^mmll Wimvmxi^ ^toirg THE GIFT OF Sy^rY^^irrr^r'^r^^ \\X/>r* i\..3.5^.\:i ' ^.^.jmjiM. 7583 Cornell University Library BD161 .P54 Dynamic foundation of Icnowledge, by Aiex olin 3 1924 029 028 905 Cornell University Library The original of tliis book is in tine Cornell University Library. There are no known copyright restrictions in the United States on the use of the text. http://www.archive.org/details/cu31924029028905 THE DYNAMIC FOUNDATION OF KNOWLEDGE THE DYNAMIC FOUNDATION OF KNOWLEDGE ALEXANDER PHILIP M.A., LL.B. LONDON KEGAN PAUL, TRENCH, TRUBNER & CO. LTD. BROADWAY HOUSE, 68-74 CARTER LANE, E.G. 1913 PREFACE It is now a long time since the writer of the follow- ing pages first thought of a dynamical interpreta- tion of the concept of Matter. After some years of consideration and discussion he expressed his views in print in an essay entitled Matter (jLtvi En&rgy : Are, there two Real Things in the Physical Universe? This essay was pubhshed in 1887. A second essay was pubhshed in 1897 under the title, The Doctrine of Energy: A Theory of Reality. In these essays he maintained that the scientific concept of energy adequately explains the pheno- mena of nature, and that the inconsistent concept of material reality should be finally abandoned. The question referred to has made great apparent progress since the date first mentioned above. The foolish abuse with which in certain quarters such ideas were then greeted has disappeared. They might now almost be called popular. In philosophical journals they are constantly referred to, whilst as integral parts of scientific theory they are accepted and employed by many high authorities. The successors of some who looked upon them with dishke and derision seem even disposed to claim them as their own. vi PREFACE The present writer might perhaps regard these facts as indicating that he started his speculative journey along the right road. Possibly it may also be thought that there is now no further need for continuing the inquiry. To him it seems that such a view would be erroneous. We cannot say that the goal has yet been reached or that a foundation of definite concepts has yet been surely laid for physical knowledge. The elusive developments of recent scientific theory in various directions appear rather to render the task of seeking such a foundation more imperative than ever. The highest powers of mathematical analysis — the necessary instrument of physical research — do not imply a clear definition of fundamental con- ceptions. The writer had occasion in his first essay to draw attention to obvious contradictions in the definitions of Matter and Force as employed by scientific writers of the time. Much more fully the same subject was dealt with in one of the ablest essays which the nineteenth century produced, the weU-known treatise on the Concepts of Physics, by Mr. J. B. Stallo. Physicians and mathematicians sometimes seem to resent such criticisms. But they are at present essential to the attainment of truth. Amongst metaphysicians, again, the apprehension of the instrumentary conceptions of Physics is some- times almost incredibly crude and contradictory. Here also investigation and careful definition are very much required. PREFACE vii But criticism must be followed up by construction. This, unfortunately, Mr. Stallo hardly attempted, and amidst the flux of theories it might perhaps seem as if such an attempt must be hopeless. The present writer is convinced that there is no ground for despair, but that if we could arrive at the true source and origin of our Cognitions of the External, our physical concepts would become as clear and definite as those of mathematics. He beheves, indeed, that recent advances in physical theory offer a very promising key to the solution of the problem. Archimedes asked but a fulcrum that he might move the World. Such a fulcrum or basis for our conceptions of Nature is what we want to-day. In the following pages the writer offers a small but sincere contribution to such an inquiry. He is conscious that his essay is necessarily very im- perfect. A more serious fault in the eyes of some may probably be that he presumes to investigate ideas which competent students of science often accept or imagine that they accept without question. But that cannot be helped ; and he must leave the arguments by which he endeavours to support his position to speak for themselves. An important confirmation of the views suggested in the following pages is to be found in the theory of the nature of language as an expression of action. The year 1887, in which the writer's first essay was published, was also the year in which the late Professor Max Miiller's work on The Science of ThougM first saw the light. Well aware that his viii PREFACE views were widely questioned, but with a serene conviction of their ultimate justification, the great philologist put his theory before the world. The present writer is not to be understood as accepting Max Miiller's doctrine in its entirety, but he is satisfied that it contains an important element of truth, the value, of which as an aid to clear con- ceptions of the External World he has endeavoured to point out. The subject discussed in the following pages ia- the most practical of problems. " Man may do many things," said Goethe, " but he may not live at random." The aphorism is as true of the race as it is of the individual. The sailor as he leaves the shore behind must always have some datum from which to make his reckoning, and when at length he ventures on the boundless ocean he must have a compass on board. It is the same with those who would navigate the ship of Science. A cosmography served them for long. Nothing but a true theory of cognition can save them now. The races of Europe for centuries made no intellectual progress. Had they delayed any longer than they did to assimilate the Copernican Astronomy they were doomed. If they fail now to solve the problem of knowledge they will perish. Without some objective and evident standard of truth. Science cannot be distinguished from quackery, nor fact from fad, nor law from Mcende. The danger of such confusion is real and imminent in Europe and America to-day. PREFACE ix As M. Paul Bourget has well remarked, " The true synonym of Evolution is not change but perman- ence. A being in evolving seeks its own conservation by adapting itself to its environment. When it ceases so to evolve it dies." Agnosticism claims to be the creed of Science. Originally the claim had reference only to the super- natural. It threatens now to invade the proper domain of natural knowledge. Yet if knowledge is unattainable Science cannot exist. Already on every hand the urgent need is felt for some definite criterion of truth. We find mathe- matical knowledge declared to be empirical. The law courts have recently decHned more than once the duty of distinguishing between medical science and quackery. In economics what are scientifically obvious fallacies form the creed and teaching of thousands. In poUtics the socialist is perpetually being duped by the faddist. If dynamics has as yet escaped, it is only because it is constantly protected by practical tests. Impres- sionism, having conquered Art, seeks to embrace Science, and is already enveloping Education. Metaphysics is a welter of despairing compromises. CiviMsation moves rather towards a chaos than towards a cosmos. Surely, therefore, the task attempted in the following pages — whether it be successfully accomplished or no — is at least one which should engage the attention of every thought- ful man. CONTENTS PEBFAOE .... I. THE SENSIBLE WOBLD n. THE ATFIEMATIVE JUDGMENT m. THE NE0ESSAB7 F0ST17LATE IV. ACTIVITY .... V. THE OBIQINS OP METAPHYSIO VI. BEAIiISM .... Vn. THE POTENTIAL AND THE ACTUAL Vm. THE MIDDLE AGES IX. THE RETURN TO NATURE X. SENSATIONALISM AND INTELLECTUALISM XI. THE DETECT OF REALISM AND IDEALISM Xn. THE NATURE OF KNOWLEDGE xm. CAUSATION XIV. REASON AND CAUSE XV. THE TRUE ORIGIN OF THE POSTULATE XVI. THE IDEA OF MATERIALITY XVn. BXTENSITY XVm. THE TWO ACTIVITIES OF THE ORGANISM XIX. THE LAWS OF DYNAMICS . XX. THE IDEA OF ENERGY XXI. THE FORM OF SPACE XXn. THE DEFINITIONS OF MATTER XXm. THE RELATIVITY OF DYNAMICAL KNOWLEDGE xi 1 9 15 20 29 35 44 47 50 53 62 65 75 80 83 86 95 102 114 122 136 142 146 Xll CONTENTS CHAP. XXIV. XXV. XXVI. xxvn. XX vm. XXIX. XXX. XXXI. XXXII. xxxni. xxxiv. XXXV. XXXVl. XXXVII. xxxvin. THE TWO ACTIVITIES OF THE OEGANISM AGAIN DIS TINGUISHBD THE AXIOMS OF GKOMBTBY . THE STRTJCTUEE OF THE OEGANISM WHAT WE KNOW SCIENCE AND REALITY NATITRE AND AET ETHICS .... THE SCIENCE OF LANOTTAGE . MEANINGS THE UNITY OF KNOWLEDGE . KNOWLEDGE AND OPINION THE GENBEAL AND THE SINGUTLAE THE DYNAMIC THBOBY APPLIED 10 ECONOMICS THE DYNAMIC THEOEY APPLIED TO EDUCATION THE DYNAMIC FOUNDATION OP METEICAL STAND- AEDS PAGE 156 162 175 191 197 206 208 211 229 237 246 260 277 305 312 THE DYNAMIC FOUNDATION OF KNOWLEDGE THE SENSIBLE WORLD The sensible world is mutation — a constant pro- cess of change. We are, indeed, accustomed to admit and cannot ignore the fact of constant change and movement amongst the objects of sense. But those objects themselves, or some of them, are, we think, continuously identical things — compara- tively steadfast and abiding. The existence of such fixed points is, indeed, necessary to the recognition of change. We can only know differences by contrast. Without the opportunity of comparing the mutable with the constant the notion of change or movement could not arise. Without a relatively fixed datum the perception of change would be impossible. It is thus that we perceive incessant change amidst the objects of sense. But what we do not at first realise is that the sensible is itself mutation. 