(s \s fa PEOBLEMS LIFE AND MIND fSIXTEO BY BALLAXTVXE AXD CC FD1XBVKGH AKD LONDON Ex Libris C. JL OGDEN PROBLEMS OP LIFE AND MIND THE FOUNDATIONS OF A CREED VOL. L LONDON TRUBNER & CO., LUDGATE HILL 1874 All Rights reserved TJTJRAKY - SANTA BARBARA PREFACE. THE work, of which this is the first volume, has been many years in preparation ; indeed its origin may be said to go so far back as 1836, when with the rashness of ambitious youth I planned a treatise on the Philo- sophy of the Mind in which the doctrines of Reid, Stewart, and Brown were to be physiologically inter- preted. In 1837 I gave a course of lectures on the subject in Fox's Chapel, Finsbury. The scheme was abandoned, partly because of a growing dissatisfaction with the doctrines of the Scotch School, and partly perhaps from a misgiving as to my physiological know- ledge. Other studies and other labours occupied me until 1860, when I believed that my researches into the nervous system had placed in my hands a clue through the labyrinth of mental phenomena ; and misled by the plausible supposition that the complex phenomena in Man might be better interpreted by approaching them through the simpler phenomena in Animals, I began to collect materials for a work on Animal Psychology. This also proved to be premature. Rightly to under- stand the mental condition of Animals we must first gain a clear vision of the fundamental processes in VI PREFACE. Man ; since, obviously, it is only through our know- ledge of the processes in ourselves that we can interpret the manifestations of similar processes in them; and here we are hampered by the anthropomorphic ten- dency which leads us to assign exclusively human mo- tives to animal actions. In 1862 I began the investigation of the physiolo- gical mechanism of Feeling and Thought, and from that time forward have sought assistance in a wide range of research. Anatomy, Physiology, Pathology, Insanity, and the Science of Language, have supplied facts and suggestions to enlarge and direct my own meditations, and to confirm and correct the many valuable indications furnished by previous psychological investigators. Let me not be thought ungrateful to my predecessors, some of whose contributions are of imperishable value, if, while acknowledging the illumi- nation I have received from their labours, I declare my conviction that in spite of all they have achieved Psy- chology is still without the fundamental data necessary to its constitution as a science ; it is very much in the condition of Chemistry before Lavoisier, or of Biology before Bichat. Isolated discoveries, however valuable, do not suffice. A science is constituted that is, has received its definitive construction, and place in the hierarchy of Philosophy, when its object is circum- scribed, its phenomena defined, its Method settled, and its fundamental principles established, so that hencefor- ward the development is progressive, the discovery of to-day enlarging and not overturning the conception of yesterday, each worker bringing his contribution PREFACE. VU to a common fund, not presenting it as a reversal of all that predecessors had done. To note a deficiency is one thing, another to remedy that deficiency. Clearly as the want of fundamental principles appeared to me, I was under no illusion as to my being in possession of the necessary induc- tions; and I therefore only contemplated working at special questions, without reference to their common connections. A varied set of detached investigations had grown into a huge mass of heterogeneous MS. before any central light appeared to shape the chaos into a system. When I began to organise these ma- terials into a book, I only intended it to be a series of essays treating certain problems of Life and Mind. But out of this arose two results, little contemplated. The first result was such a mutual illumination from the various principles arrived at separately that I began to feel confident of having something like a clear vision of the fundamental inductions necessary to the consti- tution of Psychology; hence, although I do not pro- pose to write a complete treatise, I hope to establish a firm groundwork for future labours. The second result, which was independent of the first, arose thus : Finding the exposition obstructed by the existence of unsolved metaphysical problems, and by the too frequent employment of the metaphysical Method, and knowing that there was no chance of gen- eral recognition of the scientific Method and its induc- tions while the rival Method was tolerated, and the conceptions of Force, Cause, Matter, Mind were vacil- lating and contradictory, I imagined that it would be Vlll PREFACE. practicable in an introductory chapter, not indeed to clear the path of these obstacles, but at least to give such precise indications of the principles adopted throughout the exposition as would enable the reader to follow it untroubled by metaphysical difficulties. That intro- ductory chapter has grown insensibly into a substan- tive work ; and the two volumes of which it consists are but a portion of what has been written. Not only has the chapter grown into a work, the work itself has grown into a systematic introduction to the philo- sophy of Science ; and what was intended merely as a preparation for a Psychology, discloses itself as the Foundations of a Creed. This brief sketch of its history may not only explain and partly justify the somewhat ambitious pretensions of this work, it will also explain and partly justify cer- tain defects in its composition. Having grown up heterogeneously, its structure is heterogeneous. Sec- tions now brought together have been wrought out at the distance of years, and without reference to each other ; while during repeated revisions and remodifica- tions many repetitions and cross references have been inserted, and sentences bearing the obvious trace of 1872 or 1873 appear in pages originally written per- haps eight or ten years previously. The reader is also sometimes called upon to accept results for which the evidence can only be produced in subsequent chapters or volumes. I have so far guarded against this evil that in such cases I have only asked for pro vision; il assent. PREFACE. IX The Foundations of a Creed ought to have sufficient standing-room for antagonistic schools. The general consideration that every philosophical opinion must have some truth sustaining it, is here adopted; and therefore due weight is attempted to be assigned to adverse arguments for example, those which affirm and those which deny the possibility of Metaphysics, or the existence of Innate Ideas ; the facts which favour, and the facts which exclude, the spiritualist hypothesis and the materialist hypothesis. While cordially agree- ing with those philosophers who reject both Spiritualism and Materialism, I do not agree with them in their conclusion that we know nothing whatever of Mind or Matter. I hold with their antagonists that we know a great deal of both. I cannot agree that Philosophy gains any refuge from difficulties by invoking the Un- knowable ; though it may admit the existence of the Unknowable, this admission is transcendental, and leaves all the purposes of Philosophy unaffected. Deep- ly as we may feel the mystery of this universe and the limitations of our faculties, the Foundations of a Creed can only rest upon the Known and Knowable. The second volume, completing this First Series, is now under final revision. THE PRIORY, Sept. 1873. CONTENTS. INTEODUCTIOK PART I. THE METHOD OF SCIENCE AND ITS APPLICA- TION TO METAPHYSICS. CHAPTER I. PAGE THE CONFLICT OF OPINION AND THE ISSUE, , . 1 CHAPTER II. THE CONDITIONS STATED, 13 CHAPTER III. THE METHOD, 29 CHAPTER IV. OBJECTIONS TO METAPHYSICS, 61 CHAPTER V. THE PLACE OF METAPHYSICS AMONG THE SCIENCES, . . . 71 PAET II. THE RULES OF PHILOSOPHISING, 88 PSYCHOLOGICAL PRINCIPLES, . . 107 BIOSTATICS, . 115 PSYCHOSTATICS, ....118 THE METHOD OF PSYCHOLOGY, ....... 125 THE BIOLOGICAL DATA, 128 PSYCHODYNAMICS, 134 Xll CONTENTS. PAOK THE PSYCHOLOGICAL SPECTRUM 146 THE SOCIOLOGICAL DATA, . ' 152 REASONED REALISM, ...... 176 PROBLEM I. THE LIMITATIONS OF KNOWLEDGE. CHAPTER I. THE PRINCIPLE OF RELATIVITY, ....... 199 CHAPTER II. THE SENSATIONAL AND A PRIORI HYPOTHESES, .... 207 (Instinct], '...'. 226 CHAPTER III. THE SENSIBLE, THE EXTRA-SENSIBLE, AND THE SUPRA-SENSIBLE, 249 (Tlie Extra-Sensible World), . . . . ' -. . 259 (The Supra-Sensible World], 264 CHAPTER IV. THE REALITY OP ABSTRACTIONS. . 275 (Co-ordination), 279 CHAPTER V. IDEAL CONSTRUCTION IN SCIENCE, 285 (Moral Types), 304 CHAPTER VI. . WHAT ARE LAWS OF NATURE I 307 CHAPTER VII. THE USE AND ABUSE OF HYPOTHESIS, ... . 314 CHAPTER VIII. THE PASSAGE FROM THE ABSTRACT TO THE CONCRETE, . 342 CHAPTER IX. IDEAL CONSTRUCTION IN METAPHYSICS, . . .... 347 CONTENTS. Xlll CHAPTER X. PACK THE SEARCH AFTER CAUSES, 356 (The Ideas of Cause and Substance), . . . 358 (The How and the Why), 362 (The Two Conceptions of Law), 365 CHAPTER XI. INTUITION AND DEMONSTRATION, 368 CHAPTER XII. AXIOMS AND THEIR VALIDITY, 384 CHAPTER XIII. NECESSARY TRUTHS, 390 CHAPTER XIV. MATHEMATICS AN EMPIRICAL SCIENCE, 415 CHAPTER XV. SOME OBSERVATIONS ON KANT, 437 CHAPTER XVI. THE PLACE OF SENTIMENT IN PHILOSOPHY, .... 455 INTBODTJCTION. PART I. THE METHOD OF SCIENCE AND ITS APPLICATION TO METAPHYSICS. PART II. THE RULES OF PHILOSOPHISING. " England's thinkers are again beginning to see, what they had only temporarily forgotten, that the difficulties of Metaphysics lie at the root of all Science ; that those difficulties can only be quieted by being resolved, and that until they are resolved, positively whenever possible, but at any rate negatively, we are never assured that any knowledge, even physical, stands on solid foundations." STUART MILL. " Ich erkiihne mich zu sagen, dass nicht eine einzige metaphysische Aufgabe sein miisse, die hier nicht aufgelost, oder zu deren Auflosung nicht wenigstens der Schlussel dargereicht wordeu." KANT. INTKODUCTION, PART I. THE METHOD OF SCIENCE AND ITS APPLICATION TO METAPHYSICS. CHAPTEK I. THE CONFLICT OF OPINION AND THE ISSUE. 1. No one meditating on the present condition of the intellectual world can fail to be arrested by the evi- dences of its deep-seated unrest. Yeast is working everywhere. Ancient formulas and time-honoured creeds are yielding as much to internal pressure as to external assault. The expansion of knowledge is loosening the very earth clutched by the roots of creeds and churches. Rejoice over this or deplore it, the fact is unmistakable. Sects and parties, in the endeavour to sustain their positions, arid to preserve at least their watchwords and the outward semblance of their creeds, nowadays snatch eagerly at compromises which a few years ago would have been scouted as heresies. Science is pene- trating everywhere, and slowly changing men's concep- tion of the world and of man's destiny. Doctrines which once were damnable are now fashionable, and VOL. I. A 2 PROBLEMS OF LIFE AND MIND. heresies are appropriated as aids to faith. Ours is no longer the age described by Carlyle, " destitute of faith, yet terrified at scepticism." It is an age clamorous for faith, and only dissatisfied with scepticism when scepticism is a resting-place instead of a starting-point, a result instead of a preliminary caution. The purely negative attitude of Unbelief, once regarded as philo- sophical, is now generally understood to be only laudable in the face of the demonstrably incredible. 2. The great desire of this age is for a Doctrine which may serve to condense our knowledge, guide our researches, and shape our lives, so that Conduct may really be the consequence of Belief. We are growing impatient of futile compromises and half-beliefs ; we see that it will not do to believe, or pretend to believe, one theory of the universe, yet show, in every way wherein confidence can show itself, that our lives are ruled by another theory. In consequence of this desire, while thinking men appear, on a superficial view, to be daily separating wider and wider from each other, they are, on a deeper view, seen to be drawing closer together differing in opinion, they are approximating in spirit and purpose. There is a conspicuous effort to reconcile the aims and claims of Religion and Science the two mightiest antagonists. The many and piteous complaints, old as Religion itself, against the growing infidelity of the age, might be disregarded were they not confirmed on all sides by the evidence that Religion is rapidly tending to one of two issues either towards extinction, or towards transformation. Some considerable thinkers regard the former alternative as the probable and de- sirable issue. They argue that Religion has played its SCIENTIFIC METHOD IN METAPHYSICS. 3 part in the evolution of Humanity a noble part, yet only that of a provisional organ, which, in the course of development, must -be displaced by a final organ. Other thinkers and I follow these consider that Ee- ligion will continue to regulate the evolution ; but that to do this in the coming ages, it must occupy a position similar to the one it occupied in the past, and express the highest thought of the time, as that thought widens with the ever-growing experience. It must not attempt to imprison the mind in formulas which no longer contain the whole of positive knowledge. It must not attempt to force on our acceptance, as explana- tions of the universe, dogmas which were originally the childish guesses at truth made by barbarian tribes. It must no longer present a conception of the world and physical laws, or of man and moral laws, which has any other basis than that of scientific induction. It must no longer put forward principles which are unintelligible and incredible, nor make their very un- intelligibility a source of glory, and a belief in them a higher virtue than belief in demonstration. In a word, this transformed Eeligion must cease to accept for its tests and sanctions such tests as would be foolishness in Science, and such sanctions as would be selfishness in Life. Instead of proclaiming the nothingness of this life, the worthlessness of human love, and the imbe- cility of the human mind, it will proclaim the supreme importance of this life, the supreme value of human love, and the grandeur of human intellect. Those who entertain this hope, and this view of a Eeligion founded on Science expressing at each stage what is known of the world and of man, believe and I share the belief that the present antagonism will rapidly 4 PROBLEMS OF LIFE AND MIND. merge in an energetic co-operation. The internecine warfare which has so long disturbed Religion and ob- structed Science, will give place to a Doctrine which will respect the claims of both, and satisfy the needs of both. 3. This future may be undetermined, but it will come. It will not come without contention. The ground will be contested inch by inch. The pathway of Progress will still, as of old, bear traces of martyr- dom; but the advance is inevitable. The signs of the advent are not few. Looking at them with some closeness, one observes that Science itself is also in travail. Assuredly some mighty new birth is at hand. Solid as the ground appears, and fixed as are our present landmarks, we cannot but feel the strange tremors of subterranean agitation which must ere long be followed by upheavals disturbing those landmarks. Not only do we see Physics on the eve of a recon- struction through Molecular Dynamics, we also see Metaphysics strangely agitated, and showing symptoms of a reawakened life. After a long period of neglect and contempt, its problems are once more reasserting their claims. And whatever we may think of those, claims, we have only to reflect on the important part played by Metaphysics in sustaining and developing religious conceptions, no less than in thwarting and misdirecting scientific conceptions, to feel assured that before Religion and Science can be reconciled by the reduction of their principles to a common Method, it will be necessary to transform Metaphysics, or to stamp it out of existence. There is but this alternative. At present Metaphysics is an obstacle in our path : it must be crushed into dust, and our chariot-wheels must pass SCIENTIFIC METHOD IX METAPHYSICS. 5 over it ; or its forces of resistance must be converted into motive powers, and what is an obstacle become an impulse. 4. It is towards the transformation of Metaphysics by reduction to the Method of Science that these pages tend. Their object is to show that the Method which has hitherto achieved such splendid success in Science needs only to be properly interpreted and applied, and by it the inductions and deductions from experience will furnish solutions to every metaphysical problem that can be rational]y stated ; whereas no problem, metaphysical or scientific, which is irrationally stated can receive a rational solution. I propose to show that metaphysical problems have, rationally, no other diffi- culties than those which beset all problems ; arid, when scientifically treated, they are capable of solutions not less satisfactory and certain than those of physics. To one class of readers, this announcement will perhaps seem extravagant, and the attempt absurd ; to another class the limitation to scientific Method will seem narrow and insufficient. But if I succeed in showing the first that solutions can thus be reached, and in showing the second that only thus can any solution be reached, the gain will be obvious : not only will a vast region of speculative disorder be reduced to order, not only will one obstacle to the reconciliation between Kelioion and Science be removed, but we shall o * be in possession of a Method which will make Keligion also the expression of Experience, and thus dissipate the clouds of mystery and incredibility which have so long concealed the clear heavens. 5. Should these pages fall into the hands of readers who on former occasions have given me their attention, 6 PROBLEMS OF LIFE AND MIND. they will doubtless feel some surprise at this announce- ment of my present aim. I may here seem to be unsaying what it has been the chief purpose of my labours to enforce. But it is not really so. I have indeed incessantly, for some thirty years, tried to dissuade men from wasting precious energies on insoluble problems ; that purpose still animates my efforts. But, although formerly I regarded problems as insoluble which I now hold to be soluble, there has been no other change than this, that I now see how problems which were insoluble by the Method then in use, are soluble by the Method of Science. This is not a retreat, but a change of front. Throughout my polemic against Metaphysics, the attacks were directed against the irrational Method, as one by which all problems whatever must be insoluble. 6. Descartes opened Modern Philosophy by his famous ' Discourse on Method/ It was a brilliant effort, but the consecration of experience has been wanting to it. History proves that it was not really capable of furnishing any satisfactory solutions. Auguste Comte opened the new era by his great conception of Method, namely, the extension to all inquiries even morals and politics of those induc- tive principles which alone have been found fruitful in any inquiries. I shall not be supposed to under- rate the value of the Positive Philosophy, as conceived by Comte, in pointing out a defect of that scheme which has often been pointed out by its opponents, namely, that it displays no effort to apply the positive Method to one great branch of speculation that of Metaphysics. He peremptorily excluded all research whatever in this direction, declaring metaphysical problems to be essen- tially insoluble, consequently idle and mischievous. SCIENTIFIC METHOD IN METAPHYSICS. 7 Nor can there be any dispute that the speculations he had in view are inane, when pursued on the Method traditionally followed; but an extension of the prin- ciples of Positivism may legitimately include even these speculations ; and Scientific Method, rightly interpreted, will find its employment there. It is surely more philosophical to bring metaphysical problems under the same speculative conditions as all other problems, than to exclude them altogether, since our ignoring them will not extirpate them. The problems exist, and form obstacles to Eesearch. Speculative minds cannot resist the fascination of Metaphysics, even when forced to ad- mit that its inquiries are hopeless. This fact must be taken into account, since it makes refutation powerless. Indeed, one may say, generally, that no deeply-rooted tendency was ever extirpated by adverse argument. Not having originally been founded on argument, it cannot be destroyed by logic. The very mind which admits your evidence to be unanswerable will swing back to its old position the instant that the pressure of evidence abates ; and the opponent whom you left yesterday seemingly converted, is found to-day no less confident than of old. Contempt, ridicule, argument, are all vain against tendencies towards metaphysical speculation. There is but one effective mode of dis- placing an error, and that is to replace it by a concep- tion which, while readily adjusting itself to conceptions firmly held on other points, is seen to explain the facts more completely. The one permanent victory over a false Method is by philosophising better. The disciples of Descartes were not drawn over to the side of New- ton by arguments exposing the imperfections of their system, but by examples of the greater sweep and 8 PROBLEMS OF LIFE AND MIND. efficiency of the Newtonian system, interpreted on principles common to Descartes and Newton : the hypothesis of vortices gradually sank into neglect when the law of gravitation was seen to be equally consistent with the mathematical principles advocated by Des- cartes, and more competent to explain the phenomena. 7. No array of argument, no accumulation of con- tempt, no historical exhibition of the fruitlessness of its effort has sufficed to extirpate, the tendency towards metaphysical speculation. Although its doctrines have become a scoff (except among the valiant few), its Method still survives, still prompts to renewed research, and still misleads some men of science. In vain History points to the unequivocal failure of twenty centuries : the metaphysician admits the fact, but appeals to History in proof of the persistent passion which no failure can dismay; and hence draws confidence in ultimate success. A cause which is vigorous after centuries of defeat is a cause baffled but not hopeless, beaten but not subdued. The ranks of its army may be thinned, its banners torn and mud-stained; but the indomitable energy breaks out anew, and the fight is continued. Nay instructive fact ! even some great captains of Science, while standing on triumphal cars in the presence of applauding crowds, are ever and anon seen to cast lingering glances at those dark avenues of forbidden research, and are stung by secret misgivings lest after all those avenues should not be issueless, but might some day open on a grander plain. They are not quite at ease in the suspicion that other minds confessedly of splendid powers can deliberately relin- quish the certain glories of scientific labour for the nebulous splendours of Metaphysics. They are not SCIENTIFIC METHOD IN METAPHYSICS. 9 quite at ease lest what to their unaided vision now appears a nebula may not one day by aided vision resolve itself into stars. This hesitation is comprehen- sible ; it is due in some measure to an imperfect appre- ciation of the limits and possibilities of Research, and in many cases due to the fact that many minds w r ell trained in Science are imperfectly trained in Philo- sophy ; hence a want of harmony in their conceptions leads them to follow implicitly in one direction the. principles which they peremptorily reject in another. 8. Few researches can be conducted in any one line of inquiry without sooner or later abutting on some metaphysical problem, were it only that of Force, Matter, or Cause; and since Science will not, and Metaphysic cannot solve it, the result is a patchwork of demonstration and speculation very pitiable to con- template. Look where we will, unless we choose to overlook all that we do not understand, we are mostly confronted with a meshwork of fact and fiction, obser- vation curiously precise beside traditions painfully ab- surd, a compound of sunlight and mist. Thus in various writings we come upon Laws which compel phenomena to obey their prescription Plans and Archetypal Ideas which shape the course of events, and give forms and functions to organisms Forces playing about like sprites amid Atoms that are at once contradictorily in- divisible and infinitely divisible Bodies acting where they are not, and Non-Being (pure space) endowed with physical properties, among others that of resistance (since Forces in spite of their alleged independence of Matter are supposed to be diminished by the spaces they traverse), these and many analogous phantoms, more or less credit- ed, too frequently hover amid phenomena, and convert 10 PROBLEMS OF LIFE AND MIND. speculation into what Hegel in another connection sar- castically calls a " true witches' circle." * 9. Why is this 1 Mainly because men of science are generally trained either to ignore all metaphysical questions, or to regard them as "mysteries which must be accepted." Some of the first have their confidence shaken by the steadfast faith of the metaphysician that the mysteries can be unveiled. Some of the second are found expressing decided opinions on those very mys- teries declared to lie beyond human ken. Both argue from metaphysical assumptions and traditions as from acceptable data. Both resemble those theologians who solemnly affirm God to be unknowable, yet neverthe- less have no hesitation in assigning attributes to his nature, and purposes to his creations. The continuance of metaphysical inquiry is, for the present at least, inevitable. The continuance of the metaphysical Method is a serious evil, and is evitable. It sustains and fortifies those theological conceptions which would be seen to be preposterous, were it not for the dialectical dexterity which presents them in a light assuredly no less rational than that in which many metaphysical conceptions are presented. It is this which causes the adhesion of so many eminent men of science to theological dogmas flagrantly at variance with their positive knowledge. Renouncing all hope of a rational solution, yet unable to release their minds from the pressure of certain problems, they fly to Faith for refuge. One of the sincerest of men and one of the * " In der That befindet man sich in einer Art von Hexenkreise worin Bestimmungen des Daseyns und Bestimmungen der Reflexion, Grund und Begriindetes, Phaenomene und Phantome in unausgeschiedener Gesell- schaft durch einander laufen und gleichen Rang mit einander geniessen." Logik, ii. 93. SCIENTIFIC METHOD IN METAPHYSICS. 11 most cautious of investigators Faraday when asked by a friend how he could believe the astounding pro- positions current in the religious sect to which he be- longed, replied : " I prostrate my reason in this matter ; for if I applied the same process of reasoning which I use in matters of science I should be an unbeliever." It was in a less philosophical spirit that Pascal wrote : " Je trouve bien qu'on n'approfondisse pas le system e de Copernic." Pascal carried even into Science his theological terror at the possible consequences of rea- soning when a dogma seemed in peril ; Faraday kept the two provinces and their two Methods distinct. It is remarkable that both these great men were not reassured by the certainty that no truth in one direction can really contradict another; and Faraday might have been told that the legitimate application of those tests and sanctions which he regarded as sufficient in physical research, might, if applied to metaphysical or theologi- cal questions, make him an unbeliever in the doctrines of his sect, but not an unbeliever in the truths which replaced them. 10. It may be noted that Metaphysics refusing to adopt the Method of Science has received the protection of Theology, but only such protection as is accorded to a vassal, and which is changed into hostility whenever their conclusions clash, or whenever argument threatens to disturb the secular slumber of dogma. Treated as a vassal by Theology, it is treated by Science as a vision- ary. Is there no escape from this equivocal position ? We have two cardinal facts to consider. First, that certain problems, though incessantly grappled with, have yielded no permanently accepted solutions. Secondly, that in spite of constant failure they press 12 PROBLEMS OP LIFE AND MDtt). on our attention with ever-renewed solicitation. Here, then, is ample justification for the attempt to create a doctrine capable of embracing all that Metaphysics rationally may seek and all that Science finds, by the reduction of both to common principles and common tests. One Method, one Logic, one canon of Truth and Demonstration must be applied to both. Which must it be ? Xot the one hitherto employed in Metaphy- sics : its incompetence is manifest in the unprogressive nature of its results. There is, therefore, only the alternative of prolonging this uncertainty, or of adopt- ing the Method which has been uniformly successful wherever rightly employed. CHAPTER II. THE CONDITIONS STATED. 11. WHAT is here proclaimed is the possibility of finding rational solutions to questions which have hitherto baffled effort. And this will be effected by invoking those principles only which are invoked in physical research. The probabilities which guide us, and the certainties on which we rest in Science, will guide us here. In such an attempt, precisely because it is a first attempt, there will assuredly be much im- perfection ; but the reader's agreement is far less claimed in respect of any particular solutions here offered, than in respect of the conditions of the search. No one thinks of discrediting scientific Method because the particular conclusions of the physicist or biologist are often debateable and sometimes false. All I claim is a recognition of the legitimacy of the attempt to apply the rational procedure of Science to every question which may rationally be asked. This is founded on the conception that under the two cardinal points of view what is to be known, and hoiv it can be known the object and the logic there is the same accordance between Metaphysics and Physics as between any two branches of inquiry Mathematics and Biology, for example. What is known, what is knowable, and what 14 PROBLEMS OF LIFE AND MIND. is unknowable in the one, and why these are so, having their counterparts in the other. The several sciences differ amongst each other by reason of the differences in their sensible data, and the complexity of the phenomena they investigate. With these differences necessarily arise different means of investigation, differ- ent tests, and different degrees of certainty. Each science has thus its special logic. The means and tests which suffice in Mathematics are no longer sufficiently comprehensive for Physics ; the logic of Biology is, in special characters, unlike that of Chemistry. Yet one Method, one Logic rules throughout ; and this general Method may be applied to problems social or meta- physical which have hitherto been investigated in a quite different spirit, and under different tests. When so applied, it will reach results having scientific cer- tainty, because conforming to the conditions of Science. More cannot lawfully be claimed. If after all efforts there still loom in the distance vast stretches of un- trodden ground, . and beyond these a region inaccessi- ble to man, this is equally true of all research. I do not claim a wider reach, nor a higher validity, for metaphysical conceptions than for scientific concep- tions ; but I claim one equivalent reach and validity. To many minds this holds out promise of but a meagre result : impatient to pass beyond the limits of Experi- ence they will reject a solution which confines them within the human horizon. That which fascinates them is the hope of passing beyond this horizon. It will, therefore, be incumbent on me to show that such a hope is futile ; and per contra that every question which can be stated in terms of Experience is capable of an answer on the Experiential Method. SCIENTIFIC METHOD IN METAPHYSICS. 15 12. Not unfrequently in recent times have men professed to apply the Inductive Method to Metaphy- sics, and proclaimed that they were guided by it in their speculations. Nay, even the very pretension of deducing metaphysical conclusions from the data of Experience has not been wanting. But to the best of my knowledge all such pretensions have been illusory, partly because the writers imperfectly understood the Method of Science, and mainly because they did not consistently apply it. The idea of applying such a procedure is one thing; how it can be appplied is another. At this present moment I have a conviction that the Differential Calculus could be applied to Psychology, and will be in some future time ; but I have no distinct vision of how to make the beginning, because I cannot yet determine the co-ordinates, cannot put the questions in a calculable shape. It has been thus with philosophers who talked of applying Scien- tific Method to Metaphysics. Unless I deceive myself these pages will show how the problems may be pre- sented in a soluble shape ; how they may be affiliated to all other soluble problems. 13. By way of preliminary I will ask permission to coin a term that will clearly designate the aspect of Me- taphysics which renders the inquiry objectionable to scientific thinkers, no less than to ordinary minds, be- cause it implies a disregard of experience ; by isolating this aspect in a technical term we may rescue the other aspect which is acceptable to all. The word Meta- physics is a very old one, and in the course of its his- tory has indicated many very different things. To the vulgar it now stands for whatever is speculative, subtle, abstract, remote from ordinary apprehension ; and 16 PROBLEMS OF LIFE AND MIND. the pursuit of its inquiries is secretly regarded as an eccentricity, or even a mild form of insanity. To the cultivated, it sometimes means Scholastic Ontology, sometimes Psychology, pursued independently of Bio- logy, and sometimes, though more rarely, the high- est generalisations of Physics. In spite of this laxity in its use, the term is so good a term, and has had godfathers so illustrious, that if possible it ought to be preserved. And it may be preserved if we separate it from its Method, and understand it in its primitive sense as TO, /^era ra va~LKa, that which comes after Physics, and embraces the ultimate generalisations of Research. It thus becomes a term for the science of the most general conceptions. This is the Aristotelian view of it, adapted to modern thought. It is also in accordance with the scheme of Bacon, which represents Philosophy as a pyramid, having the history of Nature for its basis, an account of the powers and principles which operate in Nature (Physics) for its second stage, and an apex of formal and final causes (Metaphysics) for the third stage."''" Let us only modify the Baconian conception by substituting " the highest generalisation of Research," in lieu of the " formal and final causes," and we have a grand province to bear the ancient name. 1 4. But what is implied in this arrangement ? That since we are to rise to Metaphysics through Science, we must never forsake the Method of Science ; and further that, if in conformity with inductive principles we are never to invoke aid from any higher source than Ex- perience, we must perforce discard all inquiries what- * Compare the passage, too long for extract, in SECCHI : L'unild, delle Forze Fisiche. Rome, 1864, p. 470. SCIENTIFIC METHOD IN METAPHYSICS. 17 ever which transcend the ascertained or ascertainable data of Experience. Hence the necessity for a new word which will clearly designate this discarded re- mainder a word which must characterise the nature of the inquiries rejected. If then the Empirical desig- nates the province we include within the range of Science, the province we exclude may fitly be styled the Metempiricdl. The terms Empiricism, Empiricist, Empirical, al- though commonly employed by metaphysicians with contempt, to mark a mode of investigation which admits no higher source than Experience (by them often unwarrantably restricted to Sensation), may be accepted without demur, since even the flavour of con- tempt only serves to emphasise the distinction. There will perhaps be an equivalent contempt in the minds of positive thinkers attaching to the term Metempirical ; but since this term is the exact correlative of Empirical, and designates whatever lies beyond the limits of pos- sible Experience, it characterises inquiries which one class regards as vain and futile, another as exalted above mere scientific procedure. Nor is this the only advan- tage of the term; it also detaches from Metaphysics a vast range of insoluble problems, leaving behind it only such as are soluble. 15. Thus whatever conceptions can be reached through logical extensions of experience, and can be shown to be conformable with it, are legitimate products, capable of being used as principles for further research. On the contrary, whatever lies beyond the limits of Expe- rience, and claims another origin than that of Induc- tion and Deduction from established data, is illegitimate. It can never become a principle of research, but only VOL. T. B 18 PROBLEMS OF LIFE AND MIND. an object of infertile debate. The metempirical region is the void where Speculation roams unchecked ; where Sense has no footing ; where Experiment can exercise no control ; and where Calculation ends in Impossible Quantities. In short, Physics and Metaphysics deal with things and their relations, as these are known to us, and as they are believed to exist in our universe ; Metempirics sweeps out of this region in search of the otherness of things : seeking to behold things, not as they are in our universe not as they are to us it substitutes for the ideal constructions of Science the ideal constructions of Imagination. 16. The reader may here ask how it is that great metaphysicians, like Descartes, Leibnitz, and Kant, who were also great scientific thinkers, failed to perceive that the Method they followed in Mathe- matics and Physics was equally applicable in Meta- physics ] The answer is simple. The traditional in- fluence of metempirical conceptions, and the potency of certain prejudices, which Science confessed its ina- bility to justify or eradicate, prevented these philoso- phers from even conceiving the possibility of excluding metempirical data. Kant who, in his exposition of the relativity of knowledge, came so near a true con- ception of Method, not only missed the truth, and fell back upon the traditional prejudice of Innate Ideas, or a priori Forms of Thought, as the source of knowledge, but expressly declared that "the fountain of Meta- physic can in no sense be empirical, its axioms and principles must never be drawn from Experience, either inward or outward," * a declaration which ceases to be * KANT : Prolegomena zujeder kiinftigen Metaphysik, 1. It is true that by Metaphysic he sometimes only means the inquiry into the limits SCIENTIFIC METHOD IN METAPHYSICS. 19 even plausible when his unwarrantable restriction of Experience to mere sensation is set aside. Nor is this all. Granting that Metaphysic could dispense with the inductions of Experience, all that it could effect for Philosophy would be the superfluous explanation of phenomena which lie outside the circle of Experience ; whereas Philosophy aims at an explanation of the world in which we have our being. Consider this : If abstract Science, which obtains its principles through ' concrete phenomena, is confessedly incapable of explain- ing concrete phenomena, but only capable of guiding us to their explanation, how much less hope can there be of an explanation of concrete phenomena from principles that do not pretend to an empirical basis ! Kant displayed great ingenuity in proving that the empirical and metempirical worlds (by him called the phenomenal and noumenal) having nothing in com- mon, no conclusions formed respecting the one could have any validity when extended to the other. Why, then, did he continue to coquet with Metempirics, after having struck such blows at its foundation ? I believe it was partly the consequence of the traditional conception that metempirical knowledge was possible ; and partly the want of any clear conception of how the Method of Science could be applied to questions wilich insisted on an answer. 17. Hegel, on the other hand, is urgent for treating Metaphysics and Science on the same Method. Unhap- pily he has a very erroneous view of the conditions of inquiry ; and in point of fact reverses the principle I am here proclaiming, and instead of treating Meta- of knowledge ; but at others be means what is usually meant by the word, namely, metempirical inquiry. 20 PROBLEMS OF LIFE AND MIND. physics by the Method of Science, treats Science by the Method of Metaphysics. He separates the philo- sophical sciences into empirical and speculative. The empirical embrace those which furnish axioms, laws, theories the thought of what is actual. So far he seems to be arguing on our side ; but he adds, " How- ever satisfactory this knowledge may be in its own field, there are other subjects which it does not include Freedom, Mind, God." * And elsewhere ( 37) he characterises the tendency to prove everything by finite consideration as " Empiricism, which instead of seeking truth in Thought itself seeks it in groping amid Ex- perience inward and outward ; " adding that consequent Empiricism excludes all knowledge whatever of the Suprasensible. It is unnecessary to pause and consider under what aspects Hegel's view coincides with the strictly positive conception of Research ; all we have here to note is the retention of those very metempirical elements, which it is the aim of Science to exclude. In point of fact, when we see Hegel at work we find that the metempirical is not kept apart from the empirical, but dominates it ; and his inquiries in Physics no less than in Psychology are all vitiated by this. 18. Thus while metaphysicians have never really applied scientific Method, because they have never re- linquished their faith in the Metempirical, men of * " Wir heissen jene "Wissenschaften, welche Philosophic gennant \vorden sind, empirische Wissenschaften, von dem Ausgangspunkte den sie nehmen. Aber das Wesentliche das sie bezwecken und hervorschaffen sind Gesetze, allgemeine satze, eine Theorie ; die Gedanken des Vorhan- denen. ... So befriedigend zunachst diese Erkenntniss in ihren Felde 1st, so zeigt sich furs erste noch ein anderer Kreis von Gegenstanden die darin nicht befasst sind Freiheit, Geist, Gott. Sie sind auf jenem Boden nicht darum zu finden weil sie der Erfahrung nicht angehoreii sollten. HEGEL : Encyklopadie der Philos. Wissensc/taften, 7, 8. SCIENTIFIC METHOD IN METAPHYSICS. 21 science have never thought that their Method could be applied to Metaphysics, because they imagined that Metaphysics was inseparable from Metempirics. It is this misapprehension we must rectify by showing that the problems rightly stated, are empirical pre- cisely in the degree that physical problems are so ; and that both are in an equal degree metempirical when improperly stated. Scientific thinkers', viewing certain questions solely in the light in which meta- physicians were accustomed to place them, and seeing that to these no application of ordinary tests was applicable, declared and the declaration rapidly be- came a dogma that "all such questions relate to mysteries beyond human ken." With this magisterial phrase they justified their neglect of problems they were unable to solve. 19.- Such lavish humility is far from admirable, Such readiness to admit mysteries is misleading. "We have no right by self-abasement to abase Humanity, and thus present our own incompetence as the standard of power. Particularly objectionable are these professions of humility when accompanied, and they often are, by exaggerated pretensions, so that the man who considers it almost a religious duty humbly to avow his eternal ignorance of Cause, Force, Mind, and the like, has no hesitation in expressing decided and precise opinions respecting their nature and modes of operation. It is thereby manifest that the ignorance on which he eloquently insists is your ignorance rather than his. Nay even when this is not so, and he avows his ignorance sincerely, he is too apt to regard the avowal as an act of piety a confession of his " no- thingness." 22 PROBLEMS OF LIFE AXD MDsD. Philosophy thus boasting of its own impotence, is a tradition of that theological spirit which, terrified at the free exercise of Doubt, yet conscious of the necessity of Doubt for the activity of Eeason, excommunicated the Intellect as an heresiarch, after having vilified this life as a theatre for Satan. There was a time when all knowledge was considered dangerous, except for theo- logians and lawyers ; for others it was of the nature of Magic. The tradition still lingers ; and a vague hor- ror hangs over all "prying into the mysteries of the universe." It may be noticed influencing audiences at almost every scientific lecture not addressed to students. Ludicrous, were it not painful, would be the eagerness of delight with which every acknowledgment of igno- ance and incompetence is saluted by the listeners. Although they are seated there to learn what has been discovered respecting the processes of Nature, they are never so well pleased as when told that what has been discovered is nothing compared with the undiscoverable. Let but the lecturer say and he must often say it " Here Science pauses. Beyond this we cannot go. Beyond this lie mysteries before which the wisest philosopher is no better than a child " immediately a round of applause bursts forth : numerous feet stamp approval ; flattered Ignorance feels at ease, and shakes its head significantly. " Ah ! you see, Science is vain there. In spite of its proud boasts, there are mysteries it cannot penetrate ! " . . . Now surely it is no matter of exhilaration, but rather of deep regret, that we find ourselves in a universe of mystery, compelled to grope our way amid shadows, with terrible penalties affixed to each false step. To SCIENTIFIC METHOD IN METAPHYSICS. 23 resign ourselves to this condition is one thing ; another to exult in it, and claim the exultation as an act of piety. Among the many strange servilities mistaken for pieties, one of the least lovely is that which hopes to flatter God by despising the world, and vilifying human nature."''" 20. There is no intention here of applauding the unthinking confidence which leads many minds to pursue inquiries beyond their powers; nor of under- rating the lessons which dissuade us from such efforts. It is of supreme importance that we should ascertain the limits of Eesearch. But these limits must be ascer- tained, not arbitrarily assigned. Before declaring any subject inaccessible, to others no less than to ourselves, we must clearly see the grounds why it is so ; and before attempting to reach one that is accessible we must have some vision of the path by which it may be reached.t Inaccessibility is relative, and science has answered questions which, to minds unfamiliar with its data and procedures, might seem hopelessly beyond human power ; which indeed, in the absence of such data and procedures, would be beyond it. What, for example, could be more absurd than for one of the laity to attempt to measure and weigh stars many millions of millions of miles removed from his grasp \ or to ascertain the velocity of Light or of the 1 translation * The Author of Creation is the onty author who is supposed to be flattered by our lavish assurance that his works are imbecile. t The padre SECCHI, noticing the readiness with which men conclude that nothing is known on certain subjects, quietly remarks that this is a conclusion " che se onora il filosofo ove manchi fondamento alia dedu- zione, lo degrada ove derivi dal non saper intendere il linguaggio della Natura." L'Unita ddle Forze Fisiche, 1864, p. 51. 24 PROBLEMS OF LIFE AND MIND. of our solar system towards the constellation of Her- cules ? Yet, Geometry, Trigonometry, and Dynamics render these things possible. We believe the state- ments that the sensation of violet is produced by the striking of the ethereal waves against the retina more than seven hundred billions of times in a second and that our sun and its planets are moving through space with a velocity of many millions of miles in a year ; but these statements are accepted on trust by us who know that there are thinkers for whom they are irresistible conclusions; the facts belong to mysteries penetrable only through a mathematical initiation. 21. It is thus also with Metaphysics. Its pro- blems are inaccessible, and must remain so to minds which will not approach them through the only ac- cessible path. But there is a path through which they may be accessible ; all depends on our selecting it. A few years since it would have been preposterous to speculate on the present chemical constitution of the sun's atmosphere ; it would have been one of the mys- teries which no astronomer would consider investigable. Why \ Simply because there were no accessible data. The question was one wholly beyond the known paths. It was so obviously metempirical that even metaphysi- cians abstained from speculating on it. Suddenly the discovery of spectrum analysis placed an instrument in our hands, by which the presence of gases and vapours in the sun's atmosphere could be ascertained as rigor- ously as their presence in our laboratories. The mys- tery submitted to demonstration. Newton's feat of in- terpreting celestial Mechanics by the laws of motion detected on our planet (with the consequent reflected SCIENTIFIC METHOD IN METAPHYSICS. 25 improvement in the definition of those very laws) was supplemented by the identification of the chemistry of the stars with that of our planet, and the consequent revelation of new substances in our earths and waters, which might otherwise have remained unsuspected. In like manner one may hope that the application of scientific Method to problems hitherto inaccessible may reflect light on questions of Science otherwise hope- lessly obscure. (Compare 62 a.) 22. In saying that all depends on the selection of the right path, I may appear to be uttering a truism, the very difficulty being precisely this selection. It is, how- ever, only a truism to those who believe such a path may be found. The majority do not believe it, but insist that Metaphysics is essentially removed from any access through Experience. There is something gained, then, if we gain the admission that a pathway through Experience is possible. To effect this it may be re- quisite to show that unless some stringent proof be ad- vanced in support of the assumption that the human mind is endowed with a special organ for the perception of metempirical relations, there must either be a total abandonment of metaphysical Speculation, or an adop- tion of the empirical Method. And I hope to show that there is no such special organ. Meanwhile let us here consider two favourite arguments for the continu- ance of the old speculations, with which metaphysicians vindicate their neglect of science. 23. First, it is said that " a noble impulse moves the BOU! to rise above the sordid aims of Science, which is mainly anxious to satisfy our vulgar needs." This ascription of a nobler aim must be rejected, not only 26 PROBLEMS OF LIFE AND MIND. because of its unwarrantable self-complacency,* but because of its misrepresentation of the true position of Science which as will hereafter appear (PptOB. I. chap, v.) is purely that of an Ideal Construction. Science is an idealist, moving amid the world of realities as if they were but fleeting shadows, and as if the only perma- nent existences were Abstractions. But were this otherwise, and were the satisfaction of our commonest needs the only aim, the objection would be none the less misplaced. There is no greater vulgarity than that of despising the common needs of life as vulgar. It is the greatness of Science that while satisfying the spiritual thirst for knowledge, it satisfies the pressing desire for guidance in action : not only painting a pic- ture of the wondrous labyrinth of Nature, but placing in our hands the Ariadne-thread to lead us through the labyrinth. 24. The second plea urges that, granting the study to be doomed to failure, the mere energy it evokes is so strengthening and ennobling that Metempirics must always be an admirable course of intellectual gymnas- tics. The answer to this is simple. Without denying that intellectual athletes may find in it an arena for the exercise and display of their powers, we may urge that there are other and nobler arenas than the Gymnasium, * It is in this sense that HEGEL likens a people without Metaphysic to a temple without its Holy of Holies. " These be brave J orts," as Sir HUGH EVANS would say ; and would be justified if the pretensions 01 Metaphysic were justified ; but when we examine these we come to TRENDELENBURG'S conclusion respecting the Hegelian procedure : " Man fragt nicht mehr was mit menschlichen Mitteln geschehen kann, sondern was nach hoheren Ideal geschehen sollte. Man nimmt die Absicht der Dialektik fur die That. Aber weil sie hoch greift, hat sie nicht das Hohe ergriffen ; und weil sie mehr verspricht, ist das Versprochene noch nicht dsi."Logische Untersuchunyen, 1862, i. 105. SCIENTIFIC METHOD IN METAPHYSICS. 27 where the greatest powers may not only be freely exer- cised, but exercised for the welfare of mankind. The measureless region of scientific Kesearch is not only capable of calling out every intellectual faculty, but is one in which no exercise is sterile."" Incapable of ap- plication to concrete phenomena and the practical needs, incapable of demonstration because incapable of verifi- cation, the most splendid achievements in the metem- pirical arena are sterile displays. 25. Although it is true that only those problems which are capable of solution can profitably employ mankind, the common assertion that metaphysical problems are incapable of solution is true when there is a tacit assumption that they can only be inves- tigated on the Metaphysical Method. But the whole subject changes its aspect directly we institute the dis- tinction between Metaphysics and Metempirics. Un- less this distinction be clearly maintained all problems whatever become hopeless, and we are incapable of ex- plaining the simplest phenomenon; with this distinc- tion, all problems whatever become capable of solution, under empirical limits. 26. The objection will doubtless be raised that such a procedure as that of excluding all metempirical data, and rejecting all metempirical inquiry, is an obliteration of the characteristic peculiarity of Metaphysics, and an evasion of the difficulty. It will be urged that an em- pirical answer to speculative questions can never satisfy the mind yearning for insight into the world of things behind phenomena for knowledge of the otherness of things for glimpses of " the light that never ivas on sea or shore." This is so. But we must remember that * Compare on this subject COMTE : Politique Positive, iii. 13, 14. 28 PROBLEMS OF LIFE AND MIND. whatever speculative curiosity may prompt, our real and lasting interest is in ascertaining the order of the things we know. A sublime aspiration after the otherness of things is sublimely irrational. To know things as they are to us, is all we need to know, all that is possible to be known; a knowledge of the Suprasensible were it gained would, by the very fact of coming under the conditions of knowledge, only be knowledge of its relations to us, the knowledge would still be relative, phenomenal.* * "What Prof. TAIT says of Quaternions may here be made to illustrates the distinction between the empiricist and metempiricist, if we allow the pure mathematician to stand for the latter : " In the eyes of the pure mathematician Quaternions have one grand and fatal defect. They cannot be applied to space of n dimensions ; they are contented to deal with those three poor dimensions in which mere mortals are doomed to dwell. From the physical point of view this, instead of being regarded as a de- fect, is the greatest possible recommendation. It shows in fact Quater- nions to be a special instrument so constructed for application to the Actual as to have thrown overboard everything which is not absolutely necessary, without the slightest consideration whether or not it was thereby being rendered useless for application to the Inconceivable." Address before the Mathematical Section of the British Association, 1871. CHAPTER III. THE METHOD. 27. A MOMENT'S reflection will show that the Experien- tial Method is by no means restricted to that enumera- tion of particulars and classification of sensations which is assumed to be its scope by those philosophers who vilify it under the name of Empiricism, and those rhetors who declaim against it as dealing with nothing but what can be seen and felt. It is the methodising of what is known. The range of the known embraces much more than the sensible. (See PROB. I/, ch. iv.) Not only the direct presentations to Sense, but the indirect representations the verifiable Inferences from Sense constitute its elements. Not only the individual experiences, slowly acquired, but the accumulated Ex- perience of the race, organised in Language, condensed in Instruments and Axioms, and in what may be called the inherited Intuitions these form the multiple unity which is expressed in the abstract term Experience. This being stated once for all by way of forestalling hasty criticism, let us now proceed with our exposition. 28. Whether the object of research be Nature, Man, or Society in general, or some special group of their phenomena, we always find it presenting three aspects : 1, the positive or known ; 2, the speculative or 30 PROBLEMS OF LIFE AND MIND. unknown though knowable ; 3, the unknowable. The two first are empirical ; the third is metempirical. The two first rest either, 1, on direct Sensation and verified Inference,*" or, 2, on Intuition and logical deductions from Intuition, which are verifiable by direct, or indirect, reduction to Sensation. The third rests on no such bases, and is therefore distinguishable from the two former in kind, not simply in degree. 29. By way of illustration, suppose the object inves- tigated is the motion of the heavenly bodies. The first step is to determine the positive, or known, elements of the question, namely, that all the planets move round the sun in the same direction and in nearly the same plane, and that, inasmuch as their orbits are nearly circular, they describe paths which are parallel. This general plane of circulation is very nearly the plane of the sun's equator. The same facts are ascertained respecting the motion of the satellites round their planets, although their equators have various inclina- tions to the plane of the sun's equator. This leads to the inference that the two circulations of plane'ts and satellites, although independent as facts, depend on the same principle, and have a common origin. What is that ? This question brings forward the speculative aspect. The principle sought cannot be seen, it must * " In the experimental department," says Professor CHALLIS, "a law is a grouping of observed facts ; in the theoretical, the law is shown to be the consequence of certain primary facts. Every fact and every law which experiment makes known is a problem for the theorist to solve by mathematical reasoning " aided by Conjecture, let us add. Thus KEPLER discovered the fact that the radius vector of each planet describes round the sun equal areas in equal times, and conjectured that each planet tended continuously towards the sun in consequence he thought of a magnetic power : this was a conjecture supporting a conjecture. NEW- TON grasping the fact observed, and the fact conjectured, solved the pro- blem by mathematical reasoning which dispensed with the hypothetical magnetic power and disclosed the law. SCIENTIFIC METHOD IN METAPHYSICS. 31 be deduced. Speculation is seeing with the mind's eye what is not present to Sense or to Intuition. It is ideal construction, and begins with conjecture too often, alas ! ending where it began. The satellites present also another remarkable law, their rotation on their own axes being executed in the same time as their rotation round their planets (hence we always see the same face of the moon). This law is positive ; it is the observed order. But the cause, i. e., that it depends on tidal friction in the satellite while it was still in motion, is at present speculative. Suppose now the astronomer, after expounding the positive and speculative aspects of the planetary mo- tions, is led to expound his conception of the purpose which these laws were intended to fulfil in creation, and his estimate of the wisdom and benevolence in so disposing them, and not otherwise is it not obvious that in this teleological explanation he quits the ground of Experience to enter on that region where all sensible data and all verifiable inferences vanish 1 His con- jectures on this point may be approximately right, or absurdly wrong; no possible means of determining whether they are right or wrong exist. If he regard them as no more than subjective fancies wherewith to satisfy his own feelings, we cannot object. But if he regard them as in any degree entering into astronomical science, and if he permit any deductions from them to modify the positive and speculative data or in any way to modify the course of astronomical thought, he violates the first principle of Method, by suffering the empirical to be controlled by the metempirical, and allowing the unknowable to distort the known. 30. Having thus sharply defined the three aspects which every question may present, and which every 32 PEOBLEM3 OF LIFE AXD MIXD. one would always present had not men long ago quietly set aside the metempirical aspect in most questions of practical aim, and most questions of scientific research, I need scarcely insist that in dealing with the specula- tive we ought to follow the same canons as in dealing with the positive, except that we are forced to substitute analogies for perceptions, forced to employ hypotheses and rely on inferences. When a platinum wire is raised gradually to a white heat> we see a succession of combinations of more and more of the primitive colours, but we do not see the motions of the wire which succes- sively determine these colours, nor the tremors of the optic tract which are determined by these motions and produce these colours. We only see the changing colours. We infer the rest. But these inferences have been veri- fied a thousand times, and are but reproductions of analogical experiences. Our mental vision is a repro- duction of the past and application to the present. It is Experience our own or that of others on which we rest. We are not at liberty to invent Experience, nor to infer anything contrary to it, only to extend it analogi- cally. Speculation to be valid must be simply the ex- tension of Experience by the analogies of experiences.* * " From a starting-point furnished by his own researches, or those of others, the investigator proceeds by combining intuition and verification. He ponders the knowledge he possesses, and tries to push it further ; he guesses, and checks his guess ; he conjectures, and confirms or explodes his conjecture. These guesses are by no means leaps in the dark ; for know- ledge once gained casts a faint light beyond its own immediate boundaries. . . . The profoundest minds know best that Nature's ways are not at all times their ways, and that the brightest flashes in the world of thought are incomplete until they have been proved to have their counterparts in the world of fact. Thus the vocation of the true experimentalist may be denned as the continued exercise of spiritual insight and its inces- sant correction and realisation." TTXDALL: Fragments of Science, 1871, p. 110. SCIENTIFIC METHOD IN METAPHYSICS. 33 31. The speculative begins where the positive ends; and where the speculative quits the ground of Sense and Verification, the region of the Metempirical begins. It is possible to move securely on the ground of Specu- lation so long as we carefully pick our way, and consider each position insecure till what was merely probable becomes proven. But in the metempirical region we have not even probability as a guide : it is a morass of uncertainty where all footing yields, and all tests fail. In this region, conjectures however fantastic are as valid as conceptions which seem rational. They maintain their ascendancy over the mind which has once admitted them, because being, by the nature of the case, incapable of proof, they are incapable of refutation : they never approach near enough to the truths of Experience for us to show how widely they diverge from or contradict it. 32. Whenever a question is couched in terms that ignore Experience, reject known truths, and invoke inaccessible data i. e., data inaccessible through our present means, or through any conceivable extension of those means it is metempirical, and Philosophy can have nothing to do with it. We need not trouble ourselves with it, until in possession of the requisite means ; it is adjourned, not suppressed. Perilous it may be to set bounds to human possibilities, and to forejudge what future inquiries may disclose ; but there is no peril in standing inflexibly by the rule which declares all questions to be unanswerable when the means of answering them are not at hand. He who propounds an answer is called upon to show that he has the requisite means. What is invisible to the naked eye may be made visible by microscope or telescope. VOL. i. c 34 PROBLEMS OF LIFE AXD MIXD. Let these be produced, and their powers demonstrated. No assertion however confident will suffice ; no " inner vision " which dispenses with verification. Roger Bacon passionately declared that he could construct an instru- ment which would make objects visible at a distance of many miles ; and because such instruments have been constructed, he is believed to have anticipated the discovery, whereas, in point of fact, he not only made no such discovery, but showed, in his very statement of the conception he had formed, that he had not mastered the elementary principles which were requisite. The theories of many speculators are in this not unlike the telescope of Roger Bacon. 33. While no question which cannot be couched in terms of Experience, and answered on its data, ought for a moment to be entertained ; any question which can be so asked and answered is admissible. In Sci- ence this has long been understood; in Metaphysics it is ignored. No geologist, no biologist would listen patiently if asked, What is the succession of strata in Sirius ? What are the leading characters of the flora and fauna of Saturn? Yet metaphysicians patiently listen to questions of equal irrelevance; nay, confi- dentlv give answers to them. o Without travelling so far as Sirius, suppose we pre- sent a new substance to the chemist, and ask him what are its properties, and what reactions it will exhibit under given conditions. He will decline to answer until he has sufficiently examined the substance and classed it among substances already known ; because he is aware that any guess he may make before trial must be valueless unless guided by analogy ; in as far as it is like known substances he will infer that it has SCIENTIFIC METHOD IN METAPHYSICS. 35 like properties. Guessing is only fertile in proportion to the fertility of the experiences it reproduces. If a man knows little, he can infer but little. All know- ledge is reproduction of experiences, the direct, or in- direct assimilation (making like) of the new phenomena to phenomena resembling them, formerly experimented on. Ask the profoundest analyst to resolve an equation numerically, and he is silent unless the values of the coefficients are assigned: nor can the child tell the result of multiplying 5 by 5, until he has learned the multiplication table. 34. Must not this be equally true in Metaphysics 1 To ask the metaphysician to answer questions respect- ing things per se (or what is usually understood by them), and to tell us their nature and properties, is asking him to resolve equations numerically without assigning their several values to the coefficients. Nay more, these values cannot be assigned, for the symbols profess to be symbols of what was never presented in Experience. But if instead of this irrational procedure we give the metaphysician verifiable data, he can deal with them as the physicist and chemist deal with theirs; and his answers will be as valid as theirs, if his data and method be like theirs. 35. Hitherto metaphysicians have asked, What isMat- ter? What is Force ? What is Cause ? And these words are symbols of an imaginary class of Noumena, Dinge- an-sich, Things as they are and underlying the Things which appeal a world behind phenomena, incapable of being sensibly grasped, but supposed to have a moro perfect reality than the phenomenal world. Be- cause questions thus irrationally put are found to yield no rational answers, one class of thinkers hurries 36 PROBLEMS OF LIFE AND MIND. to the conclusion that this impotence proves all meta- physical inquiries to be idle ; another class infers that knowledge of this superior world must be gained through another source than that relied on in the in- vestigation of phenomena. But we may urge that all inquiries are not idle because some are improperly con- ceived ; nor is any special organ needed for the inter- pretation of questions rationally put. Since it is a fact that we have ideas of Matter, Force, Cause, &c., and that these words are symbols of sensible experiences, the genesis of such ideas and the interpretation of such symbols are not less legitimate objects of inquiry than the genesis and interpretation of our ideas of Animal, Plant, Planet, or Cosmos. I shall hereafter endeavour to make clear that these abstract ideas are integrant parts of what I call the Logic of Feeling, before they are raised into terms of the Logic of Signs. They are threads woven into the web of Experience ; and because they have this warp and woof they are capable of being raised into the tissue of Abstraction they are experi- ences before they are signs. The Method which enables us to unravel the complex threads in the one case will aid us in the other. 36. As already hinted, the chief source of perplexity is the irrationality of the terms in which the questions are propounded. But although this defect is specially flagrant in the case of Metaphysics, it is frequently noticeable in Physics. Take, for example, the puzzle concerning the communication of motion from one body to another, either through impact or " action at a dis- tance." This communication is accepted as a fact, and declared to be beyond our comprehension. The incon- ceivability of the statement is not allowed to suggest a SCIENTIFIC METHOD IN METAPHYSICS. 37 doubt respecting its certainty. But the inconceivability, when closely examined, will be found to rest entirely on the irrational mode of expressing the fact observed ; instead of stating what is observed in simple terms, the statement is made in terms of an hypothesis which cannot be steadily conceived. What is observed is that one body in motion, that is to say, in changing space relations, is succeeded by changes in the space relations of another, and that there is a constancy in this sequence. This not being held sufficient, there is invented a hypothetical Motion (not an abstract sym- bol, but a physical, entity), which is passed from one body to another like so much milk poured from one jug into another; and to complete the hypothesis this Motion is imagined under the control of the body moving, since this body divides its quantity of Motion, keeping one portion to itself and communicating the other portion to the other body ! Is it strange that having travestied the observed phenomena in this way, and accepted our metaphorical language as exact, we marvel that the entity thus created is beyond comprehension I Instead of throwing the onus on human incompetence, suppose we ask whether it may not rest on the illusory state- ment ? Analyse the real data, and it will then be seen that the " communication of Motion " is one of those metaphorical phrases which (as Lagrange remarks, on a somewhat similar occasion""") are supposed to reveal the essence of Nature's laws, and which can "par quelque vertu secrete eriger en causes finales, de sim- ples resultats des lois connues de la mecanique." We first raise a dust and then exclaim, " Impossible to see through it ! " * LAGEANGE : Mecanique Analytique, 1811, i. 245. .38 PROBLEMS OF LIFE AND MIND. 37. Of a similar kind is the puzzle respecting Force inherent in Matter. Neither abstraction is reduced to its concretes, neither term accurately defined; and then such questions as the following are asked (which I cite from a distinguished mathematician and physicist, Maupertius) : " Qu'est ce que cette force impulsive ? comment reside- t-elle dans les corps? qui eut pu deviner qu'elle y reside avant que d'avoir vu des corps se choquer ? La residence des autres proprie'tes n'est pas plus claire. Comment rimpene'trabilite' et les autres proprie'te's viennent elles se joindre a 1'etendue "? " When such questions are detached from a work and seriously considered, it seems difficult to understand how any thinking mind could have propounded them. Yet, having puzzled himself with irrational questions, Maupertius evades them with the customary formula : " These must ever remain mysteries for us." Mysteries no doubt ; but mysteries quite needlessly fabricated. 38. Examples need not be multiplied ; enough if we understand that every problem is mysterious when irrationally stated ; but, when rationally stated, there is no greater mystery in the existence of an external world, or the relation between Object and Subject, than in the relation between activity and waste in the tissues, the relation between heat and expansion, or the relation between an arc and its chord. The successful interro- gation of Nature mainly depends on the selection of the question to be put, and the ability with which it is ex- pressed in terms that admit of an answer. Hence the first operation in dealing with any metaphysical pro- blem must be this : * MAUPERTIUS : Sur les figures des astres. (Euvres. Dresden, 1752, p. 65. SCIENTIFIC METHOD IN METAPHYSICS. 39 To disengage the metempirical elements, and pro- ceed to treat the empirical elements with the view of deducing from them the unknown ele- ments, if that be practicable, or, if the deduction be impracticable, of registering the unknown elements as transcendental. This procedure seems very simple. It is the ordi- nary procedure of the analyst, whose first operation is to disengage the unknown quantity and of the physicist, who always seeks to eliminate whatever is irrelevant or indeterminate, replacing it by exact data, so that nothing finally remains for exploration but what is expressible in calculable terms. Yet simple as the procedure may seem, it has rarely been adopted by metaphysicians ; and never, I believe, avowedly stated as a principle of research. On the contrary, there has been a coufused mingling of empirical and metempiri- cal elements, sensations and abstractions, inferences and traditions, exact quantitative data, and imaginary unquantitative data, facts and phrases, phenomena and phantoms and then it is thought marvellous that such a network of cordage and cobweb should let everything run through! 39. Our first operation must be to disengage the unknown quantity, and endeavour to ascertain whether it is knowable or unknowable ; and this will determine whether it is empirical or metempirical. In every question, from that presented by the growth of a blade of grass, to that presented in the evolution of a social organism, from the chemical union of two gases to the formation of ideal types, there must necessarily be certain transcendental elements, not de- terminable by us, unexplored remainders after the 40 PROBLEMS OF LIFE AtfD MIND. most exhaustive exploration. These may be grouped under three heads : 1. Elements known to be present in the phenomena, but not yet quantitatively appreciable, and therefore now incalculable ; 2. Elements not certainly known to be present, but assumed hypothetical^ for the sake of provisional explanation ; 3. Elements which lying beyond all possible appre- ciation, because incapable of being brought within the range of Sense and Inference, are to be set aside, and not allowed in any way to enter into the explanation. 40. An illustration or two may here be useful. Geometers agree that the exact ratio of the circumfer- ence of a circle to its diameter cannot be accurately expressed in ordinary finite numbers, although the real value may be approached as nearly as we please.* They indicate this ratio by the sign IT a sign which dispenses with a long series of figures and an unexplored re- mainder. This sign, although entering into the expres- sion of the quantities compared, does not enter into the * The impossibility of squaring the circle is the attempt to find a straight line the square on which shall be exactly equal to a given circle. The impossibility of expressing the ratio of diameter and circumference in finite numbers was first demonstrated by LAMBERT in 1761, according to DE MORGAN. I imagined from EULER'S language that the use of the sym- bol TT was proposed by himself (Introd. & I' Analyse des inifiniments petits. Traduit par PEZZI. Strasbourg, 1786, chap, viii.), but a friend informs me that this is not the case. EDLER gives 128 decimal places ; subsequently VEGA carried the expression as far as 140 places. Now, when it is considered that the first decimal involves only a defect of hundreds, and ten decimals a defect less than one inch compared with the circumference of the whole earth, we may say with LESLIE that VEGA'S was the " luxury of calculation, and, though superfluous, might convince any judicious person of the impossibility of stating the ratio infinite terms." SCIENTIFIC METHOD IN METAPHYSICS. 41 expression of their ratios, but' vanishes from the final equation. Thus the surface of a sphere, and the surface of a great circle of that sphere, are two quantities which cannot be accurately expressed in numbers, because TT enters into both, and this TT containing an unexplored remainder must remain transcendental. Nevertheless the presence of this transcendental element produces no disturbance in the calculation ; for we are certain that the first quantity is exactly the quadruple of the second, whatever values these may have. Thus the transcendental element, which exists in both quantities, disappears from the ratio of the one to the other. We thus lay down the important formula : The existence of an unknown quantity does not necessarily disturb the accuracy of calculations founded on the known functions of that quan- tity.* 41. If in Mathematics we can thus deal with trans- cendentals without peril to the exactness of our deduc- tions, the question arises whether in other sciences and even in Metaphysics the same procedure may not be * Thus, although we may be wholly unable to answer the question, " What is the result of adding 5x to 7x 1 " so long as x remains without an assigned or assignable value, we are absolutely certain that the sum will be 12# whatever value x may have. On this point let EULER be cited. " On rencontre quelquefois des fonc- tions algebriques dont on ne peut donner une valeur absolue et degagee. ^est une fonction de cette nature de z, si Z se trouve dans une equation de ce genre Z & = azz Z 3 bz *Z 2 + cz 3 Z 1 ; mais quoi qu'on ne puisse pas resoudre cette equation, il est clair cependant que Z est egal a une certaine expression de z melee de constantes, et que ainsi Z est une fonction de z Quant aux fonctions trauscendantes il est a remarqiier qu'une fonction est de cette nature lorsque non seulement 1'operation transcendante y entre, mais qu'elle affecte encore la variable ; car si les operations transcendantea appartinment aux seules constantes la fonction n'en sera pas moin alge- briques." Introd. at Analyse des infinimcnts petits, p. 4. 