we might still be met by the answer that all this does not give us a science of biology unless we can also point out the general character and direc- tion of the changes in which organic rhythms result. In other words our biologist might say to us, with Mr. Spencer, that all these profound truths, with which we were seeking to take away his occupation, are analytical truths, and that " no number of analytical truths will make up that synthesis of thought which alone can be an interpretation of the synthesis of things. The decomposition of phenomena into their elements," (he would continue,) "is but a preparation for understanding phenomena in their state of composition, as actually manifes+ed. To have ascertained the laws of the factors is not at all to have ascertained the laws of their cooperation. The question is, not how any factor behaves by itself, or under some imagined simple conditions ; nor is it even how one factor behaves under the complicated condi- tions of actual existence. The thing to be expressed is the joint product of the factors under all its various aspects. Only when we can formulate the total process, have we gained that knowledge of it which Philosophy aspires to." ^ ' First Principles, p. 274. 316 COSMIG PHILOSOPHY. [pt. ii. It is necessary for us therefore, having finished our analysis, to begin the work of syntliesis. In the course of our search for the widest generalizations of Physics, we dis- covered, as the most concrete result of analysis, that there is going on throughout the known universe a continuous redis- tribution of matter and motion. Let us now, following out the hint of our imaginary interlocutor, endeavour to ascertain the extent, character, and direction of this continuous redis- tribution. Have the infinitude of changes in the aspect of things, which the rhythm of motion necessitates, any common character, and if they have, what is that character ? Are the redistributions of matter and motion, which are going on all around us, aimless and unrelated, or do they tend in common toward some definable result ? Can any formula be found which will express some dynamic principle, true of the whole endless metamorphosis ? Or, to state the case in a still more concrete form, when we assert " that knowledge is limited to the phenomenal, we have by implication asserted that the sphere of knowledge is coextensive with the phenomenal. Hence, wherever we now find Being so conditioned as to act on our senses, there arise the questions — how came it thus conditioned ? and how will it cease to be thus conditioned ? Unless on the assumption that it acquired a sensible form at the moment of perception, and lost its sensible form the moment after perception, it must have had an antecedent existence under this sensible form, and will have a subsequent existence under this sensible form. These preceding and succeeding existences under sensible forms are possible subjects of knowledge ; and knowledge has obviously not reached its limits until it has imited the past, present, and future histories into a whole."! Let us not faU. to note that science and ordinary know- ledge concern themselves with such problems no less than ' First Prii}ciphs, p. 278. cii. iii.J EVOLUTION AND DISSOLUTION. 317 philosophy; and that in seeking to formulate the past, present, and future history of that aggregate of sensible phenomena which constitutes the knowable universe, philo- sophy transcends the sphere of science in just the same way that science transcends the sphere of ordinary knowledge, and in no other. A large portion of that imperfectly- organized knowledge which serves to guide the actions even of the least educated men, consists of information concerning the past and future careers of the objects which surround them. Thus we recognize the child of twenty years ago in the grown man of to-day ; we know that the coat which the man wears recently existed in the shape of unspun and unwoven wool upon a .sheep's back ; and that the grass upon which this sheep fed, consisted of matter integrated by countless seeds with the aid of solar radiance. And we know, besides, that the man and the coat which he wears, the sheep and the grass upon which it feeds, must alike pass from their present state of aggregation into a future state of dissolution. This kind of knowledge science is ever extend- ing, as when it traces back the man and the sheep to microscopic germ -cells, and the wool and the grass to certain nitrogenous and hydro-carbon compounds, pre-existing in the atmosphere and soil. Obviously, therefore, it is the business of philosophy, extending and generalizing the same kind of information, to describe the universal features of the process by which cognizable objects acquire and lose the sensible forms under which we know them. By pointing out the two most obvious features of this process, we shall render still more intelligible the character of the problem which a synthetic philosophy must attempt to solve. The foregoing illustrations show us that a complete account of anything " must include its appearance out of tlie imperceptible, and its disappearance into the impercep- tible." Now a change of state by virtue of which any object ceases to be imperceptible and becomes perceptible, must be 318 COSMIC PHILOSOPHY. [pt. ii. a change from a state of diffusion to a state of aggregation ; and the converse change, from aggregation to diffusion, must be tlie cliange by virtue of which the object again becomes imperceptible. If, for example, we study a cloud, we find that a complete history of it is contained in the explanation of its concentration from millions of particles of aqueous vapour, and its subsequent dissipation into a host of such par- ticles. In like manner, if we study an organism, we find that from germination to final decomposition, its career consists of an epoch of concentration followed by an epoch of diffusion. A very small portion of its constituent matter pre-existed in a concentrated form in the embryo ; by far the greater portion pre-existed in the shape of dispersed nitrogenous and carbonaceous compounds, which the growing organism has incorporated with its own structure. JSTay, even if we inquire into the previous history of the small portion which was concentrated in the embryo, we may trace it back to an epoch at which it existed in a state of dispersion, as food not yet assimilated by the parent organism. If the organism in question belong to an order of carnivorous animals, we shall indeed have to follow its constituent ele- ments through a series of phases of concentration ; through the tissues of sundry herbivorous animals upon which it has fed, and again through the tissues of numerous plants upon which these have in turn subsisted ; but in the end we shall always arrive at the host of dispersed molecules which these organisms have eliminated from the breezes and the trickling streamlets by which their leaves and roots were formerly bathed. On the other hand, when the animal dies, and the tree falls to decay, the particles of which they consist are again dispersed ; and though they may again be brought together in new combinations, the career of the organism in question is ended with this dispersal. Again if, instead of a transient cloud or a mobUe organism, we contemplate an apparently permanent and immobile rock, we are led tQ a CH. ni.J EVOLUTION AND DISSOLUTION. 319 like conclusion. If its origin he purely igneous, this rock may have pre-existed as a liquid stream of matter surging heneath the earth's solid envelope. If its origin be aqueous, its con- stituent particles were once diffused over a wide area of country, from which they were drawn together through sundry rivulets and rivers, and here at last deposited as sediment. In either case the process by which the rock has assumed an individual existence has been a process of concentration. And when it ceases to exist— whether it is blasted with gunpowder, or chipped away with chisels, or eaten down by running water, or ground to pieces by ocean waves, or lowered through some long geologic epoch until it is melted by volcanic heat — in any case its disappearance is effected by a process of diffusion. But our account is as yet only half complete. In saying that the career of any object, from its initial appearance to its final disappearance, consists of a process of concentra- tion followed by a process of diffusion, we omit an important half of the truth. For in making such a statement, we are attending only to the material elements of which objects are composed; and we are leaving out of the account the motions, both molar and molecular, which they exhibit, and which constitute an equally important part of the entire process. This defect we must now endeavour to remedy. A brief reconsideration of the examples already cited will show us that universally the concentration of matter is ac- companied by a dissipation of motion, while conversely the diffusion of matter is attended by an absorption of motion. The condensation of aqueous vapour into a cloud is effected whenever it loses by radiation a greater quantity of that kind of molecular motion known as heat than it is receiving from the sun and the earth ; ■ and when the loss of motion is still more considerable, there occurs a further condensation of the aqueous vapour into liquid rain. Conversely, when solar radiance, direct or reflected, begins to impart to the 320 COSMIC PHILOSOPHY. [pt. ii. condensing cloud an amount of molecular motion in excess of that wMch it loses from moment to moment, condensation ceases, and the particles of vapour begin to be dissipated. The deposit of sediment at the mouth of a river is attended by the loss of the molar motions which brought its con- stituent particles from the upland regions which the river drains ; and the hardening of the sediment into rock is a change to a state of aggregation in which, along with greater cohesion, the particles possess less mobility than before. In like manner the hardening of an igneous rock is effected by cooling, which implies the loss of internal motion. In- deed the phenomena of heat and cold exhibit en masse an illustration of the general principle. The progress of any mass of matter from a gaseous to a liquid, and thence to a solid state, is attended by the continuous dissipation of molecular motion ; while change in the contrary direction is attended by a continuous absorption of such motion. With molar motions the case is precisely similar. " Augment the velocities of the planets, and their orbits will enlarge ; the solar system will occupy a wider space. Diminish their velocities, and their orbits will lessen ; the solar system will contract. And in like manner we see that every sensible motion on the earth's surface involves a partial disintegration of the moving body from the earth, while the loss of its motion is accompanied by the body's reintegration with the earth." Finally, if we consider the case of organisms, we find that the incorporation of food into the substance of the tissues is constantly accompanied by the giving out of motion in some form of organic activity, while conversely, the decomposition which follows death is attended by an immense absorption of molecular motion. The latter state- ment is proved by the fact that the elements of which such an organism as the human body is composed, have more than twenty times the volume when free which they have wlien combined ; and it is further illustrated by the fact en. iii.J EVOLUTION AND DISSOLUTION. 321 that dead organisms, from which all supply of molecular motion from without is artificially cut off, are not decom- posed. It is thus that animal remains are preserved for ages in blown sand and in peat-moss. And it is thus that the carcases of primeval mammoths, intact even to the bulbs of the eyes, are found imbedded in arctic ice near the mouths of Siberia.n rivers, just where they were slain by, the cold a thousand centuries ago.'' But the study of organic phenomena shows us that our general theorem needs some further revision. As it now stands, it runs some rislf of being supposed to assert that the career of any composite body is at first characterized solely by the concentration of matter and concomitant dissipation of motion, and is at last characterized solely by the diffusion of matter and concomitant absorption of motion. A reference to the history of any organism will at once show that this is not the case. While the human body, for example, is con- tinually ■ incorporating with its tissues new matter in the shape of prepared food, large portions of the matter once in- corporated are continually diffused in the shape of excretions through the lungs, liver, skin, and kidneys. And while it is constantly parting with motion, in the shape of radiated heat, of expended nerve-force, and of molar motion com- municated to the surrounding objects which it touches or handles, it is at the same time absorbing large quantities of molecular motion latent in its prepared nutriment. But at no time are the antagonist processes exactly balanced. During early life the excess of concentration over diffusion of matter results in growth. At a later date the rhythms due to the alternate predominance of concentration and diffusion, are ex- hibited in continiial fluctuations in weight. Yet the fact that the healthy body usually increases in weight up to a late period, shows that ordinarily concentration is stiU predo- ' The heads of these animals are nearly always directed southward. See jjyell. Principles of Gcolo-pj, 10th edit. vol. i. p. 184. VOL. I. Y 322 COSMIC PHILOSOPHY. [pt. ii. minant. And this is still more convincingly proved by the fact that in old age, when the body frec[uently decreases both in weight and in volume, the weight decreases less than the volume. There is a general increase in density, and con- comitant loss of mobility, due to the increased ratio of the solid to the fluid constituents of the tissues, and exhibited in the hardness and brittleness of the bones, the stiffness of the joints, the sluggishness of the circulation, and the torpidity of the brain. Finally when, in accordance with the general principle of rhythm, the consolidation has gone so far as to become self-defeating, the antagonist process gains the mastery for which it has all along been striving, and the constituents of the body are separated and scattered. But the coexistence and alternate mastery of these two opposing processes, though most strikingly exemplified in the case of organisms, is by no means confined to organic pheno- mena. Neither in the cloud, nor in the rock, which we have chosen as examples, does concentration or diffusion ever go on alone. The one is always antagonized by the other. Even while the' cloud is most rapidly losing motion and inte- grating matter, it is receiving some solar radiance, either direct or reflected from the earth or moon, and the absorption of this radiance causes some disintegration of its matter. Even while it is most quickly vanishing under the burning solar rays, this cloud is still simultaneously losing heat by radiation, and the loss tends to reintegrate it. And likewise our sedimentary rocky deposit, while aggregating, is never- theless daily abraded by passing currents, and at longer intervals is perhaps cracked by those telluric vibrations known as earthquakes. As finally amended then, our formula asserts that the career of any composite body is a series of more or less complicated rhythms, of which the differential result is, at first, the integration of its constituent matter and the dissipa- tion of part of its contained motion, and, at last, the diffusion CH. III.] EVOLUTION AND DISSOLUTION. 323 of its constituent matter accompanied by reabsorption of the lost motion, or its equivalent. Thus we are gradually reaching something like a concrete result. As we saw, in the preceding chapter, that rhythm necessitates a continual redistribution of matter and motion throughout the knowable universe, we now find that this continual redistribution everywhere results in alternate con- centration and diffusion. Such, indeed, must inevitably be the result. The same universal principle of dynamics which prevents the perturbations in the solar system from ever accumulating all in the same direction, is also to be seen exemplified, on a more general scale, in the law that neither aggregation nor diffusion can proceed indefinitely without being checked by the counter-process. Unless we suppose that the sum of the forces which produce aggregation is infi- nitely greater or infinitely less than the sum of the forces which resist aggregation, so that either the one or the other may be left out of the account, we must admit that the only possible outcome of the conflict between the two is a series of alternations, both general and local, between aggregation and dissipation. It is now the time to apply to these antagonist processes some more convenient and accurate names than the half- dozen pairs of correlative synonyms by which we have thus far described them. The names selected by Mr. Spencer will be practically justified by the entire exposition contained in the following chapters ; but even the cases already frag- mentarily studied enable us partly to realize the significance of the terms Evolution and Dissolution, by which he has designated these processes. In Mr. Spencer's terminology, the integration of matter and concomitant dissipation of motion is Evolution; while the absorption of motion and concomitant disintegration of matter is Dissolution. Both these terms possess the signal advantage that, while they admit of precise scientific definition, they are at the same Y 2 324 COSMIC PHILOSOPHY. [pt. ii. time currently used in senses strictly analogous to those in which they are here employed. As we shall presently see, the phenomena of organic life are those in which both the primary and the secondary characteristics of Evolution and Dissolution are most conspicuoiisly exemplified. Especially in the career of the animal organism, these complementary processes are manifested in groups of phenomena that are more easily generalized and more immediately interesting than any others of like complexity ; and to these groups of phenomena the terms Evolution and Dissolution have long been popularly applied. On a superficial view it may now seem as if we were ready to proceed, in the next chapter, to describe in detail the process of Evolution, as exemplified in that most gigantic instance of concentration of matter and dissipation of motion, — the development of our planetary system, by condensation and radiation, from ancestral nebulous matter. In this origin, by aggregation, of our system of worlds, and in that ultimate dissipation of it into nebulous matter which sundry astronomic facts have long taught us to anticipate, we shall presently find a complete and striking illustration of the dynamic principles herein set forth. But we are not yet quite prepared to enter upon the consideration of these phenomena. We need but remember that in the develop- ment of the solar system, with its mutually dependent members sustaining complex and definite relations to each other, much more is implied besides concentration of plane- tary matter and diffusion of molecular motion in the shape of heat; we need but remember this, and we shall see that some further preliminary study is requisite. While, indeed, the primary characteristics of Evolution and Dissolution are those which are expressed in the pair of definitions above given, and which it has been the object of the foregoing inquiry to illustrate ; there are also, as just hinted, certain secondary characteristics which it is equally necessary to CH. III.] EVOLUTION AND DISSOLUTION. 325 formulate. While Evolution always consists primarily in an integration of matter and concomitant dissipation of motion, it ordinarily implies mucli more than this. And it is obvious that only when all the characteristics, both primary and secondary, of Evolution and Dissolution, are expressed in a single formula, can we be said to have obtaiaed the law of the continuous redistribution of matter and motion which rhythm necessitates throughout the knowable universe. To show how this — the most sublime achievement of modern science — has been brought about, will be the object of the following chapter. CHAPTER IV. THE LAW OF EVOLUTION. Laplace has somewhere reminded us that, while gratefully rendering to Newton the homage due to him for his trans- cendent achievements, we must not forget how singularly fortunate he was in this — that there was but one law of gravitation to be discovered. The implication that, if ISTewton had not lived, Laplace might himself have been the happy discoverer, is perhaps a legitimate one, though it does not now especially concern us. But the implied assertion that Nature had no more hidden treasures comparable in worth and beauty to that with which she rewarded the patient sagacity of the great astronomer, is one which recent events have most signally refuted. We now know that other laws remained behind — as yet others still remain — unrevealed ; laws of nature equalling the law of gravitation in universality, and moreover quite as coy of detection. For while it may be admitted that the demonstrations in the "Principia" required the highest power of quantitative reasoning yet manifested by the human mind; and while the difficulties and discouragements amid which Newton approached his task, destitute as he was alike of modern methods of mea- surement and of the resources of modern analysis, impress upon us still more forcibly the wonderful character of the CH. IV.] THE LAW OF EVOLUTION. 327 achievement; it must still be claimed that the suucessful coordination of the myriad-fold phenomena formulated by the Law of Evolution, was a gigantic task, requiring the full exertion of mental powers no less extraordinary than those required by the other. In an essay published thirteen years ago, youthful enthusiasm led me to speak of Mr. Spencer's labours as comparable to those of Newton both in scope and in importance. More mature reflection has confirmed this view, and suggests a further comparison between the mental qualities of the two thinkers ; resembling each other as they do, alike in the audacity of speculation which propounds far- reaching hypotheses and in the scientific soberness which patiently verifies them ; while the astonishing mathematical genius peculiar to the one is paralleled by the equally unique power of psychologic analysis displayed by the other. As in grandeur of conception and relative thoroughness of elabo- ration, so also in the vastness of its consequences — in the extent of the revolution which it is destined to effect in men's modes of thinking, and in their views of the universe — Mr. Spencer's discovery is on a par with Newton's. In- deed, by the time this treatise is concluded, we may perhaps see reasons for regarding it as, in the latter respect, the superior of the two. To give anything like an adequate idea of the extent and importance of this discovery, or of the enormous mass of inductive evidence which joins with deduction in establish- ing it, is of course impracticable within the limits of a single chapter. We must be content for the present with ex- hibiting a rude outline-sketch of its most conspicuous features, leaving it for the succeeding series of discussions to finish the picture. Let us begin by briefly summing up the results already obtained. It has been shown that the coexistence of antagonist forces throughout the knowable universe necessitates a uni- versal rhythm of motion; and that in proportion to the 328 COSMIC PHILOSOPHY. [pt. ii. number of forces anywhere concerned in producing a given set of motions, the resulting rhythms are complex. It has been further shown that, save "where the rhythms are abso- lutely simple — a case which is never actually realized — there must occur a redistribution of matter and motion as the result of each rhythm. It next appeared that such a redistribution involves on the one hand an integration of matter, which implies a concomitant dissipation of motion, and on the other hand a disintegration of matter, which implies a concomitant absorption of motion. The former process, which results in the acquirement of an individual existence by sensible objects, has been named Evolution : the latter process, which results in the loss of individual existence by sensible objects, has been named Dissolution. And we saw it to be a corollary from the universality of rhythm that, while these two antagonist processes must ever be going on simultaneously, there must be an alternation of epochs during which now the former and now the latter is predominant. In conclusion, it was barely hinted that these two fundamental modes of redistribution must give rise, in the majority of cases, to secondary redistributions, which it is the business of a scientific philosophy to define and formulate. ^ovf, as we are about to start upon a long and complicated inquiry, the proper treatment of which must task our utmost resources of exposition, it will be desirable at the outset to disencumber ourselves of all such luggage as we are not absolutely obliged to take along with us. We shall there- fore, for the present, leave the process of Dissolution entirely out of the account, or shall refer to it only incidentally, in cases where such a reference may assist in the elucidation of the counter-process. In the following chapter we shall have occasion to treat of Dissolution in some detail as exemplified in the probable future disintegration of our planetary system ; at present we are concerned only with Evolution, which we cii. IV.] THE LAW OP EVOLUTION. 329 have already seen to consist in the integration of matter and concomitant dissipation of motion, but which, as we shall presently see, implies in most cases much more than this. Let us first point out the conditions under which the secon- dary redistributions attending Evolution take place ; and let us then proceed to point out the common characteristics of these secondary changes. Obviously in speaking of secondary redistributions that go on while a body is integrating its matter and losing its motion, we refer to redistiibutions among the parts of the body a.nd among the relative motions of the parts, — or, in other words, to alterations in structure and function going on within the body. Now the ease with which such redistribu- tions are effected, and the ease with which they are maintained, must depend alike, though in precisely opposite vs'ays, upon the amount of motion retained by the integrating body. The greater the amount of retained motion, the more easily will internal redistributions be effected. The smaller the amount of retained motion, the more easily will such redistributions be rendered permanent. These propositions aie so abstruse as to require some further illustration. When water is converted, by loss of its internal motion, into ice, the amount of secondary rearrangement which occurs among its particles is comparatively slight, but it is permanent so long as the state of integration lasts. During the continuance of the solid state there is not enough mobility among the particles to admit of further rearrange- ment to any conspicuous extent. On the other hand, after steam has been integrated into water, the retention of a con- siderable amount of molecular motion allows internal re- arrangement to go on so easily and rapidly that no momentary phase of it has a chance to become permanent; and there can thus be no such stable arrangement of parts as we call structure. The phenomena of crystallization supply us with kindred, but slightly different examples. When a crystal is 330 008MT0 PHILOSOPHY. [pt. ii. deposited from a solution, there is a certain point up to which the retention of motion keeps the crystal's molecules from uniting ; but as soon as this point is passed, the motion is suddenly lost, the crystal solidifies, and there is no further redistribution of its particles. Conversely, when a molten metal is allowed to cool until it assumes a plastic semi-fluid state, its molecular motion is lost so slowly that a perceptible rearrangement of parts is possible : currents may be set up in it, gravity will cause it to spread out wherever it is not confined at the side, and pressure here and there will variously mould it. But when it becomes solid, the rearrangements which occurred latest become permanent, and further re- arrangements cannot be produced save by a fresh supply of molecular motion. In like manner, when we come to study planetary evolution, we shall find strong reasons for believing that on small bodies, like the moon and the asteroids, which have rapidly lost their internal heat, there has been but little chance for such complex secondary rearrangements as have occurred upon our relatively large and slowly cooling earth. Even after the attainment of solidity, however, a new supply of motion from without may cause some further redistribution without causing the body to relapse into fluidity. Thus a wrought-iron rail, which when new is tough and fibrous, gradually acquires the brittle crystalline texture of cast-iron, under the influence of the vibrations communicated by the cars which pass over it. And the magnetization of steel rods, when fastened in the meridian and frequently jarred, is cited by Mr. Spencer as a fact of like import. Many other excellent illustrations, gathered from physics and chemistry, may be found in the thirteenth chapter of the second part of " First Principles."^ ' Throughout this work, reference is made only to the second and re- written edition of " First Principles," London, 1867. The statement of the law of evolution, as contained m the first edition, is much less complete and coherent. CH. IV.] THE LAW OF EVOLUTIOy. 331 If now we contemplate in a single view the general principles above illustrated, we shall seem for a moment to have got into difficulties. Unavoidably, in using the word Evolution, we have suggested the idea of increase in structural complexity ; and such increase of course implies a con- siderable amount of permanent internal rearrangement as consequent upon the primary process of integration. Yet under the conditions thus far studied, we find that " on the one hand, a large amount of secondary redistribution is possible only where there is a great quantity of contained motion ; and, on the other hand, these redistributions can have permanence only where the contained motion has become small — opposing conditions which seem to negative any large amount of permanent secondary redistribution." We must therefore search for some more peculiar and special combination of conditions before we can understand how Evolution may result in great structural complexity. It is in the case of organic bodies " that these apparently contradictory conditions are reconciled ; and that, by the reconciliation of them, permanent secondary redistributions immense in extent are made possible." The distinctive peculiarity of organic bodies " consists in the combination of matter into a form embodying an enormous amount of motion at the same time that it has a great degree of concentration." Let us enumerate the several ways in which organic bodies are enabled to retain vast quantities of molecular motion, without losing their high degree of concentration. The facts to be contemplated are among the most beautiful and striking facts which the patient interrogation of nature has ever elicited. In the first place, while one of the four chief components of organic matter is carbon, a solid substance which cannot be fused by the greatest heat that man can produce, the other chief components — oxygen, hydrogen, and nitrogen — are gases which human art is unable to liquefy. At a temperature 334 COSMIC PHILOSOPHY. [pt. ii. the most important of the chemical elements concerned in maintaining vital activity. Now when we compare this property of nijirogen with the apparent excess of carbon in the albumen-molecule, we may fairly surmise that the two facts indicate a balance between the forces that tend to pro- duce internal rearrangement and the forces that tend to prevent disintegration. Fifthly, besides the fact that organic bodies usually possess an amount of heat which keeps their temperature somewhat above that of their inorganic environment, we have to note the fact that all organic matter is permeated by water. Hence, while sufficiently solid to preserve their continuity of structure, organic bodies are sufficiently plastic to allow of much internal rearrangement. If we had time, it would be interesting to go on and trace the facts just enumerated through many complex exemplifi- cations. We might comment at length upon the significance of the facts that certain animals, as the Roiifera, lose their vitality when dried and regain it when wetted ; that vital activity everywhere demands a supply of heat, and that the most complex organisms are in general the warmest ; that animals contain more nitrogen than plants, and are at the same time more highly evolved; that carnivorous animals are relatively stronger and more active than herbivorous animals ; that the parts of animals which are the seats of the highest vitality are mainly nitrogenous, while the more inert parts are mainly carbonaceous ; that the highly nitro- genous matter composing the nervous system is nevertheless —as if to preserve the balance — always accompanied by inert carbonaceous fat; and that, while a nitrogenous diet renders possible the greatest quantity of physical and mental activity, at the same time carbonaceous alcohol retards the waste of nervous tissue. But even without entering upon such a course of illustra- tion — which would oblige us to defer our main subject untU CH. IV.] THE LAW OF EVOLUTION. 335 another occasion — we are now enabled to see Low it is that organic bodies can practically solve the dynamic paradox of acquiring a high degree of concentration, even while retain- ing an immense amount of motion. We are prepared to find, under these quite peculiar conditions, the structural rearrangements characteristic of Evolution carried on to a great extent. And we need not be surprised at finding these secondary phenomena here displayed so conspicuously as to obscure the significance of the primary phenomenon, inte- gration. It was, in fact, through the study of organic pheno- mena by physiologists that a formula was first obtained for the most conspicuous features of Evolution ; while the less obtrusive but more essential feature not only remained un- noticed until Mr. Spencer discerned it, but was not ade- quately treated even by him previous to the publication of his rewritten " First Principles," in 1867. I think it there- fore advisable, in dealing with the law as generalized from organic phenomena, to begin by describing these most con- spicuous features. We shall thus obtain a clearer view of the whole subject than we could well obtain in any other way. Having shown that Evolution is always and primarily an integration of matter attended by a dissipation of motion ; and having shown that under certain conditions, most com- pletely realized by organic bodies, certain secondary but equally important phenomena of structural rearrangement may be expected to accompany this fundamental process ; we must next show what these secondary phenomena are. The exposition will be rendered clearer by the preliminary explanation of four technical terms, which wlH continually recur, and which must be thoroughly understood before any further step can be taken toward comprehending the Law of Evolution. These terms are neither obscure in themselves, nor newly coined, but because we shall henceforth employ them in a strict and special sense, they require careful definition. 