2 THE SENSIBLE WORLD It consists in changes occurring in something else which undergoes these changes. And in the primary fact of sensation we are conscious not at all of that which changes, hut solely and only of the change. When we observe a man walking, or the branch of a tree waving in the air, we perceive both the object which moves and its motion. Such move- ments of the objects of sense are, so to speak, facts superposed upon these objects, which themselves constitute the sensible datum of experience. But that datum itself is a transmutation, and that trans- mutation is the fundamental starting-point. We cannot in its case perceive also and in addition the thing which is transmuted. The fixed datum with which movement is con- trasted is, in fact, always only relatively fixed. But in the case of our primary experiences we cannot directly advance to the perception of that further datum, the changes in which constitute our sensa- tions. We are, therefore, apt to overlook the fact that the sensible is nothing but mutation. No doubt many of the main elements of the sensible phenomenal world exhibit great perman- ence and stability. But that does not at all affect our argument. Our point is, not that phenomena are changeable, but that they are changes. Their very nature and essence is mutation; their very permanence is a permanence of change. Take the case of a ray or pencil of light. It is, in fact, a rapid stream of undulations ; but it appears to vision a rigid and motionless beam. Accepting THE SENSIBLE WORLD 3 this as a unit we may, by putting in motion the luminous source from which it issues, cause visible movement of the ray itself. In such a case vision perceives not merely the movement of the ray but the ray itself which moves. But viewing the ray as a compound of wave-motions, we perceive only the sensible result of the undulations and not that which undulates. It is, indeed, possible, by a more minute examina- tion, to analyse and disintegrate the ray, and perhaps to discover what we think are the constituents in which the undulation occurs. But that only carries us one step further back in the chain of data. It lets us understand that vision itself must be regarded as the result of undulations transmitted to and affecting the sensorium. It is the existence of such movements which gives rise to the sensation ; and in sensation, therefore, it is clear that we are not conscious of the thing which changes, but that, on the contrary, the sensation is but the subjective aspect of what must be regarded objectively as a process of transmutation. We might take as an illustration a waterfall. Apart from variations in the volume of the stream, the appearance of the fall at a given point is that of a constant and permanent object, yet we know that it is composed of rapid and incessant movements, and that its apparent constancy and rigidity are due to the constancy of the process of transmutation or motion in which it consists. We repeat, therefore, that the sensible appearance 4 THE SENSIBLE WORLD is our fundamental datum ; and that, consisting as it does in transmutation, we perceive in this case the transmutation merely and not that which is trans- muted. Even those sensible appearances which seem comparatively fixed and immutable are, in truth, mutations, and their apparent constancy is, in point of fact, a constancy of change. All reflective thought conducts to this conclusion. When I consider the earth, and the heavens they appear to be a system of objects moving in regular and periodic harmony around a centre fixed. Some wanderers are observed, but these are gradually and more and more effectually assigned to their appointed places in the general order. Yet step by step man has been driven from the security of such a view. The periodicity and the harmony remain, but the fixity is proved delusive. We are successively dislodged from every fulcrum until we are forced to recognise that there is mutation every- where ; that fixity and movement alike are only relative terms, and that the only constancy to be found is a constancy of change. When I examine the details of the sensible pre- sentation I am driven to the same conclusion. I experience a sensation of sound ; I say I hear a trumpet. But the statement is a veiled inference. I hear merely the sound which I associate with the thing or mental idea called a trumpet. And that sound, when I examine further, is resolvable into an undulation of particles, a vibration of the drums of the ear or of the nerves which lead from them to the THE SENSIBLE WORLD 5 sensorium. And what I feel, what constitutes the sensation of sound, is evidently the undulation itself, not the particles which undulate, their presence, if unagitated, giving rise to no sensation. I do not feel my organism when in its normal state. I feel merely the changes or transmutations which take place in the normal course of change. Sensation is not sensation of thing changing and of change. It is simple consciousness of change. The same exciting cause may produce altogether different sensations, according to the portion of the organism affected. Thus an electrical current may produce the sensations of flashes of light, distinct sounds, phosphoric odours, a peculiar taste, or a feehng of pricking, according to the particular sensory nerve to which it is appHed, (Carpenter, Mental Physiology, ch. iv. p. 132.) To take a simpler instance : the pressure of the hands may produce a tactual sensation if applied to a tactuaUy sensitive surface, and a sensation of colour if applied to the retina. What I feel is the change, and the nature of the feeling depends on the nature of the change produced. It is only if the transmutation reaches the sensorium that sensation is produced at all. However much it may affect any other portion of the organism, even of the nervous system, unless it extends to the particular portion of that system where the sensory afferent nerves originate no sensation is experienced, and when at length the process does reach the sensorial 6 THE SENSIBLE WORLD centre it is only in the form of a change in its con- dition. A sensation cannot, therefore, be in itself a real thing. Again, if a particular form of transmutation con- tinues without intermission for a considerable period, the organ appears to adapt itself to the new con- dition; the very constancy of the change gives it the character of immutability, and sensibility simultaneously diminishes. In proportion as the change becomes an established condition so does the sensation disappear. (Carpenter, Mental Physi- ology, p. 138.) The organism itself, as a living unit, is in like manner a constant process. In its normal operation that process does not involve sensation. It is the condition precedent to sensation. The organism is like a well-fitting garment. I do not feel it at all. Disturbances or interferences with the regularity of this process originate sensation, but the normal process is unfelt. Yet without the maintenance of this process life and sensation would cease to be. In reference to the organism, sensation is not merely consciousness of change ; it is consciousness of changes in the normal process of change. To use a dynamical simile, it is only acceleration of the normal motion which is felt. The most fixed and permanent of the objects of sense we are accustomed to call material bodies, and we are disposed to believe and affirm that they at any rate, or some of them, are comparatively im- mutable. If their form and condition vary, at THE SENSIBLE WORLD 7 least their substance and quantity remain un- changed. But matter itself is but a process. Its solidity and impenetrability are the phenomenal manifesta- tions of the constant operation of what we are accustomed to call cohesive force. A force, how- ever, is but a rate of transmutation. Let this dynamic process, so constant and invariable, cease to operate, and Solidity, Resistance, Body, Matter are no more. Fundamentally the reality of matter is based on its indestructibility, on the fact that we cannot by any act of ours increase or diminish its quantity. But that just means that, however much we can alter the current of change in those transmutations which are superinduced upon the physical process in which materiaUty consists, we cannot afEect or alter that process itself. We cannot alter the operation of cohesive force or of gravitation. Hence we cannot alter the constancy of the physical phenomena which depend upon their operation. Some thinkers, whilst recognising the mutability of the sensible, have endeavoured, nevertheless, to extract or abstract from its data the primary permanent abiding features of the object world, and to find in these the main elements of reality. But the permanencies and constancies which they thus extract are but permanencies and constancies of change, and more than one critic has had no diffi- culty in showing that it is, therefore, vain to hope that we should be able to extract from, or discover 8 THE SENSIBLE WORLD in the sensible, any element which is not in essence a mutation. The sensible world in one word is a process of change, and if we are ever to find the real and the immutable, we must transcend the limits of the world of sense. II THE AFFIRMATIVE JUDGMENT The foregoing considerations do not disturb the ordinary thoughts or actions of any human being. Every one of us grows up with the tacit assumption and belief that he is surrounded by a more or less permanent and independently real world which environs and contains the more or less permanent and real organism which he calls his body or him- self. Sensations he regards as resulting from the action and as exhibiting the qualities and features of the objects of which the world is composed. Such beliefs are unaffected by the constant changes which the sensible environment obviously undergoes — unless, indeed, that they are rendered clearer and more definite by the contrast. This continuous practical belief in a permanent real world has lately received the not inappropriate name of the Affirma- tive Judgment of the waking consciousness. This incessant affirmation of reality is an act of the mind. Whatever may cause or constitute the reality which sustains the world of sense, it is at least certain that the affirmation of reality is an 9 10 THE AFFIRMATIVE JUDGMENT intellective act. Knowledge, in short, is a system of mental afi&rmations. Reality, as contrasted with the things of sense, themselves mutable and un- real, is erected for us by an intellectual operation. What, then, exactly is it that we predicate in such mental act of