42 PROBLEMS OF LIFE AND MIND. adopted with similar effect My purpose is to show that this procedure can be followed ; and that in all inquiries, unexplored remainders must be eliminated, and our deductions be confined to the known functions of these unknown quantities. The profitless discus- sions upon Space and Time have been profitless, be- cause of the non-recognition of the transcendental ele- ments and their consequent separation from the positive elements. What is Time ? This philosopher holds it to be an objective existence, which must be accepted as ultimate. Another holds it to be a purely subjective Form of Sense. A third says it is a Form of Sense because it is a Form of Things. Others are fascinated by Lagrange's definition of it, " a fourth dimension of Space." Mathematicians are content with Newton's conception of it as a fluent whicli has no variable fluxion, the only independent variable which " flows equally without regard to anything external and by another name is called Duration." * Without pausing to choose between these concep- tions, or to trace the genesis of the abstraction and its relations to the concretes it expresses, we simply note that each conception leaves something indeterminate, none accurately conveys all that is meant by Time. A mystery always remains unexplained, unexplorable. Let this be granted, let the presence of a transcendent element be insisted on, how you will, the truth is that in the only use we ever make of the conception of Time i.e., in its known functions the measurement ofin- * NEWTON : Principle, ; Scholium to tJie Definitions. " This conception of time as the one absolute and independent variable is undoubtedly one of the most splendid and fruitful in the history of human thought." Prof. ROBERTSON SMITH : On Hegel and the Metaphysics of the Fluxional Calculus. Transactions of the Royal Society of Edinburgh, xxv. 495. SCIENTIFIC METHOD IN METAPHYSICS. 43 tervals this transcendent disappears, the mystery vanishes. "Whatever Time may be, the intervals, which are all we deal with, are equal or unequal, and our equations are rigorously exact. 42. It is the same with Space. Whether we are to regard it as an entity, or an abstraction, is a question for Psychology. What Space is may be left undeter- mined. The vulgar imagine it to be pure Nothing which nevertheless does mysteriously contain all things, holding them like a vessel. They speak of it as of an infinite air-pump, empty of all contents. They do not ask themselves what need Being has of Non-Being to contain it, what need Existence has for another Existence in which to exist. The psychologist may be called upon to explain the genesis of such conceptions, but Science and Practice detach themselves from such puzzles, and without endeavouring to lay hold of the transcendental element in Space, are content to measure spaces with rigorous precision.""" 43. Matter and Motion, Force and Cause, have also their transcendental elements, and it is the province of Metaphysics to demarcate these from the known and knowable elements. Character, again, involves many incalculable elements, organic, historic, social ; yet this does not prevent our comparison of one character with another, or with the different manifestations of one character under different conditions. Vitality, again, * " Absolute Space in its own nature without regard to anything exter- nal remains always similar and immovable. Relative Space is some movable dimension or measure of the absolute spaces, which our Senses determine by its position to Bodies. Because the parts of Space cannot be seen or distinguished from one another by our Senses, therefore in. their stead we use sensible measures of them." NEWTON : Principia ; Sclwlium to the Def. 44 PROBLEMS OF LIFE AND MIND. presents certain aspects which if only from their spe- ciality must always distinguish organic from inorganic existence. Although many vital phenomena have been assigned to physical and chemical conditions, there still remain unexplored remainders after all our analysis. These we may assign either to some special Agent, the supposed vital Force, or to some special Agency, some peculiar combination of physical forces, not yet deter- mined. Whichever hypothesis we adopt, the presence of the transcendental need in no way disturb the ac- curacy of our calculations, if we deal with it properly, and eliminate it from the equations. We may compare one vital phenomenon with another, or with its condi- tions, as we compare one sphere with another, or any one function of an unknown quantity with another ; and the comparison may yield exact results, although we remain eternally ignorant of the excluded elements. 44. The initial defect in transcendental Philosophy and all metempirical inquiry, is not the admission of transcendental elements * as facts and mysteries, but * KANT designates by transcendental that which is anterior to all Experi- rience ; transcendent, that which is beyond all Experience. The words thus respectively stand for a priori and metempirical. Denying the transcend- ence of the mental forms which KAXT assumes, I use the words transcend- ental and transcendent according to their mathematical analogies. " Toute fonction inatheniatique," says the philosophical mathematician COURXOT, "qui ne se trouve pas comprise dans la definition des fonctions alge- briques est reputee transcendante." Traite des Fonctions et du Calcul infinitesimal, 1841, i. 24. That is to say, whatever cannot be expressed in the terms of the science is transcendental to that science : Biology containing phenomena not expressible in terms of Physics, is transcenden- tal to Physics ; and Sociology is transcendental to Biology on similar grounds. Whatever is Suprasensible cannot be expressed in terms of sensible Experience, and is therefore transcendental to Experience metem- pirical. But whenever by any means what is now transcendental becomes expressible in terms of Experience it will thereby cease to be metem- piricaL The term transcendental therefore designates not only that SCIENTIFIC METHOD IN METAPHYSICS. 45 the admission of them among the calculable elements; and the supposition that by means of guesses and constructions in which these incalculable data enter as components, man can reach a higher truth than is attainable through Experience. It will indeed be urged by metaphysicians that although the transcen- dental elements are not calculable from data furnished by Sense and Understanding, they are directly knowable and calculable through the so-called Vernunft, or Intellectual Intuition, which deals with them as Under- standing deals with the data of Sense. I do not pause here to consider this argument which will occupy us further on, but continue my exposition of the Method by which metaphysical problems may be treated with- out the assumption of any such special faculty for the discernment of the transcendental. If I can succeed in extricating such questions from the confusion which results when two diametrically opposite Methods are employed, and if I can thus confine the metempirical Method to the metempirical aspects of each question, it will then be time to examine the pretensions of the Intellectual Intuition. 45. Our first step then is to state each question in such a way that the " unexplored remainder " is dis- engaged from the positive and speculative aspects, and carefully kept apart as a transcendental, not allowed to enter into the equations. The second step is the analysis by which we ascer- tain whether this unknown quantity is to be accepted which can never be brought within the range of Experience, owing to the constitution of things, but also that which cannot at present be so brought, owing to the condition of our knowledge : it is the unexplorable remainder and the unexplored remainder. 46 PROBLEMS OF LIFE AND MIND. as an ultimate fact, a fiction or a phrase. We inquire, 1, whether it is ultimate, as in itself beyond analysis, incapable of reduction to some more general fact ; 2, whether it might possibly be analysed were certain data secured ; but, these not being secured, we make a provisional guess, throwing out some hypo- thesis which, if correct, would link the phenomena into intelligible unity ; 3, or failing even this speculative aid, we adopt a phrase which, although explaining nothing, serves at least to baptise the unknown, and is thus often of advantage (sometimes the reverse) in keeping under one rubric phenomena which have essential points of similarity along with manifold differences. 46. These three modes of dealing with the unknown quantity may be thus exemplified. A biologist having ascertained that organic phenomena always require special combinations of oxygen, carbon, hydrogen, and nitrogen for their basis, and are never found where these are absent, accepts the ultimate fact of Vitality dependent on this combination. It is a fact no more explicable by reduction to some other fact, than why the ratio of f is the ratio of i or A. The fact is so ; is observed to be so ; why it is so admits no further answer (for the present) than that whatever is is. 46a. The speculative biologist is dissatisfied, and thinks this dependence may be explained by the intro- duction of an Agent, visible to his speculative eye. He creates the fiction of a Vital Principle, which no one has seen, which no one can connect with positive data ; and endows it with whatever properties are needed for the results observed. He invents an Im- ponderable, a Force, which has the power of fashioning SCIENTIFIC METHOD IN METAPHYSICS. 47 the Ponderable, which can select and combine phy- sical and chemical elements, and can animate lifeless matter. We see that this is a fiction ; but we do not on that account reject it. Fictions are potent; and all are welcome if they can justify themselves by bringing speculative insight within the range of positive vision. What then must be our attitude with respect to this Vital Principle ? We must submit it to all the tests by which hypotheses are controlled, tests which while allowing the freest scope to the energy of Imagination prevent that energy from degenerating into licence. This fiction has been tested, and has proved a failure : it explains nothing. Nevertheless it has left behind it a convenient phrase ; and now positive biologists are quite ready to speak of Vital Force, or the vital forces, as brief ways of designating phenomena. There is indeed always danger in thus appropriating the phrases of rejected fictions : the danger lest insufficient vigilance allow the phrases to be interpreted in their old mean- ings ; and an immense service to Science would be effected by some notation which would always accom- pany hypotheses and hypothetic phrases a sort of al- gebraic x, keeping alive our sense of the presence of an unknown quantity." 3 ' 47. The metaphysical problems of Matter, Force, Cause, Law, Soul, &c., likewise present elements posi- tively known, elements speculatively knowable, and elements that lie beyond all reduction to Experience, positive or speculative. The novelty of the procedure * FOXTENELLE charmingly says : " fl faut etre presentement sur ses gardes pour ne pas lui imaginer quelque realite : on est expos^ au peril de croire qu'on 1'entend." Eloge de Newton. 48 PROBLEMS OF LIFE AND MIND. followed in this work consists in treating these pro- blems on the same Method as that followed in Science, first separating the three aspects, and then seeing how far inductions will carry us. No one can have studied the history of physical investigation without seeing that progress has been mainly effected by the habit of more or less con- sciously eliminating from each question the metem- pirical aspect. It is strikingly manifest in the labours of Galileo and Newton, when compared with those of Kepler and Descartes. But in instituting this comparison we must guard against the common confu- sion of the speculative with the metempirical point of view ; a confusion explicable enough when no sharp definition of the metempirical had been given. It i* a serious error to imagine that the true scientific spirit is opposed to the speculative, because it is opposed to the metempirical. The error arises partly because the Logic of Speculation has not yet been organised with sufficient precision, its tests and canons are left un- disciplined; hence because Speculation is conterminous at one side with Metempirics, it has frequently been carried by its ardour over its own lawful boundaries into that nebulous region where all tests fail ; and thus the speculative thinker is regarded with distrust by positive thinkers. Nor is the distrust surprising, when we see the discordant mingling of unprovable fictions with provable conjectures in the writings of even such splendid workers as Kepler and Descartes. 48. To confirm our vindication of the speculative procedure, it is enough to glance at the labours of the two supreme positive inquirers, Galileo and Newton. Illustrious judges have declared that Galileo's concep- SCIENTIFIC METHOD IN METAPHYSICS. 49 tion of the laws of Motion is his greatest achievement/' 5 ' If we examine his famous dialogue we find that it is mainly theoretical : experiment is rarely invoked, though everywhere implied. Let us, he says, conceive the simplest and most perfect rule, and we shall form the most probable hypothesis. If we follow out the consequences of this rule, and express them in mathe- matical theorems, we may do so without peril. " Geo- metry has already studied numerous curves never met with in reality, and detected in them wonderful pro- perties ; and to geometry our conclusion also will belong even if experiment is unable to confirm them." Here there is an explicit announcement of the deepest con- ception of scientific Method, and the conjunction of the principle of Ideal Construction (on which see PEOB. I. chap, v.) with the principle of Sensible Verification. The separation and co-operation of the speculative and positive points of view could not be more clearly stated. Galile'o knew that such a conception as Velo- city was ideal ; and that the proportionality between the velocity of a falling body and the time of its fall could never be directly verified in experiment ; but he knew also that it could be indirectly verified through consequences accessible to observation and experiment. His laws of Motion would have been speculatively true, like those of geometry, even could they never have * Thus LAGRANGE, speaking of the discovery of the Composition of Motions, says that although during his lifetime it brought him less celebrity than his astronomical observations, " elle fait aujourd'hui la partie la plus solide et la plus reelle de sa gloire. Les decouvertes des satellites de Jupiter, des phases de Venus, des taches du soleil, &c., ne demandaient que des telescopes et de 1'assiduite ; mais il fallait un genie extraordinaire pour demeler ces lois de la nature dans des phenomenes qu'on avait toujours eus sous les yeux, mais dont 1'explication avait neanmoins toujours echappe aux recherches des philosophes." -Mecanique Analytique, 1811, p. 221. VOL. I. D 50 PROBLEMS OF LIFE AND MIND. received positive verification ; and I snail hereafter show that they are only rigorously true in the region of Ab- straction, and are not true of actual motions. 49. The reader was perhaps somewhat incredulous on finding Newton cited as an example of speculative greatness. The veneration which consecrates the name of Newton has so far failed to dignify his practice, that the simple characterising of that practice wears the air of paradox. Was he not the ideal of a positive thinker \ Did he not protest against Speculation ? It is true. But although Newton's language is sometimes directly counter to his practice, and is vitiated by the mis- placed alarm which he shared in common with all the reformers of that day, at the chaotic consequences of speculative ingenuity, this was mainly due to the ab- sence of a clear discrimination between speculative and metempirical inquiry. At any rate, it is the fact that Newton's glory is founded quite as much on the purely speculative as on the purely positive part of his labours ; while nearly all his popularity, outside the mathemati- cal circle, is due to it. He who declared that he made no hypotheses insisting that they could have no place in experimental philosophy has raised his name out of the very small circle of mathematicians, where he must ever occupy a glorious position, into its leader- ship among philosophers, by virtue of his splendid speculative insight, the daring keenness of his venture- some imagination in creating hypotheses. It was an hypothesis, and a daring one, by which he instituted the Infinitesimal Calculus, introducing velocities, under the name of Fluxions, whereby the correlative values of two variables were supposed to increase together. The element of Velocity was as pure an hypo- SCIENTIFIC METHOD IN METAPHYSICS. 51 thesis as the element of Ether in the explanation of Light, or of Electricity* or Nervous Fluid in the explanation of Neurility : it was, moreover, an accessory hypothesis an artifice, not an inference. Again, his identification of celestial and terrestrial motions was an hypothesis ; so was the extension of gravitation be- yond the solar system ; an hypothesis his conception of the attraction exercised by spherical bodies on a point beyond or within their spheres ;'* an hypothesis his conception of attractive and repulsive forces similar to positive and negative quantities in Algebra, the former vanishing where the latter begin ; an hypo- thesis that Motion is constantly destroyed, and conse- quently that the universe requires active Principles, " such as the cause of gravity, by which planets and comets keep their orbits, and bodies acquire great motion in falling ; and the cause of fermentation by which the heart and blood of animals is kept in con- stant motion and heat;" an hypothesis that Light con- sists of corpuscles emitted from the luminous source ; an hypothesis that "the Senses are not for enabling the soul to perceive the species of things in its sensorium, but only for conveying them thither," these, and several other queries propounded in the Optics, are surely strange contradictions to the often-quoted and much- misunderstood hypotheses non Jingo ? 49a. It may be objected that some of these hypo- theses he himself brought so near to demonstration that they have taken place among established truths, and that they were legitimate constructions on mathemati- cal principles. This does not alter their speculative character. And while we know that some of his * Comp. POINSOT : Elements de Statique, 5th ed. 66. 52 PROBLEMS OF LIFE AND MIND. illustrious contemporaries regarded these hypotheses as revivals of a scholastic spirit, rejecting Attraction because it was an occult quality,"' we also know that Science which has accepted some of the hypotheses has ?ecognised others as non- verifiable, and some as false, nay even absurd. Be this as it may, our purpose is simply to recognise the large latitude given by this mighty investigator to the operation of that speculative imagi- nation which he is commonly supposed to have dis- credited. In this connection it is piquant to observe that in the very passage which follows his famous denunciation of hypotheses, he has no hesitation in propounding a view which in these days must startle the most speculative by its wildness : "And now we might add something concerning a most subtle Spirit which pervades and lies hid in all gross bodies ; by the force and action of which Spirit the particles of bodies mutually attract one another at near distances, and cohere if contiguous ; and electric bodies operate to greater distances, as well repelling as attracting the neighbouring corpuscles ; and light is emitted, reflected, refracted, inflected, and heats bodies ; and all sensation is excited, and the members of animal bodies move at the command of the will, namely, by the * HUYGHENS and LEIBNITZ, so eminently qualified to comprehend the mathematical theory of attraction, rejected it as unworthy of examination. In writing to LEIBNITZ before he had seen the Principia, HUYGHENS says : " I am anxious to see Mr Newton's book. I am content at his not being a Cartesian provided always he does not thrust forward such suppo- sitions as that of attraction." After having read the book he says : " The explanation of the cause of reflux of the tides does not in the least satisfy me, nor all those other theories which he founds on his principle of attraction, a principle that seems to me absurd. I am amazed to see any one taking so much trouble and entering into calculations so elaborate founded on such a principle." See BERIKAND : Les Fondateurs de C Astronomic Moderne, 311. SCIENTIFIC METHOD IN METAPHYSICS. 53 vibrations of this Spirit, mutually propagated along the solid filaments of the nerves from the outward organs of sense to the brain, and from the brain into the muscles. But these are things that cannot be explained in few words, nor are we furnished with that sufficiency of experiments which is required to an accurate determination and demonstration of the laws by which this electric and elastic spirit operates." 50. In presence of evidence like this one may well ask, What meaning is to be attached to the famous dictum, and what is the vindication of Newton's practice which so obviously departs from that dictum 1 The answer is that Newton had thoroughly grasped scientific Method ; and his magisterial superiority is nowhere more lucent than in its clear and careful distinction between the positive and speculative aspects of each question. The positive part of his work always consists of geometrical and dynamical facts and deduc- tions. The precision and reach of this are uncontested, incontestable. Then comes a speculative part, brilliant, seductive, and peculiarly acceptable, because it fulfils the primary condition of affording facilities to calcula- tion. But this part is always questionable, hypothetical. Observe how clearly he separates these very different aspects in the declaration which opens the exposition of the system of the world in Book III. " In the preceding books I have laid down the prin- ciples of philosophy, principles not philosophical but mathematical; such, to wit, as we may build our reason- ings upon in philosophical inquiries. These principles are the laws and conditions of certain motions and powers or forces, which chiefly have respect to philoso- phy. But lest they should have appeared of themselves 54 PROBLEMS OF LIFE AND MLN'D. dry and barren, I have illustrated them here and there with some philosophical scholiums, giving an account of such things as are of more general nature, and which philosophy seems chiefly to be founded on." And towards the close of the general scholium he says : " Hitherto we have explained the phenomena of the heavens and the sea by the power of gravity, but have not yet assigned the cause of this power. ... I have not been able to discover the cause of those pro- perties of gravity from phenomena, and I frame no hypotheses. ... To us it is enough that gravity does really exist, and act according to the laws which we have explained, and abundantly serves to account for all the motions of our celestial bodies and our sea." From this alone it would be evident that he did not, as is often said, discourage inquiries into the cause of gravity, but simply discouraged the facile and illusory explanations which were constructed out of arbitrary suppositions, instead of out of observed phenomena, " Physics beware of Metaphysics," was his warning. He was ready enough to speculate as to the cause of gravity, but well knew that his speculations were mere gropings in the dark, not to be placed beside the posi- tive principles he had so laboriously brought to bear on the facts observed. The cause, whatsoever it might be, he declared was an active Principle, not an occult quality supposed to result from the specific Forms of Things, but one of the " general Laws of Nature " by which the things themselves are formed ; " their truth appearing to us by phenomena, though their causes be not yet discovered. For these are manifest qualities, and the causes only are occult. And the Aristotelians gave the name of occult qualities not to manifest qual- SCIENTIFIC METHOD IN METAPHYSICS. 65 ities, but to such only as they supposed to lie hid in bodies, and to be the unknown causes of manifest effects : such as would be the causes of Gravity, and of magnetic and electric attractions and of fermentations, if we should suppose that these forces or actions arose from qualities unknown to us, and incapable of being discovered and made manifest. Such occult qualities put a stop to the improvement of natural philosophy, and therefore of late years have been rejected. To tell us that every species of things is endowed with an occult specific quality by which it acts and produces manifest effects, is to tell us nothing. But to derive two or three general Principles of Motion from phenomena, and afterwards to tell us how the- properties and actions of all corporeal things follow from these manifest Princi- ples, would be a very great step in philosophy, though their causes were not discovered." * In the preface to the Principia he says : " For all the difficulty of philosophy seems to consist in this from the phenomena of Motion to investigate the forces of Nature, and then from these forces to de- monstrate the other phenomena. And to this end the general propositions in the first and second books are directed. In the third book is given an example in the explanation of the System of the World. For by the propositions mathematically demonstrated in the first book, we there derive from the celestial phenomena the forces of Gravity with which bodies tend to the sun and the several planets. Then from these forces by other propositions, which are also mathematical, we deduce the motions of the Planets, the Comets, the Moon, and the Sea. I wish we could derive the rest of * Optics, Book III. subfinem. 56 PROBLEMS OF LIFE AND MIND. the phenomena of Nature by the same kind of reasoning from mathematical principles. For I am induced by many reasons to suspect that they may all depend upon certain forces by which the particles of bodies by some causes hitherto unknown are either mutually impelled towards each other and cohere in regular figures, or are repelled and recede from each other ; which forces being unknown, philosophers have hitherto attempted the search in vain. But I hope the principles here laid down will afford some light either to that or some true method of philosophy." And again, towards the close of the Optics, he says : " As in Mathematics, so in Natural Philosophy the in- vestigation of difficult things by the method of analysis ought ever to precede the method of composition. This analysis consists in making experiments and observa- tions, and in drawing general conclusions from them by induction, and admitting of no objections against the conclusions, but such as are taken from experiments or other certain truths. For hypotheses are not to be re- garded in experimental philosophy. And although the arguing from experiments and observations by Induc- tion be no demonstration of general conclusions, yet it is the best way of arguing which the nature of things admits of, and may be looked upon as so much the stronger by how much the Induction is more general. And if no exception occur from phenomena, the con- clusion may be pronounced generally. But if at any time afterwards any exception shall occur from experi- ments, it may then begin to be pronounced with such exceptions as occur. By this way of analysis we may proceed from compounds to ingredients, and from mo- tions to the forces producing them; and in general from SCIENTIFIC METHOD IN METAPHYSICS. 57 effects to their causes, and from particular causes to more general ones, till the argument end in the most general." This, then, was Newton's doctrine, and it was also his practice in general ; although he sometimes so far forgot his own principles that he allowed theological and metempirical elements to mingle with the induc- tions of Experience. 51. The reader has already seized my drift, which is that Metaphysics can be pursued on the Method of Science, provided it accepts all the tests and conditions of that Method, and keeps within the range of Expe- rience. Thus treated, its dangers and difficulties would be no greater than those of Science, its certainties would have the same foundation. In both we have to disen- gage the known and knowable from the unknown and unknowable ; and having disengaged the known quan- tities, we proceed to operate on them in the detection of the unknown. In every problem we have to deter- mine 1, Is there a known Agent or Agency, which will furnish the answer "? 2, By what operations can the presence of this be made manifest ; by what testa can we assure ourselves that the Agent is the one which we have assumed, or that this Agency has the requisite law, or order ? 52. Now the common error of metaphysicians, and one not uncommon also among men of science, is hastily to assume an unknown Agent or Agency, or to assume the presence of one known, and then to operate on that assumption as on a solid basis. There is one aspect in which such a procedure is perfectly legitimate namely, when it is avowedly conducted as a tentative hypo- 58 PROBLEMS OF LIFE AND MIND. thetical mode of establishing an equation, afterwards to be verified when the values are assigned. The pro- cedure is fatal when this artifice is forgotten, and is made to solve the problem without verification of the assumed values. The geometer resolves his problem by deriving the properties of the figure from those already known and analogous ; having before him the laws to which the several parts of the system con- form, he deduces from these the quantities sought, and thus constructs his figure. To obtain his equation he assumes the problem to be already solved, and constructs a figure according to the hypothetical state of the known and unknown quantities. Thus, so far from dispensing with Hypothesis, the geometer largely invokes its aid, only he never forgets the nature of the aid invoked. He is mostly guided by probabilities, which he intends reducing to certainties ; he anticipates by divination what is afterwards to be reached through demonstra- tion. The chief distinction between his probabilities and those of the physicist or biologist, lies in the greater simplicity or unequivocalness of his terms, and the consequent greater facility of their verification. Some- times he finds his construction leads to a nugatory solu- tion, and he here sees that the hypothetical figure does not agree with the question, and that somewhere some contradictory conditions have been introduced. In this case he constructs another, invoking fresh hypothesis, and thus he tries one after the other, until he hits upon that which will satisfy the equation. 53. The procedure of the physicist is similar. He constructs a hypothetical scheme of the dependent parts of the phenomenon from those already known, and by processes of Verification ascertains whether this scheme agrees with Observation and Deduction. If he SCIENTIFIC METHOD IN METAPHYSICS. 59 has introduced into the scheme contradictory con- ditions, or has left out conditions that are co-operant, the discrepancy between Observation and Calculation warns him of his error ; and he tries another scheme. Although the task of Verification is usually more arduous and delicate than in Geometry, it is essen- tially the same. Dealing as the physicist does with data which are more complicated, less accurately de- finable, and dependent on minute and numerous obser- vations and inductions, he is more easily led to accept a complex condition for a simple one, and to disregard conditions which seem insignificant because he is not alive to their significance. 54. If the physicist is thus hampered, still more are the biologist, psychologist, and metaphysician hampered, because their data are excessively complex, and their definitions fatally equivocal. Yet their Method should be the same. Could they pursue it with the same rigorous regard to its tests and canons, their results would be as exact as those of the physicist and geometer. The common notion of the exclusive supe- riority of what are called the exact sciences I hold to be an error. There is always an admitted inaccuracy, or incompleteness, in every geometrical solution^ except in the region of Abstraction i.e., ideal construction; and in that region, the solutions of Biology or Meta- physics may have equal accuracy. In Mathematics, which consists of operations on symbols, the exactness is ideal ; when the results thus obtained are applied to reality they are approximately true in as far as the symbols express real terms; but mathematical opera- tions may be equally exact when their symbols are avowedly unreal; and it has been possible to in- genious geometers to construct a non-Euclidian geo- 60 PROBLEMS OF LIFE AND MIND. metry, on the assumption that Euclid's postulate is false. Hence ws may conclude that Metaphysics, con- sisting of operations on symbols of Force, may be equally exact, and their results approximately true in regard to reality, the degree of approximation depending on the reality of the terms. The presence of trans- cendent elements need not disturb us. Every physical problem involves metempirical elements beside those which are empirical ; but Physics sets them aside, and dealing only with the empirical, reaches conclusions which are exact, within that sphere. No disturbance in the accuracy of calculation follows from the existence, outside the calculation, of elements which are incal- culable. The law of gravitation, for example, is exact, although its transcendental aspect namely, what gra- vitation is in itself, whether Attraction, Undulation, or Pressure is not merely left undetermined, but by the majority of physicists is not even sought. The law of Association of Ideas is equally exact, although not quantitatively expressible. The dependence of Sensa- tion upon Stimulus is .not less so, and has received a quantitative expression/" The laws of Causation may be formulated with equal precision. And exact know- ledge of Force, Cause, Matter, ought to be attainable, in spite of their transcendental elements, by the one procedure of eliminating these, and operating solely on the empirical. Hence the conclusion : The scientific canon of excluding from calculation all incalculable data places Metaphysics on the same level with Physics. * The ratio of the increase of a sensation to the increase of its stimulus is that of a logarithm to its number. FECHNEH : Psychophysik, 1860. Bd. ii., p. 11. CHAPTER IV. OBJECTIONS TO METAPHYSICS. 55. THE Method just sketched in outline must be exhibited in practice through the subsequent chapters. What has already been said purports only to show that Metaphysics is possible under certain limitations which apply to all Science ; and under this programme may be included everything that is rational in the persistent effort of mankind to solve certain problems, while at the same time firm hold is kept of that Method which alone has rewarded effort. " Tout est permis au philosophe," says Maupertius truly, " pourvu qu'il traite tout avec 1'esprit philosophique." All problems are open to the metaphysician, provided he treat them on scientific principles. All ? Yes, all that can be brought under the conditions and limitations which regulate research. But problems which cannot be so treated are idle and mischievous. 56. There has probably arisen in the minds of some readers a feeling of uneasy distrust, aod in others a feeling of surprise, at finding me advocating the study of Metaphysics. " Timeo Danaos " will be the remark of the former. " He has relinquished the Positive Philosophy," will be the remark of the latter. The first suspicion I cannot remove. The second may be 62 PROBLEMS OF LIFE AND MIND. easily answered. Keferring to what was said in 5, I may add that the exclusion of all metempirical ques- tions, and the rejection of the metempirical Method, is the cardinal position of the Positive Philosophy ; which also admits much of what is here called Metaphysics,' namely, the highest generalisations of the several sciences, though it excludes the problems of Matter, Force, Cause, Life, Mind, Object, and Subject. Why does it exclude these ? Simply on the ground of their being insoluble, metempirical. But this rejection seems to me somewhat arbitrary, when the state of the case is examined ; and inj udicious, when we find that it not only irritates those who might be convinced, but irritates them by a misconception. All who put their trust in the Positive Philosophy must regret that it should alienate instead of alluring speculative thinkers, capable of extending its reach ; and it alienates them by the supercilious assertion that they are, and have been, wandering on the wrong path ; which may be true, is true ; but which would be better enforced by pointing out their point of divergence from the right path, so that their steps might be retraced. Nor can the appeal to History suffice ; at the utmost it can only be somewhat of a reductio ad dbsurdum, a procedure which even mathematicians now agree to regard as O O cumbrous,* since it constrains assent in lieu of enlight- ening conviction, and is therefore inferior to demon- stration. Instead of a supercilious negation, or unsatis- factory historical refutation, it will surely be a gain if the problems are admitted, and shown to be soluble on the positive Method. 57. The grounds of opposition to metaphysical in- *SeeDuHAMEL: Cours d? Analyse, 1841, i. 3. SCIENTIFIC METHOD IN METAPHYSICS. 63 quiries may be grouped under two heads : 1, that they move in a world of Abstraction regardless of concrete realities consequently their solutions can never be more than purely subjective constructions without objective validity; 2, that they seek to penetrate Causes and Essences, which are necessarily unknowable. There is truth in both objections, as applied to the common practice of metaphysicians ; but we have only to rectify that practice by a more rational statement of each question, and the objections fall away. For nothing is more clearly demonstrable than that what is called exact Science is also a purely ideal construction, dealing primarily with abstractions, and not with con- crete realities ; so that the valid objection against any system of Metaphysics is not that it moves in a world of ideal conceptions, but that its conceptions have been illegitimately constructed, or illogically applied. Fur- ther, I shall hope to show that the search after Causes, nay, efficient Causes, is the aim of Science, and that the aim is attainable. But to understand this it is necessary that we set out with a clear conception of what it is we seek, and how it may be found : the search after Causes is futile or fertile accordingly. In like manner, according to the meaning assigned to the term, there will be a truism or a falsism in the common declaration that the human mind is incapable of knowing the Essences of things. A traditional perversion makes the essence of a thing to consist in the relations of that thing to something unknown, unknowable, rather than in its re lations to a known or knowable i.e., assumes that the thing cannot be what it is to us and other known things ; but must be something " in itself," unrelated, or having quite other relations to other unknowable 64 PROBLEMS OF LIFE AND MIND. things. In this contempt of the actual in favour of the vaguely-imagined possible, this neglect of reality in favour of a supposed deeper reality, this disregard of light in the search for a light behind the light, meta- physicians have been led to seek the " thing in itself " beyond the region of Experience. To reflective minds it was early apparent that such a qucesitum was a phantom ; and because it could not be grasped, they declared, not that this phantom-essence was beyond our reach, but that all essences were impenetrable mysteries. With the reality before them they declared it was a phantom, and that the shadow was the reality, the essence ! 58. No wonder if questions thus inappropriately con- ceived were condemned to remain without answers. Were a mathematician asked : What is the essential colour of a circle ? . he would reject the question as not geometrical The circle has no colour. But any circu- lar figure may have any colour, and that colour is essen- tial to it. Were a physicist asked : What is the nature of the emotion felt by a mass when undergoing mole- cular change ? he would reject the question as not physical. Emotion does accompany certain molecular changes, but as far as we know this is only under very special conditions, and the phenomenon lies wholly beyond the province of Physics. But if such questions can receive no answer, because not put in answerable terms, how much more so the questions which avowedly travel quite beyond all range of Experience, and ask : What is the thing in its relations to something unknown ? To know a thing is to know its relations ; it is its relations. Therefore to ask : What are its re- lations to an unknowable ? is absurd. SCIENTIFIC METHOD IN METAPHYSICS. 65 59. Under this bias men declare, truly enough, that Metaphysics belongs to a condition of culture from which Europe has finally though with immense difficulty emerged ; a condition in which men instead of interrogating Nature, please their fancy with try- ing to discover the general character of Being in the abstract. Bui; although there is truth in the contemp- tuous phrase designating Metaphysics as the pursuit of ontological chimeras ; and it is the conviction of this which has caused metaphysical study to be abandoned ; there is also truth in the rejoinder that Metaphysics may be fruitful although the efforts of metaphysicians have hitherto been failures ; and it is the conviction of this which sustains inquiry among the valiant few. 60. What is our position in this controversy ? It is that there is Ontology, and Ontology : il y a fagots, et fagots. There is Ontology pursued on the Metempiri- cal Method ; and this, like all inquiries so pursued, is necessarily fruitless. There is Ontology pursued on the Empirical Method, and this is Abstract Science, which is occupied with the general laws of Being. A moment's consideration will make this clear. What is the ob- ject of each science \ It is to detect the general order of Things, as manifested in particular groups of pheno- mena : i. e., the abstract laws of Being under particular conditions. It is not moving bodies in all their complex relations, but laws of Motion ; not living organisms, but laws of Life; not thinking organisms, but laws of Mind it is these which are the objects of Science ; and the particular substances, plants, and animals which manifest such laws, are used only as stepping-stones to reach those higher points of view. The reproach, if it be a reproach, conveyed in the term " ontological " when VOL. i. E 66 PROBLEMS OF LIFE AND 3OXD. applied to Metaphysics, is shared by Science. In both, the search is after abstract Being, not after concrete individual fact. Rightly understood there is troth in saying that a metaphysician may have a knowledge of Being as certain as the mathematician's knowledge of Magnitude, as the chemist's knowledge of Affinity, as the biologist's knowledge of Life, as the sociologist's knowledge of Society ; and this knowledge may be gained in the same way. 61. By way of illustration consider the positive science of Crystallography, and presently it appears that the mineralogist is studying the abstract Crystal, its geometrical laws and its physical properties. He constructs this abstract conception out of data furnished by many individual minerals ; but although these are necessary stepping-stones, they and all their individual characters disappear, leaving only the general charac- ters common to all; from these is obtained the abstract conception, The Crystal. Xow when the mineralogist expounds the principles of his science he is obviously dealing with the laws of abstract Being exemplified under the special conditions of crystallography. It is the same with the biologist ; in expounding the laws of Life he is dealing with Ontology. The crystal does not exist as a phenomenon ; neither does the animal ; they are ideal creations, and in this light may stand be- side the entities of the Schoolmen, or the oirog o*> of the Eleatics ; but although the ancient and the modern On- tologies are alike ideal creations, they differ profoundly in their construction ; the one is seen to be incapable of a reduction to sensible experience, the facts are not resolvible into assignable factors ; the other is seen to be only an abbreviated symbolical expression of the SCIENTIFIC METHOD IN METAPHYSICS. 67 ' observable order in things. The constructions of the ancients admitted metempirical elements beside the empirical, and endowed possibilities with the value of realities ; they differ from those of positive Science as fallacies and paralogisms differ from facts and syllogisms. 62. There is then a rational and an irrational Onto- logy, an empirical and a metempirical Metaphysics. It is wholly a question of the manner in which the abstrac- tions are formed, and not of the degree of abstractness. The scientific acceptance of Laws and Properties is quite as metaphysical as the scholastic acceptance of Entities and Quiddities ; but the justification of the one set is their objective validity, i.e., their agreement with sen- sible Experience ; the illusoriness of the other is their incapability of being resolved into sensible concretes. So nearly are the two allied that many an incautious scientific speculator treats the Laws precisely as the Schoolmen treated Entities ; and thus we so often see a Law supposed to rule the phenomena, as if from the outside ; and the Property of a substance is often an ill - disguised Quiddity. The current notions about Force are as irrational as anything to Jbe found in Scholasticism. 63. With this rectification of the prejudice against Ontology, which is one with that against Metaphysics, we may say that understanding by Ontology the science of the abstract laws of Being, it is the science of those highest generalities which emerge from the study of Things, and there can be no difference between Science and Metaphysics except in the degrees of generality. In other words every science has its metaphysic ; and our definition of empirical Metaphysics (we recognise 68 PROBLEMS OF LIFE AND MIND. no other) will be "the science of the most general principles." This definition resembles that of Aristotle in its terms, though of course widely different in its meaning. Thus conceived, Metaphysics holds a posi- tion with respect to Science somewhat analogous to the position held by Algebra with respect to Arithmetic. The objects of Arithmetic are quantities ; the objects of Algebra are not quantities but the relations of quantities. In like manner the objects of Science are the laws of sensible phenomena ; the objects of Metaphysics are not these, but laws of the laws : the Calculus of opera- tions. Although dealing with the generalities of gene- ral principles, as the Transcendental Analysis deals with relations of equations, the equations having been fur- nished by Algebra, and the values by Arithmetic, Metaphysics must not be otherwise detached from the grounds and limitations of Experience. Unless its general principles have been securely established by Science, its operations will be as chimerical as those of a Calculus of imaginary equations ; and unless its operations be verifiable they will be worthless. Its point of departure and its point of arrival must be Reals. All its intermediate positions may be far re- moved from sensible reality, nay, considered in them- selves, they may be impossible as Reals, provided they re-enter the domain of Reality, and conduct us to our goal : that is all we ask of any operation. When we desire to reach the summit of a mountain whose sides are too steep for ascent, we may quit the firm earth, and trust ourselves to the yielding air, if a balloon be ready to carry us through it. The result justifies the means. Most of our scientific operations have this airy character. But there are others, and all metem- SCIENTIFIC METHOD IN METAPHYSICS. 69 pirical hypotheses are of this class, which instead of the balloon furnished by Science, and proved to be effectual, call upon the poet's Hippogrif, and hope by it to be carried through the air. They never reach the summit. 63a. Metaphysics then, as we often say, comes after Physics, does not precede but follows the establishment of relations. From the laws of the Cosmos discovered by Science it elicits certain general relations, which are then visible in phenomena, just as the theory of Gravi- tation originated by inductions from terrestrial physics, was confirmed by inductions from celestial physics, and when thus established was afterwards reflected back on terrestrial physics, disclosing unexpected relations there. This reflected light discloses unsuspected equations; and is always regulative of Research. The conception of what is called the Correlations of Force, or more suitably the Transformation of Energy, is a metaphy- sical conception, and has led to the discovery of unsus- pected relations. The relation of Function and Organ, although a biological law, could hardly have been es- tablished except as a deduction from the metaphysical conception first gained through Mechanics, and then seen to be universal I mean the relation of Dyna- mic and Static. Thus between Science and Meta- physics there is a constant give and take. And this give and take we find between sensation and idea, induction and deduction, particular experiences and general Experience; and it is itself a luminous example of the metaphysical Law of Polarity, which we shall hereafter have to consider as the expression of that Two- fold Aspect under which all Experience presents itself. Not to anticipate more than is absolutely needful here, I will content myself with suggesting that Expe- 70 PROBLEMS OF LIFE AND MIND. rience has two grand divisions : the Cosmos, or Object- world, and the Consciousness, or Subject- world. Both are subdivided into Static and Dynamic aspects. The Cosmos is conceived as Existence, and as Cause : Exis- tence is the static aspect of Cause ; Cause is the dy- namic aspect of Existence. The Subject- world is conceived as Organ and Function. The relations of Object and Subject which Psychology discovers are carried up into the region of Metaphysics, as the rela- tions of the Cosmos are ; that is to say, they remain strictly matters of Science while restricted to particular divisions, and become matters of Metaphysic when they are extended to several or all divisions. But this point we must discuss in the next chapter. CHAPTER V. THE PLACE OP METAPHYSICS AMONG THE SCIENCES. 64. HAVING agreed that Metaphysics, or the science of the highest generalities, is possible, we may now inquire whether it should be detached from the sciences which severally furnish those generalities, and be erected into a separate Discipline (to use the German term) just as there is a separate Discipline of Logic formed out of the several logics ; or whether, in conformity with Comte's classification, Metaphysics should not be thus detached, but distributed among the sciences from which its data are drawn. Mr Mill has objected to Comte's scheme, in relation to Logic, that while furnishing an organon of Discovery it omits the organon of Proof, so that the ancient Disci- pline finds no place assigned to it. The answer to this objection is that in point of fact the organon of Disco- very includes the organon of Proof; to discover a pro- cess is to prove it; and the several sciences furnish their own methods of Proof. But it may still be urged that Comte's scheme does not exhibit the extraction of these methods and their systematisation in a special Discipline. He seems to have had some misgiving on this point when, in his latest work, he proposed to identify Logic (in its restricted sense) with Mathe- 72 PROBLEMS OF LIFE AND MIND. matics; although by Logic in its widest sense he meant all intellectual construction. In the former sense, he identifies it with the Calculus, Geometry and Mechanics, because the sole existence which is common to all ap- preciable beings is reducible to the three attributes number, extension, and movement/''' 65. Let us pause a moment to consider the very dif- ferent meanings assigned to the word Logic. It com- monly stands for: 1, the art of reasoning; 2, the theory of reasoning ; 3, Eeasoning itself ; 4, the laws of mental operation, irrespective of the symbols ope- rated on (Formal Logic) ; 5, the rules of Proof. The first of these I hold to be absurd. There is no more an art of Reasoning than there is an art of Breathing, or Digesting. But so little is this under- stood that even thoughtful writers will be found de- claring that we must learn how to reason, as we learn how to fence or to swim. In consequence of this mis- conception, certain studies, notably Mathematics, are popularly believed " to strengthen the Faculty," to develop the logical powers, to "invigorate the Judg- ment." The psychological notions which lie at the basis of such declarations are sadly defective, The second and third meanings of the word are objectionable because restricting Logic to the process of Ratiocination when the ratios are abstract. This re- striction is got rid of in the fourth and fifth meanings, which may be accepted as comprehensive. The fourth designates the universal Logic, it includes all Laws of Grouping (Xeyew means to bind together, to group), and is therefore applicable to Feeling and Thought (in the subjective world), and to Cause (in the objective world). * COMTE ; Synthese Subjective, p. 71. SCIENTIFIC METHOD IN METAPHYSICS. 73 The fifth has the technical and restricted meaning of a Codification of the rules of Proof . In this last sense only can Logic be a separate Discipline. It may be likened to the science of Grammar apart from Lan- guage. Thus the speech of men of various nations embodies and exhibits certain general rules, or tenden- cies, according to which words are grouped. These tendencies grammarians detach and treat separately as Laws of Speech, Rules of Grammar. Logicians may in like manner detach certain general procedures of the investigating intellect, and treat them apart as the Rules of Rational Inquiry. 66. Having fixed on the meaning Logic may bear when employed for a special Discipline, namely, the Codification of the rules of Proof, we may complete it by assigning to Metaphysics the parallel position of a Codification of the laws of Cause. It will thus occupy very much the place assigned to it by Hegel, namely, that of Objective Logic. The Object and the Subject world have one general Logic, separately viewed as the Logic of Intelligence, and the Logic of the Cosmos. In the Cosmos, viewed objectively, things influence each other and events succeed each other according to inva- riant tendencies, or laws. When these phenomena are reproduced in Consciousness they are also reproduced according to invariant tendencies ; and thus it is that a law of Cause becomes a rule of Proof. Logic in its widest sense is Grouping. The laws of Grouping are the general tendencies of Things and the general tendencies of Thought. The common separation of Thought from the Things thought of, is an artifice : but it is one so deeply inwoven with our philosophy and practice that the mind, untutored in such re- 74 PROBLEMS OF LIFE AND MIND. searches, is astonished and distressed at the statement of the identity between Thing and Thought, Object and Subject With what qualifications this statement has to be received we shall hereafter discuss. Here I am only concerned to define the position of Metaphysics as Objective Logic the Codification of the most abstract laws of Cause. The subjective Logic takes no account of the special instruments and processes by which each science reaches Proof, it is occupied solely with the codification of the processes. In like manner the ob- jective Logic disregards special details in the processes of Causation, solely occupied with codifying the most abstract results. Subjective Logic rejects whatever lies beyond the range of Verification, and thus de- marcates Reality from Possibility, Fact from Fiction. Objective Logic rejects whatever lies beyond that world of sensibles and extra-sensibles which can come within the range of Experience; and thus demarcates Meta- physics from Metempirics. 67. This distinction between the two aspects of Logic represents the distinction between Knowing and Being ; and the identity underlying this diversity is also represented. In one we find the laws of Investi- gation, the abstract conditions to which all knowledge is subject In the other we find the laws of the In- vestigated, the abstract conditions to which the Know- able is subject. Only on the assumption of the invari- ability of relations objective and subjective is Philo- sophy possible. In the most abstract of the sciences, that of Number, this identity is manifest No arith- metical operation would be valid were there not this accord between the internal and external ; and the assumption of such an accord runs throughout Science. SCIENTIFIC METHOD IN METAPHYSICS. 75 Indeed the axioms of Logic and the axioms of Science are the concave and convex aspects of the same curve.""" 68. The Positive Philosophy may in one sense be said to absorb Metaphysics, for it claims to be the Codifica- tion of the laws of the Cosmos. Nor, except as a mat- ter of special classification, should I have any objection to this, were it not accompanied by the peremptory exclusion of certain questions which can and must be answered. And with respect to the classification there is precisely the same difficulty with Logic. Comte in- sists that Logic should never be separated from Science : " Car en n'etudiant chaque partie de la methode induc- tive qu'avec les doctrines qui Tont specialement suscitee, on sent aussitot que son usage doit etre conforme aux notions fondamentales que cette science regoit de la pre'ce'dente." t True and valuable as this consideration is, there are nevertheless several considerations which justify the erection of Logic as a special Discipline ; and these equally apply to Metaphysics. There are many speculative advantages in having the highest generalisations of Objective and Subjective existence classed together and apart from the sciences which fur- nish them. When Logic is seen to embrace both, * Since this was written Mr SPENCER has propounded a new view of Logic. Starting from the position that the syllogism refers to the depen- dencies of Things and not of Thoughts, he comes to the conclusion that Logic must be carried over entirely to the Object- world. He therefore places it beside Mathematics as it is placed in COMTE'S latest scheme. He holds that " it formulates the most general laws of correlation among existences considered as objective." Eeferring the reader to Mr SPENCER'S exposition (Psychology, ii. 302 et seq.}, I will merely here add that my chief divergence from it arises from my inability to accept his conception of there being only a symbolic correspondence between the inner and outer worlds. I hope to make it clear that the correspondence is real. t COMTE : Politique Positive, i. 518. 76 PROBLEMS OF LIFE AND MOD. under its twofold aspect, the ancient barrier between Matter and Mind so long regarded as impassable vanishes, to reappear under the intelligible forms of concave and convex. Idealism is vindicated in all that it has of truth, and Realism is rescued. The Inner and Outer forms of Consciousness, the Subjective and Objective forms of Existence are no longer antagonistic, but homogeneous and differentiated. 69. The identity of Fact and Idea^ general Law and general Conception, is more readily appreciated in the higher sphere of Reason than in the lower spheres of Perception, because in the higher sphere the Object seems detached from Sense and is transformed into pure Thought Thus in investigating the processes of Induction and Deduction we abstract these operations from their sensible elements, we let drop all the min- istrations of Sense and fix attention solely on the mechanism of Thought ; by a similar abstraction the mathematician detaches Extension from Matter and Motion from Solidity, although perfectly aware that pure Extension and pure Motion are impossible in the concrete. But no one believes that inductive and de- ductive processes can go on without at every step in- volving sensible correspondences. So long as we are observing and calculating the changes in objects, our conception of these changes as taking place in the objects, and not in us, is fixed, undisturbed. The objective aspect is the aspect presented to Conscious- ness. But no sooner do we pass from the observation of the changes to the conception of their Law, than the distinction between Conception and Law begins to fade : we recognise that the Law is not in the facts but in our minds : if we elicited it from the facts we SCIENTIFIC METHOD IN METAPHYSICS. 77 constructed it anew, and replaced it among the facts. Whether this construction is to be regarded as an objective Law or a subjective Conception depends on our point of view : it is both, or either. 70. This will seem very unacceptable to those, and they are the majority, who imagine that phenomena are ruled by law in a literal sense, and who think that laws exist in the objective world as general facts which determine particular facts. It is thus that, in Pindar's phrase, the very Gods are subject to law, like mortals : No/ioj 6 vdvruv j rs xoti udavdruv, And if the Gods, of course the fleeting phenomena. And yet we may hear utterances of this kind'- " The comets follow no law in their motions through space " which simply means that no conception has been formed by astronomers of all the determining conditions, and by them placed among the facts observed of the planetary courses. The purely ideal construction of Law will hereafter be expounded (PnoB. I. chap, vi.), suffice it here to say that it throws no uncertainty over the results of inves- tigation. The conception we form of a process in Nature may be no less accurate as a symbolical ex- pression of the reality, than the perception we form of an object in Nature is an accurate sensible expression of the reaction of Consciousness under the stimulus of the object, and of what that reaction will be under all similar conditions. Both conception and perception are logical constructions, and are verifiable by similar tests. 71. If Laws are simply our Conceptions, and these are the Notations of what Experience has revealed to be the 78 PROBLEMS OF LIFE AND MIND. Order in which phenomena coexist and succeed each other, it is clear that Idealism demands a basis in Keal- ism, and that our Conceptions to be valid when re- garded objectively as Laws, must be capable of reduc- tion to a sensible origin, each of their constituent elements must be a real experience, and the order of their combination must be real. If we find among the constituents any element not thus reducible to Sense or to Intuition, that element must be set apart and treated as a transcendental. Thus treated, there need be no misgiving as to its part in the construction, nor as to the certainty of the results reached through that construction. The identification of Law with Concep- tion will by no means warrant the too common proce- dure of metaphysicians who endeavour to explain the Order in Things, by unfolding an Order in Thought, and propound theories of the Universe which rest mainly on the " clear ideas " whose genesis is not in- ductively verifiable. It is quite possible to have very clear ideas which are inexact expressions, and very logical arrangements which do not conform to the Order of Experience. Although Science constantly anticipates Observation by a far-reaching Deduction, and reveals hidden facts by simply unfolding the con- sequences shut up in general conceptions, this is only possible when the general conceptions have been framed from and express actual relations and thus include what is deductively concluded. Because they are con- ceptions which were abstracted from realities, they can in turn be applied to all similar realities. Tangents, sines and cosines are not things found isolated in Nature, but because they are abstractions from realities, they are applicable to Nature. No one observing a SCIENTIFIC METHOD IN METAPHYSICS. 79 curvilinear motion can see in it the double motion in the tangent to the curve and towards the centre of the o curve no one in watching a beam of light can see the slightest indication of what the geometer finds there (or places there), viz., that the luminous vibrations are perpendicular to the line of propagation; in other words, that each vibration takes place at each instant on the surface of a sphere which has for its centre the point from which the ray diverges. Tangents, centres, vibra- tions, perpendiculars these are constructions of the intellect, not facts of sensible concretes. Yet such constructions are by no means arbitrary, they are all reducible to Sense and Intuition, they all conform to rigorous objective tests ; and because they are so, and because objectively found to reconcile Calculation with Observation, they are stamped upon phenomena as laws. Is it necessary to add that although every law is a con- ception, every conception is not to be accepted for a law ? It is necessary, because we frequently overlook the dis- tinction, and give out the forms of our own fancies for forms of phenomena. There is an order in our sensa- tions, and an order in our thoughts ; but even these orders do not always coincide. There is further an order in things on which the order in sensations and thoughts depends. But the dependence is particular that is to say, the order in our sensations will depend on the momentary order in things, but this may or may not be an order which is general. Now it is only the general order in things with which Philosophy is con- cerned, and which is expressed in laws; particular events are evanescent and only interest the moment ; Philosophy seeks to frame conceptions which represent the Order in things, not at one instant and under par- 80 PROBLEMS OF LIFE AND MIND. ticular exceptional conditions, but at all times and under varying conditions. Such conceptions obviously cannot be framed irrespective of particular experiences, but they must nevertheless be abstracted from particu- lars and represent what is common to all.* 72. What has been already said will perhaps suffice to justify confidence in the recognition of Metaphysics as a possible branch of Science. For what constitutes a science ? The co-ordination of facts. By what charac- ters may it be recognised ? A science exists, 1, when it has a clearly defined object; 2, when it has a clearly defined place in the region of research, a place not oc- cupied by any other; and 3, when it has a clearly- defined Method of applying the results of Experience to the extension of experience, All these characters are recognisable in Metaphysics Its object is the disengagement of certain most general principles, such as Cause, Force, Life, Mind, &c., from the sciences which usually imply these principles, and the exposition of their constituent elements the facts, sensible and logical, which these principles involve, and the relations of these principles. Its place, as a special Discipline, is that of an Objective Logic. Its method is that of dealing exclusively with the known functions of unknown quantities, and at every stage of inquiry separating the empirical from the metempirical data. * " Toute science consiste dans la coordination des faits ; si les diverses observations etaient entierement isolees, il n'y aurait pas de science. On pent raeme dire generalement que la science est essentiellement destinee a dispenser, autant que le comportent les diverses phenomenes, de toute observation directe, en permettant de deduire du plus petit nombre pos- sible de donnees immediates, le plus grand nombre possible de resultats. N'est ce point la 1'usage reel, soit dans la speculation soit dans 1'action des lois que nous parvenons a ddcouvrir entre les phenomenes naturels ? " COMTE : Philosophic Positive, i. 131. 31 73. It may be expected that most metaphysicians will accept our premisses, but with a reserve which will cause them to reject our conclusion. They will proclaim that what is here called Metempirics is equally the co- ordination of facts ; and they will urge that the range of facts to be co-ordinated, and the Method of co-ordi- nation is unwarrantably restricted to the facts of Ex- perience, and the procedures of positive Science. The facts which we declare to be unknowable, they affirm to . be knowable and known. The debate on this point can only be settled by an analysis of Knowledge, and agreement as to its necessary limitations. We shall therefore have to treat this at length. And with regard to Method they urge that what is usually understood as Science cannot fitly grapple with the highest problems of Metempirics, because, dealing only with the particular and contingent, it cannot rise to universal and necessary truths cannot pass into ' the field behind phenomena. 5 This also we shall have to debate. Without venturing here to assume that every reader will find me expressing his conclu- sions on these two deeply interesting points, I am content to rest my case on the indisputable ground occupied by both schools, namely, that whether we have, or have not, a class of facts which transcend Expe- rience, and a special organ the so-called Intellectual Intuition by which such facts may be apprehended and co-ordinated into a system, there still remains that marked separation indicated in the terms Metaphysics and Metempirics ; and hence I affirm that the only fruitful procedure in the treatment of metaphysical problems is the disengagement of their metempirical elements. VOL. I. F 82 PROBLEMS OF LIFE AND MIND. 74. Kant tells us that a rational theory of Nature only deserves the name when its laws are d priori and cannot be gained through Experience ; indeed only be- comes rational in proportion as it admits of mathe- matical treatment. This is plausible if we accept his unacceptable definition of Experience, his emi- nently questionable view of d priori truths, and his assumption that Mathematics has not an empirical origin. Fichte consistently declared that all natural laws, from the law by which a blade of grass will grow to the law which keeps the planets in their orbits, might be deduced from first principles.* The deduction was attempted : and whoever desires to see with what result, may open Oken or Hegel. Closely connected with this reliance on the d priori procedure is the sig- nificant fact that every metaphysical thinker, who pre- tends to bring a contribution towards the explanation of things, has his own personal system, and would be offended by any accusation which implied the contrary. Nay, it is a boast that " Philosophy is not to be learned like Mathematics, or like a trade." Each philosopher holds himself independent of fellow-workers, like an artist expressing his individual conceptions. Hence Fichte can truly say, "the kind of Philosophy which a man chooses depends upon the kind of man." Con- trast this with Science. Who would think of choosing his astronomical or biological system? who would speak of Faraday's Physics, or Liebig's Chemistry, as he speaks of Kant's Psychology, and Hegel's Logic ? Absurd as it is, this notion of a personal choice in Philosophy is very common, and finds its analogue in the personal choice of a Religion. Consistently with this there is a * FICHTE : Werke, i. 64-5. SCIENTIFIC METHOD IN METAPHYSICS. 83 demand on the part of the public that the philosopher's system should sustain the Theology and Polity of his age and nation. The public which insists, and rightly insists, on an artist's not outraging the taste and moral convictions of his audience, is consistent in demanding a like conformity to prejudices and doctrines on the part of the philosopher, if that philosopher desires recognition for his system as an individual conception. Schelling was justified in declaring that a system of Philosophy which contradicted the moral feelings could never be a system of Reason but only of Unreason. * But he omitted to add the qualification, namely, that men too readily assume their own personal views to be those which cannot be contradicted without con- tradiction of the moral consciousness. Unless Philo- sophy be an Art, and wholly personal, we must agree with Kant that there is something preposterous in demanding enlightenment from it, and at the same time prescribing the opinion it is to enforce. 75. Philosophy, like everything else, is evolved from pre-existing conditions, and the novelty of any valid system should consist in supplying some missing links, or in formulating some unformulated evidence, thus extending and systematising the known. When, there- fore, I claim novelty for the conception of applying to Metaphysics the procedures consciously and uncon- sciously applied by men of science in all successful investigation, I do not mean that the conception is now for the first time originated, but that now for the first time it is definitely expressed in its principles and bearings. Many have thought, and some few * SCHELLING: Werke, vii. 413. 84 PROBLEMS OF LIFE AND MIND. have proclaimed, that Metaphysics should be based on facts, and its problems resolved on the principles of Experience. But no one to my knowledge has explicitly stated hoiv this was to be effected. After all, the question of originality is of quite minor importance ; that of efficiency most concerns us. Con- vinced that all germinal conceptions are the product of their age rather than of any individual mind, I should look at any conception of mine with extreme suspicion if it wore the air of other novelty than that of added precision or of extension ; for, as De Morgan feli- citously remarks in tracing the discovery of the Differ- ential Calculus, "A great method is always within the per- ception of many before it is within the grasp of one." 76. Is it not a justifiable hope that, by applying the Method of Science to all questions, England may some day possess a Philosophy, the absence of which during the last two hundred years has been a serious defect in her culture? Science, she has had, and Poetry, and Literature, rivalling when not surpassing those of other nations. But a Philosophy she has not had, in spite of philosophic thinkers of epoch- making power : Hobbes, Locke, Berkeley, Hume, have produced essays, not systems. There has been no noteworthy attempt to give a conception of the World, of Man, and of Society, wrought out with sys- tematic harmonising of principles. There has not been an effort to systematise the scattered labours of isolated thinkers. Mr Herbert Spencer is now for the first time deliberately making the attempt to found a Philosophy. While no one can deny that there has been this deficiency, many will declare it to have been an advantage. In some respects it was. So long as SCIENTIFIC METHOD IN METAPHYSICS. 85 i the ground was unprepared for a stable edifice, the collection and sifting of the materials was the best work to be done. In other respects the disadvantage has been palpable. Philosophic research has lost itself in out-of-the-way corners. It has never placed itself on a height from which a wide view of the universe could be had. This was inevitable, because its Method isolated it from Science. With our Philosophy, as with our Politics, the parochial point of view has supplanted the cosmopolitan. The same spirit which manages the affairs of the Nation too much through Parish Boards, forgetting that the Nation is an integrant part of the living world, has parcelled out the Universe into ' Sec- tions ' of a British Association, and from those sections has carefully excluded not only Psychology, Ethics, Metaphysics, and Religion, but anything wearing the aspect of a general doctrine embracing all research. 77. In this respect Germany has had an advantage which has outweighed the serious evils of a radically false Method. The habit of philosophising that is, of taking general views, and connecting special truths with them has become, so to speak, organised in the German mind ; and its influence on culture has been highly beneficial. It percolates the soil, and is felt even when metaphysical problems are not directly touched on in the treatment of History, Language, Politics, Criticism, &c. No doubt this has its drawbacks. Our parochial system will sometimes be favourably con- trasted with the results of their world-system ; some- times also unfavourably. Our system has kept closer to reality; theirs has oftener been allured by phantoms. We shook off Scholasticism, they retained it. But in shaking it off we also shook off the speculative passion 86 PROBLEMS OF LIFE AND MIXD. for nice accuracy of distinction, and for wide general conceptions ; and they, now that they have learned to look more closely at realities and trust less in logical legerdemain, still retain the old love for systematic and exhaustive treatment. The German Philosophy of recent years has become more and more infused with the scientific spirit. 78. In conclusion, I may here simply state my con- viction that the Philosophy, in the construction of which the efforts of all nations converge, is that Posi- tive Philosophy which began with Kepler and Galileo, Descartes and Bacon, and was first reduced to a system by Auguste Comte : the Doctrine embracing the World, Man, and Society on one homogeneous Method. The extension and perfection of this Doctrine is the work of the future. The following pages are animated by the desire of extending positive procedures to those outlying questions which hitherto have been either ignored, or pronounced incapable of incorporation with the positive doctrine. Kant asks : " If Metaphysics is a science, how comes it that she cannot boast of the general and enduring approbation bestowed on other sciences \ If she is no science, how comes it that she wears this imposing aspect, and fascinates the human understanding with hopes inextinguishable yet never gratified \ We must either demonstrate the competency or incompetency; for we cannot longer continue in our present uncertainty."* The answers to these questions which Kant gave not having been satisfactory, a new attempt, under more favourable conditions, is made in these pages. To render this attempt satisfactory we must first clearly * KAXT : Prolegomena zu finer jeden kiinftigen Metaphysik : Einlei- tung. SCIENTIFIC METHOD IN METAPHYSICS. 87 understand the conditions of metaphysical inquiry. The initial condition that of separating the insoluble from the soluble aspects of each problem would be accepted by all. But the question would everywhere arise : What is insoluble? How is this ascertainable ? There are problems which are recognised as insoluble because of their conditions. For example, it is impos- sible to extract, the square root of a number which is not made by multiplication of any whole number or fraction by itself. To all eternity this must be impos- sible. Yet an approximation is possible which may be made near enough for any practical purpose. There are other problems again which do not admit of even approximative solutions. No one really tries to solve what he is already convinced is an insoluble problem. But one man thinks the problem soluble which another pronounces not to be soluble. What then is our cri- terion 1 We say the metempirical elements must be thrown out of the construction. But what are the metempirical elements ? Here we find ourselves fronting the great psycho- logical problems of the Limitations of Knowledge, and the Principles of Certitude. To settle these it will be necessary to examine the pretensions of the d priori school. Our first labour then will be to examine the principles of positive and speculative research, and then to show that the principles of metempirical research must either be unconditionally rejected or if accepted must be isolated from all departments of Knowledge and restricted solely to the Unknowable. By way of introduction to these, and to the prob- lems which will succeed, it -may be useful to group together in an accessible form the principal Rules of Philosophising which ought to regulate our efforts. IXTRODUCTIOX. PART II. THE RULES OF PHILOSOPHISING. AT the opening of his Third Book, Newton sets forth the Rules of Reasoning in Philosophy, which in Eng- land have been generally accepted with an almost unquestioning reverence. Yet Newton himself never professed them to be exhaustive ; and indeed, as Whe- well remarks, they were obviously constructed with an intentional adaptation to the case with which he had to deal namely, the induction of universal gravitation and are meant to protect the reasonings before which they stand. It is not strange, therefore, that, when considered under other aspects, these Rules should prove to be defective both in precision and in range. Whewell has criticised them without hesitation. Instead of criticising, or defending them, I here propose certain Rules which, while including those of Newton (with such modifications as may bring them into closer accord- ance with my views), will serve also by their wider range to protect the reasonings which will follow in the course of this work. There may be some temerity in deviating from Newton, for it is with Newton as with THE RULES OF PHILOSOPHISING. 