33(5 COSMIC PHILOSOPHY. [tt. u. I. An object is said to be homogeneous when each of its parts is like every other part. An illustration is not easy to find, since perfect homogeneity is not known to exist. But there is such a thing as relative homogeneity ; and we say that a piece of gold is homogeneous as compared with a piece of wood; or that a wooden ball is homogeneous as compared with an orange. II. An object is said to be heterogeneous when its parts do not all resemble one another. All known objects are more or less heterogeneous. But, relatively speaking, a tree is said to be heterogeneous as compared with the seed from which it has sprung ; and an orange is heterogeneous as compared with a wooden ball. III. Differentiation is the arising of an unlikeness between any two of the units which go to make up an aggregate. It is the process through which objects increase in heteroge- neity. A piece of cast-iron, before it is exposed to the air is relatively homogeneous. But when, by exposure to the air, it has acquired a coating of ferric oxide, or iron-rust, it is relatively heterogeneous. The units composing its outside are unlike the units composing its inside ; or, in other words, its outside is differentiated from its inside. IV. The term integration we have already partly defined as the concentration of the material units which go to make up any aggregate. But a complete definition must recognize the fact that, along with the integration of wholes, there goes on (in all cases in which structural complexity is attained) an integration of parts. This secondary integra- tion may be defined as the segregation, or grouping together, of those units of a heterogeneous aggregate which resemble one another. A good example is afforded by crystallization. The particles of the crystallizing substance, which resemble each other, and which do not resemble the particles of the solvent fluid, gradually unite to form the crystal ; which is thus said to be integrated from the solution. Integration is -en. IV.] Til K- LAW OF EVOLUTION. 337 also seen in the rising of cream upon the surface of a dish of milk, and in the frothy collection of carbonic-acid bubbles covering a newly-filled glass of ale. Obviou.sly as it is through differentiation that an aggregate increases in heterogeneity, so it is through integration that an aggregate increases in definiteness, of structure and function. But there is still another way in which integration is exem- plified. Along with increasing heterogeneity and definiteness of structure and function, the evolution of an aggregate is marked by the increasing subordination of the various func- tions, with their structures, to the requirements of the general functional activity of the aggregate. In other words, along with growing specialization of parts, there is a growing cooperation of parts, and an ever -increasing mutual de- pendence among parts. An illustration is furnished by the contrasted facts, that a slightly-evolved ■ animal, like a common earth-worm, may be cut in two without destroy- ing the life of either part ; while a highly-evolved animal, like a dog, is destroyed if a single artery is severed, or if any one of the viscera is prevented from discharging its peculiar functions. This third kind of integration is the process through which an evolving aggregate increases in coherence. And with this, our definition of the factors which concur in the process of evolution is complete. We are now prepared to show inductively that wherever, as in organic aggregates, the conditions permit, the integration of matter and concomitant dissipation of motion, ivhich •primarily constitutes Evolution, is attended hy a contimious change from indefinite, incoherent homogeneity to definite, coherent heterogeneity of structure and function, through successive differentiations and integrations. In illustration of this statement, let us describe first, some of the differentia- tions, and secondly, some of the integrations, which suc- cessively occur during the development of an individual organism. VOL. I. z 338 COSMIC PHILOSOPHY. [ft. n. Two centuries ago the researches of Harvey on generation established the truth that every animal at the outset consists simply of a structureless and homogeneous germ. Whether this germ is detached from the parent organism at each generation, as in all the higher animals, or only at intervals of several generations, as for example, in the ApUcles or plant-lice, matters not to the general argument. In every case the primitive state of an animal is a state of relative homogeneity. The fertilized ovum of a lion, for instance, possesses at first no obvious characteristic whereby it can be distinguished from the fertilized ovum of a man, a dog, a parrot, or a tortoise. Each part of the germ-cell is, moreover, as nearly as possible like every other part, in molecular texture, in atomic composition, in temperature, and in specific gravity. Here in two ways we may notice how homogeneity is eventually succeeded by heterogeneity. In the first place, all animal germs are homogeneous with respect to each other, while the animals developed from them present all kinds and degrees of diversity ; and, in the second place, each germ is homogeneous with regard to itself, while the creature developed from it is extremely heterogeneous. The vegetable world exhibits a state of things essentially the same, though less conspicuous in its contrasts. Starting from the homogeneous germ, we may follow out a parallel series of differentiations, resulting respectively in molecular rearrangements of chemical elements and in molecular and molar modifications of tissues and organs. The chemical differentiations have been so well and so con- cisely described by Mr. Spencer that I cannot do better than cite the passage entire : — " In plants the albuminous and amylaceous matters which form the substance of the embryo, give origin here to a preponderance of chlorophyll and there to a preponderance of cellulose. Over the parts that are becoming leaf-surfaces, certain of the materials are meta- morphosed into wax. In this place starch passes into one of CH. IV.] THE LAW OF EVOLUTION. 339 its isomeric equivalents, sugar; and in that place into another of its isomeric equivalents, gum. By secondary- change some of the cellulose is modified into wood ; while some of it is modified into the allied substance which, in large masses, we distinguish as cork. And the more numer- ous compounds thus gradually arising, initiate further un- likenesses by mingling in unlike ratios. An animal ovum, the components of which are at first evenly diffused among one another, chemically transforms itself in like manner. Its protein, its fats, its salts, become dissimilarly proportioned in different localities ; and multiplication of isomeric forms leads to further mixtures and combinations that constitute many minor distinctions of parts. Here a mass darkening by accumulation of haematine, presently dissolves into blood. There fatty and albuminous matters uniting, compose nerve-tissue. At this spot the nitrogenous substance takes on the character of cartilage ; and at that, calcareous salts, gathering together in the cartdage, lay the foundation of bone. All these chemical differentiations slowly and in- sensibly become more marked and more multiplied."^ The differentiations of tissues and organs are equally interesting. In the growth of any exogenous stem, the outer layer, or bark, first becomes distinguished from the woody interior. Then while the bark gradually becomes differentiated into the liber, made up of woody tissue, the green and corky envelopes, made up of parenchyma, and the epidermis ; the interior becomes differentiated into the pith, the medullary sheath, the woody layer, made up of bundles of greatly elongated cells, and the medullary rays, or what is called the silver grain in maple and oak. Meanwhile between this heterogeneous bark and the heterogeneous wood which it surrounds, there appears a zone of delicate cells, charged with dextrine and other assimilable matter, and known as the cambium layer. At the same time 1 First Priiwiples, p. 33 J. z 2 340 COSMIC FHILOSOFHY. [pt- 'i- differentiations are going on at the upper extremity of this complicated structure. Portions of the green envelope protrude from between, the liber and the epidermis, accom- panied by tough fibres sent forth partly by the liber and partly by the woody layer. While the green portions flatten out horizontally, the fibres ramify through them and serve to stiffen them; and thus is developed the leaf, which, when mature, usually exhibits a further differentiation between blade and petiole, while by a continuance of the same process stipules often appear at the base of tlie petiole. Nor is this the end of the story. For wliile the chlorophyll-cells that make up the upper stratum of the leaf-tissue remain densely crowded, and are often covered by a wax-like cuticle, making the upper surface smooth and glossy ; the cells composing the lower stratum become less and less crowded, until the result is a spongy surface, filled with innumerable pores, through which the moisture of the plant may be exhaled. Finally a differentiation arises between the axillary buds, some of which elongate into branches, repeating the chief characteristics of the stem, while others are developed under the still more heterogeneous forms of flowers, with their variously-cleft calyx and corolla, and their variously-com- pounded stamens and pistils. In the fertilized mammalian ovum the earliest step toward heterogeneity consists in the division and redivision of the nucleated embryonic cell. As the cell-nucleus grows, by continuous integration of the nutritious protoplasm in which it is imbedded, it slowly becomes grooved, and ultimately divides into a pair of nuclei, about each of which is formed a cell-wall. This process continues until the entire yolk is absorbed, by which time it has become differentiated into a mulberry-like mass of cells. And these cells, at first all alike spherical or nearly so, become club-shaped or hexagonal or pointed, as the mass further consolidates and squeezes them together. A grand differentiation next occurs between CH. IV.] THE LAW OF EVOLUTION. 341 the outer and imier portions of the yolk-mass : the outer cells become flattened and pressed together, so as somewhat to resemble a mosaic pavement, and thus form a peripheral membrane. As this membrane continues to thicken by the integration of adjacent materials, it differentiates into two layers, wrapped the one within the other, like two coats of an onion. The outer layer, or ectoderm, absorbing larger quantities of nitrogenous matter than the other, is the one which by further immense differentiation is destined to produce the bony, muscular, and nervous systems ; while the inner layer, or endoderm, is destined to produce the digestive apparatus. Between these two, by a further differentiation, arises a vascular layer, the rudiment of the circulatory system. Now on the interior surface of the endoderm appears a grooved channel, of which the edges gradually rise and fold over towards each other until joining they form a tube, — the primitive alimentary canal. At first nearly uniform, this channel becomes slowly more and more multiform. ISTear the upper end it bulges so as to form a stomach, while the long lower portion, variously ■^Tapped and convoluted, is differentiated into the small and large intestines. From various parts of the now heterogeneous canal, there bud forth variously-organized secreting glands, — those which make saliva, and those which make gastric juice, bile-cells, pancreatic cells, and intestinal follicles. Wliile from the exterior coat of the endoderm, thus wonderfidly transformed, there shoot out, near the upper end, little flower-like buds, which by and by become lungs. In the intermediate or vascular layer, equally notable differentiations simultaneously occur. The vascular channels become distinguished as veins, arteries, and capillaries. " The heart begins as a mere aggregation of cells, of which the inner liquefy to form blood, while the outer are transformed into the walls." Presently the auricle, or chamber which receives blood, is differentiated from the ventricle, or chamber which expels it ; and still later 342 COSMIC PHILOSOPHY. [pt. ii. a partition-wall divides first the ventricle and afterwards the auricle into two portions— one for the venous, the other for the arterial blood. Along with all these changes, parallel processes, too mimerous to be more than hinted at, are going on in the ectoderm. Masses of nitrogenous cells here give rise to muscles, which ramify through the whole interior of the embryo ; and there to cartilaginous structures, in which deposits of earthy phosphate, hardening around certain centres, generate bone. The nervous system, first appearing as a mere groove upon the surface of the germinal membrane, finally exhibits an almost endless heterogeneity. First there is the difference between grey and white tissue, of which the first generates the peculiar kind of molecular motion vaguely termed nerve-force, while the latter transmits such motion. Then there are the differences between the nervous centres which, differently bundled together, make ixp the cerebrum, the cerebellum, the corpora quadrigemina, the medulla oblongata, the spinal cord, and the sympathetic ganglia, each of which aggregates is extremely heterogeneous in itself And then there are the innumerable differences entailed by the highly complicated connections established between one nervous centre and another, by the inosculations of different sets of nerves with each other, and by the circum- stance that some nerves are distributed upon muscles, others upon glands, and others upon ganglia. These must suffice as examples of differentiation. To go on until we had exhausted the series of differentiations which attend the evolution of a single individual, would be to write the entire history of an organism, and thus to convert our philosophic discussion into a special scientific monograph. That history was long since thoroughly written by Von Baer. Following out hints furnished by Liuneeus, K. F. Wolff, Goethe, and Schelling, this illustrious embryologist announced, in 1829, his great discovery that the progressive change from homogeneity to heterogeneity is the change in which cu. IV.] THE LAW OF EVOLUTION. 343 organic evolution essentiaUy consists. It was this formula which Mr. Spencer began, some twenty years later, to ex- tend into the universal law of evolution. But, far from having anticipated the essential portion of Mr. Spencer's discovery. Von Baer's formula stands in much the same relation to it in which the speculations of Copernicus stood with reference to the discovery of Newton. Just as Copernicus was essen- tially in error in maintaining that the planets revolve in circular orbits, Von Baer was essentially in error in considering the process of differentiation as the fundamental charac- teristic of evolution, as well as in ignoring the process of integration. The whole foregoing exposition has shown, and the entire remainder of the exposition will still further con- vince us, that the fundamental characteristic of evolution is integi'ation of matter with dissipation of internal motion ; and that the change from homogeneity to heterogeneity is but the secondary rearrangement which results wherever the retained motion is great enough to allow it. Still more, in ignoring the process of integration, Von Baer failed to include in his formula that change from indefiniteness and incoherence to definiteness and coherence, which is equally important with the change from homogeneity to heterogeneity. In the evolution of an organic germ, integration is just as essen- tial a part of the whole process as differentiation. If the latter were alone to take place, the result would simply be a chaotic medley of organs and tissues. Both operations are requisite to produce a system of organs capable of working in concert. And if differentiation goes on, unattended by integration, in any part of the body, disease, and often death, is the result. Cancers and malignant tumours are merely indefinite results of differentiation, which, never becoming integrated into harmony with the rest of the organism, end by maiming and finally destroying it. As Dr. Beale has shown, a cancer is a new variety of cellular tissue, fungoid in character, which grows at the expense of the organism, and 344 COSMIC PHILOSOPHY. [ft. ii. eats it up as effectually as a carnivorous enemy could eat it. To employ an instructive metaphor, a cancer is a rebellion within the organism, — a setting up of an indepen- dent centre of government, — a fatal interference with the sabordination of the parts to the whole. Yet the organism in which a cancer has begun to grow is more heterogeneous than the healthy organism. In like manner the first stages of decomposition increase the heterogeneity of the organism as a whole ; but because each new retrograde product follows henceforth a career of its own, free from the control of the organic aggregate, the result is not evolution, but dissolution. The differentiations which occur duiing the normal growth of the germ, differ from those which constitute cancer and gangrene, alike in their common subordination to the pri- mary process of growth, and in the definiteness of the resulting structures. " In the mammalian embryo, the heart, at first a long pulsating blood-vessel, by and by twists upon itself and integrates. The bile-cells constituting the rudi- mentary liver, do not simply become different from the wall of the intestine in which they at first lie ; but as they accumulate, they simultaneously diverge from it, and con- solidate into an organ. The anterior segments of the cerebro- spinal axis, which are at first continuous with the rest, and distinguished only by tlieir larger size, undergo a gradual union ; and at the same time the resulting head folds into a mass clearly marked off from the rest of the vertebral column. The like process, variously exemplified in other organs, is meanwhile exhibited by the body as a whole; which be- comes integrated somewhat in the same way that an outspread handkerchief and its contents become integrated when its edges are drawn in and fastened to make a bundle." Mr. Spencer, from whom I have quoted this embryologic illus- tration, goes on to cite parallel instances in the development of lower forms of animal life ; a few of which may be here epitomized. In the growth of the lobster from its embryo, a cii. IV.] THE LAW OF EVOLUTION. 345 number of calcareous segments, originally separable, become integrated into the compact boxes wbicli envelope the organs of the head and thorax. A similar concentration occurs in the spider, the bee, and the butterfly. In contrast with this, we may profitably observe what goes on in many annuloid worms, where the multiplication of segments by differen- tiation results in the fission of the animal into two distinct individuals, because the integrating power of the organism is slight.^ Similarly in the development of the higher crusta- ^ Here, without prejndice to the general argument, I may call attention to the very ingenious hypothesis propounded by Mr. Spencer, to accoxmt for the origin of the annulose or articulated sub-kingdom of animals. According to this hypothesis, any annulose animal is in reality a compound organi.sm, each of its segments representing what was originally a distinct individual. In other words, an annulose animal is a colony or community of animals which have become integrated into an individual animal. Strong-yrimtJ facie evidence of such a linear joining of individuals primevally separate is furnished by the structure of the lowest annelids. Between the successive segments there is almost complete identity, both internal and external. Each segment is physiologically an entire creature, possessing all the organs necessary for individual completeness of life ; not only legs and hronchiffi of its own, but also its own nerve-centres, its own reproductive organs, and frequently its own pair of eyes. In many of the intestinal worms each segment has an entire reproductive apparatus, and being hermaphrodite, constitutes a com- plete animal. Moreover in the development of the embryo the segments grow from one another by fission or gemmation, precisely as colonies of com- pound animals grow. At the outset the embryo annelid is composed of only one segment. The undifferentiated cells contained in this segment, instead of being all employed in the formation of a heterogeneous and coherent structure within the segment, as would be the case in an animal of higher type, proceed very soon to form a second segment, which, instead of separat- ing as a new individual, remains partially attached to the first. This process may go on until hundreds of segments have been formed. Not only, more- over, does spontaneous fission occur in nearly all the orders of the annulose sub-kingdom, but it is a familiar fact that artificial fission often results in the formation of two or more independent animals. So self-sufficing are the parts, that when the common earth-worm is cut in two, each half continues its life as a perfect worm, — as is above observed, in the text. Very siguifi- cant, too, is the fact that in some genera, as in chffitogaster, where the perfect individual consists of three segments, there is formed a fourth segment, which breaks off from the rest and becomes a new animal. All these facts, together wdth many others of like implication, point to the conclusion that the type of annulosa has arisen from the coalescence, in a linear series, of little spheroidal animals primevally distinct from one another. How are we to ex])lain, or classify, such a coalescence ? May we not most plausibly classify it as a fase of arrested reproduction by spontameous fission ! In other words, whereas the aboriginal annuloid had been in the 3i6 COSMIC PHILOSOPHY. [ft. ii. ceans, the parallel chains of ganglia, which constitute the nervous system of the embryo, unite into a single chain. habit of producing by gemmation a second individual which separated itself at a certain stage of growth, there came a time when such separation became an-ested before completion ; so that, instead of a series of independent orga- nisms, the result was a colony of organisms linked together in a linear chain. Let us observe that by this brilliant explanation the origin of the annulose type is completely assimilated to the origin of the lowest animal and vegetal types. The primordial type alike of the vegetable and of the animal, is a single spherical or spheroidal cell, which reproduces itself by spontaneous fission. That is, it elongates until room is made for a second nucleus, after which a notch appears in the cell-wall between the nuclei ; and this notch deepens until the old and new cells are quite separated from each other. Now when many such primordial cells are enclosed in a common membrane, so that, instead of achieving a complete separation, they multiply into a jelly-like or mulberry -like mass, there is formed — whether the case be taken in the animal or in the vegetal kingdom — an organism of a type con- siderably higher than the simple coll. There is an opportunity for differently conditioned cells comprised in the same mass to become differently modified, and thus to subserve various functions in the economy of the organism. There is a chance for division and combination of labour among the parts. Now the progress achieved when the spheroidal members of an annuloid compound remain partly connected, instead of separating, is precisely similar to this. Among the indubitably compound animals of ccelenterate or mol- luscoid tyi^e, in which the fission is not arrested, it is but seldom that the individuals stand related to one another in such a way that there can be any need of their severally performing diverse and specialized functions. For instance, among the hydrozoa, each member of the compound can get food for itself, can expand or contract its tentacles in any way without affecting the general welfare of the compound. But now, if the members of such a compound as the hypothetical primitive annuloid are grouped in a linear series, there must arise a difference between the conditions which affect the extreme members of the series, and the conditions which affect the intermediate members. And consequently there will ensue an advantage to the compound in the struggle for life, if the members, instead of continuing to perform identical functions separately, become sufficiently united to allow of their performing different functions in concert. Hence we obtain the lowest actual type of annuloid, in which the segments are mere repetitions of each other, with the exception of the extreme front and rear segments, which subserve different functions related to the welfare of the aggregate. Viewed in this light, the various great classes of the annulose sub-kingdom beautifully illustrate that progressive coordination of parts becoming more and more unlike one another, which is the chief characteristic of Evolution as displayed in the organic world. In very low annelids, such as the intes- tinal worms, we see hardly any specialization among the parts ; and as we proceed upwards through the lower types, ending with the myriapoda, we meet with a great but varying number of segments, which show but little specialization save in the head and tail. The same is true in general of the lai-vai and caterpillars of the higher types. But as we rise to the adult forms of the insect-group — comprising crustaceans, arachnoids, and true insects— we find the number of segments reduced to just twenty. And while this number remains unvarying, the modifications undergone by different seg- cii. IV. j THM LAW OF EVOLUTION. 347 The same kind of integration may be traced in the nervous systems of insects ; and the reproductive system of the verte- brata furnishes like instances of coalescence which are so conspicuous that they are now usually made one of the primary bases of classification in this sub-kingdom. The reason why Von Baer overlooked this essential process, is pro- bably to be found in the fact that each secondary integration, resulting in increased definiteness, serves to make the accom- panying differentiation still more prominent. The differen- tiation of lungs, for instance, from the outer coat of the endoderm, becomes marked in proportion as the fiower-like buds become integrated into organs of definite contour. But while the two correlative processes go on hand in hand, it is none the less true that they are distinct processes, and that a comprehensive formula of evolution must explicitly describe them both. In further illustration of this twofold aspect of evolution, we may cite a fact which will by and by be seen to have other important bearings, but which may here serve as a valuable appendix to the foregoing discussion. This is the fact that, in ranking different organisms as high or low in the scale of life, we always proceed chiefly with reference to the degree of heterogeneity, definiteness, and coherence which they exhibit. Those plants and animals which we rank as lowest in the scale are simply cells, like the homogeneous cells from which higher plants and animals are developed. So little specialized are these forms that they do not exhibit even those characteristics by which we ordinarily distinguish ments in conformity to the requirements of the aggregate are almost endless in variety, the extremes, both of concentration and of specialization, being seen in the ant, the spider, and tho crab. In many of the details of this gradual fusion of distinct individuals into a coherent whole, we see the hypo- thesis interestingly illustrated and justified. In the annelids of low type, each segment has its own spiracles which have no internal communication with one another. On the other hand, in the insect-group there is a com- plete system of vessels connecting the respiratory systems. While in the intermediate myriapoda we find, as might be expected, a partial communi- cation. 348 COSMIC PHILOSOPHY. [pt. ii. between vegetal 'and animal life. As we aScend the vegetal scale, we find the ferns and lichens decidedly more hetero- geneoiis than the algae ; and as we meet with endogens and exogens, we find the increasing heterogeneity accompanied by a definiteness and coherence of structure that is ever more and more conspicuous. Going up the animal scale,' we find the annulosa, on the whole, much more heterogeneous, definite, and coherent than the mollusca ; while the verte- brata, on the whole, exhibit these characteristics more strik- ingly than either of the other sub-kingdoms. The relatively homogeneous and unintegrated polyps are ranked below all of these. Within each group the same principle of classifi- cation is universally followed. Contrast the centipede, whose multitudinous segments are almost literally copies of each other, or the earth-worm, which may be severed in the middle and yet live, with the highly differentiated and inte- grated hive-bee, spider, or crab. Compare the definite and symmetrical contour of the cuttlefish, which is the highest of the mollusca, with the unshapely outline of the moUus- coid ascidians. Or, to cite cases from the two extremes of the animal scale, consider first the complicated mammS,l, whose growth from the embryo we have lately contemplated ; and then turn to the hydra, or freshwater polyp, which is a mere bag of organized matter, digesting with its inner surface and respiring with the outer, — yet so little specialized that, if turned inside out, the digestive surface will begin to respire, and the respirative surface to digest, as imperturb- ably as if nothing had happened. In short, in a survey of the whole organic world, progress from lower to higher forms is a progress from forms which are less, to forms which are more, differentiated and integrated. One further point must be noticed before we conclude this preliminary sketch of the process of evolution. The illus- trations above given refer almost exclusively to differentia- tions and integrations of sti'udure, or, in other words, to CH. IV.] THE LAW OF EVOLUTION. 349 rearrangements of the matter of whicli organic bodies are composed. It remains to be shown how the rearrangements of the motion retained by developing organisms exhibit tlie same characteristics, and manifest themselves as differentia- tions and integrations of function. All organic functions are either molar motions of contractile muscles, or of circulatory fluids, or else they are molecular motions in nerves, or in secreting organs, or in assimilative tissues in general. To show how these various motions become more specialized and more consolidated as the organism is developed, let us briefly reconsider the case of the alimentary canal, whose structural modifications were lately described. The primitive alimentary canal exhibits from end to end a tolerably uni- form series of molar motions of constriction. But as the canal becomes more heterogeneous, the molar movements in its different parts simultaneously become more unlike one another. Wliile the waves of contraction and expansion remain constant and moderate throughout the small in- testine, they are replaced in the oesophagus by more violent contractions and expansions that recur at longer rhythmical intervals. In the stomach the mechanical undulations are so much more powerful as to triturate the contained food, and their rhythms are differently compounded ; while the movements of the mouth are still further specialized in the actions of biting and chewing. In the molecular motions constituting secretion and absorption there is a similar specialization. While absorption is confined chiefly to the area covered by the lacteals, secretion is specialized in various localities — in the salivary glands, in the gastric and intestinal follicles, in the liver, and in the pancreas — and in each place it has acquired a peculiar character. A like increase in heterogeneity and definiteness marks the circu- latory movements. In a slightly-evolved animal the nutri- tive fluid, answering to blood, moves about here and there at seeming random, its course being mainly determined by the 350 COSMIC PHILOSOPHY. [pt. ii. local pressure of the tissues. But in a highly-evolved animal, which possesses a well-developed vascular system, the blood runs in definite channels, and with well-marked differences of movement. Its movement is slow and con- tinuous in the capillaries, fast and continuous in the veins, still faster hut discontinuous in the arteries ; while the rhythms in all are sulonrdinated by the central rhythm of the heart. Still more remarkable, in the most complex organisms, is that kind of functional integration which consists in the mutual dependence of different functions. Neither alimentation nor circulation nor respiration can go on alone ; and all three are dependent upon the continuance of nervous action, which in turn depends alike upon each of the three. A few whiffs of tobacco, for example, setting up slight molecular changes in the medulla oblongata, increase the heart's rate of pulsation, and stimulate every one of the alimentary secretions, while it is probable also that, through the medium of the sympathetic ganglia, the sectional area of every artery is slightly altered. The cautious physician, in prescribing a powerful drug, knows that he is dealing with an integration of motions so extensive that the disturbance of any one will alter the directions and composition of all the others to a degree which baffles accurate calculation. Contrasting with such cases as these the homogeneous, inde- finite and uncombined movements of those lowest animals, that are borne hither and thither by the vibrations of cilia, it becomes evident that the formula which expresses the structural evolution of matter, expresses also the functional evolution of the motion which the integrating matter retains. Embracing now in one general view the various kinds of transformation exemplified in the present chapter, we find that our survey of organic development completely justifies Mr. Spencer's technical statement: — "Evolution is an inte- gration of matter and concomitant dissipation of motion ; CH. IV.] THE LAW OF EVOLUTION. 351 during which the matter passes from an indefinite, incoherent homogeneity to a definite, coherent heterogeneity ; and during which the retained motion undergoes a parallel trans- formation." ^ Here, it will be observed, we have obtained a formula which applies not to organic development merely, but to the transformations of Matter and Motion in general. Though we have been led to it solely by the consideration of those organic phenomena which, for reasons already presented, most conspicuously exemplify it, and in con- nection with which it was first partially generalized by Goethe and Von Baer ; yet now that we have arrived at this formula, we find ourselves expressing it in terms that are universal. Instead of a mere law of biology, we have enunciated the widest generalization that has yet been reached concerning the concrete universe as a whole. Having ascertained that in organic aggregates, where the conditions are such as to allow of relatively permanent structural rearrangements, the process of Evolution is cha- racterized by a change from indeterminate uniformity to determinate multiformity, we have assumed that like con- ditions will everywhere be attended with like results. The law asserts that wherever a relatively permanent system of rearrangements is possible, whether in organic or in in- organic aggregates, the change from indeterminate uniformity to determinate multiformity will be manifested. This leap of inference on Mr. Spencer's part, like the similar leap taken by Newton from the fall of the apple to the motions of the moon, is the daring act which completes the formation of the hypothesis. This grand hypothesis we must now proceed to verify by showing that the widest generalizations severally obtainable in the concrete sciences are included in it, and receive from it their common interpretation. It is to be shown that in the case of sundry inorganic aggregates or ^ First Principles, p. 396. 