affirmation ? We constantly affirm the continued existence, apart from sensation, of things in which qualities productive of sensation reside, which have causative efficacy, which resist our activity in definite forms whence we derive our conceptions of body and space. Perception, so called, is, in fact, a projec- tion of these qualities, and our system of perceptual cognitions is a structure composed of such mental affirmations. Sense may be actual ; but it is of something beyond and behind the actual that reality is affirmed ; and such affirmation is al- together different from the mere identical proposi- tion that sensation is felt. The world, then, which surrounds us, and which we in the first instance describe as a presentation of sensation, is very imperfectly represented by such a view. When I call the object in front of me a tree, I think into it a great deal more than what is given in sense. A strip of brown colour surmounted by some green is the total visual datum. In speaking of that as a tree, I not only think of the various changes which these sensations might undergo in conse- quence of my own actions ; I think also of the tree as a thing — a potent dynamic entity asserting itself THE AFFIRMATIVE JUDGMENT 11 as a permanent reality, and containing within itself powers of growth and change. ^ In whatever I ultimately conceive that the reality of the tree consists, it is at least clear that I think of it as something altogether different from the im- mediate sensation to which it gives rise — that it is, in fact, not a sensible presentation, but a thing, the existence of which is the object of an assertion or affirmation by my mind. When, therefore, I say that the affirmative judg- ment fills my world with things, I imply that for me the reality of the world around is something very different from the complex of sensible pre- sentations whose undoubted actuaUty appears at first glance to constitute them, by their very immediacy, the most real constituents of experience. In order, therefore, to attain to clear ideas on this subject, it is evidently of first importance to dis- tinguish between the affirmations of thought and the data of sense. What really is the contribution of sense can be 1 Dugald Stewart well illustrated the point upon which we insist by the consideration of what a book reaUy ia. " In looking at a page of print or of manuscript, we are apt to say that the ideas we acquire are received by the sense of sight, and we are scarcely conscious of a metaphor when we employ this language. On such occasions we seldom recollect that nothing is perceived by the eye but a multitude of black strokes drawn on white paper, and that it is our own acquired habits which communicate to these strokes the whole of that significance whereby they are distinguished from the unmeaning scrawls of an infant." What we have to realise is that what is true of a book or other production of our own activity is similarly true also of Nature herself. 12 THE AFFIRMATIVE JUDGMENT tested sometimes by finding what is wanting when the organ of sensation is absent. Thus the blind have no idea of colour but have of form ; the deaf have no idea of sound yet have of musical form ; and so on. In this way it will be found that the donation of sense is altogether meaningless without the datum of thought. But this test alone does not afford a complete distinction between Thought and Sense. We must trace the intellective datum to its source. The idea of form, for example, possessed by the blind is evidently supplied by their activity — not evolved by thought from some inner conscious- ness. And this suggests what we shall find to be the true basis of all cognition, from the simplest perception to the most perfect Science. Science is said to be an expression of the laws of Nature. But i^hat are laws ? They are principles or forms of action. A law describes or prescribes a process, a course of action. If Nature were a mere stationary object it would be subject to no law. Law is universal and abstract, and is constantly distinguished from the sensible, the particular, the concrete. And herein lies the true secret of its universality. The law expresses the form of action irrespective of the where and when. Time and place merely mark the occasions of its interruption. They are the determinants of the actua^. Do not let the meaning of this statement be, mis- understood. No doubt the effect of a natural law varies with particular circumstances. The height of the tides is different when the moon is new and THE AFFIRMATIVE JUDGMENT 13 when she is full. Indeed, periodicity is a character of natural law, but the uniformity of the law is not thereby interfered with. The form of the law is independent of the fleeting state of sensation in which we discover it, and which we endeavour to rationalise in reference to our own life by spatial and temporal references. Now, it is the action and not the sensation which is the object of knowledge. In its essential texture and constitution all my experience is an expression of the forms of action. Apart from action, there would be no such thing as form. These forms are not personal to me. They are common to all ; and the most general of these forms constitute the features of spatial extensity — the subject-matter of geometry. Extensity is usually regarded as the most funda- mental feature of the object world ; but extensity involves a visual element. To the blind, time ordinarily serves instead of space. When my intelligence is related to the world of pure touch alone, I estimate the magnitude of the resistance which sense discovers by direct reference to the duration of the exertions in which they are dis- covered. The periodicity of the animal functions, such as breathing, sleeping, etc., gives a primary standard for such temporal measurement. Vision, by presenting the main features, or at least the visual symbols of the main features, of my environ- ment simultaneously enables me to compare and relate them contemporaneously. And it is the same with all the elements of my 14 THE AFFIRMATIVE JUDGMENT knowledge of the world around. It is not by merely experiencing or feeling sensations that I thus know and reason about phenomena ; it is by associating phenomena together, and by referring them to the action of supposed potent agents or causes. It is thus that we erect the fabric of knowledge. It is in this that cognition consists. In the mental intellective act of affirmation I represent not sensa- tion but the potent kinesis by which the sensible is determined. Ill THE NECESSARY POSTULATE The Affirmative Judgment is involuntary and inevitable. If it be possible in words to doubt the reality of the potent authors of sensible change, it is at least certain that we do not and we cannot for a moment act upon the truth of such a view. Not only do we all constantly, involuntarily, and habitually affirm the existence of active and causative reality, of something real and permanent amidst the things of sense, but we cannot by any effort divest ourselves of the habit of such affirmation. Even Hume, indeed, admitted that he could not. The force of custom, by which he sought to explain it, was, he confessed, too strong for him. Bishop Berkeley invoked the immediate action of God as the perpetual supporter of the phenomenal world . Kant held that such affirmations were the necessary result of the constitution of the cognitive faculty itseK. With modern agnostics Hume's explanation still holds the field. Yet it has been often shown that such explanation is inadequate. Custom, indeed, might no doubt lead us to expect the recurrence of 16 THE NECESSARY POSTULATE certain sensations in a certain order, and if such expectation expressed the whole of our belief and affirmation, such a solution might be sufficient. But our belief includes far more than this ; nay, it is radically different from any mere expectation of this sort. Not only do I believe that when I make the necessary movements and look in the necessary direction I will again see the sun shining, the river running, and the tree standing where it stood. I believe further that these appearances are due to, are caused by, and are significant of the agency and operation of some potent reality which exists and persists altogether independently of my con- sciousness or sensibility. In attributing the origin of these beliefs to our own custom or habit, we are necessarily contradicting the most deep seated and permanent of these beliefs themselves. NeutraUty or agnosticism is no proper name for such a view. All agree that these affirmations or inferences are inevitable, that our every act assumes their truth. And a philosophy which obliges us to deny that proposition or to affirm that such necessity is fictitious is not a position of mere neutraUty. Indeed a belief in the independent reality of the potent causes of sensible change seems to be in- volved in the very recognition of the fact that the sensible world is mutation. Change implies that which changes. If the sensible consists in trans- mutation, there must be something which is trans- muted. The objects of this affirmation are the ingredients THE NECESSARY POSTULATE 17 of knowledge. Without them knowledge would be impossible; speech and language would have no meaning. Not only all science but common knowledge is found on examination to be a conception of things causally related — an explanation of sensible appear- ance in terms of power. The familiar reference to the faculty of perception as the source of our notion of outness or otherness is really found upon analysis to be a reference to potency. The things whose reality we thus postulate and affirm are conceived as the potent and permanent sustainers of the sensible world. We frequently and, indeed, perhaps inevitably conceive them as them- selves qualified by those sensible features which characterise the presentation of sense. But such sensible qualities are but the effect upon our con- sciousness of the operation of the power which sustains the transmutation in which they consist. The real postulate is fundamentally Power. Obvi- ously, therefore, there is no philosophic warrant for the