89 Shakespeare, the genuine reverence of the Few has become stiffened into the superstition of the Many; and the formalism of superstition is always outraged by a suggestion of dissent. Men who have seldom or never turned over the leaves of the Principia are exas- perated when they hear that any one who has studied and been strengthened by that work, ventures to hint at flaws in it. Never having slaked their own thirst at the Holy Well, they hear with impatience of drinkers who presume to reject the weeds and dead leaves which float in its pure water. Newton is not, however, directly here in question. What the following Rules profess is no more than certain general results of philosophic reflection on the conduct of Research, which are offered to the attentive medita- tion of the student. RULE I. No problem to be 'mooted unless it be pre- sented in terms of Experience, and be capable of empirical investigation. REMARK! The proper statement of a question often carries with it the answer. When the answer is not at once con- spicuous, a proper statement limits the field of search by disengagement of the unknown elements, Avhich are then examined in order to determine whether, 1, they are unknown, and unknowable because metempirical ; or, 2, they are unknown only because the requisite conditions of knowledge lie beyond our present data. In the former case research ceases. In the latter case it proceeds, and is guided by the following rules : 90 PROBLEMS OF LIFE AND MIND. KULE II. Any contradiction of fundamental expe- riences of Sense or Intuition to be taken as evidence of some flaw either in the data or the calculation. REMARK. This seems a truism, yet it is a rule fatally disre- garded, partly owing to impatience, which leads men to accept even logical contradiction rather than remain without an explanation ; partly to the conviction that many of the most certain results of science seem in contradiction with ordinary experience. But in truth what seems a contradiction proves to be due either to the contradictory mode of statement, or to an erroneous inference from experience ; sometimes it is the substi- tution of a prejudice or tradition for experience. The Eule simply asserts that since the direct ex- periences of Sense and Intuition (the perception of objects, and the perception of the relations of objects) have the highest possible validity, and form the basis and the test of all Demonstration, they cannot be con- tradicted by any real .deduction from them; so that, whenever our deductions or hypotheses involve this logical inconsistency, it is the indication of something somewhere wrong. Does the error lie in our assuming that the experience we declare to be fundamental is direct, whereas it proves by analysis to be indirect, derivative, and possibly imperfect ? Critical examina- tion must decide. The question must be reduced to its components. Thus the old opinion respecting the sun's revolution round the earth seemed to be a funda- mental experience which Copernicus contradicted. It was nothing of the kind. It was an inference from THE RULES OF PHILOSOPHISING. 91 experience ; and what the Copernican hypothesis con- tradicted was not the visible fact, but the inference respecting the invisible cause of that visible fact. Al- though we believe that the earth revolves round the sun, and that this motion has the effect of making the sun seem to describe the circle, yet what we see is not the motion of the earth, and for most practical purposes the old hypothesis is still employed. The application of this Eule requires great tact and accurate knowledge. It is violated in many theories which have gained a wide acceptance, and its value is great in keeping the mind open to new evidence, and warning us that any conclusion which violates it must be wrong. The notion of " action at a distance," which still finds energetic defenders, could never have gained acceptance had this Rule been clearly recognised. EULE III. " The qualities of bodies which admit neither of intension nor remission of degrees, and ivhich are found to belong to all bodies within the reach of our experiments, are to be esteemed the universal qualities of all bodies." REMARK. This is Newton's Third Rule. On it he remarks : " For since the qualities of bodies are only known to us by experiments, we are to hold for universal all such as universally agree with experiments, and such as are not liable to diminution can never be quite taken away. "We are certainly not to relinquish the evidence of experiments for the sake of dreams and vain fictions of our own devising; nor are we to recede from the 92 PROBLEMS OF LIFE AND MIND. analogy of Nature, which uses to be simple and always consonant to itself. . . . We no otherways know the extension of bodies than by our senses, nor do these reach it in all bodies ; but because we perceive exten- sion in all that is sensible, therefore we ascribe it to all others also. And this is the foundation of all philosophy." Professor Challis calls this a golden rule. Whewell speaks slightingly of it ; and indeed it accords ill with his system. To me it seems absolute, if taken with the qualification involved in Rule X. When we gene- ralise experience, and conclude what will be from what has been, it is obvious that our justification rests on the assumed homogeneity of the terms : the event predicted must be of the same nature as the event observed, otherwise the Rule cannot be fitly applied. RULE IV. No Agent to be admitted unless it have a sensible basis ; nor any Agency unless it be veri- fiable or calculable. REMARK. This relates chiefly to Hypothesis, It permits the adoption of any conjecture as to Agent or Agency, provided such conjecture facilitates calculation. But so lonor as the verifiable nature of either is uncertain, o * the conjecture must be kept apart from all the posi- tively ascertained data, and rigorously shut out from the final conclusion. In other words, the solution of an equation must always express the unknown quantity in terms of the known quantities ; and every interpretation of a phenomenon must be the interpretation of it in terms of Feeling. THE RULES OP PHILOSOPHISING. 93 RULE V. " We are to admit no more causes of natural things than such as are both true, and sufficient to explain the appearances." REMARK. This is Newton's First Rule ; and, though not ex- pressed with perfect precision, is pregnant with wisdom. The objection may be raised that, inasmuch as causes avowedly not true can gain no acceptance, the whole question turns on the validity of the causes invoked. What is a vera causa ? Newton obviously means by it an Agent or Agency already known to exist, and seen to be sufficient to account for the phenomena if its presence be admitted. Whewell objects that if we never look for a cause except among those already familiar, we shall never become acquainted with any new cause. This objection misses its mark. New Agents or Agencies, when discovered, may be seen to be the causes of phenomena hitherto unexplained ; but to attempt to explain by unknown causes is futile ; and the Rule is directed against this very futility. Curiously enough, Newton himself in his remark on the Rule violates it : "To this purpose the philosophers say that Nature does nothing in vain, and more is vain when less will serve ; for Nature is pleased with sim- plicity, and affects not the pomp of superfluous causes." Now who shall say that Nature doing nothing in vain is a 'true cause/ or that Nature's 'pleasure' can be known ? The Rule is important by its exclusion of unknown causes, and by its correction of the tendency to mul- tiply causes. We often find philosophers dissatisfied with an explanation which is sufficient, and seeking 94 PROBLEMS OF LIFE AND MIND. additional causes among data that are not given but assumed for the purpose. They fail to recognise that when we have discovered the law of a series, the form of a function, we have reached the limit of research. RULE VI. Each cause must always and everywhere have the same effect ; and never more than this. REMARK. This will be much disputed, owing to the wavering interpretation assigned to the idea of cause. We often hear that different effects arise from the same cause, and that every cause has many effects : in this way Indiges- tion is said to be the effect of overwork of the brain or the effect of eating raw apples. This is utterly un- scientific. Owing to the current laxity of conception even Newton has expressed himself timidly on this point in his enunciation of the Rule : " Therefore to the same natural effects we must as far as possible assign the same causes." The unalterable rigour of the canon is necessary to the integrity of the conception of every phenomenon, every process, every law. All experience, all science would be a mere sand-heap without it. If the same cause could have different effects, or even slightly vary- ing amounts of the same effect, prevision would be impossible. What we call the different effects, are the differences resulting from new combinations of causes. When I come to treat in detail the Problem of Cause, it will be made clear that whether we speak of complex or of simple phenomena there must necessarily be at least two factors for every product ; hence if we sum up the factors in the term Cause, and name the product THE RULES OF PHILOSOPHISING. 95 Effect, it is obvious that the Effect is always the Pro- cession of its Cause: the dynamical aspect of the statical conditions. Not to enlarge on this point here, let us only remark that the Rule reminds us that no verified fact can be contradicted by any other fact : each has its own intrinsic validity. When two observations seem con- tradictory, or when the same facts present two different aspects to two observers, this is an indication of some alteration in the conditions, either of the fact itself, or of the observer's position. Under the same conditions phenomena are unalterable. We may also see that no process can destroy another, although it may be so compounded with it that the resultant of the two will present a different aspect from that of either of the components. Causes, like motions, may be superposed, each acting independently; or combined, each acting as a factor : but whether super- posed or fused each cause is invariant ; it is only the phenomena that are variable. Hence RULE VII. No proof can be valid beyond the range of its data; no conclusion is exact which shuts in what is not included in its premisses. REMARK. The violation of this is seen when conclusions reached in one department of phenomena are extended to de- partments wherein their premisses are not the only premisses. Although each science throws its light on every other, owing to the interdependence of pheno- mena, and the community of Consciousness, yet no science can be controlled by the results of another, and this because phenomena are independent not less than 96 PROBLEMS OF LIFE AND MIND. interdependent. Mathematics cannot receive laws from Chemistry, nor Physics from Biology ; the phenomena studied in each are special. But underneath the special differences there are interdependences, com- munities, whereby mathematical laws enter into che- mical and biological explanations, physical laws into chemical, and chemical into biological. These laws are absolute at their points of intersection but not beyond. That is to say, the mathematical law is absolute for the mathematical relations of the physical, chemical, or biological phenomenon ; but not beyond ; and so of the others. The validity of each vanishes with its limit. In the development of an ovum, for instance, it is demonstrable that physical and chemical laws are in- volved, and that these are absolute in their order ; but more than these are involved, since by none of the laws hitherto detected in operation among inorganic pheno- mena is it possible to explain the biological laws of Nutrition, Evolution, Reproduction, and Decay. Should Molecular Dynamics one day be in a position to furnish such a deduction (which is probable), there would still remain the speciality of organic phenomena dependent on a speciality of concurrent causes, which would con- tinue to separate biological from physical and chemical laws. RULE VIII. Because the significance of a phenomenon lies wholly in its relation to other phenomena we must never isolate it from this relativity, and draw conclusions respecting it per se. REMARK. It is the constant error of metaphysical speculation to attempt a real distinction corresponding with the THE RULES OF PHILOSOPHISING. 97 analytical distinction of a thing from its relations. The thing is its relations, and although analytically we may separate them, attending now to this relation, now to that, we must never imagine the separation to be real. EULE IX. We are not to conclude the properties of elements from the properties of the groups they form ; nor vice versa. REMARK. This, which is the direct consequence of Rule VIIL, although obvious enough in many cases, often requires delicate tact in application. No one commits the mis- take of supposing that either of the elements of water has when separate the properties of water; no one supposes that the properties of each element combined in water could be deduced from the observed properties of the combination ; no one supposes that from the ob- served properties of oxygen and hydrogen, separately considered, the properties of water could be deduced. Yet analogous mistakes are often committed. Many philosophers assume that atoms, or the ultimate ele- ments of Matter, must have the properties observed in masses ; and still more assume that the properties, of an object belong to it apart from the subject, not as elements of the combined object-subject, but as qualities of the thing per se ; while still greater is the number of those who assign to one factor in a causation the character noted in a result due to several factors. Every mathematician knows that there are number- less theorems true of integers which are not true of the fractions, the properties of the fractions often widely differing from the properties of the integers. VOL. I. 98 PROBLEMS OF LIFE AXD MIST). The mistake here pointed out often arises from not discriminating between component parts and consti- tuent dements. What is true of the mass is generally true of any part of that mass, the difference being only quantitative. A molecule of water has the properties of a gallon of water. But even this is true only of those properties not directly dependent on quantity : for experiments on finely-divided substances show that many a substance begins to lose its molar properties in becoming molecular, since some of the effects which depend on the individual molecules, and which in the mass were mutually balanced, then begin to manifest themselves, the balance being disturbed. The distinction here indicated between Components and Constituents, or between Parts and Elements, will be seen hereafter to have its importance. All quanti- tative relations are componental ; all qualitative rela- tions elemental The combinations of the first issue in Resultants, which may be analytically displayed ; the combinations of the other issue in Emergents, which cannot be seen in the elements, nor deduced from them. A number is seen to be the sum of its units ; a direction of movement is seen to be the line which would be oc- cupied by the body if each of the incident forces had successively acted on it during an infinitesimal time ; but a chemical or vital product is a combination of elements which cannot be seen in the elements. It emerges from them as a new phenomenon. THE RULES OF PHILOSOPHISING. 99 EULE X. The validity of conclusions rests on the preservation of homogeneity in the terms and the identity of their ratios. REMARK. This extremely important Rule we shall often have to invoke. It will be brought prominently forward in the discussion of Necessary Truths. One of the com- monest sources of error is that of unconsciously changing the terms of a proposition without at the same time making the corresponding change in the ratios. Valid generalisation can only be effected by extending to many or to all what is positively true of some, it being therein assumed, or proved, that the many, or all, do not differ from the some in the characters ascribed. For example, when we generalise from masses to mole- cules, it is like passing from large numbers to small numbers, so long as the molecules are assumed, or proved, to possess all the characters known of masses ; but if we observe and we often do observe that the masses tend to lose their homogeneity in becoming molecular (which is the passage to their heterogeneity in becoming resolved into their constituent elements), our conclusions respecting their properties tend to be- come more and more uncertain. We cannot deduce the relative movements in a system from our observa- tion of the movements of that system the movements of animals from the movement of the earth the rota- tion of the earth from the movements of the solar system ; or, vice versa, the orbital movement of the earth from the relative movements of its bodies. Each problem has its equation of condition ; and it is only by generalising this, that is to say, preserving the homo- 100 PROBLEMS OF LIFE AND MIND. geneity of its terms and ratios, that any conclusion can be established beyond the particular case. EULE XL Science is built up from Abstractions, and these are built up from Concretes. No Abstrac- tion must contain more than is warranted by its Concretes. REMARK. When the Abstraction expresses more than is given in the Concretes, it must be understood as the geometer understands a transcendent; however useful in pre- serving the symmetry of expressions, it must never enter into the final equation. We may employ the abstraction Life to express all the concrete phenomena observed, and the unexplored remainder ; but it is only the former that we must admit into our theoretical explanation : the unexplored remainder must not be treated as if it had been explored and mastered. We may employ a fourth co-ordinate to facilitate calcula- tion, but must never allow this symbol to be mistaken for the sign of a concrete reality. KULE XII. Carefully to discriminate between the abstract or analytical point of view and the con- crete or synthetical point of view. REMARK. Experience is the registration of feelings and the relations of their correlative objects. Science is the explanation of these feelings, the analysis of these ob- jects into their components and constituents, which are then held to be the factors of the facts. These factors THE RULES OF PHILOSOPHISING. 101 i are of various kinds, real and ideal, concrete and abstract, appreciable by Sense, and appreciable by Intuition. Considered subjectively, the real is what is either felt or perceived ; the ideal is what is either imaged that is to say, the feeling reproduced in the absence of its external object or conceived; i.e., the feeling repre- sented in a symbol. The real is what is actually given in Feeling. The ideal is what is virtually given, when Inference anticipates what would be Feeling, were the objective causes in direct relation with Sense. Thus the direct experience of the one is supplemented by the indirect experience of the other : vision is com- pleted by prevision : real observation by ideal construc- tion. No sooner has the construction been verified, all its inferences reduced to sensations, all its inductions to deductions, and its deductions to intuitions (by a process we shall hereafter consider), than ideal factors take the place of real factors, prevision of vision, and the truths of ideal relations are recognised as having the same validity as the truths of real relations, for the ideas are virtual feelings. But the process of verifica- tion is both complex and delicate, so that whenever an ideal relation is inconsistent with the corresponding real relation, and prevision contradicts vision, the error must lie on the side of the ideal construction. The starting-point is always Feeling, and Feeling is the final goal and test. Knowledge begins with in- definite Feeling, which is gradually rendered more and more definite as the chaos is condensed into objects, effected through a rudimentary analysis determined by the fundamental Signatures (Qualities) of Feeling, namely, Tension, Intension, Extension, Duration, Like- ness, Unlikeness. LIBRARY UNIVERPTTY OF CALIFORNIA SANTA BARBARA 102 PROBLEMS OF LIFE AND MIND. Each object is by a subsequent analysis resolved into its components ; these again are resolved into their constituents ; and these in turn into their constituents, if the regressive analysis be practicable or serviceable. Thus water is a real object, a concrete fact of our experience. We learn its properties, and we also learn that it is a mass of molecules, each molecule having the properties of water, and that the weight or force of the mass is the sum of the molecules. Analysis of this mass will resolve each of the molecules into its constituent elements, oxygen and hydrogen gas : these have their properties, not the properties of water, and they have their movements, which are not the move- ments of the molecules. Analysis is still within the region of the sensible, for the water is only the mole- cule ' writ large ' ; but now it takes a further regressive step, and decomposes each molecule of the gases into constituent atoms, or ultimate elements. These are purely ideal. They cannot be presented to Sense, but are presented to Intuition, and are seen by the mind, not as reals, but as logical postulates, symbols to assist calculation. Thus a curve is a real, but the infini- tesimal straight lines into which it is ideally analysed are symbols only, not reals. Analysis is descriptive when it deals with compo- nents, and genetic when it deals with constituents. The one is proximate, sensible, and generally certain ; the other remote, extra-sensible, and liable to error : it is always an attempt to explain the known by the less known, sometimes by the unknown but hypo- thetical, consequently it must always have less validity than the synthesis it is invoked to explain. I mean THE RULES OP PHILOSOPHISING. 103 that a fact must always be more certain than the factors by which we elucidate its origin. Analysis always requires the verification of synthesis. Having taken an object to pieces we cannot be sure that we have in the pieces all the components or con- stituents unless we can, really or ideally, build up again the object from those pieces. The failure to rebuild in- dicates the oversight of one or more of the constituents. KULE XIII. Philosophy, being the harmony between the concrete and abstract, the synthetic and its explanatory analytic, demands that everywhere ike abstract be subordinate to the concrete in respect to validity, though it is superior in point of dignity. REMARK. This is insisting on the subordination of means to ends. The purpose of knowledge being the guidance of primitive Impulses for the satisfaction of Desires, obviously Speculation must be subordinated to the Practice which it is intended to serve ; and all concep- tions of Reason, however lofty, must have perception and action for their final aim : they are intermediates between the feeling which is an impulse and the feeling which is the result of that impulse in action. But although the end is more important than the means, and although Feeling is final, and Thought has only validity in accordance with Feeling, in point of dignity (that is, of governing value) Thought is supreme, and abstract conceptions are of far higher 104 PROBLEMS OP LIFE AND MIND. moment than concrete perceptions. The animal life is higher in dignity than the vegetal ; the social life is higher than the individual. Yet the animal functions depend on the vegetal, the social on the animal. Theories which embody multitudes of relations are more dignified than facts which embody particular re- lations ; but the theories are subordinate to the facts. The Nation is of more importance than any one Family, and the Family than one of its members; neverthe- less the dependence of the Family on its members, and of the Nation on its Families, is absolute. Hence the fallacy must be guarded against which assumes that general laws, or axioms, because of their superior dignity, have a deeper validity than particular truths. Connected with this is the fallacy that laws rule phenomena, determine them ; whereas they only express the phenomena in a formula. One consequence of this fallacy, which has many, is the error of deducing from averages conclusions which are not of average but of particular relations e. g., when the average amount of food consumed by 100 men is taken as the guide for the rations of the in- dividuals, each man being taken as if he were an unit of the average ; whereas, in fact, each man is markedly different from every other, and the average eliminates the differences. On the other hand, the Law, or abstract formula of the concretes, is valid when once verified ; any contra- diction to such a law must be assigned either to a mis- interpretation of its terms, or to a misapplication of it to the case in point. An example of misinterpreta- tion is the common opposition to Mr Buckle's state- ment that the number of marriages in a community THE RULES OF PHILOSOPHISING. 105 is regulated by the price of corn, and not at all by the inclinations of the sexes. He has expressed this law so unguardedly that readers in general have rejected it with indignation. But if we reflect that the inclina- tions of the sexes are constant factors which would determine the marriage of all men and women, were their inclinations left unopposed, and if we recognise among the grounds of opposition none at once so general and so imperative as the need of sufficient food, we see that food must be the variable factor determining the variation in the number of the un- married, which variation it is that the statistical law formulates. Mr Buckle was injudicious and wrong in saying that the inclinations have nothing to do with marriage; what they have nothing to do with is the variable number of the unmarried, a number expressive of the perturbations to which sexual unions are subjected. EULE XIV. " In experimental philosophy we are to look upon propositions collected by general induc- tion from phenomena as accurately or very nearly true, notwithstanding any contrary hypotheses that may be imagined, till such time as other pheno- mena occur by which they may be made more accurate or liable to exceptions. 1 ' REMARK. This is Newton's Fourth Kule, and he remarks that we must follow it in order that the argument of induc- tion may not be invaded by hypothesis ; in other words, without too confidently relying on the universality of 106 PROBLEMS OF LIFE AND MIND. an induction, we must always prefer it to any reasoning not founded on an inductive basis. RULE XV. "Always to prefer the simplest hypothesis compatible with all the observed facts." REMARK. This is Comte's first law of Primary Philosophy ; and however self-evident it may appear, is very frequently disregarded, because the scientific use of Hypothesis is so little understood. That many more rules might be added is indisputable; but these fifteen are all that I deem necessary for my present purpose. They will be implied throughout the following investigations, and from time to time specially invoked. PSYCHOLOGICAL PRINCIPLES. ALSO bestimmt die Gestalt die Lebensweise des Thieres ; Und die Weise zu leben sie wirkt auf alle Gestalten Machtig zuriick. So zeiget sich fest die geordnete Bildung Welche zum Wechsel sich neigt durch ausserlich wirkende Wesen. GOETHE : Die Metamorphose der Thiere. Entre PHomme et le Monde il faut I'Humanite. AUGUSTS COMTE. NOTE. ALTHOUGH the arguments set forth in the following pages ought to carry with them their own evidence, it may not be without advantage to them if I here set down the Principles adopted from previous writers or arrived at in my own researches, and give a general sketch of what it is pro- posed to establish in several of the Problems to be sxiccessively treated. A systematic treatise on Psychology seems to me premature until there is something like general agreement on many questions of fundamental importance, these being partly metaphysical, and partly biological. In- stead, therefore, of a treatise, I have here sketched the programme of Psychology ; and in the ensuing pages have undertaken the examination at some length of those questions which seemed most pressing. What is here set down must be accepted as a programme only. I do not pause to prove the positions ; in many cases I do not even illustrate them. The reader is not called upon to assent to them ; he is only asked to consider that they are the positions on which I have founded my arguments. They may, perhaps, also be accepted as suggestions to fur- ther inquiry. PSYCHOLOGICAL PRINCIPLES. 1. MAN is not simply an Animal Organism, he is also an unit in a Social Organism. He leads an individual life, which is also part of a collective life. Hence two classes of Motors : the personal, and the sympathetic the egoistic and the altruistic. From these chiefly issue the Animal sentient life, and the Human intel- lectual and moral life. Human Psychology, therefore, the science of psychi- cal phenomena, has to seek its data in Biology, and in Sociology. The great mistake hitherto has been either that of metaphysicians, seeking the data solely in intro- spective analysis of Consciousness ; or that of biologists, seeking the data in the combination of such analysis with interpretation of nervous phenomena. 2. The biologist who is true to scientific Method accepts Vitality as an ultimate fact, of which he only seeks the factors, *. e., its conditions, and its laws of manifestation. He leaves to metaphysicians the ulterior task of settling, if they can, what Life is, apart from these, or in the general system of things. The mathematician does not concern himself with what Quantity, Space and Time are ; nor the physicist with what Force is ; nor the biologist with what Life is. 110 PROBLEMS OF LIFE AND MIND. The psychologist likewise must accept Consciousness, or to speak more precisely, Sensibility, as an ultimate fact, of which he only studies the factors its con- ditions and laws. The analogy of Life and Mind is the closest of all analogies, if indeed the latter is anything more than a special form of the other. Hence what is known of Life will be the best guide to what is knowable of Mind. Both are processes, or, under another aspect, functional products. Neither is a substance ; neither is a force. To speak of Vitality as a substance, would shock all our ideas ; but many speak of it as a force. They might with equal propriety hold Mortality to be a force. What, then, is meant by Vitality, or vital forces \ If the abstraction be resolved into its con- cretes, it will be seen that a certain process, or group of processes, is condensed into a simple expression, and the final result of this process is transposed from a re- sultant into an initial condition, the name given to the whole group of phenomena becomes the personification of the phenomena, and the product is supposed to have been the producer. In lieu of regarding vital actions as the dynamical results of their statical conditions, the actions are personified, and the personification comes to be regarded as indicating something independent of and antecedent to the concrete facts it expresses. The vital force manifested by an Organism may be likened to the mechanical force manifested by a Machine. No one really tries to reach and modify the mechanical force (which is a pure abstraction), he only tries to reach and modify the mechanical conditions (which are reals), certain that if he lessen the friction of the parts he will increase the mechanical product. In PSYCHOLOGICAL PRINCIPLES. Ill like manner, no philosophic biologist now tries to reach and modify a vital force, but only to reach and modify those biostatical conditions which, when con- sidering them as causes, and condensing them all into a single expression, he calls Vitality or the Vital Forces. When we speak of electrical force, cohesive force, attractive force, and the like, we are using ab- stractions which condense a vast amount of concrete observation; but it is not on these abstractions that our experiments lay hold, it is on the concrete pheno- mena themselves. The same is true of Sensibility. Vitality and Sensi- bility, Life and Consciousness, are abstractions having real concretes. They are compendious expressions oi functional processes conceived in their totality, and not at any single stage. A function is the activity of an organ. And since Function is a conception which is in its very nature distinguished from the material con- ditions, obviously both Life and Mind are terms which designate phenomena that are immaterial, the two con- ceptions of Matter and Motion, although correlative, being mutually exclusive. In so regarding them, how- ever, we are not to conclude that this exclusion justifies the spiritual hypothesis of Life and Mind. This hypo- thesis is simply a reintroduction of an unknown kind of Matter to serve as the Substance, in lieu of the known Matter which is presented by the Organism. Who does not see the contradiction of requiring a substance for that which by its definition is not substantial at all, but pure dynamism ? 3. We cannot be sufficiently on our guard in the use of abstractions, and especially against our tendency to confound ideal separations with real separations. It is 112 PROBLEMS OF LIFE AND MIND. this tendency which keeps up the tradition of Mind existing apart from Life, and following other laws. We separate, for convenience, mental phenomena from other vital phenomena, and then again separate mental phenomena from neural phenomena; this done, we overlook the real identity, and do not see that every mental phenomenon has its corresponding neural phe- nomenon (the two being as the convex and concave sur- faces of the same sphere, distinguishable yet identical), and that every neural phenomenon involves the whole Organism ; by which alone the influence of the body on the mind, and of the mind on the body, can be explained. Among the broad distinctions of phenomena those of Physical, Chemical, and Vital must be maintained, expressing as they do the characteristic motions of propulsion, motions of combination, and motions of evolution. A chemical combination, even if finally reducible to physical laws, is markedly distinguished by presenting new structural relations. A still broader demarcation is given in the vital phenomenon of Evolu- tion (characterised by Nutrition, Development, and Decay, through serial changes), distinguishable from the chemical combinations out of which it emerges. Not only is it impossible to deduce the phenomenon of Evolution from the phenomena of chemical com- bination, not only is it impossible to explain Nutri- tion by Chemistry, unless we replace the Laboratory by the Organism, and thus introduce the special evolutive conditions, namely, the presence of organic substance formed into histological elements, (cells, fibres, tubes); but it is d priori evident that a phe- nomenon differing so widely from all chemical phe- PSYCHOLOGICAL PRINCIPLES. 113 nomena must be due to widely different conditions. We may never know all these conditions; but that analysis will ever resolve them into simple chemical conditions irrespective of the speciality of their theatre, may confidently be denied. It is an old remark that Life escapes under the scalpel, leaving only a dead * subject ' for dissection. Life equally vanishes under chemical analysis. A similar mistake perverts the efforts of most psycho- logists. They do not keep in view the speciality of the psychological theatre, nor allow for the continual pre- sence of those sentient conditions implied in the general term Soul. The spiritualists are prone to split up the sentient organism into independent Faculties, dividing it into Sense, Understanding, Eeason, Volition, &c. The materialists split it up into independent Organs. Thus both schools the school which affirms the unity of the Soul in its spiritual substance, and the school which affirms the dependence of the Soul on its cerebral sub- stance practically deny their principle when they come to treat mental phenomena in detail. And in both cases the source of the error is the ex- clusive employment of Analysis without the due regard to its needful correction by Synthesis. Theoretically taking the Organism to pieces to understand its separate parts, we fall into the error of supposing that the Or- ganism is a mere assemblage of organs, like a machine which is put together by juxtaposition of different parts. But this is radically to misunderstand its essential nature and the universal solidarity of its parts. The Organism is not made, not put together, but evolved; its parts are not juxtaposed, but differentiated; its organs are groups of minor organisms, all sharing in a VOL. T. H 114 PROBLEMS OF LIFE AND MIND. common life, i.e., all sharing in a common substance constructed through a common process of simultaneous and continuous molecular composition and decomposi- tion ; precisely as the great Social Organism is a group of societies, each of which is a group of families, all sharing in a common life every family having at once its individual independence and its social dependence through connection with every other. In a machine the parts are all different, and have mechanical signifi- cance only in relation to the whole. In an Organism the parts are all identical in fundamental characters, and diverse only in their superadded differentiations : each has its independence, although all co-operate. The syn- thetical point of view, which should never drop out of sight, however the necessities of investigation may throw us upon analysis, is well expressed by Aristotle some- where to the effect that all collective life depends on the separation of offices and the concurrence of efforts. In a vital organism every force is the resultant of all the forces ; it is a disturbance of equilibrium, and equi- librium is the equivalence of convergent forces. When we speak of Intelligence as a force which determines actions, we ought always to bear in mind that the effica- city of Intelligence depends on the organs which co- operate and are determined : it is not pure Thought which moves a muscle, neither is it the abstraction Contractility but the muscle which moves a limb. To those who, having relinquished the spiritualist hypothesis, have adopted the view that Mind is only one of the forms of Life, and that Life is not an entity but an abstraction expressing the generalities of organic phenomena, it is obvious that Psychology must en- deavour to ascertain the conditions of these phenomena, PSYCHOLOGICAL PRINCIPLES. 115 both general and special. These may be classed (by a serviceable extension of the term statics) under the heads of Biostatics and Psychostatics. BIOSTATICS. 4. Owing to the necessary abstraction which charac- terises all analytical investigation, we are too prone to neglect that restitution of the omitted elements which is needful when we would complete the analysis by a real explanation. It is thus that we separate each organ or function from its complications with all the others, and forget that it is really only a part of a living whole, and explicable only through the whole Organism. It is thus that we consider only one factor in studying a product, and forget that every product necessarily has at least two factors each equally indis- pensable. When, therefore, we define an Organism it should always be with clear vision of its relation to a Medium ; and when we define a function as the activity of an organ, we should always distinctly recognise the fact that this activity does not take place in vacuo, but involves the co-operation both of that which is acted on and of that which acts. The function of an organ is as rigorously determined by the stimulus which excites it as by the structure which is excited ; unless this unification of the two factors takes place there is no product at all the organ is not active because not adequately stimulated. I shall repeatedly have occasion to invoke this principle, and here simply invoke it in reference to the nutrition of the Organism, the structure of which is built up from materials originally drawn from the ex- ternal Medium, but proximately drawn from its internal 116 PROBLEMS OF LIFE AND MIND. Medium, or plasma. Between the reception of this external material and the assimilation of it by the tissues (of plant or animal), there is always an intermediate stage passed through, the inorganic, unvitalised material becoming there transformed into organisable, vitalised material. What this special change is we do not know; we only know that until it has taken place the in- organic material is not assimilable; it must enter as a constituent of the Bioplasm to form part o.f what Claude Bernard calls the Physiological Medium, before it can become a constituent of the tissues. The suppo- sition that plants are nourished directly by inorganic substances drawn from the soil and atmosphere, is now proved to be erroneous ; the Nutrition of plants takes place through processes similar to those in animals. The inorganic has in both to pass through the organis- able stage, and form proximate principles, before it can become organised into elements of tissue. 5. Among the most important laws of Biostatics may be named the following : I. The Law of Correlated Development. There is a marked tendency in organic substance to vary under varying excitations, which results in the individualis- ation of the parts, so that growth is accompanied by a greater or less differentiation of structure. Were this tendency uncontrolled, there would be no organic unity : the organism would then be simply an assemblage of organs. But owing to the solidarity which under- lies all differentiation, the parts are not only indi- vidualised into tissues and organs, but are all con- nected. Thus each new modification of structure is se- cured, each organ is independent yet subordinated to the whole ; and instead of being an obstacle, this indepen- PSYCHOLOGICAL PRINCIPLES. , 117 dence becomes, through the consensus and co-operation of each, a source of enhanced power in the organism. In organic, as in social life, the indispensable condition of perfect action is the co-operation of independent agents the Freedom which is subordinated to Law, and the Law which secures Freedom. II. The Law of Adaptation. Although an organ can only respond to a stimulus according to its own modes, which depend on its structure, and which vary with the variations of structure, yet the very reaction itself tends to establish a modification which will alter sub- sequent reactions. It is in this sense, and this alone, that we must understand the statement that organs are created by functions. What is exact in the state- ment is that by the exercise of an organ its structure becomes differentiated, and each modification renders it fitted for more energetic reaction and for new modes of reaction.""" But we must never lose sight of the abso- lute principle that Function is the action of Organ, and can never be dynamically other than what its statical conditions permit. III. The Law of Heredity. The modifications of structure acquired through Adaptation tend to be- come transmitted to offspring, and would always in * How important this principle is in the evolution of our moral no less than our intellectual aptitudes may be seen in the growth of the sympathetic tendencies. " Telle est la douceur naturelle des bons senti- ments que, de quelques excitations que provienne leur eveil, ils tendent a se developper par leur propre charme, quand ils ont une fois surgi, meme d'apres un motif personnel, trop souvent indispensable a leur tor- peur primitive." COMTE, Politique Positive, ii. 119. Unhappily our bad sentiments follow the same law, and become intensified by exercise. Herein lies the supreme importance of an Education which is directed towards the development of aptitudes by their effective exercise, rather than by the inculcation of rules. 118, PROBLEMS OF LIFE AND MIND. effect be transmitted were it not for perturbations of the result owing to the action of external forces dur- ing the embryonic development, and to the influence of the other parent. PSYCHOSTATICS. 6. Let us now pass from Life to Mind. The vital organism we have seen to be evolved from the Bioplasm, and we may now see how the psychical organism is evolved from what may be analogically called the Psychoplasm. The Bioplasm is character- ised by a continuous and simultaneous movement of molecular composition and decomposition ; and out of these arises the whole mechanism, which is also sustained and differentiated by them. If, instead of considering the whole vital organism, we consider solely its sensitive aspects, and confine ourselves to the Nervous System, we may represent the molecular movements of the Bioplasm by the neural tremors of the Psychoplasm : these tremors are what I term neural units : the raw material of Consciousness ; the several neural groups formed by these units represent the organised elements of tissues, the tissues, and the com- bination of tissues into organs, and of organs into apparatus. The movements of the Bioplasm consti- tute Vitality ; the movements of the Psychoplasm con- stitute Sensibility. The forces of the cosmical medium which are transformed in the physiological medium build up the organic structure, which in the various stages of its evolution reacts according to its statical conditions, themselves the results of preceding reactions. It is the same with what may be called the mental organism. Here also every phenomenon is the pro- PSYCHOLOGICAL PRINCIPLES. 119 duct of two factors external and internal, impersonal and personal, objective and subjective. Viewing the internal factor solely in the light of Feeling, we may say that the sentient material out of which all the forms of Consciousness are evolved is the Psychoplasm incessantly fluctuating, incessantly renewed. Viewing this on the physiological side, it is the succession of neural tremors, variously combining into neural groups. 7. An organism lives only in relation to its medium. What Growth is, in the physical sense, that is Experi- ence in the psychical sense, namely, organic registra- tion of assimilated material. The direct relation of the organism is to the internal medium, the indirect relation is to the cosmical medium. The Bioplasm is constituted out of the fluids which bathe the tissues, and from which each tissue derives its nourishment, molecule by molecule. It is necessarily liquid because in a tissue liquidity is requisite for chemical action. Hence Claude Bernard suggestively notes that the cellular elements of the tissues are veritable aquatic organisms. The internal medium is incessantly fluc- tuating : a point to which especial attention must be given. Materials are incessantly absorbed from with- out, and are there elaborated, made fit for assimilation. Materials are also incessantly thrown into it as products of waste of tissue, and have to be excreted. Thus does the Bioplasm contain the materials of Yesterday, the materials of To-day, and the materials of To-morrow. Nutrition may, to speak mathematically, be designated a function of three variables, namely tissue, internal medium, and cosmic medium. A little more heat or a little less of carbonic acid, or of oxygen, pressure, &c., in the external, will accelerate or retard the evolutions of 120 PROBLEMS OF LIFE AND MIND. Nutrition by its effects on the internal medium. But no variation in the cosmic medium which does not affect the internal medium will have any modifying influence on the organism. This also it is important to bear in mind. The direct relation is between the organism and the internal medium : these two factors therefore comprise the Biostatical conditions ; and the influence of the external medium is through these. Food is not food, nor is poison poison, until it has passed into the Bioplasm. 8. The reader sees at once how this applies to the sentient organism. We have already spoken, meta- phorically, of the Psychoplasm, or sentient material forming the psychological medium from which the Soul derives its structure and its powers. It is the mass of potential Feeling derived from all the sensitive affections of the organism, not only of the individual but, through Heredity, of the ancestral organisms. All sensations, perceptions, emotions, volitions, are partly connate, partly acquired : partly the evolved products of the accumulated experiences of ancestors, and partly of the accumulated experiences of the individual, when each of these have left residua in the modifications of the structure. Thus Vitality and Sensibility may be said to rest on seriated Change. If the changes were simply move- ments, propulsive or combined, physical or chemical, they would not present the phenomena of Life or of Consciousness. The changes must be serial, and what we term organised, to present the phenomena of Evo- lution. That Life is Change, and that Consciousness is Change, has always been affirmed. We have only to add that the changes are serial, and convergent PSYCHOLOGICAL PRINCIPLES. 121 through a consensus determined by essential com- munity of structure, and we have characterised the speciality of organic change, demarcated Life and Mind from all inorganic change. 9. Corresponding with the Biostatical laws previ- ously formulated there are three Psychostatical laws. I. The Law of Interest. It has long been observed that we only see what interests us, only know what is sufficiently like former experiences to become, so to speak, incorporated with them assimilated by them. The satisfaction of desire is that which both impels and quiets mental movement. Were it not for this con- trolling effect of the established pathways, every exci- tation would be indefinitely irradiated throughout the whole organism ; but a pathway once established is the ready issue for any new excitation. The evolution of Mind is the establishment of definite paths : this is the mental organisation, fitting it for the reception of definite impressions, and their co-ordination with past feelings. II. The Law of Signature. Every feeling being a group of neural units, and varying with the varying units, or varying groups of such groups, has its par- ticular signature, or mark in Consciousness, in con- sequence of which it acquires its objective Localisa- tion, i.e., its place in the organism or in the cosmos. III. The Law of Experience. This is only the mental side of the laws of Heredity and Adaptation. Experience is the registration of Feeling. Through their registered modifications, feelings once produced are capable of reproduction; and must always be re- produced, more or less completely, whenever the new excitation is discharged along the old channels. 122 PROBLEMS OF LIFE AND MINT). The laws just formulated are special forms of the primary law, which in Biology is expressed in the formula : Every vital phenomenon is the product of two factors, the Organism and its Medium; and in Psychology is expressed in the equivalent formula : Every psychical phenomenon is the product of two factors, the Subject and the Object. The importance of keeping these steadily before us in all detailed inves- tigation, and the frequent mistakes which arise from overlooking them, will appear in the course of this work. Note, in passing, that the latter formula replaces the old Dualism, in which Subject and Object were two inde- pendent and unallied existences, by a Monism, in which only one existence, under different forms, is conceived. The old conception was of Life in conflict with the External; the new conception recognises their identity; and founds this recognition on the demonstrable fact that so far from the external forces tending to destroy Life (according to Bichat's view) they are the very materials out of which Life emerges, and by which it is sustained and developed. 10. There are of course several other derivative laws, but these three are the principal, and are all that need be noted here. A glance at them suffices to discredit the old idea that the Senses directly apprehend or mirror external things. It is equally mistaken to suppose that sensitive impressions are the immediate motors. Each excitation has to be assimilated taken up into the psychological medium and transformed into a sensation or perception : a process that will depend upon the psychostatical conditions at the time being. The different ways in which the same ex- ternal stimulus affects different organisms, or the same PSYCHOLOGICAL PRINCIPLES. 123 organism at different times, are thus explicable. Think of the diversities of feeling produced by the image of a sheep on the retina of a man and a wolf, or of an artist and a grazier. Think of the dissimilar effects pro- duced by the same musical intervals on the organism of an Asiatic and on that of an European. Or, take an example from Insanity: A visceral disturbance, especially in the digestive or the generative organs, will cause a perversion of Sensibility from which will arise abnormal sensation, hallucination, moods, melancholy, depression, &c. These prompt the intellect to explan- ation. External causes are imagined; and the wildest hypotheses of persecution, divine or diabolic commu- nication, are invented. As the disturbance spreads and the organism becomes more and more abnormal, the ideas become more and more incoherent, till De- mentia supervenes. This influence of the psychostatical conditions in determining the character of every psychical pheno- menon suggests an important distinction which must be established between Animal Consciousness and Human Consciousness, one far greater than any other distinction to be established between Animals and Man. It is formulated by Auguste Comte in that phrase which is placed as an epigraph to this chapter, although the phrase was not by him understood precisely in the sense here assigned. AVe have seen how between the Cosmos and the Consciousness there is interposed a psychological medium, briefly designated by the term Experience. This applies both to animals and to man. But in man we must recognise another medium, one from which his moral and intellectual life is mainly drawn, one which separates him from all animals by the 124 PROBLEMS OF LIFE AND MIND. broadest line : this is the Social Medium the collective accumulations of centuries, condensed in knowledge, beliefs, prejudices, institutions, and tendencies; and forming another kind of Psychoplasm to which the animal is a stranger. The animal feels the Cosmos, and adapts himself to it. Man feels the Cosmos, but he also thinks it ; again he feels the Social world, and thinks it. His feelings and his thoughts of both are powerfully modified by residua. Hence the very Cosmos is to him greatly different from what it is to the animal ; for just as what is organised in the individual becomes trans- mitted to offspring, and determines the mode in which the offspring will react on stimulus, so what is registered in the Social Organism determines the mode in which succeeding generations will feel and think. By Tools and Instruments, by Creeds and Institutions, by Liter- ature, Art, and Science, the Social Organism acquires and develops its powers; and how even simple per- ceptions are modified by social influences will strikingly appear in a subsequent part of this work, wherein it will be shown that all perceptions are the results of slow evolution, as the organic forms are; and not only will it be shown that many thousands of years passed before even man was able to perceive the colour blue, for instance, (though of course he felt a difference between a blue object and a brown one) it will be shown that no animal can possibly perceive blue as we perceive it ; and the reason in both cases is not to be sought in physiological processes of Vision, but in psycholo- gical processes of Thought. The possibility of this per- ception is due to Language ; and Language exists only as a social function. PSYCHOLOGICAL PRINCIPLES. 125 THE METHOD OF PSYCHOLOGY. 11. Here we may briefly indicate the Method to be pursued. The mental life of man has two sources : 1, the animal organism, and 2, the social organism. Man apart from Society is simply an animal organism; restore him to his real position as a social unit, and the problem changes. It is in the development of Civilisation that "we trace the real development of Humanity. The soul of man has thus a double root, a double history. It passes quite out of the range of animal life; and no explanation of mental phenomena can be valid which does not allow for this extension of range. Nevertheless I believe this necessity of extending the survey is now for the first time placed on its true footing; nor was it, indeed, even recognised, until Comte, in his second great work, instituted his theorie de Tdme by the com- bination of the biological and the sociological points of view.** * In the present brief indication of my scheme I cannot pause to assign to each philosopher the conceptions adopted from him, nor will the well- read student need such references ; but, as COMTE'S Politique Positive will be known to few of my readers, justice demands a summary state- ment of the fundamental agreement and difference between his conception and my own. They agree in regarding Science as a social product stimu- lated by social needs, and constructed by the co-operation of successive generations, so that civilisation and Humanity are developed pari passu. They agree in subordinating individual introspection to the study of the collective evolution. " Quand j'eus fondd la sociologie," says Comte, " je compris enfin que le genie de Gall n'avait pu construire une veritable phy siologie du cerveau faute de connaitre les lois de 1'evolution collective qui seule en doit fournir a la fois le principe et le but." ( I. 729. Compare III. 45-6.) But they differ primarily in this : he holds that Humanity de- velops no attribute, intellectual or moral, which is not also to be found in A.nimality (I.) 624, whereas I hold that the attributes of Intellect and Conscience are special products of the Social Organism, and that although animals possess in common with man the Logic of Feeling, they are wholly deficient in the Logic of Signs, which is a social not an animal function. 126 PROBLEMS OF LIFE AND MIND. 12. For a very long period philosophers deemed it enough to study Mind with little reference to its depen- dence on the Organism : the introspection of Conscious- ness was supposed to be sufficient. Nay, even when Physiology began to furnish indications of the connec- tion between vital and psychical phenomena, and to exhibit the dependence of mental states on neural states, the psychologists pointed to the fact that Consciousness told us nothing of such dependence; and hence they concluded that Psychology, occupied solely with Consciousness and its changes, need not concern itself with Physiology and its laws. Kightly inter- preted, this very fact that Consciousness tells us nothing of its physiological conditions, would have been recognised as fatal to the pretensions of the introspective Method. Indeed Psychology without illumination from Biology is something like the Astronomy of the Chaldeans without the aid of Mathematics; watching the stars however patiently would no more disclose the laws of their movement, than watching the changes in Consciousness would dis- close their laws. Not only were centuries of such ob- servation inadequate, but we now know that some of the elementary facts escaped notice, and must for ever have escaped it unless otherwise aided. This need not be insisted on, however, since there is now an almost universal agreement respecting the necessity of studying the organism ; and many psycho- logical treatises are avowedly based on the Physiology of the Nervous System, while all largely invoke physi- ological aid. We may observe, indeed, in most of these a disposition to translate psychological observa- tions into physiological language, and to accept this as PSYCHOLOGICAL PRINCIPLES. 127 biological illumination ; which not unjustifiably excites the scorn of the pure psychologist. One example of this translation may be given here : some anatomists having conceived the infelicitous idea of distinguish- ing nerve-cells into sensory, motor, and sympathetic, this nomenclature, so misleading even when it is not pro- foundly unphysiological, is adopted by several writers, who first establish the illusory distinctions of sensa- tional cells, ideational cells, and emotional cells, and then proceed to explain the mental mechanism by these imaginary cells. The early chemists paid no attention to the part played by the air in Combustion; nay, it was long before the fact of its materiality was vividly realised, and a century after Torricelli it was first recognised as an agent in Combustion. No wonder, therefore, if for a long while Biology paid insufficient attention to the Medium as a necessary co-operant, and directed its study mainly to the Organism. This mistake has been rectified, and now the true relation is always recognised. There must be a parallel rectification in Psychology : the co-operation of Object and Subject must never for a moment be lost sight of. Yet even this will only furnish one-half of the neces- sary data. Let us suppose the student equipped with all the aid which the science of the clay will supply, not only respecting the normal actions of the nervous system, but also respecting its abnormal actions, especially in Insanity, he will still need to invoke another aid, for he will only have what may be called biological data, and will still need the equally important sociological data. Having studied the Organism in relation to its Medium, he has only studied the Animal side of the 128 PROBLEMS OF LIFE AND MIND. problem ; there still remains the Human side, and he has to study the Organism in relation to the Social Medium, in which man lives no less than in the Cosmical Medium. If there is a valid objection against the functions of the brain being investigated in the cabinets of metaphysicians, there is an equally valid objection against intellectual and moral processes being sought in the laboratories of physiologists. To under- stand the Human Mind we must study it under its normal conditions, and these are social conditions. And it may be observed that the psychologist, mor- alist, and politician often disregard a fundamental truth which is never disregarded by the physicist : the truth that it is vain to expect a result in the ab- sence of its necessary conditions. The politician who will cordially admit the axiom that * Constitutions are not made but grow,' will nevertheless daily be found endeavouring to remedy social evils by legislative enactments, which leave the conditions unchanged. The moralist will be found passionately arguing that the conduct of men, which is simply the expression of their impulses and habits, can be at once altered by giving them new ideas of right conduct. The psychologist, accustomed to consider the Mind as something apart from the Organism, individual and collective, is peculiarly liable to this error of overlook- ing the fact that all mental manifestations are simply the resultants of the conditions external and internal. THE BIOLOGICAL DATA. 13. In its relations to the Cosmos, and under what may be called the purely biological aspect, the Organ- ism presents two points of study : the biostatical and PSYCHOLOGICAL PRINCIPLES. 129 the biodynamical i. e., the consideration of the struc- ture ready to act ; and the consideration of the struc- ture acting. 14. The statical aspect of the Organism is that of the balance of its nutritive forces developed in the molecular movements of composition and decomposi- tion. The balance itself is incessantly fluctuating ; for the Organism, although a mechanism, is specially dis- tinguished from every other kind of mechanism by the instability of its materials. A watch wound up to- day is the same as it was yesterday, and will be to- morrow. No Organism is so, for it is living, growing, changing. The structure and actions of the watch are unaffected by the surrounding changes, unless these changes have a direct relation to it. It is unaffected by a snow-storm, a dog in the room, a political crisis ; all of which affect the Organism, or may affect it. Moreover, the Organism is affected by its own internal changes, by the food it has eaten, the feelings it has felt, the dreams that have varied its sleep, &c. 15. The force stored up in the tissues through nutritive changes is liberated by stimuli internal and external. This is the biodynamical aspect, including the physiological properties of the tissues. From various combinations of the tissues result organs; from various combinations of the properties result functions. (It is of supreme importance to bear in mind the distinction between the property of a tissue, and the function of an organ, or group of organs.) 16. The Organism exhibits three fundamental modes : Assimilation, Sensibility, and Motility. From the first of these issue the general laws of Nutrition whence Growth, Development, and Keproduction. VOL. I. I 130 PROBLEMS OP LIFE AND MIND. From the second issue the general laws of Feeling, using that term in its widest sense, including Sensa- tion, Perception, Emotion, Volition, and Intelligence, and also Instinct (which is Impulse and organised Intelligence).* From the third issue the general laws of Action, including Impulse, Automatic Movement, Keflex Movement, and Voluntary Movement. 17. This separation must be understood as purely analytical. In reality the three modes are inseparable. Assimilation may perhaps take place without the intervention of Sensibility at least in Plant organ- isms but it is certain that the processes of Growth, Development, and Reproduction are in the Animal very much determined by the reactions of Sensibility ; while it is obvious that they require Movement, mo- lecular and inolar. Sensibility, in turn, requires the incessant co-opera- tion of Assimilation, from which is drawn the material of the sensitive structure and the force expended in its function. Motility, again, requires both the stimulus and the guidance of Sensibility. The animal must feed to live ; it must move its organs to get and eat the food ; it must feel the stimulus of hunger to impel its movements, and the satisfaction of desire to deter- mine its selection of food ; in this Discrimination lies the germ of Intelligence. 18. All sensitive affections have the quality of Pleas- * Dr Johnson, on being asked whether there was not Imagination in a certain poem, answered, "No, sir, there is what was Imagination once." In like manner we may say that in Instinct there is not In- telligence, but what was once Intelligence: the specially intelligent character has disappeared in the fixed tendency. The action which formerly was tentative, discriminative, has now become automatic and irresistible. But the impulse is always guided by feeling. See further on, 30. PSYCHOLOGICAL PRINCIPLES. 131 ure, or its correlative Pain. These qualities tend to fade into relative indistinctness with the decrease in energy consequent on ease of neural discharge, conse- quent on frequency of repetition at brief intervals. 19. All sensitive reactions have their Signatures. In proportion as their intensity and massiveness decrease they become more and more Signs, and thus become fitted to enter into intellectual operations which are purely symbolical. The least sensible of the Senses, if the expression may be allowed, is Sight, and therefore it is the most intellectual. It is the most impersonal that which draws with it the least amount of feeling. In looking at an object, it is the object out of us which most calls upon the attention. Only when we touch, taste, or smell the moving object, does it seem to enter into personal feeling. On the other hand a more subjective feeling, say of sound or taste, becomes objective so soon as it is connected with a sight or a touch. 20. Sensations are usually, but improperly, restricted to the reactions of what are called the Five Senses, and which are commonly spoken of as the Senses. This is doubly wrong. A sensation is not a simple excitation of the sensory organ, but a compound of that with the consequent excitation of a Perceptive Centre. The excitation of the sense organ is only one element in a complex process. Divide the optic nerve before its entrance into the optic ganglion, and no excitation of the retina will produce a luminous sensation ; cut off an animal's leg, and stimulate the sciatic nerve, the leg will move, but no sensation will have been produced. Nor is this all. Unless the excitation is assimilated by the psychological medium 132 PROBLEMS OF LIFE AXD MIND. it does not become sentient; and unless it becomes sentient it cannot become a sensation. Quitting the analytical point of view we at once recognise the fact that every perception instead of being the reaction of a single organ is the resultant of the combined reactions of the whole Organism ; the only question in each case being the relative propor- tions of the parts involved, and how far the irradiation has been restricted to certain channels. The several Senses are no more vicarious than the several Secre- tions ; and when we see an apple we do not in the visual sensation include the sensations of taste, frag- rance, resistance, &c., which are all included in the per- ception of an apple, because all more or less excited by the irradiation of the optical stimulus. It is the non- recognition of this which originates many of the diffi- culties touching the theory of Vision. The organic seat of Vision is too often assumed to be the retina ; whereas that is only the seat of the visual excitation, which in the Perceptive Centre is blended with the residua of other excitations. 21. The same is true of all sensations, the Systemic no less than those of the special Senses. And this leads me to the second error just referred to, the re- striction of Sensation to the reactions of the Five Senses. Physiology teaches us that there is another and indeed far more important class of sensations, arising from what I have proposed to call the Systemic Senses, because distributed through the system at large, instead of being localised in eye, ear, tongue, &c. Although not so easily and definitely assigned to spe- cial organs, they may be classified as the Nutritive, Re- spiratory, Generative, and Muscular Senses. The feel- PSYCHOLOGICAL PRINCIPLES. 133 ings accompanying secretion, excretion, hunger, thirst, &c., belong to the first. The feelings of suffocation, oppression, lightness, &c., belong to the second. The sexual and maternal feelings belong to the third; while those of the fourth enter as elements into all the others. The Systemic Sensations not only blend with those of the Five Senses to produce Desires, Emotions, In- stincts, &c., they make up the greater part of that continuous stream of Sentience, on which each ex- ternal stimulus raises a ripple. 22. One aim of Psychology is to reduce sentient facts to physiological facts. Consciousness precedes Science. We learn slowly to assign certain feelings to the Five Senses because the stimuli of these Senses are objectively appreciable we can see the object we have touched, and taste the object we have seen. Not so with the Systemic feelings. Their stimuli, because internal, cannot be alternately submitted to various Senses. Still further removed from such objective appreciation are the central processes of Judgment, Memory, Imagination, &c. ; and hence the disposition to regard these feelings as due to another source ; it is even paradoxical to speak of such processes belonging to Feeling, and to affirm that the Laws of Thought are identical with the Laws of Sensation, differing not as operations, but only in the materials operated on. The paradox disappears when we learn to consider psychical phenomena in the true synthetic way ( 3). 23. The sensations of the Five Senses are more im- personal than those of the Systemic Senses ; hence their greater importance in the construction of objec- tive knowledge. They are pre-eminently intellectual, not only on this ground, but also because of their PROBLEMS OF LIFE AXD MDO). inferior massiveness and diffusiveness, and of their greater capability of definite localisation : hence they are fitted to become signs. The systemic sensations have, however, great importance, and their immense superiority as motors has been singularly overlooked. They make up by far the larger portion of our sentient material, since from them mainly issue the Emotions, Sentiments, &C-, combined indeed with the objective sensations, but subordinating these as means to their ends, inasmuch as we only see what interests us. Note here, in passing, the error which arises from not viewing the organism synthetically, but detach- ing the Intellect, and treating it independently. Having separated it from the Feelings, philosophers have been led to pay exclusive attention to the Five Senses, overlooking the necessary subordination of these to the more fundamental and energetic Systemic Senses. Hamann picturesquely expresses the general error when he says : " The Five Senses are the five loaves with which Jesus fed the multitude." I hope to show in detail that it is not these which supply our highest spiritual food ; and that the doctrine of the Sensational School is wholly untenable, partly because our highest knowledge is not gained through the Senses in any such way, but is gained through psychological evolution of sociological material; and partly also because if we isolate the Animal from the Social Organism, the Senses furnish only a small quota to the mass of human Experience. PSYCHODYXAMICS. 24. From the biological stand-point our first division of the Organism is into Affective and Active, which PSYCHOLOGICAL PRINCIPLES. 135 division represents the reception of stimulus, and the discharge of force : sensation, and movement. The physiological fact, first enunciated by me, and now adopted by some teachers of great eminence (Vulpian, Gavarret, &c.) that nervous tissue is identical throughout in Property as in Structure, has extremely important consequences.* For if the Property be everywhere the same, all the Functions, into which that property enters, must have a common identity; differing quantitatively among themselves only so far as neural processes are concerned, they will of course differ qualitatively in so far as other elements enter into the functions : thus the Neurility which stimulates a muscle is identical with the Neurility which stimulates a gland, but the functions of Locomotion and Secretion, involving different organs, are qualitatively different. The great problem of Psychology as a section of Biology is, in pursuance of this conception, to develop all the psychical phenomena from one fundamental process in one vital tissue. The tissue is the nervous : the process is a Grouping of neural units. A neu- ral unit is a tremor. Several units are grouped into a higher unity, or neural process, which is a fusion of tremors, as a sound is a fusion of aerial pulses ; and each process may in turn be grouped with others, and thus, from this grouping of groups, all the varieties emerge. What on the physiological side is simply a neural process, is on the psychological side a sentient process. We may liken Sentience to Combustion, and * The only psychologist whom I can cite as having adopted this physiological principle, and extensively applied it in the investigation of mental phenomena, is ADOLF HORWICZ, whose Psycliologische Ana- lysen auf physiologischer Grundlage (Halle, 1872) maybe recommended to the attentive study of all interested in this subject. 136 PROBLEMS OF LIFE AND MIND. then the neural units will stand for the oscillating molecules. Sentience may manifest itself under the form of Consciousness, or under that of Sub-Conscious- ness which may be compared to Combustion mani- festing itself in Flame and in Heat.' 25. The grouping, or active aspect of the affective, or sentient state, is what may analytically be called the Logical element. Logic we have already seen may comprise all the laws of grouping, subjective and objective (Introd. 65). I institute a marked division into the Logic of Feeling and the Logic of Signs ; ranging under the first all the laws of grouping manifested in Sensation, Perception, Emotion, Instinct, with a further subdivision into the Logic of Images, which is intermediate between that of Feeling and that of Signs ; under the second head, all the laws of Con- ception, or what is specially termed Thought. It is necessary to distinguish Conception, or the formation of symbols expressing general ideas, from Perception, or the formation of particular ideas by synthesis of sensations. Conceptions are no more like real objects than algebraic formulae are like the numbers whose relations they symbolise. Our perception of an animal, or a flower, is the synthesis of all the sensations we have had of the object in relation to our several senses ; and it is always an individual object represented by an individual idea : it is this animal, or this flower. But our conception of an animal, or flower, is always a general idea, not only embracing all that is known or thought of the class in all its relations, but abstracted from all individual characteristics, and is not this ani- mal or this flower, but any one of the class ; just as a and b in Algebra are not quantities and magnitudes PSYCHOLOGICAL PRINCIPLES. 137 but their symbols. Perceptions are concerned directly with the terms of Feeling ; Conceptions with the ratios of those terms. Hence the real nature of the one, and the symbolical nature of the other. 26. Another biological principle teaches that an Or- ganism, being a structure in relation to a Medium, is determined to action by stimuli, both external and in- ternal, and therefore its most general characteristic is that of Reflex action the issue of an excitation in a movement. A stimulus is reflected from one part of a tissue to another, and (owing to the continuity of the tissues) from one organ to another, till it terminates in a movement, which may either be the movement of some special organ, or of some component part of an organ : in every case the motion which originally came from the external Medium is restored to it again, and, so far as the Organism is concerned, it there comes to an end. 27. This REFLEX is a process of Grouping under- lying all psychical phenomena. Its summa genera are FEELING and ACTION. The Organism is stimulated to action by Sensation, and guided by Intelligence the affective becomes ac- tive, not in the sense in which one phenomenon is suc- ceeded by a different phenomenon, but in the sense in which vis tensionis passes into vis viva. The determi- nations of this process are logical, even in the simplest and most rudimentary cases ; for the neural units must be grouped, if a sensation is to result. Intelligence, which in its rudimentary form is simply Discrimination in Feeling, becomes, in its highest forms, the Discrimination of remote meanstowards desired ends. In what is called pure Thought, the means are so remote 138 PROBLEMS OF LIFE AND MIND. from the ends that the ends are scarcely recognisable ; these means then become ends for the Intellect. 