352 COSMIC PHILOSOPHY. [pt. ii. systems of parts (forming the subject-matter of astronomy and geology), where circumstances not yet recounted permit the retention of a considerable relative motion of parts, the processes of differentiation and integration are quite con- spicuously manifested ; although, as we might expect, these processes are never carried so far here as in the case of organic aggregates. It will next be shown that the hypo- thesis is verified, alike by the scanty facts which are at our disposal concerning the genesis of Life, and by the enormous multitude of facts which prove beyond the possibility of doubt that the more complex living creatures have ori- ginated by physical derivation from ancestral creatures that were less complex. ISText, although— as I have already remarked — the phenomena of Mind are in uo sense identi- fiable with material phenomena, yet as in all our experience there is no manifestation of Mind which is not mysteriously conditioned by movements of matter, we shall find that these super-organic phenomena do not fail to conform to the universal law. Tt will be shown that the development of conscious intelligence, alike in the individual and in the race, is characterized by the change from indeterminate uniformity to determinate multiformity. The history of the products of conscious intelligence exemplify the same principle ; and nowhere shall we find more striking confirmation than is furnished by the phenomena of social progress. By the time we have narrated the results of this vast induction, we shall be convinced that " from the earliest traceable cosmical changes down to the latest products of civilization," the law of organic evolution here expounded is the law of all evolution whatever. But the universality of this law admits of deductive proof, which may properly be adduced while concluding this chapter, and before entering upon the long course of inductive veri- fication which comes next in order. Already we have seeu that the changes which primarily constitute Evolution are CH. IV.] THE LAW OF evolution: 353 necessitated by the rhythm of motion, and therefore in- directly by the persistence of force. We have now to show how the secondary changes, differentiation and integration, are equally necessitated by the same primordial fact. It is a coroUary from the persistence of force, "that, in the actions and reactions of force and matter, an unlikeness in either of the factors necessitates an nnlikeness in the effects." When the different portions of any homogeneoiis aggregate are exposed to the action of unlike forces, or to unequal intensities of the same force, they are of necessity differently affected thereby. Between the unequally exposed parts there arise structural differences, entailing differences of property and function. That which before was homo- geneous has become heterogeneous through the appearance of certain unlikenesses ; and, under the name of differentia- tion, the rise of such unlikenesses has already been described. It remains to be observed that such unlikenesses cannot but arise, that differentiation must needs take place, because it is impossible for all the parts of any aggregate to be similarly conditioned with reference to any incident force. Whether it be the mechanical vibrations caused by a blow, the slow undulations constituting heat, or the more rapid undulations constituting light, that are propagated through any body, it equally follows that the respective vibrations will be com- municated in different degrees to those particles whicli are situated on the nearer and on the farther side of the body, and to those particles which are laterally near to or remote from the line followed by the incident force. The different parts will be variously moved, heated, or chemically affected, and a series of differentiations will thus have arisen. We need "o no farther than the kitchen, to perceive that the crust formed on a loaf of bread or a joint of roasted meat, is due to the necessarily unequal exposure of outside and inside to the incident force coming in the shape of heat from the walls of the oven. In the impossibility of balancing an VOL. I. A A 354 COSMIC PHILOSOPHY. [pt. ii. accurately made pair of scales, in tlie equal impossibility of keeping a tank of water free from currents, in the rusting of iron, and in the uneven cooling of a heated metal, is exem- plified the principle that the state of homogeneity is an imstable state. Universally the tendency of things, amid the conflict of unlike forces, is toward heterogeneity. Coincident with the differentiation of aggregates, there is a differentiation of the incident forces. When a moving body is broken up by collision, its original momentum is severed into a group of momenta, which differ both in amount and in direction. The ray of solar light which falls upon the foliage of a tree and upon the wall of the brick building behind it, is separated by reflection into red and green rays, in which the undulations differ both in height and in breadth. Each portion of the differentiated force must in its turn enter as a factor into new differentiations, The more heterogeneous an aggregate becomes the more rapidly must differentiation go on ; because each of its component units may be considered as a whole, bearing relations to the other units similar to those which the aggregate bears to other aggregates ; and thus the differentiation of the whole must be followed by the differentiation of the parts. There must thus be a multiplication of effects as heterogeneity increases ; because, with increasing heterogeneity, the forces which bodies and parts of bodies mutually exert upon each other must become ever more varied and complex in their amounts and directions. We may see, therefore, that differentiation is a necessary consequence of the fundamental relations of matter and motion. And the same is true of that secondary integration or union of like units, which serves to render differentiation more conspicuous by substituting a demarcated grouping for a vague one. Considering what happens when a handful of pounded sugar, scattered before the breeze, falls here and there according to the respective sizes of the fragments, — we perceive that the units which descend in company are those CH. IV.] THE LAW OF EVOLUTION. 355 of equal size, and that their segregation results from their like relations to the incident force. The integration of several spinal vertebrae into a sacrum, as the result of exposure to a continuous strain in the same direction, is a still better example ; and from the phenomena of morphological develop- ment many parallel cases might be cited. "Wherever dif- ferent parts of any group of units stand in different relations to an incident force, differentiation must result ; and wher- ever any sub-group of these units, after becoming unlike the rest, is acted on by a common force, the result must be the integration of the sub-group. But manifestly the pri- mary process of consolidation cannot long go on in any aggregate, without bringing sundry groups of units into dissimilar relations to adjacent groups ; nor can it long go on without subjecting each group, thus differentiated, to a pre- dominant force exerted by the totality of the companion- groups. Hence the change from indefinite incoherent homo- geneity to definite coherent heterogeneity must accompany the integration of matter ; and no alternative conclusion can be reached without denying the persistence of force. I am aware that scanty justice is here done to the argu- ments by which, in three interesting chapters, Mr. Spencer establishes this deductive conclusion. But since the brief exposition here given is not intended as a substitute for the study of Mr. Spencer's treatise, but rather as a commentary upon it, his position has been perhaps sufficiently indicated. We are now prepared to study with profit some of the phenomena presented by the past history of our planetary system. In the evolution of the sun, with his attendant planets and satellites, from a vast primeval mass of vapour, we shall be called upon to witness a grand illustration not only of that integration of matter and concomitant dissipation of motion which is the fundamental characteristic of Evo- lution in general, but also of that change from indefinite and incoherent homogeneity to definite and coherent hetero- geneity which is its most striking derivative feature. A A 2 CHAPTER V. PLANETAKY EVOLUTION. Among the notable phenomena presented by the structure of our planetary system, there are some which have become so familiar to us that we commonly overlook them altogether, and through sheer inattentiveness fail to realize their signifi- cance. For example, all the planets revolve about the sun in the same direction, which coincides with the direction of the sun's own rotation upon his axis. All the planets, more- over, revolve in planes which are but slightly inclined to the plane of the sun's equator. Satellites conduct themselves similarly with reference to their primaries. Every satellite revolves about its primary in the direction of the primary's axial rotation, and in a plane but little inclined to the plane of the primary's equator. Again, with tlie single interesting exception of Uranus— and possibly also of Neptune — all the planets, as well as the sun, rotate upon their axes from west to east, in the same direction with their orbital revolutions. And lastly, all the planets, both primary and secondary, move in elliptical orbits of small or moderate eccentricity. We are so accustomed to acquiesce in these facts, as if they were ultimate, that we seldom stop to consider them in their true light, as unimpeachable witnesses to the past CH. v.] PLANETARY EVOLUTION. 357 history of the solar system. Yet as Laplace has shown, it is practically impossible that such harmonious relations should hold between the various members of the solar system, unless those members have had a common origin. The clue to that common origin may be sought in facts which are daily occurring before our very eyes. Every member of our planetary system is constantly parting with molecular motion in the shape of heat. Our earth is incessantly pouring out heat into surrounding space ; .^nd, although the loss is temporarily made good by solar radia- tion, it is not permanently made good, — as is proved by the fact that during many millions of years the earth has been slowly cooling. I do not refer to the often-cited fact that the Arctic regions were once warm enough to maintain a tropical vegetation ; for this high temperature may well have been due to minor causes, such as the greater absorptive power of the ancient atmosphere with its higher percentage of carbonic acid and ozone. Nor need we insist upon the alleged fact that extensive glaciation appears to have been unknown until a comparatively late epoch ; although glacia- tion, whether brought about by changes in the distribution of land and sea or by a variation in the eccentricity of the earth's orbit, certainly does seem to imply a progressive dependence of the earth upon the supply of solar heat, due to the lowering of its own proper temperature. Such facts, however, are wholly inadequate to describe the primitive heat of the earth. The flattening of the poles being con- siderably greater than could have been produced by the rotation of a globe originally solid on the surface, it follows that the whole earth was formerly fluid. And this conclu- sion, established by dynamical principles, is uniformly corroborated by the observed facts of geology. Now the fluidity of the entire earth, with its rocks and metals, implies a heat sufficient to have kept the planet incandescent, so that it must have shone with light of its own, like the 358 COSMIC PHILOSOPHY. [pT. ii. stars. Similar conclusions are indicated by the observed geologic features of Mars and Venus ; and in the case of the moon we shall presently see what a prodigious loss of heat is implied by the fact that the forces which once upheaved its great volcanoes are now quiescent. The sun, too, is pouring away heat at such a rate that, according to Sir John Herschel, if a cylinder of ice 184,000 miles in length and 45 miles in diameter were darted into the sun every second, it would be melted as fast as it came. Or, as Mayer has calculated, the amount of heat lost every minute by the sun would suffice to raise the temperature of thirteen biUion cubic miles of water one degree Centigrade. Although this prodigious loss is perhaps partly compensated by heat due to the arrested motion of meteors falling upon the sun's surface, yet it is by no means probable that it is in this way compensated to any noteworthy extent. It is in every way indisputable that from time immemorial sun, moon, and earth, as well as the other members of our system, have been parting with their internal motion, in the shape of heat radiated into surrounding space. Thus in the history of our planetary system we may already begin to witness that dissipation of motion which has been shown to be one of the prime features of the process of Evolution, wherever exemplified. But, as we have also seen, the dissipation of motion is always and necessarily accompanied by the concentration of matter. It is not simply that, with two or three apparent exceptions, which have no bearing upon the present argument, all cooling bodies diminish in size and increase in density ; but it is also that all contracting bodies generate heat, the loss of which, by radiation, allows the process of contraction to continue. In any contracting mass the particles which tend toward the common centre have their molar motions con- stantly opposed by friction upon each other, and most of the motion thus arrested is converted into heat. If this heat is CH. v.] PLANETARY EVOLUTION. 359 lost by radiation as fast as it is thus generated, the contrac- tion of the mass will go on unceasingly. It is in this way that physicists now account for the internal heat of the sun and the planets. A diminution of the sun's diameter by the amount of twenty miles could not be detected by the finest existing instruments ; yet the arrest of motion implied in this slight contraction would generate enough heat to maintain the present prodigious supply during fifty centuries. And in similar wise the internal heat of the earth during a given moment or epoch must be chiefly due to that very contraction which the radiation of its heat during the preceding moment or epoch has entailed. The generation of all this heat, therefore, which sun and planets have from time immemorial been losing, implies the transformation of an enormous quantity of molar motion of contraction. It implies that from time immemorial the various members of our planetary system have all been decreasing in volume and increasing in density ; so that the farther back in time we go, the larger and less solid must we suppose them to have been. This is an inevitable corollary from the companion laws that contracting bodies evolve heat, and that radiating bodies contract. Obviously, therefore, if we were to go back far enough, we should find the earth filling the moon's orbit,^ so that the matter now composing the moon would then have formed a part of the equatorial zone of the earth. At a period still more remote, the earth itself must have formed a tiny portion of the equatorial zone of the sun, which then filled the earth's orbit. At a stiU earlier date, the entire solar system must have consisted simply of the sun, which, more than 1 It is not presumed, towever, that the moon's orbit was originally so large as at present. For by its tidal action upon our oceans the moon exerts a drag upon the earth's rotation, and the motion thus lost by the earth is added to the moon's tangential momentum, thus increasing the dimensions of its orbit. A precisely similar qualification is needed for the two next-succeeding state- ments in the text. 360 COSMIC PHILOSOPHY. [pt. n. filling Neptune's orbit, must have consisted of diffused vaporous matter, like that of which the irresolvable nebulse have recently been proved to consist. Now in the slow concentration of the matter constituting this solar nebula, as both Kant and Laplace have elaborately proved, the most prominent peculiarities of the solar system find their complete explanation. Supposing the sun to have been once a mass of nebulous vapour, extending in every direction far beyond the present limits of the solar system, these thinkers proved that the mere contraction of such a mass must inevitably have brought about just the state of things which we now find. Let us observe some of the processes which must have taken place in this nebulous mass. Note first that we are obliged to accredit the various parts of this genetic nebula with motions bearing some reference to a common centre of gravity ; for the rotation of the resulting system must have had an ec[uivalent amount of motion for its antecedent, and it is a well-known theorem of mechanics that no system of bodies can acquire a primordial rotation merely from the interaction of its own parts. In making this assumption, however, we are simply carrying out the principle of the continuity of motion. It is not necessary to suppose, in addition, that all these motions primordially con- stituted a rotation of the whole mass in one direction. Such a hypotliesis seems to me not only gratuitous, but highly im- probable. It is more likely that these primeval motions took the shape of currents, now aiding and now opposing one another, and determined hither and thither according to local circumstances. In any case, such indefiniteness of movement must finally end in a definite rotation in one direction. For unless the currents tending eastward are exactly balanced by the currents tending westward — a supposition against which the chances are as infinity to one — the one set must eventually prevail over the other. And after some such CH. v.] PLANETARY EVOLUTION. 361 manner as this our solar nebula must have acquired its definite rotation from west to east. Let us next observe the mechanical consequences of this rotation. ISTo matter what may have been the primitive shape of the nebula — and, if we may judge from the analogy of irresolvable nebulse now existing, it may very likely have been as amorphous as any cloud in a summer sky — no matter what its primitive shape, it must at last inevitably assume the form peculiar to rotating bodies in which the particles move freely upon each other. It must become an oblate spheroid, flattened at the poles and bulging at the equator, because at the equator the centrifugal tendency generated by rotation is greatest. Furthermore as the mass contracts, it must rotate faster and faster; for as the total quantity of rotation is unalterable, the velocity must increase as the space traversed diminishes. In accordance with these principles of mechanics, as our solar nebula continued to radiate heat and contract, it con- tinued to rotate with ever-increasing velocity, its poles became more and more flattened, and its equatorial zone pro- truded more and more, until at last the centrifugal tendency at the equator became greater than the force of gravity at that place. Then the bulging equatorial zone, no longer able to keep pace with the rest of the mass in its contraction, was left behind as a detached ring, girdling, at a small but steadily increasing distance, the retreating central mass. What must now have been the career of this detached ring ? Unless subjected to absolutely symmetrical forces in all directions — an infinitely improbable supposition — such a ring must forthwith break into a host of fragments of very imequal dimensions. For in order that it should break into equal-sized fragments, the strains exerted upon it must be disposed with absolute symmetry; and against this supposition also the probabilities are as infinity to one. It would break, much as a dish breaks when dropped on the floor, into 362 COSMIG PHILOSOPHY. [pt. ii. hundreds of fragments, of which some few would be rela- tively large, while the numerous small ones would vary end- lessly in their sizes. At this stage, then, instead of a con- tinuous riug, we have a host of satellites, surrounding the solar equator, revolving in the direction of the solar rotation, and following each other in the same orbit. If undisturbed by any powerful attraction from without, these fragments would continue in the same orbit, and would gradually differ more and more in their velocities. Each large fragment would, by its gravitative force, retard the smaller fragment in front of it, and accelerate the smaller fragment behind it, until at last two or three fragments would catch up with each other and coalesce. Thus, in the earliest case known to us, — that of the planet Neptune,^ — this process went on until all the fragments were finally agglomerated into a spheroidal body, having a velocity compounded of the several velocities of the fragments, and a rotation made up of their several rotations. Meanwhile the central mass of the vaporous sun continued to radiate heat and to contract, until, when its periphery came to coincide with what is now called the orbit of Uranus, its centrifugal force at the equator again showed an excess over gravity, and a second equatorial belt was left behind ; and this belt, breaking up and consolidating, after the manner above described, became the planet Uranus. In like manner were formed all the planets, one after another ; and from the detached equatorial belts of the cooling and contracting planets, were similarly formed the satellites. A very curious physical experiment, devised by M. Plateau, strikingly illustrates the growth of our planetary system from 1 It is not strictly impossible that there may be one or two planets exterior to Neptune, and therefore earlier in formation. Supposing the distances of such planets to conform, even as imperfectly as in Neptune's case, to the law of Titius, these distances must be so enormous as to prevent our readily dis- covering the planets, either directly by observation, or indirectly, by infer- ence from possible perturbations of Neptune's movements. CH. v.] PLANETARY EVOLUTION. 363 the aolar nebula. M. Plateau's experiment consists in freeing a fluid mass from the action of terrestrial gravity, so that its various parts may be subject only to their own mutual attractions ; and then in imparting to this mass an increas- ingly rapid movement of rotation. A quantity of oil is poured into a glass vessel containing a mixture of water and alcohol, of which the lower strata are heavier than the oil, while the upper strata are lighter. The oil, when poured in, descends until it reaches the stratum of the same density with itself, when being freed from the action of terrestrial gravity, and subjected only to the mutual attraction of its own molecules, it assumes a spherical form. By an ingenious mechanical contrivance, M. Plateau now causes the sphere of oil to rotate about its own centre of gravity. While the movement is slow, the excess of centrifugal force at the equator of the oil-globe causes a bulging of the equator and corresponding flattening of the poles, like that observed in the sun and in aU the planets. From a sphere the oil- globe becomes a " spheroid of rotation." If now the move- ment is considerably accelerated the equatorial portion of the oil-globe becomes detached, and surrounds the central sphere of oil in the shape of a nearly circular ring, like Saturn's ring-system. Finally, if the movement is kept up for a sufiieient length of time, the oil-ring breaks into fragments, which revolve like satellites about the oil- globe, and each of which keeps up for a time its own move- ment of rotation in the same direction with the revolution of the ring. The common origin of the planets from the sun's equator, as thus strikingly illustrated, explains at once the otherwise inexplicable coincidence of their rotations, their revolutions, and their orbital planes. At a single glance we see why the planetary orbits are always nearly concentric and nearly in a plane with the solar equator ; and we see that, since the sun must always have rotated, as at present, from west to east, 364 COSMIC PHILOSOPHY. [pt. ii. the planets formed from him must have kept up a revolution, and acquired a rotation, in the same direction. Such is the grand theory of nebular genesis, first elabo- rated with rare scientiiic acumen by Kant in 1755, and after- wards independently worked out by Laplace in 1796. The claims of this theory to be regarded as a legitimate scientific deduction have been ably stated by Mr. Mill, in his " System of Logic," book iii. chapter xiv. As we are there reminded, " there is in this theory no unknown substance introduced on supposition, nor any unknown property or law ascribed to a known substance." Once grant that the sun and planets are cooling bodies, the inference is unavoidable that the matter which composes them was formerly much more rare and dif- fused than at present. If we are to infer the sun's past con- dition from its present condition, we must necessarily sup- pose that its constituent matter once occupied much more space than at present, " and we are entitled to suppose that it extended as far as we can trace effects such as it might naturally leave behind it on retiring ; and such the planets are." The abandonment of successive equatorial zones by the shrinking solar nebula follows from known mechanical laws ; and the subsequent breaking up of each zone, and the consolidation of its fragments into a planet, are processes which similarly involve none but established dynamical prin- ciples. It equally follows, from elementary laws of mecha- nics, that the planets thus formed would revolve and rotate both in the directions and in the planes in which they are actually observed to revolve and to rotate. There is thus, observes Mr. Mill, nothing gratuitous in Laplace's specula- tion : " it is an example of legitimate reasoning from a present effect to a possible past cause, according to the known laws of that cause." But the evidence in favour of the theory of nebular genesis is not restricted to these general coincidences between obser- vation and deduction. Many striking minor details in the cii. v.] PLANETARY EVOLUTION. 365 structure of the solar system, otherwise apparently inexpli- cable, are beautifully explained by the theory of nebular genesis. Let us first consider a case which would appear to be an obstacle, not only to this, but to any other frameable theory. We have already hinted that Uranus, while revolv- ing in the same direction with the other planets, has a back- ward rotation, so that to an observer placed upon Uranus the sun would seem to rise in the west and set in the east. His moons revolve about him in the same retrograde direction ; and his axis, instead of standing at a great angle to his orbit- plane, as is the case with all the nearer planets, lies down almost upon the orbit-plane. It has been asserted that these peculiarities are also manifested by Neptune; though our opportunities for observing the latter planet are so few that this point cannot yet be regarded as established. Why now should such exceptional phenomena be manifested in the case of either or both of these outermost planets? In his essay on the Nebular Hypothesis, Mr. Spencer has shown that these phenomena may be explained by a reference to the shape of the rings from which the outermost planets were formed. When the solar nebula was so large as to fill the orbit of Neptune, its rotation must have been slower, and its figure consequently less oblate, than at later stages of con- traction. Now the ring detached from a very oblate spheroid, which bulges greatly at the equator, must obviously be shaped like a flat quoit, as is the case with Saturn's rings ; while conversely the ring detached from a spheroid which bulges comparatively little at the equator, will approximate to the shape of a hoop. Hence the rings which gave rise to Neptune and Uranus, having been detached before the solar nebula had attained the maximum of oblateness, are likely to have been hoop-shaped; and when we consider the enormous circumferences occupied by these rings, compared with the moderate sizes of the resulting planets, we see that they must have been very thin hoops. Now in such a hoop 366 COSMIC PHILOSOPHY. [ft. ii. the angular velocities of the inner and outer surfaces re- spectively win be nearly equal, and the planetary mass into which such a hoop concentrates wiU have its greatest diameter at right angles (or nearly so) to the plane of its orbit ; so that its tendency to rotate in the line of its revolution will be so slight as to be easily overcome by any one of a hundred possible disturbing circumstances. Without feeling required to point out the precise nature of such circumstances, we may readily see that, in the case of the outermost planets, the causes which ordinarily make the rotation coincide with the line of revolution were at their minimum of efficiency. So that the retrograde rotation of Uranus, though not perhaps actually implied by the hooped shape of its ancestral ring, is at any rate quite in accordance with it. I cite this example, not merely on its own account, but also by reason of the further disclosures to which it leads us. Whatever may be thought of the special interpretation just cited, there is no doubt that Mr. Spencer's conception of hoop-shaped and quoit-shaped rings points to a notable series of harmonies among the phenomena of the solar system. Observe, first, that according to the theory, the outer planets ought in general to be much larger than the inner planets ; and for a very simple reason. The ancestral rings which coincided with the immense orbits of Uranus and Neptune must of course have been larger than the ancestral rings which coincided with the smaller orbits of Mars and the earth. A ring, for example, which is seventeen thousand millions of miles in circumference may be expected to con- tain more matter than a ring which is less than six hundred millions of miles in circumference; and hence we may understand why Neptune contains at least sixteen times as much matter as the earth. But this, though significant, is not a complete explanation ; for as the case now stands, it would seem as if there ought to be a regular gradation in the sizes of the planets. Not CH. v.] PLANETARY EVOLUTION. 367 only ought Mercury to be the smallest, but Neptune ought to be the largest. The facts, however, do not accord with this view. The four outer planets are indeed much larger than the four inner ones. But of the inner group the largest is not Mars, but the earth ; while in the outer group we find Jupiter three-and-a-half times as large as Saturn, which in turn is seven times larger than Uranus. Now the key to these apparent anomalies must, I think, be sought in the shapes of the rings from which the planets were respectively formed. Neptune and Uranus, formed from very thin hoop- like rings, at a period when the solar equator protruded but slightly, are indeed large planets, but not so large as would be inferred from the size of their orbits alone. But as the solar nebula continued to contract, its increasing equatorial velocity rendered it more and more oblate in figure, so that the rings next detached were quoit-shaped. Hence the resulting planets not only had their major diameters but little inclined to their orbit-planes, but they were also larger in size. The very broad quoits which gave rise to Jupiter and Saturn may well have contained more than fourteen times as much planetary matter as the extensive but slender hoops which formed the two oldest planets. If instead of looking at the sizes of the resulting planets, we consider the thick- nesses of the genetic rings, as determined by comparing the size of a planet with the size of its orbit, we shall see that, from Neptune to Jupiter, there was a regular increase in the thickness of the rings, such as the theory might lead us to anticipate. But now after the separation of Jupiter from the parent- mass, we encounter a break in this series of phenomena. The thickness of the detached rings sinks to a minimum in the case of the asteroids, and then steadily increases again until in Mercury there is once more an approach to the quoit- shape. Observe the curious sequence of facts, which hitherto, so far as I know, has never been noticed by any of the writers 368 OOSMIG PHILOSOPHY [pt. ir. who have treated of the nebular hypothesis. Since the mass of Mercury is four-fifths that of Venus, while the circumference of his orbit is about one-half that of the orbit of Venus, it follows that his ancestral ring must have been much thicker than that of Venus. Again, the earth is but little larger than Venus, while the circumference of its orbit exceeds that of the latter nearly in the ratio of five to three, so that it must have originated from a thinner ring. Mars, with an orbit exceeding the earth's in the ratio of eight to five, and containing but one-eighth as much planetary matter as the earth, must have been formed from a stiU thinner ring. And since the asteroids, if all piled together, would not make a planet as large as Mars,i while they move through a very much greater orbit, it follows that their parent-ring must have been the thinnest of all. In marvellous conformity to this general statement, it also happens that the inner planets rotate in planes which diverge more widely from their orbit-planes than in the case of Jupiter and Saturn, though less widely than in the case of Uranus and ISTeptune.^ And lastly let us note that the velocities of the planetary rotations supply ^ It may be objected that we have probably not yet discovered all the asteroids. Those not yet discovered, however, must obviously be so small that the addition of them to the aggregated mass of those already known would not materially affect the truth of my statement. 2 Curiously enough, if we examine the different systems of satellites, we find a similar general contrast in size between the members of outer and inner groups. The two outer satellites of Jupiter are much larger than the two inner ones ; and the same relation holds between the four acknowledged satellites of Uranus ; while of the eight Saturnian satellites, the four outer ones seem to be decidedly larger than the four inner ones. Moi cover the largest of Jupiter's moons is not the outermost, but the third ; and of Saturn's moons the largest is not the eighth, but the sixth. To these inte- resting facts which Mr. Spencer has pointed out, I will add one which he has not observed. If instead of looking at the sizes of the moons, we consider the thicknesses of their genetic rings, as determined by comparing the size of a moon with the size of its orbit, we find in the Jovian system a regular in- crease in the thickness of the rings, from the outermost to the innermost. Similar evidence from the Saturnian system is not yet forthcoming, since the masses and even the volumes of Saturn's moons have not yet been determined with sufficient accuracy for this purpose. And concerning the Uranian system our knowledge is still more inadequate. It will be observed, how- ever, that even the facts here fragmentarily collated point clearly to some OH. v.] PLANETARY EVOLUTION. 