belief that the sensation resembles that which causes it, or that the thing which changes can be truly conceived in the likeness of the change. " For as all works do show forth the power and skill of the workman and not his image, so is it of the works of God, which do show the omnipotency and wisdom of the Maker, but not His image " (Bacon, Advance- ment of Learning, bk. ii.). Many there are who, recognising this, still seek an intellective explanation of necessity and univer- 18 THE NECESSARY POSTULATE sality. " All that you tell us," they say, " may be granted, yet the fact remains that the things affirmed are the creatures of the affirming mind, that beyond its limits any real substratum is un- knowable, that we admittedly cannot transcend the datum of our own experience. It follows, therefore, that the only possible explanation of the belief in reality is subjective: either the mind in some way cognises sensible objects under certain forms or categories, and invests, therefore, the whole of our sensible experience with the forms by which its apprehension is necessarily conditioned and determined ; or else Reality is but a name for that in the environment which responds to the needs of the individual." Such explanations in one form or another have been popular in recent years. Cau- tiously, as they think, abandoning the apparently futile effort to discover the real which underlies the sensible, prudently heedful of the warning afforded by the many failures of the past, and yet unable to rest satisfied with a purely negative scepticism, these thinkers, with a dangerous affectation of wise restraint, seek an explanation derived from the form of the cognitive apparatus, or the requirements of the appetitive impulse, and seem remarkably well pleased with themselves for doing so. But these, no less than other and more candid forms of agnosticism, involve a contradiction, not an explanation of the affirmative judgment. They mean, if they mean anything, that that affirmative judgment is an error. There may be a cause of it or an explanation of it THE NECESSARY POSTULATE 19 and that cause or explanation may have been dis- covered by these investigators. But if so, and if the cause and explanation are what they allege, then at least it follows that the affirmative judgment which we, nevertheless, and which they, nevertheless, persistently and constantly maintain affirms what is not really true. What we require, however, is not a futile attempt, however ingenious, to explain away the inevitable, but a rational account, not only of its genesis and its meaning, but of its inevitability too. IV ACTIVITY Sensation, then, is mutation ; the sensible world is a process ; the changes which occur in sensible and tangible objects are what we call motions ; and the potent causes or operative agencies which we believe to sustain the sensible are conceived and postulated by the mind. But we require to be informed how the mind attains to a consciousness of the Potent and the Real. Now, in all the various phenomena of motion we recognise a fundamental distinction between putting in motion and being moved. Experience does not consist solely of sensation. Amidst my sensible experience I act, I move, I put objects in motion. In and by my actions I contribute to, partake in, and mingle with that kinetic process in which the sensible world seems to consist. My activity is incessant and continuous from the very beginning of conscious life, and contributes largely to the motions of the sensible environment. In considering the fact of movement we must keep in view the necessary implications of the idea. Movement implies that which (using the word without reference to causation) moves. The neces- ACTIVITY 21 sities of thought, perhaps, require nothing more, but my actual experience discovers in movement the cardinal distinction everywhere valid between that which moves or puts in motion and that which is moved — in short, the grand distinction between the active and the passive.^ The origin of this cardinal distinction is to be found in my own motor activity. My earliest consciousness recognises a constant connection between my action and the resulting changes in the sensible presentation. The idea of volition is a later product of abstraction. But my constant motor activity is one of the earliest data of con- sciousness ; and the constant connection which that activity maintains with the surrounding world of sense is the first and most continuously operative element in my experience. The results of that activity may be sensations or sensible changes ; its accompaniments may be the same ; but action itself is not sensation and in no way resembles it. From the fact of thought Descartes inferred the reality of the thinker : Cogito, ergo 1 It may at first seem strange that language should not more aoouiately record the fundamental distinction between moving and putting in motion. I say I move — ^I move the chair. The ball moves or is moving. But language is really accurate. When I say I move, I mean I put my body in motion ; when I say I move the chair, I mean I put the chair in motion ; when I say the ball moves, I unconsciously record the recognition of . the fact that Hnetio energy has been imparted to the ball, in virtue of which it really moves itself as much as I do my body. When, as in the case of the chair, the object has probably no Idnetlo energy, the appropriate and usual expression is, " The chair is moved." 22 ACTIVITY sum ; but far earlier comes the inevitable in- ference from action to actor : ago, ergo possum. It is thence that I derive my idea of Power. My activity involves Effort.^ I am surrounded, not merely by a sensible presentation but by an en- vironing opponent, and the constantly opposing powers by which I am encompassed provide a standard for the measurement of my efforts. My power or capacity for effecting sensible change is in terms of its results a measurable and quantifiable thing. Its existence is not a datum of sense. It is a postulate, an immediate inference which I am compelled to draw from the observed facts of my experience — ^in other words, from the sensible changes which I can and do effect. Such an infer- ence I habitually and incessantly make, and in my ACTIVITY THERE IS THUS SUGGESTED TO MB A SOTJRCB OP PHENOMENA FROM BEYOND THESE PHENOMENA THEMSELVES. Out of this original inference there grows up my belief in the solidity of matter ; that is at bottom a recognition of the inertia or power of resist- ance which the environment offers to my exertional activity. Or, again, if indestructibility be regarded as the essential feature, that means no more than indestructibility by any effort of my activity. My power, in virtue of which I can effect changes in the phenomenal world, is a quantifiable and so far measurable thing, consumed by use and replenished by rest and food; but when so consumed, not thereby destroyed but still represented by its results, Measurability is required to enable us ' See note on p. 85. ACTIVITY 23 to affirm indestructibility, and the knowledge of indestructibility is, therefore, conversely limited by measurability. Every one ordinarily and involuntarily believes in real existence, and distinguishes between the real or self -existent and the unreal or merely apparent. We believe that the world is sustained by something which exists independently of our feeling or per- ception. But such a conviction could never arise from a mere passive condition of receptivity to sensation. The mere passage of a sensible presenta- tion over a purely inert consciousness could never suggest the ideas of action or power. If the totality of experience consisted in a mere stream of such sensible presentations, causation would never have been suggested to the mind. There would have been no need to seek, no thought of seeking, for a real cause of phenomena. There would, indeed, have been nothing to suggest either the existence or the possibility of the existence of anything other than the passive presentation itself. Such a suggestion is derived from the fact of my potent activity, and from that alone. My activity presupposes my organism, and consists in the production of motions therein and thereof. Hence the primary and unassailable conviction I feel in the so-called reality of Matter. It is vain to question the existence of that conviction. It is, however, quite another matter to analyse and explain it. That is what it greatly needs and what it is our object to attempt. 24 ACTIVITY My activity then originates as an automatic and reflex organic function, and even in its earliest stage it determines the form of my experience. By it I am involved in the stresses which result from my action amidst the limiting environment, and thus on the analogy of the results of my own activity I involuntarily postulate other similar powers — the authors of all the other changes which occur within the world of sense. Experience, then, is something very different from a mere succession of sensible impressions. Its fundamental constituent is my own exertional activity. This activity determines the elementary and essential forms of my experience, and the various panorama of sensation with which it is filled arises in the obstructions and interruptions which my activity encounters. It is thence that the affirmative process of Thought is supplied with the elements, by the aid of which it builds up our conception of the world in which we live. How then does Thought apprehend and become the conscious possessor of these facts of our activity? Is Activity a primary cognition, an intuition ? Descartes held the fact of Thought to be an im- mediate cognition from which by inference the notion of the cogitant ego was derived. The fact of exertion is as immediately given in experience and is even temporally prior to that of thought ; and the potent Ego is the corresponding inference. But how does the process of Discourse take up and ACTIVITY 26 cognise the concurrent process of Exertion? It seems strangely difficult to determine how I come to know the fundamental fact of my own activity. Is it an immediate datum, or is it an inference from the sensible experiences of motional change ? Do I perceive immediately that virtue has gone out of me, or is the knowledge derived from the results ? To some extent the answer depends merely on the meaning of the words inference and intuition. In its essential nature the process of discourse, like that of exertion, is a development of potency into actuality. Even intuition, therefore, must be the apprehension or affirmation of one evolutionary process by another. But such apprehension may be immediate,not inferential. It would seem, indeed, that there must be intuition of activity, for the simple reason that there is nothing more immediate from which the idea can be derived. But such intuition, even if theoretically possible, would in itself be altogether wanting in form and definition. It is by the obstructions which the expression of our noematical activity encounters — by the sounds, in short, which are the sensible results of such obstruction — that form, feature, and definition are supplied to the activity of Discourse. In a word, apart from Language, the process of Discourse would be incognisant of its own operation. And in like manner it is by and in the obstructions of my exertional activity that its forms are defined. Sensation seems to be the medium by which both Discourse and Exertion are rendered knowable. 