28. The popular classification which condenses one large group of phenomena under Feeling, and another under Intellect, the one eminently personal, the other impersonal, would have been more serviceable had it not been hampered by two misconceptions, one respect- ing the assumed independence and autonomy of the Intellect, the other respecting its superior energy and importance. Although it is pretty generally acknow- ledged that ideas have their origin in sensations, it is rarely acknowledged, and is often expressly denied, that all the Feelings, whether those of the Five Senses, specially styled sensations, or those prompted by the Systemic Senses, and more often called impulses, emo- tions, desires, &c., are the real Motors, and that it is they, not ideas, which determine actions. The Intellect, even at its highest, is a guide, not an impulse : it shows the way, it does not cut the way. 29. Whenever the mental phenomena are considered as wholly within the Organism they are Sensation, Emotion, Impulse ; when passing out of the Organism they are Perception, Ideation, Volition. The Feeling which is Sensation or Emotion has little or no reference to any object causing the feeling; whereas Perception, or Ideation, passes beyond the per- sonal circle, projects the Feeling outside as an object. The infant feels a sweet taste, or a soft surface, and feels anger or terror, long before it has assigned sweet- ness and softness to objects as qualities, or learned to form any idea of objects. Such discriminations are the germs of Intelligence, and when Intelligence itself be- comes developed by the large accumulations of such PSYCHOLOGICAL PKINCIPLES. 139 discriminations, it reacts on the feelings, guiding them more and more, and converting blind Impulse into clear Volition. 30. Actions are the energies of organs, and the syn- ergies of groups of organs. They are of two kinds 1, the Fixed, or directly reflex, and, 2, the Facultative, or indirectly reflex, spontaneous. The Fixed Actions are those which uniformly result from excitation of their organs such are the energies of the Senses, and the actions classed under Impulses, Habit, &c. The Facultative Actions are those which, although ulti- mately dependent on the energies of the organs, are yet neither inevitably nor uniformly produced when the organs are stimulated, but, owing to the play of forces at work, take sometimes one issue and sometimes another. No organ has a power of control; but the Organism will control an organ. The individual man is powerless against Society ; but Society can, and does, compel the individual. This does not prevent the in- dividual from initiating a change, which may be passed on from one to another like yeast-cells growing in a fermenting mass ; and in this sense Society is of course affected by the actions of individuals since, indeed, it is itself only the sum of individuals. We may note as one broad characteristic of the social organism, that it is constituted by organs which are independent, and which voluntarily co-operate, the strength of each re- siding in the measure of its co-operation. A man, although powerless against Society, becomes a power with Society. 31. Although all actions are prompted and really guided by Feeling, many of them have so little accom- paniment of what is usually designated Consciousness 140 PROBLEMS OF LIFE AND MIND. that they are said to be insensible. Many of these are called automatic, they are the inevitable activities of the energies or synergies ; many of them are called in- voluntary, and are supposed to be the precursors of the voluntary. These conceptions need modifying. It can be shown that Sentience is involved in all actions, even the auto- matic and involuntary ; and that the actions which are now involuntary were originally voluntary, if by vol- untary we understand the presence of Intelligence. I mean that all such distinctions are psychological, not psychogenetical. They mark differences which now exist, but they do not mark differences in the genesis of the phenomena. The facts of congenital Instincts and of acquired Habits, which operate so rapidly and so se- curely that all the intermediate stages between impres- sion and motion escape notice, has led to the denial of these stages. Thus the uniformity of the earth's move- ment causes us to consider it at rest; we know the movement only through indirect sources. By indirect methods we may also learn that when involuntary or instinctive acts are slackened or thwarted their sen- tient and selective characters appear. Knowing how actions which were once slow and laborious become rapid and easy, and how what cost us painful efforts to learn is now performed without sensible effort, we understand how the voluntary lapses into the invol- untary, and we may be sure that however easy and rapid the process may become, it must necessarily pass through the stages originally followed, though without the irradiation of nascent impulses in other directions. 32. This question of Instinct will occupy us more fully when we come to treat of the origin of knowledge PSYCHOLOGICAL PRINCIPLES. 141 (Prob. I. 21). Enough here to define it as lapsed or un- discursive Intelligence the fixed action of an acquired organisation, transmitted from ancestors who acquired it through Adaptation, whereby what was facultative be- came fixed, what was voluntary became involuntary. The objection will doubtless be raised that Instinct is wholly destitute of the characteristic of Intelligence in that it has no choice : its operation is fixed, fatal. The reply is twofold : in the first place, the objection, so far as it has validity, applies equally to Judgment where, given the premisses, the conclusion is fatal, no alterna- tive being open. Axioms, in this sense, are logical in- stincts. Thus the highest intellectual process is on a level with this process said to be its opposite. And in the second place, the element of choice always does enter into Instinct : although the intelligent dis- crimination of means to ends may be almost absent, it never is entirely. The guiding sensation which directs the impulse is always selective. If we restrict Intelli- gence to the Logic of Signs to ideas there cannot of course be anything intelligent in Instinct ; but if we extend it as we must to the Logic of Feeling, the dispute will cease. 33. Neural processes which formerly were accom- panied by Consciousness sink into Sub-Consciousness, and on occasion re-emerge into distinct light of day. But even in the sub-conscious stage they are always sentient. The practice, too frequent, of speaking of actions as wwconscious, is more than a contradiction in terms. " Unfelt feelings " are altogether inadmissible. On the other hand, to speak of Consciousness (meaning thereby a particular aspect), as the substance of Mind, the universal condition of psychical phenomena, is also 142 PROBLEMS OF LIFE AND MIND. misleading. What is universal is the neural process, which on the subjective side is the sentient process. Sentience may assume the form of Consciousness, or the form of Sub-Consciousness; as Vision may take place when the central point of the retina is impressed, and then the effect is most distinct; or when any point of the area of the retina is impressed, and then the effect is less and less distinct as it is farther from the centre. Sentience is always sentient, as Vision is always visual. 34. The region of Sub-Consciousness is much the larger region. There is more heat than flame. The difference between them depends on the greater or less irradiation of an excitation. Here we may note two Psychodynamic laws, 1, of Irradiation, and, 2, of Eestriction. Although Anatomy, for its purposes, divides the nervous system into seve- ral different organs, this division is only an artifice, and must not permit us to overlook the cardinal fact that the nervous tissue is one, and has one general Property Neurility; and one general Function Reflexion. No stimulus can excite a single part of this whole without indirectly exciting all the other parts. Hence the law of Irradiation : every excitation must be propagated ; it cannot cease with itself, for this would violate the first law of motion. But the directions in which it will be propagated (the law of Eestriction here emerges) are determined by the struc- tural conditions at the time being. It is probable that irradiation is vague so long as it takes place through neuroglia* and becomes definite conduction w r hen it * Neuroglia is the name given by VIBCHOW to the interstitial sub- stance connedang the nervous elements nerve-cement. It is peculiarly PSYCHOLOGICAL PRINCIPLES. 143 is restricted in its course by the cells and fibres. Be this as it may, we must understand that while, accord- ing to the abstract law of Irradiation, every excitation is diffused throughout the tissue, terminating only in a muscular excitation, this diffusion is in effect always controlled by the law of Eestriction, and the pathway of discharge becomes more or less defined. The con- crete facts of excitation no more agree with the ab- stract law, than the actual motions of bodies agree with the abstract law of uniform rectilinear Motion. Every real excitation is subject to the statical conditions of the Organism at the time being ; that is to say, what are the lines of least resistance along which a motion will be propagated must necessarily be determined by the state of the structure at the time being ; any paths which have formerly been traversed by an impulse will be more ready to yield an issue to the new impulse. These formed paths therefore restrict the irradiation, which would otherwise be indefinite. 35. Many obscure facts receive their explanation through this law of Irradiation. Two only need here be specified for illustration : The fact that Extension is felt as a continuum, although the feeling arises from the excitations of discrete nerve-fibrils and discrete pulses on those fibrils, has greatly puzzled some in- vestigators, most of whom have been led to invent an extra-neural agency to explain it. Irradiation suffices, since by it there is a necessary blending of the discrete points, a fusion of the similar tremors. The second fact may be the obverse of this. It was interesting from its close resemblance to other connective tissues, since it is the link, so to speak, which enables us to understand how nerve- tissue arises. 144 PROBLEMS OF LIFE AND MIND. noticed by Aristotle that knowledge begins with vague conceptions, and increases with increasing definiteness in the conceptions. All impressions must at first be irradiated, and produce a chaos of vague sentience ; as these irradiations gradually become restricted, the pro- cesses are grouped, the paths are defined, distinctions are established. It is conceivable how differentiations in the tissue arise from differentiations of the pathways of discharge ; how the nerve cells and fibres, the magazines of con- ductible energy and the channels of conduction, arise amid the neuroglia; and how old age or disease in- creasing the relative proportions of neuroglia and nerve elements reduces the mental functions to infantile or imbecile states ; finally, how the tendency of Kestric- tion is, as old age advances, to prevent new acquisi- tions, and resist new combinations. 36. Although when viewed synthetically every sen- sation, every perception, every conception is an unit, viewed analytically, and genetically, it is a compound. There is no single sensation which is an element, i.e., irreducible. This is to be considered in reference to the disputes respecting the unity of Consciousness, the simplicity of the Ego. Every act of Consciousness is one ; every Ego is an unity. But analysis which resolves a sensa- tion into its constituent neural elements, resolves Con- sciousness into its constituent processes, and the Ego into a consensus of psychical activities. The demon- stration that thinking is seriation, and that a series involves Time, disproves the notions of ultimate unity and simplicity assigned to a Thinking Principle. In any positive meaning of the term, that Principle is not PSYCHOLOGICAL PRINCIPLES. 145 an antecedent but a resultant, not an entity but a con- vergence of manifold activities. 37. This convergence is a necessary consequence of the synergy of the organs dependent on Irradiation. The seriation depends on the law of Keinstatement or Reproduction, by which one neural process tends to re-excite those processes which formerly were excited in conjunction with it, or which are anatomically linked with it. Those pathways of discharge which were once determined by the combined action of the stimulus and reaction of the Organism are the path- ways which will be statically connected, and hence they will form the lines of least resistance along which any fresh excitation will pass. 38. But this law of Reinstatement whereby one feeling calls up associated feelings, is itself only the expression of the statical conditions. We are not therefore to expect that a given stimulus will always re-excite a given group of feelings ; we can only formu- late the general tendency* in virtue of which a sen- sible stimulus draws with it fainter feelings of previous impressions, so that they are grouped into a judgment or perception. This group is, in turn, the element of some wider group, whenever it is not directly reflected in discharge on some organ. But in all cases an action of some kind results ; directly or indirectly, every sensation is completed in an action; and thus Ac- tion is the pole-star of even the most wide-wandering Speculation. 39. Thus the three terms of the progression from * Tendency is the ideal summation of the statical conditions which tend to a dynamical result ; or, to express it less technically, it is one gathering up into a picture of all the events which we foresee will succeed each other when the organism is set going, and of the final result. VOL. I. K 146 PROBLEMS OF LIFE AND MIND. Stimulus to Reflex, are respectively, Feeling, Logic, and Action ; or Impulse, Guidance, and Result. Let me again remind the reader that he is by no means called upon to adopt the foregoing conclusions until he has had laid before him in detail the ana- tomical, physiological, and psychological evidence. There is much that will no doubt seem inadmissible, much questionable. He is only asked to accept what- ever he can, and to suspend his judgment on the rest. I will now state a principle which hereafter will be extensively applied. It wears so paradoxical an air, that I should not venture to bring it forward until the evidence had been duly exhibited, but that the explicit announcement here will protect me against a possible anticipation on the part of some other writer. While lingering over the execution of the present work, I have more than once had the mingled pleasure and pain of rinding results I had laboriously reached, arrived at by other writers ; and as I believe that the Psychological Spectrum is physiologically demonstrable, the possibility of some one else discovering it is worth taking into account. THE PSYCHOLOGICAL SPECTRUM. 40. Briefly, then, the principle may thus be formu- lated. The optical spectrum is constituted by three funda- mental colours : red, green, and violet, which are due to three modes of vibration affecting the rods and cones of the retina, or perhaps to three different sets of rods and cones ; and each sensation of an individual colour depends on the proportions in which these modes the number of pulses in a second affect the retina. Each PSYCHOLOGICAL PRINCIPLES. 147 colour also contains all the characteristic vibrations of the others, and consequently each colour owes its indhiduality, not to vibrations which the others want, but to a predominance in a certain order of vibra- tion. Thus there is a special rapidity in the pulses on the retina in the waves producing red ; but in every red there are waves of fainter rapidity such as produce green and violet when they are dominant. In the colour green, there are likewise the red and violet waves; in the colour violet, there are red and green waves. 41. The analogy of Vision and Consciousness, so usefully employed by many writers, may justify my use of the term the Psychological Spectrum, which likewise is constituted by three fundamental modes of excitation : namely, Sensation, Thought, and Motion. I shall show that these three orders, of nervo-muscular excitation are involved in every sensation, perception, image, or con- ception ; and of course also in every emotion, desire, volition, &c. In other words, the psychical process is everywhere a triple process. Every psychical fact is a product of sense- work, brain- work,, and muscle- work. Each sentient phenomenon (perception, emotion, con- ception, or volition), is individualised by, and receives its specific character from the predominance of one of the three orders ; and one feeling is distinguished from another of the same kind by quantitative differ- ences in their constituent units. All varieties among the several mental states are due to the varying degrees of energy with which Sensation, Thought, and Motion co-operate. Each mental state is thus a function of three variables* * Combining this conception with FECHNER'S law of the proportionality 148 PROBLEMS OF LIFE AND MIND. 42. Leaving this to the reader's meditation, I now pass to the consideration of another result of the law of Eeinstatement, which law is another aspect of the law of Kegistration. A sensation or perception once produced, may of course be reproduced by a recurrence of the original conditions ; but it may also be reproduced with fainter energy, as an image, when the original objective conditions are absent, and only the subjective conditions are present in the modifica- tion of structure. That is to say, the original feeling is registered in the organism as a modification, and whenever this neural tract which was originally in action, is again excited, the old feeling will be rein- stated. The sight of an orange thus recalls the asso- ciated feelings of taste and smell, and perhaps of the person who gave the first orange, or the plate on which it was handed. In this series the visual sensation is directly reproduced under conditions closely resembling its original production; therefore the energy of this feeling is incomparably greater than that of the in- directly reproduced feelings of smell, taste, &c. What- ever antecedent may stimulate the neural tracts, any one of these may re-excite the others. Thus the mere name of the person, or the place, the sight or sound of the word ' orange/ will suffice. 43. All sentient acts are acts of Presentation or of Re - Presentation, usually called Sensation and Idea. of sensation to stimulus, the reader may perhaps seize my meaning when I said (Introd., 12) that the Differential Calculus might some day be applied to Psychology. Another indication is furnished by HELMHOLTZ, when he assumes that the local feelings derived from the different points in the retina more closely resemble each other the closer the points are, so that the kind of local feeliiig is a continuous function of the co-ordinates of the retinal points. Physiol. Optik, p. 800. PSYCHOLOGICAL PRINCIPLES. 149 The Germans distinguish the directly excited feeling as ' the feeling in us ' Empfindung ; and the indirectly excited feeling as ' the placing before us ' Vorstellung. We have no such happy terms, but Sensation and Image, or Idea, serve pretty well. The sensation, or presentation, is fitly considered real, because it has objective reality (res) for its ante- cedent stimulus. The re-presentation, whether image or symbol, is ideal, because its antecedent is a subjective state. Eeality always indicates that antecedent which excites sensation when in direct relation with the sensory organism. Hence we say that a feeling is real when it is felt, ideal when it is only thought, not felt. To feel cold, and to think of cold, are two markedly different states. 44. An image, therefore, being a representation, a Vorstellung, an indirectly excited feeling, may be called the ideal form of a sensation. It ia a transition between the pure real and the pure ideal, i.e., between sensation and symbol. Because of its connection with sensation, it passes into pure sensation when the energy of its tremors is greatly increased ; as in Hallucination, wherein the feeling, although excited by internal stimuli, having its antecedent in a subjective state and not in some objective res, does assume all the energy of a sensation objectively excited. We may consider the gradations of Sensation, After-sensation, Imagination/ 55 " and Hallucination, as the varying energies of the same neural tracts. Owing to the indirect, representative origin of Ima- gination and its ideal character, there are important * This word must be understood literally, i.e., as the image-forming process ; not metaphorically, as the poet's phantasy. 150 PROBLEMS OF LIFE AND MIND. differences between it and Sensation, and After-sen- sation ; one of these being that Images are facultative, and are thereby capable of entering into intellectual constructions. 45. Sensation, Perception, and Imagination, all in- volve the co-operation of the Logical or Grouping ele- ment, whence Judgment, and of the Motor element, whence Action (41). By including under these rubrics the phenomena of Cognition and Conation, and treating in due order the Appetites, Emotions, and Volitions, we shall exhaust the Biological Data of Psychology, if to this examination of the structure and functions of the Animal Organism in detail we add a consideration of it as a Whole. From this point of view we must con- sider certain general results. 46. Of these general results perhaps the most per- plexing, as it assuredly is the most interesting, is Consciousness, which may be pictured as the mass of stationary waves* formed out of the individual waves of neural tremors. Next comes what may be * Stationary waves play a great part in the speculations of modern physicists. They may be thus illustrated. If the surface of a lake is set in motion by the various streams which enter it from various points, each stream diffuses waves over the surface, and these finally reach the shores, whence they are reflected back towards the centre of the lake. The re- flected waves meet with new incoming waves, and the product of the two is a stationary wave, forming, so to speak, a pattern on the surface. This pattern is of course a fluctuating figure depending on the concurrent waves. Now whena/resA stream enters the lake its waves will at first pass over this pattern of stationary waves, neither disturbing nor disturbed ; but after reaching the shore they will in turn be reflected back towards the centre, and there mingling with incoming waves from the same source, they will, according to circumstances, either markedly alter the pattern of the stationary waves, or modify it but slightly : analogically, in the one case there will be an appreciable change in Consciousness, in the other none. PSYCHOLOGICAL PRINCIPLES. 151 called the psychical mood or attitude. Each individual feeling has its special signature, so likewise the resultant general feeling has its signature ; and we are at each moment conscious of a vague massive feeling of comfort or discomfort, exhilaration or despondency, joy or grief, fear, rage, kindness, &c. There is also a logical attitude which is called Attention, itself the product of feeling, and one of the necessary factors in Perception. 47. When this survey has been completed we have the final task of exhibiting how the sentient phe- nomena may be explained by neural phenomena. The structure and action of the Organism have to be psy- chologically interpreted. This will require a new anatomy of the nervous system. What now exists, although of immense value, is defective in many respects. Not only must each function be traced to its special organ ; and the part played by each constituent assigned to it; not only must the connection of the parts be displayed, but there must be taken into account the very important element of Vascular Irrigation. The distribution of the arteries is an essential element in the biostatical estimate. Arterial territories have to be defined. Many individual variations in mental character depend on the variations in the calibre of the cerebral and carotid trunks and many variations in the intellectual, emotive, and active tendencies depend on the relative importance of the cerebral and carotid trunks. The energy of the Brain depends mainly on the calibre of its arteries ; the special directions of that energy depend on the territorial distribution. 48. But when this programme is thoroughly worked out, it will only present one half of Psychology. It will embrace the Logic of Feeling, common to animals 152 PKOBLEMS OF LIFE AND MIND. and to man, but it will still leave undeciphered that which constitutes the wonder and glory of man, his intellectual and moral life. Rising out of the Logic of Feeling there is the Logic of Signs, which is to the former what Algebra is to Arithmetic ( 25). Rising out of the Animal Organism there is the Social Organ- ism, the collective life of all the individual lives ; and if we desire to decipher Human Psychology we must study the Human Organism in its relations to the Social Medium as well as in its relations to the Cosmos. THE SOCIOLOGICAL DATA. 49. It is now almost universally admitted that animals and men having similar structures must have similar functions ; and further, that the mental mani- festations being determined by organic structures, the mental functions of animals and men must be essen- tially similar. That animals have sensations, appe- tites, emotions, instincts, and intelligence that they exhibit memory, expectation, judgment, hope, fear, joy that they learn by experience, and invent new modes of satisfying their desires, no philosopher now denies. And yet the gap between animal and human intelligence is so wide that Philosophy is sorely puzzled to recon- cile the undeniable facts. When it was customary to attribute to Instinct all the manifestations of In- telligence in animals, and to Reason all the similar manifestations in men, this difficulty was not felt A phrase did duty for an explanation. To say that man was endowed with a Rational Soul, inhabiting the organism yet independent of it, and altogether distinct from the Vegetative Soul which ruled the body, seemed an easy way of accounting for all the observed facts. PSYCHOLOGICAL PRINCIPLES. 153 50. Untenable as this hypothesis is, I am disposed to regard it with more favour, in some respects, than the crude materialist hypothesis ; for I, too, hold that the superiority of human Intelligence is due to the presence of an important factor, one wholly wanting in the animal. Instead of regarding the differences between man and animal simply as differences of degree, I hold that by no conceivable extension of animal faculties, unaided by this important factor, could the highest of the animals be raised into that moral and intellectual world which is the habitual medium of the civilised human soul. Believing, as I believe, in the evolution of the higher from the lower, and disbelieving therefore in any abrupt break in the continuity of evolution, I still say that in so far as- we are justified in classing phenomena into distinct groups, and thus distinguish- ing the products of complex factors from the products of simpler factors, the group recognised under the class ' Human Intelligence ' is so different from the group 'Animal Intelligence' that it requires for its analytical interpretation different factors of corresponding import- ance. The circle and the ellipse are different figures, the former having but one centre with all its radii equal, the latter having two foci and unequal radii. Circles differ from circles in degree; they differ from ellipses in kind. Whether large or small the circle has the same properties, and these are different from the properties of the ellipse. It is true that by insensible gradations the circle may flatten into an ellipse, or the two foci of the ellipse may blend into one, and form a circle. But so long as there are two foci, the ellipse has its characteristic properties. In like manner the boundaries of the animal and human may be found 154 PROBLEMS OF LIFE AND MIND. insensibly blending at certain points; but whenever the 'animal circle* has become transformed into the c human ellipse/ by the introduction of a second centre, the difference ceases to be one of degree, and becomes one of kind, the germ of infinite variations. The question arises : What are these respective foci \ What are the respective centres of animal and human Intelligence ? I answer : the Logic of Feeling and the Logic of Signs ; or, in more familiar terms, Feeling and Thought : the one belonging to the Animal Organism, the other rising out of this and out of the Social Organism. 51. The answers hitherto propounded have been either founded on the spiritualist hypothesis, endowing man with a Soul of spiritual structure ; or on the biological hypothesis (materialist or not), deducing all the mental phenomena from the animal functions in adaptation to the Cosmos. Eminent thinkers still cling to some form or other of the spiritualist hypothesis, repelled from the biological hypothesis by their sense of its inadequacy. They admit that all our bodily functions depend on bodily organs. They admit that among these functions are those of Feeling with its varieties and complications. But they also know that animals having organs closely resembling our own, and feelings closely resembling our own, have little or nothing of the highest order of mental activity : Animals are intelligent, but have no Intellect ; they are sympathetic, but have no Ethics ; they are emotive, but have no Conscience. When it is said that Animals however intelligent have no Intellect, the meaning is that they have per- ceptions and judgments but no conceptions, no general PSYCHOLOGICAL PRINCIPLES. 155 ideas, no symbols for logical operations. They are in- telligent, for we see them guided to action by Judg- ment ; they adapt their actions by means of guiding sensations, and adapt things to their ends. Their me- chanism is a sentient, intelligent mechanism. But they have not Conception, or what we specially designate as Thought, i. e., that logical function which deals with generalities, ratios, symbols, as Feeling deals with par- ticulars and objects a function sustained by and sub- servient to impersonal, social ends. Taking Intelligence in general as the discrimination of means to ends the guidance of the Organism towards the satisfaction of its impulses we particularise Intellect as a highly differ- entiated mode of this function, namely, as the discrimi- nation of symbols. This differs from the rudimentary mode, out of which it is nevertheless an evolution, as European Commerce differs from the rudimentary Bar- ter of primitive tribes. Commerce is impossible except under complex social conditions out of which it springs ; and its operations are mainly carried on by means of symbols which take the place of objects : the bill of invoice represents the cargo ; the merchant's signature represents the payment. In like manner Intellect is im- possible until animal development has reached thehuman social stage ; and it is at all periods the index of that development ; its operations are likewise carried on by means of symbols (Language) which represent real objects, and can at any time be translated into feelings. 52. It is obvious that the biological data can only resolve one half of the psychological problem, only present one of the foci of the ellipse, since by no derivation from the purely statical considerations of man's animal organism can we reach the higher dy- 156 PROBLEMS OF LIFE AND MIXD. namical products. Isolate man from the social state, and we have an animal ; set going his organism simply in relation to the Cosmos, without involving any rela- tions to other men, and we can get no Intellect, no Conscience. Whence are these derived ? The organism of the anthropoid apes is very little differenced from ours; their sensory organs, nay, even their brain (the so- called 'organ* of the mind), can be distinguished from ours only by trifling deviations ; but with this external structural resemblance, what an infinite mental dis- parity ! Biology forces us to seek for a status corre- sponding to this diversity. Between the various types of vertebrate structure there are gradations; but between the vertebrate and invertebrate there is a gap. The internal skeleton characteristic of the Vertebrate is approached in the Cephalopoda; the symmetrical ar- rangement of nerve-centres is seen in the Articulata ; but in spite of these and other indications of a general resemblance, the marked types, Vertebrate and Inver- tebrate, stand out distinct. So between the extremes of human Intelligence say a Tasmanian and a Shak- speare there are infinitesimal gradations, enabling us to follow the development of the one into the other, without the introduction of any essentially new factor. But between animal and human Intelligence there is a gap, which can only be bridged over by an addition from without. That bridge is the Language of symbols, at once the cause and effect of Civilisation. 53. The absurdity of supposing that any ape could under any normal circumstances, construct a scientific theory, analyse a fact into its component factors, frame to himself a picture of the life led by his ances- tors, or consciously regulate his conduct with a view PSYCHOLOGICAL PRINCIPLES. 157 to the welfare of remote descendants, is so glaring, that we need not wonder at profoundly meditative minds having been led to reject with scorn the hypothesis which seeks for an explanation of human Intelligence in the functions of the bodily organism common to man and animals, and having had recourse to the hypothesis of a spiritual agent superadded to the organism. 54. Yet the spiritual hypothesis is scientifically un- tenable. It is an imaginary hypothesis, and has not only the defect of being incapable of verification, it has the more serious defect of being incapable of extending our insight : it gives a name to the facts observed, it throws no light on them, connecting them with others; nor does it enable us to discover unsuspected relations. Further, it is the introduction of an unknown to take the place of a Tcnowable. The spirit is proposed as an agent ; yet of its nature, and agency, we know abso- lutely nothing. And if, for the sake of argument, we grant the exist- ence of a spirit, and accept it as the agent, the same objection rises against it which rose against the mate- rialist hypothesis, namely, that it fails to cover the facts. Man, possessing this spirit but isolated from Society, could no more manifest the activities classed under Intellect and Morality than the animal could. He would still require that his Spiritual Organism should be in relation to the Social Medium. For one thing he would be without the mighty instrument Language, which we shall prove to be indispensable to the creation of abstract Thought. He would only have perceptions, and the Logic of Feeling ; he would be without con- ceptions, and the Logic of Signs. Then, again, he would have none of the many needs which arise from 158 PROBLEMS OF LIFE AND MIND. social relations ; nor the accumulation of experiences which form the material of scientific evolutions. This is demonstrable from many sides. Here we simply note the fact that our intellectual wealth is not only capitalised Experience, but is always in strict accord with social development ; so that the savage is not less incompe- tent than the animal to originate or even understand a philosophical conception ; the peasant would be little better than the ape in presence of the problems of abstract science ; and it would be hopeless to expect either of them to weigh the stars, or to understand the equations of curves of double curvature. Nor are the moral conceptions of the savage much higher than those of the animal. His language is without terms for Jus- tice, Sin, Crime : he has not the ideas. He understands generosity, pity, and love, little better than the dog or the horse does. His intelligence is mainly confined to perceptions and sentiments. His aims are almost all immediate and practical, rarely remote, never theoreti- cal. The most intelligent inhabitants of Guiana, though far removed from primitive savagery, could not believe that Humboldt had left his own country and come to theirs "to be devoured by mosquitos for the sake of measuring lands which were not his own." There is a further ground, still more decisive, against the spiritualist hypothesis, namely, that we have no need of an imaginary agent to explain what can be perfectly explained by a real agent the Social Organism. Not having this conception, the spiritualists imagine that to deny the existence of the Spirit is to deny the existeoce of the Soul. It is no more a denial of the Soul, than the rejection of the old hypothesis of a nervous fluid was a denial of nervous physiology. All the facts of PSYCHOLOGICAL PRINCIPLES. 159 Consciousness, all the marvels of Thought remain, whatever changes may take place in our theories re- specting them. It is scarcely necessary to add that bio- logists may quietly disregard the common rhetorical objection against their " mechanical views," as if such views were self-condemned. No sooner does any phi- losopher attempt to substitute clear conceptions of the processes of Nature* for vague speculations incapable of verification, than the framers of such speculations and the acceptors of them with one accord exclaim : " This is degrading human nature ! " as if to leave men in ignorance were to sustain them in their dignity. 55. If man is a social animal, which is undeniable, the unit in a living whole, just as any one organ is the unit of an organism, obviously his functions will be determined not only by his individual structure, but also by the structure of the Collective Organism. The functions of the liver, or of the kidneys, are determined partly by their structure, partly by influences from the other organs. Man's individual functions arise in rela- tions to the Cosmos; his general functions arise in relations to the Social Medium; thence Moral Life emerges. All the animal Impulses become blended with human Emotions. In the process of evolution, starting from the merely animal appetite of sexuality, we arrive at the purest and most far-reaching tender- ness ; from the merely animal property of Sensibility we arrive at the noblest heights of Speculation. The Social Instincts, which are the analogues of the individual Instincts, tend more and more to make Sociality domi- nate Animality, and thus subordinate Personality to Humanity. 56. All the attempts to explain Mind without taking 160 PROBLEMS OP LIFE AND MIND. the social factors into account have been signal failures ; but especially mistaken have been the estimates vainly founded on anatomical data, and above all on the measurements of crania, and the weighing of brains. The spiritualists were more philosophical in demand- ing another agent and another test. The anatomical estimates proceed on three assumptions generally re- garded as axioms, 1, that the brain is the "organ of the Mind ; " 2, that the mental diversities observable between men and animals, and between different races of men, are due solely to differences of cerebral mass ; 3, that these diversities can be approximately esti- mated by estimates of volume and weight. We must reject all three. The first, because to seek for an organ of the Mind is not less preposterous than to seek for an organ of the Life. Nor is this difficulty avoided by those who regard the brain simply as the organ of the Intellect ; for the Intellect is also an ab- straction, and if we reduce the abstraction to its con- cretes we have acts which involve sensory and motor organs, and groupings of their reactions. The brain may be the organ in which sensory processes are finally grouped before they are reflected on other organs ; but it is only in artificial analysis that we can consider the process of grouping independently of the materials grouped. Let us, however, for a moment grant that the brain is the organ of the Mind ; this will not justify the second assumption. No one will suppose that I deny the cerebral structure to be one of the determi- nants in all mental manifestations ; but the same sci- entific evidence which necessitates this conclusion, ne- cessitates the rejection of that precipitate conclusion which assigns the whole product to one of its factors PSYCHOLOGICAL PRINCIPLES. 161 The co-operation of the Medium is not less indispens- able than that of the Organism ; and, in the case of man, the Medium is constituted by the education of the race and of the individual ; so that the state of social evolution which has been reached at any given time in any given place, will be one of the necessary determinants in every individual mind. I shall recur to this presently ; here it is enough to point out that admitting the general mental resemblances, depen- dent on community of structure and of the general Medium, we cannot assign the diversities of the mental manifestations of such common powers to structural differences alone. Every organism has not only an inherited and gradually modified structure which is one of the determinants of its history, it has also a history of incident, that is of transient con- ditions, which may lead two similar organisms along divergent paths, and determine them to different maoifestations. And this leads me to the third assumption. The differences of cerebral structure which are evolved in the education of the race, and which are necessary conditions of the observed diversities in mental mani- festation, can no more be estimated by measurements of volume and mass, than the skill of a Joachim, as distinguished from that of an old crowder playing a popular jig, could be estimated by taking the size and weight of his arms and fingers. 57. We return then to our position that Mind can- not be explained without constant recognition of the statico-dynamical relations of Organism and Social Medium. To understand the first we must regard it physio- VOL. I. L 162 PROBLEMS OF LIFE AND MIND. logically and anatomically. It is not a passive recipient of external impressions, but an active co-operant. It has not only its own laws of action, but brings with it that very elementary condition of Consciousness which most theorists attempt to derive ab extra. I mean that the sensitive mechanism is not a simple mechan- ism, and as such constant, but a variable mechanism, which has a history. What the Senses inscribe on it, are not merely the changes of the external world ; but these characters are commingled with the characters of preceding inscriptions. The sensitive subject is no tabula rasa: it is not a blank sheet of paper, but a palimpsest. The sensational school was strangely blind to the very conditions of the results it in- tended to explain. It treated Thought as 'trans- formed Sensation,' without seeing that the presence of the grouping faculty, on which Thought depends, was necessary both for the Sensation and for the trans- formation. Not aware of the fact that the Organism is an evolution, bringing with it, in its structure, evolved modes of action inherited from ancestors, these writers overlooked the fact that the Organism brings with it inherited Experience, i.e., a mode of reaction antecedent to all direct relation with external influences, which necessarily determines the results of individual Experience. There is thus what may be called an d priori condition in all Sensation, and in all Ideation. But this is historical, not transcendental: it is itself the product of Experience, though not of the individual. Our perceptions are evolutions ; and, having necessarily a history at their back, it is clear that all perceptions are modified by pre-perceptions, all conceptions by pre- conceptions. Hence mental diversities. PSYCHOLOGICAL PRINCIPLES. 163 58. We are not, however, to conclude that this d priori condition is metempirical. It is an inheritance of acquired modification. It may, analytically, be separated from the d posteriori experiences, as the Organism may, analytically, be separated from its functions ; and in this k way we may accept Kant's position that the d priori Forms of Sense and Under- standing render Experience possible. But this is only saying that function is determined by structure ; and we must wholly reject his position that these Forms are transcendental, and are not only antecedent to and independent of all Experience whatever, ancestral and individual, but are sources of a higher truth than can be gained through individual experiences. They are congenital modifications, and are d priori because congenital. 59. It is important here to remark, that while func- tion is necessarily determined by structure being no- thing but the structure in action co-operating with the medium the transmission from generation to genera- tion is confined to the structural modification, not including the incidents which caused that modification, nor any of the special actions which were the products of that modification in combination with special inci- dents. What we inherit is the modified structure, and, with that, the aptitude to act in a certain way under certain stimuli ; but the inheritance of the historical result is not the inheritance of the incidents which severally converged to that result, nor of the conse- quences which issued from the result under special con- ditions. Thus the tissue of the lungs subjected to certain influences becomes so modified that tubercle is formed. The child may inherit a tuberculous diathesis, 164 PROBLEMS OF LIFE AND MIND. but cannot inherit the causes which originated the tubercle, nor the peculiar mental experiences which re- sulted from the influence of tubercle in the parent organism ; these being due to a complex of conditions never recurring in the child's experience. In discussions on Heredity it has not been sufficiently recognised that only results can be inherited, and that every modification of structure is the issue of many complex experiences. Could one experience be isolated from prior and posterior experiences, it might be trans- mitted from parent to child; but each experience is not only complicated by prior experiences, its transmission is complicated by the influence of the other parent. A musical aptitude will be inherited, but no particular melody. The aptitude represents a modification of structure whereby the response to auditory stimuli takes a melodic form ; but any particular melody is the form which this general aptitude takes under very special and complez conditions. In other words, the inherited organism is predisposed to play tunes of a certain character, but the music it will give forth must depend on the player. Here once more we see the neces- sity of allowing for the objective factor no less than for the subjective factor. Certain external influ- ences co-operating with the organism have modified the structure of that organism, and produced what may be called a musical instrument ; could the external influ- ences which were originally grouped into a definite melodic form be repeated, the result would be repeated, and the musician's child would again create de novo the melody created by his parent. The chances are infinite against such a recurrence in the order of the stimuli. But there are, in other regions, necessary re- PSYCHOLOGICAL PRINCIPLES. 165 currences in the order, so that every mind rediscovers the most general truths for itself, because every mind has presented to it the same phenomena in the same order. 60. This is a biological doctrine of Innate Ideas, which we shall have presently to consider at length. Here we must be content with saying that in the old meaning the doctrine is untenable. There are no in- nate ideas, no innate truths, no thoughts having a metempirical source simply innate tendencies, con- genital aptitudes, which cause us to respond in certain ways to certain stimuli ; but if the stimuli differ in kind, or in degree, or in their order of presentation, the responses must proportionately differ. In this sense we have Moral and Intellectual In- stincts the action of congenital arrangements in the mechanism when set going under appropriate stimuli. Thus defined, it is clear that we are born with Logical Instincts. Strictly speaking, we no more learn to reason than we learn to see. In one sense we learn both, since Experience (the action and reaction of Organism and Medium) is requisite for both ; and in both we have to acquire what is but partially given at birth namely, the structure capable of co-ordinating impressions. What we learn, what we acquire, both in reasoning and vision, is the result of the aptitudes evolved through external influences acting on a primitive arrangement of nervous tissue. If any one contemplating the infant, so obvi- ously incapable of seeing or of reasoning, should demur to our presentation of Eeason as congenital, he must equally demur to the universal acceptance of the sexual instinct as congenital ; all three functions are only con- genital in the sense in which the oak is said to lie ready 166 PROBLEMS OF LIFE AXD MIND. . in the acorn. The oak will not be developed unless under the appropriate conditions, and every variation in the soil or atmosphere will impress corresponding variations on the structure of the developed product. But the acorn inherits certain structural tendencies, which will manifest themselves in definite forms. The nervous organism also inherits certain tendencies, and whether these are early or late in evolution is quite a subsidiary consideration. 61. Our activities are of two classes the personal and impersonal. The personal comprise Sensation, Per- ception, Imagination, Judgment, Volition, all directed to the satisfaction of egoistic impulses or primary needs : the need of Food, of Exercise (with its correlative, Ke- pose), of Expression, and of Eeproduction. The imper- sonal are directed to the satisfaction of sympathetic impulses the need of Affection, and the need of Know- ledge. Intelligence, in the one case, is the conquest of means for immediate ends ; Intellect, in the other, is the conquest of means for remote ends. The animal has sympathy, and is moved by sympa- thetic impulses, but these are never altruistic ; the ends are never remote. Moral life is based on sympathy : it is feeling for others, working for others, aiding others, quite irrespective of any personal good beyond the satisfaction of the social impulse. Enlightened by the intuition of our community of weakness, we share ideally the universal sorrows. Suffering humanisea Feeling the need of mutual help, we are prompted by it to labour for others. The egoistic impulses are directed towards objects simply so far as these are the means of satisfying a desire. The altruistic impulses, on the contrary, have greater need PSYCHOLOGICAL PRINCIPLES. 167 of Intelligence to understand the object itself in all its relations. Hence so much immorality is sheer stupidity. 62. Thus it is that we are to seek in the Social Organism for all the main conditions of the higher functions, and in the Social Medium of beliefs, opin- ions, institutions, &c., for the atmosphere breathed by the Intellect. Man is no longer to be considered simply as an assemblage of organs, but also as an organ in a Collective Organism. From the former he derives his sensations, judgments, primary im- pulses; from the latter his conceptions, theories, and virtues. This is very clear when we learn how the In- tellect draws both its inspiration and its instrument from the social needs. All the materials of Intellect are images and symbols, all its processes are operations on images and symbols. Language which is wholly a social product for a social need is the chief vehicle of symbolical operation, and the only means by which Abstraction is effected. Without Language there can be no meditation ; no theory ; no Thought, in the special meaning of that term. A perception condenses many feelings into one, and is so far knowledge. A word the symbol of a conception condenses many perceptions into one ; and is thus not only knowledge of a wider range, but is a knowledge which is faculta- tive, and capable of transmission and preservation. 63. Language is the creator and sustainer of that Ideal World in which the noblest part of human activity finds a theatre, the world of Thought and Spiritual Insight, of Knowledge and Duty, loftily elevated above that of Sense and Appetite. Into this Ideal World man absorbs the universe as in a Transfigura- 168 PROBLEMS OF LIFE AND MIND. tion. It is here that he shapes the programme of his existence ; and to that programme he makes the Real World conform. It is here he forms his highest rules of Conduct. It is here he plants his hopes and joys. It is here he finds his dignity and power. The Ideal World becomes to him the supreme Reality. It multiplies his pleasures and his pains. Its phantoms haunt him filling life with infinite misery, such as never troubles less gifted creatures : setting tribe against tribe, brother against brother, father against son, spreading bitter hate and the intolerable tyrannies of Superstition. Its phantasies animate him filling life with infinite and subtle joy, and in many ways aggran- dising his capacities and aims. This is man's spiritual being; who would renounce it for the comparative calm of the most fortunate brute? 64. An animal suffers from a physical calamity, seeks to escape from it, but never seeks to understand and modify its causes. The savage also suffers, and seeks to escape. But he wonders ; speculates on the causes; hopes to master them by invocations or in- cantations. The civilised man tries to understand the causes that he may modify them when they are modifiable, and resign himself to them when they are unmodifiable. The animal has only the Logic of Feeling to guide his actions. He observes and con- cludes, never explains. The man has besides this, the Logic of Signs : he observes, and explains the visible series by an invisible series. The one has only know- ledge of particular facts; the other a knowledge of general facts. The knowledge of the one is fixed, that of the other facultative. -Between the Logic of Feeling and the Logic of PSYCHOLOGICAL PKINCIPLES. 169 Signs we must intercalate the Logic of Images, since the passage from Perception to Conception is effected through Imagination. Images, although reproductions of perceptions, possess a property not possessed by perceptions, namely, that of facultative reproduction, which enables them to be abstracted from the sensible order of presentation, and combined and recombined anew. Animal Imagination is reproductive but not plastic : it never constructs. 65. It is in Imagination that must be sought the first impulse towards Explanation; and therefore all primitive explanations are so markedly imaginative. Images being the ideal forms of Sensation, the Logic of Images is the first stage of intellectual activity; and is therefore predominant in the early history of individuals and of nations. The first attempts to ex- plain a phenomenon must be to combine the images of past sensations with the sensations now felt, so as to form a series. In the next stage, words, repre- sentative of abstractions, take the places both of images and objects. Thus the Logic of Signs replaces the Logic of Images, as the Logic of Images replaced the Logic of Sensation. Imagination precedes Science : Poetry precedes Prose : Ornament precedes Comfort. 66. The Logic "of Signs is a higher development of the Logic of Feeling, but its processes are similar. The differences do not spring from the laws of neural group- ing, but from the groups that are grouped. Sensations are groups of neural tremors ; perceptions are groups of sensations; therefore Perception may be styled con- struction in the sphere of Sense. Intuitions are per- ceptions of relations ideal observation. Conceptions are groups of intuitions symbolised in words. Con- 170 PROBLEMS OF LIFE AND MIND. ception therefore may be styled construction in the sphere of symbols. But symbols are representatives of values ; it is only by their possible reduction to Reals i.e., to feelings that their employment can be justified. A bank-note is a symbol representing so much gold, which in turn represents so much food or labour. "But it is always assumed that the bank is solvent, and that gold is a current article of exchange. A forged note, or a note issued by an insolvent bank, may pass from hand to hand, but its final object is not accomplished. Thus all our reasonings by means of symbols proceed on the assumption that the symbols can at any time have their values assigned, and that they represent Eeals, which will excite feelings. Our perceptions proceed on the assumption that the qualities not felt, but inferred to be coexistent with those now felt, do really coexist as virtual feelings, to become actual feelings when the object is brought into direct relation with the respective Senses. 67. The Real is that which is felt. An object is to us what it is felt or thought by us. Knowledge is virtual Feeling : it is pre-vision of what will be vision, under sensible conditions, because it, or something like it, once was vision. Theory is virtual Experience, re- producing past experiences, and anticipating the effects of real presentation. Sensation and Intuition always carry Belief. In- ference is Expectation, or qualified Belief. We cannot resist belief in a sensation, though we may doubt any of the inferences it awakens. We cannot resist belief in an intuition, though we may doubt whether the re- PSYCHOLOGICAL PRINCIPLES. 171 lations intuited be real or not. In the act of intuiting, our feeling of security is undisturbed. The distinction between Observation and Inference is the distinction between the real and ideal, the actual and virtual. But in point of fact pure Observation i. e., sensation wholly unmingled with Inference is impossible ; it is so by the Laws of Reinstatement. Pure Theory i.e., logical combination of relations un- mingled with related terms is also impossible. 68. The purpose of Intelligence being to direct our impulses towards their satisfaction, and the purpose of the Intellect being to accomplish this through a wider survey of means and possibilities, we learn how on the one hand a]l Intelligence must have its final test in Reality, and on the other how the Intellect, which is the highly developed form of Intelligence, has erected means into ends, and now pursues these proximate ends in oblivion of the ultimate end, and will even sub- stitute fictions in place of facts, abstract types for con- crete things. The direct object of the Intellect is not Reality; that, however, is its ultimate object. The progress of development is an ever-increasing tendency towards more and more remote conceptions and indirect methods, detaching the mind more and more from sensible observation. It may be illustrated by the stages of numerical calculation. Man begins by count- ing things, grouping them visibly. He then learns to count simply the numbers, in the absence of the things, using his fingers and toes for symbols. He then sub- stitutes abstract signs, and Arithmetic begins. From this he passes to Algebra, the signs of which are not only abstract but general ; and now he calculates numerical 172 PROBLEMS OF LIFE AND MIND. relations, not numbers. From this he passes to the higher calculus of relations of relations. It is the same with the development of Commerce. Men begin by exchanging things. They pass to the exchange of values. First money, then notes or bills, is the symbol of value. Finally, men simply debit and credit each other, so that immense transactions are effected by means of this equation of equations. The complicated processes of sowing, reaping, collecting, shipping, and delivering a quantity of wheat, are con- densed into the entry of a few words in a ledger. 69. In consequence of this development of Intel- lect i.e., of the interest in remote means substituted for direct ends man acquires his immense superiority over animals in achieving the final end. It is thus, and thus only, that he is enabled to modify the course of events. It is thus that Sentience becomes Science, facts are condensed into laws, and direct vision is mul- tiplied and magnified by remote pre- vision. But while insisting on the claim of Intellect to pursue its ideal objects, and to be uncontrolled in its prosecution of even the remotest research, we must never forget that its ideal ends are only sanctified by the final end by that correspondence with Reality which was its starting-point and must be its goal. No speculation, however wide of actual experience, can be valueless, if, in any way, it enlarge our vision of the Real ; but this is its final test. If with mighty span of wing it soar above the sphere of the Real, it must not keep hovering there, but must at some point re-enter the sphere. Ideal construction is unlimited in freedom, on the understanding that it must always submit to real verification, and have values assigned to its symbols. PSYCHOLOGICAL PRINCIPLES. 173 70. Thus the human Intellect emerges from animal Intelligence, and develops a vast independent creation, having the whole Cosmos and Humanity for its mate- rial. Concurrently with this, the Moral Intelligence develops its system. Both Intellect and Conscience are products of the animal impulses and social impulses acting and reacting. While the Intellect is mainly occupied with the relations of the Cosmos and its His- tory, having the ultimate aim of making these subser- vient to practical needs, the Conscience or Moral In- telligence is mainly occupied with the relations of Hu- manity human needs and human actions having the ultimate aim of conforming our conduct to those rela- tions, harmonising our impulses with the impulses of others, thus aiding others and gratifying ourselves. The Intellect although under sympathetic conditions since it depends on others for its activity, and for the means by which the activity may be guided, and since, moreover, its results are achieved for all is not so directly sympathetic as the Conscience. Could we suppose a man born with his inherited aptitudes, left solitary on an island, before having had access to any of the stores of knowledge accumulated by the race, he might acquire a rudimentary knowledge of cosmical relations, although without Language, or any accessible store of the experience of others on which to proceed, this would necessarily be little above that of an animal. But of Moral Intelligence there would not be a trace : There cannot be moral relations apart from Society. 71. Hence two noticeable facts : the part played by Sentiment in Philosophy is of immense importance in so far as the problems involve elements of social rela- tions ; but is simply perturbing and obstructive in pro- 174 PROBLEMS OF LIFE AND MIND. blems of cosmical relations. We ought not to deny the admission of Sentiment, but we must definitely assign its sphere. A social theory which omitted it, would be as defective as a cosmical theory which admitted it. If Evangelical Geology or High Church Chemis- try would be absurd ; equally so would be an exclu- sively physical theory of Marriage, or of the filial and parental relation. 72. The Intellect and the Conscience are social functions ; and their special manifestations are rigor- ously determined by Social Statics i.e., the state of the Social Organism at the time being which they in their turn determine. The Language we think in, and the conceptions we employ, the attitude of our minds, and the means of investigation, are so- cial products determined by the activities of the Col- lective Life. The laws of intellectual progress are to be read in History, not in the individual experience. We breathe the social air : since what we think, greatly depends on what others have thought. The paradox of to-day becomes the commonplace of to-morrow. The truths which required many generations to discover and establish, are now declared to be innate. Even dis- covery has its law, and is only an individual product inasmuch as the individual voice articulates what has been more or less inarticulate in the general thought. The great thinker is the secretary of his age. If his quick-glancing mind outrun the swiftest of his con- temporaries, he will not be listened to : the prophet must find disciples. If he outrun the majority of his contemporaries, he will have but a small circle of influ- ence, for all originality is estrangement. Not recognising the social influence, men seldom PSYCHOLOGICAL PRINCIPLES. 175 appreciate the true point of view in discussions respect- ing ancient and modern Literature. It is undeniable that Sophocles, Plato, Aristotle, Hipparchus, and Galen were not less splendidly endowed than Shakspeare, Bacon, Newton, Comte, or Helmholtz their intellec- tual lineaments may have been as grandly drawn, but it is absurd to pretend that the products of the ancient and the products of the modern mind are of anything like equal value. 73. Some of our Impulses are simply organic activi- ties, others are Instincts. There is no Instinct to breathe, to digest, to secrete, &c., for there never was a time when an alternative action was possible with these organs under their appropriate stimuli the actions were necessarily determined in one way only. But food is selected by Instinct; the bird flies, and the mammal walks by Instinct : these actions are tentative, and guided by discerning Feeling. The sexual instinct is obviously an impulse guided by Discernment. Directly connected with the Nutritive Instinct are three egoistic Impulses, offensive and defensive, which may be characterised as the Aggressive Instincts. The animal must destroy, or it could not feed. A rival threatening to take some of this food rouses Anger, the emotion of a thwarted impulse. The thwarted sexual impulse calls out the same feeling. Derived from this will be in the higher imaginative animals the love of Domination : the desire to make others afraid of, or subservient to us. Where food is abundant, and accessible, there is little development of these tenden- cies ; as may be observed in the herbivora, who rarely fight unprompted by the sexual impulse. Tigers would be sociable were animal food as abundant and 176 PROBLEMS OF LIFE AND MIND. accessible as vegetable food. War is the outcome of this tendency. In Trade we see the war spirit ani- mated by the desire for Property. The so-called instinct of Self-preservation is a fiction. The only impulse at work there is the shrinking from Pain ; and this in the matured experience leads to the intelligent act of self-preservation. As the Aggressive Instinct springs from the Nutri- tive, so the Sexual Instinct springs from the Repro- ductive. It is the first of the sympathetic tendencies, the germ of Altruism. Love, which is the social motor, has this origin. Thus modified, the tendency to Domination becomes the love of Approbation : it is the sympathetic form of the egoistic impulse. The love of wife and children extends to relatives and friends, to the tribe, to the nation, to Humanity. How intimately the social and religious emotions are connected with this primary fact of the mutual dependence of two human beings, and how from it slowly emerge all the marvels of Art and Science, must be exhibited in detail. REASONED REALISM. 74. Having briefly indicated the Psychological Prin- ciples, I will now indicate what is their outcome with respect to the great metaphysical question touching an external reality. It will be argued at length in a separate Problem ; but as the publication of this Pro- blem is distant, and as its conclusions will everywhere be implied, I take this opportunity of clearly marking tny position. The doctrine of this work, then, may be called Reasoned Realism. It is distinguished from the PSYCHOLOGICAL PRINCIPLES. 177 Natural Eealism, the Hypothetic Realism, and the Symbolical or Transfigured Realism of modern thinkers, no less than from the unhesitating Realism of unre- flecting minds. It is a doctrine which endeavours to rectify the natural illusion of Reason when Reason attempts to rectify the supposed illusion of Sense. I call it Realism, because it affirms the reality of what is given in Feeling; and Reasoned Realism, because it justifies that affirmation through an investigation of the grounds and processes of Philosophy, when Philosophy explains the facts given in Feeling. 75. The reality of an external existence, a Not-self, is a fact of Feeling so indissolubly woven into Con- sciousness, that the very terms in which Idealism seeks to disprove it are themselves derived from it. Now this fact, because it is a fact of Feeling, and ultimate, can neither be got rid of, nor explained by inter- pretation of it into terms of some more general fact. Why then has Philosophy persisted in the attempt to explain it ? Simply because Philosophy, being in its very nature Explanation, persists in attempting to ex- plain even the inexplicable : dissatisfied with ultimates, it is prone to ask what is their ultimate ? This search for light behind the light is the natural illusion of Reason, the will-o'-wisp of Philosophy ; and this can only be rectified by showing what are the grounds and what the" limitations of Knowledge. 76. The facts of feeling are directly given. All the phenomena constituting the external reality to us are presented discontinuously; and it is the office of Philosophy so to connect them that their actual con- tinuity be discerned ; and we thus not only have the separate feelings, but also a feeling of the relations of VOL. T. M 178 PROBLEMS OF LIFE AND MIND. these feelings. The Logic of Feeling, which is primary, has to be supplemented by the Logic of Signs, which is derivative. Analysis attempts to display, in symbols, what has been implicit in sensation. But and this is the point too commonly overlooked all interpretation must finally be a reduction into terms of Feeling, all the symbols must signify sensations. Feeling is the starting-point and goal of investigation. All that we can know of the external is what we have felt or might feel. 77. This being the ground, what is the limit of Knowledge ? The limit is attained when we have at- tained what in Algebra is called the 'form of a function/ In Mathematics a 'function' is the quantity which varies when some other quantity varies. When observation of two phenomena discloses that the one say the den- sity of a gas varies with another say its pressure, the density is said to be a function of the pressure ; when vital activity is observed to be exalted or depressed with increase or decrease of respiration, the activity is said to be a function of the respiration. Such knowledge of a function is valuable, but it is ob- viously not final. What is still needed is the form of the function the manner in which the two quantities are combined. When this is reached the limit is reached. When the law of a series is found, nothing remains to be sought. When we know the how, it is idle to ask the why. The fact is what it is, and what its factors are : if we know the fact and the factors, to ask for more is to ask why 2x2 = 4. The gas presses against the sides of the containing vessel, because the gas is composed of movable molecules dashing about in all directions with various velocities, and the amount of PSYCHOLOGICAL PRINCIPLES. lV9 this pressure must of course increase in proportion to the diminution of the space in which these motions take effect, since on every inch of surface there will then be a proportionately greater dashing of molecules. Thus the smaller the vessel becomes, the greater must be the density of the gas contained in it, since the gas fills the vessel ; and the greater the density, the greater . will be the pressure excited by the gas. Now if it be true that the gas molecules in their movements repel each other inversely as the fifth power of the distance (or indeed if any other law of repulsion can be estab- lished), we shall then 'be in possession of the form of the function, and the final result of analysis will be reached. To go beyond this, and to ask why the molecules repel according to this law, is irrational, because travelling beyond the real limits and conditions. 78. Now it may seem a very bold thing to say, but I hope to justify the assertion, that with respect to the world-old debate on the relation of Object and Subject we have not only a knowledge of the function, but of the form of the function ; or to put it in more familiar language, we not only know that an external Not- self exists, know it with the same assurance that we know an internal Self to exist, but we also know the manner in which the two are combined in Feeling and Thought. Fully aware of the paradoxical aspect this statement must present to almost every reader, I only ask him to suspend his judgment on it until he has accompanied me through all the evidence which this work will offer. Having made my statement, I will here say no more, but call attention to the unsatisfactory nature of the position commonly held. The ordinary man believes 180 PROBLEMS OF LIFE AND MIND. that the objects he sees, touches, and tastes do verit- ably exist, and exist as they are seen, touched, tasted. They have the qualities he feels in them. The philo- sopher, dissatisfied with the facts directly given in Feeling, though he no more than the ordinary man doubts that these qualities are felt, endeavours to ex- plain why it is that they are so. To explain a fact is to interpret it by its factors, to analyse it into its con-, stituents ; which again means to interpret a feeling in terms of feeling. This need for an explanation is ex- clusively human. No animal explains : he feels, and his action is the direct consequence. But man desires to understand what he feels, in order that he may modify the course of events, by rearranging their separate factors. To do this he must take the complex whole to pieces, and see of what it is composed. The speculative intellect carries out in the remote regions of knowledge, what the practical intellect daily performs in the familiar regions of Practice : it takes the object to pieces. 79. Great and beneficent as the results of this ana- lytic tendency have been, there have also been attendant drawbacks. By cultivating this tendency to look away from the given reality, in search of its prior conditions or its presumed factors, men have learned to slight the plain indubitable facts of Feeling, in favour of the ob- scure and doubtful representations of these facts in Thought that is to say, replacing perceptions by con- ceptions, facts by theories and hypotheses, men have come to distrust the Logic of Feeling, even within its own domain, and to rely on the Logic of Signs, even when it contradicts that of Feeling. Accustomed to attach exclusive importance to symbols irrespective of PSYCHOLOGICAL PRINCIPLES. 181 the realities, they have forgotten that ideas can be valid only as representative of sensations, and symbols can be useful only when capable of interpretation. For what was the starting-point of every theory ? An observation. And what is the test of the theory ? A reduction of its inferences to sensations. The theory started to explain a fact ; the inferences were intended to re-present what would be presented in Feeling, were the inferred facts, facts perceived. Obviously, there- fore, every theory must be a failure which ends in denying, or ignoring, the original fact. Yet this as- suredly is the case with the current theories of Percep- tion, idealistic and realistic. The original fact given to all, is that of an external reality present in Feeling ; the fact that a Not-self exists, that objects affect us by their presence, and have qualities variously felt by us this, I say, may possibly be explained, interpreted in other terms of Feeling, and classed with other facts, but cannot be ignored, or denied, without violation of first principles. 80. Yet this is done by metaphysicians under various forms. What they have to explain is not the fact which is ultimate, but the factors of the fact, i.e., the in- direct conditions of this direct reality, the invisible constituents, objective and subjective, of this visible phenomenon. That is to say, to exhibit in analysis what was given in a synthesis ; to reach if possible the ' form of the function.' How have they proceeded on this quest 1 From of old they made the false step of proclaiming the natural illusion of Sense ; founded on a precipitate conclusion from practical mistakes, this notion of the Senses as sources of deception, led to the conclusion that Reason was the only ground of security. 182 PROBLEMS OF LIFE AND MIND. If Sense deceived us, Reason corrected the false reports. Reason henceforward became authoritative, final. This, which may in turn be called the natural illusion of Reason, can only be dispelled by a thorough investiga- tion of the genesis of Reason ; and since that genesis exhibits it in the light of a derivative from the primary facts of Feeling the virtual representation of what would be actual presentation we cannot hesitate to assign a lower validity to its symbolical constructions, than to the primary facts which those constructions render intelligible. It is surely obvious that no theory of Perception can have the certainty that belongs to the Perception itself no explanation of a conclusion can be valid which ignores the very facts concluded, shut up in the starting-point. 81. It was to explain the perception of an external reality that Philosophy started on its quest. The Ideal- ist schools find the explanation to be that there is really nothing to explain except the illusion that an external reality exists. The Realist schools, while ad- mitting that an external reality veritably exists, declare that it can never be known by us as it exists, but only under some form in which we clothe it : there is, there- fore, still a touch of the old illusion lingering in it, and our surest knowledge is after all phantasmal. 82. The Reasoned Realism of this work denies alto- gether the assumed distinction between noumenon and phenomenon except as a convenient artifice of classi- fication by which the unknowable otherness of relations is distinguished from the knoivdble relations: that is to say, noumena standing for things in their relations to other forms of Sentience (if there are such) than our own ; and phenomena standing for things in any con- PSYCHOLOGICAL PKINCIPLES. 183 ceivable relations to Sentience like our own. Getting rid of the Ding an sich, or noumenon, as a phantasm that has no existence for us, consequently cannot come within our perceptions, nor within any theory of per- ception, and is therefore altogether banished from the sphere of Knowledge, we are led through our psycholo- gical analysis back to the synthetic starting-point namely, that the external world exists, and among the modes of its existence is the one we perceive. Eation- ally interpreted, we may accept the ordinary belief that colour is a quality of the object seen, that heat is in the fire, roughness is in the rough surface, &c. ; and at the same time we may accept the philosopher's assertion, that all these qualities in objects are feelings in us. Psychogeny will show us that colour, heat, &c., are, from one point of view, both in the objects and in us ; from another point of view, they are in neither. 83. Let me explain. \\ r hen first men began to ana- lyse their perceptions, they were so greatly impressed by the importance of the subjective aspect, and the de- pendence of Feeling on the state of the sentient organ- ism, the same object producing such various sensations at different times, that they reversed their, primary and instinctive judgment, and instead of saying, "qua- lities belong to objects," they now said, " it is we who invest objects with the qualities of our feelings." From that time the subjective aspect has so predominated that Psychology has almost lost its hold of the objective world ; and in many treatises resembles an Astronomy which should record the laws of planetary movement, ignoring the existence of planets and perturbations ; or a Biology which should explain Life by processes of composition and decomposition, denying that there 184 PROBLEMS OP LIFE AND MIND. were any organisms in relation to a medium to mani- fest these. 84. Kant boldly carried out this reversal of the pri- mary judgment of Feeling. The external phenomena were to him only 'objects' in virtue of the Mental Forms imposed on the noumenon. I do not discuss the question here ; but only say that the doctrine of this work stands by the primary judgment of Feeling, and is a Eeasoned Realism because it does so. The external world must be at first simply a confused chaos, without shape or order, when reflected in a Sentience which has not acquired shaping reactions. But as the sentient Organism develops, the external Order emerges ; not because this Order is the creation of the Organism, stamped upon the chaos, but because this Order is assimilated by the Organism, selected, ac- cording to its shaping reactions, from the larger Order of the Eeal. The undifferentiated animal substance slowly develops into highly differentiated tissues and organs, through the action on it of the external agencies, which leave their traces in a modified structure and capability of reacting : the pulpy mass of the brain ac- quires, through manifold experiences, a structure more and more variously definite, with corresponding reac- tions ; and as Feeling becomes differentiated and de- fined, Qualities arise in the Felt. It is thus that the nebula of the external is condensed into objective phe- nomena, and the confused irradiation of Sensibility is grouped into feelings. 