3ti9 further confii'mation ; for " other things equal, a genetic ring that is broadest in the direction of its plane will produce a mass rotating faster than one that is broadest at right angles to its plane " ; and accordingly JiTpiter and Satui'n, originating from relatively quoit-shaped rings, rotate very swiftly ; while all the inner planets, originating from relatively hoop-shaped rings, rotate with much less rapidity. Here we may profitably consider tlie singular instance in the history of the solar system in which a detached ring has failed to become integrated into a single planetary mass. Everyone remembers how, in accordance with the law of Titius concerning planetary intervals, Kepler was led to pre- dict the existence of a planet between Mars and Jupiter ; and how, at the beginning of the present century, not one only, but four such planets, were suddenly discovered. More than a hundred of these little bodies have now been detected, and each year adds new names to the list. The four earliest observed — Vesta, Juno, Ceres, and Pallas — are of respectable dimensions ; Pallas having a diameter of 600 miles, or more than one fourth the diameter of our moon. Most of the others are quite tiny, the smallest having a surface perhaps not larger than the state of Ehode Island. Not only do they occupy the position which would normally belong to a single planet between Mars and Jupiter, but it is hardly question- able that they have all originated from a single ring ; for their orbits are interlaced in such a complicated way that, if they were material rings instead of ideal lines in space, it would be possible to lift them all up by lifting any one of them. Why should just one of the solar rings have failed to develope into a single planet, and why should such an arrest of development have occurred in just this part of the solar system ? common mode of genesis for both planets and satellites ; and are likely, when completely geiier.ilized, to yield important testimony in behalf of the nebular tlieory. VOL. I. KB 370 COSMIC PHILOSOPHY. [pt. ii. According to Olbers, the discoverer of Pallas and Vesta, this is not a case of arrested development, but these little bodies are merely the fragments of an ancient well-developed planet, which has been in some way exploded. But this hypothesis, though countenanced by Mr. Spencer, seems to me unsatisfactory. In Mr. Spencer's essay, it is closely con- nected with the hypothesis of a gaseous nucleus for all the planets, which, though there ingeniously elaborated, seems to me as yet too doubtful to serve as a basis for further explana- tions. And even granting the hypothesis, it would be necessary further to show why in this planet alone the out- ward pressure of the gaseous nucleus should have overcome the resistance of the solidified crust. I believe that the problem is much nearer a solution when we treat it as a case ol arrested development; for on this view the peculiar fate of the ancestral ring may be at least partially explained by a reference to the perturbing attraction exerted upon it by Jupiter. When we reflect upon the immensity of the distances which separate the outer planets from each other, even in conjunction, we perceive that during the earlier stages of nebular contraction no planet was in danger of being dis- turbed in its formation by the attraction of its next outer neighbour and predecessor. But as the increasing equatorial protuberance of the solar spheroid began to result in the formation of larger and larger planets, and as the formation of planets began, according to the law of Titius, to occur, at shorter and shorter intervals, there began to be some danger of such disturbance. There was no chance for a catastrophe, however, until the time when the asteroid-ring was detached. The enormous Jupiter-ring was at least 370,000,000 miles removed from Saturn, besides which its huge mass, implying powerful gTavitative force among its constituent parts, served further to insure its equilibrium. Hence it ran little risk of incurring disaster in the course of its planetary development. CH. v.] PLANETARY EVOLUTION. 371 It was otherwise with the ancestral ring of the asteroids. This thinnest and weakest of rings started on its independent career at a distance of only 240,000,000 miles from Jupiter, the planet whose gravitative force is more than twice that of all the other planets put together. Under such circumstances it would seem impossible that a planet could he formed. The asteroid-ring must have been liable to rupture, not only from the causes which affect all planet- forming rings alike, but also from the strain exerted upon it, now in one part and now in another, by Jupiter's attraction. The fragments of a ring, torn asunder by such a cause, would not continue to occupy the same orbit ; they would be dragged from the common path in various directions and to various distances, according to the ever- changing position of the disturbing body. Henceforward, instead of chasing directly on each other's heels, they would rush along in eccentric, continually intersecting paths, and there would thus be no opportunity for consolidation, except in the case of two fragments meeting each other at the intersection of their orbits. As a iinal result we sliould have, not one good-sized planet, but a multitude of tiny planets, with intersecting orbits exhibiting great differences in eccentricity. All this is true of the group of asteroids. While the mean breadth of the ideal zone occupied by their orbits is about 100,000,000 miles, its extreme breadth reaches 250,000,000 miles. While the orbit of Europa is more nearly circular than any of the orbits of the true planets, on the other hand the orbit of Polyhymnia attains an almost cometary eccentricity, the difference between its perihelion and aphelion being nearly 200,000,000 miles. There is one other circumstance, however, which my hypothesis thus far fails to explain. While the true planets revolve in planes but slightly inclined to the ecliptic — the orbit of Mercury showing an inclination of about seven decrees as the maximum instance — the asteroids, on the con- B B 2 372 COSMIC PHILOSOPHY. [pt. n. trary, revolve in planes of quite various degrees of inclina- tion, the orbit of Pallas rising above the ecliptic at an angle of thirty-four degrees. As the disturbing attraction of Jupiter, however various in direction, would seem to have been exerted wholly in one plane, I am unable to account for this diversity of inclinations. Yet in spite of this short- coming in the hypothesis — which might perhaps be removed by some one more thoroughly conversant with dynamics — all the other circumstances in the case point unmistakeably to the forcible rupture of the genetic ring by the attraction exerted by Jupiter; and thus it would seem that, just when such an untoward event in the history of the solar system might have been expected to occur, it did occur. Supposing this explanation to be sound in principle, it is quite easy to show why such an event has not occurred sub- sequently. The next ring — the one wliicli gave rise to Mars — must have been more than twice as thick as the genetic ring of the asteroids, and consequently better fitted to resist a strain from without. And, moreover, being 115,000,000 miles farther removed from Jupiter, the latter planet could exert upon it only four-ninths of the disturbiugforce which it liad exerted upon the asteroid-ring. Thus the Mars-ring was permitted to develope into a planet. In turn, the small size of Mars prevented him from exerting any disastrous perturbing force upon the ring which gave rise to the earth, though his distance from that ring could not have exceeded 50,000,000 miles. A simple computation will show that Mars could exert upon the earth-ring not much more than one-hundredth part of the attraction exercised by Jupiter upon the ances- tral ring of the asteroids. On the other hand, had the mass of Mars been one twenty-fifth as great as that of Jupiter — that is, thirteen times as great as the mass of the earth — he might have prevented the formation of the planet on which we live. And had the mass of Mars been equal to that of Jupiter, he might have dealt destruction to all the planetary CH. v.] PLANETARY EVOLUTION. 373 rings subsequently detached between himself and the present solar surface. The earth, Venus, and Mercury would in such a case have been represented by a triple zone of asteroids, revolving in more or less eccentric orbits, and the portions of planetary matter which constitute the German armies belea- guering Paris might to-day^ have been peacefully whirling in space, ten million miles removed from the portions which constitute the starving population of that unhappy city. Joining together aU the foregoing considerations, we have a most interesting array of facts, which I believe liave not hitherto been contemplated in connection with one another. Though in the sizes of the planets, superficially regarded, we find no conspicuous symmetry of arrangement, yet in the thickness of the genetic rings, as obtained by a legitimate process of inference, we find a symmetry of disposition that is striking and suggestive. From Neptune to Jupiter we find a progressive increase in thickness that is entirely in con- formity with the nebular hypothesis. From the asteroids to Mercury there is a similar progressive increase which is similarly in entire harmony with the hypothesis. And in the only group of satellites concerning which we have adequate data, there is observed a parallel phenomenon. But in the solar system there is a conspicuous break in the uniformity of succession ;. and this break curiously occurs just at the place where, according to the most plausible supposition, there was an arrest or failure in the normal formation of a planet. I have partially succeeded in tracing this arrest or failure to the immediate effects wrought by the mere proximity and gigantic size of the planet just preceding in the order of detachment. Whether it can be shown that this cause, which well-nigh accounts for one of this group of phenomena, will account in some analogous way for the whole group ; whether it can be shown that the detachment of this gigantic mass may have altered the dynamic relations ^ That is, in December, 1870, 374 COSMIC PHILOSOPHY. [ft. ii. of the central splieroid in such a way as to reduce to a minimum its power of eliminating further rings ; I will not pretend to say. It seems to me better to leave the problem with this clear and definite statement, rather than to encumber it with hypothetical explanations which are quite likely to prove purely gratuitous. Of the various ex- planations which have occurred to me, none seem at all satisfactory ; and I will gladly resign, into abler hands, the task of solving the problem. What we may regard, how- ever, as fairly established, is this : that while, after the formation of Jupiter, the detachment of rings followed the same law of progression as before, there was nevertheless some newly-introduced circumstance present which affected the whole series of detachments in common. But while the non-explanation of this newly-introduced circumstance leaves a serious gap in the argument, it is to be noted that all the facts, so far as collated, are in harmony with the nebular hypothesis, — the existence of the zone of asteroids, in par- ticular, furnishing powerful evidence in its favour. If we pass from this complicated problem to the much simpler one of the distribution of the satellites, we shall find evidence in behalf of nebular genesis so remarkable as almost to amount to demonstration. Whoever has read the favourite speculations of theologians concerning the " plu- rality of worlds," will doubtless remember how strikingly the divine goodness is illustrated in the law that in general the remoter planets have the greater number of satellites. Here however, as in so many cases, observes Mr. Proctor, " the scheme of the Creator is not so obvious to human reasoning as some have complacently supposed." The " contrivances " for lighting Saturn are by no means what they ought to be, according to this teleological hypothesis. The illuminating power of our moon is (from its greater proximity to the sun) sixteen times greater than that of all the eight moons of Saturn combined ; while if that planet were habitable, his CH. v.] PLANETARY EVOLUTION. 375 rings would prove a formidable nuisance. Mr. Proctor has shown that, in latitudes corresponding to that of New York and Naples, they cause total eclipses of the sun, which last seven terrestrial years at a time. But the problem which natural theology thus fails to solve, is completely solved by a very simple mechanical consideration. Since the detach- ment of a moon-forming ring from a contracting planet depends on the excess of centrifugal force over gravity at its equator, it is evident that rings will be detached in greatest numbers from those planets in which the centrifugal force bears the highest ratio to gravitation. Such planets will have the greatest number of moons. And such, in fact, is the case. Of the four inner planets, which rotate slowly, and in which the centrifugal force is therefore small, only the earth is known to have a satellite.^ But Jupiter, whose centrifugal force is twenty times greater than that of any of the inner planets, has four satellites. Uranus, with still greater cen- trifugal force, has at least four, and probably six or eight moons. And finally Saturn, in which the centrifugal force is one-sixth of gravity, being nearly fifty times greater than on the earth, has at least eight moons, besides his three unbroken (or partly-broken) rings. Mr. Spencer may well declare that this emphatic agreement of observation with deduction is an imanswerable argument in favour of the nebular theory. Here, where the dynamic relations involved are so simple that we have no difficulty in tracing them, the significance of the result is unmistakeable. Where we are enabled thus directly to put the question to Nature, there is no ambiguity in her answer. In the quoit-shaped rings which girdle Saturn, we have a curious vestige — upon the significance of which Kant strongly insisted — of the ancient history of our planetary 1 It is not improbable that Venus may have a satellite also. Several astro- nomers have declared that they have seen such a satellite ; but as their testi- mony seems difficult to reconcile with that of other astronomers, equally competent as observers, the question must remain an open one for the pii'scnt. 378 COSMIC PHILOSOPHY. [ft. ii. on the earth. The trade-winds, due to the swift rotation of the planet, gather these enormous masses into belts parallel with its equator. Storms and typhoons are incessantly raging in this vapour-laden atmosphere; and the forces at work there are so stupendous that dense cloud-belts, thousands of miles in width, are often formed in a single hour. This state of things is not like that which is now witnessed upon the earth's surface ; it is more like the state of things observed upon the sun, where tornadoes continually occur, in which the earth, if it were there, would be whirled along like a leaf in an equinoctial gale. A similar state of things must have existed, in miniature, upon our own planet, in that primitive age when its oceans were in large part held suspended in the dense seething atmosphere, and when the intense volcanic fires within kept the surface in ceaseless agitation. In Saturn similar phenomena are witnessed. The appearance called the " square-shouldered figure " of Saturn, first observed by Sir William Herschel in 1805, has suggested the conclusion that the giant bulk of the planet "is subject to throes of so tremendous a nature as to upheave whole zones of his surface five or six hundred miles above their ordinary level." Whether this be really the case, or whether, as Mr. Proctor more plausibly suggests, the prominences which give the square-shouldered aspect are due to the shoving up of immense masses of cloud far above the mean layer of Saturn's cloud-envelope, we must equally recognize the presence of intense heat and furious volcanic action in the interior of that planet. When we add that recent calculations have made it almost certain that both Jupiter and Saturn are to some extent self-luminous, it becomes probable that these great planets still resemble their parent, the sun, more closely than they resemble their younger and smaller brethren. Very different is the state of things witnessed upon the moon. The absence of an atmosphere from the lunar surface was long since proved by the fact that " when stars are CH. v.] PLANET AEr EVOLUTION. 379 occulted by the moon, they disappear instantaneously," — which would not be the case had the moon an appreciable atmosphere; and spectroscopic evidence has confirmed this conclusion. ISTor are there any signs of the presence of liquid oceans, or of running water. Yet if the moon was originally formed from an equatorial zone of the earth, it would seem that it ought to contain the same materials which have from the oldest times constituted a considerable part of the terrestrial surface. Besides this, the vast plains on the moon which the old astronomers supposed to be seas, and named as such, are now held to be areas underlaid by sedimentary rocks implying the former presence of water.^ If this view be correct, there must in all probability have been winds to excite the erosive movements of the water which caused this sedimentation. For tidal action upon the moon cannot be regarded as a considerable factor in the erosion, unless we go back to that enormously remote period when the earth's tidal pull was stiU employed in dragging the moon's rotation into synchrony with its revolution. Here there is an apparent discrepancy, which will dis- appear, however, when we inquire further into the past career of the moon as indicated by the present condition of its surface. To a great extent the lunar surface is made up of huge masses of igneous rock, through which at short intervals yawn enormous volcanic craters, whose fires seem to be totally extinguished. The giant forces required to bring about such a state of things are now quiescent. And this implies that the moon is a dead planet. It implies that the thermal energies which were once instrumental in raising those huge cones, Tycho, Copernicus, and the rest — quaintly named after our terrestrial heroes of science — and which once drove up fiery streams of molten lava through their ample ^ Moreover, " it is uot to be forgotten that, so far as terrestrial experience is concerned, water is absolutely essential to the occurrence of volcanic action." Proctor, The Moon, p. 353. 382 COSMIC PHILOSOPHY. [ft. u driven back towards the surface. In this way there is kept up a circulation of water through the peripheral portions of the earth's crust. But as the earth becomes cooler and cooler, the water wUl be enabled to circulate at greater and greater depths, thus materially lowering the level of the ocean. In this way, long before the centre has become cool, all the surface-water of the earth will have been sucked into the pores of the rocks, and a similar process will afterwards take place with the atmosphere. M. Saemann shows that by the time the earth had reached complete refrigeration, the pores of the rocks would absorb more than one hundred times the amount of all the oceans on the globe, while room woiild still be left for the retiring atmosphere. Now this state of things, which wiU no doubt by and by be realized on the earth, would seem to be already realized on the moon. Being forty-nine times smaller than the earth, the moon has cooled with great rapidity, and its geologic epochs have been correspondingly short.^ After the moon, we are more familiar with the surface of Mars than with that of any other heavenly body, the posi- tion of Venus being very unfavourable for thorough observa- tions. Concerning the physical geography and meteorology of Mars, some trustworthy information has been obtained. The distribution of land and sea over his surface is sufficiently obvious to be delineated in maps. He possesses liquid oceans, proved by spectroscopic evidence to consist of water, and his atmosphere is gaseous. That he possesses climates analog- ous to our own might be inferred from the inclination of his axis to his orbit-plane, and is inductively proved by the fact that we can actually see his polar snows accumulate during the Martial winter and melt away at the approach of the ' It should be added that the rapid cooling of the moon would greatly increase the porosity of its substance. Prof Frankland has shown that " assuming the solid mass of the moon to contract on cooling at the same rate as granite, its refrigeration through only 180° F. would create cellular space equal to nearly fourteen and a half millions of cubic miles." CH. v.] PLANETARY EVOLUTION. 383 Martial summer. Coincidences like these bear sufficient testimony to a general resemblance between Mars and the earth. For ■where there are oceans and clouds and an atmosphere and polar snows, there must also be currents, aerial and oceanic, as well as rains, rivers, and sedimentary rocks ; so that the surface of Mars must probably present geologic phenomena not essentially ^inlike those witnessed upon the earth. Whether such geologic similarity has entailed a further resemblance in the case of organic and super-organic phenomena, must be left for the more profound deductive science of some future day to determine. Thus from whatever point of view we study our planetary system, we find such a congeries of phenomena as would have been produced by the gradual development of the system from a homogeneous nebula. On summing up the conspicuous facts already cited, we see that the nebular hypo- thesis fully explains the shapes of the planetary orbits, and their slight inclinations to the plane of the solar equator ; the shapes of the satellite-orbits, and their proximate coincidence with the equatorial planes of their primaries ; the inclina- tions of the planetary axes to their orbit-planes ; the oblate figures of the planets ; their velocities of rotation ; the direc- tions in which they revolve ; and the directions in which they rotate. To this last clause the apparent obstacle pre- sented by the retrograde rotation of Uranus (and possibly of Neptune also) is seen on closer examination to be no real obstacle ; and the fact that the exception occurs among the outermost planets, just where we might expect it to occur, if at aU, is a powerful argument in favour of the general theory. A like powerful argument is furnished by the existence of apparently-continuous rings about Saturn, the planet upon which the centrifugal force bears the highest ratio to gravity. Still more convincing is the testimony rendered by the dis- tribution of satellites, — a testimony well-nigh meeting all the requirements of crucial proof Irregular as are the sizes 384 COSMIC PIULOSOFHY. [pt. ii. of the planets on a superficial view, we find beneath this apparent irregularity a marvellous symmetry of disposition, the explanation of which, though incomplete, is as, far as it goes in favour of the nebular hypothesis. The breaking up of the zone of asteroids, though not fully explained, is seen to have occurred in the only part of the system where such an event, according to the hypothesis, was likely to occur. And finally the geologic or meteorologic phenomena manifested by the four planets whose surfaces have thus far been success- fully studied, are just what the theory requires them to be. The intense heat and furious volcanic activity of Jupiter and Saturn, the extreme loss of heat and cessation of volcanic activity upon the moon, the moderate temperature and habit- able aspect of Mars, are alike deducible from the nebular hypothesis. I doubt if such persistent agreement between deduction and observation has ever been witnessed in the case of an erroneous or radically inadequate hypothesis. If the sole ultimate test of a theory is that it reconciles the order of conceptions with the order of phenomena, may we not say that the theory of Kant and Laplace, having sustained the repeated application of this test, may be accepted provisionally as a true account of the past history of our system of worlds ? It is true that the application of the test has not yet been made exhaustive ; the verification is not yet complete. Some of the interpretations above given are still, as I have acknowledged, but partial ; and there are yet other groups of phenomena with which I have not ventured to meddle. To the various densities of the planets I have alluded but incidentally ; and the various angular velocities, as well as the order of distances formulated in the law of Titius, still await an explanation. Besides which, the evi- dence from the physical condition of the surfaces of Mercury and Venus, Uranus and Neptune, and the moons of the four outer planets, is not yet forthcoming. It would be asserting CH. v.] PLANETARY EVOLUTION. 38S too much, therefore, to assert that the nebular hypothesis is completely verified, like the hypothesis of gravitation. But on the other hand, they understand little of the logic of scientific inquiry who expect to obtain the same kind and degree of evidence in the former case as in the latter. It was part of Newton's rare good fortune that his hypothesis was the generalization of a physical property of matter, which could be verified by a single crucial instance. In none of the concrete sciences can such kind of verification be looked for. A theory relating to a heterogeneous assem- blage of concrete phenomena cau only be verified graduallj', as the successive groups of phenomena in question are one after another successfully studied and interpreted. Thus the complete verification of the nebular hypothesis, as applied merely to the solar system, involves the complete explana- tion of the chief dynamic and physical features of the system ; and for this we have yet to wait. Meanwhile the theory possesses such unmistakeable marks of genuineness, it conforms in so many and various ways to the test of reconciling the order of conceptions with the order of phenomena, that no one capable of estimating scientific evi- dence would hesitate in provisionally accepting it. Devised to account for a certain limited group of phenomena, it not only accounts for these, but also for other groups of pheno- mena, not considered by its propounders. Eacts which on a superficial view appeared as obstacles to the theory, have on closer examination turned out to be powerful arguments in its favour. It is sustained by all the facts within our ken, and invalidated by none. And it has so far thriven with the progress of discovery during the past hundred and twenty years, that at the present moment it commands wider assent than at any previous time since its first promulgation. Of this last statement we find striking confirmation as we pass beyond the limits of the solar system and seek for evidence in the remotest depths of stellar space. It is well VOL. I. c c 386 COSMIC PHILOSOPHY. [ft. ii. known that Sir William Herschel supposed certain irresolv- able nebiilee to consist of self-luminous vapour hovering cloud-like in space. Laplace associated this hypothesis with his own theory of planetary evolution ; pointing to the pre- sent existence of nebulous masses as confirmatory proof of the past existence of such a nebulous mass as his theo;ry required. According to this view, the irresolvable nebulae are simply starry systems in embryo ; and when our planetary system consisted simply of the sun diffused in gaseous form over a circumference of perhaps thirty thousand million miles, it was just like one of these nebulse. But since Herschel's time many nebulae, which he regarded as irresolvable, have been resolved into dense starry clusters. The great nebula in Orion, upon which Herschel placed great reliance, was resolved both by Lord Eosse's reflector and by our Harvard refractor ; and the suspicion began accordingly to arise that, if our telescopes were only powerful enough, there might prove to be no irresolvable nebulae at all. Hence many writers thoughtlessly hastened to proclaim that the nebular theory had lost its chief support, forgetting that the over- whelming evidence furnished by the comparatively well- known structure of the solar system must take precedence of any hypothesis as to the character of remote and less-known sidereal phenomena. Mr. Chambers, in giving an account of the resolution of the " dumb-bell " nebula in Vulpecula, rather gleefully wrote the obituary of the nebular hypothesis ; but like many other obituaries, this one turned out to be premature. For now came Mr. Huggins, with his spectro- scope, and proved once for all that the wary and sagacious Herschel, who hardly ever made a false step, was right, here as elsewhere. In 1864 Mr. Huggins analyzed the light sent from a nebula in Draco, and found it to contain the bright lines which are sure evidence of the gaseous .condition of the luminous body. Since then several other nebulae have been proved to be gaseous ; so that the question may now be cH v.] PL A NET A RY E VOL UTION. 387 regarded as settled for ever, and as settled in favour of the nebular hypothesis. Henceforth, to the evidence found in the structure of our planetary system, there may be added the weighty argument that masses of matter still exist in space, in the very condition in which our system must have originally existed. If the nebular hypothesis was ever to be subjected to a hazardous trial, one would suppose that the discovery of spectrum analysis must have furnished the occasion. Here is a discovery which has suddenly enlarged our knowledge of the stellar universe in a manner utterly beyond the power of the greatest and subtlest mind to have predicted twenty years ago, — a discovery which not only reveals to us the actual motions of the stars, but even penetrates into their molecular structure, and discloses the chemical elements of which their surfaces are composed as well as the physical state of aggregation of those surfaces. Now if ever, one might think, is the time to find out whether oar nebular hypothesis, devised in an era of comparatively scanty astro- nomical knowledge, is a sound liypothesis or not. If it survives this immense, unprecedented extension of our know- ledge, what more magnificent triumph could we wish for it ? And here we see that the very first result of the application of spectrum analysis to sidereal phenomena has been the placing of the nebular hypothesis upon a firmer basis than ever before, removing the only serious obstacle which had hitherto deterred many cautious thinkers from committing themselves to it. Spectroscopic researches but lately undertaken, and not yet carried out to a decisive result, seem likely not only further to strengthen the noble theory of Kant and Laplace, but to give it a comprehensive significance of which those great thinkers could never have dreamed. Along with further confirmation of the process of mechanical and physical evolution, as originally formulated in their hypothesis, evi- c c 2 38S! COSMIC PIJILOSOPHY. [pt. ii. dences are daily coming in to sliow that there is going on a parallel XDrocess of chemical evolution from homogeneity to heterogeneity, which is no less wonderful in its significance. The old enipiiical classification of stars according to their colours is beginning to have a new meaning. The method of comparison is becoming applicable in astronomy, as it has long been employed in the study of organisms, of societies, and of languages. It begins to be probable that among the various groups of stellar bodies there may be found cosmical matter in many different stages of evolution, — from the pri- mitive nebula which yields but a simple hydrogen-line, to such a highly-evolved body as our own sun with the many- lined vapour of iron abundant in its heated atmosphere. But into this fascinating region of speculation ib would be somewhat premature , for us now to enter. Merely indicating what a rich harvest of discovery is here likely to reward the labourers of the immediate future, T would call attention to an interesting speculation of Mr. Spencer's, the possible inadequacy of which need not weaken the effect of the evidence above cited from planetary phe^ nomena, and which is in every way worthy of serious consideration. According to Mr. Spencer, the distribution of nebulae affords a significant illustration of the nebular hypothesis. Speaking generally, nebulse occur in regions where developed stars are scarce. The vast groups of spherical nebulee, here and there partly developed into starry clusters, which con- stitute the so-called Magellanic Clouds, are situated in a district of the sky that is otherwise starless. Now by far the most striking of this class of facts is offe which serves to bring the entire sidereal system into direct comparison with that little portion of it to which we belong. Just as the planets lie almost entirely in a single plane, so the stars are distributed in almost infinite numbers in the plane of the Milky Way, while elsewhere they occur rarely. And just CH. V.J PLANETARY EVOLUTION. 389 as the comets are chiefly distributed aboiit the poles of our solar system, their orbits cutting its equatorial plane at great angles, so the nebulae are found in greatest numbers about the poles of the galaxy. It seems unlikely that this parallelism, which Mr. Spencer was the first to point out, should be accidental. It indicates a common mode of evo- lution of the whole starry system. It vaguely points to a gigantic process of concentration going on throughout the galaxy, analogous to the local process of concentration which has gone on in our own little planetary group. Still more obvious will this become when we consider the explanation of these phenomena which Mr. Spencer has offered. Observation shows that while the more consolidated nebulse are oval or spheroidal in shape, the less consolidated nebulae are often extremely irregular, throwing outdong arms of vaporous matter into the adjacent spaces. This agrees with what we have learned to expect in any rotating mass which gravitation is slowly drawing closer and closer together. The oval form is due, as we have seen, to the combined effects of gravitation and rotatory movement. But this im- plies an earlier state in which the figure was irregular. ISTow while the heavier portions of the mass were being drawn together so- as to acquire a spheroidal contour, the lighter portions, floating farther from the centre of gravity, would remain like detached shreds of cloud, or like long luminous streaks. And while all these would ultimately be compelled by gravitation to revolve about the centre of the mass, never- theless the lightest and outermost shreds would be a long time in acquiring a definite direction of revolution. While the greater number would be doubtless drawn in and ab- sorbed by the ma;in mass at an early stage, the chances are that some would not arrive until the main mass had become considerably contracted. N"ow it is easy to see that such late arriving flocculi, coming toward the centre of gravity from a great distance, and therefore having small angixlar 390 COSMIC PHILOSOPHY. [pt. ii. velocities, will move in very eccentric ellipses. In the next place, while they will come from all parts of the space which the mass originally occupied, they will come chiefly from regions remote from the plane in which integration has been most marked, — that is, from the poles of the nebula rather than from its equatorial regions. And thirdly, having failed to accompany the retreating mass of the nebula while it was first acquiring a definite direction of rotation, their own revolutions will be determined chiefly by their irre- gular shapes, and they will be as likely to be retrograde as direct. All this is true of comets : they come chiefly from high solar latitudes, along immensely eccentric orbits, and in directions which are indifferently direct or retrograde. And when we add that they are nebulous in constitution, it appears highly probable that they are simply outlying shreds of the nebula from which our planetary system ^has been developed. As for the irresolvable patches of nebulous matter which are distributed about the poles of the galactic circle, their distance from us is so great that we have not yet ascertained anything trustworthy concerning their motions. But the fact that their position in high galactic latitudes is explicable upon the same general principles which explain the positions of comets, raises a presumption that their relation to the galaxy as a whole may somewhat resemble that which comets bear to the solar system. Between the possible careers of the nebulae and the comets, there is, however, a mighty difference. The nebula which we see through quadrillions of miles shining by a light of its own must needs be an enormous object — enormous in mass as well as in volume — and its gravitative force must be pro- portionate to its size. While, therefore, its gradual con- traction is likely to be attended by its development into a planetary system, by a process of integration and diffe- rentiation such as we have, here described ; on the other- CH. v.] PLANETARY EVOLUTION. 391 hand the comet is an object of inconsiderable mass^ though often of considerable volume. The slight concentration of which it is capable will not produce planetary systems ot even asteroids, but only streams of meteors or shooting-stars, such as are now poured down upon the earth and its neigh- bour planets at the rate of a hundred thousand million each year. The researches of the past ten years have gone far to show that such meteoric streams differ from nebulous comets in no respect save in their greater aggregation ; the difference being similar to the difference between a cloud and a shower of rain-drops. We are constantly encounter- ing portions of these condensed comets and uniting them with our own planetary substance. And in this way the integration of the outlying portions of our primitive nebula is, at this late day, still going on. As we pause to survey, in a single comprehensive glance, this gigantic process of Planetary Evolution, in which the integration of matter and concomitant dissipation of mole- cular motion, kept up during untold millions of ages, has brought about the gradual transformation of a relatively homogeneous, indefinite, and incoherent mass of nebular vapour into a decidedly heterogeneous, definite, and coherent system of worlds ; we are at first struck by the peculiarity that the process has apparently long since come to a close in the establishment of a complete moving equilibrium. Habituated as we are to the contemplation of fleeting phenomena, the stars in their courses have become the types of permanence; and the stability of our planetary system has furnished a fruitful theme for the admiring com- ments of the mathematician and the theologian. In so far as this appearance of eternal stability is well founded, it admirably illustrates the theorem, already cited in our dis- cussion of the rhythm of motion, that wherever the forces in action are few in number and simple in composition, the 392 COSMIC PHILOSOPHY. [pt. h.