26 ACTIVITY There is no doubt that my actions are commonly and most readily presented to consciousness by their results. These results are neither more nor less than motional changes amidst the resistant objects of Sense. Putting objects in motion or altering their state of motion or apparent rest are the sole or chief results of my actions. I am very apt, therefore, to regard my activity as merely an element in the phenomenal world which we have already found to be a mere process of change. The contribution of my activity to the fabric of knowledge has, therefore, been very much over- looked, if not ignored, by the builders of theories and the framers of systems. But it is never for a moment overlooked or underestimated by those unconscious philosophers whom we call Under- standing, Reason, and Language. The affirmative judgment of the waking consciousness is the per- petual assertion of the potent activity by which the sensible is sustained. It is, then, by inference from the facts of action and its obstructions that I gradually develop the ideas of self and other potent agents, causes, or things. The process of recognition is gradual and instinctive. The activity of my own potent organism and the activity of my enviroimient are from the first intermingled, and it is in the conflict that the idea of myself as an actor is evolved. My belief in potent agents or actors as the authors of the sensible experience which environs me is, theji, of the nature of an inference from the data ACTIVITY 27 of sensible change. To this extent the affirmative judgment is derivative. Of course the knowledge of my own agency seems more immediate than that of any other. It is on the analogy of such activity that I learn to postulate and infer the agency and operation of other real and potent agents sustaining and causative of the sensible world. Both, however, are interrelated inferences from the fact of activity and its obstructions. But if the existence of real agents is an inference it is logically questionable. It may in words be doubted. It requires a mental act which, theoret- ically at any rate, I may decline to perform. If such declinature were really possible, we might in the end be obliged to conclude that the inference is erroneous — that beyond the sensible presentation there is nothing else ; that, as Hume supposed, and as some modern agnostics have maintained, the panorama of sensible change is the only indubit- able fact. We cannot really act on such a view of Experience. But whilst, in fact, the reality of the Potent is unquestionable, in the domain of specula- tion such doubts have been the burden of meta- physical discussion since the days of Heracleitus. After more than two thousand years of philo- sophical inquiry, we still to-day find thinkers who profess them, who will say that at the best the inference is the result of custom and has no certain warrant of truth. Indeed, a very fashionable form of Eclecticism has recently been that which proposes to accept the reality of the given — of experience as 28 ACTIVITY it is. Such a position means nothing and settles nothing. We all start and must start with experi- ence, and must accept its actuality. But this does not necessarily explain to us its reality. And it is just that further interpretation of experience, undertaken with a view to distinguish the real amidst the actual, which constitutes the task of Metaphysics. The question of how the affirmative judgment arises, what is its warrant and its real meaning, has been the primary qusesitum of human specula- tion. It is the problem of the nature of Knowledge. We have sketched in outline the answer which we suggest for its solution. We shall now briefly review the history of the inquiry in order to see somewhat more clearly how such an answer should help to solve the difficulties and remove the continuous contradictions which have perplexed speculation. We shall then shortly indicate the support which such an answer receives from the conclusions of Physical Science and the light which, in return, it is calculated to shed on various departments of Intellectual Inquiry. THE ORIGINS OF METAPHYSIC It was in the discovery of the distinction between thought and sense, between the noumenal and the phenomenal elements in experience, that the prob- lem of knowledge arose. It is in the due apprecia- tion of this distinction that its solution will be accomplished. To the Greeks we owe the grand discovery. Other thinkers may have discussed other important problems. This we owe to them. The Eleatics first became conscious of the dis- tinction expressed in the terms — (pumybiVK, vo^fJi/UToc, Parmenides is credited with the doctrine that reality is unitary and metaphysical, and he is usually regarded as presenting a view directly con- trary to that of Heracleitus, — that all is mutation. But, indeed, they should rather be regarded as complementary. The mutability of the actual, of the sensible, is at least not inconsistent with the unity and immutability of the real, and might almost seem to imply it. The unity and eternity 30 THE ORIGINS OF METAPHYSIC of the K6ff[jjOS is, indeed, affirmed by Heraoleitus, who also in some passages expressly limits the affirmation of mutability to the things of sense. Notwithstanding the subtlety of these thinkers, a marked advance must be attributed to Socrates. He it was who awakened in man the idea of science — of knowledge properly so called — and for the first time clearly contrasted it with sensation. Hitherto speculation had been engrossed with the question of what was the nature of the world and what were the elements of which it was com- posed. Socrates gave a new meaning and direction to the inquiry by reminding man that the problem primarily concerned his own faculty of apprehension. What did he really mean ? We all understand and recognise, and no doubt many Greeks before Socrates had recognised, the fact that we think ; that we meditate upon things ; that we consider about things ; that speech is an expression of such thought, and that thought is very different from what we call feeling. So long as we regard the process of thought as a separate and independent mental activity detached from our perception of the sensible world which surrounds us, this is quite obvious. No doubt Socrates recognised this contrast. But merely to do that would not have been of first importance. There was no new — at least no influential — discovery there. What Socrates did was something other than this. He referred not to the knowledge, if any, which we acquire in virtue of the detached and, so to say, in- THE ORIGINS OF METAPHYSIC 31 dependent activity of thought, but to the knowledge which derives its constituents from the world of our external experience. We may admit, perhaps, that he rather overlooked the distinction between the affirmations which are not founded on exertional activity and those which are. Truth, virtue, red- ness, hardness he seemed to group together in- discriminately as ideas. But at any rate he affirmed that all knowledge properly so called is an intellec- tive process, not a product of feeling or sensation. The ordinary person thinks that knowledge, at least of the external world — and that is the fundamental part of knowledge — is the donation of sense, Socrates affirmed the epoch-making, and seldom appreciated proposition that it is no such thing ; that, on the contrary, it is the structure of thought, of intellective activity. All might agree that cognitions which express the mind's own operations are intellective. The doctrine of Socrates affirms that the science of the outer world of sense is intellective also. In order, therefore, to attain to a true understanding of what the world is, we must first investigate the nature of our own faculty of cognition. When we speak of a straight line, a circle, or an angle, the idea so expressed is quite different from the feeling or sensation involved in the visual presentation associated with these names. Any one of those visual impressions is simply a condition of consciousness, in which or from which we can find or extract a single instance or example of the 32 THE ORIGINS OP METAPHYSIC common notion or idea which we name straight line, circle, angle. The idea is very different from its sensible instance. The distinction is sometimes ex- pressed as that between the form and the matter ; but even that statement does not convey its full significance. At least, if by the form of a thing is meant merely its outline in visual extensity, the doctrine of Socrates is very imperfectly repre- sented by such a statement. The concept or idea of a thing with him included its whole essential nature ; its qualities ; all of it that was cognis- able. In fact, it was of qualities only that Ideas were possible. Nor was this view of knowledge limited to geometrical figures. Our cognitions of