85. Is this figured Cosmos figured in Feeling through the adaptation of the sentient organism to the external Real, or is it simply a subjective construction the figuration of Sensibility which we illusively pro- PSYCHOLOGICAL PRINCIPLES. 185 ject outwards and receive back again in reflection? Do we see objects coloured because objects colourably affect the retina ? or do we see them coloured because the retina casts its tints upon them ? Do we acquire our modes of sentient reaction through modifications impressed by the actions of the external 1 or do we bring with us, and from another source, the Mental Forms in which the unshaped external takes shape ? These different statements of the same fundamental problem suggest somewhat different answers. Be- tween Realism and Idealism, I should say that the question must be rendered more definite by a preli- minary settlement as to whether we ask a question of Psychogeny, or a question of Psychology. If it is the genesis of our modes of sentient reaction, and their relation to the external, which we consider, then the answer will take the realistic form ; since Psychogeny, tracing the evolution of Sensibility in the organic world, must conclude that it is the External Order which determines the Internal Order, by determining the organic structure of which Sensibility is the pro- perty : the evolution of perceptions, instincts, volitions, conceptions, is through successive adaptations of the successively modified structure ; precisely as the evolu- tion of all the vital phenomena is through successive adaptations.*" But if the question be not one of gene- sis, if it assume the existence of the organised structure with its developed aptitudes, the answer will be a sort of compromise between the realistic and idealistic answers. Psychology accepting the developed Organ- ism, as one of the factors in the fact of Perception, estimates the influence of this co-operant, and concludes * This has been shc^vn in a masterly manner by Mr HERBERT SPENCER. 186 PROBLEMS OF LIFE AXD MIND. that since the Organism necessarily reacts according to its modes, it may be said to colour objects, although this mode of reaction is itself a mode originally due to the action of objects. It is Light which fashions the retina to luminous responses. Not that the external Eeal which stimulates the retina can be supposed to be itself luminous : it is only one factor of the luminous product. Nor can the retina, apart from stimulation, be luminous : it also is only one factor. But Light the Object is both factors : thus the object is necessarily object-subject; and subject is equally subject-object. I do not agree with those realists who conceive the thing represented in Perception, in the way mathematicians regard an algebraic function as represented by a curve object and subject forming a Dualism having something of a pre-established harmony but no real union. I would rather liken the Thing represented in Perception, to the weight of the atmo- sphere represented by the height of the mercury in the barometer; while the differences between weight and height, and between atmosphere and mercury, are wide, both rest on a common identity of pressure. The pressure of the atmosphere is the pressure exerted on the mercurial column, and the barometrical expression of this pressure is, in one sense, no more like the object expressed, than a feeling is like the vibrations it expresses ; yet, in another sense, the barometrical expression is what it expresses, and the feeling is what it expresses. 86. It seems to me a grave objection to Idealism that there is no possibility of separating Object from Subject, or Subject from Object, in Feeling, but only in Reflection ; and . Reflection is not primary, but PSYCHOLOGICAL PRINCIPLES. 187 derivative. Nay, even here it soon appears that the distinction is simply that of aspects. We declare the existence of a Real apart from Feeling, and of events linked together by other ties than those of our modes of conceiving them ; because if we assume such an existence it enables us to explain the phenomena which agree with, and the phenomena which contradict our previsions. Granting this assumption to see what are its consequences, we find that having through successive adaptations acquired an order in our feelings corre- sponding with the order in things, we can from it pre- dict what will be the order of events on a future occasion ; and this prediction is verified, not simply in respect of the events following the order we have pre- figured, but the order which will appear the same to others who have no such prefiguration of it, and can- not therefore be supposed to have introduced their sub- jective constructions into it. A chemist, suppose, has learned the order of events by which salts are produced. He can produce a salt where there is no salt. If his conception of the real order were a subjective construc- tion without objective correspondence, he could only see what he had foreseen, and the salt would inevitably appear to him. But on proceeding to realise his con- ception he sometimes stumbles on a contradiction : no salt is produced : he sees what he had not foreseen. Why 1 Because he had assumed that the order of real events would be that of his ideal scheme ; whereas in reality there has been some other order, some events not included in his construction, and he has to seek these out, reform his construction, and then proceed to verify it when thus reformed. 87. But while Idealism tries to get rid of the primary 188 PROBLEMS OF LIFE AXD MIND. fact that Not-self is the correlative of Self, and in no wise a product or projection of Self, but a given factor in Consciousness, having the same validity as Self, all the schemes of Eealism with which I am familiar err on the side of neglecting the one factor or the other. The ordinary man, undisturbed by philosophic specu- lation, accepts a Dualism of Mind and Matter, and imagines the External Order to be something wholly independent of the Internal Order, imagines Things to exist precisely as they are felt and thought, even when there is no sentient subject to feel and think them. But the philosophic realist also more or less avowedly accepts a Dualism ; since, although he may reject the crude distinction of Mind and Matter, he keeps to the wide distinction of Motion and Feeling, with its correlative distinction of Object and Subject, as two parallel existences which can never approach each other, much less unite. The Subject is conceived under the likeness of a kaleidoscope; every external force will disturb its arrangement of colours, and the rearrange- ment will accurately represent the amount and direction of the external force, but will have no other similarity or point of community with it. In this view our per- ceptions are symbols of the external reals, but have no more likeness to the reals, no more community of kind, than a numerical figure has to the figures of the num- bered objects. 88. This view has advocates so eminent that I must decline the discussion of it until the fitting occasion arrives for treating it exhaustively. Here, where I am avowedly indicating my own position, and not en- deavouring to prove it, the statement must suffice that I regard the Subject in no such alienation from the PSYCHOLOGICAL PRINCIPLES. 189 Object ; and regard Perception as the assimilation of the Object by the Subject, in the same way that Nutrition is the assimilation of the Medium by the Organism. Out of the general web of Existence certain threads may be detached and rewoven into a special group the Subject and this sentient group will in so far be different from the larger group the Object ; but whatever different arrangement the threads may take on, they are always threads of the original web, they are not different threads. The elements of the sentient Organism are the elements detached from the larger group ; the motions of the sentient Organism are the motions of these elements. We do not suppose that when what is called the physical motions of molecules are grouped into what is called the chemical actions, and surprisingly novel phenomena emerge, there has been anything essentially superadded to the primitive molecules and their forces. Nor do biologists now suppose that when physical and chemical actions are specially grouped and vital phenomena emerge, any- thing essential has been superadded to the primitive threads of objective existence. The chemical pheno- menon is new, the vital phenomenon is new ; but the novelty is one of special grouping of the old material and the old energy. In like manner, when the psychi- cal phenomenon emerges from the vital, and the social phenomenon from the psychical, there is a regrouping, not the introduction of new material, above all not a casting away of the old. The Subject is inseparable from the Object, in any real sense ; is only separable ideally. As the flower which comes into existence through the action of the sun, incorporates the energy of the sun, and grows by what it takes from the sun ; 190 PROBLEMS OF LIFE AND MIND. so the sentient Organism incorporates the energy of the External, and reproduces all that produced it. 89. To those who have accepted the view of Life being an emergent, not due to a conflict between the external and internal, but to their co-operation, the ex- tension of the view to Perception lies near at hand. To those who have accepted the view of Mind drawing material from the Social Medium, and who admit that the human being lives, feels, and thinks by the con- tinual assimilation of such material, the following question may be submitted : When the mind per- ceives any social fact, and apprehends its social signi- ficance, is the fact real, or not ? Let the fact be a religious service performed in a cathedral, or a political service performed in a legislative assembly. The sen- sible phenomena are of course perceived through sen- sible channels, and are interpreted with more or less accuracy according to the registered experiences of the observer; precisely as any cosmical fact will be per- ceived and interpreted. In both cases there is a synthesis of sensible impressions, feelings reproducing former feelings ; and if these are interpreted, it is by an ideal construction which is determined by previous constructions. By an animal, or a stranger, the sensible phenomena which the religious service presents would be very differently interpreted ; but the sensible phe- nomena presented in any cosmical process would also be differently interpreted by them ; since interpretation means mental assimilation, the significance of the phe- nomena must depend upon the pre-perceptions and pre- conceptions which they arouse. Nevertheless, wide as the gap may be between the interpretation of the savage and the interpretation of the citizen, the reality of the religious service is unaffected : it is to each PSYCHOLOGICAL PRINCIPLES. 191 what they feel it to be, and it is to each what they think it to be : in other words, they have been sensibly impressed by certain reals, and have interpreted these impressions by means of certain symbols. From these subjective differences it has been concluded that there is an objective existence independent of all, and unlike each ; I hold, on the contrary, that the objective exist- ence is to each what it is felt to be. We have already ( 25) briefly indicated what must hereafter be exhibited in detail, that whatever is felt is necessarily real, since Reality and Feeling are correla- tive. Feeling only arises in the sensible excitation of the Organism by something acting on it, whereas what- ever is thought, conceived, is necessarily symbolical, since conceptions are not perceptions but symbols : they are not the sensations themselves in a synthesis, but general signs indicating such synthesis; as algebraic letters are not the numbers and magnitudes themselves, but symbols of their relations. This which is obvious enough in the case of general conceptions Life, Cause, Nation, Virtue, &c. is perhaps less obvious yet equally demonstrable in the case of less general conceptions Flower, Horse, River, &c., which are markedly distinguishable from the perceptions of a Flower, a Horse, or a River, which are always syntheses of feelings, and are real because both the elements (the sensations) and the synthesis are the actual and direct products of the external and internal factors ; whereas the conceptions formed out of these perceptions, al- though they have only validity in so far as they ac- curately represent real syntheses, are in themselves indirect products, mere symbols. The conception of Virtue, for example, is altogether unlike the concrete actions which it signifies : unlike in its elements, unlike 192 PROBLEMS OF LIFE AND MIND. in its synthesis. It is not a real, i.e., an external agent capable of exciting a corresponding perception, but an abstraction, a symbol expressing the many feelings which the concrete actions are capable of producing ; and is comparable to the algebraic symbols, which, though utterly unlike the quantities they represent, do nevertheless stand for those quantities, and are operated on with equal facility. In some of our con- ceptions and in some of our pictorial symbols, there is a sensible suggestion of likeness between the sign and the thing signified : in the conception of Flower, or in the symbol of a Lion representing the kingly attri- butes of a Chief, there can be traced some perceptive suggestion. But in other conceptions and symbols no resemblance, no perceptive suggestion, is traceable ; if there were originally a suggestion it has long since faded from the view ; and in all cases the symbol is constructed out of different elements in different ways, so that it is really unlike what it stands for, is different from what it signifies. This contrast between Conception and Perception, between the Symbolical and the Real, which is a funda- mental point in Psychology, renders intelligible what was said (63) respecting the Ideal World absorbing the universe in a Transfiguration ; and at the same time marks my dissent from the theory of Transfigured Eealism, upheld by Helmholtz and Spencer ; for that theory professes to be a theory of Perception, and de- clares Perception to be symbolical ; whereas, according to the principles here expounded, Perception being the resultant of the two factors, internal and external, the conclusion deduced is that the object thus felt exists precisely as it is felt ; existing for us only in Feeling, PSYCHOLOGICAL PRINCIPLES. 193 its reality is what we feel. The great thinkers whom I am here opposing fully admit the premises of this conclusion ; with this reservation : they hold that since the internal factor is a necessary co-operant, it must alter by its co-operation the character of the external, and the product of the two will be unlike either. Having for many years maintained this position I am not insensible to its significance. I shall en- deavour, however, to reconcile the differences, and to show that Perception because it is a resultant, not a symbol, does not alter the Eeal; on the contrary, an object only is to us what we feel it to be it exists in that relation. This does not, of course, ex- clude the possibility of the external factor having an- other existence in relation to other factors ; all that can legitimately be affirmed is that this particular thing in this particular relation is what it is in this relation, i.e., what it is felt to be. What we mean by saying that a thing is real, simply amounts to this : it will always in such or such relations have such or such modes of existence, and in all similar relations similar modes. This conclusion is as absolute as that two multiplied by two will always be four, and that two multiplied by three will always be six. This question of the reality of an external world will have to be treated at length in a separate problem ; I here indicate simply the principal lines of the conclu- sion to which I have been led. Neither crude Kealism nor any form of Idealism satisfies all the conditions of the problem. The world conceived by us, the world in Thought, is demonstrably not a picture of the Existence lying outside of us and unrelated to us : it is a Transfiguration effected by the ideal construc- VOL. i. v 194 PROBLEMS OP LIFE AND MIND. tion of real presentations in Feeling. Were this External, such as we conceive it, existing objectively, Science would not have been in travail for centuries : the objective existence would have been plain to Sense, needing no Science to make its order plain. On the other hand, were this External a purely subjective creation, the projection of an ideal order, it would have needed no study to understand it, for it would have spontaneously unfolded its mysteries before our gaze. The necessity of long-continued observation and reason- ing, the necessity of analytical operations to make clear the sequences of observed events, the changes in our knowledge and the slow evolution of our conception of the External Order, disprove both Realism and Idealism. The psychological facts that Existence is directly perceived and indirectly conceived, that what is felt is real, and what is thought is symbolical of what is felt, suffice to justify the theory of Reasoned Realism. 90. No little confusion arises from an almost inevi- table ambiguity. We apply the term Object to the Not-self. This Not-self may be either the objective aspect of the world felt and thought, i.e., of the Exter- nal in actual and virtual relation to Sentience ; or the universe of existence, conceived in its totality, includ- ing .that smaller section of it which is grouped by a Subject. -When we say that there is identity of Object and Subject, the meaning ought to be that in respect of Existence in its relation to Consciousness, Object and Subject may abstractedly be considered under different aspects, but they are one and the same phenomenon. Nichts 1st drinnen, Nichts 1st draussen, Denn was innen, das ist aussen, So ergreifet ohne Saumniss, Heilig offentlich Geheimniss. PSYCHOLOGICAL PRINCIPLES. 195 But this can no longer be said of the Universe con- sidered as the totality of Existence, under which aspect the Object is not the other side of the Subject, but the larger circle which includes it. This is, how- ever, a topic which must be discussed hereafter. Eeasoned Realism not only justifies the primary judgment of Feeling, but gets rid of the notion that because Knowledge is necessarily relative therefore it cannot be real. I hope to show that instead of invok- ing an Unknowable as the dark Dynamis to which all researches point instead of concluding that knowledge of things as they are is impossible, and that our most certain results are only symbols of an unknown reality the conclusion will be, that although the region of the Unknowable may be infinite, within the region of the Knowable we do know things as they are, know them absolutely, comprehensively, in any rational sense to which the term Knowledge ever was applied. This chapter may be fitly closed with the words of Auguste Comte : " Le but le plus difficile et le plus important de notre existence intellectuelle consiste a transformer le cerveau humain en un miroir exact de 1'ordre exte'rieur. C'est seulement ainsi qu'elle peut devenir la source directe de notre unite* totale, en liant la vie affective et la vie active a leur commune destina- tion. La possibility d'une telle transformation repose sur la part ne'cessaire de 1'ordre exterieur dans notre propre exercise mental, dont il fournit toujours les premiers mate'riaux. Outre cette alimentation elemen- taire, il y influe aussi comme stimulant, et meme comme re'gulateur, ainsi qu'envers toutes les autres fonctions vitales, ve*ge"tatives ou animales." * * Politique Positive, ii. 382. PROBLEM I. THE LIMITATIONS OF KNOWLEDGE. " It is the very essence of Philosophy to rest upon the foundation of common per- ceptions, and by reasoning from these to account for phenomena." Prof. CHALLIS : Philosophical Magazine, xxvi. 285. " Alles ist in der Empfindung und, wenn man will, Alles was im geistigen Bewusst- sein und in der Vernunft hervortritt, hat seine Quelle und Ursprung in denselben ; denn Quelle und Ursprung heisst nichts anders als die Erste unmittelbarste Weise in der etwas erscheint." HEGEL : EncyUoptedie, 400. THE LIMITATIONS OF KNOWLEDGE. CHAPTER I. THE PRINCIPLE OF EELATIVITY. 1. HODGE, who has never left his native village, knows little of this wondrous planet, and less of the wondrous universe of planets ; yet something of it he does know, and this knowledge is real, if narrow, nor would it be made more real by a wider horizon. The cattle grazing in the meadow, the pigs foraging through the quiet street, the apple-blossoms brightening the orchard, the rooks cawing among the squire's elms, the children at his hearth, the neighbours in the parlour of the King's Arms, the parson, the doctor, the squire these, and the other objects of his world are realities, not phan- tasms ; nor are Hodge's affections and duties illusions. His world is bounded by a not very distant horizon. Visitors passing through his village now and then bring news from the larger towns. Newspapers carry to him murmurs of the far-off roar of things. These tell him that his world is not the whole world ; and the death of those dear to him tell dimly of a world of mystery 200 PROBLEMS OF LIFE AND MIND. surrounding all he knows. But these intimations of a larger life do but intensify the reality of his village life. Hodge has a brother, who early left home, travelled far, learned something of other villages, cities, con- tinents; passed into strange lands where alien faces and unfamiliar voices obtruded on his notice. His con- ^ception of the world widened. The details of external nature acquired new significance for him. Things passed from the commonplace into the grandiose. The sun no longer pleasantly warmed, it scorched; the wind became a whirlwind ; the rain a deluge ; woods were forests, hills mountains, cats tigers. In the moral world the changes were equally great. That which in one place was duty, in another place was sin, in a third was indifferent ; what inspired honour here was held as infamy elsewhere. Yet under all these varieties there came to him no deepened sense of reality ; more rela- tions of things were learned, but Life still remained at once the old revelation and the old mystery. Hodge is the common man; his brother a philo- sopher. The parochial conception of the world formed from the experience of the one, is different from the pro- vincial conception of the other ; but neither conception embraces the whole Universe, though both conceptions are real, and relatively true. 2. The principle of the Relativity of Knowledge, which is indicated in these sentences, is sometimes resisted on the ground of its leading to universal scep- ticism. The fact, however, is otherwise, and may be shown to be so by the teachings of Psychology and the examples of History. The certainty of knowledge is not affected by its circumscription. The principle of THE LIMITATIONS OF KNOWLEDGE. 201 Kelativity furnishes a Criterium which is coextensive with the domain of intelligence. The opposing prin- ciple is productive of scepticism because it has no Cri- terium. It remains fluctuating, because its data are personal, and cannot be communicated. Those who, affecting to despise the certainty attainable through Science, because it can never transcend the relative sphere, yearn for a knowledge which is not relative, cheat themselves with phrases ; and were it not so, we might still fall back on the position that relative know- ledge is all we need. The aim of Science is prevision the guidance and regulation of action. Our ancestors guided their course by the stars, without knowing much about the stars : the ascertainment of a few rela- tive positions sufficed. Their successors constructed an elaborate science of Astronomy without inquiring into the nature of gravity, contented with the ascertainment of its law. And so throughout. What is positive may be absolutely certain and available, although it is but a small section of the circle swept by Speculation. 3. The world is to each man as it affects him ; to each a different world. Fifty spectators see fifty dif- ferent rainbows in the sky, and all believe they see the same one. Nor is this unanimity delusive ; for " the same" here means the similarity in their states of con- sciousness. Whether we affirm the objective existence of something distinct from the affection of conscious- ness, or affirm that this object is simply a reflection from consciousness, in either case we declare that the objective world is to each man the sum of his visionary experience an existence bounded on all sides by what he feels and thinks a form shaped by the reactions of his organism. The world is the sum total of pheno- 202 PROBLEMS OF LIFE AND MIND. mena, and phenomena are affections of consciousness with external signs. 4. We may for the present set aside the questions whether there is one Existence (Matter), and another Existence in every way contrasted with it (Mind) or only one Existence, Matter or Mind; enough if we recognise the fact that among phenomena there are two classes broadly distinguishable the material and the psychical. These classes require corresponding names, even should we finally regard them as only different aspects of a common reality, and with Fechner regard material and psychical as the convex and concave of the same curve.* At the outset, therefore, we declare the limitations of Research to be fixed by the natural limits of Conscious- ness. A truism, no doubt, but not to be despised. We can determine what problems are inaccessible (as dis- tinguished from those which are simply unapproached) by ascertaining the conditions under which objects do affect, or could affect us ; and we can determine what elements in every problem are unapproachable, by ascer- taining if they lie outside the sphere of Experience. Nor would this position be disputed, in its first clause at least, even by those who believe in the possibility of a knowledge of things transcending Experience ; for they claim their d priori organ as a " fact of conscious- ness ; " and they affirm that because it is a priori its verdicts have a higher validity than those of inductive reasoning. In presence of such a school we must be careful not to affix limits to the reach of Investigation, which this school would reject. It would be absurd to exclude an organ so important as that named In- * FECHNER : Zendavesta, 1851, ii 340. THE LIMITATIONS OF KNOWLEDGE. 203 tellectual Intuition (or its equivalent fund of Innate Ideas, Fundamental Truths, d priori Forms of Thought) unless we could show either that this faculty does not exist, or, granting its existence, that its products must be so removed from all Verification as to be of no avail in Research. The former alternative, that no such faculty exists cannot be demonstrated ; since its assumed range of operation lies beyond the sphere of Demonstration; the latter alternative, that it lies beyond the sphere of Verification, is implied in the very state- ment of its pretensions. Philosophy, therefore, is not called upon to take any account of it, since for all the purposes of Research it is non-existent.* It is a mu- sician playing on a violin without strings, in the halls of a castle in the air. Fancy may endow this musician with superhuman skill, since Fancy has created him ; but the melodies are too subtle for human ears. 5. Rejecting, as I think we must, the notion of a possible source of Knowledge transcending Experience, we may admit that the notion has had some justifi- cation in the great imperfection of the psychological analysis put forward by the Sensational School. Strik- ing as have been the merits of that school, which explain its survival in the face of violent opposition and virulent criticism, and its gradual extension over the convictions even of opponents, these merits have not sufficed to displace altogether the doctrine of its opponents ; and very eminent thinkers still reject with scorn the conception of Knowledge being limited by Experience. This implies one of two things : either * HEGEL sarcastically says of this Intellectual Intuition : " Es ist die bequemste Hanier die Erkenntniss darauf zu setzen auf das was einem einfallt." Gesch. d. Phil., iii. 655. 204 PROBLEMS OF LIFE AND MIND. the doctrine itself is imperfect, or there is a radical im- perfection in. the statement of its principles and canons. I think both causes operate in keeping up the funda- mental discordance between the empirical and meteni- pirical schools. Let us first glance at the difficulties which beset not only the investigation but the exposi- tion of metaphysical questions, difficulties not found in science. 6. Suppose we have to ascertain the changes in Sensibility produced by some modification of a nerve- centre, or the introduction of some poison into the blood. Complex as the question is (how complex only those can appreciate who have made the experiment) it is at any rate free from doubts overhanging the very instruments we employ, and the laws by which the effects are measured. If in physical research we use a thermo- meter, or a thermo-electric pile, we have no need to pause and investigate the theory of the instrument, or to prove that its indications are quantitatively exact. We accept from the chemist the reagents we employ, and the ascertained laws of their properties. We never need argue respecting the accuracy of chronometer or hygrometer. All the primary physical facts are ready to hand, and have not now first to be established. Quite otherwise is it with Metaphysics. There every problem, besides its own obscurities, is overshadowed by the uncertainties hovering round its data. We cannot, for instance, accept Force as the cause of motion unless Cause and Motion have already been clearly defined ; and they are as obscure as the Force they are employed to render intelligible. We cannot stir a step in the exposition of the relation of Object and Subject without presupposing to be already settled fundamental THE LIMITATIONS OP KNOWLEDGE. 205 points of Psychology which are still under discussion. No explanation can be given of Matter which does not involve a conception of Force. Thus the inter-con- nections which are potent aids in physical inquiry are so many obstacles in metaphysical research. 7. Over and above these difficulties there is the special difficulty arising from the misleading influence of language. The sciences have each their technical terms, terms which, however arbitrary, are exact, terms which mean always the same thing, and not various things. Exaggerated as Condillac's notion was of Science being simply une langue bienfaite* a notion which reappears in the writings of those who hold that Mathematics is founded solely on its definitions (as if the objective relations thus defined were not real) there is an important truth in it; and no one can doubt that the superior exactness of Mathematics would vanish if the language in which its operations are expressed were tainted with the laxity so common in Metaphysics. No equations could be successfully treated if 5 were sometimes the symbol of 4 + 1, sometimes of 4 + 3, and sometimes 2 + 1. Yet such variation in the values is trifling compared with the variation in many metaphysical terms. Probably no two men mean precisely the same thing by the word Sensation, or Thought, or Cause, or Force. If these terms agree pretty well in their denotations they differ greatly in their connotations. Thus the proposition that thought is a transformed sensation, may appear preposterous, or indisputable, according to the meaning assigned to the terms. "We often hear a dispute dis- missed as " a dispute about terms." In Metaphysics, * CONDILLAC : Langue des Calculs, p. 7. 206 PROBLEMS OF LIFE AND MIIO). a dispute about terms is frequently the whole of the question : that once settled, Logic takes its course, and all differences disappear. I have already compared a metaphysician to the algebraist who does not assign arithmetical values to his symbols ; and it is obvious that the chief difficulty in Metaphysics, as in Algebra, is finding the value of the unknown quantity which will satisfy the equation. 8. The great dispute respecting the origin of know- ledge is a very striking example of this laxity in the use of terms ; and as the question is fundamental we must pause here to consider it with some attention. Each school has seized one aspect of the truth ; and a reconciliation may be effected, if we can point out the common ground of agreement, and their points of divergence. In attempting such a reconciliation I am not unaware of the position which a mediator between contending schools must necessarily seem to occupy; mediation always carries with it an air of superiority which is resented by both the antagonists ; nor will any disclaimer of such an assumption allay the irrita- tion. On the other hand, the first lesson in controversy is to unlearn our native tendency to treat our adver- saries as fools. If we learn this lesson, and try to seize the aspect of the truth which presents itself to their minds, we may find that this aspect which represents their experience also represents our own, and that the points of difference are reducible to differences in the data, leading to errors of interpretation. CHAPTER II. THE SENSATIONAL AND A PRIORI HYPOTHESES. 9. THE school of Locke maintains that "there is nothing in the Intellect which was not previously in Sense; all the differences between our thoughts and our sensations are due not to differences of origin, but to differences of combination." The rival school of Leibnitz says : " Besides the materials furnished by Sense there must be taken into account the forms fur- nished by the Intellect." So far the two schools are but little opposed. The point of separation is in the assumption of a special source of knowledge in the Intellectus ipse an entity, or faculty, which has no community with Sense, and which not only furnishes Sense with forms, but also furnishes material, namely, certain Innate Ideas, or Fundamental Truths, which relate to existences beyond the range of Sense. Instead of simplifying the question by thus stating their common ground, and their point of separation, the two schools have been fighting on the supposition that the question was, "Is there anything in the In- tellect which cannot be traced to Sense 1 " Such a question could not be answered unless a distinct under- standing of its terms was arrived at. This was not 208 PROBLEMS OF LIFE AND MIND. done. The answers were consequently acceptable, or absurd, according to the meanings each school assigned to the terms. 10. The sensational hypothesis is acceptable if by Sense we understand Sensibility and its laws of oper- ation. This, indeed, which includes all the Biostati- cal and Biodynamical conditions, external and internal, is an extension of the term, and obliterates the very distinction insisted on by the other school ; but since it includes all psychical phenomena under the rubric of Sensibility, it enables psychological analysis to be con- sistent and exhaustive. Although such was obviously the dim meaning of the sensational school, one must admit that their language very imperfectly expressed it, and to some extent justified their adversaries in supposing them to mean by Sense simply the Five Senses ; and thus interpreted, the reduction of all know- ledge to a sensuous origin is absurd. 11. The hypothesis of the a priori school is accep* table if by Intellect be meant the process by which many different sensations are grouped together, thus forming products unlike any of the several components ; and since this process of grouping may be extended from the elements to the groups, the products will after successive evolutions be so far removed from all resemblance to the original sensations as to appear due to a different source. This is only another and a better way of expressing the sensational doctrine. It demarcates the process of grouping from the elements grouped ; the operation from the symbols : a conve- nient demarcation, but liable to mislead the unwary into the belief that the separation is real, and that Intellect is a special faculty having no community with THE LIMITATIONS OP KNOWLEDGE. 209 Sensibility and its laws. Once detached from Sensi- bility, it is easily imagined to be capable of operating on symbols that have no sensible values : transcending the range of Sensibility, it can deal with transcenden- tals, as Sense deals with sensibles. The error of both schools will be more fully exemplified when, in a future problem, we come to examine the relations of Feeling and Thought, and see reason to conclude that Sense and Intellect so thor- oughly interpenetrate each other that it is no less im- possible to conceive Sensation which does not embody the logical processes supposed to be peculiar to Thought, than to conceive Thought which does not embody the neural processes specially named Feeling. Meanwhile let us remark that both schools fall into the error of confounding a question of Psychogeny with a question of Psychology; an error similar to that frequently occurring in Biology, where questions of Anatomy are confounded with questions of Morphology. Thus the point at issue is, what is the genesis of mental pro- ducts, their origin and evolution ? Instead of re- tracing this genesis by analysis, the debaters fix their attention on the full-statured mind or at any rate on some stage far removed from the embryonic and the constituent forms there discovered are accepted as initial phases : the results which have been evolved through successive experiences are accepted as the primary con- ditions of all Experience : the inductions are made to precede the particulars from which they were generalised. 12. Before entering on an examination of this ques- tion it may be well to state here briefly the leading conclusions which will guide us throughout our criti- cism of the two schools. The main question must VOL. i. o 210 PROBLEMS OF LIFE AND MIND. remain nebulous so long as we are without a precise definition of Experience. The term is very variously and very laxly used. I have defined it " the Regis- tration of Feeling/' And what is Feeling \ It is the reaction of the sentient Organism under stimulus. Observe, it is not the reaction of an organ, but of the Organism a most important distinction, and rarely recognised. This reaction is a resultant of two factors one factor being the Organism and the other being the Stimulus. We are not to accept every response of an organ as a feeling ; nor every feeling as an expe- rience. The secretion of a gland is a response physiolo- gically similar to the response of the eye or ear ; but it is not a feeling, although entering as an element into the mass of Systemic Sensation. Nor will the response of a sensory organ, even when a feeling (through its combination with other sentient responses), be an expe- rience, unless it be registered in a modification of struc- ture, and thus be revivable ; because a statical condi- tion is requisite for a dynamical manifestation. Rigor- ously speaking, of course there is no body that can be acted on without being modified : every sunbeam that beats against the wall alters the structure of that wall ; every breath of air that cools the brow alters the state of the organism. But such minute alterations are in- appreciable for the most part by any means in our possession, and are not here taken into account, because being annulled by subsequent alterations, they do not become registered in the structure. We see many sights, read many books, hear many wise remarks, but although each of these has insensibly affected us, changed our mental structure, so that " we are a part of all that we have met," yet the registered result, the residuum has THE LIMITATIONS OF KNOWLEDGE. 211 perhaps been very small. While therefore no excita- tion of Feeling is really without some corresponding modification of Structure, it is only the excitations which produce permanent modifications that can be included under Experience. A feeling passed away, and inca- pable of revival, would never be called an experience by any strict writer. But the feelings registered are psy- cho-statical elements, so that henceforward when the Organism is stimulated it must react along these lines, and the product will be a feeling more or less re- sembling the feeling formerly excited. The two biolo- gical principles that an Organism is evolved through successive modifications, each of which is a reaction on stimulus and that the dynamical effect is necessarily determined by its statical conditions, the function by the organ assure us that what the Organism is at any stage determines what will be the kind of sentient reactions it is capable of. Such being our view of Experience, the conclusion lies near at hand that every Organism must bring with it, involved in its structure, the statical conditions of those dynamical results traceable in all Perception, Judgment, Instinct, &c. In other words, the Laws of Thought, or more accurately the Mental Forms, are connate, and so far d priori. But they are as much part and parcel of Experience as any individual percep- tion, judgment, or acquired ability can be. All that can be said to difference them is that, for the most part, they are parts of the Experience of ancestors the feel- ings registered in modifications of structure which have been transmitted from parent to child, so that " All experience past became Consolidate in mind and frame." 212 PROBLEMS OF LIFE AND MIND. How much of any one mental manifestation is due to ancestral feelings registered in the modified structure inherited, and how much is due to the individual feel- ings and their modifications acquired through the direct relation of the Organism to its stimuli, cannot accu- rately be determined. It is like the wealth which a merchant acquires through his own efforts, by employing the accumulated results of the efforts of previous gene- rations. But when the argument turns solely on the empirical or metempirical origin of knowledge there is no need to determine this ; if we can show that all our knowledge arises from, and is limited to, the reactions of the Organism under stimulus, the question reduces itself to the point whether over and above the Organ- ism known as a complex of physical, chemical, and vital conditions, there is also a Spiritual Organism interfused through this, and bringing spiritual properties to co- operate with vital properties. The vital Organism we believe to have been evolved through a succession of modifications due to its adaptations to the external Medium ; consequently, we believe all its functions or manifestations to have been evolved through Experi- ence. If, however, the spiritualist hypothesis be ac- cepted, all this argument founded on Evolution comes to naught; or it will come to naught if, instead of rely- ing on the spiritualist hypothesis, we accept the creative hypothesis, and declare that the Organism was created from the first that which we see it now, equipped with all its aptitudes and modes of reacting. It is one of these two hypotheses which underlies the argument of the d priori school. Nor can they be directly refuted. Indirectly, however, they may be discredited by show- ing that while they are wholly without positive evi- THE LIMITATIONS OF KNOWLEDGE. 213 dence, they are imagined only to explain the existence of those very aptitudes, connate tendencies, Laws of Thought, &c., which can be explained without such imaginary data, namely, as the necessary consequences of Experience. 13. Descending from these preliminaries, we see that the true question Psychology has to determine con- cerning the origin of knowledge is whether over and above the recognised avenues of Sensibility there are other avenues, in no one respect allied to them, through which Consciousness may be affected, and thus revela- tions reach the mind which, having no sensible origin, are not amenable to the canons of sensible Experience. But the dispute seems to turn on the very different question, whether the material furnished by Sense con- stitutes the whole product of Mind. The battle has been bloodless and endless, simply because the adver- saries have never actually met on a common ground. The empirical proclamation : Nihil in intellects nisi prius in sensu, was answered by the counterblast : Nisi ipse intellectus. But this was no assault on the em- pirical position, simply because the assertion that the Intellect existed, left wholly untouched the question as to hoiv that Intellect could be reached, and on what material it could operate. Both schools rested on the traditional assumption of the existence of a Mind endowed with certain Faculties. This Mind was supposed to be called into activity, and made to exercise its Faculties of Perception, Imagina- tion, Memory, Attention, Eeasoning, &c., by the influ- ence of external objects (according to one school) by the influence of external objects and native forms (ac- cording to the other). Now, it was obviously no answer 214 PROBLEMS OF LIFE AND MIND. to the sensationalists to proclaim what they never de- nied the existence of Mind. What was required was to show that this Mind is furnished with conceptions not in any way reducible to sensible experiences or com- binations of such experiences; to show, in fact, that there were innate ideas and truths, whose origin tran- scended Experience. On this point the argumentation of Locke is so triumphant that the doctrine of innate ideas has long been given up or rather has become transformed into a doctrine, which while seeming to occupy the old position does in truth relinquish it, but brings into prominence a truth never sufficiently al- lowed for by the school of Locke I mean the part played by the Organism and its inherited modes of reaction. 14. The psychologist finds among the phenomena classed under Alind two very distinct groups : perceptions and conceptions, images of concrete objects, and ab- stract symbols from which all trace of an image has escaped. He calls the one the products of Sense, and the other the products of Intellect. Not understanding their genesis, and impressed by their disparity, unable to detect any common measure between them, and persuaded that very many of our most important ideas cannot be analysed into mere affections of Sense, the d priori philosopher takes his stand on this evidence of the speciality of Intellect, and impatiently rejects the empirical hypothesis. It is clear that out of mere sensations as affections of the organism we cannot get negative conceptions and abstract notions. What is the sensible representative of our idea of Mind ? What is that of Life ? Granting these, and all other abstractions, to have originally had sensible concretes, THE'' LIMITATIONS OF KNOWLEDGE. 215 it is still indisputable that these objects of Thought never could have been objects of Sense. Whence are they derived ? If Sensation be restricted to the passive affections of Sense from which the co-operation of the logical processes is excluded, there is a radical defect in the sensational hypothesis. But the d priori hypothesis only cloaks this defect by a phrase ; it does not explain the phenomena. When Kant says that in order to render any sensible phenomenon intelligible, the Under- standing must add the notion of Substance, a notion which cannot be given through Sense, the statement really amounts to this : before a phenomenon can be raised into the logical sphere it must submit to logical conditions before the sensible can become intelligible it must assume intelligible characters. No one would dispute the position. No one would deny that there are logical processes which may be called Laws of Thought, the operation of which is as indispensable in the formation of judgments, as the laws of Geometry in the construction of figures. The question of vital importance is : What are these Laws, and whence their origin ? Kant declared that they were antecedent to all Experience, and made Experience possible ; he would not allow them to be innate ideas, but he re- frained from specifying what they were, except that they were native elements of Mind.""" The modern * His language is so confused and contradictory that by turns he is seen espousing the sensational and ct priori hypotheses. Emphatically declaring against innate ideas, he is yet frequently found employing ct priori concepts ; on the one hand declaring that we have only connate aptitudes, on the other that we have concepts antecedent to all Experience. HERBART'S criticism on KANT'S distinction between the Faculty of Kepre- sentation and its products, is unanswerable. HERB ART peremptorily rejects the notion of a Faculty which fashions sensations as a potter fashions clay. The Faculty and its Product are one thing, not two things. "We have 216 PROBLEMS OP LIFE AND MIND. biological school of psychologists fully admitting the operation of logical processes, and the wide differences between such processes and passive affections of Sense, endeavours to trace the genesis of these, their organic evolution, and their identity throughout psychical phenomena, from the simplest perception up to the most complex conception. It admits that the Mind, considered psychostatically, in the developed state, has certain endowments, or modes of operation, which de- termine the forms and products of its thinking ; and these are general laws which determine d priori, so to speak, even particular opinions, as general laws of Mo- tion determine particular motions. It further admits that these endowments, these Laws of Thought, and the conceptions which are their products when com- bined with sensible experiences, are assuredly not reducible to any individual experience, but to the evolved Experience of the race. 15. These large admissions, rightly interpreted, give no support to the d priori school In interpreting them it is necessary to guard against the illusion inci- dent to Abstraction, and the illusion incident to Meta- phor. The Mind is commonly spoken of in oblivion of the fact that it is an abstract term expressing the sum of mental phenomena (with, or without, an unex- plored remainder, according to the point of view) ; as an abstraction it comes to be regarded in the light of an entity, or separate source of the phenomena which constitute it. A thought, which as a product is simply an embodied process, comes to be regarded in the light no Sensibility (although we have sense organs) before the sensible feel- ings, no Memory before the stored up material, no Understanding before the concepts, &c."Aphorumen zur Psychologic : Werke, vii. 611. THE LIMITATIONS OP KNOWLEDGE. 217 of something distinct from the process ; and thus two aspects of one and the same phenomenon are held to be two distinct phenomena. Because we abstract the material of an object from its form, considering each apart, we get into the habit of treating form as if it were in reality separable from material By a similar illusion we come to regard the process (of thinking) apart from the product (thought), and, generalising the process, we call it Mind, or Intellect, which then means no longer the mental phenomena condensed into a term, but the source of these phenomena. This illusion is further strengthened by the metaphors in which it is commonly expressed. We speak of the Mind being furnished with material by Sense ; or we liken it to a loom which weaves the threads of Experience into a wondrous web. But if we substitute for these meta- phors another more nearly resembling the fact, and instead of a machine take the vital organism for com- parison, we may parallel the aphorism : " Nothing in the Intellect not previously in Sense," by the aphorism : " Nothing in the Organism not previously in Food." On hearing this latter statement, a biologist who had no conception of the evolution of an organism, individ- ual and ancestral, might patiently ask : " But whence came this organism ? whence its power of fashioning the food ? I see no trace of the organism and its functions in the nutritive materials ; hence I conclude that these pre-exist, and because they are pre-existent there is the possibility of nutritive materials becoming food." It is thus the d, priori psychologist asks : Whence the Mind and its Forms of Thought 1 Whence those conditions which render it possible for sensitive impressions to become Experience ? 218 PROBLEMS OF LIFE AND MIND. The answers to such questions must depend on whether we are considering the functions, or their genesis. It is indisputable that every particular man comes into the world with a heritage of organised forms and definite tendencies, which will determine his feeling and thinking in certain definite ways, whenever the suitable conditions are present. And all who believe in evolution believe that these forms and ten- dencies represent ancestral experiences and adapta- tions ; believe that not only is the pointer born with an organised tendency to point, the setter to set, the beaver to build, and the bird to fly, but that the man is born with a tendency to think in images and symbols according to given relations and sequences which constitute logical laws, and that ivhat he thinks is the necessary product of his organism and the exter- nal conditions. This organism itself is a product of its history : it is what it has become : it is a part of the history of the human race, and in so far resembles that of other members of the race ; it is also specially individualised by the particular personal conditions which have distinguished him from his fellow-men. Thus resembling all men in general characters he will in general feel as they feel, think as they think ; and differing from all men in special characters, he will have personal differences of feeling and shades of feeling, thought and combinations of thought. All this is equally true of the organism and its food. The body is built up out of elements furnished in the food, and this not simply by a juxtaposition of the elements, but by their selection, combination, re- combination, and assimilation (or making like) ; and this assimilation is rigorously determined, 1, by the THE LIMITATIONS OF KNOWLEDGE. 219 special properties of the elements themselves in these relations ; and 2, by the special properties of the tissues which assimilate them; and these latter are deter- mined by inherited tendencies of the organism. Thus only those elements in the food supplied which admit of being assimilated under these conditions are in- corporated in the organism, and help the growth and preservation of the organism ; the other elements are rejected, and are so to speak non-existent for the organism. The case is parallel in mental assimilation. The re- actions of Feeling are determined by the general laws of Sensibility and the special modes of the individual. The Mind is built up out of assimilated experiences, its perceptions being shaped by its pre-perceptions, its conceptions by its pre-conceptions. Like the body, the Mind is shaped through its history."' It is in this sense and this only that we ought to speak of Intellect as a process apart from its products, and con- tinue the metaphor of sensations being the food of the Intellect. Food, regarded objectively, is something not belonging to the organism ; although, strictly, a substance never is food except in becoming part of an * GEORGE ELIOT in The Spanish Gypsy expresses a profound truth in saying : " What ! shall the trick of nostrils and of lips Descend through generations, and the soul, That moves within our frame like God in worlds, Imprint no record, leave no documents Of her great history ? Shall men bequeath The fancies of their palates to their sons, And shall the shudder of restraining awe, The slow wept tears of contrite memory, Faith's prayerful labour, and the food divine Of fasts ecstatic shall these pass away Like wind upon the waters tracklessly ?" 220 PROBLEMS OF LIFE AND MIND. organism. In like manner Sensation is held to imply an element foreign to Mind, in contradistinction to Thought, which like the air we breathe seems part of ourselves. It is reflection and experiment which convince us that the air is a material object capable of being weighed and measured. It is reflection and experiment which convince us that Thought is an em- bodied process, which has its conditions in the history of the race no less than in that of the individual 16. Thus explained the doctrine of the sensational- ists may be accepted; all ideas may have a sensible origin assigned them when Sensation itself is under- stood to involve the primary condition of an organised structure whose function is logical * (i. e., constituted by the grouping of neural units) and whose aptitudes are inherited Experiences. And, thus explained, the doctrine may be reconciled with all that is valid in the a priori hypothesis, namely, that which insists on the necessary co-operation of logical processes with organised aptitudes. The crude sensational doctrine is equivalent to the crude statement that the Organism and its functions are given in the food. Whether any reputable thinker ever really main- tained this doctrine, may reasonably be doubted ; many writers have seemed to maintain it, owing to the im- perfect precision of their language; yet all would admit that no analysis of food, irrespective of the Organism and its assimilative processes, would yield an explanation even of food, much less of vital pheno- mena ; nor would analysis of external stimuli, irrespec- tive of the sensitive mechanism, yield an explanation * To be fully explained in the Problem on Feeling and Thought. Mean- while see Psycholo ical Principles, 24, 25. THE LIMITATIONS OF KNOWLEDGE. 221 of Sensation, much less of higher phenomena. The resistance of the d priori school to such crude explana- tions has been of decided utility. Eespecting the so-called Mental Forms both schools are right, though standing at different points of view. The psychological fact tells us that the Forms are con- nate, therefore d priori; the psychogenetical fact tells us that the Forms are products of ancestral Experience, and therefore d posteriori. But the vital question is not whether we have modes of feeling and thinking which determine the nature of our feelings and thoughts, but whether we can have any knowledge of things which have not been felt, i.e., whether there is a sensible basis and sensible test requisite for every conception, or whether a Supra-sensible is knowable. 17. The transformations which hypotheses undergo have been instructively illustrated by Whewell. "When a prevalent theory is found to be untenable, and conse- quently is succeeded by a different or even by an oppo- site one, the change is not made suddenly or completed at once, at least in the minds of the most tenacious adherents of the earlier doctrine ; but is effected by a transformation or series of transformations of the earlier hypothesis, by means of which it is gradually brought nearer and nearer to the second ; and thus the defen- ders of the ancient doctrine are able to go on as if still asserting their first opinions, and continue to press their points of advantage, if they have any, against the new theory. They borrow or imitate, and in some way ac- commodate to their original hypothesis the new explan- ation which the new theory gives of the observed facts; and thus they preserve a sort of verbal consistency ; till the original hypothesis becomes inextricably con- 222 PROBLEMS OF LIFE AND MIND. fused, or breaks down under the weight of the auxiliary hypotheses thus fastened upon it in order to make it consistent with the facts." * Such has been the case with the hypothesis respecting the origin of know- ledge. Each school has modified its views to include what is valid in the doctrine of its opponent. When the arguments of Gassendi and Hobbes made Descartes aware of the manifest impropriety of supposing that the infant came into the world ready furnished with ideas of objects which could only be presented to Sense, and of ideas which could only be furnished by combin- ations and abstractions from sensations with ideas of Geometry before there had been sensible experiences of Extension, &c., the philosopher declared that his mean- ing had been misinterpreted. He declared that he never conceived that the infant had more than an innate faculty of acquiring such ideas under suitable conditions. His admirers and followers have been at some pains to show that this was his meaning. Thus interpreted, the doctrine of innate ideas amounts to the evident proposition that the native construction of the human mind is such that when given conditions are present given results must follow when objects are apprehended there will be certain ideas formed, and when certain propositions expressive of the relations of such ideas are stated, the truth of such propositions is seen at once. No sensationalist would demur to this. 18. Let us for a moment glance at the statement of this doctrine by two illustrious defenders of it. Schel- ling argues thus : All knowledge in as far as it is the product of the Ego is d priori ; but in as far as it is unconsciously produced it is d posteriori. There are * WHEWELL : Philosophy of Discovery, p. 493. THE LIMITATIONS OF KNOWLEDGE. 223 therefore d priori concepts, without there being innate concepts. The concepts are not innate ; but our nature and its mechanism is innate.* Leibnitz is equally explicit : " Philalethe. S'il y a des ve'rites innees ne faut il pas qu'il y ait des pense'es inndes ? Theophile. Point du tout, car les pense'es sont des actions, et les connaissances ou les ve'rites, en tant qu'elles sont en nous quand meme on n'y pense point, sont des habi- tudes ou des dispositions." In this statement of the doctrine the absurdity is escaped ; but at the same time its significance vanishes. We have only to open Locke to see that in this form he frankly accepted it. " I imagine," he says, " any one will easily grant that it would be impertinent to suppose ideas of colours innate in a creature to whom God hath given sight and a power to receive them by the eyes from external objects : and no less unreason- able would it be to attribute several truths to the im- pressions of nature and innate characters when we may observe in ourselves faculties fit to attain as easy and certain knowledge of them as if they were originally imprinted on the mind." Indeed the very distinction on which stress is laid, between capacity and know- ledge, is thus expressed by Locke : " The capacity they say is innate ; the knowledge acquired. But then to what end such contest for certain innate maxims ? " 1 9. This is the real point : the ' capacity to acquire ' must be presupposed in the case of maxims avowedly the products of Experience, no less than of maxims * SCHELLING: System des Trans. Idealismus, p. 316-18. And elsewhere in the Erster Entwurfeines Systems der Naturphilosophie, p. 15, he says : " Sobald ich die Einsicht in die innere Nothwendigkeit eines Erfahrung- satzes erlange, wird er ein Satz ct priori." Comp. HEGEL in his critique on Locke : Gesch. der Phil., iii. 421. 224 PROBLEMS OF LIFE AND MIND. declared to be anterior to Experience ; on the other hand, " the knowledge acquired " must be the product of Experience in both cases. Leibnitz says that when a man at fifty learns the proposition of the square of the hypotenuse " he acquires an innate idea ; " and thus all the truths of Geometry are innate, though millions of men never acquire them. This position, which was reproduced by Whewell in his controversy on the sub- ject with Mr Mill and myself, * simply amounts to asserting that the mind is so constituted as inevitably to form certain conclusions under certain conditions. Who ever doubted this ? It is wholly irrelevant. We are so constituted that under certain conditions inevitably we have sensations of colour, sound, taste, &c. ; yet no one considers the ideas of colour, sound, and taste to be innate. The mind is so constituted as inevitably to conclude (until better instructed) that the sun turns round the earth, moving from east to west, but no one would admit this conclusion to be innate. It is with the functions of our intellectual organs as with the functions of our vital organs when the organ is mature, is healthy, and is stimulated, its action is irresistible ; and when similar organs in various organ- isms are stimulated under similar conditions, the action is in each case similar. 20. That all men should form the same conceptions mathematical or metaphysical under conditions that are universal, is not surprising ; but it is surprising, at first, to observe the strange yet identical conceptions formed by lunatics under external circumstances of the widest dissimilarity ; and the surprise only ceases when we discover the cause of this identity to be the * Compare his Philosophy of Discovery, p. 530. THE LIMITATIONS OP KNOWLEDGE. 225 similarity of cerebral conditions. In the course of my observations in English and German asylums I have been forcibly impressed with the fact, abundantly illus- trated in the records of Insanity, that patients belong- ing to very different classes of society and to different nations, have precisely similar hallucinations, which they express in terms so closely alike, that the one might have been a free translation of the other. The pauper lunatic in England will often have the same illusion as the insane German merchant ; and the in- sane soldier in Bohemia will seem to be repeating the absurdities of the insane farmer in Sussex. Not only does the fact of cerebral congestion determine hallu- cination in the Englishman as in the German, but de- termines the precise form which that hallucination will take. Twenty different patients of both sexes and of different age, country, and status, will be found having similar morbid sensations ; and will all form a similar hypothesis to explain what they feel. Not only will they agree in attributing their distressing sensations to the malevolent action of invisible enemies, but will also agree in describing how these enemies molest them; even when such imaginary explanations take peculiar shapes for example, that the enemy blows poisonous vapours through the key-hole, or chinks in the wall, strikes them with galvanie batteries hidden under the table, roars and threatens them from mnderground cellars, &c. To hear in Germany a narrative which one has already heard in England, gravely particularising the same preposterous details, almost as if the thoughts of the one were the echo of the thoughts of the other, has a startling effect. I do not refer simply to the well-known general types of hallucination in which VOL. i. p 226 PROBLEMS OF LIFE AND MIND. patients fancy themselves emperors, Christs, great actors, or great statesmen, or fancy themselves doomed to per- dition, made of glass and liable to break in pieces if they move, I refer to the singular resemblance notice- able in the expression of these forms, so that one patient has the same irrational conceptions as another.' 55 ' This identity of conception rests on identity of cerebral congestion. Kemove the congestion and the halluci- nation vanishes. INSTINCT. 21. And here I will digress a little on the subject of Instinct, which, because it is so frequently cited to prove the doctrine of Innate Ideas, may best serve to illus- trate the doctrine of evolution. The marvel and mys- tery of Instinct naturally render it a favourite topic in the writings of those who oppose the experiential School. Instinct is often regarded as so superior to Intelligence in the certainty of its action, that nothing except Creative Wisdom is admitted in explanation of it ; while from other sides it is regarded as so removed from all community with Intelligence, that it is de- clared to be the blind action of a mechanism, not the operation of a rational Soul. Psychogenesis seems to me to teach the direct contrary of all this. It teaches that Instinct is organised Expe- rience : i.e., undiscursive Intelligence ; that is to say, while the neural and logical processes are the same in * " On ne vent pas s'apercevoir que les mgmes sens, les memes operations, et les memes circonstances doivent produire partout les memes effets. On veut absolument avoir reeours & quelque chose d'innde ou de naturel qui precede 1'action des sens, 1'exercise des op^ra- tions de I'&me et les circonstances communes. " COJIDILLAC : L'Art de Penser, ch. v. p. 47. THE LIMITATIONS OF KNOWLEDGE. 227 both, the operations in what is specially termed Intelli- gence are facultative, and involve the element of choice in the selection of means to ends : Intelligence is therefore discursive ; whereas in Instinct the operations are fixed, uniform, with no hesitation in the selection of means. That Instinct, although in the individual it precedes Experience, is a product of what was Experience in the ancestral organisms from which the individual has in- herited his structure, may best be shown by tracing its genesis from actions that at first were tentative, in other words intelligent. We have already (Psychological Principles, 52) established the needful distinction be- tween Intelligence and Intellect, and characterised the former as the discrimination of means to ends the guidance of the Organism towards the satisfaction of its impulses ; and (ibid., 30 and 74) we have dis- tinguished Instincts from Impulses solely on the ground of the former being guided by discernment of relations. So that the three orders of phenomena may be thus characterised : in cases where there never was an alternative open to an action, the action being the necessary activity of the stimulated organ as in Secretion, Respiration, &c., the action is impulsive; in cases where there was once an alternative, and when the action may still be controlled or modified in consequence, and is always guided by discernment of relations, the action is instinctive : however fixed now, it was not always so, and will vary with variations in the conditions; in cases where there are alternatives which may determine the action, the means being various and those that are selected in one case being rejected in an- other, the action is intelligent, discursive. Thus the nutritive Impulse which urges an animal in search of 228 PROBLEMS OF LIFE AND MIXD. food is to be distinguished from the Instinct which causes it to select only one kind of food from out of several kinds accessible, all of which would be nutritious, or causes it to procure that one kind only in the ways followed by its ancestors, though many other ways are really open to it. The peculiarity of Instinct is that although guided by discernment of relations which is intelligent, it is restricted in its pathway and rendered undiscursive by an organised tendency of structure re- sulting from ancestral restrictions. The character of o uniformity so often insisted on, arises naturally from the success of the means chosen ; the Impulse having been satisfied by the object selected, no other object is sought, and the choice once made is made for ever. But that the object was chosen is proved by the fact that when, under other conditions, it no longer satisfies the Impulse, it is rejected, and another sought ; more- over, not only is the old object rejected when it ceases to satisfy the Impulse, but a new object will be selected in preference if it gratifies the Impulse. Thus we see insects in our conservatories select their food and nidus among tropical plants which could not live in the open air which these insects were born and bred in : thus indi- genous plants which have formed the nidus and the food for generation after generation, are neglected in favour of the new plants which the insects now first discover. Every one who has watched birds knows that they always select the best materials for their nests, and will leave untouched material they and their kind have been accustomed to select, if softer material is at hand. The fact of choice is further confirmed by the fact that Instincts are subject to illusions as Reason is. I THE LIMITATIONS OP KNOWLEDGE. 229 shall hereafter have occasion to specify many striking examples. The daily facts of Habit show how easily tenden- cies become organised, how the actions which at first were tentative, laborious, slow, become inevitable, easy, rapid ; and the notorious facts of Heredity show how habits once organised may become transmitted to de- scendants, so that the unnatural action of ' begging/ when a dog is taught to perform it, may become a natural action in its descendants, requiring no teaching. Nay this very process underlies all development. The voluntary actions become involuntary, the involuntary become automatic, the intelligent become habitual, and the habitual become instinctive. It is the same in the higher regions of Intellect : the slow acquisitions of centuries of research become condensed into axioms which are intuitions. However undiscursive Instinct may be it has always the intelligent character of discernment of relations and consequent control. For example, the instinct in an angry man to strike the offender, or in a dog to bite, is not, as Bossuet* and other writers suppose, a blind impulse unprescient of means and end ; on the contrary, the man, however angry, will not strike an offender before whom he stands in awe, or for whose weakness he has pity ; nor will the dog bite his master. It is instructive to observe a dog whose tail is pinched by * "Un arc bande ne tend pas plus & tirer que le corps d'un homme en colere a frapper 1'ennemi. ... La seule impression de 1'objet opere en nous cette action. . . . Les actions animales, s'operent par la seule force de 1'objet meme plus surement qu'elles ne feraient si la reflexion venait s'y meler." BOSSUET : De la Connaissance de Dieu, ck. iii. 2, ch. v. 3. 230 PROBLEMS OF LIFE AND MIND. one he loves ; the pain excites the impulse to bite, the mouth is rapidly brought down upon the offending fingers, but the biting impulse is restrained, and the teeth do not close on the fingers ; whereas if it is a stranger's fingers that have caused the pain, the biting instinct has free play. 2 la. The general notion that voluntary movements arise out of involuntary movements is only acceptable when by Volition is meant the determination of an im- pulse by a guiding idea ; but if we disengage it from this place in the intellectual region, and restore it to its primary position in the Logic of Feeling and other- wise we must deny Volition to animals and infants it seems to me demonstrable that the movements now involuntary were originally voluntary, precisely as the instinctive actions were originally intelligent, the un- discursive, discursive (Psychol. Principles, 31). One illustration may suffice. The movements of the eye are generally acknowledged to be involuntary ; that they are originally voluntary, and have still their guidance in discriminative sensation, and their pole- star in the external object, will be evident to any one who studies their mechanism.* Now since we know that many Instincts which are manifested as soon as the organisms have acquired the requisite development and are appropriately stimu- lated, were originally acquired in ancestral experiences, a striking example being that of the instinctive terror of man felt by animals, a terror which was organised in their immediate ancestors, and was ab- sent from their remote ancestors since we know that Instincts like many Diseases are due to registered *See HELMHOLTZ : Physiol. Optik., p. 473-4 and 772. THE LIMITATIONS OF KNOWLEDGE. 231 modifications of structure, transmitted by Heredity, and since these registrations are themselves acquired results, the conclusion that all Instincts are acquired becomes irresistible. Indeed we have only to remember that every mental manifestation is simply the activity of an organised structure, and is rigorously determined by that structure, to see that if the present structure is acquired through successive modifications of pre- existent structures, the present manifestation must have been acquired. It is forgetfulness of this cardinal prin- ciple, of the necessary dependence of the dynamical effect on the statical conditions, which renders the in- terpretation of some familiar facts so uncertain. Thus when the helplessness of the human infant is con- trasted with the helpfulness of the young animal, so that what requires a long initiation of experience in the one, is seen to be present from the first in the other, and the necessity which the infant is under of learning to walk, learning to see, learning to localise its sensations, is not observable in the rabbit or the bird, it is concluded that these actions have a different genesis in each. Hence one party holds that our perception of Space is innate, because the bird manifests it on quitting the shell ; another party holds that our per- ception of Space is acquired, because the infant has to learn how to see, and how to estimate positions. The truth seems to be that the bird quits the shell in a far more developed condition than the infant on entering the world, has its organism and its visual organs more ready to enter upon their normal activities, and therefore more quickly manifests what the infant will only manifest when a corresponding development has taken place. On the other hand, in observing 232 PROBLEMS OF LIFE AND MIND. how the infant slowly acquires the perception of Space we learn what has been the process of registration in the development of the bird-structure. The state of the infant organism, before it has been modified by the registration of changes produced by reactions on exter- nal stimuli, represents what was the state of the ances- tral organism before it had been so modified. Embry- ology teaches us that the embryonic phases of the higher animals repeat the phases of development at which the lower animals are arrested. It is because the imma- ture brain of the infant represents a stage when the Experience was immature, that the infant cannot mani- fest aptitudes which depend on subsequent Experience ; and it is because the stages of subsequent development will take place under similar conditions to those which have occasioned the development of the parents, that the functions of the infant will in time come to resemble the functions of the parents. Let the infant be devel- oped under dissimilar conditions, and it will propor- tionately deviate in structure, consequently in functions, from the parents. A child born blind will bring with it the requisite conditions for subsequently acquiring the perception of tactual Space, but will obviously never acquire the perception of optical Space. A child born deaf and dumb will bring with it the conditions requisite for the acquisition of visible and tactual symbols, but not for the acquisition of verbal symbols. To these organic conditions let us now add the external conditions. A child born with eyes, but kept in con- stant darkness, or with only intermittent and brief ex- citations of light, or born with vocal and auditory organs, but in a society of deaf and dumb companions, rarely hearing the speech of man this child will never THE LIMITATIONS OP KNOWLEDGE. 