- resulting rhythms will be simple and long-enduring. ISTever- theless the processes stiU going on in our system are such as to forbid the conclusion that this apparently permanent equiliblrium is destined really to be permanent. The con- centration of matter and concomitant dissipation of mole- cular motion, which has gone on from the beginning, must still continue to go on untO. it has reached its limit. That consolidation and accompanying refrigeration which has changed the earth from a nebula into an incandescent star, and from a star into an inhabitable planet, must continue until a state of things is inaugurated for which we must seek a parallel in the present condition of the moon. So, too, the contraction which generates the prodigious quantity of heat daily lost by the sun, cannot go on forever without reducing the sun to a solidity incompatible with the further generation of radiant energy. Thus the moon appears to afford an example of the universal death which in an unimaginably remote future, awaits all the members of the solar system. It then be- comes an interesting question whether this cosmic death will be succeeded by Dissolution, — that is, by the rediffu- sion of the matter of which the system is composed, and by the reabsorption of the lost motion or its equivalent. We shall find it difiScult to escape the conclusion that such a Dissolution must ultimately take place. If, along with the dissipation of molecular motion already described, the planets are also losing that molar motion to which is due their tangential momentum, this loss of motion must ultimately bring about their reunion with the sun. Upon such a point direct observation can help us but little ; but there are two opposing considerations, of a force which none will deny, and based on facts which none can dispute. Two sets of circumstances are struggling for the mastery, — the one set tending to drive the planets farther and farther away from the centre of the system, the other set tending to CH. v.] PLANETARY EVOLUTION. 393 draw them towards the centre. Let us see whieh set must prevail in the end. Hitherto, in all probability, the first set of circumstances has had the advantage. There is little reason to doubt that all the planetary orbits, both primary and secondary, are somewhat larger'now than they were originally. This is an indirect consequence of the slow loss of rotatory momentum due to tidal action. The calculation by which Laplace thought he had proved that the terrestrial day had no-t lengthened since the time of Hipparchos, has been shown by. Prof. Adams to be vitiated by the inclusion of an er- roneous datum; and the theory involved is no longer tenable. It has been proved that the tidal wave which the moon draws twice a day around the earth, in the op- posite direction to the terrestrial rotation, acts upon the earth like a brake on a carriage-wheel. Owing to this cir- cumstance, the day is now one eighty-fourth part of a second longer than at the beginning of the Christian era ; and it i» destined to continue lengthening until in the remote future there will be from three to four hundred hours between sunrise and sunset. But the rotatory momentum thus lost by the earth is not destroyed. In conformity with a well-known principle of dynamics, it is added to the tangential momentum of the moon, and thus lengthens the radius of the moon's orbit. The more slowly our planet rotates, the farther the moon retires from us. A similar relation holds good in the case of the planets and the sunv Not only is it demonstrable d priori that the planets must cause tides upon the surface of the sun, but the tides caused by all the primary planets, save Mars, Uranus, and ISTeptune, have been actually detected by a minute comparison of the variations in the solar spots. These tidal waves are drawn around the sun in the direction opposite to that of his rotation, and must therefore exert a retarding effect. And the rotatory momentum thus stolen from the sun ia 394 COSMIC PHILOSOPHY. [pt, ii. added, in accordance with a pro raid principle of distribu- tion, to the tangential momenta of the various planets concerned in the theft. There can be little doubt, there- fore, that all the planetary orbits, both primary and second- ary, are steadily enlarging, and that this process must go on until that synchrony between revolution and rotation now witnessed in our moon becomes universal, unless it is pre- viously checked by the cessation of tidal phenomena. As between the earth and moon, for example, the ultimate result of the whole process must be the lengthening of the terrestrial day until it corresponds with a lunar month, so that the earth and moon will move in relation to each other just as if joined together by a rigid rod. This result will actually be realized unless forestalled by the completed refrigeration of the earth, which will put an end to the tidal friction. In like manner the sun's rotation must diminish until equilibrated with the motions of the planets, unless this result is forestaUe'd by the completed refrigera- tion of the sun. And in all cases, so long as the process goes on, there must be a tendency, however slight, for the planets to recede from the sun. The action of this set of circumstances, however, though hitherto no doubt predominant, is strictly limited in duration. Sooner or later an equilibration of motions will be reached, and this receding tendency will cease to be manifested. It is quite otherwise with the opposing set of circumstances which we have now to consider. We have now to contem- plate a cause which operating from the very outset, and still insidiously operating, will continue to operate long after the process just described has come to an end. Each year's dis- coveries show more and more conclusively that the inter- planetary spaces are filled with matter. The existence of some interplanetary and interstellar matter is iodeed a necessary condition for the transmission of light and other forms of radiance. Now Avherever a body moves through a CH. v.] PLANETARY EVOLUTION. 395 material medium, it meets with resistance ; it imparts motion to the medium, and loses motion in so doing. If the body is a planet like Jupiter, weighing a couple of septillions of tons, and rushing along at the rate of eight miles per second through an ether far lighter than the air left in an exhausted receiver, the resistance will be inconceivably small, I admit. Still there will be resistance, and long before the end of time, this resistance will have eaten up all the immense momen- tum of the planet. A Hindu, wishing to give expression to his idea of the duration of hell-fire, said that if a gauze veil were to be brushed against the Himalaya mountains once in a hundred million centuries, the time required for thus wear- ing away the whole rocky range would measure the torments of the wicked. One marvels at siich a grandiose imagination ; but the realities of science beggar all such attempts at giving tangible shape to infinitude. The resistance of an ethereal medium may work its effects even more slowly than the Hindu's veil, yet in time the effects must surely be wrought. Either the planets are moving in an absolute vacuum — a supposition which is incompatible with the transmission of heat and light — or else the resistance of the medium must tend to diminish their angular velocities.^ In the absence of any counteracting agencies — and, after the cessation of the process above described, none such are assignable — this loss of tangential momentum must ulti- mately bring all the planets into the sun, one after another, beginning with Mercury and ending with Neptune. Here the concentration of matter appears to have reached its limit. But what must now happen ? Let us note that the tangential momentum lost by the planet is lost only relatively to its distance from the sun. As the planet draws nearer to the sun, its lost tangential momentum is replaced, and somewhat more than replaced, by the added velocity due to the increased gravitative force ' See Balfour Stewart, The Conservation of Energy, p. 96. 396 COSMIC PHILOSOPHY. [pt. ii. exerted by the sttii at the shorter distance. But this newly- added momentum is all needed to maintain the planet at its new distance from the central mass, and can never be avail- able to carry it back to the aid distance. It is thus that Eneke's comet moves more and more rapidly as it approaches the sun, into which it appears t& be soon destined to be drawn. For these reasons the earth, which now moves at the rate of 18 miles per second, would attain a velocity of 379 miles per second when in the immediate neighbourhood of the solar mass. Hence when at last the planet strikes the sun, it must strike it with tremendous force. In a col- lision of this sort, the heat generated by the earth and sun alone would suffice to produce a temperature of nearly nine million degrees Fahrenheit. Without pursuing the argument into further detail, it is obvious that the integration of the whole solar system, after this fashion, would ber followed by the complete disintegration of the matter of which it is con- stituted. After the reunion of the planets with the sun, the next stage is the dissipation of the whole mass into a nebula. If we now go back for a moment to the beginning, and ask what antecedent form of energy could have generated the motion of repulsion which sustained our genetic nebula at its primitive state of expansion, the reply must be that nothing but a rapid evolution of heat could have generated such a motion of repulsion. And if we ask whence came this rapid evolution- of heat, we may now fairly surmise that it was due to some previous collision of cosmical bodies ; arrested molar motion being incomparably the most prolific known source of heat. Thus we get a glimpse of some pre- ceding epoch of planetary evolution, from the final catastrophe of which emerged the state of things which we now witness. We have here reached the very limit of scientific inference. For note that, since the greater part of the potential energy represented by the primitive expansion of our solar nebula CH. v.] PLANETARY EVOLUTION.. 397 has been trausformed into heat and radiated away, and is not represented by any form of motor energy now stored up in the solar system, it follows that the sudden transformation of the penultimate molar motions of the planets into heat cannot result in the production of another nebula so large as the one from which our present system has been evolved. In seeking to trace out tlie implications of this conclusion, we at once arrive at an impassable barrier, which is only shifted, but not overthrown, when we consider the .results of the probable ultimate conflict between our own system, thus dis- integrated, and other sidereal systems belonging to our galaxy. In order to give a complete account of the matter, we ought to know what has become of all this motor energy whfch we have been so prodigally pouring away, in the shape of radiant heat, into the interstellar spaces. Is the equivalent of this motor energy ever to be restored, or is tlie greater part of it forever lost in the abysses of iuifinite space ? Eefore we can answer suclr a question, we need to know whether the inter- stellar ether, which is the vehicle for the transmission of molecular motion, is definitely limited in extent, or prac- tically infinite ; and we need to take into the account the dynamic relations, not only of our entire galactic system, but of other stellar systems, if such there are, beyond the utmost ken of the telescope. Here science fails us. Astro- nomy, the simplest and clearest of the sciences, becomes, when treated on this great scale, the most difficult and obscure. An infinity and an eternity confront us, the secrets of which we may not hope to unravel. At the outermost verge to which scientific methods can guide us, we can only catch a vague glimpse of a stupendous rhythmical alterna- tion between eras of Evolution and eras of Dissolution, suc- ceeding each other " without vestiges of a beginning and without prospect of an end." CHAPTEE VI. THE EVOLUTION OP THE EAETH. In treating of Evolution in general, it was shown how organic bodies are, by a peculiar concurrence of conditions, enabled to lock up a great deal of motion within a small compass, so that permanent redistributions of structure and function can be effected. From the decisiveness with which this peculiar advantage possessed by organic bodies was indicated, it might have been surmised that in the case of inorganic aggregates an attempt to trace the secondary phenomena of differentiation and integration would prove illusory, owing to the absence of this concurrence of con- ditions. In many inorganic bodies it is true that there does not go on to any n-otable extent that secondary redistribution which results in increase of heterogeneity. The evolution of a cloud, a rock, or a crystal, is little more than an integration of matter attended by dissipation of motion. In the evolu- tion of the solar system, on the other hand, we have witnessed an increase in heterogeneity, definiteness, and coherence that is very marked, though by no means so prominent as in the case of organic evolution. This increase in determinate multiformity, such as it is, is due to the special mechanical principle that in any rotating system of particles, regarded as practically isolated, a steady concentra- CH. VI.] THE EFOLUTION OF THE EARTH. 399 tion, entailing increased rotatory velocity, must end in the segregation of the equatorial zone from the rest of the system. This principle is exemplified, on a diminutive scale, in the artificial evolution of a system of oil-globules, whereby M. Plateau has imitated the evolution of the planets. To the resulting equilibration between gravity and the centrifugal tendency at the place where the detachment occurred, is due the permanence and definiteness of the structural different- iation. Owing to these conditions, and to its enormous size, implying great power of condensation along with the very slow dissipation of the heat generated by the condensation, the integration of our genetic nebula has been compatible with the retention of much relative motion of parts. And here accordingly, as in all cases where there is a considerable retention of internal motion, the secondary rearrangements characteristic of Evolution have been conspicuously mani- fested. In the evolution of our earth, regarded by itself, we have also to notice a very decided progress in determinate multiformity, even without taking into the account that specialized group of terrestrial phenomena which we distinguish as organic. Here there have been two conditions favourable to the retention of enough motion to allow considerable secondary rearrangement of parts. In the first place, the great size of the earth has prevented it from parting too rapidly with the heat generated during its condensation ; and since the early formation of a solid, poorly-conducting crust, the loss from radiation would seem to have been very gradual. The importance of this circumstance may best be appreciated by remembering the very different career of the moon, as indicated in the foregoing chapter. The disappearance of igneous and aqueous agencies on the moon implies the cessation of structural rearrangement there at this early date;^ and when we sought for an explana- ' 1 This statement must be taken, however, with some qualification. See above, p. 380. 400 COSMIC PIIILOSOPHY. [pt. ii. tion of this state of things, we found an adequate explanation in the rapid loss of heat which the small size of the moon has entailed. It is not likel)^ therefore, that the moon can ever have been the theatre of a geologic and organic develop- ment so rich and varied as tliat which the earth has witnessed.^ In the second place, the following chapter will show that the chief circumstance which has favoured terrestrial hetero- geneity has been the continuous supply of molecular motion from the sun. To this source may be traced aU the aqueous phenomena, save the tides, which concur in maintaining the diversity of the earth's surface. And having thus seen how a complex geologic evolution is rendered possible, w« shall further discern that organic evolution also — that highly specialized series of terrestrial events — is rendered possible by the same favouring circumstance. ■ An example of the too hasty kind of inference which is often drawn in discnssing the question of life upon other planets, may be found in a recent lucid and suggestive pamphlet by Prof. Winchell, entitled " The Geology of the Stars." "The zoic age of the moon," says the author, "was reached while yet our world remained, perhaps, in a glowing condition. Its human period was passing while the eozobu was solitary occupant of our primeval ■ocean." More careful reflection will probably convince us that, with such a rapid succession of geologic epochs, the moon can hardly have Irad any human period. For the purposes of comparative geology, the earth and the moon may be regarded as of practically the same antiquity. Now, supposing the earliest ape-like men to have made their appearance on the earth, say during the Miocene epoch, we must remember that at that period the moon must have advanced in refrigeration much farther than the earth. Supposing organic evolution to have gone on with equal pace in the two planets, it might be argued that the moon would be fast becoming unfit for the support of organic life at about the time when man appeared on the earth. Still more, it is a fair inference from tbe theory of natural selection, that upon a small planet there is likely to be a slower and less rich and varied evolution of life than upon a large planet. On the whole, therefore, it does not seem likely that the moon can ever have given ripe to organisms nearly so high in the scale of life as human beings. Long before it could have attained to any such point, its surface is likely to have become uninhabitable by air-breathing organisms. Long before this, no doubt, its surface air and water must have sunk into its interior, and left it the mere lifeless ember that it is. The moon would thus appear to be not merely an extinct world, but a partially aborted world ; and tlie still smaller asteroids are perhaps totally aborted worlds. Nevertheless, from the earth down to the moon, and from the moon down to an asteroid, the differences are at bottom only differences of degree ; though the differences in result may range all the way from a world habitable by civilized men down to a mere dead ball of planetary matter. An interesting example, if it be sound, of the continuity of cosniical phenomena. CH. VI.] THE EVOLUTION OP THE EARTH. 401 Let us now proceed to note two or three conspicuous features of geologic evolution, remembering that in so doing we are but following out a portion of the phenomena of planetary evolu- tion discussed in the preceding chapter. There is no demar- cation in the series of phenomena, save that which we arbitrarily introduce for convenience of study and exposition. The process of integration of matter and dissipation of motion which we have just witnessed in the solar nebala as a whole, we have now to witness in that segregated portion of it which we call our earth, and we have to observe how here also in- determinate uniformity has been succeeded by determinate multiformity. In the formation of a solid crust about the earth, there appeared the first conspicuous geologic differentiation; re- sulting not only in increased heterogeneity, but in increased definiteness, as the crust gradually solidified. For not only did the planet thus acquire a more definite figure, but also a more definite movement ; since the solidification of the crust must have diminished the oblateness of the spheroid, thus gradually redTicing the disturbance known as precession. Next with the deposit of water in the hollow places of this crust, there came the differentiation between land, sea, and atmosphere ; and this differentiation became more marked as vast quantities of carbonic acid, precipitated in this primeval rain, left the atmosphere purer, and purified also the ocean by segregating its contained lime. At the same time that this vast condensation of ocean-water from pre-existing steam constituted a secondary integration. attendant upon the earth's loss of molecular motion, the further thickening of the solid crust began to entail other more local integrations. As Mr. Spencer points out, while the earth's crust was still very thin, there could be neither deep oceans nor lofty mountains nor extensive continents. Small islands, barren of life, washed by shallow lakes, void of animate existence, and covered with a dense atmosphere, loaded with carbonic acid and aqueous VOL. I. D D 402 COSMIC PHILOSOPHY. [ft. ii vapour, must have characterized the surface of our planet at this primeval epoch. But as the ever thickening crust slowly collapsed about its contracting contents, mountain ridges of considerable height could be gradually formed, islands could cohere over wider and wider spaces, and deeper basins would permit the accumulation of large bodies of water. Numerous integrations of islands into continents, and of lakes into oceans, would thus occur, making the differentiation of land and sea more distinct and definite. The integration of conti- nents and the rise of mountain chains in different directions must have enlarged the areas of denudation, and thus rendered possible the integration of masses of detritus into extensive sedimentary strata. Differences of watershed and river- drainage thus caused added variety to the resulting geologic formations ; and these, crumbling into soil of more or less richness, afterwards impressed differences upon vegetation, and thus indirectly upon animal life. Yet again, the thick- ening of the crust must have added to the definite hetero- geneity of the surface by its effect upon volcanic phenomena. While the crust was still thin, the angry waves of liquid matter imprisoned beneath must have continually burst through volcanic vents, suddenly vaporizing large quantities, of surface-water, and causing phenomena similar to those now witnessed upon Saturn and Jupiter. As the crust thick- ened, these volcanic agencies were more and more restrained: craters became restricted to certain localities where the crust was less thick than elsewhere, and earthquake waves began to run, as at present, along definite lines. Those well-regulated earthquake pulses which raise continents and ocean-floors at the rate of a few inches or feet per century, now began to in- crease the definite heterogeneity of the surface. To the long rhythms of elevation and subsidence thus produced have been due countless differentiations in the directions of ocean- currents and continent-axes, in watershed, in the composition of sedimentary strata, and in climate. And to all these may CH. VI.] THE EVOLUTION OF THE EAETH 403 be added the metamorphosis of sedimentary rocks by volcanic heat, and the seismic shoving up of strata at various angles. All these geologic phenomena are thus seen to be classifi- able as differentiations and integrations of the earth's superficial matter, caused by the continuous integration of the earth's mass with its attendant dissipation of molecular motion. We may next note that meteorologic phenomena are similarly classifiable. Before the solidification of its crust, our planet must have been comparatively homogeneous in temperature, owing to the circulation which is always maintained in masses of heated fluid. The surface-portions must, however, have been somewhat cooler than the interior, and this difference would be rendered more definite by the formation of the crust, and by the subsequent separation of the ocean from the gaseous atmosphere. As the contour of land and sea became more definite and more permanent, differences in temperature between different parts of the surface must likewise have become more decided. Neverthe- less the chief cause of climatic differentiations — the inclina- tion of the earth's axis— did not begin to produce its most conspicuous effects until a later period. As long as our planet retained a great proportion of its primitive heat, there could have been little difference between winter and summer, or between the temperature at the poles and at the equator. But when the earth had lost so much heat that its external temperature began to depend chiefly upon the supply of solar radiance, then there commenced a gradual differentia- tion of climates. There began to be a marked difference between summer and winter, and between arctic, temperate, and tropical zones. And now also the distribution of land and sea began to produce climatic effects, owing to the fact that solar radiance is both absorbed and given out more rapidly by land than by water. Areas of the earth's surface where sea predominated began now to be distinguished from areas where land predominated, by their more equable D D 2 404 COSMIC PHILOSOPHY. [ft. ii. temperature. And because the amount of solar radiance retained depends upon the density of the atmosphere, there ensued differences of climate between mountains and valleys, between table-lands and low-lying plains. Here too the increased heterogeneity was attended by increased definite- ness and permanence of climatic relations. For the thermal variations, depending on the earth's rhythmic change of position -with reference to the sun, set up atmospheric currents in definite directions and of tolerably regular recurrence. Sundry of these currents, swayed by the earth's rotatory momentum, became specialized as trade-winds and monsoons ; while in the ocean there went on a similar specialization, as exemplified in the constant course of the Gulf Stream and other marine currents. The definiteness of the total result, as well as its heterogeneity, may be well illustrated by any map of isothermal lines ; bearing in mind, as "we must, that during long periods these lines shift only within narrow limits. Among the various portions of our earth's surface, more- over, evolution has brought about a climatic interdependence. The dependence of terrestrial temperature upon the supply and distribution of solar radiance, has entailed a further dependence of local temperatures upon one another. For example the warm temperature of southern Europe is largely dependent on the hot dry winds which blow from Sahara, and which powerfully assist in melting the glaciers of the Alps. If Sahara were to be submerged — as indeed it has been at a recent epoch — these dry winds would be replaced by cooler winds charged with vapour, which would condense into snow on the Alps, and thus enlarge the glaciers already formed there, instead of melting them away. Thus the climate would be changed throughout Europe, and the direction of winds would be altered over a still larger area of the globe. If Lapland and the isthmus of Panama were to subside at the same time, so that icebergs could float CH. v.] THE EVOLUTION OF THE EARTH. 405 through the Baltic to the coast of Prussia, while the Gulf Stream would be diverted into the Pacific Ocean, the climate of Europe might become glacial. Yet either the submergence of Greenland, or the elevation of the East Indian Archi- pelago into a continuous continent, would perhaps suffice to neutralize all these agencies, and restore the genial warmth. In such climatic relations we see vividly illustrated that kind of integration which brings the condition of each part of an aggregate into dependence upon the condition of all the other parts. It is now suf&ciently proved that the development of the earth, like the development of the planetary system to which it belongs, has been primarily an integration of matter and dissipation of motion, and secondarily a change from in- definite homogeneity with relative isolation of parts to definite heterogeneity with relative interdependence among parts. But our survey of telluric evolution is as yet far from complete. While enough has been said concerning the redistributions of matter which have gone on over the face of the globe, nothing has l^een said concerning the far more wonderful and interesting redistributions of the molecular motion which the earth is continually receiving from the sun. Here, as already briefly hinted, we have the chief source of terrestrial heterogeneity. In the chapter on the Law of Evolution, it was observed, as a general truth, that homogeneous forces incident upon a heterogeneous aggregate undergo differentiation and integration. We shall now find this general truth beautifully exemplified in the history of the surface of our planet. At a remote era in that history, the differentiation and integration of solar radiance began gradually to constitute the most important part of the com- plex process of terrestrial evolution. We have now to show how this has been done ; and we shall find it desirable to introduce the subject with an inquiry into the Sources of Terrestrial Energy. CHAPTER VII. THK SOURCES OF TERRESTRIAL ENERGY. At the outset we may state broadly that all terrestrial energy is due either to direct gravitative force, or to the arrest of the centripetal motion produced by gravitative force, either in the earth or in the sun. In other words, the entire series of terrestrial phenomena is the complex product of the earth's internal heat, combined with solar radiance, and with direct gravitative force exercised by the moon and other planets. Beginning with the smallest and least conspicuous of these sources of energy, a mere allusion will suffice for the effects wrought upon the earth by its companion planets through the medium of their tidal action upon the sun. That the phenomena of the aurora borealis, as well as the periodic variations in the position of the magnetic needle, are depen- dent upon the solar spots, is now a well-established doctrine ; and it seems not unlikely that we shall ere long succeed in tracing out other dependences of this sort, — as is shown, for example, in Mr. Meldrum's investigation of the relations between sun-spots and rainfall. And whatever may be the final explanation of the phenomena of sun-spots, there can be little doubt that the periodicity of these phenomena is conditioned by the positions of the vaiious planets, and especially of the giants Jupiter and Saturn, But these CH. VII.] BOVRGEki OF TERRESTRIAL ENERGY. 407 inter-relations, though they may be much more irnxxirtant than is as yet suspected, need not now detain us. Such further effects as may be wrought upon the earth by polarized light sent from the other planets, and by radiance from re- mote stellar systems, may be left out of the account. J^or need we do more than allude to the moon's gravitative force as the chief cause of the oceanic tides, with their resultant geologic phenomena. Passing over all these circumstances, "we come to the still unexpended energy represented by the earth's internal heat, concerning which we need only say that it is the cause of the geologic phenomena classed as igneous. Volcanic eruptions, earthquake shocks, elevations and sub- sidences of continents and ocean-floors, metamorphoses of sedimentary rocks, boiling springs, fractures of strata, and formations of metallic veins, are the various manifestations of this form of terrestrial energy. But all these grand phenomena must be regarded as inj- measurably inferior in variety and importance to those which are due to the transformation of solar radiance. These must be described with somewhat more of detail. First, with the exception of the changes wrought by the tides, all the geo- logic phenomena classed as aqueous are manifestations of transformed solar energy. Pulses of molecular motion pro- ceeding from the sun are stored as reserved energy in masses of aqueous vapour raised from the sea. This energy is again partly given out as the vapour is condensed into rain and falls to the ground. The portion which remains is expended in the transfer of the fallen water through the soil, till it collects in rivulets, brooks, and rivers, and gradually descends to the ocean whence solar radiance raised it, bearing along with it divers solid particles which go to form sedimentary strata. The wind which blew these clouds into the colder regions where they consolidated into rain-drops, was set in motion by solar energy, — since all winds are caused by tlie unequal heating of different parts of the earth's surface. 403 C08MIC PHILOSOPHY. [pt. ii. Molar motion stored up in these vast masses of moving air is given out not only in the driving of clouds, but also in the raising of waves on rivers and oceans ; and it is still further expended in the wearing away of shores and indentation of coast-lines which these waves effect. All the energy thus manifested by rains and rivers, winds and waves, is trans- formed solar radiance. And in like manner, if asked whence came the molar motion exhibited in the transfer of vast masses of sea- water along definite lines, as in the Gulf Stream and other marine currents, we may safely answer — what- ever view we adopt as to the details of these movements — that it was originally due to the heat which so rarefied this water as to make it yield to the pressure of adjacent colder and denser water. And this heat came to the earth in the solar rays. Tlius all movements of gaseous, liquid, and solid matter upon the earth's surface, except volcanic and tidal movements, are simply transformations of the heat which is generated by the progressive integration of the sun's mass. But this is not the end of the matter. Our last sentence implicitly included the phenomena of life among those due to solar radiance, since the phenomena of life, whatever else they may be, are certainly included among the complex movements of gaseous, liquid, and solid matters, which occur upon the earth's surface. Let us note some of the various ways in which molecular motion, sent from the sun, is metamorphosed into vital energy. The seed of a plant, buried in the damp earth, grows by the integration of adjacent nutritive materials, but the energy which effects this union consists in the solar undulations by which the soil is warmed. Diminish, to a certain extent, the daily supply of radiance, as in the long arctic and the short temperate winters, and the seed will refuse to grow. Though nutritive material may be at hand in abundance, there is no molecular motion which the seed can absorb. When the seed grows and shoots up its delicate green stalk, CH. vii.] SOUBCES OF TERRESTRIAL ENERGY. 