such figures admit of an ideal perfection which is not attainable in our cognitions of sensible qualities generally. The form of a geometrical figure seems certainly to constitute its essence. In the case of such figures the doctrine of Socrates appears, there- fore, not only readily intelligible but, perhaps for that very reason, readily credible. But the principle as enunciated by Socrates was not so limited. It applied to Knowledge of all sorts — of all the various objects which constitute our external environment, not less than of the moral qualities and metaphysical notions which are the furniture of reflective thought. Knowledge in every case and always consisted of general concepts or ideas, and was concerned wholly with these. Sensation per se was altogether excluded as a con- stituent of cognition. THE ORIGINS OF METAPHYSIC 33 The doctrines of Socrates being gathered entirely from the writings of his disciples, it has always been difficult to determine exactly what and how much was the proper theory of the master, and what and how much was the supplement of the disciple. The form in which the Platonic dialogues convey their teaching, and the doubt which prevails as to the chronological order of their composition, greatly increase the difficulty of such a determination. But it is perhaps of httle moment. The fundamental distinction between Thought and Feeling, between the intelligible and the sensible, between the law and the fact, between the noumenal and the phenomenal, was clearly laid by Socrates, and has ever since remained the real basis of Metaphysics. Undoubtedly the doctrine was imperfect and inconclusive. That knowledge cannot consist in sensation has indeed been readily accepted by most of those who have reflected on the problem at all. For not only is sensation fluent and unstable, but it seems to contain or be supported by no sort of guarantee or assurance of any identity common to two or more intelligences. Our measurements of sensibles always require and involve comparison with an intermediate standard. To take the very simplest sensation, I cannot tell if blue is blue to another. How can I tell if the sensation is the same to both of us ? The consideration of this simple question at once suggests that when I refer to the mere sensation 3 34 THE ORIGINS OP METAPHYSIO the question is really meaningless. I see at once that it cannot be answered. At the same time it suggests that the subject of discourse is something else than the sensation, namely, the quality or idea of blue — which somehow or other can become the common property of more than one Intelligence. But Socrates did not tell us by what gateway other than sensation these common qualities of the Real world make their entrance into the individual mind, nor how the community of Knowledge is established amongst men. It is the sensible world with which, at least in the main, our concepts or ideas are concerned. How, then, can we attain to an adequate or accurate know- ledge of that world by a process of thought from which the sensible is entirely excluded ? How can Knowledge represent to us a system of things the most conspicuous element of which is entirely excluded from its apprehension ? What sort of thing can this system of cognition be ? What exactly are those cognisable elements of the sensible world which the faculty of Knowledge extracts from the texture of the presentation, and which are said to constitute and to be known to constitute the essential elements of Experience ? These and such as these, reappearing in a thousand forms, are the difficulties with which the theory of Human Knowledge has been constantly confronted ever since its foundation was laid so long ago in Athens, and to answer which has been the main task of speculation ever since. VI REALISM In the hands of Socrates the theory of Cognition, although it proclaimed to mankind a new principle of the very first importance both in its nature and in its results, was still imperfect. He appears to have confined himself to the investigation of the cognitive faculty. " Know thyself " was his con- stant and all-sufficing maxim. It remained to be seen how the faculty of knowledge as he had described and defined it was able to apprehend and represent to itself the multifarious facts and laws of the environing world. One might admit the Socratic view of the noematical or ideal character of knowledge, and still fail to see how we could tell that it had its counterpart in Nature. It was open to his disciples to affirm that the fabric of knowledge is a product of our mental activity, and yet feel obliged still to hold that Cognition of the external as a representative process must be regarded as reproducing — systematically it may be, still also mimetically or pictorially the sensible features of experience as discovered in perception. 86 36 REALISM It might be maintained, in short, that the formal element in knowledge was merely a systematic apprehension of the relations of sensible phenomena. By perception is meant the faculty by which our sensations are apprehended as presented in an orderly arrangement external to ourselves and definitely related to one another and to the things with which we associate them. That knowledge represents this arrangement might be granted, and still it might be maintained that it must also include and, indeed, must he based on a mimetic representa- tion of sensations if it is effectively to express our whole actual experience Of the external world. There was thus an obvious difficulty in the way of the Socratic theory of Knowledge. If knowledge is representative of sensible experience, it would seem that it must itself be, or at least must include, a reproduction of sensible data, — that it must not, or at least must not exclusively, be an intellective system. If so, we are back where we were before Socrates spoke. This difficulty evidently weighed profoundly upon the mind of Plato. Socrates had not gone far enough. The independence and ideality of knowledge were still unsecured. Plato, therefore, made a further and supremely momentous advance. He took the step which led him to say that know- ledge is not an independent reproduction of the constituents of the perceptive act. The perceptive act is itself knowledge. The concept is the essence of the precept. In short, he affirmed in the world REALISM 37 of things an ideality correspondent to that which Socrates had shown to be constituent of knowledge. Intellectual notions or ideas, whilst they compose the elements of knowledge, are also, so he affirms, the essential constituents of the real world of Experience. At any rate the real elements of experience are exact counterparts of the ideal constituents of Cognition. Although Plato called the forms of real things Ideas, and although his language often seems to imply that ReaUty is to be identified with the Idea, he did not, in fact, mean to imply that Reality is the creation of Thought. In his anxiety to emphasise the principle of his doctrine he sometimes uses words susceptible of such a misleading inference, but it is clear from his most mature writings that what he really meant and struggled to convey was that the real and essential character of things was their form or Idea (/Ssa), an element homogeneous with that which constituted the essence of Knowledge, sl^os ; — that it was thus that knowledge was able to cognise and to represent truly the essential characters of the real world. Sensation he regarded as a purely subjective state not only fluent and unstable, but as consisting in mutation, not itself a thing possessed of existence at all ; the objective entities constituent of the world being the ideal forms of things which were or could be reproduced or represented in Cognition. According to Plato, then, the whole fabric of ex- perience is in character intellective. The notional 38 REALISM products of our Intellective activity he had desig- nated ideas — lib)]. Ideas with Plato, as with Kant and with all thinkers worthy of the name, are not faint pictures of sensations, — of colours, sounds, and the Mke. Such, in truth, constitute an absolutely insignificant ingredient of our mental furniture. Ideas are the instruments of intellective activity, the forms of the act of cognition. And that being so, Plato boldly maintained not only that real knowledge consists in and is composed solely of Ideas, but that such ideas, or their objective counterparts, constitute also the very essence — the significant qualities — of reality. Schopenhauer has said that Realism may be stated thus : " When we observe that all those actual things of which alone reality can be predicated are temporal and consequently pass away, while the qualities such as red, hard, soft, life, plant, man, horse, which these names signify, continue to exist independently, and consequently are always there, we find that the qualities which these names designate by means of common conceptions are conceived through their indestructible existence, and therefore have reahty, which is consequently to be attributed to the conception and not to the particular being." Plato, in developing his doctrine, went quite as far as is implied in the statement just quoted. The enduring qualities of things were for him essentially ideal and quite to be contrasted with the sensations which accompany and reveal them. Thought and REALISM 39 existence might be distinct, but they were in quality identical, and it was thus that we were able in thought truly to reproduce and represent the character of the real. So far so good. It might seem as if thus at last we had arrived not only at the true nature of knowledge but at the true essentials of Reality, and had made it clear how cognition of the external was accomplished. But Plato still failed to tell us what was to be done with the sensations. These might be, as he truly showed, mutation merely and unreal, yet they were ever with us. If we could not know that they existed we knew that they occurred. However incapable of being the objects of real knowledge, they still seemed to demand that they should be accounted for. This, however, was what Plato failed to do, or at least to express