233 acquire the perception of visible space, nor the use of verbal symbols which characterise ordinary men. What the child brings with it into the world is an immature organism which under similar conditions will develop into an organism similar to that of other men. 216. How intimately the functions depend upon the organism may be illustrated in this striking example : The tadpole of the salamander is a vegetable feeder; although it is also an animal feeder, it is not exclu- sively nor mainly this ; but in its mature phase, when it has acquired its distinctive structure as a salamander, it is wholly an animal feeder, and cannot be induced to take vegetable food, even when starving. There is one kind of salamander, (salamandra atra,) which is peculiarly interesting from the fact that it is born a salamander, and not a tadpole, passing through its tadpole metamorphoses while still in its mother's womb. Now no one will dispute that the selection of food is an Instinct, and that one animal is herbivorous, another carnivorous, just as one animal is aquatic, another am- phibious, and a third terrestrial, in accordance with its Instinct. Well, this salamander which is instinctively carnivorous, is in its tadpole stage instinctively herbi- vorous and carnivorous. I found that if it were taken from the womb while still a tadpole, it would live in water, and feed on vegetable and animal substances. Let it complete its metamorphoses, within the womb, or without, and no sooner does it acquire the organisa- tion of the salamander than it acquires the carnivorous Instinct. Again : a pigeon has the Instinct to preen its feathers, and to sleep with the beak under its wing. It does not manifest these tendencies from the first, but always acquires them sooner or later ; when once ac- 234 PROBLEMS OF LIFE AND MIND. quired, these actions are performed even after its cere- bral lobes have been removed ; but it never acquires them if the cerebral lobes be removed before the mechanism has been established. Here we have In- stincts manifestly acquired, just as the child acquires the Instinct to scratch itself when it itches ; being for a long while unable to localise its sensations, and con- sequently unable to scratch itself however it may itch, it does nevertheless inevitably, in the course of time, acquire the Instinct. But compare this with the same Instinct congenital in animals who are able to scratch themselves from the first. So indubitably is this ten- dency an organised inherited tendency that it is mani- fested even when some congenital imperfection prevents its perfect realisation. Thus Gudden had a rabbit born with paralysis of the hinder legs, incapable therefore of scratching, and this rabbit which had never scratched itself would, when tickled, turn its head to and fro towards the motionless hinder legs ; thus in part realis- ing the inherited tendency which it was incapable of completely carrying into effect."* These, and multitudes of other examples which might be cited, prove, what is evident theoretically, that the manifestations, whether under the form of perceptions or instincts, are rigorously determined by the state of the Organism. Indeed the Organism is an ensemble of statical conditions, and its dynamical tendencies vary with these. It is thus that we see temporary states successively manifesting tendencies which are classed as Instincts ; and the epileptic patient may be observed passing successively through phases which manifest homicidal, kleptomaniacal, and pyromaniacal Instincts, * See Archiv fur Psychiatric, 1870, ii. 697. THE LIMITATIONS OF KNOWLEDGE. 235 which are temporary if their statical conditions are temporary. Or, since this illustration may be disputed, consider the periodicity of the sexual Instinct in ani- mals, which is assuredly due to a periodicity in the statical conditions. But although the sexual Instinct is less disputable than those fleeting manifestations observable in Insanity, I adduce the evidence of the latter for the sake of illustrating the position that Experience depends on the registration of Feeling, and exists only so long as the registrations, i.e., modifications, exist. For many of these passing states of Insanity, how- ever violent their manifestations, are forgotten like the visions of a dream, when the abnormal conditions give place to normal conditions, and the over-excited brain resumes its former state. If the statical modification become permanent, there is registration of the feelings, and the patient is permanently insane; if they are fleeting there is no registration, and the patient returned to his normal state has no Experience of all that occurred during his abnormal state. 22. We do not usually class any of the fleeting mani- festations under the general term Instinct, though ob- viously some of the Instincts are but temporary mani- festations of temporary states, nor do we class any manifestations that are peculiar to individuals as In- stincts, but rather as Idiosyncracies. Only those mani- festations that are common to the species, and are responses to external stimuli of common recurrence, are classed among the Instincts. There are certain statical conditions which are invariable such are those dynamically represented in Space, Time, Causation, &c., which may be set apart, and considered, on this ac- count, as specially entitled to the character of cl priori 236 PROBLEMS OF LIFE AXD MIND. Mental Forms, not indeed in the Kantian sense, but in the sense in which Biology understands organised forms. What concerns us here, however, is not the psychologi- cal but the psychogenetical interpretation not whether man comes into the world with an organised structure the activities of which necessarily lead to the percep- tions of Extension, Duration, Causation, &c., and also to the conceptions of Space, Time, Cause, &c., but whe- ther these perceptions and conceptions have any higher source and deeper validity than the perceptions and conceptions which arise from individual experiences. Neither observation nor reflection warrants the suppo- sition that the infant, in spite of inheritance, has on entering the world innate ideas of Space, Time, Causa- tion; what is innate, or connate, is the structure which will react under stimulus in certain definite ways ; and these reactions will depend on the degree of develop- ment which the structure has acquired. The infant whose optical organs are imperfect will never react on the stimulus of light in the same way as another infant whose organs are more developed. At birth no child sees. It usually takes several days before the child makes any movement of the head towards the light, and four or five weeks before he learns to converge the axes of both eyes.""" But could the infant see at birth, this would not indicate that the perception of Space or of external objects was innate ; only that the structure was ready for its function ; and how that structure came to be formed would still remain a question. And * There are great varieties in this and indeed in all other points of de- velopment at birth. Thus BONDERS, whose authority on such a matter is supreme, records a case in which he observed an infant distinctly con- verge the eyes and follow an object only a few minutes after birth. ArchivfUr OptJialm., 1871, xvii. 34 THE LIMITATIONS OF KNOWLEDGE. 237 there is one argument which is decisive. Even if we assume, with the advocates of creation, that the struc- ture was not evolved through modifications impressed on organic substance by successive adaptations of the Organism to the external Medium that the eye, for example, was created, and not evolved by the action of light upon the sensitive surface created with all the powers which it is known to manifest, still there would remain the necessity of this eye being brought into the appropriate relation with the external object; and in the absence of this, in the absence of light to call the energy of the eye into existence, there would be no visual perception, much less an idea of Space. Nor would this be denied ; certainly not by Kant. Yet its admission is an admission of the cardinal principle of the Empirical doctrine, that all perception, consequently all conception, is the product of the reactions of the Organism stimulated by the Cosmos ; which is saying in other words that all our knowledge has its origin in Experience the registration of such reactions. And this is further confirmed by the fact that on the one hand the development of the Organism has its pre- scribed course, any interference with the series of suc- cessive stages causing another form of structure to result, while on the other hand any interference with the normal course of experience will correspondingly affect the result, so that even results which have the fixed character of Instincts may be frustrated by an interruption of the prescribed course of evolution. Many examples might be given, but it will suffice to mention the Instinct of sucking, which is manifested by all mammals very soon after birth. Here is a struc- ture ready for reaction in a particular way directly the 238 PROBLEMS OF LIFE AND MIND. appropriate stimulus is felt. But (the observation had not escaped Harvey) if, instead of being put to the breast, the child be fed from a spoon, in a few days it loses the power of sucking the breast, and can only feed from the spoon. Obviously the explanation of this is that the Organism, having been induced to react in a way unlike the normal way, becomes in consequence so modi- fied that it will no longer react in the normal way even when the normal stimulus is applied.* 23. This digression has been made to fix our notion of what is really valid in the doctrine of Mental Forms, as organised tendencies acquired through suc- cessive experiences; and to disprove the conclusion that the existence of such Mental Forms indicates metempirical sources of knowledge. When we admit the existence of a priori tendencies, we do not admit the existence of d priori truths, i.e., conceptions ot sensible facts irrespective of Experience, or of supra- sensible facts which no Experience could furnish. * Since this was in the printer's hands, some ingenious and instructive experiments have been published by Mr SPALDING (Macmttlan! s Maga- zine^ February 1873 ; compare also the discussions in Nature during the months of March, April, and May), which strikingly confirm what is said in the text respecting the variation of Instincts under varying conditions, and on the effects of any interruption of the normal experiences. Mr SpALDDfG also tells me of a friend of his who reared a gosling in the kitchen away from all water ; when this bird was some months old, and was taken to a pond, it not only refused to go into the water, but when thrown in scrambled out again as a hen would have done. Here was an instinct entirely suppressed. What I have said about the instinctive selection of food is also confirmed by the following observation : " Every chicken, as far as my observations go, has to learn not to eat its own ex- crement. They made this mistake invariably ; but they did not repeat it oftener than once or twice. Many times they arrested themselves when in the very act, and went off shaking their heads in disgust, though they had not actually touched the obnoxious matter." THE LIMITATIONS OP KNOWLEDGE. 2o9 When we admit that there are in the organism stati- cal conditions which must determine the directions of its manifestations, so that every Mind must necessarily feel in certain ways and think in certain ways, we do not admit that the feelings, and the truths which are their results, are engraven on the Mind, and require no excitations from the external world to elicit them; still less that they can reveal to us a world which never was presented in Experience. The Forms of Sense and the Forms of Thought are evolved, as the branches and foliage of an oak are evolved from the acorn. No one now supposes that the oak is ready formed in the acorn, lying there in miniature. The oak is quite as much in the atmosphere and soil ; it really is in neither, but will be evolved from both. Given the two factors an Organism and its Medium and the product will necessarily be evolved ; and will be according as they are. Thus the seed of the poplar, and the seed of the chestnut, are different structures, and will evolve into different trees. We learn by individual experiences, registrations of feeling, rendered possible by ancestral experiences. The individual structural evolution, in its embryonic phases rapidly runs through all the grades of verte- brate development. The individual mental evolution in its early phases likewise runs rapidly through all the general experiences of the race ; and youth acquires ideas, the products of such experiences, by going through similar successions of feeling. What marvel is there that constant conditions acting upon structures which are similar, should produce similar results ? It is in this sense that the paradox of Leibnitz is true, and we can be said " to acquire an innate idea ; " only 240 PROBLEMS OF LIFE AXD MISD. the idea is not acquired independently of Experience, bnt through the process of Experience similar to that which originally produced it The truth that a straight line is the shortest line between two points, is one which millions of men pass to their graves with- out acquiring ; yet it is a truth which may justly be called innate in so far as it lies involved in the sensible experiences from which Philosophy extricates it I mean, it is necessarily given in the Logic of Feeling, before Psychology recognises it as an Intuition.* The rational instinct which makes a man infer a cause wherever he observes a change, is in one sense connate, in another acquired it is the acquired result of a connate tendency, quite as much as the sexual Instinct, which seeks the gratification of desires by union with another, is the acquired result of a connate tendency : both are developed some time after birth, the develop- ment of both requiring a special state of the Organism, and a special excitation of that state. The infant has no more the idea of Causality, than it has the feeling of sexuality. I shall hereafter show that Causality is an inwoven law of Feeling, not primarily an Induc- tion : it may be said to precede Feeling, and render Experience possible, in so far as it is an organised ten- dency of Feeling to connect a consequent with an antecedent ; it may be called an Intuition in so far as it is 'the perception of the relation of equivalence ; and it may be called an Induction in so far as this percep- tion is raised into a conception, and extended from the particular to the general, raised from a fact of Feeling into an universal Law of Xatura * If bees had the Logic of Signs they would know the geometry which fhey // in constructing their cells. THE LIMITATIONS OF KNOWLEDGE. 241 24. With this view of the genesis of d priori truths It is obvious that the ordinary argument which relies on these for an extra-experiential origin and a deeper validity cannot be accepted. True it may be that con- ceptions which demanded centuries of research are no sooner reached than they are seen to be axiomatic, irresistible; but the fact that they required this re- search is sufficiently instructive respecting their origin ; and if their presence in the primary conditions of Feeling be detected, so that we discover them to be inwoven with our earliest experiences, this does nofc give them a higher validity than Feeling. It is Kant's fundamental mistake, which will be elucidated further on, to treat the ct, priori conditions of Knowledge as evidence of our possessing Know- ledge which is itself d priori and metempirical to assume that because knowledge is rendered possible by organic conditions, and these are not present in the external causes of excitation, therefore there is a Knowledge which is anterior to all excitation, independent of all Experience. But if we get rid of this view we may reasonably admit that there must be cL priori conditions which render Know- ledge possible ; and we may also conveniently establish a distinction between d priori and d posteriori know- ledge not that either of them can be supposed to have originated independently of Experience, ancestral and individual, or to be founded on different processes, but that the one embraces conceptions which must inev- itably and always be formed, because their conditions psychical and cosmical are constant, whereas the others are contingent, depending on variable conditions. In illustration take Mathematics and Biology. The VOL. i. Q 242 PROBLEMS OF LIFE AND MIXD. former is an d priori science, not that it is in any sense independent of Experience (see Chap. XIII.) but that its data and results are invariable : the logical conditions and the external conditions are constants : what is seen to be true of one circle is seen to be true of every circle ; therefore the knowledge of one includes d priori the knowledge of all, and there is no need of experi- ment or comparison to determine whether each new case is identical with the known cases. Not so with Biology except when its abstract propositions are dealt with. The state of our scientific experience is here a variable factor, and the external conditions are likewise variable. We can imagine a variety of hy- potheses to explain every unexplained phenomenon, and it is only by successive tentatives that we reach any reliable explanation. More than this, the most accurate knowledge of any one phenomenon does not enable us d priori to conclude respecting every other that may resemble it ; each fact demands d posteriori verification of its explanation, since we cannot always be sure that it resembles in all respects those which it is seen to resemble in some respects. Kant erred I think in two ways : first, in accept- ing the traditional Dualism which regarded Mind in the light of a separate entity, having its inherent Forms, or Laws, which had no community with the Laws of the Cosmos ; secondly, in limiting the number of these Forms, and not seeing that as evolved products they were necessarily enlarged by increasing Experience. With this rectification, we may accept the position that there are d priori Forms of Sensibility necessarily inherent in the organised structure; and these, which may be classed THE LIMITATIONS OF KNOWLEDGE. 243 under Forms of Feeling and Forms of Thought, are correctly said to be connate, in precisely the same way that the vertebrate form, or the special forms of the several organs are connate. Since the mani- festations of the organism must be determined by its modes of reaction, obviously the experience of each individual will be rendered possible by the con- nate Forms ; and if we constructively anticipate, what must necessarily result when this organism is placed under stimulus, we may say that the resulting experience, or knowledge, is connate. In this sense it is true that man brings with him into the world the potential knowledge that a straight line is the shortest line between two points, and that every effect must have a cause ; just as he brings with him the potential knowledge that sugar is sweet, and roses are red. But in no other sense. The Mental Forms are general and special, i.e., common .to an entire group of feelings, and particular to special groups. The alcrd^ra. KOIVCL, or analytical Forms of Feeling, are Extensity, Intensity, Pleasure (and its correlative Pain), Duration, Motion, Difference. There is no sensation which does not involve magni- tude, degree, a pleasurable or painful quality, a motor quality, a duration, and a discrimination separating it from other sensations. From these are abstracted the vorjTo. KOiva, or analytical Forms of Thought such as Quantity, Relation, Change, Coexistence, Succession, &c., which are raised from the Logic of Feeling into the Logic of Signs. What may be called the particular Forms are those of the Special Senses, such as Colour, Odour, Taste, &c. But these Mental Forms, like the so-called Laws of 244 PROBLEMS OF LIFE AND MIND. Nature, are not to be conceived as antecedent and independent realities ruling mental and cosmical phe- nomena. They are only d priori in our theoretical constructions. They are not properly speaking con- ditions which precede the phenomena, but modalities tinder which the phenomena appear, and which Analy- sis separates, and then assigns them logical priority. 25. We may here bring this discussion to a close in the hope that it has exhibited the promised reconcilia- tion between the experiential and d priori schools, by elucidating what is valid in both, and rectifying what is erroneous in both. Although I have argued the ques- tion in my own way, it is proper to add that the point of view here advanced is historically to be assigned to the labours of Gall, some modern physiologists, and above all Mr Herbert Spencer. In Gall's system it is a vital point that our various aptitudes, instincts, and faculties are connate. He particularly distinguishes it from the hypothesis of innate ideas and innate prin- ciples, on the one hand, and from that of mere passive capacities on the other as if the organism were a block of marble ready to be shaped according to the fancy of the sculptor.* But Gall's analysis, apart from many imperfections, is simply psychological, * " J'entends par dispositions inne*es, des aptitudes industrielles, des in stincts, des penchants determines, des faculte*s, des talens determines. J'entends que chaque organe cerebral est empreint d'une tendance de"ter- minee ; que chaque organe jouit d'un apercu iute'rieur, d'une force, d'une faculte", d'une impulsion, d'un penchant, d'un sentiment particuliers. Ici rien n'est vague et incertain, ni d'une influence exte*rieure, ni d'une ab- straction interieure. Aussitot que les organes relatifs ont acquis leur par- fait developpement et leur entiere activite", les fonctions qui en resultent, sont aussi determinees que les dispositions elle memes dont ces organes Bont les depositants." GALL : Sur les fonctions du cerveau, 1822, L 63. Comp. also p. 66-70. THE LIMITATIONS OF KNOWLEDGE. 245 whereas Mr Spencer's is psyckogenetical. He not only recognises the existence of the modalities, he explains their genesis ; and by showing that the con- stant experiences of the race become organised tenden- cies which are transmitted as a heritage, he shows that even such d priori forms as those of Space, Time, Causality, &c., which must have arisen in Experience, because of the constancy and universality of the exter- nal relations, are necessarily connate. Just as the optical structure of the eye has been, so to speak, fashioned by the external influences incessantly modi- fying the primitive tissues, and thereby rendering possible and inevitable the functional reaction of that organ ; so the cerebral structure has been fashioned by the necessities of internal adaptation to external in- fluences, and thus the constant relations of Space, &c., organised in us. Such is one of the many profound conceptions with which this great thinker has enriched Philosophy; and it ought to have finally closed the debate be- tween the d priori and the experiential schools in so far as both admit a common ground of biological inter- pretation ; though of course it leaves the metempirical hypothesis untouched. The metempiricist not only maintains that there is a something in the mind over and above the mere capacity to know, something not belonging at all to the Organism, but he concludes that we have evidence of this in a higher source of know- ledge than can be gained through Experience of the individual or the race. He maintains that a mark exists by which this can be recognised ; and that mark is the twofold character of Universality and Necessity. I shall hereafter devote a chapter to the discussion 246 PKOBLEMS OF LIFE AND MIND. of this point. Here I can only notice its bearing on the question respecting innate ideas. Obviously since the experiential doctrine admits the universality and neces- sity of mathematical truths (though Mr Mill and some others would restrict even these), this character will not of itself suffice to prove the d priori position. The origin of these truths still remains a question. Both schools agree that the mind is so constituted as irresis- tibly to form these conclusions when experience pre- sents the sensible occasions; both schools agree that until such sensible occasions are presented no such conclusions can be formed. The d priori school main- tains that although Experience may be necessary to call the latent truths into emergent consciousness, it only calls them out, it does not originate them, for Experience itself is only rendered possible by their pre-existence. Let us view this hypothesis in a parallel case. Chlorine is so constituted that whenever it combines with hydrogen there is formed hydrochloric acid. From this a metempirical chemist might deduce that hydro- chloric acid is innate in chlorine, since chlorine has within it something which shapes the hydrochloric acid into hydrochloric acid. This something is itself neither chlorine nor hydrogen, nor is it a combined result of the two, but a something which renders the combination possible. The positive chemist is aghast at such a deduction ; yet if we replace the terms hydro- chloric acid and chlorine and hydrogen, by the terms Experience and sensible perception, the argument will be that of the d priori school. That school affirms that there is a something independent of the chlorine and the hydrogen, namely Affinity, and it is this which combines the two gases in hydrochloric acid. Affinity THE LIMITATIONS OP KNOWLEDGE. 247 is neither the gases nor their product, but a power which renders the product possible. 25a. I do not pretend in this place to discuss the ar- guments on which the d priori school defends its thesis ; anything I might have to say on such a subject would be necessarily based upon psychological analysis which can only be attempted at a later stage. What I am here concerned with is to break down the barriers which have so long prevented the two schools from meeting on a common ground. This is effected when the admission is gained that all ideas are the products of two factors, the Subject and the Object, and that no ideas belong exclusively to one of the factors. "Whether by Subject we understand the Mind and its connate apti- tudes, or the Organism and its organised tendencies, matters nothing in the present question ; the admission required is that there is a predisposition to act in cer- tain necessary ways whenever sensible stimuli call the mind into activity. Descartes and Leibnitz, as also Kant and his followers, expressly declare that no truths, not even d priori truths, are seen (emerge in conscious- ness), unless the relations formulated are presented in Experience. The co-operation of the Object is there- fore demanded. What they insist upon is that the mind brings with it at birth a structure which renders certain conclusions necessary. This admitted, there arises the further question : why is the proposition that acids redden vegetable blues, of inferior validity to the proposition ' two parallel lines cannot enclose space ' \ The first is said to be gathered from Experience, and therefore of inferior validity to the second, which is shown not to belong to Experience because of its uni- versal validity. This is an interesting question, which will hereafter occupy us ; meanwhile observe that the 248 PROBLEMS OF LIFE AND MIND. answer cannot properly rest on an assumed predispo- sition of the mind, since that is common to both ex- amples, the mind having a native predisposition towards all the results of Experience, when the terms of those results are presented. The body has likewise a native predisposition to move in any direction which is free from obstacles ; it is the existence of obstacles, together with the direction of the impulse, which determine what shall be the direction taken by the body. In like man- ner the presence of external relations impresses certain directions on the course of thought, and this course is determined by the disposition and predisposition of the mind- Since then the character by which certain truths are distinguished from others cannot lie in the structure of the Mind itself, it must lie in the nature of the relations presented : in the Necessity and Universality of the re- lations formulated. And this is the character fixed upon. Now without here assuming, what will hereafter be proved, that the celebrated distinction of Necessary and Contingent Truths conceals a fallacy, we may remark that even an admission of the distinction by no means justifies the deduction : and for these reasons, 1, the character of Necessity cannot be assigned as a special mark of native predisposition, innate capacity, but only as a mark of a particular class of objective relations ; 2, the only intelligible meaning of innate capacity by which these ideas are said to be formed is one which irresistibly extends to all faculties and to all ideas. Truths whether universal or particular, necessary or contingent, are still truths evolved in and through Experience, and are subject to all the conditions of Experience. 249 CHAPTER III. THE SENSIBLE, THE EXTRA-SENSIBLE, AND THE SUPRA-SENSIBLE. 26. THE discussion of the origin of Knowledge which has just occupied us is chiefly important in reference to the possible range and validity of Knowledge; although primarily a question of Pyschogeny, and therefore in- teresting only to special students, it is secondarily the vital question of Philosophy, since on it rests the whole of philosophical Method. All that has been written on Method is imperilled if there can be any valid evidence for the existence of an avenue through which knowledge may be reached without recourse to Experience. The metempirical school explicitly, or implicitly, affirms that there is such an avenue, and that it is revealed in Consciousness. Now Psychology being the science of Consciousness, and receiving all its material from Biology and Sociology, we may reduce this great question to something like definiteness by asking whether in the data furnished by Biology, or in the data furnished by Sociology, there is the evi- dence of a metempirical factor ? In the biological phenomena there is assuredly no trace of it. The ani- mal may indeed be said to have Knowledge ; though that is often denied, because of an unwarrantable restric- 250 PROBLEMS OP LIFE AND MIND. tion of the term. But although he has knowledge, i.e., such registrations of Experience as suffice to guide his actions in the satisfaction of immediate impulses, the Animal is not supposed to have speculative knowledge, certainly nothing resembling Science. For him, and for the infant and the rudest savage, Knowledge con- sists of the synthesis of the feelings produced by exter- nal objects. For him the Supra- sensible does not exist, even in Thought. The world for him is simply a, felt world; and his Knowledge never ranges beyond Feeling. We must seek then in sociological phenomena, if anywhere, for the metempirical data. And we shall seek in vain. Neither in Social Statics, nor in Social Dynamics, is there a trace of the Supra-sensible ; but there is a very clear indication of the genesis of its conception, and its position in the world of Thought. If we interrogate History and Science we learn, indeed, that the conception of a Supra-sensible very early arose in the visionary schemes by which men attempted to explain the order of phenomena ; but we also learn that this conception, which was at first only a subtilised expression of Sensible Experience, became indeed less and less like sensibles as the refinements of Abstrac- tion assumed the character of independent entities, then everywhere gradually vanished before advancing Science, so that the progress of each science was accom- panied by the inevitable elimination of every metem- pirical idea. Nothing can be plainer than the teaching of History on this point. Both animals and men have to learn the facts of the External Order with which they come into relation, and to control these facts, as far as possible, adapting them to their needs, and adapting themselves to the facts. But man alone THE LIMITATIONS OF KNOWLEDGE. 251 endeavours to explain the facts, that he may the better control them ; he alone constructs Instruments in consequence of his Knowledge, and greatly enlarges Knowledge by the construction of Instruments. The history of Science, and indeed of Social Development, is the history of this perpetual action and reaction of the creation of Instruments and the enlargement of Knowledge. History records but little of Primitive Man, and nothing of the state of his theories of the External Order ; but it records distinct evidence that in the remote periods which preceded the earliest known form of civilisation there were rude stone imple- ments,* and some means of producing fire. The period between the age of flint axes, and the age of steam- engines, vast though it is, will one day be recognised as a slow evolution of continuous growth, through the successive modifications of Instruments by Knowledge, and of Knowledge by Instruments. For, indeed, Knowledge itself is only an Instrument. That the Primitive Man did endeavour to understand phenomena, at least so far as to enable him to modify them, is obvious. The changes he wrought by his instruments became facts that were known, facts that led him to foresee consequences ; and his powers grew with his knowledge. But at each step he only knew what he had seen, and could foresee. At no stage could he see the invisible, or modify the intangible. He might imagine the presence of invisible Agents, and attempt * It is an interesting fact that the stone is the first approach to an instrument which may be seen in the animal kingdom. MONTAGU ob- serves that the thrush breaks the shells of the univalves on which it feeds by knocking them against a stone ; and many readers must have seen monkeys breaking with a stone the nuts too hard to be cracked with their teeth. 252 PROBLEMS OF LIFE AND MIND. to control them by invocations and incantations ; but this imagination was visionary, and never served the office of Knowledge, except in so far as it reproduced Experience ; nor were any changes wrought in the external visible order by invocations of the invisible Agents. Slowly the conviction emerged that man's power over the external order is limited to his know- ledge of its sensible conditions, and of the means by which such conditions could be rearranged. It is this conviction which has animated Science. But although in the evolution of history we see the supernatural explanations giving place to the meta- physical, and the metaphysical to the scientific (accord- ing to Comte's law), we do not at any stage see that Knowledge was more than a system atisation of Feeling, or that Feeling was more than the reaction of the Organism according to its modes, when stimulated by external forces. There is no trace of a Supra-sensible stimulus, either in our perceptions of the external world, or in those of the social world. I am far from implying that a Supra-sensible does not exist. I only affirm that it does not exist for us as an object of positive knowledge, though forced upon us as a nega- tive conception ; since it could only be knowable by first becoming sensible : it must be positively felt, be- fore it could be positively thought. To know anything is to assign properties to it, and properties involve the co-operation of the subjective factor. Once within the range of Feeling, an object otherwise Supra-sensible comes within the range of Experience. "We have thus prepared the way for the application of RULE I., and this will be more evident when we recog- nise that the main defect in the sensational hypothesis, THE LIMITATIONS OP KNOWLEDGE. 253 and the mainstay of its opponents, lies in the seeming discrepancy between the notorious fact that knowledge does extend far beyond the reach of Perception and the range of Sense ; while on the other hand Psych ogeny, seeming to contradict this, sustains the axiom that all knowledge has its origin in Sense, its limits being the limits of the Sensible. This discrepancy disappears if we divide the field of Speculation into the Sensible World, the Extra-sensible World, and the Supra-sensible World : a division corresponding with our previous distribution of positive, speculative, and metempirical. 27. The Sensible World, or total of sensible phe- nomena, comprises the direct reactions of Sensibility in contact with the External Order. Phenomena I have already defined as the affections of Consciousness with external signs. That we only know things in their effects on us, and through the reactions of our Sensi- bility, may now be taken for granted. Nevertheless it is indisputable that in our conceptions of external things there are elements which cannot be reduced to mere sensation, elements which never were presented to Sense. The Sensible comprises but a small portion of that External Order which is believed to exist. There is therefore an Extra-sensible existence ; and it is revealed through various indications. An examination of the sensitive process discloses that we only receive definite sensations, i.e., groups capable of becoming elements of Consciousness, when the impressions exciting the neural process are of a definite quantity. The neural units which form the elements of such a process are severally non-existent for Consciousness ; they must first be grouped under definite conditions. As a matter of fact, we know that the external must incessantly be impres- 254 PROBLEMS OF LIFE AND MIND. sing the organism : nevertheless the reactions of the organism in Feeling only take place under definite conditions of mass, intensity, and duration. The sen- sory organ needs to be impressed with a certain energy, and for a certain time; neither too small an energy nor too great an energy, otherwise there is not the reaction which is specifically a sensation. There must be a dis- turbance of nervous tension, The vibrations of the Ether when they disturb the tension of the retina, and this disturbance is propagated to the optic centre, pro- duce the sensation of light. But we know that at one end of the spectrum there are vibrations not visible because the pulses are too rapid and the waves too short. At the other end of the spectrum there are also vibrations which are invisible because they are too slow and their waves too long. Eetinal tension is undis- turbed by both these agents. This example shows that among the myriads of impressions to which the retina is subjected only some of them are responded to as Feeling; hence the range of Feeling is quanti- tatively determined. Artificial aids may, and do, ex- tend that range, but the quantitative law remains. 28. And what is true of the eye is true of all the other senses. When a note is sounded by one chord it will set vibrating any other chords which are in sym- pathy with it, and only those. It is thus also external voices awaken sympathetic tones in us. The eyes of animals may possibly be susceptible to vibrations which awaken no response in man.* It is probable that the * This statement needs qualification. Since it was written the experi- ments of M. BERT have shown that the tiny crustaceans common in ponds and popularly called water-fleas (Daphnia) are susceptible to the same luminous vibrations as men and the higher animals, and only to THE LIMITATIONS OF KNOWLEDGE. 255 antennse of insects respond to stimuli which leave us insensible, while stimuli which affect us leave them un- disturbed. Their sensations may begin at that point in the scale where ours end. Be this as it may, the range of Sense in them, as in us, is demonstrably too limited to embrace the objective totality, nay, even to embrace that small portion of it which is in contact with the organism. And if we supplement the deficiency of one sense by the efficiency of another as when the air which is invisible can yet be weighed, taken to pieces, and used to stuff cushions or propel machines, the limits are soon reached. We know there are a thousand tre- mors in the air which beat upon our ears unheard ; and if more sensitive organs are capable of hearing some of these, there must be tremors which no organism can. feel* 29. The Eelativity of Feeling the basis of the Re- lativity of Knowledge must also be taken into account. Thus when a weight, say of three pounds, presses on the hand, a distinct sensation is produced ; but no in- crease in that sensation follows an addition to that weight, if the addition be less than one pound. Al- these. The parts of the spectrum most vividly luminous to us are so to them, and those parts that are invisible to us are invisible to them. Archives de Physiologic, 1869, p. 548. It is nevertheless certain that even among men some retinas are not susceptible to the same vibrations as other retinas ; and sounds become inaudible to some ears while still audible to others. * " Nothing can be more surprising," says HERSCHEL, " than to see two persons, neither of them deaf, the one complaining of the penetrating shrillness of a sound, while the other maintains there is no sound at all. Thus while the person mentioned by Wollaston could but just hear the note four octaves above the middle E of the piano, others have a distinct perception of sounds full two octaves higher. The chirrup of a sparrow is about the former limit, the cry of the bat about an octave above it, and that of some insects probably another octave." 256 PROBLEMS OF LIFE AND MIND. though the pressure of half a pound, nay half an ounce, will be distinctly felt by itself, any quantity less than one pound when added to three pounds will fail to pro- duce the slightest change in the sensation. This im- portant principle which has been experimentally verified in the case of each sense, will occupy us hereafter ; it is here mentioned in illustration of the Relativity of Feeling. Hence may be seen the truth of the old proposition that it is we who create our own world. Diminish the avenues of Sensation, or restrict the varieties of stimuli, and to that extent our world becomes impoverished ; increase the avenues, or enlarge their range either by Instruments or the Mental Instruments called Hy- pothesis, Induction, &c. and to that extent the world becomes enriched. We thus formulate a law which lies at the basis of RULE L, namely : The sphere of Knowledge is limited, l,by Sensible Im- pressions, i.e., definite Sensations ; 2, by Inferences, which are the reproductions and recombinations of such Impressions. The second clause extricates the sensational doctrine from its seeming discrepancy with observation. By it knowledge is carried beyond the range of Sense into the vast Extra-sensible ; and the limitations of Feeling give place to the inexhaustible varieties of Thought. Let us therefore pause a moment to consider the nature of Inference. 30. It is perfectly familiar that the feeling originally due to the objective presence of the stimulus may be revived in the objective absence of that stimulus, by the excitation of the neural process through one or more of the feelings associated with it. The object THE LIMITATIONS OP KNOWLEDGE. 257 is a group of sensibles ; any one of these is capable of reviving the feeling of the others. Inference thus lies at the very root of mental life, for the very combina- tion of present feelings with past feelings, and the consequent inference that what was formerly felt in conjunction with one group of feelings, will again be felt if the conditions are reinstated that the sweetness and fragrance formerly experienced in conjunction with the colour and form of the apple, are again to be revived when the organs of Taste and Smell are brought into relation with this coloured object this- act of inference is necessary to the perception of the object " apple," and is like in kind to all other judgments. Inference is " seeing with the mind's eye/' reinstating what has been, but now is not, present to Sense. Consciousness is admitted to be the only ground of certitude. All Sensation is certain, indisputable.* The test and measure of certitude is therefore in Sen- sation. To have a feeling is to be incapable of doubt- ing it. The only possible opening for doubt is not respecting the feeling itself, but respecting some inference connected with it. When I say "I see an apple there," I express an indisputable fact of feeling in terms which imply disputable inferences. The fact is that I am affected mow in a way similar to that in which I was formerly affected when certain coloured shapes excited my retina ; and this affection reinstates the feelings which accompanied it on those occasions ; the whole group of feelings being named apple, I say " there is an apple." The inference may be erroneous ; * " Sonnenklar 1st nur das Sinnliche, nur wo die Sinnlichkeit, anfangt hort aller Zweifel und Streit auf. Das Geheimniss des uninittelbaren Wissens 1st die Sinnlichkeit. v FEUEEBACH : Grundsatzen der Philos, der ZuTcunft. VOL. I. B 258 PKOBLEMS OF LIFE A>T) MIXD. on proceeding to verify it by reducing it to sensible experiences I find that the coloured object is not an apple, i.e., has not the taste, fragrance, &c., which are elements in that complex perception ; the colour and form which led to the inference are found to belong to a marble or wooden body; or to some other fruit resem- bling the apple in some respects, differing in others. 31. With Inference begins error. Since in a simple case of direct Perception we are liable to err, it is intelligible how great must be the liability in more complex mental operations. If Perception is mental vision, in which the unapparent sensibles are rendered apparent, if it is an act of Judgment involving the assumption of homogeneity which everywhere under- lies Judgment* and if there is even here need of Verification, this is obviously still more urgent in Eatiocination, i.e., that process of mental vision in which ideas are reinstated in their sensible series, and the relations of things are substituted for the things themselves. A chain of reasoning however involved is nothing but a series of inferences, i.e., ideal presenta- tions of objects not actually present to Sense. Could we realise all the links in this chain, by reducing con- ceptions to perceptions, and perceptions to sensibles and this would be effected by placing the corresponding objects in their actual order as a sensible series our most abstract reasoning would cease to be anything but a succession of sensations. In astronomical pheno- mena we really see nothing but the directions, simul- taneous and successive, according to which the mind constructs the form of the motion which the eye cannot embrace. In biological phenomena from a few * Compare RULE X. THE LIMITATIONS OF KNOWLEDGE. 250 data we construct a scheme ; and tins scheme, say that of the evolution of an embryo, represents to the mind the successive stages which might as easily be pre- sented to the eye, by a series of embryos at different epochs of development. The only test we have of the validity of our scheme is to translate ideas into sensa- tions. Any point which may be doubtful is tested by ascertaining its sensible basis. We have mentally arranged the facts in one order, assuming that to be the order in which we should see them ; and we pro- nounce this mental order inexact when we find that what is inferred does not correspond with what is seen. Correct reasoning is simply the ideal assemblage of reals. Bad reasoning results from overlooking either some of the reals, or some of their relations. Thus the timid traveller sees a highwayman, where his calmer companion sees only a sign-post in the evening light. Both infer the existence of objects, which if they could be presented in all sensible relations would affect them as a highwayman in the one case, a sign-post in the other. Which inference is correct t Only reduction to Sensation can decide. This reduction effected, the timid traveller finds that he has allowed emotional suggestions to fill up the gap of unapparent details, and from these has constructed his erroneous vision of a highwayman. THE EXTRA-SENSIBLE WORLD. 32. It is by the aid of Inference that we generalise. Since we have positive proof that the Sensible World comprises only a portion, and an insignificant portion of Existence, we must ascertain how the vast outlying province of the Invisible can be accessible, and how 260 PROBLEMS OF LIFE AXD MOD. we reconcile our knowledge of it with the principle of a sensible origin. It has been shown that even our Sensible World, though resting mainly on Sense, and though all cer- tainty respecting it is the immediateness of Sensation, also rests on Inference which is mediate Sensation; since there can be no Perception of an object nothing but vague Feeling unless with present sensations there are linked other sensations in ideal reproduc- tion. In like manner the Extra - sensible World, though resting mainly on Inference, or ideal presenta- tion of reals absent from Sense, necessarily implies the presence of a sensible basis. What is now ideal repro- duction, was once real production ; what is now me- diate was once immediate. But and here lies the point of intersection between perception of the Sen- sible and perception of the Extra-sensible the repro- duction is never a mere repetition, it is always and necessarily somewhat different from the original pro- duction. The neural units in the two cases are never precisely the same : an image is always quantitatively different from its sensation. When we are said to per- ceive an existence, or conceive a process, lying beyond the range of actual presentation, one therefore which never could have been given to Sense, the only test of accuracy open to us, the only mark by which it can be discriminated from a mere illusion, phantasy, or illo- gical conclusion, is the demonstration of its rigorous correspondence with sensible experience. 33. That there is a knowledge of the Extra-sensible, a mental vision of the sensibly Invisible, admits of "to dispute ; the only hesitation permissible is respect- ing its validity. We do not actually experience THE LIMITATIONS OF KNOWLEDGE. 261 through Feeling a tithe of what we firmly believe, and can demonstrate to Intuition. This Invisible is like the snow at the North Pole ; no human eye has beheld it, but the mind is assured of its existence ; and is more- over convinced that, if the snow exists there, it has the properties found elsewhere. Nor is the Invisible con- fined to objects which have never been presented to Sense, although they may be presented on some future occasion it also comprises objects beyond even this possible range, beyond all practicable extension of Sense. It presents objects to the mind's eye such as no bodily eye could discern : molecules, and waves, having their precise measurements and laws, planets and their stages of evolution before man was.* Only one condition is affixed to the inclusion of this region within the circle of Science, namely, that the objects be in such rigorous agreement with sensibles as to be presentable to Intuition with a certainty almost equiva- lent to that of Sensation. The limit of mental vision is the limit of verification. And what is that ? It is the reduction of Inference to Sensation, or to Intui- tion. This reduction may be direct, or indirect, the final guarantee is the same. We measure the distances and calculate the masses of the heavenly bodies, not indeed with a footrule and balance, yet the footrule and balance are our guarantees. We infer the existence * " Indeed the domain of the senses in Nature is almost infinitely small in comparison with* the vast region accessible, to thought which lies beyond them. From a few observations of a comet when it comes within the range of his telescope, an astronomer can calculate its path in regions which no telescope can reach ; and in like manner, by means of data furnished in the narrow world of the senses, we make ourselves at home in other and wider worlds, which can be traversed by the intellect alone." TYNDALL : Rede Lecture on Radiant Heat. 262 PROBLEMS OF LIFE AND MIND. of sodium in the atmosphere of the sun; we cannot see, or handle it, but we know it is there, with a cer- tainty based on grounds similar to those on which we believe in its presence in our laboratories, namely, by its reactions. 34. Whenever an Inference is in agreement with the positive data of Sense, whenever the Invisible is only an extension of the Visible, we pronounce it rationally certain. There is indeed an assumption here of perfect homogeneity in the two cases. But this assumption lies at the root of all induction, all generalisation. It is on this that Mathematics founds its superior exact- ness. After calculating a sufficient number of the terms of a series to have seized its law, we do not re- quire to repeat the calculations for all the succeeding terms, but having found that when the law holds for any one term it holds for the next, we have proved it to be general. Such dispensing with calculation is only justifiable, however, on the assumption that the law is universal ; and since there is always a possibility that the law will change after a certain number of terms, we have to guard against that possibility whenever the result is important. So long as the Invisible reveals by its functions that it is strictly in accordance with the Visible, we can deal with it in confidence, and veri- fication is open to us ; when this boundary is passed, we are helpless. In other words, since all Knowledge is the extension of Experience, bringing what was un- known under the rubric of the known, whenever the Extra-sensible is disengaged from conformity with the Sensible, it is no longer an object of Knowledge, but remains metempirical until the conformity can in any way be established. Just as the base line, when accu- THE LIMITATIONS OF KNOWLEDGE. 263 rately measured, gives the indirect yet accurate measure of the otherwise inaccessible side of the triangle, to know the one involving a knowledge of the other, so the phenomenon presented to Sense gives the accurate though indirect measure of its equivalent beyond Sense. 35. The objects of this Extra-sensible World with which Science is chiefly occupied are the objects either of Inference or Abstraction. Since the inference is only a reproduction of sensations formerly felt, or the extension of such to some new yet similar case, its validity can never surpass that of the original experi- ence ; and since the abstraction is a reproduction, in an abridgment, of concrete experiences, its value must always be determined by those concretes. Thus, whe- ther we are dealing with extra-sensible concretes, such as ether, or vibrations, or molecules ; or with abstrac- tions, such as Mind, or Cause, or Force, the process of Verification is equivalent to that with which we prove the reality of a perceived object. To prove that my perception of an apple is no illusion, I have simply to reduce the inferences involved in the perception to their sensibles : the sweetness, fragrance, solidity, &c., which I do not now feel, but infer, are then transformed from inferences into sensations. To prove that my concep- tions of an Ether and its vibrations are representatives of objective reals, though more laborious as an effort, is similar as a procedure : the inferences on which the conceptions are founded, the inductions through which the conclusion is reached, must severally be re- duced directly or indirectly to sensations or intuitions; that is to say, either to sensibles or to inductions already established on a sensible basis. An inference, once verified, becomes equally valid with a sensation. It is 264 PROBLEMS OF LIFE AND MIND. henceforward a logical unit ; a standard by which we can compare reals and relations otherwise inaccessible. To know that one thing is heavier than another, we need only lift the one after the other at intervals suf- ficiently brief for memory to retain the sensible im- pressions ; to know how much the one is heavier than another cannot thus be determined : we need a mea- sure ; and this involves the inference that if one thing contains the measure more times than the other it will be so much the heavier : an inference which is an in- tuition and has been verified. 36. These brief indications suffice to show both the vastness and the limitations of the Extra-sensible, the sweep of possible Science, and the conditions under which the imagination may display its energy. After such an exposition, it will be idle to object to the doc- trine of the sensible limitations of knowledge, on the ground that the greater part of the objects known never were, never could be presented directly to Sense. In a future chapter on the Ideal Constructions of Science this will be more amply carried out ; and the reconciliation between the experiential and the d priori schools will be effected, in as far as it can be effected by the exhibition of their common ground. THE SUPRA-SENSIBLE WORLD. 37. The two divisions of Existence which have just been considered comprise all that is accessible to Expe- rience, and consequently all that is admissible in Science. There is, however, a third division claimed by Theology and Metempirics, the region of the Supra-sensible, or Metempirical, which is closed indeed against the Method THE LIMITATIONS OF KNOWLEDGE. 265 of Science, but is open to Faith and Intellectual Intuition. Thinkers who believe in such a world of possible know- ledge will reject with scorn the inadequate exposition of the genesis and limitation of knowledge set forth in these pages. They hold the soul to be equipped with powers radically independent of any excitation through Sense, anterior even to the very existence of the or- ganism, and exercised on materials that were never given in feeling.""" By these powers the soul is said to penetrate far beyond the range of the Sensible and Extra- sensible, and is brought face to face with ultimate Ex- istence, the ground of all Eeality. So far from this Invisible World being interpretable by the laws of the Visible, it needs a higher reach of Intuition, and Methods of its own. Schelling in the preface to his work Vom Icli scornfully admits that systems which only hover ; twixt heaven and earth without the courage to push onwards to the ultimate goal are less liable to error, but he prefers the system which taking a bolder flight will either have the whole truth or none. 38. Even those who refuse to accept the special or- gan which Schelling calls the Intellectual Intuition, are forced to accept its equivalent, when they maintain the possibility of metempirical knowledge. "Whether called Reason, Fundamental Ideas, Innate Ideas, or Forms of Thought, its one characteristic is that it is an organ of the soul having no community with the organs of Experience ; and its products are therefore not amen- able to the canons of Experience. " Transcendental Philosophy," says Schelling, meaning the only true Phi- * JACOBI : WerJce, ii. 59. " Wie es eine sinnliche Anschauung giebt eine Anschauung durch den Sinn, so giebt es eine rationale Anschauung durch die Vernunft." 266 PROBLEMS OF LIFE AND MIND. losophy, *' must always be accompanied by the Intellec- tual Intuition ; all the presupposed incomprehensibility of such philosophising rests on no incomprehensibility of the ideas themselves, but on the absence of the requisite organ to grasp them. Without this Intuition there is no substratum to support this Philosophising. It is what Space is to Geometry." * He declares the Tran- scendental Philosophy to be like Geometry a science constructed from postulates. But he overlooks the distinction that Geometry is, and his Transcendental Philosophy is not, constructed from sensible postulates, and is thereby applicable to sensible experience. Metempirical speculators cheerfully admit the claims of Science within its own sphere, and admit that there the inaccessible lines can only be measured by the assumed correspondence with lines that are accessible. But they affirm that in Theology and Metaphysics such a procedure is fallacious, because the problems lie wholly beyond the range of Science, and therefore require other Methods. This is paralleled by the inventors of perpetual motion who admit that in all machines hitherto constructed the law is absolute which says " what is gained in force must necessarily be lost in velocity ; " but this does not deter them from attempt- ing to construct a machine which shall escape the law. They are confident that their sagacity will detect some unknown resource which will extricate the machine from the tyranny of mechanical laws ; and as Carnot well says, " Us se croient d'autant plus surs de la ren- contrer qu'ils s'eloignent davantage de tout ce qui paroit avoir de la relation avec les machines usite'es, parcequ'ils s'imaginent que la the'orie e'tablie pour celles * Trans. Idealismus, p. 51. THE LIMITATIONS 07 KNOWLEDGE. 267 ci, ne pent s'e"tendre a des constructions qui leur sem- blent n'y avoir aucun rapport. " * 39, Whatcan.be said to such speculators? Kefu- tation is impossible. They deny the validity of our tests, the applicability of our Methods. To the inven- tor of a perpetuum mobile the mechanician says : " Produce it, and you will prove our arguments erro- neous ; but till you have produced perpetual motion we shall continue to hold the attempt chimerical." To the metempirical speculator we may say : " All Expe- rience is against you ; yet if you have any means of proving the existence of an organ which grasps realities beyond those given through sensible Experience we shall admit our error ; but till this is proved, we must hold your efforts to be misdirected." t 40. There is one thing, however, which is not per- mitted to the metempirical speculator, even on the largest allowance of liberty of speculation, and that is, to control by his results the results of empirical re- search, to interpret the positive or speculative teach- ings of scientific inquiry by doctrines framed on the metempirical Method. If we grant the existence of a Supra-sensible possible to be known, and admit that it is wholly distinct from the Sensible World, we must insist on the two never being confounded ; whereas if they are identical they must never be separated. Thus is the Supra-sensible wholly excluded from the field of * CAENOT : Principes Fondamentaux de VEquilibre et du Mouvement. 1803 ; preface, xviii. t SCHELLING places us out of court by declaring that "whoever has not the Intellectual Intuition knows not what it is, understands not what is said of it. A negative condition of its possession is the clear and inner vision into the nothingness of all Unite knowledge. . . . As to the pretended fluctuations in Philosophy they are merely the appearances of change to ignorant minds." Vorlesungen uber die Methode, p. 96. 268 PROBLEMS OF LIFE AND MIND. Research. Whatever conclusions Speculation may reach respecting Existence lying beyond the sphere of sensible phenomena, must be kept in that outlying region. If they are brought into the sphere of pheno- mena, they become amenable to the canons of sensible Experience. 41. Here the reader sees the application of Rule III. adopted from Newton.* He is requested to pon- der that Rule and to compare the criticism of a cele- brated metaphysician, Herbart; a criticism all the more remarkable because Herbart claims to found Metaphysics on a scientific basis. After quoting pas- sages from Haiiy and Biot which are only different expressions of Newton's Rule, he remarks : " We are then to collect and to connect facts as far as possible, and to keep our eyes open that we be not taken by surprise when facts present themselves. Perception must so far precede Thought that both may stand in assured harmony. We have also to ignore all assump- tions and forced interpretations. Well and good. Thus far there is no dispute. But I venture to go further and remark that this method ignores an essen- tial element, namely, that Thought must not only harmonise with Perception, but also with itself." t Now this element, which is said to be ignored in * Which has also been casually expressed by DESCARTES, who, however, frequently violated it in his own speculations : " Nee puto quemquam ratione utentem negaturum, quin longe melius sit, ad exemplum eorum quae in magnis corporibus accidere sensu percipimus, judicare de iis quae accidunt in minutis corpusculis, ob solam suam parvitatem sensum effugi- entibus, quam ad ha3C explicanda, novas res nescio quas, nullam cum iis quae sentiuntur similitudinem habentes excogitare." Princijna, iv. ccL t " Das Denken soil nicht bloss mit dem Anschauen, sondern auch mit sich selbst ubereinstimmen." HEEBABT: AllgemeineMetaphysik; Werke, iv. 12. THE LIMITATIONS OF KNOWLEDGE. 269 Newton's Eule, and which would indeed be a fatal omission, is really there in the only meaning of it which has a justification, but is not there in the meaning which it may easily be made to bear, and which is the latent poison of all metempirical specula- tion, namely, the release of Thought from the control of sensible verification. All that Herbart says in his exposition of Method will be accepted by the positive thinker; who will, however, add that the phrase "har- mony of Thought with itself " has positive value only when interpreted as the harmony of one induction with another, and the harmony of inference with sensation. A bank-note is only money when convertible into gold, which in turn is convertible into goods ; so long as the pecunia really represents the pecus, there is no need to drive actual cattle into the market ; the transference of the money being equivalent to the transference of the cattle which the money will buy. The mistake of the speculative thinker is that he is too apt to interpret the " harmony of Thought with itself" in a more inde- pendent way. He is satisfied with a logical harmony ; if no logical contradiction presents itself, he relies on there being a corresponding order in things. The note for twenty pounds of which he makes entry in his ledger may have been issued from an insolvent bank, or may be a forgery, and its worthlessness will never appear in his ledger, but only when an attempt is made to convert it into gold or goods ; the induction which took its logical position in his speculation could only be proved worthless by objective verification. Thus there is no logical contradiction in the existence of a spirit- world in all its features entirely unlike the sensible world. We cannot say that such a world is 270 PKOBLEMS OF LIFE AND MIXD. impossible ; we can only say, that, if it exist, it is to us inaccessible, because to become accessible it must pass into the sphere of the Sensible, and in the passage will cease toV I8ia>v dd d\r)8t)s, KOI naa-iv vndpxft TOIS fwotf. SiavofHrdai S'eVS/xerat Kat tyfvftws, KOI ovdfvl vrrdp^ft ^> (JLTJ Kal \6yos. De, Anima, lib. III. c. iii. 20. THE LIMITATIONS OF KNOWLEDGE. 289 of existence which never were, and never could be, real; and are very often at variance with sensible Experience. It not only deals with data that are extra- sensible, but with data avowedly fictitious. The point, the line, and the circle are abstractions ; they are ele- ments of ideal, not of sensible space. Nevertheless out of these abstractions a science is constructed which is rigorously exact in itself, and is found to harmonise with that very Experience which it appears to contra- dict. In the presence of such a fact the question may well arise : How can such abstractions have a positive value, an objective validity, yet metempirical abstrac- tions be rejected ? or to put it in Berkeley's way Why do you trust the mathematician, and distrust the theo- logian \ The answer to this question must be post- poned till we have examined more closely the proce- dure of Science, and recognised its essentially ideal con- struction out of real experience. 62. I say ideal construction, and emphasise it, with the intention of meeting the vulgar objection, iterated from all sides, against the Experiential Method, whose followers are said ' to believe only in what they can see and touch ; ' whereas the truth is that Science mounts on the wings of Imagination into regions of the Invis- ible and Impalpable, peopling these regions with Fictions more remote from fact than the phantasies of the Arabian Nights are from the daily occurrences in Oxford Street. The fictions of the thinker differ from the fictions of the poet in not being wayward caprices ; they are constructed in obedience to rigorous canons, and moulded by the pressures of Reality ; two conditions absent in the fictions both of Fairyland and of Metem- pirics. It is worthy of remark that the two regions of VOL. I. T 290 PROBLEMS OF LIFE AND MIND. indisputable certainty are the extremes of the mental world Sensation and Abstraction. There is no doubt possible in Sensation, whatever doubt may hover round Inference from it. There is no doubt possible in Ab- straction, whatever doubt may hover round its con- crete reality. The intermediate region of Inference is the sphere of doubt.* 63. Now inferences are hypotheses; and these be- come less and less doubtful in the exact proportion of their reduction to Intuition or Sensation. We shall presently see the part played by Hypothesis ; here let us be content with the significant fact that Science is so truly ideal, without pretence of reflecting real exis- tence, that it avowedly relies on data known not to be true, except within its own sphere of Abstraction.t Note, however, this essential point : the abstraction must not have been arbitrarily formed if it is to be subsequently applied to reality : it must have been formed from concretes (by the substitution of ideal limits for sensibles) ; and this condition having been fulfilled, the sensible concretes, which are its elements, * " Les notions les plus abstraites, celles que le commun des hommes regarde comme les plus inaccessibles, sont souvent celles qui portent avec elles la plus grande lumiere : I'obscurit^ semble s'emparer de nos idees a mesure que nous examinons dans un objet plus de proprietes sensibles ; 1'iinp^netrabilite', ajout^e & 1'idee de 1'etendue senable nous offrir un inystere de plus ; la nature du inouvement est une enigme pour les phi- losophes ; en un mot plus ils approfondissent 1'id^e qu'ils se forment de la matiere plus cette idee s'obscurcit et paroit vouloir leur dchapper ; plus ils se persuadent que 1'existence des objets ext^rieurs appuy^e sur le temoignage equivoque de nos sens esfr ce que nous connaissons le moins imparfaitement en eux." D'AxEMBERT : Traite de Dynamique, 1796, p. ii. t " II importe peu aux geometres qu'il existe physiquement une sphere parfaite, un plan parfait ; ces figures ne sont que les limites intdlectuelks des grandeurs materielles qu'ils considerent." MONTUCLA : Hist, des Maihematiques, i. 27. THE LIMITATIONS OF KNOWLEDGE. 291 not having been capriciously introduced, we may be certain that the abstraction is as true in its sphere,- as the sensibles were in theirs. A ratio once abstracted, from numbers is as true as the numbers from which it was abstracted. In this way an abstraction becomes a truth of Nature, though departing from the phenomena of Nature by its disregard of details. 64. The first law of Motion is an absolute truth. But the supposition that any real body will pursue an uniform movement in a straight line, is flagrantly at variance with all observation, and with what is even physically possible. No such phenomenon was ever seen. No such phenomenon could present itself in an universe like ours, where Motion is always accelerated or retarded, and always more or less divergent from a straight line. The ideal law is absolute within ideal space : it is the identical proposition that no change in velocity or direction can occur unless the factors of such a change are operant. But within real space the requisite conditions are unrealisable : the presence of other bodies in movement must always obstruct the realisation of the conditions : the factors of a change are always present. 65. There is a real law of Motion, one to which all movements conform without variation ; it may be ex- pressed in the formula : Motion always pursues the line of least resistance. This formula has the utmost generality. It does not formulate the process as if Motion were necessarily rectilinear; that is quite an arbitrary assumption, and is open to Comte's criti- cism ; * but it says that whatever the direction im- * " A I'origine du mouvement il est clair que la trajectoire du corps n'a point encore de caractere geometrique determine, et que c'est seulement 292 PROBLEMS OF LIFE AND MIND. pressed, that, and that only, will be preserved, until another impress modify it.* 66. The ideal law sets aside all resistances. From the Pisgah of what is, the mind sees what witt be, or what would be, if all conflicting movements were allowed to neutralise each other. Laws are indeed nothing but general formulae expressing general facts from which all disturbing particulars are eliminated. They do not describe the path which bodies actually pursue, but the path the bodies tend to take, and would take were the obstacles removed. Thus, to cite the law of the tides there never is, in fact, sufficient time for the sea to assume the form towards which it tends, and which it would assume were the period longer ; the mathematician disregards this fact, and substitutes his ideal law in its place. If, on this principle, a woman were to argue that her hunchback lover had a form of graceful symmetry, because his back would be straight were there no curvature of the spine, we should point out that she confounded the concrete with the abstract, the real with the ideal. In like manner were any one to declare the law of the tides to be false, because the observed facts did not conform to it, we should point apres qne le corps a parcouru un certain espace qu'on peut constater quelle ligne il decrit. II est evident par la geometric que le mouvement initial au lieu d'etre regarde comme rectiligne pourrait etre indifferemment suppose circulaire, parabolique, ou suivant toute antre ligne tangente & la trajectoire effective, en sorte que la meme argumentation repetee pour chacune de ces lignes conduirait a une conclusion absolument indeter- minee." COMTE : Philosophic Positive, L 558. * Compare the celebrated "principle of least action" formulated by MAUPEKTIUS : " La trajectoire d'un corps soumis a 1'action de forces quel- conques devait necessairement etre telle que Tint^grale du produit de la vitesse du mobile par 1'element de la courbe decrete fut toujours un mini- mum, rektivement a sa valeur dans toute autre courbe." THE LIMITATIONS OF KNOWLEDGE. 293 out that laws being ideal constructions are not tran- scripts of real particulars. 67. Again : the path of a planet is said to be an ellipse. Every one knows that the real orbit is nothing of the kind. The ellipse is not to be found in the heavens but in the calculations of astronomers. The path would be elliptical if there were only one planet moving round the sun ; but as, in fact, there are many planets, all acting on each other by forces varying with their varying positions, the planets cannot move in exact ellipses, the radius vector of each does not pass over equal areas in equal times. The orbit is not only not an ellipse, it is not any regularly formed curve ; nor is the same curve described in successive revolutions. Are then Kepler's laws illusions "? By no means : they are abstractions ; they are Types erected by scien- tific Imagination, which moulds the elements of concrete observation into abstractions by getting rid of all per- turbing particulars. The planet is supposed to move in an ellipse, by assuming the elements of the ellipse to have been perpetually altering. The supposition is a fiction, and is justified by its results. The reader sees at once that by similar fictions Ptolemy and his successors represented the movements of the planets, adding epicycle on cycle to make theory approximate to observation.* * " Pour representer le mouvement de la planete les astronomes imaginent un astre fictif qui se raeut circulairement autour du soleil dans le plan de 1'orbite ; qui part du pe"rihelie au meme instant que la planete, et dont la distance angulaire a ce point est toujours egale au premier terme nt de la valeur v. Le rayon vecteur de cet astre se meut uniformement et fait a chaque instant avec celui de la planete un angle egal a 2 e. sin. nt. Cet angle variable s'appelle I 'equation du centre. 294 PROBLEMS OF LIFE AND MIND. Sir John Herschel reminds us that Kepler's laws are to be regarded as only first approximations to the much more complicated ones which actually prevail, and that " to bring the remote observations into rigor- ous and mathematical accordance with each other, and at the same time retain the extremely convenient nomenclature and relations of the elliptic system, it becomes necessary to modify to a certain extent -our verbal expression of the laws, and to regard the nu- merical data or elliptic elements of the orbits as not absolutely permanent, but subject to a series of slow and almost imperceptible changes. These changes may be neglected when we consider only a few revolutions ; but going on from century to century and continually accumulating, they at length produce material de- partures in the orbits from their original state."' 68. Another fiction is that by which solids are dis- tinguished from fluids ; it assigns to the molecules of fluids an independence as respects cohesion, enabling them to move freely among each other. This is need- ful for calculation, though obviously untrue in reality, many of the observed phenomena of fluids being due to the cohesion of their molecules, a cohesion less energetic but similar in kind to that in solids; and this fact occasions many discrepancies between theory and practice, notably in the flow of liquids from an orifice. Indeed it is perfectly well understood that all the applications of theory to practice are only approxi- Lorsque Tangle v est egal a deux ou a quatre angles droits, les deux angles v et nt sont egaux ; par consequent 1'astre fictif passe a I'aphfSlie et revient au p^rihelie" en meme temps que la planete ; mais dans la premiere moitie de la revolution la planete precede 1'astre, et dans la seconde 1'astre precede la planete." POISSON : Traitt de Hecanique, 1811, i. 369. * HERSCHEL : Astronomy, Art. 480. THE LIMITATIONS OF KNOWLEDGE. 295 mations. " Take for instance the very simple case of a crowbar employed to move a heavy mass. The ac- curate mathematical investigation of the action would involve the simultaneous treatment of the motions of every part of bar, fulcrum, and mass raised ; and from our almost complete ignorance of the nature of matter and molecular forces, it is clear that such a treatment of the problem is impossible. It is a result of observa- tion that the particles of the bar, fulcrum, and mass separately, retain throughout ;the process nearly the same relative positions. Hence the idea of solving, instead of the above impossible problem, another in reality quite different, but while infinitely simpler ob- viously leading to nearly the same results as the former. The new form is given at once by the experi- mental result of the trial. Imagine the masses in- volved to be perfectly rigid (i.e., incapable of changing their form or dimensions) and the infinite series of forces really acting may be left out of consideration ; HO that the mathematical investigation deals with a G? iinite (and generally small) number of forces instead of a practically infinite number." * 69. Were the whole circle of the sciences to pass be- fore us each would in turn display the essentially ideal nature of its construction, and wide departure from reality, either in its abstractions or in its hypotheses. The abstractions necessarily disregard particulars. The j aws usually accepted as absolutely exact (and justly so in the region of Abstraction), are " only general truths always more or less falsified in every particular case." t * THOMSON and TAIT : Natural Philosophy, 1867, i. 337. t "Seulement des ve'rites generates toujours plus ou moins fausse'es 296 PROBLEMS OF LIFE AND MIND. The hypotheses are fictions, provisional guesses. So far from Facts, Perceptions, constituting the material of Science, as is often said or implied, they are simply the elements out of which its material is constructed. Perception gives the naked fact of Sense, isolated, un- connected, merely juxtaposed with other facts, and without far-reaching significance. To the brute sim- plicity of Sensation must be added the artifice of Con- struction. Science looks through the brute fact, to contemplate the Abstraction which gives it connection, significance. Hence the paradox that we understand the fall of bodies only through the movements of the planets ; the growth of a plant only through biological laws. It is through the manifold ideal constructions of the Possible that we learn to appreciate the Actual. Facts are mere letters which have their meaning only in the words they form ; and these words again have their meaning, not in themselves alone but in their positions in the sentence. The point here insisted on has always been familiar to philosophers in each particular case, but I am not aware of any philosopher having boldly generalised the observation, and proclaimed the introduction of Fiction to be a necessary procedure of Research. The dread lest the admission of Fiction should throw doubt over the certainty of the conclusions reached by its aid, may probably have prevented the generalisation ; especially when no sharp distinction had been drawn between the fictions of Science and the fictions of Poetry. But per- haps the most deterrent influence has been due to the erroneous conception, almost universal, of the phe- dans chaque cas particulier." JAMIN : Court de Physique de FEcole Polytbchnique, i. 28. THE LIMITATIONS OF KNOWLEDGE. 