409 tipped with a pair of leaflets, these leaflets begia to absorb aud transform those more rapid waves of the sunbeam, known as light and actinism. That the plant may continue to grow, by assimilating carbon and hydrogen, it is necessary for the leaf- molecules to decompose the carbonic acid of the atmo- sphere, and for the molecules of the rootlets to decompose the water which trickles through the ground. But before this can be done, the molecules of leaf and rootlet must acquire motor energy, — and this is supplied either directly or in- directly by the sunbeam. The slower undulations, penetrat- ing the soil, set in motion the atoms of the rootlet, and enable them to shake hydrogen-atoms out of equilibrium with the oxygen-atoms which cluster about them in the com- pound molecules of the water. The swifter undulations are arrested by the leaves, where they communicate their motor energy to the atoms of chlorophyll, and thus enable them to dislodge adjacent atoms of carbon from the carbonic acid in which they are suspended. And these cliemical motions, going on at the upper and lower extremities of the plant, disturb the equilibrium of its liquid parts, and thus inaugu- rate a series of rhythmical molar motions, exemplified in the alternately ascending and descending currents of sap. And lastly these molar motions, perpetually replenished from the same external sources, are perpetually expended in the molecular integration of vegetable cells and fibres. Thus all the energy stored up in the plant, both that displayed in the chemical activities of leaves and rootlets, and that which is displayed in circulation and growth, is made up of trans- formed sunbeams. The stately trunk, the gnarled roots, the spreading branches, the rustling leaves, the delicately- tinted blossoms, and the tender fruit, are all — as Moleschott no less truly than poetically calls them — the air-woven children of light. In remote geologic ages untold millions of these solar beams were occupied in separating vast quantities of carbon 410 COSMIC PHILOtiOPUY. [ft. ii. from the dense atmosphere, and incorporating it in the tissues of innumerable forests. Charred by slow heat, and gradually- petrified, this woody tissue became transformed into coal, which now, dug up from its low-lying beds and burned in stoves and furnaces, is compelled to give up the radiance which it long ago purloined from the sun. When placed under the engine- boiler, these transformed sunbeams are again metamorphosed into molar motions of expanding vapour, which cause the rhythmic rise and fall of the piston, and drive the running-gear of the machine-shop or propel the railway-train. In such wise it may be shown that the various agencies which man makes subservient to industrial purposes, are nothing but variously differentiated sunbeams. The windmill is driven by atmospheric currents which the sun set in motion. The water-wheel is kept whirling by streams raised by the sun to the heights from which they are rushing down. And the steam-engine derives its energy from modern or from ancient sunbeams, according as its fires are fed by wood or by coal. But the solar energy stored up by vegetables is given out not only in such mechanical processes, but also in the vital activities of the human beings whose needs such processes supply. The absolute dependence of animal upon vegetal life is illustrated in the familiar fact that animals cannot directly assimilate inorganic compounds. The inorganic water which we drink is necessary to the maintenance of life ; but it percolates untransformed through the tissues and blood-vessels, and it quits the organism in the same chemi- cal condition in which it entered it. And although minute c^uantities of the salt which we daily eat, and of the car- bonates and iodides of iron which we sometimes take as tonics, may perhaps undergo transformation in the tissues ; it is none the less true that the substance of our tissues can only be repaired by means of the complex albuminous mole- cules which solar enei-gy originally built up into the tissiies of CH. vn.] SOURCES fjy TEUliESTRIAL ENEROY. Ul vegetables. Herbivorous animals in each of tlie great classes, feed directly upon vegetable fibre, and so rearrange its mole- cules that the resultant tissues are more higlily nitrogenous than those from which they were formed. More active car- nivorous animals derive from the enormous chemism latent in these nitrogenous fabrics the vital energy displayed in their rapid bounds and in their formidable grip. But the energies which imprisoned this tremendous chemical force in the complex molecules which the animal assimilates, were at first supplied "by sunbeams. Metamorphosed originally into the static energy of vegetable tissue, this sun-derived power is again metamorphosed into the dynamic energy which main- tains the growth of the animal organism. And from the same primeval source comes the surplus energy, which after "the demands of growth or repair have been satisfied, is ex- pended in running, jumping, flying, swimming, or climbing, as well as in fighting with enemies and in seizing and de- vouring prey. Besides these indirect and doubly-indirect methods in which animals differentiate solar enei'gy, there are ways in which the metamorphosis is directly effected. To cite Dr. Carpeu- teir's conclusions, as epitomized by Mr. Spencer : — " The transformation of the unorganized contents of an egg into the organized chick, is altogether a question of heat : with- hold heat and the process does not commence ; supply heat and it goes on while the temperature is maintained, but ceases when the egg is allowed to cool. ... In the meta- morphoses of insects we may discern parallel facts. Experi- ments show not only that the hatching of their eggs is deter- mined by temperature, but also that the evolution of the pupa into the imago is similarly determined ; and may be im- mensely accelerated or retarded according as heat is artificially supplied or withheld," The phenomena thus briefly cited are to be classed under the general head of organic stimulus ; and in a wide sense, one might almost say that all stimulus 412 COSMIC PHILOSOPHY. [pt. u. is the absorption of vital energy which was originally solar. Sunlight stimulates animals indirectly, as in the case of actinise which are made more vivacious when neighbouring sea-weed, smitten by sunbeams, pours oxygen into the water in which they move ; and also in the case of hard-worked men who gain vigour from the judicious use of vegetable narcotics. The waves of motor energy which the human organism absorbs in whiffs of tobacco-smoke, are but a series of pulsations of transformed sunlight.'' But animals are also directly stimulated by the solar rays, as in the cases of insects which begin to fly and crawl in early summer, and of hybernating mammals which emerge from their retreats at the approach of warm weather. By its stimulating effect on the retina, and thence on the medulla oblongata, sunlight, quickens the breathing and circulation in higher animals, and thus facilitates the repair of tissue. In the night we exhale less carbonic acid than in the daytime. Again the stunted growth and pale sickly faces of men and women who live in coal-mines, or in narrow streets and dark cellars, are symptoms traceable to anaemia, or to a deficiency of red globules in the blood. Whence it seems not improbable that the formation of red globules, like the formation of sap in plants, may be in some way directly assisted by solar undu- lations. Mysteriously allied with the vital phenomena of nutrition, innervation, and muscular action, are the psychical pheno- mena of feeling and thought. Though (as previously hinted and as I shall hereafter endeavour to prove) the gulf between the phenomena of consciousness and all other phenomena is an impassable gulf, which no future extension of scientific ' As the poet-philosopher Eedi says of wine : — " Si bel sangue k un raggio acceso Di quel Sol che in eiel vedete ; E limase avvinto e preso Di piu grappoli alia rete." Bacco in Toscana; Opere, torn. i. p. 2. CH. VII.] SOURCES OF TERRESTRIAL ENERGY. 413 knowledge is likely to bridge over; it is nevertheless un- questionable both that every change in consciousness is con- ditioned by a chemical change in ganglionic tissue, and also that there is a discernible quantitative correspondence be- tween the two parallel changes. Let us glance for a moment at certain facts which will serve to illustrate and justify these propositions. Those changes of consciousness which are variously classi- fied as thoughts, feelings, sensations, and emotions, cannot for a moment go on save in the presence of certain assign- able physical conditions. The first of these conditions is complete continuity of molecular cohesion among the parts of nerve-tissue. A nerve which is cut does not transmit sensori-motor im- pulses ; and even where the continuity of molecular equili- brium is disturbed, without overcoming cohesion, as in a tied nerve, there is no transmission. It is in the same way that pressure on the cerebrum instantly arrests consciousness when a piece of the skull is driven in by a blow, and slowly arrests it when coma is produced by congestion of the cerebral arteries. Now the need for complete continuity of molecular equilibrium, both in the white and in the grey tjssue, is a fact of no meaning unless a molecular rearrange- ment is an indispensable accompaniment of each change in consciousness. Secondly, the presence of a certain amount of nutritive material in the cerebral blood-vessels is essential to every change in consciousness ; and upon the quantity of material present depends, within certain limits, the rapidity of the changes. While rapid loss of blood causes fainting, or total stoppage of conscious changes, it is also true that lowered nutrition, implying deficiency of blood, retards the rate and interferes with the complication of mental processes. In a state of extreme anaemia not only does thinking go on slowly, but the manifold compounding and recompounding 414 COSMIC PHILOSOPHY. [pt. ir. of conscious changes, which is implied in elaborate quanti- tative reasoning, cannot go on at all. ISTow the need for the constant presence of nutritive material is a meaningless fact unless each change in consciousness is dependent upon a molecular transfer between the nutritive material and the nerve-substance. Thirdly, the maintenance of conscious changes requires the presence of certain particular materials in the blood, and the absence, in any save the smallest proportions, of certain other materials ; while there are yet other materials upon the presence of which the rate and complication of conscious changes largely depend. The familiar fact that consciousness cannot for an instant continue unless oxygen is in contact with the grey tissue of the cerebrum, is alone sufficient to prove that no conscious change is possible, save as the accompaniment of a chemical change. On the other hand, the presence of carbonic acid or of urea in consider- able quantities retards the rate and prevents the elaboration of thinking ; and in still larger quantities it puts an end to consciousness. And in similar wise the effects of alcohol, opium, and hemp, as well as of that Siberian fungus whose inhaled vapour makes a straw in the pathway look too large to be jumped over, show us most vividly how immediate is the dependence of complex mental operations upon chemical changes. Fourthly, the fact that the vigour and complexity of mental manifestations bear a marked ratio to the weight of the brain, to the amount of phosphorus contained in its tissue, and to the number and intricacy of the fine sinuous creases in the grey surface of the hemispheres, shows plainly that changes in consciousness are conditioned both by the amount and by the arrangement of nerve-material. Fifthly, we may see a like significance in the facts that the amount of alkaline phosphates excreted by the kidneys varies with the amount of mental exertion ; and that emo- CH. vii.] SOURCEB OF TERRESTRIAL ENERGY. 415 tional excitement so alters the composition of the blood that infants have been poisoned by milk secreted by their frightened or angry mothers. And lastly may be cited the beautiful experiments of Prof. Lombard, in which the heat evolved by the cerebrum during the act of thinking vs^as not only detected but measured, and found to vary according to the amount of mental activity going on. These, though the most conspicuous, are but a few among the facts which force upon the physiologist the conclusion that there is no such thing as a change in consciousness which has not for its correlative a chemical change iu nervous tissue. Hence we may the better understand the significance of familiar facts which point to a quantitative correlation between certain states of consciousness and the outward phenomena which give rise to them. A bright light, as measured by the photometer, produces a more vivid state of consciousness than a dim light. Substances which the thermometer declares to be hot are, under normal circumstances, mentally recognized as being hot. The con- sciousness of a sound varies in vividness with the violence of the concussions to which the sound is due. And bodies which are heavy in the balance excite in us correlative sensations of strain when we attempt to move them. Con- versely the molar motions by which our states of feeling are revealed externally, have an energy proportional to the intensity of the feeling ; witness the undulations indicative of pain, which, beginning with a slight twitching of the facial muscles, may end in spasmodic convulsions of the whole body. And of like import is the fact that gentle emotions, like slight electric and narcotic stimuli, agreeably quicken the heart's contractions ; while violent emotions, suddenly awakened, may stop its beating as effectually as a stroke of lightning or a dose of concentrated prussic acid. The bearings of such facts as these upon our theories of mental phenomena will be duly considered in future chapters. 416 COSMIC PHILOSOPHY. [pt. ii. At present we have only to regard them as furnishing con- clusive evidence that the phenomena which are subjectively known as changes in consciousness, are objectively corre- lated with molecular motions of nerve-matter which are seen, in an ultimate analysis, to be highly differentiated forms of solar radiance. "Waves of this radiance, speeding earthward from the sun at the rate of more than five hundred trillions per second, impart their motor energy to the atoms which vibrate in unison in the compound molecules of the growing grass. Cattle, browsing on this grass, and inte- grating portions of it with their tissues, rearrange its mole- cules in more complex clusters, in which the tremendous chemical energy of heat-saturated nitrogen is held in equili- brium by the aid of these metamorphosed sunbeams. Man, assimilating the nitrogenous tissues of the cow, builds up these clusters of molecules, with their stores of sun-given and sun-restrained energy, into the wondrously complex elements of white and grey nerve-tissue, which incessantly liberating energy in decomposition, mysteriously enable him to trace and describe a portion of the astonishing metamorphosis. When one takes a country ramble on a pleasant summer's day, one may fitly ponder upon the wondrous significance of this law of the transformation of energy. It is wondrous to reflect that all the energy stored up in the timbers of the fences and farmhouses which we pass, as well as in the grind- stone and the axe lying beside it, and in the iron axles and heavy tires of the cart which stands tipped by the roadside ; all the energy from moment to moment given out by the roaring cascade and the busy wheel that rumbles at its foot, by the undulating stalks of corn in the field and the swaying branches in the forest beyond, by the birds that sing in the tree-tops and the butterflies to which they anon give chase, by the cow standing in the brook and the water which bathes her lazy feet, by the sportsmen who pass shouting in the CH. VII.] THE SOURCES OF TERRESTRIAL ENERGY. 417 distance as well as by their dogs and guns ; that all this multiform energy is nothing but metamorphosed solar radi- ance, and that all these various objects, giving life and cheer- fulness to the landscape, have been built up into their cognizable forms by the agency of sunbeams such as those by which the scene is now rendered visible. We may well declare, with Prof. Tyndall, that the grandest conceptions of Dante and Milton are dwarfed in comparison with the truths which science discloses. But it seems to me that we may go farther than this, and say that we have here reached some- thing deeper than poetry. In the sense of illimitable vast- ness with which we are oppressed and saddened as we strive to follow out in thought the eternal metamorphosis, we may recognize the modern phase of the feeling which led the ancient to fall upon his knees, and adore — after his own crude, symbolic fashion — the invisible Power whereof the infinite web of phenomena is but the visible garment. VOL. I. li E CHAPTER VIII. THE BEGINNINGS OF LIFE. Amid the chaos of ideas concerning vital phenomena which prevailed until quite recent times, it was hardly strange that organisms, even of a high order of complexity, should have been supposed to be now and then directly evolved from life- less matter, under favourable circumstances. Every reader of ancient literature will remember how Aristseus succeeded in replacing his lost swarm of bees ; and the sanction thus accorded by so erudite a poet as Virgil to the popular belief in the generation of insects from putrescent meat, is good evidence that the impossibility of such an occurrence had not yet been suspected, or at least had never been duly appreciated. StiU. more important is the testimony of Lucretius — who, as Prof Huxley well says, " had drunk deeper of the scientific spirit than any other poet of ancient or modern times except Goethe " — when he alludes to the primordial generation of plants and animals by the universal mother Earth. It is, however, straining words somewhat beyond their usual meanings to call such speculations " scientific." They were the product of an almost total absence of such knowledge as is now called scientific. It was possible to infer that such highly organized creatures as hymenopterous insects, suddenly appearing in putrescent meat, were spontaneously generated there, only because so CH. VIII.] TH:E beginnings of life. 419 little was definitely known about the relations of organisms to one another and to the inorganic world. Accordingly with the very beginnings of modern biological knowledge, and with the somewhat more cautious and systematic em- ployment of induction characteristic of the seventeenth century, the old belief in spontaneous generation was called in question. By a series of very simple but apt experiments, in which pieces of decaying meat were protected from maggots by a gauze covering, the illustrious Eedi proved, to the satisfaction of everyone, that the maggots are not pro- duced from the substance of the meat, but from eggs de- posited therein by flies. So conclusive were these experi- ments that the belief in spontaneous generation, which had hitherto rested chiefly upon phenomena of this sort, was almost universally abandoned, and the doctrine that every living thing comes from some living thing — omne vivum ex vivo — received that general acceptance which it was destined to retain down to the present time. "With the progress of biological knowledge, as the complex structures and regular modes of growth of the lower animals began to be better understood, and as the microscope began to disclose the existence of countless forms of life infinitesimal in size but complicated in organization, many of which were proved to be propagated either by fission or by some kind of germina- tion, the doctrine omne vivum ex vivo became more and more implicitly regarded as a prime article of faith, and the hypo- thesis of spontaneous generation was not merely scouted as absurd, but neglected as unworthy of notice. Philosophical theories conspired with observation and ex- periment to bring about this result. The doctrine omne vivum ex vivo consorted well with the metaphysical hypo- thesis of an archceus or " vital principle," by means of which Stahl and Paracelsus sought to explain the dynamic pheno- mena manifested by living organisms. In those days when it was the fashion to explain every mysterious group of E E 2 420 COSMIC PHILOSOPHY. [pt. ii. phenomena by imagining some entity behind it, the activitiea displayed by living bodies were thought to be explained ■when they were called the workings of a " vital principle " inherent in the living body, but distinct from it and surviv- ing unchanged amid its manifold alterations. If a stone falls to the ground, that is a manifestation of gravitative force ; but if a stream of blood come rushing through a capillary tube and certain compound molecules of albuminous matter are taken from it and retained by the adjacent tissue, then, according to the vitalistic theory, the " vital principle " is at work. During life this " principle " continues to work ; but at death it leaves the organism, which is then given up to the mercy of physical forces. Such was the theory of life which was held by many physiologists even at a time within the recollection of persons now living ; and it doubtless still survives in minds uninstructed in modern science. So long as this doctrine held undisputed sway, the belief that aU life proceeds from life was not likely to be seriously im- pugned. For whence, save by derivation from some other " principle " like unto itself, could this mysterious " vital principle " arise ? Besides all this, the Doctrine of Evolution had not yet been originated ; all things were supposed to have been created at once in their present condition ; and, as no need was felt of explaining scientifically the origin of the highest organisms, so there was no disposition to inquire into the origin of those lowest in the scale. A series of separate creative acts was supposed to account for the whole. Strengthened by these metaphysical conceptions, the doc- trine omjie, vivum ex vivo remained in possession of the field for two centuries. Phenomena apparently at variance with it — such as the occasional discovery of animalcules in closed vessels — were disposed of by the hypothesis, devised by Spallanzani, that the atmosphere is full of invisible germs which can penetrate through the smallest crevices. This hypothesis is currently known as "panspermatism," or the CH. vni.] THE BEGINNINGS OF LIFE. 4'21 " theory of omnipresent germs," or (less cumbrously) as the " germ -theory.'' Now, as concerns the germ-theory, to which appeal is un- hesitatingly made whenever the question of spontaneous generation is discussed, it must be admitted to be extremely plausible, yet we must not forget that it has never been actually demonstrated : it has not been proved that the germ-theory can do all that its advocates require it to do. It may well be the case that the air is everywhere full of germs, too small to be seen, which are capable of giving rise to all the organisms of which there is any question in the controversy about spontaneous generation : nevertheless this has not been rigorously demonstrated. The beautiful researches of Prof Tyndall have indeed proved that the atmo- sphere is everywhere filled with solid particles, in the absence of which it would not be luminous ; and it is fair to suppose that among these particles there are always to be found some which are the germs of monads and bacteria. Still this can hardly be taken for granted; and Dr. Bastian is right in reminding us that it is reasoning in a circle to assume the presence of germs that cannot be detected, merely because there is no other way of accounting for the presence of monads and bacteria in accordance with the doctrine of Eedi. For in all discussions concerning spontaneous generation it should be borne in mind that the doctrine om7i6 vivum ex vivo is itself on trial for its life, and cannot bo summoned to the witness-box. The very point to be ascertained is whether this doctrine, which is admitted to hold good in the case of all save the lowest forms of life, holds good also of these. The doctrine rests entirely upon induction ; and while, in many cases, it is legitimate to infer a universal proposition from a limited induction of instances, it is not legitimate to do so in the present case. Tor the fact that innumerable highly specialized types of animal and vegetal life are kept up solely by generation ex vivo, can in nowise 422 COSMIC PHILOSOPHY. [pt. ir. prove that other living things, which are nearly or quite destitute of specialization, may not have their ranks recruited by a fresh evolution from not-living materials. Along with the absence of specialized structure, it may turn out that there is an absence of other characteristics once supposed to be common to all living things. This will be more clearly understood as we proceed to consider the change which the last half-century has wrought in the theories of life with which Eedi's doctrine has hitherto been implicated. Tlie hypothesis of a " vital principle " is now as completely discarded as the hypothesis of phlogiston in chemistry, or as the Ptolemaic theory in astronomy : no biologist with a reputation to lose would for a moment think of defending it. The great discoveries concerning the sources of terrestrial energy, illustrated in the foregoing chapter, have made it henceforth impossible for us to regard the dynamic phenomena manifested by living bodies otherwise than as resulting from the manifold compounding of the molecular forces with which their ultimate chemical constituents are endowed. He ncefo rth the difference between a living and a not-living body is seen to be a difference of degree^jiot^of kind, — a difference dependent solely on the far greater mole- " cular complexity of the former. As water has properties that belong not to the gases which compose it, so protoplasm has properties that do not belong to the inferior compounds of which it is made up. The crystal of quartz has a shape which is the resultant of the mutual attractions and repulsions of its molecules ; and the dog has a shape which is ultimately to be explained in the same way, save that iji this case the pro- cess has been immeasurably more complex and indirect. Such, in brief, is the theory by which the vitalistic doctrine of Stahl has been replaced. Instead of a difference in kind between life and not-life, we get only a difference of degree ; BO that it again becomes credible that, under favouring cir- cumstances, not-life may become life. CH. viii.] THE BEQINNINGS OF LIFE. 423 lu the next place the overthrow of the dogma of fixity of species, and the consequent general displacement of the Doctrine of Creation by the Doctrine of Evolution, have made the scientific world familiar with the conception of the development of the more specialized forms of life from less specialized forms ; and thus the development of the least specialized forms of life from the most complex forms of not-life ceases to seem absurd, and even acquires a sort of pro- bability. And finally, the researches of geologists, showing that our earth's surface was once " melted with fervent heat," and confirming the theory of the nebular origin of our planet, have rendered it indisputable that there must once have been a time when there was no life upon the earth ; so that cer- tainly at some time or other, though doubtless not by a single step but by a number of steps, the transition from not- life to life must have been made. Hence the doctrine omne vivum ex vivo, as now held, means neither more nor less than that every assemblage of organic phenomena must have had as its immediate antecedent some other assemblage of phenomena capable of giving rise to it : in other words, the doctrine has become little more than a specialized corollary from the persistence of force. In the case of all save the lowest organisms, the only antecedent phenomenon capable of giving rise to the organism in question has been inductively proved to be some other organism. But in the case of the lowest organisms it is theoretically possible that the requisite antecedent may in some instances be an assemblage of un- organized materials ; and it remains for induction to show whether this possibility is ever actually realized or not, under existing terrestrial conditions. Such being the modification which modern discoveries have imposed upon the doctrine omne vivum ex vivo, it need hardly be added that the hypothesis of spontaneous genera- tion has undergone a no less important change. The theory that an organism which is to any extent specialized in struc- 424 COSMIC PHILOSOPHY. [pt. ii. ture can arise directly from a union of unorganized elements is ruled out of court. Such a conception, though it might be harmonized with the hypothesis of special creations, is utterly condemned by the Doctrine of Evolution. So long as it was possible to believe that enormously complex birds and mammals were somehow conjured into existence, like Aladdin's palace, in a single night, by a kind of enchantment which philosophers sought to dignif}^ by calling it " creative fiat," it might well have seemed possible for animalcules to be spontaneously generated in air-tight flasks, or even for maggots to arise de novo in decaying meat. Such a view might have been logically defensible, though it was not the one which actually prevailed. But now, in face of the proved fact that thousands of years are required to effect any con- siderable nrodification in the specific structures of plants and animals, it has become impossible to admit that such specific structures can have been acquired in a moment, or otherwise than by the slow accumulation of minute peculiarities. Hence " spontaneous generation " can be theoretically ad- mitted only in the case of living things whose grade of com- position is so low that their mode of formation from a liquid solution may be regarded as strictly analogous to that of crystals. And when the case is thus stated it becomes obvious that the phrase " spontaneous generation " is anti- quated, inaccurate, and misleading. It describes well enough the crude hypothesis that insects might be generated in putrefying substances without any assignable cause ; but it is not applicable to the hypothesis that specks of living proto- plasm may be, as it were, preciipitaUd from a solution con- taining the not-living ingredients of protoplasm. If such an origination of life can be proved, none will maintain that it is " spontaneous," since all will regard as the assignable cause the chemical affinity exerted between the enormously com- plex molecules which go to make up the protoplasm. No one speaks of "spontaneous crystallization"; and the ideas CH. viii.] TUB BEGINNINGS OF LIFE. 423 Biiggested by the use of the word " spontaneous " are such as to detract seriously from its availableness as a scientific term. We need a phrase which shall simply describe a fact, without any admixture of hypothesis ; and we may cordially recommend, as such a phrase. Dr. Bastian's arche- hiosis, which, without violence to etymology, may be said to mean " life in its beginning," — or, more freely, " beginning of life." With these preliminaries, the precise question now at issue between the believers in " spontaneous generation " and their opponents may be stated as follows : — Can archehiosis be made to occur at the present day by artificial means ? Or, to be still more accurate, Has archebiosis actually been made to occur at the 2^fcsent day by artificial means ? Is it possible for the experimenter, without any assistance from life already existing, to obtain living things, merely by bringing together the chemical constituents of protoplasm, under suitable phy- sical conditions ? Or, granting the possibility, can it be proved that living things have actually been thus obtained ? To this twofold question there are returned diverse answers. On the one hand, Dr. Bastian maintains that himself and other experimenters have actually seen archebiosis artificially brought about. On the other hand, it is likely to be main- tained by most competent critics that, while there may be no good reason for denying the possibility of such a triumph of experiment, we have not yet sufficient proof that it has been really achieved. It should not be forgotten that the decision of the more general question of the origin of life on the earth's surface does not depend upon the way in which this special contro- versy is decided. While it is true that the success of ex- periments like those of Dr. Bastian would furnish conclusive inductive proof of archebiosis, it is also true that their com- plete failure can in no wise be cited in evidence against the doctrine. On the one hand, the artificial production of living 426 COSMIC PHILOSOPHY. [pt. ii. things, by giving us ocular testimony to the beginnings of life, would no doubt enlighten us considerably as to the physical and chemical conditions under which life originates ; and it is, therefore, highly desirable that experimenters should be able to construct living protoplasm in the labora- tory, just as it was desirable, a few years ago, that chemists should be able to produce such organic compounds as alcohol, sugar, and urea, — substances which until lately were thought to be, for some mysterious reason, inaccessible to human art, but which are now constructed with ease. But on the other hand, even the demonstrated impossibility of producing living things artificially would not weigh a grain in the scale against the doctrine that archebiosis may now occur, and must at some time have occurred, in the great laboratory of nature. That an evolution of organic existence from in- organic existence must at some time have taken place, is rendered certain by the fact that there was once a time when no life existed upon the earth's surface. That such evolution may even now regularly take place, among such living things, for instance, as the Bathyhiiis of Haeckel — a sort of albu- minous jelly growing in irregular patches on the sea-bottom — is perhaps not impossible. But that such evolution has been known to take place in air-tight flasks containing de- coctions of hay, and has moreover resulted in the formation of organisms like vibrios and fungus-spores, is quite another proposition, which the assertor of archebiosis is in no way bound to maintain, and with the fate of which he need not feel himself vitally concerned. The question of " spontaneous generation," then, is but a part, and not the most essential part, of the question as to the origin of life ; and we need not be surprised at finding among Dr. Bastian's opponents such an avowed evolutionist as Prof. Huxley. Practically, moreover, the question at issue between the advocates of " spontaneous generation" and their antagonists is even narrower than appears from the above CH. viii.] TIIM BEGINNINGS OF LIFE. 427 statement of it. As practically conducted, the dispute is confined to the question whether certain particular low forms of life — known as vibrios, bacteria, torulae, and monads — which appear in putrescence or in fermentation, are produced by archebiosis, or are propagated from germs conveyed in the atmosphere. If Dr. Bastian's position with reference to this question is destined to become substantiated, his work may perhaps mark an epoch in biology hardly less important than that which was inaugurated by Mr. Darwin's " Origin of Species.'' Unfortunately, the kind of proof which is needed for Dr. Bastian's main thesis is much more diificult, both to obtain and to estimate properly, than the kind of proof by which the theory of natural selection has been substantiated. In the latter case what was needed was some principle of interpretation which should account for the facts of the classification, embryology, morphology, and distribution of plants and animals, without appealing to any other agencies than such as can be proved to be actually in operation ; and it is because the theory of natural selection furnishes such a principle of interpretation that it has met with such ready acceptance from the scientific world.^ On the other hand, the fate of the theory of archebiosis, in the shape in which it is held by Dr. Bastian, depends upon the issue of a series of experiments of extraordinary delicacy and difficulty, — experiments which are of value only when performed by scientific experts of consummate training, and which the soundest critic of inductive methods must find it perilous to interpret with confidence, unless he has had something of the training of an expert himself. For however easy it may seem to the uninitiated to shut up an organizable solution so securely that organic germs from the atmosphere cannot even be imagined capable of gaining access to it, this is really one of the most arduous tasks which an experimenter has ever ^ I am here anticipating the argument of the two following chapters. 