his explanation in a form available to be apprehended by others. He failed to isolate in thought the potent motive Energy of the Real World. He failed to understand that Thought and Thing are both activities . Award- ing by his theory no place to the independent potency of Nature, to the hvvuyijtg which, by its constant transmutation into actuality, determines, nay, constitutes, the world of sense, he was unable to suggest any explanation of how the sensible arose in experience or what relation it truly held to the pure and formal ReaUty. Accordingly he could make no distinction between the abstract Ideas constructed by or representative of our purely mental activity — the products of moral 40 REALISM sentiments and the like, and those abstract ideas which are founded on a perception. By a species of philosophical trans-substantiation he set up a qualitative unity between the ideal and the external, but he failed to show wherein the pure notion differs from a cognition founded on Experience. Every assertion implies the use of a pure idea. The statement, "That is the letter 'A,'" has no meaning unless the idea of that letter is already in the mind, and is thus available to be employed as an instrument of discourse whenever the sensible phenomenon may suggest it. And in like manner, on the other hand, every single feature or quality which constitutes an element, great or small, in our experience, along with its sensible characters, has at the same time its substantial, or as we prefer to say its dynamic, form, in virtue of which it is capable of representation by the ideative activity of Thought — is, in short, in essence or quality con- ceptual, intelligible, ideal. These two aspects of a thing are related or combined like flame and heat. Such dynamic forms are available to be constantly apprehended by thought as the interpreters, the sustainers,* the real constituents of our experience of the world. In such apprehension Plato held that knowledge consists, but he failed to discover its dynamic origin. Ideas, therefore, with Plato were both general and abstract : general, because as the constant furniture of knowledge they are applicable indifferently to REALISM 41 every sensible instance in which they are expressed ; abstract, because they express the pure forms of thought apart from the accompaniment of sensation. It was to ideas thus conceived that he awarded a true participation in the real world. The form of every object, the notion by which we think of it and to which we conceive that it seeks to attain, is with him, ideal ; but, as already mentioned, this principle afforded no ground for any distinction between the most abstract of moral conceptions and the most solid of material things. The doctrine of Plato under the name of Realism for centuries dominated Philosophy, and is often claimed as the parent or precursor of modern Idealism — to use the somewhat misleading name generally adopted by those who, starting from a basis fundamentally the same as his, go on to affirm that Reality is not only in essence identical with knowledge, but, in fact, owes its existence to the affirmation of the Mind. Such theories in identifying knowledge and Reality deny altogether the representative character of knowledge. They do not so' readily admit or appreciate the fact that they at the same time necessarily deny the truth of our inevitable belief in the independent reality of our Experience. But if to be real does not mean to exist independently either of Cognition or of Sensation, and is not con- trasted with mutation as discovered in sense, then it has no meaning. At any rate all such theories are, and have always been, confronted by the 42 REALISM difficulty which confronted Socrates and Plato — the difficulty, namely, that they leave unaccounted for the occurrence of the sensible presentation. If Knowledge is an intellective process, its ideas cannot constitute the particulars of our sensible experience. On the contrary, the distinction between Thought and Sense directly arises upon the formation of the Socratic theory of Knowledge. The relations of the sensible, the forms of the real world, may be apprehended by thought, but how does that account for the veritable appearance of the actuality of sense ? How does the latter connect itself with the real forms ? Does it inhere in them, arise out of them, or overspread them ? How are they related ? Is jbhere any common ground ? Materiality, the hardness and fastness of the real world, have often seemed to afford the wished- for nexus. But then these seem to be reducible to sensible qualities, and all sensible qualities being, as we have seen, mutation, it follows that they cannot lead us up to reality. Whatever their value as unifying concepts, materiality and hard- ness and fastness, therefore, must' be abandoned as mediators between sense and Reality. The sensible must be accounted for. It was here, we repeat, that Platonism failed. It left sensation an undoubted, but also an unexplained and unintelligible, fact. Deprived of all light on this most urgent problem, it was compelled to rest REALISM 43 satisfied with the consolation that the sensible, being unreal, must be regarded as unimportant, and sought comfort in the reflection that it had at any rate attained to knowledge of the truly Real. VII THE POTENTIAL AND THE ACTUAL StrcH seems to have been the position of Plato. It failed to secure the acceptance of his pupil Aristotle. Aristotle accepted the Socratic exposition of the nature of knowledge as a system of general con- cepts, the product of the mind's constructive activity, but he refused to admit that such concepts adequately explained either the actuality of sense or the reality of the world. He preferred the view that thought, being an affirmation, necessarily points to something other than itself, that affirma- tion requires both a subject and a predicate, and that the predicate could not be furnished by the mere fleeting sensation — in itself a transmutation only — but must contain within itself the explanation and the prepotency of every element of experience, of the entire fabric of environing Nature. The key to this he seems to have found in the very fact that the Sensible is mutability. Transmutation implies also that which is transmuted, or which can transmute itself. That in the transmutation a THE POTENTIAL AND THE ACTUAL 46 process which gives rise to sensation and so con- stitutes the actuality of sense must also exist potentially — b lvydy!tst — and thus furnish the real predicate of thought. The universal element in discourse was not, therefore, identical with the act of thought, but was latent somewhere in things themselves — universalia in re. In other words, whenever we speak of any physical thing, event, act, or operation, whenever the material world of our environment is the subject of our thought or speech, there is a simultaneous reference at once to the sensations which accompany them and to the real energetic operations out of which these sensations arise, in which they consist, by which they are sustained, and without which they cannot evolve into actuality. Nature, Aristotle told us, is the vital activity of an ever-moving power — a constant energy for ever evolving new forms in virtue of its own potency. The potential is ceaselessly transmuting itself, and the kinesis in which the sensible consists is the constant result. Men had confused the actual with the real. However unreal the sensible might be it was still actual, and must, therefore, be accounted for, and the explanation Aristotle found in this perpetual evolution of the potential ; a process which it is the work of knowledge -to apprehend, but not to constitute or create. The ideality of the world was to be found in the potential energy by which it was sustained and by which it became intelligible. 46 THE POTENTIAL AND THE ACTUAL But although it was intelligible it was not, therefore, intellective. Nature herself supplied the ideally apprehended forms of which our knowledge seemed to consist. As Leibniz very truly says {Metaph. viii.), " Every true predication has some basis in the nature of things." Intelligence and the In- telligible world, notwithstanding their affinities, are neither identical nor coextensive. On the one hand, the intellectual world is more extensive than the Intelligible world. We possess many general ideas to which no substantial entity corre- sponds. But, on the other hand, it is equally true that the intelligible world is not only distinct from Intelligence, but is part of a much larger Whole. It is a mere fraction of the vast energies of Nature. It is only that fraction which, from its affinity with the Activity of Thought, is capable of representation in Cognition. Even within the organism there are regions of activity below, above, beyond the reach of cognitive apprehension. The sub-liminal self is an ocean in which the cognisable and the cognitive are each but a single island or an isolated current. VIII THE MIDDLE AGES What might have been the consequences to Philo- sophy had Greek thought sustained the speculative inquiry until Aristotle's profound conception had had time to be realised it is difficult to say. But it did not. In the establishment of the grand distinction between thought and feeling, between the noumenal and the phenomenal, between the universal and the particular, between the law and the fact, between the objects of reflection and the objects of sense, Greek thought gave birth to Philosophy. But it died in the effort; and the unnourished infant was left to struggle through the Dark Ages. It is true that, in the then existing state of the knowledge of Nature, Aristotle's theory was in- volved in difficulties almost as great as those which enveloped Realism. If Plato failed to explain how the idea could be potential amidst the things of sense, Aristotle failed, perhaps equally, to show how, if it were excluded from such participation, it could ever become cognitive and affirmative of what was to it a foreign land, or rather an unstable 47 48 THE MIDDLE AGES quicksand. And so throughout these Middle Ages it was Platonism that really held the field. Aristotle, no