297 nomena of Nature being determined by Law. This must be replaced by the more accurate conception of the Law being determined by the phenomena. What we call Laws of Nature are not objective existences, but subjective abstractions formulae in which the mul- tifarious phenomena are stripped of their variety and reduced to unity. 70. Before proceeding to give precision to this per- haps paradoxical view of Law, we may pursue the illustration of the scientific employment of Fiction, especially in the creation of Abstract Types. It has already been shown that the first law of Motion is no expression of the actual movements, but simply the ideal standard by which all movements may be measured. The mathematician knows that when a point moves along a curve there is inaccuracy in saying that it moves in any one direction through any arc however small. But a straight line may be found at every point which more nearly than any other straight line repre- sents the direction of the motion. In the same way no motion can be uniform, no velocity can be uniform, but we can at every instant assign an uniform velocity which shall more nearly than any other represent the rate at which the body is moving. This is obviously an ideal construction, not a real transcription. Assuming that if there were no force traversing the direction of a body, then the body would proceed in a straight line, we are enabled to estimate the forces in any deviation from that straight line. Eectilinear Motion, though never possible, is thus the ideal Type to which all actual motions are ideally made to conform. We must regard it purely in abstraction the ideal 298 PROBLEMS OF LIFE AND MIND. limit replacing the real limit otherwise the law is false.* 71. Schelling well sayst that " the necessary tendency of all Science is to pass from Nature to Intelligence. The highest perfection of research would be the thorough spiritualisation of natural laws, reducing them to laws of Intuition and Thought. The material phenomena must give place to their laws. Optical phenomena are nothing but a geometry whose lines are drawn by light ; and this light itself is of dubious mate- riality." It may not at first be apparent why, since we have always to deal with concretes, we must always transform them into abstractions ; why, having to understand the phenomena presented to Sense, we effect this through Laws that are intelligible but not sensible. An exami- nation, however, of the conditions of Knowledge dis- closes that Science differs from Sensation in being in- direct and constructive that Abstraction is a primary condition of Perception that Inference, or hypothesis, is largely mingled in what seems simple sensible ex- perience. Thus it appears that among the preliminaries of exact knowledge there are two which have the para- doxical aspect of looking away from the data directly presented, and of guessing the presence of other data looking away from the particular object, to find some general object which includes this particular one with- * " La direction d'une force est celle de la ligne suivant laquelle le point se mouvrait en vertu deson action, s'il etait entierement libre." DUHAMEL : Mecanique, i. 28. But as the point never is entirely free, the straight line is imaginary. Nevertheless, the admirable artifice which resolves all forces into two, and gives their resultant as the diagonal of the parallelogram, formed by these components, presents the Calculus with a straight line never presented in Nature. t SCHELLING : Transcend. Idealismw, p. 3. THE LIMITATIONS OF KNOWLEDGE. 299 out including its individual characters, seeking Man in Socrates and the Eodent in this rabbit. Instead, there- fore, of vaguely warning Philosophy against the dangers of Abstraction and Hypothesis real as these dangers are we should openly avow them to be indispensable aids, and, by a clear recognition of the aid they furnish, learn wherein their dangers lurk. 72. Let us glance at one or two transcendental con- ceptions, and note the value of a purely imaginary Type. And first of the conception by which the great poet Goethe illuminated the whole of Vegetal Morpho- logy, one of those germinal conceptions which change the state of a science. Amid all the diversities of sensible experience he saw the typical form of the Leaf present in every organ of the Plant, and conceived the Plant itself to be only a variously transformed Leaf, a Type which, developed in spirals in the stem, was also developed or aborted in calyx, stamen, and pistil, but always under every variety presenting constant rela- tions, and preserving one typical order. Schiller's ob- jection, which irritated him so much, that the Leaf was an idea, though true enough in fact, was irrelevant as an objection. The Leaf was an idea, but an idea which had sensibles for its concrete elements. A similar conception was applied by Goethe to the skeleton of vertebrates ; and, in the hands of his successors, the Vertebral Type has been a potent instrument of mor- phological research. Of the same order is the concep- tion of the Animal Series, first suggested by Aristotle, but brought into effective clearness by Lamarck, Geoffroy St Hilaire, and still more luminously by Mr Darwin. 73. It is, however, a profound mistake in regard to Nature, and no less in regard to Method, when such 300 PROBLEMS OF LIFE AlfD MIND. Types are wrested from their position among Ideals, and offered as Reals. There is not in Nature, there never was, a typical Lea a primitive Vertebra, or an existent Series, from which all plants, vertebrae, and animals have successively varied. There never was a Plan laid down, according to which the organic world was constructed, after the manner of a plan pre-arranged by an architect for the builder's guidance. On the con- trary, this Plan, and these Types, are our after-thoughts, abstractions formed out of the sensible data presented by various plants, vertebrae, and animals; they are ideal constructions from reals, obtained by the mind's group- ing together the dominant resemblances, and setting aside all the many diversities. The theologian and metaphysician, by a procedure familiar to them, seize hold of these Types, and present them as indices of a Plan in Creation. But this is the ixrrepov irporepov fallacy of supposing a resultant to have been the deter- minant. All that Experience warrants is the assertion that the original protoplasm, which was wholly destitute of plant-form, leaf or other, and the germinal membrane equally destitute of vertebral form, did, in the succes- sive stages of evolution, pass through many forms, each new form being determined by that which preceded it, and by the external pressures of the medium in which it was evolved ; consequently, in so far as these external influences had a general resemblance, the resultant forms were necessarily similar. The Type is an ab- stract expression of this general similarity. Such is the positive doctrine of Morphology. The speculative doctrine which finds favour with theologians and metaphysicians teaches that the Type pre-existed THE LIMITATIONS OF KNOWLEDGE. 301 in the Divine Mind, or at any rate in Nature; or teaches that somewhere there was a vertebra formed, and from this vertebra all the other bones were constructed by modification of its special parts, and so the skull was a modification of the spinal column, &c* 74. The scientific value of Types is that of being ideal guides, not real facts. They are standards by which deviations may be appreciated. It is because so few writers, even of those who adopt the Evolution Hypothesis, remember that it is only an hypothesis, and being an Ideal cannot be accepted as a Real, that opponents demand and advocates endeavour to supply evidence of its reality. The Animal Series is an ideal construction. Writers who forget this, not con- tent with the inductive data for a speculative insight, demand and evolutionists endeavour to supply evi- dence which, could it be furnished, would at once transform the hypothesis into a demonstration, the problem into a theorem. Thus one of the commonest objections urged is, that were the hypothesis true we ought to find a gradual and continuous line of organic development, from one group to another, and one spe- * In the following passage Prof. ^!AX MULLER combats an analogous error : " There never was a common uniform Teutonic language ; nor is there any evidence to show that there existed at any time a uniform High- German or Low-German language, from which all High-German and Low-German dialects respectively are derived. All we can say is, that these dialects passed at different times through the same stages of gram- matical growth. We may add that with every century that we go back the convergence of these dialects becomes more and more decided ; but there is no evidence to justify us in admitting the historical reality of one primitive and uniform Low-German language, from which they were all derived. This is a mere creation of grammarians, who cannot under- staid a multiplicity of dialects without a common type." Lectures on the Science of Language, 1871, i. 205. 302 PROBLEMS OF LIFE AND MDsD. cies to another ; whereas, in point of fact, what we do find is group sharply demarcated from group, species separated by an unbridgeable gulf from species ; and these gaps the imagination is baffled in attempting to fill up, so as to render the transition from one form to the other apparent to Sense. The objection is wholly irrelevant; and although one cannot but be grateful for the interesting researches of those zoologists and palaeontologists who endeavour to supply the evidence of 'missing links' grateful because all extensions of our knowledge of organic forms is valuable one cannot applaud them for thus attempting to answer the objec- tion, or for evading it by refuge in our geological igno- rance. The objection is based on a twofold misconcep- tion. Continuity of form in the sense demanded is incompatible with that variety of form which Evolu- tion postulates and Observation discloses. Such con- tinuity would make the whole organic world one form. The Type would cease to be an abstraction, and degen- erate into a concrete sensible. Between any two forms, however similar, short of identity, there must, ex vi termini, be a solution of continuity; if the incident forces which determine the form be unequal, the re- sultant must necessarily be a variation. Thus, suppose we have two samples of protoplasm identical in all re- spects, but subject to forces which vary in some respects, the resultant forms must be separated by a gap which is indefinite. It is an elementary deduction from mechan- ical principles, that when a body susceptible of various positions of stable equilibrium is moved in various di- rections on a plane, the changes from one position to another must be abrupt, without any stable intermedi- THE LIMITATIONS OF KNOWLEDGE. 303 ates. If two forms differ, and they must if they are two, then their difference is a solution of continuity, though it may be accompanied by resemblances. There can be no stable transition between an exogen and an endogen, between an animal with a shell and an animal without a shell, more than between a crystal and its solution, or between sugar and oil, both hydrocarbons. We may regard all sensations as modifications of Sen- sibility, but there is no transition between one sensation and another; and just as Sensibility is the abstract expression for all concrete sensations, and comes into existence with them, so Animal is the abstract expres- sion for all concrete animals. 75. The distinction between Types and Eeals was entirely overlooked in the famous controversy between Cuvier and Geoffroy St Hilaire, and is equally so in the controversy now raging between the opponents and adherents of Darwinism. It will one day be likened to the controversy raised by the first promulgation of the Differential Calculus, the logical basis of which even Leibnitz himself very imperfectly conceived, and which even in our own day is generally acknowledged to be incomprehensible, because, as I hinted before, quan- tities are not discriminated from operations on quan- tity. Leibnitz when pressed by objections declared that he regarded infinitesimals as incomparables* which might be disregarded in reference to finite quantities as grains of sand in reference to the sea ; a defence which Comte remarks completely vitiates the analysis reducing it to a mere calculus of approximation, " Qui sous ce rapport serait radicalement vicieux puisqu'il * LEIBNITZ : Opera, Ed. Dittens., ii 370. 304 PROBLEMS OP LIFE AND MIND. serait impossible de preVoir a quel point les operations successives peuvent grossir ces erreurs premieres, dont 1'accroissement pourrait meme e'videmment devenir ainsi quelconque." * Without pausing here to exhibit the logical justifica- tion, let us ask, how did mathematicians practically justify the new Calculus ? By showing that it enabled them to solve problems hitherto insoluble. In like manner the adherents of the Evolution Hypothesis may answer the objections urged against it by showing and they do show the vast reach of organic pheno- mena, hitherto inexplicable, which are rendered intelli- gible by its aid. This will not prove the hypothesis to be true ; but it proves it to be effective, which is all an hypothesis can pretend to be. Infinitesimals may not exist in Nature ; the Animal Series may have no real correspondent ; but the calculus and the evolution hypothesis are ideal constructions of vast power in scientific research. MORAL TYPES. 76. As a final example let us not omit to mention the creation of Moral Types, the standards for our con- duct in life. It is often made an objection against moral and religious conceptions of Duty that they de- mand for their realisation a perfection which is not human. Certainly no man ever did, or could, realise in conduct the exalted ideal of life which he may have formed, or accepted from others. " Oh, would that for one single day we had lived in this world as we ought ! " is the passionate exclamation of A'Kempis (or whoever wrote the Imitation). It has been most keenly felt by * COMTE : f kilos. Positive, i. 242. THE LIMITATIONS OF KNOWLEDGE. 305 those whose lives have been most free from reproach. The objection to ideals, on the ground of their sur- passing human nature, is a misconception of their function. They are not the laws by which we live, or can live, but the types by which we measure all devia- tions from a perfect life. The mind which has once placed before it an ideal of life has a pole-star by which to steer, although his actual course will be determined by the winds and waves. The pole-star is not the helm, nor is the helm more than one of the active agents. Our passions and our ignorance constantly make us swerve from the path to which the pole-star points ; and thus the ideal of a Christian life, or the ideal of Marriage, are never wholly to be realised, yet who denies that such ideals are very potent influences in every soul that has clearly conceived them ? It is a truth, and not an idle phrase, that man does not live by bread alone ; that it is his privilege to live by aspiration, hope, and love, to be moved by ideal im- pulses which cause him to check the impulses of a lower self, to forego the transient pleasure of Sense, and passionately strive after the nobler pleasures of heart and intellect. We all place before ourselves the ideal of a noble life, the type of a grander character than our infirmities enable us to realise ; and we do not look on that ideal as a fiction, on that type of character as a falsehood, because we fail to realise it. Like the typical laws of physical processes, these conceptions are solid truths although they exist only as ideals ; and he who imagines their validity impugned because human nature can but imperfectly realise them, is as ignorant of Life as he would be who should deny the VOL. i. u 306 PROBLEMS OF LIFE AND MIND. validity of natural Laws, because of the perturbations observable in natural events. The contrast between a real law and an ideal law, such as we find in the second law of Motion (formulated by Galileo in the parallelogram of forces) and the first law, which is only the formula of what would be the motion were all disturbing conditions absent, is equally exhibited in the moral law that "the habit of right action is the securest preparation for acting rightly under emergencies" and the ideal law that "we should love our neighbours as ourselves." No moving body does move uniformly in a straight line ; no man does love his neighbour as himself. All bodies do move in the diagonal of the parallelogram of two incident forces ; and all men are trained to act rightly on emer- gencies by what is a kind of moral instinct, organised in previous habits of acting rightly. 77. It would be of eminent service if a classification of the Laws real and ideal were drawn up, so that in every case there might be distinct understanding whether we were dealing with a Type which pretended to no objective reality, or with a Notation of the real process observed, and only varying from observation as the general varies from the particular. To effect this it would be necessary first to settle the question mooted in the succeeding chapter. CHAPTEE VI. WHAT ARE LAWS OP NATURE ? 78. REFERRING to what was briefly stated in our In- troduction (On the Method of Science, 70 et seq.), we there saw that Law was originally supposed to have not only an objective existence in the phenomena, but an objective existence independent of the phenomena ; and this ancient error is still alive. By one of the illusions into which Philosophy easily glides, a Law of Nature is supposed to hold a position with respect to natural ob- jects which is analogous to that held by a legislative enactment with respect to social life. Laws are a kind of wise police keeping Nature in order. How far the connotations of Language inevitably transfer this con- ception of the regulation of conduct to the regulation of Nature, it may be difficult to say ; but the fact is that having once named Process by the word Law, we have great difficulty in keeping the two conceptions distinct. Even careful writers are apt to express them- selves ambiguously on this point ;* and the majority of * To give a single instance, Archdeacon PRATT in his important treatise TJie Mathematical Principles of Mechanical Philosophy (1836) opens with the following statement : " The uniformity which characterises the operations of nature leads to the conjecture that the phenomena of the material world [not then the phenomena of the spiritual world ?] are regulated by certain fixed laws. Numberless appearances strengthen the 308 PROBLEMS OF LIFE AND MIND. writers assuredly suppose that Law is independent of the phenomena which it rules. Strongly impressed with the mischievous tendency of its suggestions, I was many years ago led to propose the abandonment of the word Law in relation to physical phenomena ; but I soon found that the reform was impracticable; the word is too deeply rooted. Instead, therefore, of attempting to get rid of it, we must be content with a recognition of its misleading connotations, and fix in our minds that Law is only one of two conceptions, 1, a notation of the process observed in the phenomena, which process we mentally detach and generalise by ex- tending it to all similar phenomena ; 2, an abstract Type, which although originally constructed from the observed Process, does nevertheless depart from what is really observed, and substitutes an Ideal Process, constructing what would be the course of the pro- cess were the conditions different from those actually present. 79. The first conception is so far real that it expresses the observed series of positions. It is the process of phenomena, not an agent apart from them, not an agency determining them, but simply the ideal summa- tion of their positions. The story of a man's life is not a theorem which he has to work out, but a story which we elicit from all the events, and exhibit in its lead- ing directions. Phenomena, in as far as they are ruled regulated, determined in this direction rather than in that, and necessarily determined in the direction taken, are determined by no external agent corresponding to Law, but by their co-operant factors internal and suspicion that they are the necessary consequences of some universal principles with which matter has been endowed by the Creator." THE LIMITATIONS OF KNOWLEDGE. 309 external : alter one of these factors, and the product will be differently determined. It is owing to the very general misconception of the nature of Law that there arises the misconception of Necessity ; the fact that events arrive irresistibly when- ever their conditions are present, is confounded with the conception that the events must arrive whether the conditions be present or not, being fatally predeter- mined. Necessity simply says that whatever is is, and will vary with varying conditions. Fatalism says that something must be ; and this something cannot be mo- dified by any modification of the conditions. Every Law has two aspects, one concrete and experi- mental, the other abstract and theoretical. In the ex- perimental department a Law is simply the notation of observed facts ; in the theoretical department this is ex- hibited as the necessary consequence of certain other and more fundamental facts ; and, as Prof. Challis reminds us, "every fact, every law which experiment makes known, is a problem for the theorist to solve by mathe- matical reasoning." Kepler discovered that the radius vector of each planet would describe round the sun equal areas in equal times, were there no perturbing conditions ; and he grouped the observed facts under this Law. Then came Newton, who deduced this Law, not from the observed facts, but from the primary fact of which it was the necessary consequence, namely, the Law that gravitation is a force acting in the line of the attracting and attracted bodies. 80. A Real Law differs from an Ideal Law, or Type, not in being less of a subjective conception, but in being less of a construction not in having an existence inde- pendent of objects and of us, in contradistinction to the 310 PROBLEMS OF LIFE AND MIND. Ideal Law supposed to be entirely our own creation but in expressing more rigorously the results of obser- vation, and being thus reducible to sensible experience. It so far agrees with the Type that it is not any one series of observed positions, but a generalised series an abstract group of resemblances from which differ- ences are rejected. By this generalisation a particular series becomes a general Law, under which all resem- bling phenomena are classed, and the notation is made once and for ever. We are said to have explained any particular fact when we have ranged it under the series to which it belongs, in other words assigned its Law. What is this ? simply the series of positions which each phenomenon occupies under definite conditions. The position is not determined by the series ; the pheno- menon is not coerced by the Law, but each successive position is assumed because that, and no other, is the resultant of the co-operant forces. And when observa- tion discloses a discrepancy between a fact and its Law, do we not at once declare this to be due to some differ- ence in the factors ? do we not preserve the integrity of the Law by invoking the presence of some perturbation? Now this is clearly the substitution of one series for another. Perturbations are mere figments of the mind, cloaks for ignorance, unless we acknowledge them to be positions which we do not observe, and which if ob- served would reveal that this series was not the series expressed in our Law. For in truth the so-called in- violability of Law is absolute only in so far as what- ever is is, and cannot be otherwise. It declares the facts to be unchangeable so long as their factors are unchanged. " Every process," we are told, " has laws known or THE LIMITATIONS OF KNOWLEDGE. 311 unknown, according to which it must take place." I regard this as very inexact or very misleading. The law is the process ; and there is no other must in the case than is involved in the identical proposition that the process must be the process. When comets are said to have laws in obedience to which they return at the times predicted, this obedience is metaphorical; the comets, in fact, sometimes do not "obey" the pre- scribed law, the prediction is falsified because the posi- tions have been different. If it be replied that this only proves our conception of the process to have been inac- curate, and that we neglected in our formula certain elements which were co-operant, this, although perfectly true, only restates the argument that the real law of cometary movement is the series of cometary positions and this must in each case be what it is. 81. But if in this sense the Eeal Law is inviolable because it is simply the expression of what is, and all the so-called perturbations are different Laws, the Ideal Law is of course inviolable because it is abstracted not only from all perturbations but from all real processes. It expresses not what is, but what would be under other conditions. Motion never is uniform, never rec- tilinear ; the stamen or pistil of a plant never is a leaf ; the bones of the skull never are vertebrae ; the planet never does describe an ellipse these and all other Ideal Laws are abstract truths ; and they can only be applied in explanation of concrete facts by a constant rectifica- tion of our natural tendency to mistake abstractions for realities. 82. The distinction here established is not quite the same as that proposed by Mr Mill, who divides laws into Ultimate and Derivative. He assigns inferior im- 312 PROBLEMS OF LIFE AND MIND. portance to the Derivative Laws, and will not allow them to be Laws of Nature. According to the views ex- posed in this chapter the Derivative Laws are those un- derstood as Laws of Nature, while the Ultimate Laws are not Laws of Nature, but subjective constructions having no corresponding objects. Mr Mill holds that the three laws, 1, air has weight ; 2, pressure on a fluid is pro- pagated equally in all directions ; 3, pressure in one direction not opposed by equal pressure in the contrary direction produces motion are three Laws of Nature. I aoree: but cannot follow him when he adds that O ' although from the combination of these Laws we can predict the rise of mercury in the barometer, this last is not a Law of Nature, but simply a derivation from three Laws a case in which all three co-operate. It seems to me that the law of atmospheric gravity is a case of the general law of gravitation, and the law of fluid pressure is not less derivative than that of the rise of mercury in the barometer; the equal propa- gation of the pressure is a fact reducible to factors, .namely, the uniform disposition of the molecules of the fluid and the laws of motion of those molecules. The only Laws that can with strictness be called ulti- mate, in Mr Mill's sense, are those of Number, Position, and Force in the object-world, and those of Sensation and Grouping in the subject-world; all phenomena may be reduced to cases of these Laws. 83. This mode of regarding Laws, namely, as Pro- cesses briefly formulated in their essential characters, and as Types by which Observation may be guided, enables us to escape the fallacy of supposing pheno- mena to be determined by their own resultants. Ideal Laws, or Types, stand somewhat in the rela- THE LIMITATIONS OF KNOWLEDGE. 313 tion to Eeal Laws, or Generalisation, that Hypotheses do to Theories. There can be no doubt respecting their immense service in Eesearch, and yet they wear the paradoxical aspect of assisting Observation by delib- erately neglecting it in favour of Ideal Construction. Before considering the limitations which this employ- ment of Ideal Construction demands, it will be needful here to come to a distinct understanding on the use of hypothesis. CHAPTER VII. THE USE AND ABUSE OF HYPOTHESIS. 84. COULD we observe, the processes of nature we should need no Science to explain them : Perception would suffice. But we cannot observe them, or can observe them only in fragments; we must therefore imagine what we cannot see, and link the fragments into a whole. Explanation of phenomena is always a making visible to the mind's eye of what is invisible in the facts presented : It is the rendering conspicuous of those inconspicuous Relations of coexistence and succession through which one phenomenon co-operates with, and thus determines a change in, another. When this is seen, there is an intuition of the truth that everywliere a recurrence of these Relations, or of similar conditions, must be accompanied by this change, or a similar change. This is the intuition which rests on the assumption of homogeneity (RuLE X.) and is justified by the logical principle of Equi- valence (to be hereafter expounded). 85. Not only does Science pass from the considera- tion of isolated, visible, facts, to their co-ordination and consolidation in general, invisible, facts; but it necessarily tends to generalise more and more, to become more and more abstract, less and less occupied THE LIMITATIONS OF KNOWLEDGE. 315 with concrete observation ; and this because every con- crete observation is limited, whereas the grasp of a few general facts enables us to anticipate an endless multi- tude of observations, and that in cases where Observa- tion would be difficult, sometimes impossible. Science is fertile not because it is a tank but because it is a spring. The grandest discoveries, and the grandest applications to practice, have not only outstripped the slow march of Observation, but have revealed by the telescope of Imagination what the microscope of Obser- vation could never have seen, although it may after- wards be employed to verify the vision. No reader of these pages will misunderstand the reach of this remark, or suppose that it warrants any neglect of Observation through a too confident reliance on Imagination and Reason ; for Imagination and Rea- son are only powerful as the organised results of pre- vious Observation. If Types are to be valid they must be formed by abstraction from concrete experiences, thus enabling Prevision to be only an extension of Vision, and enabling Deduction to rest securely on a basis of Induction. It is the neglect of this single, but indispensable condition, that constitutes the danger of Hypothesis. 86. Certain facts are observed to coexist, or to suc- ceed each other, but the process of their connection is hidden, and we seek to drag into light the facts which come between the facts which are seen. There is a gap to be filled up. How ? Not by direct vision. Then by indirect vision. We guess, and our guess has a Greek name, Hypothesis, namely, that which is placed under, and supports the observed facts ; it is the imagi- native arch thrown over the gap which we may traverse 316 PROBLEMS OF LIFE AND MIND. as a bridge. Unless this arch rests on solid supports, it will not bear our weight ; and many a visionary hypo- thesis turns out to be no better than the arch of the rain- bow, beautiful to look upon, impossible to walk upon. It is therefore of the utmost importance to ascertain the conditions of solid support. Guessing has a wide and capricious range ; it is oftener wrong than right ; but worse than all is the fatal facility with which the mind accepts a guess in lieu of vision, believing in the image it has formed out of materials from within, as if it were an image formed of materials from without ; and thus, while the probabilities of error are enormous, the pertinacity with which error once formed on very slight evidence is held, resists all but demonstrative evidence against it. Hypothesis thus becomes pernicious. It retards Science by arresting inquiry; it quiets the unrest of the mind with the anodyne of a phrase, and seems to explain what it only rebaptises. It also re- tards Science by misdirecting inquiry, stimulating the mind to seek direct relations where none exist. 87. These dangers have been eloquently exposed by many writers, and need not here be illustrated. Yet while it would be difficult to express too strong a condemnation of the lax unscientific use of Imagi- nation, which has brought Hypothesis into disrepute, it would be difficult to exaggerate the immense, the indispensable service of Hypothesis in the con- struction and advancement of Science. How largely Newton availed himself of its aid, and how he repro- bated it, have already been indicated (Introd., 49). When Newton said that Hypothesis had no place in ex- perimental philosophy, he probably meant that we must not take fancies for facts, guesses for conclusions ; which THE LIMITATIONS OF KNOWLEDGE. 317 is a warning not the less needed because it seems so obvious. But if we regard Hypothesis in its true light* namely, that of ideal experiment, the tentative process of trying which among many possible conceptions best accords with perceptions, that experimental character will place it beside the tentative process of trying which among many physical conditions will determine a mo- dification of the result. Cuvier, in his dispute with Geoffroy St Hilaire, was always insisting on the dangers of Hypothesis; and elsewhere proclaimed it his guiding principle to adhere simply to the " exposition of positive facts ;" a declara- tion which occasionally meets with the fatal objection that what he expounds as facts have been proved to be fictions ; and which may always be met by the unde- niable statement of Laplace, that if men had limited their efforts to the collection of facts, Science would have been only a sterile nomenclature, and would never have revealed the great laws of Nature. Without Hypothesis no step could be taken. Our very percep- tions involve it. Nay more, I venture to affirm that the wildest flights of Imagination consciously sweeping round the circle of Experience, and alighting where it pleases, are legitimate tentatives of scientific Research, if only they submit to the one indispensable condition (unhappily too often neglected) of ultimate verification. The profound remark of Copernicus,* that the value of * From GASSENDI'S work Nicolai Copemici Vita, 1655, p. 319, 1 find that the remark to which reference is made in the text was perhaps only due to COPERNICUS in the sense that he countenanced its publication, for it was not written by him, but by his disciple OSIANDER in the preface which he added when he gave the work of Copernicus to the public. It may therefore have been simply une precaution oratoire to render the heretical doctrine of the earth's movement less offensive. 318 PROBLEMS OF LIFE AND MIND. an hypothesis consists in reconciling Calculation with Observation, has not been duly appreciated ; so little has it been appreciated that most people would echo Bacon's sneer at Copernicus as " the man who thinks nothing of introducing fictions of any kind into Nature provided his calculations turn out well." The answer to this sneer is the triumphant achievements which are effected by the introduction of avowed fictions among the arti- fices of Research. 88. It is not only in Algebra that in endeavouring to form an equation we often begin by assigning any value we please to the unknown quantity, and submit this to all the operations necessary for ascertaining whether it answers the conditions or not, so that the result is to the correct one as the assumed value is to the unknown one.* We may employ what materials we please for our scaffolding, on the sole proviso that since this scaffolding is not the house, it must be care- fully taken away again,when the house is constructed; we must not allow the beams, ropes, and ladders, used as auxiliaries, to thrust themselves discordantly into the structure itself. No doubt great skill is needed in the selection of auxiliaries, and in avoiding the danger of thrusting parts of the scaffolding into the structure ; and the formation of true hypotheses is the severest task for the scientific imagination ; while the invention of false, or illusory, hypotheses is the sterile abundance of an untrained imagination. The principle here proclaimed is the absolute freedom of introducing any elements in * "Personne ne reVoque en doute 1'exactitude des rdsultats qu'on obtient par le calcul des imaginaires, quoiqu'elles ne soient que des formes alge"briques et des hieroglyphes des quantite"s absurdes." CARNOT : La M&aphysique du Calcul Infinitesimal, p. 120. Compare also FECHNER : Psychophysik, ii. 40. THE LIMITATIONS OP KNOWLEDGE. 319 the formation of an equation, on the understanding that nothing which is introduced as an auxiliary be per- mitted to appear in the result. On this principle we may admit the conception of Atoms, even if we regard them as pure fictions ; and we may endow these Atoms with any shape, size, or qualities we please, if thereby calculation can be aided; provided always that we assume nothing absolutely contradictory of experience, but only what is in harmony with experience : that is to say, the Atoms must be Extra-sensible, not Supra- sensible. The truth, or falsity, of the existence of these Atoms is another question altogether ; and need never be raised so long as we treat them purely as auxiliaries, not realities. Thus, suppose I assume the Atoms to have the shape of an ellipsoid, and to be capable of moving only in rotation about three fixed axes, but in- capable of vibration or translation. The assumption is inadmissible, because it is contradictory of experience, which rejects the idea of rotation as an exclusive form of motion. If, however, I merely assume that under given conditions the only motion possible is that of rotation, and I deduce from this some exact results, not otherwise obtainable, my assumption is valid, since it is proved thereby to represent some relation of the real agents. But that this relation is only one among many is proved by the simple fact that bodies expand, which would be impossible unless there were internal motions, not necessarily of vibration. 89. Again, the hypothesis of an undulating Ether, so largely employed in modern inquiries, is perfectly legitimate, and is proved to be so by its results. The vast array of phenomena which it explains, and the striking anticipations of Observation which it has 320 PROBLEMS OF LIFE AND MIND. effected, do not indeed prove the reality of the Ether, though they render its existence highly probable. The hypothesis with its dependent calculations brings into view a larger number of conditions which must be ac- cepted as true, even when the ether itself is rejected. The controversy on this question is too often confused by the want of a clear recognition of the principle I am here expounding, namely, that the value of the hypo- thesis is one thing, its evidence for the reality of an Ether is another. We are not bound to prove the ex- istence of the Agent, so long as we confine ourselves to the hypothesis of an Agency acting on hydrodynamic or molecular dynamic laws ; and so long as we do not allow more than the demonstrated Agency to enter into the final equation ; such as would be the case if from any assumed, but not demonstrated, properties of the Ether we deduced conclusions at variance with, or not verifiable by, experience. And the reason of this reliance on the Agency, irrespective of the reality of the Agent, is that at any rate what is thus demonstrable must be true of the relations of the Agent, be that Agent what it may. Let this Ether be only an atten- uated form of ponderable Matter, or a fluid, or a solid, sui generis, we know at least that its mode of action in certain phenomena is explicable on dynamic laws. But there are phenomena which these laws have hitherto failed to explain. Hence we conclude that the Agent has other modes of action besides those already revealed, that the dynamic laws require to be supplemented by some other laws of molecular movement. 90. Some years ago I suggested a course of inquiry which was unhappily beyond my own power, but which in the hands of a powerful analyst might resolve some THE LIMITATIONS OP KNOWLEDGE. 321 of the difficulties at present attending the undulatory theory. That theory only regards the movements of vibration, leaving out of sight the movement of rota- tion. But if the Ether be assumed as atomic, these atoms must have form ; their geometric properties en- tail corresponding dynamic properties ; and they cannot have movements of translation without also having ro- tation. Now if the mathematical investigation of the movements of translation were supplemented by an in- vestigation of the movements of rotation, it is eminently probable that this new analysis would disclose the equa- tions necessary for the reduction of those phenomena which still resist mathematical analysis.* 91. Be this as it may, the achieved results are ample justification of the hypothesis of an Ether. I cannot, therefore, agree with Comte in his polemic against the hypothesis, a polemic which could only avail against those who proclaimed the reality of the Ether. But he will not allow it to have even an auxiliarv value. "A */ la verite" les physiciens se defendent vivement aujour- d'hui d'attacher aucune realite intrinseque a ces hypo- theses, qu'ils preconisent seulement comme des moyens indispensables pour faciliter la conception et la combi- naison des phenomenes. Mais n'est ce point la Tillusion d'une positivite incomplete, qui sent la profonde inanite' de tels systemes et pourtant n'ose point encore s'en passer Vt To this question I answer, No ; and in so answering it, believe I am standing strictly within the * Prof. TAIT informs me that some distinguished investigators, notably Professors THOMSON, RANKINE, and CLERK MAXWELL, have been work- ing at this subject for years. My absence from England during the printing of these sheets prevents my giving more precise information on this point. f Philos. Positive, ii. 441. VOL. I. X 322 PROBLEMS OF LIFE AND MD?D. sphere of positive science. But as Comte's view is shared by some eminent writers, we are bound to con- sider it carefully and impartially. Hypotheses relate either to the Agents, or the Agen- cies, which link together the observed phenomena, t. e. y the qualitative or quantitative elements which are the determinants of the phenomena. Sometimes we know the determinant (Agent, or Substance), but are ignorant of its mode of operation in effecting the change observed. Sometimes we know this mode of operation, or Agency, but are ignorant of the Agent. Thus we know that oxygen is the agent in the transformation of venous into arterial blood^ and in the decomposition of the tissues necessary to the liberation of organic force ; but the mode in which this is effected, whether by direct or indirect oxidation, is still a mystery. On the other hand, we know that the agency of Light is that of wave-movement; but the moving agent is unknown. The mode of operation of what is called chemical Af- finity is known, but Affinity itself is unknown. "We know as an experimental fact that Heat is Motion, and therefore the laws of Motion are laws of Heat ; but we are still unable to explain many of the phenomena, " because we do not know what is moving nor how it moves. Results of the theory in which these are not involved are experimentally verified."^ 92. Now, any hypothesis introduced either respect- ing the Agent or the Agency, is justified if it facilitates Research and conforms to the test of Verification ; and it can only be called upon to show evidence for its reality, when we declare it to be the real Agent, and when as such it enters into the final equation. Whether * THOMSON and TAIT, Natural Philosophy, L 311. THE LIMITATIONS OF KNOWLEDGE. 323 the Agent which determines the orbit of a planet be an Angel seated in the sun, or an Attraction issuing forth from the sun and the planet, is a matter of indifference, so long as we admit nothing but the law of the Agency into our final equation, and allow neither any assumed properties of Angels, nor any assumed properties of an occult Attraction to find expression. Again, whatever hypothesis we form respecting the Agent of Heat will be indifferent, so long as we confine our equation to the Agency. Thus, while assuming Heat to be Motion, we only select from all the possible forms of Motion those of Vibration and Rotation, which constitute the known Agency ; and since the results of calculation thus obtained agree rigorously with observation, we conclude that we have detected something at least of the real mode of operation, let the Agent be a peculiar substance moving amid the particles of the heated body, or simply the molecules of the body itself in a state of agitation. Comte is right in saying that it would be difficult to see how the dilatation of a body by heat is explained by the idea of an imaginary fluid interposed between its molecules, tending constantly to augment their intervals, since we should then have to inquire whence the fluid gained its elasticity, which is assuredly less intelligible than the primitive fact. But although the introduction of a fluid as an Agent explains no- thing, the fluid as an Agency i.e., its hydrodynamic laws explains much. Of course, any other hypothesis that, for instance, of expansion being due to the in- creased oscillation of the molecules may take the place of this hydrodynamic hypothesis ; and it will remain for the advocates of each to justify the preference by the greater sum of verified results. The two hypotheses 324 PBOBLEM3 OF LIFE AST) MtN'D. of Light both explained many of the phenomena ; and the one was finally victorious only when it succeeded in explaining what its rival stumbled over as a contra- diction. The undulatory hypothesis itself^ as usually stated, may perhaps have to yield the place to another. 93. Let us never forget that the agreement of observa- tion with calculation does not prove the reality of the Ether as an Agent; it only proves that the mode of opera- tion of the real Agent (whatever that may be) is to some extent such as we assume ; and it is only because we are in doubt of the reality that we call upon Hypo- thesis to aid us. Were the reality proved, there would be no longer an hypothesis, the supposition would give place to a demonstration. To demand that what are avowedly fictions should be called to prove their reality, is inconsistent Hypotheses are guesses, aids to re- search, and not to be treated like the results. There are good and bad guesses ; and unhappily their inven- tors are generally careless in verifying them. Some- times verification is, in the nature of the case, not attainable ; we then rely on probability. Our guesses may be ranged under three classes : 1, the Real Hypo- theses, which being intrinsic are explicative ; 2, the Auxiliary Hypotheses, which being extrinsic, are merely aids in construction ; 3", the Illusory Hypotheses. 94. A Real Hypothesis is one which explains ob- served phenomena, and anticipates the results of future observation, by means of some Agent or Agency knoirn to be present among the elements of the observed phenomenon, the precise relations of which, however, as determinants, are not known. Thus the phenomenon of Expansion in gases and solids is explained as the wider sweep of the oscillating molecules. That the THE LIMITATIONS OF KNOWLEDGE. 325 molecules are in a state of oscillation is known; the laws of oscillation are sufficient to account for the phenomenon, without the intervention of any extrinsic agency. If a vibrating fluid be introduced to account for the oscillation of the particles, and be absolutely restricted to the simple office of transmitting vibrations, without any admixture of undemonstrable properties, the hypothesis still keeps within the sphere of the known ; and all the demand we can make on it is that it shall explain what we observe. 95. When the x is obtained in an equation, what is known of it (its functions) must satisfy the equation, otherwise no step in advance is made. Thus, if we introduce a Spirit as the Agent in certain changes, how does this enlighten us, unless we know the properties of the Spirit and its laws of action ? Whereas if in- stead of a Spirit we introduce Attraction, although we may be equally ignorant of this Agent, if we know the laws of its action, through these known laws the equa- tion is satisfied. Newton's great hypothesis is a fine example. It was what I have called a Real Hypothesis, what he would have put forward as legitimate be- cause it was "deduced from the phenomena." He began by assuming that the force which at each instant deflects a planet from its tangent (the observed fact of deflection leading to the assumption of a deflecting force), and which causes the planet to move in a curve round the sun (another observation), is a force tending directly towards the sun. He then showed that, on such premisses being granted, the conclusion follows that the planet will describe equal areas in equal times and this conclusion Kepler's first law had already established (subject to the qualification I have before 326 PROBLEMS OF LIFE AND MIND. noted, and accepting the law in its ideal aspect). Newton further showed that if the deflecting force did not tend towards the sun, the planet would not describe equal areas in equal times. Having thus demonstrated that the hypothesis necessarily carried the conclusion which observation disclosed, and that a contradictory hypothesis would not carry such a conclusion, his assumption was established as a truth, his guess was ' deduced from the phenomena.' 96. It is characteristic of all Eeal Hypotheses that they pass by Verification into inductive truths. Since they admit nothing extrinsic to the phenomena, directly the right guess has been intuited the process of de- monstration requires no elimination of auxiliary ele- ments. Hence it is obvious that our first aim should be to frame hypotheses of this kind, and to seek for an explanation of phenomena in Agents or Agencies al- ready known, or surmised to be present (RULE XV.), But it is no less obvious that were we to confine In- quiry to such a procedure, the advance of Science would be extremely slow, since it is seldom that we have this solid foundation to stand on, and it mostly happens that we do not know, but are forced to guess, what is the Agent or Agency in operation. Hence the employ- ment of Auxiliary Hypotheses. An Auxiliary Hypothesis is a conscious fiction by which Imagination pictures what would be the effect of a given Agent, or Agency, if present. It is purely a tentative process, like that of assigning an arbitrary value to an unknown quantity. The advantage of such a tentative process will of course depend on the degree in which the imagined agency resembles the actual agency; and for this purpose it must be of THE LIMITATIONS OF KNOWLEDGE. 327 a character strictly analogical with those of the ele- ments known to be present in similar phenomena (RULE XV.) For example, the complications of the planetary movements would baffle all rational theory were it not for the various fictions by which astronomers turn the difficulty ; and especially by that of the Type presented in the problem of two bodies, one of which is assumed to be fixed. It is to this Type, avowedly a fiction, that the real movements are reduced by successive approximations:; and its comple- tion is Lagrange's celebrated theory of the variation of arbitrary constants, which treats the effective move- ment of any planet as if it were really elliptical but with variable elements instead of constant elements. " So many of the properties of matter," says Professor Clerk Maxwell, " can be deduced from the hypothesis that their minute parts are in rapid motion, the velocity increasing with the temperature, that the precise nature of this motion becomes a subject of rational curiosity. Daniel Bernouilli, Herapath, Joule, Kronig, Clausius, &c., have shown that the relations between pressure, temperature, and density in a perfect gas can be explained by supposing the particles to move with uniform velocity in straight lines, striking against the sides of the containing vessel and thus producing pres- sure. It is not necessary to suppose each particle to travel to any great distance in the same straight line ; for the effect in producing pressure will be the same if the particles strike against each other; so that the straight line described may be very short. Clausius has determined the mean length of path in terms of the average distance of the particles, and the distance between the centres of two particles when collision 328 PROBLEMS OF LIFE AND MIND. takes place. We have at present no means of ascertaining either of these distances; but certain phenomena such as the internal friction of gases, the conduction of heat through a gas, and the diffusion of one gas through another, seem to indicate the possi- bility of determining accurately the mean length of path which a particle describes between two successive collisions. In order to lay the foundation of such investigations on strict mechanical principles, I shall demonstrate the laws of motion of an indefinite number of small, hard, and perfectly elastic spheres acting on one another only during impact. If the properties of such a system of bodies are found to correspond to those of gases, an important physical analogy will be established which may lead to more accurate knowledge of the properties of matter. If experiments on gases are inconsistent with the hypo- thesis of these propositions, then our theory, though consistent in itself, is proved to be incapable of explaining the phenomena of gases. In either case it is necessary to follow out the consequences of the hypothesis. " Instead of saying that the particles are hard, elas- tic, and spherical, we may, if we please, say that the particles are centres of force of which the action is insensible except at a certain small distance, when it suddenly appears as a repulsive force of very great intensity. It is evident that either assumption will lead to the same results."* 97. The freedom which Imagination is here al- lowed in the creation of conscious fictions, does not * MAXWELL: Illustrations of the Dynamical Theory of Gases; Philos. Mag., 1860, p. 19. THE LIMITATIONS OP KNOWLEDGE. 329 prevent these guesses being submitted to the most rigorous tests ; and the value of such fictions appears in the aid they furnish to calculation/ We find Mr Maxwell not only explaining the pressure of a gas by this assumption of elastic particles moving in straight lines the square of the velocity being proportional directly to the absolute temperature and inversely to the specific gravity of the gas at a constant tempera- ture, but also that the number of particles in a unit of volume is the same for all gases at the same pressure and temperature : a result in striking accordance with the chemical law that equal volumes of gases are chemi- cally equivalent. Again, it is a pure fiction which transfers the circular nature of the Earth and all the geometrical properties of the circle to the Heavens. That the Earth is a sphere, or approximates to one, is a fact; but that it is enclosed in a heavenly sphere is a sheer fiction ; yet it is the celestial circles by which the terrestrial latitudes and longitudes are calculated; and were it not for this fiction, which connects Geography with Astronomy, our geographical science could not have been constructed. 98. It is necessary to insist on the strictly scientific use of the Imagination in constructing these auxiliaries, because Newton has in emphatic language condemned them, though his own practice wehave seen to be a splen- did vindication of them. He pronounced hypotheses illegitimate which were not deduced from the pheno- mena ; in fact it was these only that he called hypo- theses. "Whatever is not deduced from the phenomena," he says in the famous Scholium, "is to be called an hypo- thesis; and hypotheses, whether metaphysical or physical, have no place in experimental philosophy." The weight 330 PROBLEMS OF LIFE AND MIND. of his authority has pressed Hypothesis into the mire, where it is trodden on by the feet of writers who are by no means slow to profit by its services ; and thus, in spite of its services, Hypothesis has become the pariah of research. 99. The rival hypotheses respecting Light are mani- festly auxiliary. The corpuscular is now discredited, but it was once, if erroneous, effective. Some writers declare that there was this initial defect in it, that only on the supposition of a corpuscle being visible and tangible, could the hypothesis have been justifiable. This is precisely the objection urged by Comte, Mill, and others against the undulatory hypothesis. If the Ether be admissible, although no one has seen or could see it, then surely luminous corpuscles are admissible ? Neither of these Agents is known to be present in luminous phenomena ; neither is positively known to exist. But the valid ground for the rejection of the one hypothesis, is not that the Agent is proved to be absent, but that the Agency invoked as an auxiliary fails to explain the phenomena ; whereas the Agency invoked in the other case, although still incompetent to explain all the phenomena, explains so many, that its aid is more effective, and therefore preferred. The vortices of Descartes have long since passed into the rag-shop of worn-out finery ; and those who see the hypothesis huddled among many others equally dis- carded, forget that it was once a part of the furniture of Science. In estimating an opinion we must always take the historical standpoint ; for the suggestion which from a later standpoint appears inept, may be recog- nised as ingenious from the earlier. The vortices of Des- cartes thus viewed present an example of the three THE LIMITATIONS OF KNOWLEDGE. 331 stages through which most hypotheses must pass, its stage of indispensable though temporary aid, its stage of application and verification, and its stage of final dis- placement in favour of some more successful rival. Placing ourselves for a moment at the point of view prevalent when Descartes devised the vortices, we at once see the enormous and indispensable aid it furnished, simply by the introduction of the idea of mechanical law where even the great Kepler could only conceive the action of genii. A philosophy which explained pheno- mena by the aid of such genii could only be set aside by a philosophy which explained the phenomena on mecha- nical grounds. And although when Celestial Mechanics had received a sure foundation by the discovery of gravi- tation, the hypothesis of Vortices was an obstruction, not an aid, its doom was not sealed until geometers and astronomers proved that it was in contradiction with known facts and known mechanical laws ;* and proved that another hypothesis accomplished all it pretended, and explained what it left inexplicable. Here, as else- where, those who declared that it was impossible to theorise without such an aid, were answered by a more effectual theorising with another. 100. Among auxiliaries a distinction is to be made between those which relate to Agencies and those which relate to Agents. In the first class are the quantitative hypotheses of mathematical physics, where, in entire ignorance of the Agents, we can, from mathematical laws, at least deduce their mode of operation. The * " Kien ne serait plus satisfaisant pour 1'esprit que la physique celeste de M. Descartes si elle cut pu soutenir 1'epreuve de 1'examen et de 1'obser- vation." MONTDCLA : Hist, des Math&natiqves, ii. 537. Compare NEWTON : Principia, Book IL, Sec. XI., SchoL, to prop. 411 ; and the general Scholium to Book III. 332 PROBLEMS OP LIFE AND MIND. nature of Heat, Electricity, or Magnetism, may be un- known, but some of their quantitative laws are ab- solutely known. Yet auxiliary hypotheses have always to be treated as auxiliary, and, when applied to physical facts, require numerous modifying and limiting con- siderations, such as are always requisite in passing from the abstract to the concrete. Thus Newton says : " I use the words attraction and impulse not defining the species or physical qualities of forces but investigating the quantities and mathematical proportions of them. In mathematics we are to investigate the quantities of forces with their proportions consequent upon any con- ditions supposed ; then when we enter upon physics we compare . those proportions with the phenomena of Nature, that we may know what conditions of those forces answer to the several kinds of attractive bodies. And this preparation being made we may agree more safely concerning the physical species, causes, and pro- portions of the forces.* " The history of physical science," says Prof. Challis, " seems to show that theoretical investigation proceeds in but one course, that of deducing quantitative laws, by means of solutions of equation, from known or hypothetical principles." 101. The second class of hypotheses is of smaller value. Unless we already know the law of the Agency, our guess at the Agent is almost certain to be errone- ous; a consideration which should make us particularly cautious. Even when we know the law, there is great danger of missing the one out of many possible Agents which may be involved. For example, the Electro- dynamic theory of Ampere merely expresses the law of * Principia, Book I., Section XL, Scholium. THE LIMITATIONS OF KNOWLEDGE. 333 the Agency : the experimental data of the action of closed currents on each other give expressions for the mathematical law of the action which one element must exert on another. But Weber seeks the Agent, and his hypothesis is that of an electric current formed by the motion of particles of two kinds of electricity moving in opposite directions ; an hypothesis which is open to many objections.* 102. Another example is the hypothesis propounded by Young, and adopted by Helmholtz, of three special retinal fibres for the three primary colours ; or the kin- dred hypothesis of Helmholtz, that the auditory nerve has special fibres for notes of particular pitch. I shall examine this more in detail in a subsequent Problem. Enough for the present to remark that these different fibres are assumed Agents, and there must first be de- monstrated the presence of fibres having different struc- ture and properties ; no attempt has been made to de- monstrate this, and we cannot accept them merely on the ground of the Agency, i.e., merely because the known law of distinct primary colours suggests the presence of distinct fibres. The more so because the Agency may be otherwise interpreted. I shall hope to make clear that the Agency can be rigorously deduced from the general Law of Grouping which determines all sensitive phenomena, each colour and each tone being simply a special group of neural units. We do not need three different fibres, since one fibre can readily be conceived vibrating with different nodes, like a rod or cord ; and the principle of the superposition of small oscillations may be applied to nerves as to rods. 103. Whether an hypothesis refers to the Agent or * See THOMSON and TAIT : Natural Philosophy. 334 PROBLEMS OF LIFE AND MIND. the Agency, the one thing needful to be steadily borne in mind is the one thing commonly neglected, namely, that while any supposition which can furnish aid is justified by the assistance we derive from it, no suppo- sition can be accepted for more than instrumental aid, no supposition can be allowed to take the place of a truth, until it has itself been submitted to the opera- tions which establish a truth. An hypothesis may be false, yet help us to a truth ; but no demonstration of the truth of any process proves that the hypothesis which explains the process is true. The existence of Ether is not demonstrated because the hypothesis of an Ether is the most satisfactory means we have at pre- sent of explaining luminous phenomena; all that is proved is that the hypothesis is effective. This caution is the more needful because of our tendency to consider the verification of a result as a proof of the independent truth of the hypothesis. Because the supposed Agency is adequate, is it therefore to be held as existent ? La- place mentions an example of the danger which besets auxiliary hypotheses, " quand on les realise au lieu de les regarder comme des moyens de soumettre les obser- vations au calcuL" Dominic Cassini, he says, in form- ing a table of refraction, started from the simple sup- position of a constant density in the atmosphere. This table was exact at the heights at which the stars are usually observed, and was adopted by astronomers ; and the hypothesis that the refraction augments with the elevation gained universal acceptance until Bouger proved, by observations made at Quito, that the refrac- tion at that height instead of being increased was diminished.* * LAPLACE : Exposition du Systeme dv Monde, i 191. THE LIMITATIONS OF KNOWLEDGE. 335 104. Were Newton's dictum to be followed, no auxil- iary hypothesis would be permitted. If, however,, we clearly understand its nature, and do not confound an instrument of construction with an element of construc- tion, we may allow Imagination unrestricted licence. Any operation is legitimate by which we can submit observations to calculation, or by which new observa- tions are rendered practicable. Suppose I am studying the evolution of an ovum, and unable by the micro- scope to see the mutual relations of its parts, which could be seen were a thin section made of it; the delicacy of the structure prevents my making such a section ; I must therefore seek some external aid. A solution of chromic acid hardens the ovum sufficiently to enable a section to be made. Nothing can be more foreign to the organic tissue than this chromic acid ; yet by its aid I am enabled to detect certain constituent elements in that tissue ; and no one would object to my employing it, on the ground that it was extra- organic. But if, after employing chromic acid as an auxiliary, I allowed it to enter into the construction, i.e., if in treating of the chemical and physical com- position of the tissue, I introduced among the con- stituents those results which were due to the agency of the acid, then, indeed, every one would rightly ob- ject to the procedure. And it is this error which is committed when hypotheses originally introduced as aids in bringing phenomena into appreciable relation, are finally allowed to appear in the result.* * " L'objet de tout calcul se reduit a trouver les relations qui existent entre certaines quantites proposdes, mais la difficult^ de trouver im- mediatement ces relations oblige souvent de recourir a Tentremise de quelques autres quantitds qui ne font point partie du systeme propose, mais qui par leur liaison avec les premieres peuvent servir comme inter- 336 PROBLEMS OP LIFE AND MIND. 105. The Illusory Hypothesis must be broadly dis- tinguished from the other two classes. It is not deduced from the phenomena; it is not an aid; it is simply a restatement of the observed facts in a compendious, and generally ambiguous, phrase. It rebaptises an observation. Yet such is the influence of mere naming, that the rebaptism of our ignorance seems to be an illumination, and exercises a charm that is all the more obstructive to Kesearch, because we often find a positive advantage in a phrase which condenses a multitude of details ; and the advantage of the formula leads us to confound it with a principle. To many minds the word Affinity is more than a term ; and when chemists say that oxygen unites with hydro- gen because these gases have a strong Affinity, many persons accept this as an explanation. In former days a multitude of phenomena were condensed in the formula of the fuga vacui. Nature was said to ' abhor a vacuum/ This phrase named, and by naming linked together, observed facts of suction, breathing, the rise of water in a tube, &c. ; and had it been limited to the simple expression of the observed facts, it would, like the term Affinity, have been of unimpeachable advantage. The error lay in taking the formula for a principle, and supposing that it explained what it simply named. Believed to be a principle, its action was necessarily generalised beyond the sphere of obser- vation ; and thus Mersenne imagined a siphon which should go over a mountain ; whereas the real law of mddiaires entre elles. On commence done par exprimer les relations qu'elles ont toutes ensemble ; apres quoi on elimine du calcul celles qui n'y sont entrees que comme auxiliaires afin d'obtenir entre les quantites proposers seules les relations immediates qu'on voulait d^couvrir." CAENOT : La Mtiaphysique du Calcul Infinitesimal, p. 21. THE LIMITATIONS OP KNOWLEDGE. 337 suction, on which the siphon depends, is limited to drawing water to the height of 34 feet above that, the ' horror of a vacuum ' ceases. 106. In our own day writers who ridicule the fuga vacui are quite ready to invent or accept Illusory Hypotheses of the same calibre. They confidently assign phenomena to Electricity, Ozone, Polarity, Nerve - atmospheres, Eepulsive atmospheres, Psychic force, Vital force, and the like. Nay, it is popularly supposed that the invention of such hypotheses is an ex- ercise of the Imagination ; and on this ground soberer thinkers are wont to decry Imagination, believing it to be the pest of Science. Such hypotheses are indeed a pest ; but so far from their source being Imagination, it is precisely a defect of Imagination which forms their nidus. To imagine a natural process is to see the Agents or Agencies which are really operative, or which, if pre- sent, would act so as to produce the result observed. But this mental picture of the unseen process is given only to the highest minds equipped with exact knowledge. In Science, as in Art, any feeble mind can satisfy itself by vaguely supposing that something may in some way or other (not specified) determine the changes which take place ; the difficulty is in precise vision. But precision is the one quality which impatient minds least appreciate ; and therefore Illusory Hypotheses spring up like mushrooms in half-. long before he arrives at mathematical truths ; knows, and can state his reasons for knowing, that air is neces- sary to respiration, and food to growth, long before he has any suspicion that two things equal to a third must be equal to each other, or that parallel lines if prolonged would not meet ? 190. The objects of mathematical study are reals, in the same degree as that in which the objects of any other science are reals. Although they are abstractions, we must not suppose them to be imaginary, if by imagin- ary be meant unreal, not objective. They are intelligi- bles of sensibles: abstractions which have their concretes in real objects. The line and surface exist, and have real properties, just as the planet, the crystal, the plant, and the animal exist, and have real properties. It is often said, that " the point without length or breadth, the line without breadth, and the surface without thick- ness are imaginary : they are fictions ; no such things exist in reality." This is true, but misleading. These things are fictions, but they have a real existence, though not in their insulation of ideal form, for "no idea exists out of the mind. These abstractions are the limits of concretes. Every time we look on a pool of water we see a surface without thickness ; every time we look on a party-coloured surface we see a line without breadth as the limit of each colour. Both surface and line as mathematically defined are unimaginable, for we can- not form images of them, cannot picture them detached ; but that which is unpicturable may be conceivable; and the abstraction which is impossible to Perception and Imagination, is easy to Conception. It is thus that sen- sibles are raised into intelligibles, and, in the construc- tions of science, conceptions take the place of percep- THE LIMITATIONS OF KNOWLEDGE. 421 tions. But the hold on Eeality is not loosened by this process. When we consider solely the direction of a line, we are dealing with a fact of Nature, just as we are dealing with a fact of Nature when we perform the abstraction of considering the movement of a body, irre- spective of any other relations. "We no more think that the line is unreal, than that motion is unreal ; we no more believe that a surface can exist without an under surface, than we think that a movement can take place without a moving body. M. Delbceuf per- tinently remarks that if Mathematics be called ima- ginary, there would be equal justice in our saying to Newton and Laplace : " Your celestial mechanics is false, for there are not in Nature bodies which are only heavy."-"' 191. Not only is it misleading to call the objects of Mathematics imaginary, it is also incorrect to call them generalisations. They are abstractions and intuitions. Any particular line that we can draw, or imagine, has breadth; any particular circle is imperfect; conse- quently generalised lines and circles must have breadth and imperfection. "Whereas the line, or circle, which we intuite mathematically is an abstraction, from which breadth or imperfection has been dropped, and the figures we intuite are these figures under the form of the limit. 192. Unless the objects of Mathematics were real, in the sense just explained, it would be absurd to sup- pose that the relations intuited could be applied to the discovery of other real relations. A moment's inspec- tion shows that the properties of angles and circles are discovered and demonstrated by the same principles * DELBCEUF : ProUgom&nes de la G&m&rie, p. 16. 422 PROBLEMS OF LIFE AND MIND. that are applied to the discovery of gases or organic processes. Gauss, whose authority on such a subject weighs against a whole academy, declared Geometry to be the " science of the eye ; " and Prof. Sylvester, also a very considerable authority, declares that most if not all the great ideas of modern Mathematics had their origin in Observation. Among the surprising examples cited by him may be named Sturm's theorems on the roots of equations " which stared him in the face in the midst of some mechanical investigations connected with the motion of compound pendulums" and the discovery of the method of continued fractions by Huyghens, " to which he was led by the construction of his planetary automaton." * Hence it is that most of the difficulties in this science are difficulties rather of Intuition than of Reasoning ; and most of the ' vexed questions ' which have occupied geometers notably that respecting parallels and that respecting a fourth dimension in space have arisen from neglect of Intuition. Because analysts are accus- tomed to operate on symbols they at last begin to assign a sort of talismanic virtue to symbols which will evoke results in defiance of intuitions. But here the words of the illustrious Poinsot deserve attention : "Ce n'est done pas dans le calcul que reside cet art qui nous fait de*couvrir ; mais dans cette considera- tion attentive des choses ou 1'esprit cherche avant tout a s'en faire une ide"e, en essayant, par 1'analyse pro- prement dite, de les decomposer en d'autres plus simples, afin de les revoir ensuite comme si elles * Address to the Mathematical Section of the Brit. Association, 1869. Reprinted in Nature, i 238. THE LIMITATIONS OF KNOWLEDGE. 423 ^talent forme'es par la reunion de ces choses simples dont il a une pleine connaissance." * 193. Even in the higher developments of the Cal- culus, where sensible experiences seem most widely departed from, it is easy to trace a sensible origin for the extra-sensible intuitions ; precisely as in Dynamics and Physics we detect the sensible origin of intuitions which transcend Sense, e.g., uniform rectilinear Motion and Atoms. If there is one conception which might be supposed to justify a metempirical origin, it is that of infinitesimals. Now we have this conception, it seems that it might have been evolved d priori, and that the active intellect of the Greeks might have reached it through their Method of Exhaustions. What is the fact, however ? It is that the ingenious Greeks were arrested in their course by the impossibility of reaching a conclusion now seen to lie so near at hand. Nor was it until Mathematicians had mastered the theory of the composition of motions, by which the path of a projectile was seen to be compounded of two straight lines in different and unceasingly changing directions, that the conception of infinitesimals arose. 194. Enough has been said, some will think more than enough, to establish the first part of our thesis, that Mathematics is a science of Observation, dealing with reals, precisely as all other sciences deal with reals. It would be easy to show that its Method is the same : that, like other sciences, having observed or discovered properties, which it classifies, generalises, co-ordinates and subordinates, it proceeds to extend discoveries by means of Hypothesis, Induction, Experi- * POINSOT : TMorie nouvette de la rotation des corps, p. 78. 424 PROBLEMS OF LIFE AND MIND. merit, and Deduction. On the large use of Hypothesis and Deduction, there need be nothing said here, since no one disputes their importance. Induction and Ex- periment, however, demand consideration. 195. By some minds the very suggestion of mathe- matical truths being reached by Induction is resisted ; yet it is certain that not only does Induction play a part, but according to some writers that part is very considerable. " Induction and analogy," says Professor Sylvester, " are the special characteristics of modern Mathematics in which theorems give place to theories, and no truth is regarded otherwise than as a link in the infinite chain." Some of the divergence on this point must be attributed to the divergent conceptions of what constitutes Induction, much that is even by Mr Mill included under that head being either Intuition or Description. No one can refuse to recognise it as purely inductive when having calculated a number of terms of a series, and ascertained the law of the series, we fill up the succeeding terms without calculating them; the induction here consisting in our inference that the succeeding terms will conform to the law of the calculated terms ; an inference which may be false in special cases. It was assuredly an induction by which Fermat concluded that 2 n + 1 is always a prime number when n has the form 2 m , i.e., is 2, 4, 8, 16 . . . ; but Euler showed that the induction was erroneous when n was 32 : for 2 32 + 1 is not prime. 196. If these are pure inductions, the same cannot be said of numerous other examples, also classed under this head. Thus it is no induction by which we conclude that two straight lines having once met do not meet again, but continue divergent : we do not infer this THE LIMITATIONS OF KNOWLEDGE. 425 truth from comparison of instances, we intuite it. Axioms are not inductions, nor can they have been inductively reached ; they are intuitions universalised. I should therefore propose to qualify Mr Mill's state- ment " that every induction which suffices to prove one fact proves an indefinite multitude of facts ; " the am- biguity which lies in the word 'multitude' renders this proposition misleading. An induction cannot prove an indefinite multitude of facts, unless the facts be all repetitions of the one first proved ; if the multi- tude include any facts having other relations than those proved, the inference is erroneous. On this ground it is misleading to call axioms inductions. Let us take a case selected by Mr Mill.* He says that when we have to determine whether the angles at the base of an isosceles triangle are equal or unequal, our first con- sideration is : what are the inductions from which we can infer equality, or inequality'? He specifies eight axioms. Eecourse to inductions is necessitated because " the angles cannot be perceived intuitively to have any of the marks " specified in the axioms, although on examination it appears that they have such marks. I agree with him in considering this a case of discursive, and not of intuitive judgment (153), and that the relations of equality are not immediately presented, but have to be sought and compared. But I cannot consider that the axioms, " things which being applied to each other coincide are equals," or " the whole and the sum of its parts are equals," have the characters of Induction; they are identical equations propositions * See also on this question a paper by Professor ROBERTSON SMITH in the Proceedings of the Royal Society of Edinburgh, translated in the Rev ue des Cours Sdentifiques ; vii, 190. 