428 COSMIC PHILOSOPHY. [pt. ii. had set before him. Yet to such rigour of exclusion is the inquirer forced who aims at settling the question by the direct application of the Method of Difference. And thus the question at issue is reduced to that unpromising state in which both parties to the dispute are called upon to per- form the apparently hopeless task of pro\dng a negative. When living things appear in the isolated solution, the adherents of the germ-theory are always able to point out some imaginable way in which germs might have got in. On the other hand, when the panspermatists adduce instances in which no living things have been found, the believers in archebiosis are able to maintain that the failure was due, not to the complete exclusion of germs from without, but to the exclusion of some other physical condition essential to the evolution of living matter. And from this closed circle of rebutting argiiments there seem at present to be no means of egress. But in so far as the interpretation of Dr. Bastian's experi- ments is intended to throw light upon the beginnings of life on the earth, there is a manifest anomaly in tire use of such liquid menstrua as the infusions of hay, turnip, beef, or urine, which Dr. Bastian ordinarily employs. Whatever archebiosis may occur in such media can hardly be like the process by which living things first came into existence ; since the ex- istence of the beef or turnip implies the previous existence of organisms high in the scale. The positive detection of archebiosis in these and similar menstrua will, of course, have an interest of its own ; but, as Mr. Spencer well says, " a tenable hypothesis respecting the origin of organic life must be reached by some other clew than that furnished by' experiments on decoction of hay and extract of beef" To meet this objection Dr. Bastian has in some experiments used only inorganic substances, like phosphate of soda, and the oxalate, tartrate, or carbonate of ammonia, in which the elements essential to the formation of protoplasm are present. CH. vni.] THE BUGINNINGS OF LIFE. 429 Yet in such menstrua as these he believes that he has found even fungus-spores " spontaneously " generated. The contrast here vividly brought before us draws attention to what would seem to be one of the weakest points in Dr. Bastian's theory. It is a long way from tartrate of ammonia and phosphate of soda to the spores of a fungus. It seems too long a way to be traversed in a few days or weeks amid merely the simple conditions which exist within a closed flask. A fungus-spore is not mere shapeless protoplasm. In it, as in the bacterium and the vibrio, there is a visible specialization of structure, albeit a slight specialization. These infusoria are " lowest organisms," no doubt : still they are really organisms and not merely masses of organic matter. They have forms which are more or less persistent ; and in this fact is to be seen the strongest of the objections which may be urged d priori against Dr. Bastian's views. For organic form is a circumstance into which heredity largely enters ; and where we find organisms even so simple as the jointed rods which are called vibrios, it is difScidt, on theoretical grounds, not to accredit them with a regidar organic parentage. Such considerations cannot weigh against a crucial experiment ; but in the present state of the ques- tion they are entitled to serious attention. Dr. Bastiau argues, with great ingenuity, that just as crystals, growing in a liquid menstruum, take on shapes that are determined by the mutual attractions and repulsions of their molecules, so do these colloidal bodies, which we call monads and bacteria, arising by " spontaneous generation " in liquid menstrua, take on . forms that are similarly determined. The analogy, however, is not exact. I am not disposed to deny that the shape of a bacterium, or indeed of a wasp, a fish, a dog, or a man, is due, quite as much as the shape of a crystal of snow or quartz, to the forces mutually exerted on each other by its constituent molecules. But it must be remembered that in the case of an organism, the direction of these forces depends. 430 COSMTC FHILOSOPHY. [pt. ir. in a way not yet explained, upon tlie directions in which they have been exerted by ancestral organisms. In other words a set of definite tendencies has been acquired during the slow evolution of organic life ; and it may well be doubted that, even in the case of the bacterium, a tendency toward the formation of single or double nuclei can have been gained during the evolution of a single generation of individuals. For in colloidal matter, as such, there is no definite tendency toward the formation of nuclear spots, such as are seen in bacteria. It is a main characteristic of colloids, as contrasted with crystalloids, not to have any specific form. It is, therefore, hard to believe that, during the decomposition of some saline liquid, the freed elements not only recombine into a colloid, but even go so far as to take on the specific shape of a bacterium or vibrio, When any such succession of phenomena appears to occur, it clearly points to the ill-understood but imperative fact of heredity through a long past. Until this difficulty is either cleared away by trustworthy deduction, or overridden by some crucial experiment, I do not think that the advocates of " spontaneous generation " can be said to have made out their case ; and such an abstruse ques- tion is here opened that it is not likely soon to be settled. For the present, in representing to ourselves how life may have originated upon the earth, we are reduced to a few most general considerations. However the question may eventually be decided as to the possibility of archebiosis occurring at the present day amid the artificial circumstances of the laboratory, it cannot be denied that archebiosis, or the origi-, nation of living matter in accordance with natural laws, must have occurred at some epoch in the past. That life has not always existed upon the earth's surface is certain; and the following considerations will show that in its first appear- ance there need not have been anything either sudden or abnormal. CH. VIII.] TJIE BEQINNINGH OF LIFE. 431 When our earth, refusing to follow in their retreat the heavier portions of the solar nebula, began its independent career as a planet, its surface was by no means so hetero- geneous as at present. We may fairly suppose that the tem- perature of that surface cannot have been lower than the temperature of the solar surface at the present time, which is estimated at three million degrees Fahrenheit, or some four- teen thousand times hotter than boiling water. At such a temperature there could have been no formation of chemical compounds, so that the chief source of terrestrial hetero- geneity did not exist ; while physical causes of heterogeneity were equally kept in abeyance by the maintenance of all things in a gaseous state. We have now to note how the mere consolidation and cooling of this originally gaseous planet must have given rise to the endless variety of struc- tures, organic as well as inorganic, which the earth's surface now presents. The origination of life will thus appear in its proper place, as an event in the chemical history of the earth. Let us see what must have been the inevitable chemical consequences of the earth's cooling. In a large number of cases heat is favourable to chemical union, as in the familiar instance of lighting a candle, a gas- jet, or a wood-fire. The molecules of carbon and oxygen, which will not unite when simply brought into juxtaposition, nevertheless begin rapidly to unite as soon as their rates of undulation are heightened by the intense heat of the match. In like manner the phosphoric compound with which the end of the match is equipped refuses to take up molecules of atmo- spheric oxygen, until its own molecules receive an increment of motion supplied by the arrested molar motion of the match along a rough surface. So oxygen and hydrogen do not com- bine when they are simply mingled together in the same vessel ; but when sufficiently heated they explode, and unite to form steam. In these, and in many other cases, a certain amount of heat causes substances to enter into chemical 432 COSMIC PBILOSOPHY. [pt. ii- union. But it is none the less true that an enormous supply of heat implies such violent molecular undulation as to render chemical union impossible. Since the mode of attractive force known as chemism acts only at infinitesimal distances, the increase of thermal undulation, which at first only causes such a molecular rearrangement as to allow mutually- attracting molecules to rush together, must at last cause such a separation of particles that chemism will be unable to act. This inference from known laws of heat is fully verified by experiment, in the case of all those compounds which we can decompose by such thermal means as we have at command. Speaking generally, the most complex compounds are the most unstable, and these are the soonest decomposed by heat. The highly complex organic molecules of fibrine and albumen are often separated by the ordinary heat of a summer's day, as is witnessed in the spoiling of meat. Supersalts and double salts are decomposed at lower temperatures than simple salts ; and these again yield to a less amount of heat than is re- quired to sunder the elements of deutoxides, peroxides, etc. The protoxides, which are only one degree more complex than simple elements, withstand a still higher temperature, and several of them refuse to yield to the greatest heat which we can produce artificially. No chemist, however, doubts that a still greater heat would decompose even these. We may thus picture to ourselves the earth's surface as at the outset composed only of uncombined elements, of free oxygen, hydrogen, nitrogen, carbon, sulphur, etc., and of iron, copper, sodium, and other metals in a state of vapour. With the lowering of this primitive temperature by radiation, chemical combinations of greater and greater heterogeneity became gradually possible. First appeared the stable binary compounds, such as water and the inorganic acids and bases. After still further lowering of temperature, some of the less stable compounds, such as salts and double salts, were enabled to appear on the scene. At a later date came the OH. VIII.] THE BEOINNINGt^ OF LIFE. 433 Still more heterogeneous and unstable organic acids and ethers. And all this chemical evolution must have taken place before the first appearance of living protoplasm. Upon these statements we may rest with confidence, since they are immediate corollaries from known properties of matter. When it is asked, then, in what way were brought about the various chemical combinations from which have resulted the innumerable mineral forms which make up the crust of the globe, the reply is that they were primarily due to the unhindered working of the chemical affinities of their con- stituent molecules as soon as the requisite coolness was obtained. As soon as it became cool enough for oxygen and hydrogen to unite into a stable compound, they did unite to form vapour of water. As soon as it became cool enough for double" salts to exist, then the mutual affinities of simple binary compounds and single salts, variously brought into juxtaposition, sufficed to produce double salts. And so on, throughout the inorganic world. Here we obtain a hint as to the origin of organic life upon the earth's surface. In accordance with the modern dynamic theory of life, we are bound to admit that the higher and less stable aggregations of molecules which constitute protoplasm were built up in just the same way in which the lower and more stable aggregations of moleciiles which constitute a single or a double salt were built up. Dynamically, the only difference between carbonate of ammonia and protoplasm, which can be called fundamental, is the greater molecular complexity and consequent instability of the latter. We are bound to admit, then, that as carbonic acid and ammonia, when brought into juxtaposition, united by virtue of their inherent properties as soon as the diminishing temperature would let them ; so also carbon, nitrogen, hydrogen, and oxygen, when brought into juxtaposition, united by virtue of their inherent properties into higher and higher multiples as fast as the diminishing temperature would let them, until at VOL. I. F F 434 COSMIC PHILOSOPHY. [pt. ii. lafet living protoplasm was the result of the long-continued process. While by following such considerations as these into greater detail the mode in which protoplasm must have arisen may by and by be partially comprehended, it is at the same time true that the ultimate mystery — the association of vital pro- perties with the enormously-complex chemical compound known as protoplasm — remains unsolved. Why the substance protoplasm should manifest sundry properties which are not manifested by any of its constituent substances, we do not know ; and very likely we shall never know. But whether the mystery be for ever insoluble or not, it can in no wise be regarded as a solitary mystery. It is equally mysterious that starch or sugar or alcohol should manifest properties not dis- played by their elements, oxygen, hydrogen and carbon, when uncombined. It is equally mysterious that a silvery metal and a suffocating gas should by their union become trans- formed into table-salt. Yet, however mysterious,' the fact remains that one result of every chemical synthesis is the manifestation of a new set of properties. The case of living matter or protoplasm is in nowise exceptional. In view of these considerations it may be held that the evolution of living things is a not improbable concomitant of the cooling down of any planetary body which contains upon its surface the chemical constituents of living matter. It may perhaps turn out that we can no more reproduce in the laboratory the precise groups of conditions under which living matter was first evolved than we can obtain direct testimony as to the language and civilization of our pre-historic ances- tors. But, just as it is conceded to be possible, by reasoning upon established philological principles, to obtain some trust- worthy results as to the speech and culture of the pre-historic Aryans, so it must be admitted that, by reasoning upon known facts in physical science, we may get some glimpse of the circumstances which must have attended the origin of living CH. vin.] THE BEGINNINGS OF LIFE. 435 aggregations (tf matter. By following out this method new light will no doubt eventually be thrown upon the past his- tory of our planet, and a sound basis will be obtained for conjectures regarding the existence of living organisms upon some of our neighbour worlds. In this account of the matter we have completed, so far as is needful for the purposes of this work, our exposition of the evolution of the earth. Combining the results obtained in the three foregoing chapters, we may contemplate in a single view the wonderful advance in determinate multi- formity which has restdted from the integration of the earth's matter, with the accompanying dissipation of its internal motion. We have witnessed this process of evolution as manifested in geologic and meteorologic phenomena ; we have followed the wondrous differentiations and integrations of the molecular motion which the cooling and consolidating earth has received from the centre of our system ; and finally, from that very cooling and consolidation upon which all the fore- going phenomena are dependent, we have showfi that there must naturally have ensued a progressive chemical hetero- geneity, resulting at last in the genesis of compounds mani- festing those properties which we distinguish as vital. Thus the continuity in cosmic evolution is grandly exhibited, and we see more clearly than ever that between the various pro- vinces of natural phenomena there are no sharp demarca- tions. As the geologic development of the earth is but a specialized portion of the whole development of the solar system, — a portion which we separate from the rest and assign to a special science, solely for convenience of study ; so the development of living matter is but a specialized por- tion of the whole development of the earth, and it is only for reasons of convenience that the formation of primeval protoplasm is assigned to a different science from that which deals with the formation of limestone or silica. Though as we advance from a lower grade of heterogeneity to a higher F F 2 4:!6 GOSMIG PHILOSOPHY. [ft. ii. grade, we encounter differences of property or of functional manifestation which we may broadly classify as differences of kind, the conclusion is nevertheless forced upon us that such differences of kind are ultimately reducible to dif- ferences of degree, and that at bottom there is no break whatever in the continuity of the process of Evolution. It is not pretended, however, that these considerations fulfil all the requirements of a scientific explanation of the genesis of life. Essentially sound as I believe them to be, they do but point out the direction in which an explanation is to be sought. A complete explanation of the origin of life must include not only a statement of the general condi- tions under which life originated, such as I have here attempted to offer, but also a statement of the specific com- bination of circumstances which gave rise to such an event. If Dr. Bastian's theory of archebiosis can be inductively establislied, it may possibly help us to such a statement. But the considerations above adduced make it probable that a wider view of the case is needful than is implied in Dr. Bastian's researches. It seems likely that the genesis of living matter occurred when the general temperature of the earth was very different from what it is in the present day ; and in order to engage in a profitable course of experimenta- tion, we must first seek to determine, and then to reproduce if possible, all the requisite conditions associated with that general difference in temperature. Whether this can be done, still remains to be seen. That the problem seems' hopeless to-day might have been to Comte a sufficient reason for condemning it as vain and profitless. But the history of stellar astronomy may teach us to beware of thus hastily judging the capacity of the future by that of the present. Till within a few years it would have seemed to the wisest man incredible that we should ever be able to determine the direct approach or recession of a star. Yet, from a quarter least expected, a flood of light has been shed upon this most CH. vin.J THE BEGINNINGS OF LIFE. 437 difficult problem. As the doe, in tlie old fable, keeping her sound eye landward, was at last shot by archers passing in a boat, so Nature has here been forced to render up her secret in the most unlooked-for "way. Through the amazing results obtained by spectrum analysis it has turned out that the heavier difficulty has become the lighter one, and that the direct approach or recession of a star, which affords no parallax, is actually easier to measure than its thwart-motion which affords pai'allax ! In like manner the specific solution of the problem of the origin of life need not be despaired of, nor need we wonder if it come from some quite unsuspected quarter. Meanwhile the considerations above alleged will enable us to put the grand phenomenon of the genesis of life into its proper place among the phenomena of telluric evolution. The gulf between the geologic phase of the process and the biologic phase is so far bridged for us that we may approach the study of the latter without misgivings. In the following chapter I shall enumerate the reasons which compel us to accept the doctrine of the derivation of the more complex forms of life from less complex forms; and because of the interest which just now attaches to the question, I shall make more explicit mention of the opposing doctrine of special creations than its own merits would otherwise justify. CHAPTEE IX. SPECIAL-CEEATION or DERIVATION ? Whatever may be said in condemnation or approval of the method of estimating the worth of men and women by an inquiry into their pedigrees, it cannot be denied that there 'is often much value in such a method of estimating the worth of current ideas. Obviously a theory which was framed in a barbarous age, when men were alike unfamiliar with the con- ceptions of physical causation and uniformity of law and ignorant of the requirements of a valid scientific hypothesis, and which has survived until the present day, not because it has been uniformly verified by observation or deduction, but because it has been artificially jirotected from critical scrutiny by incorporation with a system of theological dogmas assumed to be infallible, — obviously such a theory is at the outset discredited by its pedigree. A presumption is at once raised against it, which a critical examination may indeed do away with, but which for the moment cannot fail to have some weight with a jury of inquirers familiar with the history of human thinking. On the other hand a theory is a priori accredited by its pedigree when it is framed in a cultivated age by thinkers familiar alike with the special phenomena which form its subject-matter and with the requirements of scientific hypothesis in general ; and when, in spite of CH. IS.] SPECIAL-CREATION OR DERIVATION ? 439 theological or sentimeutal prejudice, it so thrives under the most rigorous critical scrutiny that each successive decade enlists in its support a greater and greater number of the most competent investigators of nature. I do not say that such an a pr'iori presumption should ever be taken as decisive in favour of any hypothesis. I say only that such considera- tions do have their weight, and ought to have their weight, in determining the general state of mind which we bring to the discussion of the relative merits of two theories so different in their pedigrees as are the two theories which we are now about to examine. If, with my eyes closed upon all the significant facts which bear i^pon the question of the origin of species, I were required to decide between two hypotheses, of which the one was framed in an age v/hen the sky was supposed to be the solid floor of a celestial ocean, while the other was framed in an age when Lagrange and Laplace were determining the conditions of equilibrium of the solar system, I should at once decide, on general principles, in favour of the latter. And on general principles I should be quite justified in so deciding. Happily, however, we are not called upon to render a decision, upon this or upon any other scientific question, with our eyes shut. In the present chapter we have to examine two opposing hypotheses relating to the origination of the multitudinous complex forms of animal and vegetal life which surround us. And of these two opposing hypotheses we shall find it not difficult to show that the one is discredited, not only by its pedigree and not only by the impossible assumptions which it would require us to make, but also by every jot and tittle of the scientific evidence, so far as known, which bears upon the subject ; while the other, is not only accredited by its pedigree, and by its requiring us to make no impracticable assumptions, but is also corroborated by all the testimony which the patient interrogation of the facts of nature has succeeded in eliciting. The former hypo- 440 COSMIC PHILOSOPHY. [pt. ii. thesis, origiuatiiig in the crude mythological conceptions of the ancient Hebrews, and uncritically accepted until the time of Lamarck and Goethe, in deference to a tradition which invested these mythological conceptions with a peculiar and unwarranted sacredness, is known as the Doctrine of Special Creations. The latter hypothesis, originating in the methodical study of the phenomena of organic life, held by a large number of biologists during the first half of the present century, and of late years accepted by nearly all, may be called the Doctrine of Derivation. In describing the special-creation hypothesis, we are con- fronted by an initial difficulty, due to the enormous change which has occurred in men's habits of thinking since the mythopojic age when it first gained currency. The Hebrew writer, indeed, presents us with a concrete picture of the creation of man, according to which a homogeneous clay model of the human form is, in some inconceivable way, at once transmuted into the wonderfully heterogeneous combina- tion of organs and tissues, with all their definite and highly specialized aptitudes, of which actually living man is made up. But I suppose there are few scientific writers at the present day who would be found willing to risk their reputa- tion for common-sense by attempting to defend such a con- ception. The few naturalists who still make a show of upholding the special-creation hypothesis, are very careful to refrain from anything like a specification of the physical processes which that hypothesis may be supposed to imply. When overtly challenged, they find it safest to shrink from the direct encounter, taking refuge in grandiloquent phrases about " Creative Will " and the " free action of an Intelligent Power," very much as the cuttle-fish extricates itself from a disagreeable predicament by hiding in a shower of its own ink. But, however commendable such phrases may be when regarded as a general confession of faith, they are much worse than useless when employed as substitutes for a CH. IX.] SPECIAL-CREATION OR DERIVATION? 441 scientific description of facts. They only serve to encourage that besetting sin of human thinking, which accepts a play upon words as an equivalent for a legitimate juxtaposition of valid conceptions. When translated, however, from the dialect of mythology into the dialect of science, the special-creation hypothesis asserts that the untold millions of organic molecules of which an adult mammal is ■ composed all rushed together at some appointed instant from divers quarters of the compass, and, spontaneously or in virtue of some inexplicable divine sorcery, grouped themselves into the form of an adult organism, some of them arranging themselves into infinitely complicated nerve-fibres and ganglionic cells, others into the wonderfully complex contractile tissue of muscles, while others again were massed in divers convoluted shapes, as lungs, intestines, blood-vessels, and secreting glands. Or, if a different form of statement be preferred, at one moment we have a background of landscape, with its water and its trees, its sands and its herbage, and at the next succeeding moment we have in the foreground an ox or a man, or, according to another view, a herd of oxen and a group of men, and all this without any assignable group of physical antecedents intervening ! He who can believe that St. Goar, of Treves, transformed a sunbeam into a hat-peg, or that men were once changed into werewolves by putting on an en- chanted girdle, or that Joshua and Cardinal Ximenes con- strained the earth to pause in its rotation, will probably find no difficulty in accepting such a hypothesis to account for the origin of men and oxen. To persons in such a stage of culture it is no obstacle to any hypothesis that it involves an assumption as to divine interposition which is incapable of scientific investigation and uninterpretable in terms of human experience. It can hardly be denied, however, that any hypothesis which involves such an assumption is at once excluded from the pale of science, and relegated to the 442 COSMIC PHILOSOPHY. [pt. ii. regions of mythology, where it may continue to satisfy those to whom mythologic interpretations of natural phenomena still seem admissible, but can hardly be deemed of much account by the scientific inquirer. On the other hand, according to the doctrine of derivation, the more complex plants and animals are the slowly modified descendants of less complex plants and animals, and these in turn were the slowly modified descendants of still less com- plex plants and animals, and so on until we converge to those primitive organisms which are not definable either as animal or as vegetal, but which in their lowest forms are mere shreds of jelly- like protoplasm, such as the spontaneous combination of colloidal clusters of organic molecules might well be capable of originating under appropriate conditions, after the manner pointed out in the preceding chapter. The agencies by which this slow derivation of higher from lower forms has been effected are agencies such as are daily seen in opera- tion about us ; namely, individual variation, adaptation to environing circumstances, and hereditary transmission of in- dividual peculiarities. Obviously such a hypothesis is not only highly credible in itself, since it only alleges that the growth of a complex organism from a simple globule of protoplasm, which is accomplished in every case of individual evolution, has also been accomplished during the evolution of an immensely long series of individuals ; but it is also a purely scientific hypothesis, since it appeals to no agencies save such as are known to be in operation, and involves no assumptions which cannot, sooner or later, be subjected to a crucial test. These preliminary considerations show how strong is the legitimate presumption in favour of the theory of derivation. But the case is not to be dismissed upon these summary, though forcible, considerations. To the general reasons here assigned for preferring the theory of derivation to the theory of special creations, a scientific survey of the phenomena CH. IX.] SFECIAL-CBEATION OR DERIVATION? 443 will add a number of special reasons. Four kinds of argu- ments in favour of the hypothesis of derivation are furnished respectively by the Classification of plants and animals, by their Embryology, by their Morphology, and by their Distri- bution in space and time. I shall devote the present chapter to the consideration of these four classes of arguments; reserving for the following chapter the explanation of the agencies which have been at work in forwarding the process of development. I. The facts which are epitomized in tabular classifications of animals and plants, are so familiar to us that we seldom stop to reflect upon their true significance. And in any bald statement of them which might here be made, the impression of triteness would perhaps be so strong as to prevent that significance from being duly realized, save by the student of natural history. To present in the strongest light the evi- dentiary value of these facts, I shall therefore have recourse to an analogous series of facts in a quite distinct science, where the significance of the classification is illustrated by the known history of the phenomena which are classified. Like the sciences of zoology and botany, the science of philology is pre-eminently a classificatory science, using the method of comparison as its chief implement of inductive research. And philology, at least so far as the study of the Aryan languages is concerned, has been carried to such a high degree of scientific perfection, as regards the accuracy of its processes and the certainty of its results, that we may safely gather from it such illustrations as suit our present purpose. The various Aryan or Indo-European languages are demon- strably descended from a single ancestral language, in the same sense in which the various modern Eomanic languages are all descended from the vulgar Latin of the Western Em- pire. By slow dialectic variations in pronunciation, and in the use of syntactical devices for building up sentences, these languages have been imperceptibly differentiated from a single 444 COSMIC PHILOSOPHY. [pt. ii. primeval language, until they are now so unlike that not one of them is intelligible, save after careful study, to the speakers of another. The minute variations of which the cumulative result is this manifold unlikeness, have not pro- ceeded at haphazard; but they have all along been deter- mined by certain phonetic conditions, which have been so thoroughly generalized, that philologists can now occasionally reconstruct extinct words, after a fashion somewhat similar to that in which Prof. Huxley would, I presume, reconstruct an extinct animal upon seeing one of its fossilized bones or teeth. But what now chiefly concerns us is the fact that all existing Aryan languages are the modified descendants of a common progenitor. Bearing this in mind, let us note sundry features of the classification of these languages. In the first place, it is impossible to arrange them in any linear series which will truly represent their relations to, each, other. In some respects Sanskrit is nearest the original type, in other respects it is Lithuanian which shows the least departure, in other respects it is Old Irish, and in yet others it is Latin. Even if we decide to make a compromise, and to begin with Sanskrit, as being on the whole the least modified of these languages, we cannot stir many steps without getting into diificulties. Suppose we say Sanskrit, Lithuanian, Old Irish, Latin, Old Slavic, Zend, Greek, Gothic, Old German. See now what we have been doing ! We have indeed got Old Irish and Latin close together, as they ought to be, and we have done right in putting Gothic and Old German side by side ; but we have been obliged to thrust in half a dozen languages between Sanskrit and Zend, and between Latin and Greek there is a similar unseemly divoi-ce. When we come to take in the later dialects, the confusion becomes still more hopeless. If after Sanskrit we put in Prakrit and Pali, Urdu and Bengali, and a dozen other derivatives, we must then jump back to Latin, for instance, and after following en. IX.] SPECIAL-CREATION OR DERIVATION? 445 along through Italian, Spanish, French, a.nd their sister-dia- lects, jump back again to some ancient language. Obviously this is violating all the requirements of proper classification, which consists in putting nearest together those objects which are nearest alike. In view of these and other kindred difficulties, philologists have long since agreed to arrange the Aryan family of lan- guages in divergent and re-divergent groups and sub-groups, along lines which ramify like the branches, branchlets, and twigs of a tree. Let us trace the pedigree of the French and English languages, according to this principle of classifica- tion as elaborated by Schleicher, remembering that while other philologists have objected to some of the details of the classification,! all agree, and must agree, in the fundamental principle. Starting, then, from the Aryan mother-tongue, we first encounter two diverging lines of development, re- presented by two extinct phases of language which we may call the South Aryan and North Aryan. Following the pro- gress of the South Aryan, we find it diverging on the one hand into Indo-Iranian, and on the other hand into the parental form of the Hellenic, Italic, and Keltic languages. Neglecting the other branches, and following only the Italic, we find the divergent forms of this exemplified in Umbrian, Oscan, and Latin ; and again, following the career only of the latter branch, we arrive at French and its kindred Eomanic dialects. On the other hand, as we follow the North Aryan line, we find it first dividing into Teutonic and Slavo-Lettish. Neglecting the latter, we observe the Teutonic again diverg- ing into Gothic, Old Norse, and Old German. Following only the latter of these, we may observe it bifurcating into High and Low German, from the latter of which is derived the English which we speak. ' Indeed it is possible that the primary division should be into Eastern and Western, or European and Asiatic, rather than Northern and Southern Aryan. But the future decision of this question will not alter the principle upon which the classification is founded and which it is here cited to exemplify. 