426 PROBLEMS OF LIFE AND MIND. which exclude all contingency by excluding all infer- ence. No one has more clearly shown than Mr Mill the distinction between inductions properly so called, and "generalisation in which there is no induction because there is no inference : the conclusion is merely a summing up of what was asserted in the various pro- positions from which it was drawn " (I. 324). On this ground we must refuse the character of Induction to those axioms which are simply intuitions generalised. With reference to the particular case chosen, instead of the roundabout demonstration of Euclid, or that pro- posed by Mr Mill, we might reduce it to two intui- tions : 1, The isosceles triangle has equal legs ; this equality is intuited in the terms defined ; 2, The legs being equal, what is seen of the one is seen of the other, i.e., the angle formed by one leg with the base, will be equal to the angle formed by the other. 197. Were Mathematics founded on induction there would be contingency in all its propositions which extend beyond particular cases ; and each conclusion would require experimental verification, direct or in- direct. But this is true only of portions of the science. The greater part is founded on Intuition, and its con- clusions are universal. We are not, however, to suppose that Experiment has little to do here. " A science is experimental," says Mr Mill, " in proportion as every new case which presents any peculiar features stands in need of a new set of observations and experiments, and a fresh induction." Mathematics is experimental therefore, in this, that for every step in advance, as Professor Eobertson Smith has well said, everything not the result of calculation or deduction, there is needed a new figure and a new intuition. The experimentation THE LIMITATIONS OF KNOWLEDGE. 427 is easier, less complicated, than in Physics or Chemistry, the elements are more manageable, because more sharply defined, and we are under no misgiving in dealing with o o o them lest they should include any unknown elements which could affect the result. We are perfectly sure that in bringing a right line into relation with another, it is only this relation we have to deal with ; whereas in bringing a gas into relation with a solid we do not know all the co-operant factors ; and our experiment reveals only some of the actual results.* But although easier, the procedure is similar. The necessity for a new figure, and a new intuition, is shown at every step. We could not reach the simplest proposition without these. Ask any one, not already instructed, whether it is possible to let fall from a point more than one perpendicular on a straight line ? or whether all parallelograms between the same parallels are equal when their bases are equal 1 These propositions are so far from being self-evident, or capable of being de- duced from the axioms and definitions, that he cannot answer until he has seen the figures and intuited the relations. It is by experiment alone, that he can deter- mine the equality of spaces included in figures so unequal as an oblique and a perpendicular parallelogram on similar bases. The chemist has his elements or what he regards as such, and these he combines and recom- bines, in various ways, to watch the reactions, and detect the constant results. The geometer has his elements (points, lines, planes) which he combines and * KANT remarks that philosophy is occupied with clearing up the obscure and complicated Notions which it finds in the mind, whereas Mathematics starts from clearly defined Notions and sees what will issue from their combination. Uber die Deutlichkeit der Grundscitze : Werke, L68. 428 PROBLEMS OF LIFE AND MIND. recombines, watching the results. He draws a circle, and divides it by a straight line into equal halves. This straight line he again divides by another, and thus forms four right angles which fill the space cir- cumscribed by the circle. He goes on adding figure by figure and detecting new relations. Like the chemist he gets at constant results, which enable him to foresee what will be the effect of new combinations : he can calculate as well as count. But although Deduction will carry him much farther than it will the chemist, because of the greater homogeneity of the elements he deals with, it will not suffice without Experiment, Verification. The man who first dis- covered that 7 + 5 = 12, did so by a synthesis which was experimental, not less than that by which the chemist discovered that two volumes of hydrogen and one volume of oxygen constituted water. 198. If in cases so simple Experiment is needed, it may readily be understood how in more complex cases the mathematician essays the demonstration of a pro- blem through a series of tentatives, till he hits upon the construction which discloses the solution, or finds that no solution is possible under the given conditions. Suppose, for example, he asks himself whether there may not be a quadrilateral figure having equal sides, and having two of its angles equal to three right angles : he can not construct such a figure; the attempt would at once disclose that such a figure was inconsistent with the properties of quadrilaterals. Kant has shown that even identical propositions such as a = a, or the axiom ' the whole is greater than its part/ are admissible only because they can be presented in Intuition ; and we formerly saw that even these THE LIMITATIONS OF KNOWLEDGE. 429 are demonstrable, and demonstrable only on the as- sumption of homogeneity. Whence we conclude that Mathematics must be dependent on and limited by Experience, which furnishes intuitions. 199. There has been much dispute as to whether Mathematics are founded on Axioms or on Definitions. This dispute may be cleared up by a more rigorous interpretation of the terms. In the sense commonly assigned, it is neither to Axioms nor to Definitions that the foundation can be ascribed, but to Intuitions ; and to Axioms and Definitions only in virtue of their express- ing Intuitions. Nor let this be considered idle cavilling. For those who take their stand on the Axioms, hold that the whole science is nothing but the analytical unfold- ing of the few Axioms placed at the opening of each treatise : and this seems to be doubly erroneous ; first, because those Axioms are too few for the purpose each step requiring a new intuition, which, when gene- ralised, becomes a new Axiom ; secondly, because they derive their whole validity from Intuitions. Both ob- jections may be condensed in one : the science is syn- thetical and not analytical. Take the Axioms of Euclid and try by them alone to deduce the Pythagorean theorem, and it will be found as idle as the attempt to deduce the action of a poison from the axiom * every effect has its cause/ Dugald Stewart, fully alive to the barrenness of Axioms, sought in Definitions for the real foundation. But the same argument applies here. Unless the Definitions are intuitions of the figures and relations defined, they are also barren.' 35 ' Definitions, moreover, must not be arbi- * Thus, from the definition of a cycloid, " the curve described by a point in the circumference of a circle while the circle itself rolls in a 430 PROBLEMS OF LIFE AND MIND. trary, if they are to lead to other than arbitrary con- clusions. We may, if we please, define parallel lines, lines concave to each other ; or define 5 to be the sum 2-1-2. But in this case all our deductions must be consistent with these assumptions ; and we cannot then say that two parallel lines will never meet when prolonged, nor that Sis 3-1-2 or 10-s- 2. The mathe- matician does not begin by assuming the properties of figures, and after defining them proceed to ascertain whether such figures exist ; he begins by ascertaining that snch figures and such relations do exist, and then defines them as he finds them. In other words, Defini- tions are the expressions of the figures, not their foun- dations. With Definitions we can take no step in advance, we can only analyse them* 200. In the Imaginary Geometry of Lobatschewsky andBeltramiwe have indeed a theory of parallels founded on Definitions. Instead of the intuitions really presented to us by the figures, the definitions are made to express relations different from those intuited : they are arbi- trary, and although the deductions from them are con- sistent with these arbitrary premisses, and are therefore logically accurate, they are inapplicable to the real objects given in our Experience. Lobatschewsky's straight line on a plane," we may intuite the truth of Roberval's dis- covery that its area is equal to thrice that of the generating circle ; but we require this to be shown to us through other intuitions, we cannot see it in the definition. * " De la definition du triangle et de la definition de la bissectrice d'un angle, vous ne tirerez pas que les trois bissectrices des angles d'un triangle se coupent au meme point ; ft/out une construction. Le raisonnement, si raisonnement il y a, consiste tonjours dans remuneration des parties de la figure ; ceci est on angle, cek une bissectrice, c'est-a-dire une ligne equi- distante des cotes, &c. De meme le chimiste se dit : j'ai mis la autant d'oxygene, le double dTiydrogene ; j'ai maintenant de 1'eau, done," &c. DKLBOUF : Prdiminaaret de la GdomOric, p. 79. THE LIMITATIONS OF KNOWLEDGE. 431 arbitrary definition of parallelism* is as wide a de- parture from the real intuition expressed in Euclid's definition, as the definition of 5 = 2 + 2 is from our definition of that number. 201. Not only do we find Observation, Hypothesis, Induction, and Experiment everywhere underlying the constructions of Mathematics, as in any other science, we also find that in both the abstractions are all raised from sensibles and extra-sensibles by a simi- lar process. The argument that they cannot have been derived from sensible concretes, because our senses never present them under the forms dealt with by mathematicians, may equally be applied to other sciences : the heavens show no elliptical orbits ; our laboratories show no perfect gases ; our islands and continents show no species. And there is good reason why this must be so. Science deals with conceptions, not with perceptions ; with ideal not real figures. Its laboratory is not the outer world of Nature, but the inner sanctuary of Mind. It draws indeed its material from Nature, but fashions this anew according to its own laws ; and having thus constructed a microcosm, half objective half subjective, it is enabled to enlarge its construction by taking in more and more of the macrocosm. * " Toutes les droites tracees par un meme point dans un plan peuvent se distribuer, par rapport a une droite donne"e dans ce plan en deux classes, savoir : en droites qui coupent la droite donnde, et en droites qui ne la coupent pas. La droite qui forme la limite commune de ces deux classes est dite parallele a la droite donnee." LOBATSCHEWSKY : Etudes Gdomrf- triques sur la the'orie des paralleled j traduit par HOUEL (Paris, 1866), p. 3. In a subsequent work M. HOUEL admits that the conclusions of LOBATSCHEWSKY are in contradiction of Experience but not of Logic JZssai critique sur les principes fondamentaux de la Geometric Elemen- taire, 1867, p. 77. 432 PROBLEMS OF LIFE AND MIND. Science everywhere aims at transforming isolated perceptions into connected conceptions, facts into laws. Out of the manifold irregularities presented to Sense it abstracts an ideal regularity ; out of the chaos, order. The imperfectly straight real lines give place to lines ideally straight. Having to introduce Likeness (equations) amid a manifold Unlikeness, we begin by re- ducing to a first Likeness all the diversities of spaces and numbers presented to Sense, and thus get ideal Space everywhere homogeneous, and ideal Number. And so with the rest. But this recognition of the ideality of Mathematics must not cause us to over- look the fundamental fact that only in so far as the ideals are constructed from reals can they have any validity in reference to reals. Kant teaches that ob- jects conform themselves to our modes of Sensibility, and that it is we who invest them with our forms, which is all we know of them ; and he denies that the things themselves determine our forms. I have al- ready stated in what sense I regard this as true, and in what as false ; it is irreconcilable with the ideality of Science ; 'for were it true that objects received their forms entirely from us, we should find in Nature those very forms which we do not find there, the per- fect circle, the pure gas, the defined species, the histo- logical tissue. These exist, but they exist in our con- ceptions, not in our perceptions. How they arise in conception, as abstractions from perceptions, we know very well ; whereas, if we only saw in Nature what the Mind brought with it, and reflected on objects, we should see the perfect abstractions, and not the imper- fect concretes : and we should see these unaided by Science. THE LIMITATIONS OF KNOWLEDGE. 433 202. Having pointed out the cardinal characters in which Mathematics resemble other sciences, we have finally to inquire if there are any other essential char- acters which would suffice for a genuine difference. There is one character which will be considered de- cisive, and that is the apodictic certainty belonging to mathematical conclusions. Kant in the preface to his Practical Reason declares that we might as well at- tempt to squeeze water from pumice-stone, ex pumice aquam, as to get at necessary and universal truth through experience.* We, on the contrary, have seen that all truth is necessarily true, under the specified conditions ; all truth is universally true if the condi- tions be universalised ; and in these respects Mathe- matics has no superiority over Biology. But, it may be argued, mathematical truths have an universality denied to all other scientific truths, in that they relate to fundamental aspects under which all things are per- ceived by us thus all things whatever are numerable, and all things are extended. But mathematical truths are not true irrespective of conditions ; and their uni- versality is restricted to our universe. The space of geometers is a space of three dimensions ; and many of their truths would cease to be necessary and universal in a space of two or four dimensions. We must say, therefore, that the truths of Mathematics, like all other truths, have their origin in Experience, and are true only of the universe known through Experience. 203. The superior certainty of Mathematics arises from the superior facility with which certainty is reached and exhibited to others. There can be but one certainty * KANT : Kritik derprakticshen Vernunft. Vorrede, p. 107. Werke, iv. VOL. I. 2 E 434 PROBLEMS OF LIFE AND MIND. that of an identical equation, or identical proposi- tion and this admits of no degrees ; it is, or is not. Nor does the equation of condition admit uncertainty, directly the condition which satisfies the equation has been found. The laws of Motion, Affinity, Life, and Mind, al- though in successive degrees less general than the laws of Quantity, are not less exact, less certain. The terms in which they are expressed may be less exact, and their application to particular cases may be far more contingent, than is the application of the laws of Quantity ; but when the laws formulate real relations, and are true, their certainty is unaffected by contin- gencies of expression and application. A general law is raised by abstracting the constants from the variables out of many particular cases we let drop all the special circumstances which individualise each case, and the residuum is the generalised law. When this law has to be applied to some new case, we have to modify it by the reintroduction of such special cir- cumstances as will individualise the case : unless we do this, the law will not hold good, the case will not fall under it. Now it is our very uncertainty respect- ing these special circumstances which constitutes the contingency of the law. Could we be assured, as in mathematical questions we commonly are, of having all the co-operant factors within our grasp, contingency would vanish. In many scientific propositions this condition is fulfilled; the abstract truth- in Biology is as absolute as the abstract truth in Geometry. If this condition is rarely or never fulfilled in concrete Biology, the same must be said of Applied Mathema- THE LIMITATIONS OF KNOWLEDGE. 435 tics. The proposition : " Water is indispensable to the vitality of a tissue," is not less exact, not less certain, than the proposition : " In a right-angled triangle the square of the hypothenuse is equal to the squares of the two other sides." Neither proposition is self-evident ; both have to be shown by experiment ; and when shown, each is seen to be an identical proposition. The intermediate steps through which it is shown that Vitality is never found without chemical change, and that water is necessary for such change may pair off with the steps by which it is shown that in the parallelograms on equal bases, between parallels, the triangles are equal. In both cases a series of identical propositions forms the substance of the conclusions, and the conclusions therefore are equally identical pro- positions. But now observe : although it is indisputable that alcohol in sufficient quantity, or concentration, will with- draw from a tissue in contact with it so much, water as to destroy the vitality of the tissue and although it is an indisputable corollary that drinking alcohol in such quantity must cause a man's death the inference, which to many seems logical, that any quantity of al- cohol must, if not destroy at least diminish, Vitality, is an inference wholly contingent. Every one knows that quantitative differences must have corresponding functional differences. Because a certain quantity of alcohol will destroy a tissue, we are not to conclude that any smaller quantity will do more than disturb its molecular equilibrium, which temporary disturbance may be a positive advantage to the organism. We are here in the midst of indeterminate quantitative 436 PROBLEMS OF LIFE AND MIND. relations, and must call in the aid of experiment to determine whether certain quantities are or are not injurious. Could we once ascertain the precise quan- tities which had precise functional consequences, our treatment of the alcoholic question would be rigor- ously exact. But at present it is no more capable of a solution than an equation of the sixth degree. CHAPTER XV. SOME OBSERVATIONS ON KANT. 204. OUR survey of the Limitations of Knowledge may end here, since to carry it further we should have to invoke the results of an examination into the psychological mechanism, which must be reserved for future Problems. All that now remains is to point out the radical difference between the empirical and metempirical philosophies ; and since all modern Metempirics is either Kantian, or founded upon Kantian principles, we shall best achieve our purpose by confining our criticism to Kant's fundamental posi- tions. No attempt to estimate Kant's work, his posi- tion in the history of speculation, can be thought of here. I have attempted this elsewhere ; and any reader who considers that in the following remarks the constant antagonism seems to imply an undervaluing of Kant's greatness, may be referred to the more gen- eral estimate in the second volume of the fourth edition of my History of Philosophy. 205. Noticeable at the outset is the great general re- semblance between the outcome of Kant's argumentation and the outcome of our own ; whence it may at first appear that Kant, having fought our fight, should be welcomed as a powerful ally. But it turns out 438 PROBLEMS OF LIFE AND MIND. otherwise. He is claimed by our antagonists. The reason of this contradiction it will be profitable to ascertain. First of the agreement : It was his purpose to de- fine the Limitations of Knowledge, and to prove the relativity of all human conceptions. In strict logical result, the Supra-sensible was thus excluded from his philosophy no less than from ours. He did exclude it from the Speculative, but opened a back-entrance for it in the Practical. He taught that our faculties are unable to transcend the limits of possible Experience, and that we only cognise in things, d priori, what we ourselves have placed there. His aim, like our own, he declares to be to revolu- tionise Metaphysics by applying to it the Method of mathematicians and physicists. He affirms, as we do, that intuitions and conceptions make up Ihe sum of Knowledge ; and Intuition is the function of the Mind in the sphere of Sense, while Conception is the function of Mind in the sphere of Understanding, or Judgment. The first has the power of receiving sensuous impressions, the second of knowing by means of these. He shows that " although our pure concepts of the understanding and our principles are independent of Experience, and despite of the apparently greater sphere of their use, still nothing whatever can be thought by them beyond the field of Experience, because they can do nothing but merely determine the logical form of the judgment relatively to given intuitions. But as there is no intui- tion at all beyond the field of the sensibility, these pure concepts, as they cannot possibly be exhibited in concrete, are then totally without meaning." And later on he says : " After all the very cogent proofs THE LIMITATIONS OP KNOWLEDGE. 439 already adduced, it were absurd in us to hope to know more of an object than belongs to the possible experi- ence of it, or to lay claim to the least atom of know- ledge about anything not assumed to be an object of possible experience which would determine it according to the constitution it has in itself. ... . And a still greater absurdity if we wished to have the principles of the possibility of experience considered universal con- ditions of things in themselves." * Not only does he thus clearly formulate the conclusions of the Experi- ential Philosophy, he no less clearly marks the illusions of Speculation when it passes beyond. " It first separates the elementary cognitions which inhere in the under- standing prior to all experience, but yet must always have their application in experience. It gradually drops these limits ; and what is there to prevent it, as it has quite freely derived its principles from itself? And then it proceeds first to newly imagined powers in nature, then to beings outside nature in short, to a world for whose construction the materials cannot be wanting, because fertile fiction furnishes them abun- dantly, and though not confirmed is never refuted by experience." t 206. Now as to differences : In spite of all this, and so much more to the same effect, Kant not only sus- tained the old metempirical tradition, but by his sup- posed discovery of the d priori elements in knowledge furnished the ground for subsequent speculators. Fries, Fichte, Schelling, Hegel, Schopenhauer, and the rest, founded their systems on this. In the great de- bate respecting the origin of Knowledge, whether it is * Prolegomena, 35, 37 (MAHAFFY'S translation, p. 96, 150). t Ibid. 36. 440 PROBLEMS OF LIFE AND MIND. wholly due to Experience, or partly due to Experience, and partly to a higher source, Kant adopted the am- biguous position of declaring that we have a source of Knowledge which is independent of Experience, but that all such knowledge is illusory beyond the range of Experience. His successors fastened on the positive part of his teaching, and rejected the negative. I accept the negative, and reject the positive ; or to speak more precisely, I interpret the positive in another way. In what sense we can be said to bring with us d priori conditions of Knowledge, and even d priori Experience (paradoxical as the phrase may sound) which must determine the result of our individual d posteriori experiences, ha& already been shown ( 22). Kant could not have so interpreted the facts, simply because Biology and Psychology were not sufficiently advanced in his day to suggest such an interpretation. He was hampered by two traditional conceptions, which to his mind were irresistible, namely, the conception of Mind a& an entity, and the conception of Neces- sity and Universality as tests of a truth transcending Experience^ 207. The reader must be reminded that the im- portant point in the following discussion is not whether d priori elements- can be detected in knowledge, but whether those elements were or were not originally formed out of ancestral sensible experiences ; because it is on the decision of this point that the conclusion will rest whether d priori elements prove a supra- sensible origin, and carry a higher validity. 208. Since Kant undertakes to show that the Mind brings with it a fund of d priori knowledge in which TIO empirical influence, personal or ancestral, is trace- THE LIMITATIONS OF KNOWLEDGE. 441 able, we must first see what it is he means by Ex- perience. On this, and indeed on most points, his language is very contradictory. The following pas- sages are, however, such as will generally represent his position : " Experience consists of intuitions which pertain to the Sensibility, and of judgments which are entirely the work of the Understanding." " Experience consists in the synthetical connections of phenomena (perceptions) in consciousness, so far as this connection is necessary " (Prolegomena, i. 22, 23). " The reader has probably been long accustomed to consider experience a mere empirical synthesis of perception, and hence not to reflect that it goes much farther than these extend, as it gives empirical judgments universal validity, [let this be noted] and for that presupposes a pure unity of the understanding which precedes a priori" (Ibid. 26, p. 87, of MAHAFFY'S translation, which occupies the third vol. of his Critical Philosophy for English Readers, 1872.) Thus when defending Experience he is careful to separate it from "a mere aggregate of perceptions" on the one hand, and from a mere sen- suous impression on the other. But in the course of his argument he is frequently found using the term Experience simply for sensuous impression ; and much of his argument depends on this restriction of the term. 209. Observe the contradiction into which he is led. First, he declares that Experience demands the com- bination of sensitive receptivity with logical spontan- eity : the one giving the objective matter, the other the subjective form. " It is the matter of all phenomena that is given to us a posteriori; the form must lie 442 PROBLEMS OP LIFE A3TD MINT). ready d priori for them in the mind" Having thus emphatically stated the two requisites of all Experience, the d priori condition and the d posteriori condition, he nevertheless presents us with this paradoxical statement, that although all knowledge begins with Ex- perience (as just defined), some knowledge is antecedent to and independent of Experience. I do not mean to say that this contradiction is expressly stated by him ; but I do say that such is the plain interpretation of his confused statements. I believe that he unwittingly confounded one factor with the product of two factors, so that after first defining knowledge to be the product of a subjective element and an objective element, calling the one d priori and the other d posteriori, he hence- forward treated the subjective element as if it alone constituted a peculiar kind of knowledge, and not simply one of the factors of all knowledge. It was open to him to call the d priori condition of Experience Knowledge, if he wished it ; but it was not open to him to do this without due warning ; and, above all, it was not open to him after he had expressly defined all knowledge as arising in Experience. The d pos- teriori factor is not less indispensable than the d priori factor. 210. Let me first exhibit the evidence on which Kant is arraigned ; the explanation of how he came to fall into the contradiction may then be suggested. The MOLL led contradiction is that of concluding the existence of d priori knowledge, because Knowledge presupposes an d priori Faculty of Knowing ; in other words, when he argues that before sensuous impressions can be transformed into Experience, they must be moulded by the Mental Forms of sensible Intuition and logical Con- THE LIMITATIONS OF KNOWLEDGE. 443 ception, lie does indeed assert the existence of an d priori element, a condition rendering Experience possible ; but in flagrant contradiction with his own principles he concludes from this that this element is Knowledge. "^Granting (what indeed must be re- jected) the rationality of supposing a Faculty to exist independent of and anterior to its active realisation granting this potential existence of a Cognitive Faculty before there is any Cognition, and of Laws, or Forms, of Experience, before there is Experience we must still separate what he confounds, namely, the Faculty of Knowing, or Laws of the mental organism, from the Knowledge which is the product of those Laws under objective stimulus. On his own showing it is not the Knowledge which is a priori, antecedent to all Ex- perience, but the element added to sensuous impression, supplied from the Mind itself. He has expressly told us that Experience is much more than sensuous im- pression, more even than an aggregate of perceptions. It is a synthesis, " a mode of cognition which requires the co-operation of the Understanding." He says : "Before objects are given to me, that is a priori, I must presuppose in myself laws of the Understanding which are expressed in conceptions d priori. To these conceptions all objects of Experience must necessarily conform" (Preface to second ed. of Kritik). Still this is only presupposing one of the two conditions of Knowledge.* But having identified the product with * " Our nature is so constituted that intuition with us can never be other than sensuous, that is, it contains the only mode in which we are affected by objects. On the other hand the faculty of thinking the object of sensuous intuition is the understanding. Understanding cannot intuite, the sensibility cannot think. In no other way than from the united operation of both can knowledge arise. But we must not on this 444 PROBLEMS OP LIFE AND MIND. one of its factors, he grounds on it a further distinction : " Knowledge of this kind," he says, " is called d priori in contradistinction to empirical knowledge which has its source d posteriori, that is, in experience." He confounds d> priori knowledge with an d priori condition of knowledge, and sets apart this d priori knowledge as something radically distinguished from d posteriori knowledge, although his own definition of the d posteriori declared it to be empirical, and he assumed knowledge to be possible only through the co-operation of this d priori and d posteriori. 211. Many more passages might be given; they would be superfluous. It only now remains to suggest the explanation of how so great a thinker came to com- mit so great an oversight. We must try and place ourselves in his position. The question in the schools had been that of innate ideas. Unless the existence of such ideas could be established, the whole range ol Metempirics would of course prove to be a dream. To prove that we have any knowledge not ultimately re- ducible to sensible experience, it was necessary to prove the existence of data inaccessible to Experience. The school of Locke had indeed presupposed the existence of the Faculty of Knowing, and only asserted that what was Known had an external origin that is to say, the Faculty was called into activity through Sensible Ex- perience. What Locke vaguely presupposed, was de- finitely and expressly brought forward by Leibnitz. This was an important step. " The senses," he said, " although necessary for all actual knowledge, are not sufficient to give us all of it." This is also Kant's fun- account overlook the difference of the elements constituted by each." Kritik : Transc. Logik, i. 88. THE LIMITATIONS OF KNOWLEDGE. 445 damental position. That which the senses do not give is the character of necessity. " Mathematics must have principles of which the proof does not depend upon examples^ nor consequently upon the senses, although without the senses one would never have thought of them. So also Logic, Metaphysics, and Morals, are full of such truths, and consequently their proofs can only come from those internal principles which are called innate." 212. Let me pause a moment here to remark that there is a fallacy in saying the proof of a mathematical truth does not depend upon examples; it does not depend on any number of repetitions, or any variation of the examples, but it does depend on the intuition of the example intuited. Thus 2 + 2=4, is not proved by repeating the formula, or varying the numbered objects; but is proved by intuition of the numerical relations. When Leibnitz says that without the senses we should never have thought of such a truth as 2 + 2=4, he might have added, nor would the truth itself have been demonstrable. All that Leibnitz effected was therefore to render explicit what had been implicit in the argument of Locke. He vindicated the active co-operation of the subjective factor. Kant came, and by his theory of the Mental Forms gave greater precision to this factor. Following Leibnitz he assumed, as incontestable, that the characters of universality and necessity proved the non-experiential nature of every truth which contained them. This position I have argued against at great length, and, I trust, to the reader's satisfaction ; but of course since Kant adopted it we must allow him all that he can deduce from it. I think his deduction 446 PROBLEMS OF LIFE AND MIND. faulty in this respect : granting their d priori char- acter, this does not, by his own showing, establish more than that certain cognitions, derived through Experience, are distinguishable from others by subjec- tive conditions not traceable in the others. Whether any cognition has or has not these characters, it is always the product of two factors, objective stimulus and subjective reaction, the matter and the form. 213. There are three meanings to be assigned to d priori knowledge. First, there is that which belongs to all Deduction, i.e., we have already established by Induction a general principle, from which d priori we conclude some particular result. This meaning Kant explicitly sets aside. He will only recognise as pure d priori that which is absolutely independent of all experience whatever. Secondly, there is the meaning I have already con- sidered ( 22), namely, the organised experience usually termed Instinct which we inherit from our ancestors, and which forms, so to speak, part of our mental structure. In this sense we may be said to be born with a knowledge of Space, with a knowledge of Causality, &c., because although these registered tendencies were originally framed out of sensible experiences, we who inherit the structure so modified, only need the external stimulus, and forthwith the action of that structure produces the predetermined result. The chicken which two or three hours after escaping from the shell captures an insect, puts in action the organised experiences of space, food, &c., which were acquired by remote ancestors. This meaning Kant also rejects, and indeed it would not have served his purpose. " It is quite possible," he says, " that some may propose a kind of pre-formation THE LIMITATIONS OP KNOWLEDGE. 447 system of Pure Reason in which the Categories are neither self-conceived d priori first principles of Know- ledge, nor derived from Experience; but are merely apti- tudes tor thought implanted in us contemporaneously with our existence." And this, which would reconcile his doctrine of Mental Forms with psychological facts, is rejected, because " the Categories thereby lose their character of objective necessity. Nor would there be wanting persons to deny their subjective necessity, though compelled to feel it. Certainly we could never dispute with any one about that which merely de- pended on the manner in which he was organised." 214. Having thus excluded the only two meanings of d priori knowledge which embrace Experience, he is forced to fix on that which is altogether aloof from every empirical element. Only thus indeed could he carry on the traditional doctrine which held Mind to be an entity, mysteriously inhabiting the organism, looking at the external world through the organism, but with visions also of an existence not included in this sublunary sphere. Plato and Leibnitz were consistent in holding this opinion, but Kant was not consistent ; for he had expressly declared that all knowledge had its rise in Experience, although it was not all con- stituted by Experience, since for Experience itself there was needed an d priori no less than an d posteriori con- dition : in other words, all knowledge depends upon material furnished in Sensation, and on form furnished by the Knowing Faculty. Now observe two points : first, the union of d priori and d posteriori is necessary for every cognition ; secondly, and as a corollary, no cognition can be furnished by the Knowing Faculty alone, since Knowing involves a Known, It is because 448 PROBLEMS OF LIFE AND MIND. Kant forgets his own definitions, and speaks of Ex- perience as if it were sensuous impression without the co-operation of the d priori element, that he is led to regard what is logically separable from this d priori condition as if it were really separable, and thus to speak of the Knowing Faculty as pure d priori cognition. 215. Taking his analysis, and accepting Space and Time as the forms of Sensibility, and the Categories as the forms of the Understanding, these forms are only d priori conditions of knowledge, and cannot of them- selves constitute a cognition. By themselves they are as powerless as the external conditions. There never was, and never could be, a cognition constituted out of the forms alone.* That my interpretation is exact may be seen in Kant's letter to Eberhard ( Werke : ed. ROSENKRANTZ, i. 444), wherein he says that the Kritik "allows of no innate or unacquired (unerschaffene) representations, all of them, intuitions and conceptions, are acquired. But there is, to speak with jurists, a primitive acquisi- tion or inheritance, consequently of that also which previously did not exist, and hence belonged to nothing before this act. Such are the form of things in Space and Time, and the synthetic unity of the manifold in conceptions, for neither of these are drawn from objects, as given to our cognitive faculty, but are brought d priori by that faculty out of itself. The first formal condition of the possibility of an intuition of Space is innate, but not the representation of Space itself." Nothing can be plainer ; yet because in the course of his argument he frequently employs the term Ex- * Compare Kritik : Transc. Analytik, 13. THE LIMITATIONS OF KNOWLEDGE. 449 perience in the restricted meaning of sensuous impres- sion, and the d priori formal condition in the impro- perly extended meaning of d priori knowledge, he is led to maintain that the Mind brings with it knowledge wholly destitute of empirical elements. By a similar substitution he sometimes speaks of Intuition and Con- ception as pure forms, formal conditions ; and at others treats them as the products of the forms and the matter, namely, as intuitions and conceptions. Only thus can he instance Mathematics in illustration of pure d priori knowledge. It is obviously nothing of the kind, in his meaning of d priori. The pure formal condition of Space is not, he admits, the representation of Space ; the pure formal condition of Quantity is not any representation of Quantity. Although these forms may accompany, as conditions, every particular experience of space relations, and every particular judg- ment of quantitative relations, they cannot in them- selves be other than pure forms. The conception of causality may be a condition of our judgment, may necessitate the conclusion that every change we ob- serve must have had an antecedent cause ; but it can tell us nothing more, it can throw no light on any particular cause in any particular change. Manipulate the conceptions of Space and Magnitude in the ab- stract how you will, you cannot get out of them any geometrical knowledge, simply because knowledge, geometrical and other, needs sensuous intuition, needs particular experiences to which the d priori forms can be applied. Has not Kant laid it down at the very outset of his exposition that the only mode by which our knowledge can relate to objects is by intuition 1 " To this as the indispensable groundwork all thought VOL. I. 2 F 450 PROBLEMS OF LIFE AND MIND. points. But an intuition can take place only in so far as the object is given to us. This again is only possible, to man at least, on condition that the object affect the mind in a certain manner. . . . By means of sensibility objects are given to us, and it alone furnishes us with intuitions ; by the understanding they are thought, and from it arise conceptions. But all thought must directly or indirectly by means of certain signs relate ultimately to intuitions ; consequently to sensibility, because in no other way can an object be given to us." (MEIKLE- JOHN'S trans., p. 21.) Again : " Pure intuition contains merely the form under which something is intuited, and pure conception only the form of the thought of an object. Only pure intuitions and pure conceptions are possible d priori ; the empirical or d posteriori " (p. 45). 216. How in the face of declarations so explicit is he enabled to propound the hypothesis that we have pure d priori knowledge? It is that besides the unconscious substitution of one meaning for another in the terms employed, he fixes on the characters of necessity and universality as infallible tests of d priori knowledge. At all points this argument meets us. He divides judgments into those which are subjectively valid, and those which are objectively valid. The first are judgments of Perception (Wahrnehmungsurtheile); the second are judgments of Experience (Erfahrungs- urtheile). Although all judgments of Experience are empirical, i. e., have their ground in the immediate sensuous perception, all empirical judgments, he says, are not judgments of Experience. Does this seem con- tradictory ? It is explained thus : over and above the empirical element given in sensuous Intuition, there is THE LIMITATIONS OF KNOWLEDGE. 451 repaired the additional element of conceptions (Begriffe], which have their origin, a priori, in the pure Under- standing ; and under these every perception has to be subsumed before it can be changed into experience. All our judgments are at first judgments of Perception : they are simply the logical connection of perceptions in Thought, and are consequently only valid for the thinker at that particular moment. But afterwards we place them in a new relation, namely, to a world outside the thinker, and insist on their validity for all thinkers and for all time. Hence objective validity and necessary universality are reciprocal notions. "Judgments of experience take their objective validity not from the immediate knowledge of the object (for this is impos- sible), but from the condition of universal validity in empirical judgments, which rest not on empirical or sensuous conditions, but on pure conceptions " (Proleg., 19 ; MAHAFFY, p. 70). He illustrates the two judg- ments thus : When I say the room is warm, I by no means require that every one shall always find this true as I do now. I only express the relations of two sensations to my present self; consequently my judg- ment is not valid for the object : it is simply a judg- ment of Perception. Very different is the other kind, which teaches me that whatever Experience reveals under certain circumstances, it must always reveal to me and to every one ; its validity is not confined to the subject, nor to the particular moment, but to the object for all time. Before a judgment of Perception can become a judgment of Experience, it must be sub- sumed under a Conception. For example, ' when the sun shines on the stone, the stone grows warm/ is a judgment of Perception. No matter how often it may 452 PROBLEMS OF LIFE AND MIND. have been perceived by me and others, it contains within it no necessity. But if I say, " The sun warms the stone," I add to my perception of the effect the conception of cause which necessarily connects the conception of sunshine with that of heat. The judg- ment then becomes universally valid, and is converted into experience. "But how/' he asks, "does this proposition, that judgments of Experience contain necessity in the syn- thesis of perception, agree with my statement, that Experience as knowledge d posteriori can give only contingent judgments ? When I say Experience teaches me something, I only mean the perception which lies in it : for example, that warming of the stone always follows the shining of the sun on it, and thus the pro- position of Experience is always so far contingent. That this warming necessarily follows from the shining is indeed contained in the judgment of Experience (by means of the conception of cause) ; but I do not learn that through Experience ; on the contrary, Experience is first constituted by this addition to perception of this conception of cause" (Proleg., 24, note). 217. Without pausing to inquire how far he has resolved the contradiction here indicated, we may simply note the reappearance of the old confusion of Experience as constituted by an d priori and an a pos- teriori element, with Experience as only d posteriori. He argues that wherever we find the characters of necessity and universality, there we have pure d priori knowledge. Merely noting that on his own explicit statement, constantly repeated, this would only show an element of knowledge, let us ask what proof he offers in support of this argument? It is the old assertion: THE LIMITATIONS OP KNOWLEDGE. 453 "Experience never gives us strict and absolute, but only comparative universality gained by induction, and which asserts that so far we have found no exception. Empirical universality is, then, but an arbitrary or contingent exaggeration from the cases we and others know to all cases ; whereas strict universality is essential to the judgment in which it is found, and points to a peculiar source of knowledge which we have designated d priori." But if universality is essential to the judg- ment in which it is found, and if, as he asserts, it is always found in a judgment of Experience (for without the d priori addition Experience cannot be constituted), how in the name of all Logic can he pretend to show that Experience never gives universality, and that the presence of universality is a proof of d priori know- ledge ? It is like saying that the working of a steam- engine is effected by the steam and the engine, and then arguing that because the engine is powerless without the steam, this proves another source of the power than is to be found in the steam and the engine. By dropping out of consideration the agency of steam, it is easy to show that the engine cannot be the source of steam- engine operation. By restricting Experience to the mere external action of objects on Sense, dropping out of consideration the reaction of the mental organism, it is easy to show that Experience will not suffice. 218. The truth is 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 454 PROBLEMS OF LIFE AND MIND. therefore tried to prove that the Mind brought with it an d priori fund of knowledge. Nay, so resolute was he to break away from the experiential doctrine in re- spect of the origin of knowledge, that he refused to accept the very explanation which was at hand to reconcile his insistance on the d priori element, and his insistance on the limitations of experience I mean the recognition of the Laws of Thought as Laws of the Organism. 219. It is unnecessary to prolong this discussion and to show that when he attempts to prove Mathematics to be d priori because founded on the pure d priori intuition of Space, his argument rests on the confusion of the two meanings of the word intuition, one in which it stands for the primary condition, the Form of Sensibility, and the other in which it stands for the product of that Form and sensible excitation. Blank Space, the pure form, can never generate geometrical figures ; and without the intuition of figures there can be no geometrical propositions. 220. Eejecting Kant's arguments in favour of a source of Knowledge not directly dependent on the Organism and its relations to the Cosmos, and not evolved through Experience which condenses these re- lations, we need not here pause to consider the argu- ments of any other thinker, but may be content with the manifold evidence brought forward in the preced- ing chapters respecting the range and limitations of Research. CHAPTER XVI. THE PLACE OF SENTIMENT IN PHILOSOPHY. 221. OUR survey of the sources and limitations of Knowledge would be manifestly incomplete if it omitted the element of Sentiment, or Emotion, which obviously plays a considerable part in the construction of social and religious theories, and less obviously, but yet demonstrably, in the construction of even common per- ceptions. It cannot therefore be excluded from the data of a Philosophy which aims at explaining the World, Man, and Society. The purpose of Knowledge being to regulate Conduct, and the nature of Know- ledge being that of virtual Feeling, the importance of Sentiment both as regulative and representative is indisputable. None but shrivelled souls with narrow vision of the facts of life can entertain the notion that Philosophy ought to be restricted within the limits of the Logic of Signs ; it has roots in the Logic of Feeling, and many of its products which cannot emerge into the air of exact science, nevertheless give the im- pulse to theories, and regulate conduct. 222. While thus proclaiming the necessity of its inclusion, we must be careful to assign the limits of its range. Appeals are often made to Sentiment, and questions peremptorily decided by it, which are wholly beyond its proper jurisdiction. Rhetoric and Prejudice 456 PROBLEMS OF LIFE AND MIND. are thus called upon to do the work of Reason and Demonstration, in cases where Verification, and not Conviction, is the immediate object of research, where we are not inquiring into the fact of whether a certain conviction exists, but into the ponderable evidence for its truth not whether some men or many men feel disgust or admiration, wrath or compassion, but whether this sentiment which has its personal grounds has also impersonal and rational grounds, such as must coerce every impartial mind desirous of ascertaining the truth. Hence the facts of Sentiment need to be interpreted with the same caution as the facts of the External Order ; and this interpretation is never complete until we reach those limits which are the ultimates of all research. 223. "We live encompassed by mysteries ; we are flooded by influences of awe, tenderness, and sympathy which no words can adequately express, no theories thoroughly explain. These are ultimate facts of Feel- ing which we simply accept. For instance, we have Moral Instincts and ^Esthetic Instincts which determine conduct and magnify existence ; but of these desires for the welfare of others, and this enjoyment of Beauty, we can give no better account than that we find them as facts of human nature ; and no better justification, when questioned, than that their influences are bene- ficial. We can give no better reason why we ought to care for the welfare of others, suffering from their sufferings and rejoicing in their joys, than why sugar is sweet to the taste : they are facts of the human organism ; which facts Psychology and Physiology may approximately explain by exhibiting the factors, point- ing out the observed reactions of the organism under THE LIMITATIONS OF KNOWLEDGE. 457 certain conditions ; but which in a last resort can only be justified by asserting that the facts are so. To use- Cicero's pregnant phrase, " Nature has inclined us to love men : and this is the foundation of the Law."* If a man is insensible to the welfare of others, we can no more convince him that he ought to feel for them, than we can convince the blind man that he ought to see the glories of colour. If a man is insensible to the mystery of the universe ; if his soul, like that of an animal, is unvisited by any suggestions of a life larger than his own, and of any existence where his feelings have no home; if he is blind to the visible facts of evolution manifest in the history of the world and the progress of his race, deaf to the cries of pain and struggle which deeply move his fellows, dead to the stirring impulses of pity which move others to remedy the sorrows and enlarge the pleasures of mankind, by what array of argument could we hope to make him feel what his nature does not feel ? Happily there is no such man. There are only men who feel less vividly than others ; none are wholly without the feelings. And it is on this foundation that a Moral Science is possible ; which proceeds like Phy- sical Science by an exact classification of the observed facts, and their co - ordination. The facts are more complex, the co-ordination is more delicate and dif- ficult ; but their analysis and synthesis, if accurately performed, must yield results of equal validity. 224. All depends therefore on the interpretation of the facts. The inconsiderate way in which Sentiment * " Ubi enim liberalitas, ubi patrise caritas, ubi pietas, ubi aut bene merendi de altero, aut referenda gratise voluntas poterit existere ? nam hsec nascuntur ex eo quod natura propensi sumus ad diligendos homines ; quod fundamentum juris est." CICERO : De Legibus, i. 15. 458 PROBLEMS OF LIFE AND MIND. is suffered to mingle with and pervert rational research, in matters beyond its jurisdiction (as when geological or biological inquiries have been arrested or perverted by alarmed Theology, or national Prejudice) has given rise to an impatient distrust of its admission anywhere in Philosophy. Not only is the physicist justifiably indignant at the idea of his procedures being con- trolled by appeals to feelings which are not directly implicated in his researches, not only does he reject all personal considerations as irrelevant to the 'imper- sonal relations he is considering, but by the violence of reaction against this foolish interference he is swung into the opposite foolishness of altogether denying a place to Sentiment in Philosophy. He insists that Sentiment be excluded from the Laboratory ; and this is wise. But he also often insists that it be excluded from the teacher's chair : and this is unwise. Limiting his conception of Science to its procedures, and not taking into account its social inspiration and its social purpose, he divorces it from Eeligion, and from all con- nection with Sentiment ; although such a divorce at once abdicates the highest position, converting Science into the sheer occupation of an unsocial curiosity, and leaving Eeligion to teachers who pretend to explain the universe without the aid of positive knowledge. 225. No reader of this work will, I presume, so far misunderstand this protest as to suppose that it implies the slightest approval of the appeals to Sentiment in inquiries which directly concern the objective relations of things, and makes personal feelings or traditional dogmas the arbiters of facts. The investigation of fact is one thing ; the interpretation of the significance of this fact in the general system of things, is another. THE LIMITATIONS OF KNOWLEDGE. 459 Sentiment is only admissible when the relations in- vestigated are relations of Feeling ; as, for instance, when doctrines of Political Economy are considered in their social, not in their purely commercial aspects ; the law of supply and demand, being one or the other, according to the indirect or direct point of view. This will become clearer when we appreciate the psychologi- cal principle which necessitates the admission of Sen- timent. 226. We have already seen that everywhere the final test of philosophical interpretation is Feeling. Every demonstration rests on the reduction of inference to sensation or intuition. We have also seen that what is perceived, whether outward or inward, depends for one of its factors on the psychostatical condition of the percipient what is felt and thought being felt and thought thus, and not otherwise, in consequence of the mental state, and this mental state being itself a product of historical evolution. The light of the past mingles with the light of the present. This being the case even with simple perceptions, how much more must it be the case with complex conceptions com- pounded out of simple feelings, and still more with those larger conceptions which constitute Philosophy. 227. If we desire to see the part played by Precon- ception in the construction of conceptions we may advantageously contemplate its action in the abnor- mal cases of Insanity, which are only exaggerations of normal processes. Cervantes, who has admirably painted the wayward logic of the insane, makes Don Quixote fashion a pasteboard helmet, and test its strength by a blow with his sword. The helmet is smashed, and the Don is much displeased at this 4GO PROBLEMS OF HFE AND MIND. fragility of a defence on which he had counted. He thereupon makes another helmet and remains so per- fectly satisfied with its strength that instead of once more putting it to the test he regards it as a helmet of the finest temper.* Again, when he has assumed that Haldudo is a knight, he meets the contradiction that the man is a shopkeeper by asking : what does that matter ? There may be Haldudos who are knights, t 228. To descend from Fiction to Fact, M. Trelat had a patient firmly convinced that he had discovered per- petual motion. All reasoning of an adverse order left him unshaken ; but he was at last brought to confess that if Arago declared him to be mistaken he would bow to that authority. An interview was arranged. Arago, Humboldt, and some others listened with patience to the arguments by which he pretended to demonstrate the possibility of his machine. Arago then explained the mechanical impossibility, and thus con- cluded : " You were good enough to say you would accept my verdict. I give it you, and believe me that all present think as I do that you are in error." The patient was for a moment as if stunned, and then burst into tears. Arago and Humboldt were much affected at the sight, and Trelat had strong hopes that the hallucination was dispelled. But they had not left the the house many minutes before the patient's eyes were dry again, and raising his head proudly he exclaimed : " No matter. Arago is wrong. I have no need of a motor power : my wheel turns of itself ! " J * El qued6 satisfecto de su fortaleza, y sin querer hacer nueva ex- periencia della la diput6, y tuvo por celada finisima de encoje. Don Quijote, cap. i. t Importa poco eso respondi6 D. Quijote, que Haldudos puede haber caltalleros. Cap. iv. J TRELAT : La Folie Lucide, 1861, p. 116. THE LIMITATIONS OF KNOWLEDGE. 461 229. M. Despine had a patient who fancied that poison was constantly mingled with her food. In vain he argued with her, in vain he accumulated proof on proof, her quiet answer was : " You may be right, but I feel that it is as I say, and nothing will ever remove that idea or prove the contrary." Her language ac- curately expressed the fact ; she did not say " I know," but " I feel." She did not invoke material or rational evidence, but the evidence of her feelings.* 230. Examples of this order abound in medical literature ; but we need not seek them there, for our daily experience furnishes an ample supply. No one can have argued against a superstition without noticing an entire insensibility to the plainest evidence when it opposes a conviction. Usually even an exposure of imposture, or the plainest contradiction, has but a tem- porary effect. The staggered believer quickly recovers his old position, and snatches at some suggestion which will explain the contradiction. He may admit impos- ture in this particular case, but 'is sure' there was none in the undetected cases. He cheerfully admits that the facts asserted are in contradiction with all re- corded experience, but he is sure that there " is more between heaven and earth than is dreamt of in our philosophy " and these facts are precisely of this mys- terious class. In truth his mind has received a deep impression ; a conception has been fixed there, and his feelings keep it supplied with energy sufficient to bear down any opposing conception. 231. The doctrine which to one mind seems trans- parently absurd, because it is opposed to the mass of conceptions which have previously been formed, is not absurd, it is simply mysterious, to another mind, and * DESPINE : Psyc/tologie Naturdle, 18C8, ii. 43. 462 PROBLEMS OF LIFE AND MIND. although mysterious is eagerly welcomed because it is in harmony with some conceptions already formed. The mind which to-day sees the absurdity of the doc- trine, may hereafter come to proclaim its truth. The conversion may be either due to intellectual readjust- ment, through the gradual infusion of new conceptions, or to emotional influence gradually changing the at- titude of the mind, and its consequent receptivity. When we see men holding certain theological opinions which are flatly contradictory of their scientific opinions, we are not, on this ground alone, to conclude them to be hypocrites. Each position may be held in perfect sincerity, though not with perfect logicality. The one set of conceptions being in a great measure the expres- sion of their emotions, Sentiment not Reason weaves the web of argument. The other set of conceptions being impersonal, objective, unconnected with emotions, Reason is left free to estimate the objective relations.* 232. A conviction having once been formed, no matter on what evidence, the strength of this convic- tion is derived from the amount of Feeling it engages, and not at all from the ponderable evidence ; so that evidence which to other minds seems overwhelming, will be set aside impatiently with some such remark as this : " That is all very well, but I feel I am right. I can't pretend to answer your arguments, but somehow I am convinced that the case is what I state." Although * STEDTTHAI, mentions the case of a distinguished anatomist who made a pilgrimage to the relics of a saint, and whose edification at the sight of the sacred bones was not in the least disturbed by the fact that he recog- nised them as the bones of an animal. Abriss du Sprachwissfjischa.fi, 1871, p. 228. It seems difficult not to suspect the sincerity of this ; and yet not only is there psychological ground for accepting such a duality of conception, but a similar contradiction, on a smaller scale, is incessantly brought under our observation. THE LIMITATIONS OF KNOWLEDGE. 463 such declarations often betray profound irrationality, the speaker not seeing that the fact of his conviction is one thing, and its truth another ; while the point in question is not the state of his feeling but the state of the case on which he passes judgment ; still such a position is less discredited and less discreditable than it would otherwise be, owing to our general recognition of the truth that many of our judgments were formed upon evidence so complex and evanescent that we cannot now recall it. When conclusions have become organised in our minds the data are usually quite irrecoverable ; yet we may be fully assured that originally the evi- dence was present, and could be again produced were ample time and opportunity allowed us. If we have a rational conviction, although we cannot produce the grounds on which it rested, and cannot therefore force it upon others, why are we to scout the declaration of the man who relies on a conviction for which he can assign no reasons ? Why do we treat our conviction as rational, and his conviction as irrational ? It is because we assume that our forgotten evidence, if produced, would not simply justify our conviction, but would harmonise with the evidence which is now present ; whereas he resists the evidence produced, and relies on evidence which is not producible. Every investigator may have the consciousness of having carefully ex- amined facts before he adopted their results ; and sus- pects, generally with justice, that those who manifestly disregard the evidence now before them, because it con- tradicts their conclusions, were not very scrutinising in their examination of the facts on which their conclu- sions were originally formed. No one who has been long occupied with investigating a subject is unaware of 464 PROBLEMS OF LIFE AXD MIND. the growth of convictions stronger than the available evidence seems to warrant. It is this experience which cannot find its accurate expression that justly endows an investigator with authority. But no worker hopes to impose his conviction on his contemporaries in the face of available evidence which contradicts it; and all sincere minds are alive to the huma-n infirmity of grasping at evidence which harmonises with our views, rejecting those which oppose it, or seeking to nullify their force by extraneous considerations an infirmity not less chargeable on philosophers than on ordinary men. 233. Here again we see how needful it is to make clear to ourselves the kind oi evidence on which we rely. People will oppose the rational interpretation of admitted facts on the ground that such an interpre- tation is in " contradiction to their holiest instincts." This rejection or instinctive repulsion may be emi- nently wise, or eminently foolish. It is foolish when in the hardihood of ignorance men rely on Instinct as necessarily unerring, having a higher source than Reason ; for the fact is that instincts are variable, and often fatally misguided. The instinct which urges the moth into the flame, or which makes the insect deposit its eggs in a fetid plant when that plant has the odour of putrid meat (whereby the eggs are hatched in a nidus where they perish from want of food), these are but two of the many examples of Instinct fatally mis- leading.* Nor are our instinctive judgments to be * " I one day met with a curious example of failure of instinct, which, by showing it to be fallible, renders it very doubtful whether it is any- thing more than hereditary habit dependent on delicate modification of sensation. Some sailors cut down a good-sized tree, and, as is always V \ THE LIMITATIONS OF KNOWLEDGE. 465 trusted. The judgment of the child that the moon may be grasped by its tiny outstretched hand, the judgment of the ordinary man that the redness of the rose is a part of the rose, and present in the darkness where there is no light .reflected from it, no eye to see it, these and other judgments teach us how little we can rely on Instinct, even in simple cases. To any one who objects to some social change, not because it is demonstrably inconsistent with social welfare, but because he infers that it is so " since it excites his instinctive repulsion," we may justly ask : What are the experiences organised in that repulsion 1 You feel that the proposed change will be injurious it excites images of alarm ; but what is the origin of your feeling? upon what social induction does it rest 1 ? what guarantee have you that the images of alarm are not unreasonably excited. When he can state the grounds of his repulsion, as we can state the grounds of our proposal, there is a weighing of evidence pos- sible. But the mere repulsion, though not to be disre- garded, is only a warning, it is not evidence. It may indicate the presence of some condition which ought my practice, I visited it daily in search of insects. Among other beetles came swarms of the little cylindrical wood-borers and commenced making holes in the bark. After a day or two I was surprised to find hundreds of them sticking in the holes they had bored, and on examination dis- covered that the milky sap of the tree was of the nature of gutta-percha, hardening rapidly on exposure to the air, and glueing the little animals in self-dug graves. The habit of boring holes in trees in which to deposit their eggs was not accompanied by a sufficient instinctive knowledge of trees which were suitable or trees which were destructive. If, as is very probable, these trees have an odour attractive to certain species of borers, it might very likely lead to their becoming extinct ; while other species to whom the same odour was disagreeable would avoid the dangerous trees, and would survive and be credited by us with an instinct, whereas they would really be guided by a simple sensation." WALLACE : The Malay Archipelago, 1869, ii. 275. VOL. I. 2 G PROBLEMS OF LIFE AND MIND. to be taken into account ; but unless it spring from one of the deep-seated instincts which express the moral experiences of the community, it is no more than an indication ; and even then, we must bear in mind that our moral experiences widen with advancing civilisa- tion, the deep-seated instinct of the community of to- day will not correspond with the enlarged social ex- periences of to-morrow, for there is evolution of the Moral Instincts no less than of the Rational Judgments : we learn to feel differently respecting social relations, as we learn to think differently of the cosmical rela- tions. The boast of one age may become the infamy of another. Granting, therefore, its due weight to Sentiment and to Conviction irrespective of producible evidence, we must still say that any proposition opposed by these ought not to be rejected until their sources and range have been scrutinised. Scrutiny will often detect that the repulsion is due to some unconscious desire to preserve the existing order, because agreeable to our prejudices or interests ; sometimes it is due to confi- dence in an old custom, or a venerated teacher; and then we may ask : On what was the custom founded \ What means of knowing the truth had the venerated teacher \ and what part did his feelings play in inter- preting the evidence '( 234. The legitimate influence of Sentiment in deter- mining Belief, and thus regulating conduct, is a delicate question. Theologians have not been wrong in ascrib- ing Faith and Incredulity to moral predispositions, and in affirming that religious conviction mainly depends upon religious feeling. But they have been wrong in assuming that religious feeling can be reached by argu- THE LIMITATIONS OF KNOWLEDGE. 467 ment, or created, where it is absent, by an effort of the will. It is not true that a man can believe or disbe- lieve what he will. But it is certain that an active desire to find any proposition true will unconsciously tend to that result, by dismissing importunate sugges- tions which run counter to the belief, and welcoming those which favour it. The psychological law that we only see what interests us, and only assimilate what is adapted to our condition, causes the mind to select its evidence. 235. Further, in respect of religious convictions we must distinguish between the personal or subjective aspect, and the impersonal or social aspect between the truth which is a law to the man himself, and the truth which is a law for the community. The feeling which determines the actions of the man is valid for him : what he feels, he feels; what he thinks, he thinks. But this may not be communicable to others, cannot be made guides for them. For communicable truths, two things are requisite the possibility of showing them in their objective relations, or by intelligible symbols, and the mental state ready to grasp these. The beauty of a statue is felt by twenty spectators in a somewhat similar manner, owing to a similarity in their minds, and for all these it would be a true proposition to affirm " this statue is beautiful." It would not be true for other spectators, insensible to the aesthetic charm. Here is a truth which in the nature of things is limited : we may generalise it, and affirm that many minds, perhaps the majority, will feel this pleasurable emotion ; but we never assume that the truth represents an in- variable relation for all minds, like that of parallel lines, or the composition of water, which express objective 468 PROBLEMS OF LIFE AND MIND. relations that are invariable and undisturbed by any subjective variations : these latter are communicable truths which all minds must apprehend when the terms are distinctly presented. No one will say that a per- sonal incommunicable truth is less certain than an impersonal communicable truth. If I say " there I see an apple," this expression of a subjective fact requires no evidence ; but if it be affirmed as an objective fact affirming the present existence of the apple and not merely my present feeling, evidence is needful. I can communicate to others the fact of my feeling, but I can only communicate to them the fact of the existence by placing their senses in relation to the object. What I see may be no apple, but an imitation in stone. My inference from the visual sensation may have been false ; and my affirmation in such a case would be subjec- tively true, objectively false : true, in that I had the visible feeling which an apple would excite; false in that I concluded from this to the existence of an apple there present. Nor would the testimony of fifty thousand people all affirming that they saw the same apple, all declaring that what they saw really was an apple, add one tittle of objective validity to my assertion. This is a paradox only to those who do not appreciate the nature of evidence. Because we habitually find our inferences confirmed, or corrected, by the testimony of others, we fall into the mistake of counting testimony instead of weighing it, and suppose that many specta- tors are more to be trusted than one ; whereas it is not the multitude of observers but the variety of the means of observation which gives value to their testimony. The concurrent testimony of fifty thousand persons would only prove that they were visually affected in THE LIMITATIONS OF KNOWLEDGE. 469 the same way, and had inferred the same thing ; and unless these observers were placed under different con- ditions, fifty thousand observations are no better than five. A miracle performed in the presence of a multi- tude has no greater credibility than the same miracle performed in the lonely chamber of a solitary, unless some among the multitude have sources of experience on which to ground their inferences, which were not open to the solitary. When wonder-workers ask for our belief because their assertions are certified by hundreds of respectable witnesses, they should be told that neither numbers nor respectability have scientific weight, when all the witnesses are under the same dis- advantages respecting the reduction of their inferences to sensations ; the same assertion repeated many times, however varied its expression, is not made more credible oy repetition. All that the testimony of a multitude of witnesses really amounts to is that they had certain sensations, from which they inferred certain correspond- ing events. 236. During M'Clure's Polar Expedition the watch one night saw a bear on an iceberg. He called to his mates, and they having armed themselves, cautiously approached the spot where the bear stood. To the astonishment of all, this visible bear rose in the air, and flew away. They had mistaken an eagle for a bear ; yet not one of them had doubted his inference from the optical sensation common to them all. Had they not alarmed the eagle, or had the spot been inaccessible, they would all have sworn sincerely that they had seen a bear. Would a million of such witnesses have rendered this statement more credible ? But now sup- pose the sailors to have returned to the ship because 470 PROBLEMS OF LIFE AND MIND. they found it difficult to approach this bear, and only two of them had remained behind hoping to find a more accessible path ; one of these remaining on the watch while the other seeks a path, presently the watcher sees the eagle rise and fly away ; and on his return to the ship he tells his companions what he saw. They may or may not believe his statement, according to their trust in his veracity or the intensity of their previous conviction ; and if now the other sailor re- turns with the eagle which he has just shot, the con- viction is complete. 237. All Knowledge, being virtual Feeling, is only communicable through Feeling. A man may commu- nicate to me the fact that he has a sensation, a per- ception, or an emotion, but he can only awaken similar sensation, perception, or emotion in me by placing me in similar conditions, objective and subjective. He may tell me that a certain fruit has a sweet taste, and I may believe this statement to be objectively valid ; but I must myself taste the fruit before I can share his feeling. He may tell me that he has a misgiving, but that misgiving can only be awakened in me by a pre- sentation of its grounds. There are degrees of com- municability. If I am told by some one that he has seen a dog, I have so distinct an image raised by that word that I can understand his feeling, and in a sense share it. If I am told by the same person that he has seen a gangrened limb, the absence of experience will make me very imperfectly understand him. If he tells me he has had a bilious attack, my apprehension is vague. If he tells me that the summer dawn fills him with re- ligious joy, and an autumnal evening with religious awe, my apprehension is still more vague. I too may THE LIMITATIONS OF KNOWLEDGE. 471 have many times been touched by the tender lights of a summer dawn, but unless there is some communicable mark by which these reactions of feeling can be seen to resemble those reactions in him, our two experiences remain personal, subjective, incommunicable. Hence it is that Sentiment only passes into Science when it is capable of being translated into objective signs. The sensations of colour and sound must be translated into vibrations, and then the reactions of Feeling are measured with reference to their objective vibrations. Every variety of tone, however distinct to Feeling, was a personal fact of no value to exact Science, until it thus became interpretable through its objective sign. This connection once established, Science had its instrument. Every single tone had its dynamical sign every sub- jective fact its correlative external fact and then what- ever could be deduced from dynamical laws of vibra- tion was inferable of Sound ; thus were discoveries made by mathematical analysis which could never have been approached through analysis of Feeling. 238. In conclusion, we may say that the part played by Sentiment in Philosophy is very large, and is admir- able, or the reverse, according to circumstances. It is necessary and admirable as an inspiration, when duly controlled by verification. It is admirable, and its jurisdiction is final, when feelings form the subject- matter of the debate. It is disastrous when it takes the place of verification and substitutes personal for impersonal relations. Among the curious features of our mental organ- isation must be noted that by which on all subjects of immediate practical importance we always proceed at once to verify any conjecture we may have formed, 472 PROBLEMS OF LIFE AND MIND. whereas on subjects of speculative importance we are too impatient to await this control, and in our eager- ness for an explanation readily accept conjectures as truths. The anticipatory rush of thought prefigures qualities and foresees consequences ; instead of paus- ing to ascertain whether our anticipations do or do not correspond with fact, we proceed to argue and to act on them as" if this mental vision were final. Native indolence unchastened by repeated failure, and native impatience unchecked by caution, are sustained by the energy of our confidence in what we think. Even a false explanation is preferred to the unrest of doubt ; and a plausible explanation is so gratifying to the feelings by quieting this agitation of unrest, that we cling to it in spite of adverse evidence. Who has not observed, even in himself, the eagerness with which some argument is snatched at, and some statement credited, when these seem to confirm his own view of the case ? To submit our conclusions to the rigorous test of evidence, and to seek the truth irrespective of our preconceptions, is the rarest and most difficult of intellectual virtues. How then can truth be decided "? What are the tests of certitude \ These questions must be examined in the next Problem. Hitherto we have examined the range and limitations of Knowledge, and have only touched incidentally on the nature of Certitude ; hence- forward we shall have to apply the principles here expounded. END OF THE FIRST VOLUME. B 7 THE LIBRARY UNIVERSITY OF CALIFORNIA Santa Barbara Goleta, California THIS BOOK IS DUE ON THE LAST DATE STAMPED BELOW. 20m-3,'59cA552s4)476