446 COSMIC PHILOSOPHY. [pt. ii. Now if we take a general survey of this family-tree, we find that kindred words in languages down near the trunk resemble each other closely, while kindred words in languages high up on the twigs have often well-nigh lost all traces of their primitive family-likeness. To be sure we can still recognize the English daughter in the Sanskrit duliitr, but such strong resemblances are not usual, and it is only too easy to look at a page of Sanskrit without realizing its kinship with English. But to show how the likeness diminishes as we recede from the original source, let us consider two English words — one of which has come to us by natural descent, through the North Aryan line, while the other has come to us, by adoption, from the South Aryan stock. No two words could well be more unlike than the words pen and feather. Of these the latter is a purely English word, while the former is a word we have adopted from the Latin. Now great as is the difference between these two words, it very nearly disappears when we have recourse to their Old Aryan prototypes pata-tra and pat-na. Pat is a word designating flight. Pata-tra and pat-na are words designating a wing, or instrument used in flying. In the course of the North Aryan d,e- y&lo^m&'n.t p)ata-tr a 'becomes fath-thra and finally /ea;!Ae?', just as pa.tar becomes father, in accordance with a general tendency of the Teutonic toward aspirating the hard mutes of the old language ; while on the other hand, in the course of the South Aryan development jja^wa became first joes-ma and t\ienpen-na, in accordance with a general tendency of the Latin toward the assimilation of contiguous consonants. Who but a linguist, knowing the ^istory of the words, and familiar with the general principles of phonetic change, would suspect that words apparently so distinct as pen and feather could be re- ferred so nearly to a common origin ? Or consider the French larme and the English tear. These words are demonstrably descended from the same ancestral form dakru-ma. But while the South Aryan form has undergone one kind of CH. ix.l 8FECIAL-GREATI0N OB DERIVATION? 447 change into the Latin lacru-ma, and thence into the French larme ; the North Aryan form has undergone another kind of change into the Old German tagr, and thence into the English tear. Thus in general, as we go backward in time, we find the lines of linguistic development drawing together. Between the various Low-Dutch dialects spoken along the north coast of Germany, the differences are hardly great enough to inter- fere with mutual intelligibility. Again, between Portuguese and Spanish the differences are so small that one who is well acquainted with Spanish can often get the sense of many pages in a Portuguese book without having specially studied the latter language. But German and Spanish have few mutually intelligible words in common, and their differences iu idioms and in structure of sentences are no less con- spicuous. AVhile it might be possible to maintain that Dutch and Platt-Deutsch, or that Portuguese and Spanish, are only dialects of the same language, no one would hesitate about call- ing Teutonic and Eomance quite different forms of language. Yet we need only go back far enough to find the demar- cation quite as obscure in the one case as in the other ; for Teutonic and Eomance began as the northern and southern dialects of the same Old Aryan language. In similar wise we may say that, even with the keenest linguistic instinct, it would be difficult to decipher a line of modern Persian by reason of its kinship with modern Greek ; while yet it is undeniable that the Persian spoken by the officers of Xerxes was strikingly similar to the Greek spoken by Demaratos and Leonidas. In citing this example from the phenomena of language, I do not cite it as direct testimony in favour of the theory of derivation in biology. Because tear and larvie can be traced back to a common form, it does not foUow that the pig and the horse have a common ancestor. Yet, while the linguistic parallel is by no means available as direct testimony in a 418 COSMIC PHILOSOPHY. [pt. ii. biological question, it lias nevertheless a logical value so im- portant that zoologists as eminent as Haeckel and philologists as profound as Schleicher have not failed to insist upon it. What we see exemplified in these linguistic phenomena, is the ivay in which a classification must he framed in all cases where we have to express complex genetic relationships. We see that where a multitude of objects are associated by a common genesis, we cannot classify them in a linear series, but only in groups and sub-groups, diverging from a common trunk, like the branches and twigs of what we very aptly term a " family-tree." And on the general principles of hereditary relationship, we see that objects near the common trunk will depart less widely from the primitive ancestral type, and will therefore resemble each other more closely, than objects far up on the ends of the branches. A com- parison of the different races of Aryan men would bring out the same results as the comparison of their languages. After making all allowances for the intermixture of the Aryans with divers aboriginal races in Europe and Asia, it remains generally admitted that every Aryan language is spoken by men who are predominantly Aryan in blood. Now it would be impossible to arrange Hindus, Greeks, Italians, Eussians, Germans, and English, in any linear series. We can only divide and subdivide, arranging them in groups that diverge and re-diverge. Such must always be the case when we have to deal with phenomena due to hereditary relationship ; and wherever we find a set of objects thus arranged in groups within groups, converging at the bottom and diverging at the top, we have the very strongest possible primd facie ground for asserting hereditary relationship. Coming now to our main thesis, we can begin to appreciate the strength of the evidence in favour of the derivation- theory, which is furnished by the classification of animals, as effected by Cuvier and Von Baer, and still further elaborated by Huxley and Haeckel. Previous to Cuvier, many eminent CH. IX.] aPEGIAL-CREATION, OR DERIVATION? 449 naturalists endeavoured to arrange the animal kingdom in a series of lineally ascending groups. The illustrious Lamarck - did so ; and the result was that he placed oysters and snails higher up than bees and butterflies. Blainville did better, having come as near as possible to surmounting insurmount- able obstacles; but he nevertheless is forced to put cirrhipeds and myriapoda above the cuttle-fish. It was a great step in advance when Cuvier showed that there are at least four distinct types of animal striicture, and that no linear series can be framed ; although Prof. Agassiz undoubtedly trans- gressed the limits of scientific inquiry, when he attempted to explain the coexistence of these distinct types by resusci- tating from its moss-covered tomb the Platonic theory of Ideas, and impressing it into the service of natural theology. Nevertheless in his remarkable " Essay on Classification," Prof. Agassiz more than atones for these metaphysical aberra- tions by the conclusiveness with which he shows the impossi- bility of making a linear classification of animals. In such a series, the lowest of vertebrates, the unintelligent amphioxus would rank above the wonderfully-organized crabs, ants, and butterflies. The degraded lepidosiren would take precedence of the salmon ; and the lowly-organized duck-bill, as being a mammal, would be placed above the parrot and the falcon. Or if we attempted to escape these difficulties by ranking our animals in a series according to their general complexity of organization, neglecting their typical difi'erences of struc- ture, our whole classification would be thrown into senseless confusion. Parrots and honey-bees would be thrust in among mammals, and not only classes, but even orders, and perhaps families, of annulosa would have to be divided, to make room for intrusive echinoderms and moUusks. In view of these difficulties, as Prof Huxley and Prof. Haeckel have shown, the only feasible manner of arranging the animal kingdom is in a number of diverging or branching lines, like the boughs and twigs of a tree. Starting from the VOL. I. G G 450 COSMW PHILOSOPHY. [pt. ii. amaeba and its kindred, which are neither animal nor vegetal in character, we encounter two diverging lines of develop- ment represented respectively — according to Haeckel's sur- mise — by those protists with harder envelopes which are the predecessors of the vegetable kingdom, and those protists with softer envelopes which are the forerunners of the more mobile animal type of organization.^ Confining our attention to animals, we meet first with the coelenterata, including sponges, corals, and medusae, characterized by the union of masses of amoeba-like units, with but little specialization of structure or of function. Beside these lowly forms, but not immediately above any one of them, we find echinoderms starting off in one direction, worms or annuloida in a second, and moUuscoida in a third. Following the first road, we stop short with echinoderms. But on the second, we find annuloid worms succeeded by articulata, or true annulosa, which re-diverge in sundry directions, reaching the greatest divergence from the primitive forms in the crabs, spiders, and ants. On the third road, we find the moUuscoid worms diverging into mollusks and vertebrates. On the one hand, through the bryozoa we are gradually led to the true moUusks, while on the other hand the tunicata, of which the ascidian or " pitcher " (the primitive " tadpole " of unscientific ridi- culers of Darwinism) is the most familiar form, lead us directly to the vertebrates.^ At first the vertebrata are all ' Though I leave this sentence as it was written three years ago, it must not be understood as an unq^ualified endorsement of Prof. Haeckel's attempt to erect a third kingdom — of Protists— comprising such organisms as are neither distinctively animal nor vegetable. There is something to be said in behalf of such an arrangement, provided no attempt be made to draw a hard and fast line between the protistic and the two higher kingdoms ; and I sup- pose that no follower of Haeckel is likely to make such an attempt. Since a bacterium or a vibrio is clearly not an animal, and clearly not a vegetable, while it is clearly a living thing, there would seem to be some convenience in having a region to which to assign it. I should, however, regard this "region" of protists, or lowest organisms, as not strictly a "kingdom," but rather as the indefinite border-land between the animal and vegetal worlds on the one hand and the realm of inorganic existence on the other. 2 Kowalewsky has discovered some wonderful likenesses between the em- bryonic development of the ascidian and that of the amphioxus or lowest CH. IX.] SPECIAL-CREATION, OR DERIVATION 7 451 fishes, if such moUusk-like creatures as the amphioxus can strictly be included among fishes ; but presently here too the lines begin to diverge, and we encounter reptiles and birds on the one hand, and mammals on the other, all three being related to fishes through the remarkable structures of living and extinct batrachia. Such, as stated with crude brevity, is the classification of animals most in accordance with our present knowledge. Now from first to last, the farther we trace any one line of development, the more widely we find it diverging from other lines which originated in the same point. The higher insects and crustaceans are not at all like worms ; but the myriapoda, the lower crustaceans, and the caterpillars of higher insects, are like worms. Viewed at the upper ends of the scale, the moUusks are widely different from the vertebrates : viewed at the lower end, the difference almost vanishes — the amphioxus being closely similar in structure to the ascidians, whose embryos present rudiments of a vertebral column. No two animals could well be more strikingly unlike than a wren and an elephant; yet the lowest known mammal, the known vertebrate. Of all the "missing links,'' the assumed absence of which is so persistently cited by the adherents of the dogma of fixity of species, the most important one would here appear to have been found ; for it is a link which connects the complex and highly-evolved vertebrate with a very lowly form which passes its natural existence rooted plant-like to the soil, or rather to the sea-bottom. The ascidian cannot, indeed, be regarded as typifying the direct ancestors of the vertebi-ata. It is a curiously aberrant and degraded form, and its own progenitors had doubtless once " seen better days." In its embryonic state it possesses a well-marked vertebral column, and it behaves in general very much as if it were going to grow to something like the amphioxus. But it afterwards falls considerably short of this mark. Already in early life its vertebrae begin to become "rudimentary" or evanes- cent ; and when fully matured, it stops swimming about after its prey, and, striking root in the sub-marine soil, remains thereafter standing, with its broad pitcher-like mouth ever in readiness to suck down such organisms floating by as may serve for its nutriment. That vertebrae should be found in the embryo of such an animal is a most interesting and striking fact. It would seem to mark the ascidian as a retrograded ofi'shoot of those primitive forms on the way toward assuming the vertebrate structure, of which the more fortunate ones succeeded in leaving as their representative the am- phioxus. . G G 2 452 COSMIC PHILOSOPHY. [ft. ii. Australian duck-bill, possesses many bird-like characteristics. In the man and the oak, we get perhaps the widest possible amount of divergence between organisms ; yet at the bottom of the animal and vegetal kingdoms, we find creatures like the amojba and protococcus, which cannot be classified as either animal or vegetal, because they are as much one as the other. Moreover, as we go back in time, we find the lines of development, now so widely distant from each other, con- tinually drawing together. As a general rule, extinct animals are less specialized than surviving animals ; and the same is true of plants. The ancient animal departed less widely from the general type of the class or sub-kingdom to which he belonged than the modern animal. The monotremata, which of all mammals are the least remote from reptiles and birds, are at the same time the oldest. In the teleosts or true fishes the differential characteristics of the vertebrate type are more strongly pronounced than in the older selachians, to which order belongs the shark. Far back, in secondary times, we find lizards strongly resembling fishes, and other saurian creatures which differ little from birds. Confining our attention to any particular group, such as that which embraces the ruminants and pachyderms, we find the hipparion of the Eocene epoch less specialized than either of his later kindred, the horse, ass, zebra, and quagga ; while the gap between such dissimilar animals as the pig and the camel is to a great extent filled by transitional forms found in various tertiary strata. Again, it hardly needs stating that, as we proceed from a general survey of any group of animals or plants to a survey of the sub-groups of which it is made up, we find the differences constantly growing less numerous and less funda- mental. The differences between the ox and the lion are many and important ; but between the various members of the order carnivora, between the lion and the wolf or the CH. ix.J SPECIAL-CREATION, OB DEIUVATION? 453 bear, the differences are less. As we descend another step, and compare lions with lynxes, jaguars, leopards and cats, which belong to the same family, we find the points of divergence fewer and less characteristic. Between wild and domestic cats there is still less difference ; while between the various breeds of the domestic cat the distinctions are limited to superficial characteristics of size, colour, and general intelligence. Hence, in classifying contemporary organisms of high development, naturalists are never in doubt as to the class, or order, and but seldom as to the family ; while they are not unfrequently in doubt as to the genus, and are con- tinually disputing as to the species or variety to which a given form belongs. As we descend in the scale of develop- ment, and go back in geologic time, the determination of genera becomes more and more difficult. Doubts frequently arise with reference to family, order, and class. And at last even the sub-kingdom becomes doubtful, as is strikingly shown by the difficulty in classifying the lowly animals provisionally grouped by Cuvier as radiata, when contrasted with the ease with which naturalists distinguish the higher sub-kingdoms. Now all this complex arrangement of organisms in groups within groups, resembling each other at the bottom of the scale and differing most widely at the top, is just the arrange- ment which, as we have seen, must result from genetic relationship ; and upon any- other theory than that of deriva- tion it is utterly inexpKcable. If each species has been separately created, no reason can be assigned for such an arrangement, — unless perchance someone can be found hardy enough to maintain that it was intended as a snare and a delusion for human intelligence. The old opponents of geology, who strove to maintain at whatever cost the scientific credit of the Mosaic myth of the creation, asserted that fossil plants and animals were created already dead and petrified, just for the fun of the thing. Manifestly 454 COSMIC PHILOSOPHY. [pt. ir. those persons take a quite similar position, who pretend that God created separately the horse, ass, zebra, and quagga, having previously created a beast enough like all of them to be their common grandfather. Indeed, so powerful is this argument from classification that it has always seemed to me sufficient by itself to decide the case in favour of the theory of derivation. In my own case, the facts presented in Prof. Agassiz's " Essay on Classification " went far toward producing conviction before the publication of Mr. Darwin's work on the " Origin of Species," where the significance of such facts is clearly pointed out and strongly insisted upon. II. An equally powerful argument is furnished by the embryonic development of organisms. As Von Baer long ago pointed out, the germs of all animals are at the outset exactly like each other ; but in the process of development each germ acquires first the differential characteristics of the sub-kingdom to which it belongs, then successively the characteristics of its class, order, family, genus, species, and race. For example the germ-cell of a man is not only in- distinguishable from the germ-cell of a dog, a chicken, or a tortoise, but it is like the adult form of an amceba or a protococcus, which are nothing but simple cells. Four weeks after conception, the embryos of the man and the dog can hardly be distinguished from each other, but have become perceptibly different from the corresponding embryos of the chicken and tortoise. At eight weeks a few points of differ- erence between the dog and the man become perceptible; the tail is shorter in the human embryo, and the cerebrum and cerebellum have become larger, relatively to the corpora quadrigemina, than in the embryo of the dog; but these differences are less striking than those which separate the two mammals on the one hand from the reptile and bird on the other. At a later stage the human embryo becomes still more unlike that of the dog, acquiring characteristics peculiar to the order of primates to which man belongs. CH. ii.j SPECIAL-CREATION, OR DERIVATION ? 455 Lastly the foetus of civilized man, at seven months, is entirely human in appearance, but stiU has not thoroughly acquired the physical attributes which distinguish the civilized man from the Australian or the negro. On the evolution-theory these phenomena are explicable as due to the integration or summing-up of adaptive pro- cesses, by which modifications slowly acquired through gene- rations of ancestral organisms are more and more rapidly repeated in the embryos. Hence, as Prof. Haeckel has elaborately proved, we must expect to find the phenomena of embryology in complete harmony with the facts of the geological succession of organisms. Observation shows that the harmony is complete ; and again, unless we are to suppose that the phenomena of nature have been maliciously arranged with the express purpose of cheating us, we have no choice but to accept that harmony as proof of the truth of the evolution-theory. Kindred evidence is furnished by the well-known fact that many animals, during their fcetal life, acquire organs like those possessed by adults of allied species, but which, having no functions to discharge, are after awhile absorbed or dwindle into mere rudiments. The mammalian embryo at first circulates its blood through a vascular system like the gills of fishes ; afterwards this is replaced by a vascular mem- brane called the allantois, like the membrane which replaces gills in the development of birds and reptiles. Neither of these structures is useful to the embryo for the pui-pose of aerating its blood, and there is no possible explanation of their appearance in untold mUIions of mammals, unless we admit that they are due to inheritance from the amphibious ancestors of the mammalian class. Of like meaning are such facts as the presence of useless teeth in the jaws of foetal whales, and in the beaks of certain embryonic birds ; the rudiments of a pelvis and hind-limbs in many snakes ; the wings, firmly fastened under their wing-cases, in insects 458 COSMIC PHILOSOPHY. [vc. u. gill-like slits on each side of the ueck, up to which the arteries run in arching branches, as in a fish ; the heart is at first a simple pulsating chamber, like the heart of the lowest fishes ; at a later period there is a movable tail considerably- longer than the legs ; the great toe projects sideways from the foot, like the toes of adult monkeys and apes ; and, during the sixth month, the whole body is covered very thickly with hair, extending even over the face and ears, everywhere, indeed, save on the lower sides of the hands and feet, which are also bare in the adult forms of other mammals. In like manner, the tadpole of the black salamander, which is not born until it is fully formed, and which never swims, never- theless has gills as elaborately feathered as those which, in the tadpoles of other salamanders, are destined for use. Treatises on embryology are crowded with just such facts as these. Now why is it that, in all cases, before a complex organism "can attain the structure which distinguishes it, there must be an evolution of forms which distinguish the structures of organisms lower in the series"? "None of these phases have any adaptation to the future state of the animal ; many of them have no adaptation even to its em- bryonic state." On the hypothesis that each species of organisms was independently built up by a Divine Architect, how are we to explain these circuitous proceedings .' " What," asks Mr. Lewes, " should we say to an architect who was unable, or being able was obstinately unwilling, to erect a palace except by first using his materials in the shape of a hut, then pulling it down and rebuilding them as a cottage, then adding storey to storey and room to room, not with any reference to the ultimate purposes of the palace, but wholly with reference to the way in which houses were constructed in ancient times ? What should we say to the architect who could not directly form a museum out of bricks and mortar, but was forced to begin as if going to build a mansion ; and after proceeding some way in this direction, altered his plan CH. IX.] SPEGIAL-GUEATION, OB DERIVATION'? 459 into a palace and that again into a museum ? Yet this is the sort of succession on which organisms are constructed." It is out of this very uncomfortable corner that metaphysical naturalists have sometimes attempted to slip, by gravely asserting that Nature is obliged to work tentatively ! Thus we see that the habit of personifying Nature may sometimes be made to serve an argumentative purpose. When theo- logians are molested by uncomfortable questions concerning the existence of phenomena which seem incompatible with the perfect wisdom of an anthropomorphic Deity, they are wont to ascribe them to the Devil. It must be acknowledged that metaphysical naturalists practise a more graceful, though not a more candid, method of evasion, when they erect Nature (spelled with a capital) into a person distinct from phenomena, and coolly ascribe to her the shortcomings which they dare not lay to the account of a personal Deity. Viewed in the light of a scientific logic, this argument from embryology, like the argument from classification, seems powerful enough, when taken alone, to decide the case in favour of the derivation theory. As already hinted, these phenomena are in general explicable by the Doctrine of Evolution. But to the special-creation hypothesis they are unmanageable stumbling-blocks. Even without any profound knowledge of embryology, one may readily see that if the tadpoles of the black salamander were anciently born as tad- poles, and swam in the water, they may still retain their ex- quisite gills while nourished to a later stage of development in the maternal organism. But on the opposite theory the existence of these gills is meaningless. III. The equally significant facts of morphology may be more concisely presented. Why, unless through common in- heritance, should all the vertebrata be constructed on the same type ? Structurally considered, man, elephant, mouse, ostrich, humming-bird, tortoise, snake, frog, crocodile, halibut, herring, and shark, are but different modifications of one common 460 COSMIC PHILOSOPHY. [pt. ii. form. It is a familiar fact that the arms of men and apes, the fore-legs of quadrupeds, the paddles of cetacea, the wings of birds, and the breast-fins of fishes are structurally identical, being developed from the same embryonal rudiments. Ex- ternally there is but little resemblance between the human hand and the hoof of a horse ; yet anatomy shows that the horse's hoof is made up of claws or fingers firmly soldered together. Turning to the annulosa, we find that all insects and crustaceans — dragon-flies and mosquitoes as well as crabs and shrimps — are composed of just twenty segments. " What now," asks Mr. Spencer, " can be the meaning of this com- munity of structure among these hundreds of thousands of species filling the air, burrowing in the earth, swimming in the water, creeping about among the sea-weed, and having such enormous differences of size, outline and substance, that no community would be suspected between them ? Why, under the down-covered body of the moth and under the hard wing-cases of the beetle, should there be discovered the same number of divisions as in the calcareous framework of the lobster?" But two answers are possible. We may either say, with the Mussulman, "it so pleased Allah, whose name be exalted ; " or we may honestly acknowledge the scientific im- plication that such community of structure is strong evidence in favour of community of origin. IV. The facts of geographical distribution and geological succession are likewise in complete harmony with the develop- ment theory. On the hypothesis of special creations, no good reason can be given why the extinct animals found in any geographical area should resemble, both in general structure and in special modifications, the animals which now live in the same area. Thus the fossil mammals of Australia are chiefly marsupials, allied in structure to the marsupials which now inhabit that continent ; the extinct mammals of South America closely resemble living sloths, armadillos and ant- eaters. " I was so much impressed with these facts," says OH. IX.] SPECIAL-CREATION, OR DERIVATION'? 461 Mr. Darwin, "that T strongly insisted, in 1839 and 1845, on this wonderful relationship in the same continent between the dead and the living. Prof. Owen has subsequently ex- tended the same generalization to the mammals of the Old World. We see the same law in this author's restorations of the extinct and gigantic birds of New Zealand. We see it also in the birds of the caves of Brazil. Mr. Woodward has shown that the same law holds good with sea-sheUs. Other cases could be added, as the relation between the extinct and living land-shells of Madeira ; and between the extinct and living brackish-water shells of the Aralo-Caspian Sea." It has indeed been urged, by upholders of the special- creation hypothesis, that these striking resemblances may be explained by supposing each species to have been created in strict adaptation to the conditions of life surrounding it. That is to say, God has continued to create edentata in South America and marsupials in Australia, because these two continents are best fitted for the comfortable main- tenance respectively of edentata and of marsupials. Stubborn facts, however, are opposed to this theory of the methods of Divine working. The assumption that each species is best adapted to its own habitat is refuted by such facts as the now rapidly progressing extermination of native animals and plants in Kew Zealand by European organisms lately carried there. Cow-grass, thistles, dock, and white clover flourish more vigorously in New Zealand than in England, and within a few years have almost displaced the native grasses ; while the native rats and flies are fast dis- appearing before the rats and flies imported from Europe. The assumption is still more strikinglyrefuted by a comparison of the forms of life which inhabit Australia with those which inhabit the southern extremities of Africa and South America. These three tracts of land are very similar in their physical conditions, and yet, as Mr. Darwin has observed, it would be impossible to point out three faunas and floras more 402 COSMIC PHILOSOPHY. [pt. it. strikingly dissimilar. If the distribution of organisms were miraculously determined in accordance with their fitness to their surrounding conditions, the fauna of South America in latitude 35° ought to resemble the fauna of Australia in the same latitude more closely than it resembles the fauna of South America in latitudes north of 25°. The case is just the reverse. Again there is no appreciable difference between the conditions of existence in the seas east and west of the isthmus of Panama ; and, according to the assumption of the special-creationists, their marine faunas ought to be almost exactly alike. In fact no two marine faunas are more completely distinct. Hardly a fish, mol- lusk, or crustacean is common to the eastern and western shores. This is because the isthmus, though narrow, is im- passable for marine organisms. On the other hand, wherever groups of organisms are not prevented by impassable barriers from spreading over wide tracts of country or of sea, we find distinct but closely-allied species widely spread and living among the most diverse conditions. The inference is obvious that the population of different zoological and botanical areas is due to migration, and not to special creation. Where organisms have a chance to migrate, they migrate, and became, adapted, by slight specific changes, to the new cir- cumstances which they encounter. But where there is a barrier between one area and another, there we find complete diversity between the inhabitants of the two areas, although there is no reason for such diversity, save the impossibility of getting across the barrier. Of like meaning is the fact that batrachians and terrestrial mammals are never found indigenous upon oceanic islands. As Mr. Darwin observes, " the general absence of frogs and toads from oceanic islands cannot be accounted for by their physical conditions ; indeed it seems that islands are peculiarly well fitted for these animals ; for frogs have been introduced into Madeira, the Azores, and Mauritius, and have multiplied so as to be- CH. [X.J SPEOIAL-GREATION, OB DERIVATION? 4(i3 come a nuisance. But as these animals and their spawn are known to be immediately killed by sea-water, there would be great difficulty in their transportal across the sea, and therefore on my view we can see why they do not exist on any oceanic island. But why, on the theory of creation, they should not have been created there, it would be very difficult to explain." That terrestrial mammals cannot cross the sea is obvious ; but bats and birds, which can fly, are found on many oceanic islands. In an admirable essay on the migrations of organisms, considered with reference to the Darwinian theory, Prof Moritz Wagner has collected many similar examples. From personal observations in North Africa, in Western Asia, in Hungary, and in America, this veteran naturalist educes the general conclusion that the limits within which allied species are found, are determined by impassable natural barriers. Coleoptera with their wings fastened down under their wing-cases, are specifically dif- ferent on the opposite shores of small rivers ; while butterflies and hymenoptera range over large tracts of inland country, but are stopped by such obstacles as the Straits of Gibraltar. On opposite sides of the Andes, the conditions of existence differ but little, while on the north and south sides of the Caucasus the difference in climate is extreme. Yet the Andes are much the more difficult to cross ; and accordingly the fauna which they separate are much more unlike than the fauna separated by the Caucasus. In like manner the Galapagos Islands, situated some six hundred miles from the South American continent, possess a fauna which, with the exception of a few birds, is generically distinct from all other faunas. Yet though generically distinct, it is South Ameri- can in type, and most resembles the fauna of Chili, the nearest mainland. Furthermore, among the animals living on the different islands of the group, we find specific diversity along with generic identity. So also Madeira "is inhabited by a wonderful number of peculiar land-shells, whereas not 464 COSMIC PHILOSOPB Y. [pt. ii. one species of sea-shell is peculiar to its shores." Similar relations are found universally to hold between the organisms which inhabit oceanic islands and those which inhabit neigh- bouring continents. These facts of geographical distribution, when taken in connection with the facts of geological succession above men- tioned, speak very emphatically in favour of the derivation theory. That theory affords a satisfactory explanation for this entire class of facts, while the special-creation hypothesis is incompetent to explain a single one of them. They are, moreover, in perfect harmony with the prominent facts of morphology, of embryology, and of classification ; so that the evidence furnished by the four classes of facts taken together becomestruly overwhelming. When in the next chapter we come to consider the specu- lations and discoveries of Mr. Darwin, we shall see that the case in favour of derivation is even stronger than as here presented; for we shall see that certain agencies are un- ceasingly at work, with the long continuance of which the absolute stability of specific forms is incompatible. But, as between the two hypotheses of special creation and of deriva- tion, the arguments already brought forward are far more than sufficient for a decisive verdict. The presumption raised- at the outset against the Doctrine of Special Creations is even superfluously confirmed by the testimony of facts. Not only is this doctrine discredited by its barbaric origin, and by the absurd or impossible assumptions which it would require us to make; but it utterly fails to explain a single one of the phenomena of the classification, embryology, morphology, and distribution of extinct and living organisms. While, on the other hand, the Doctrine of Derivation is not only accre- dited by its scientific origin and by its appealing to none b\it verifiable processes and agencies, but it affords an explana- tion for each and all of the above-mentioned phenomena. I think we may, therefore, without further ado, consign ca. IX.] SPECIAL-CREATION, OR DERIVATION ? 465 the special- creation hypothesis to that limbo where hover the ghosts of the slaughtered theories that were born of man's untutored intelligence in early times. There we may let it abide, along with the vagaries of the astrologists, the doctrine of signatures, the archceus of Paracelsus, the elixir vitce of the alchemists, and the theory of perpetual motion. The space which we have here devoted to it is justified by the vividness with which the discussion has brought before us the contrast between mythology and science, between Anthropomorphism and Cosmism. But in the chapters which are to follow, the question of its merits or demerits will no longer concern us. END OF VOL I. VOL. L H H MESSRS. MACMILLAN AND GO.'S PUBLICATIONS. PEOFESSOE HUXLEY'S LAY SEEMONS, ADDEESSES and REVIEWS. New and Cheaper Edition.. Crown 8vo. 7s. 6d. 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