doubt, was the most studied teacher in the schools, but the Aristotle studied there was the Aristotle of the Logical Organon, of the formal exposition of the laws of thought itself — a subject to which the Platonic ReaMsm had given its chief significance and import. Those treatises in which he had elaborated, in opposition to Plato, his metaphysio of the real world and set up his theory of the potential and the actual in contrast with the pure intellectualism of the Academy, were forbidden or at least unknown. A provincial synod held at Paris in 1209 ordered that the Metaphysics which had recently been brought from Constantinople should be burned, and that no one should read them or keep them in his possession. Six years later a Roman legate dis- patched by Innocent iii ordered that the Dialectic or Organon of Aristotle should be read, but for- bade the perusal of his metaphysical and physical writings. In 1231 a rescript of Gregory ix ordained that his works on Natural Philosophy should not be used till purified of error. In 1265 the regula- tions of Innocent in were confirmed by Clement iv (Barrington, History of the Middle Ages). Thus throughout the Middle Ages men for centuries maintained their endeavour to construct the science of Nature by rational deduction from their own mental conceptions. In the very limited sphere of Logic and Geometry all went well. But when men extended this method to the knowledge THE MIDDLE AGES 49 of natural law, operating beyond the limits of their own mental and motor activity, all was blank failure and disappointment. "For the wit and mind of man, if it work upon matter which is the contemplation of the creatures of God, worketh according to the stuff and is limited thereby, but if it work upon itself as the spider worketh his web, then it is endless, and brings forth indeed cobwebs of learning admirable for the fineness of the thread and work but of no substance or profit" (Bacon, Advancement of Learning, bk. i.). Alchemy and Astrology were examples of the object, the method, and the achievement. Through- out the period of the scholastic discussions Realism, therefore, was supreme. And by Realism was meant the doctrine which more or less completely identified Reality with the conceptions of thought — a doctrine which, as we have seen, has in modern times been reasserted as Idealism. It is generally said that the Scholastic period closed with the re-establishment of the principles of Nominalism, which, as opposed to Realism, affirmed the distinction between thoughts and things, and which, though called Nominalism as opposed to Realism, would in these days be very likely described as Realism in contradistinction to Idealism. At any rate, whilst Realism prevailed, so equally prevailed the doctrine which affirmed at least a qualitative identity between knowledge and reality, and endeavoured to draw from the necessities of thought the essential elements of the object world. 4 IX THE BETtTRN TO NATURE Ip the Idea is in quality identical with the essential elements of Reality, it is not unnatural to suppose that by rational deduction from the implications of Thought we should be able to deduce the laws and characters of the Real. This, therefore, was the method by which for so many centuries the study of Nature was pursued. But the result was barren. It was in the protest against these methods that modern science arose. Convinced at last of the futility of attempting to attain to the knowledge of Nature by deduction from their own conceptions, men resolved with Bacon to return to Nature herself — to seek in the phenomenon, in the actuality of sense, the true if hidden principles of natural law. They had discovered that they could not derive the nature of things from the implications of Reason. They resolved of new to seek the key amidst things themselves. The establishment of the ever-growing system of modern natural science has been the triumphant result. Surely the protest has been 60 THE RETURN TO NATURE 51 vindicated. Evidently there was something wrong in the medieval method. The movement reflected itself upon Metaphysics. The implications of Reason had proved useless as instruments for extending our knowledge of Nature. Had they any value left at all ? At any rate, was it not essential to review the matter from the very foundation ? Descartes inaugurated the new spirit, and resolved to make a complete re-examination of all our mental conceptions and affirmations, and to ascertain afresh which, if any, were absolutely and necessarily true. The reality of the process of Thought was not, indeed, at first denied. Descartes started with a " cogito." It was to the reality of the external world that his method was applied. But the new habit of mind, which had led the physician to accept the actual and the sensible as the first and most immediate datum of natural knowledge, spread like a contagion to Metaphysics, till, with Berkeley and Hume, the presentation of sense obscured and overwhelmed its own ideal framework, and the very fact of thought, the very actuality of the reasoning and cognitive functions, was overlooked or forgotten. Ideas were regarded as merely faint reproductions of the things of sense. The entire content of consciousness was supposed to be supplied ab extra to the mind by sensation. Those thinkers misapprehended fatally in what the new method of Science consisted. Science had turned to Nature, to the external, to the sensible, 52 THE RETURN TO NATURE to the phenomenal. But it was not to mere feeling or sensation that Science addressed her fruitful inquiries; it was to Nature as a potent dynamic operation. It was by acts of experiment, elimin- ating the forms of natural action, and by repre- sentative observation of natural processes, that Science conducted her inquiries and ascertained their laws and forms. In short, Science is through- out a study not of sensation but of Power in action, of which sensations merely indicate the fluctuations. And it is to this fact that we must attribute its effective extension. SENSATIONALISM AND INTBLLBCTITALISM The failure to deduce the Science of Nature from the implications of Thought had thrown men back upon the external and the sensible, and in this position they not only overlooked the fact that it is still thought which apprehends the relations of the phenomenal world, but entirely forgot also that it is only as the signals of the potent kinesis in which Nature consists that sensations possess any meaning. So disappointed were they with the results of the medieval effort that they inclined to deny the reality of intellection altogether, and to repudiate its office not only as constitutive, but even as representative of the dynamic process of reality. Thus it was partly with Locke and wholly with Berkeley and Hume. Reverting with a rush to the sensible as the key to knowledge, they regarded the idea as a mere faint reproduction of sensation, and, disregarding altogether the activity of the affirmative judgment, they looked upon the sensible presentation as a stream flowing over a passively S3 54 SENSATIONALISM AND recipient consciousness. Ideas were but the images by which sensations were reflected in the silent mirror of the mind. They altogether overlooked — probably because they did not understand it — the Aristotehan principle that the sensible was the mutation of a potent, ever kinetic energy, capable of presentation in knowledge because, and only be- cause, both Knowledge and Reality were activities of correspondent character although separate and distinct. Berkeley's ardent spirit seems to have led him to embark upon philosophic inquiry without having first really taken sufficient pains to understand the meaning of the Socratio theory of knowledge. This defect tainted all the efforts of his splendid genius, although in his later writings he seemed to feel himself obliged to restore to Philosophy under the vague name of notion what he had refused to recognise as idea. The result was the development of a school of thought by which experience was reduced to a mere stream of impressions beyond which we could not penetrate — a conclusion which really made knowledge impossible and truth un- attainable. It was a conclusion, moreover, upon which no man could act. That fact alone should have made it at once evident that it did not supply a satisfactory solution of the problem of knowledge or a satisfactory explanation of experience. Hume, indeed, admitted that custom or habit constrained him to affirm realities not given in sense, but he held that the affirmation had no other basis of INTELLECTUALISM 55 validity. Beyond the actuality of the impression he found no reason for affirming the existence of any subjacent reality. The logical consequence of such a position should have been the abandon- ment of the vicious habit. This being impossible, the disciple of Hume is left in a position of hopeless inconsistency, for his theoretical conclusion requires the denial of postulates which he finds it impossible, for a single moment, even to doubt. Of course a position so reactionary involved and invited protests. Reid's disclaimer in the name of common sense, irresistible in its cogent honesty, was, however, a mere reassertion of the affirmative judgment, and offered no solution of the difficulties in which speculation had become involved. But the scepticism of the time led also directly to the more formidable protest of Kant. Kant sought to restore Philosophy by again deriving from the constitution of the cognitive faculty the permanent relations and enduring features of the object world. Avoiding the weak- ness of seeming to project ideas amidst the things of sense — a weakness which might have been charged against Plato — he sought to sustain and co-ordinate the mass of sensible phenomena by an articulated fabric of mentally generated categories. So far as the formal constituents of knowledge were concerned — the principles of enumeration and the laws of space — the truth of Realism had never been shaken. It was when men sought to penetrate 66 SENSATIONALISM AND farther into Nature's secrets that its method had failed and that observation had been found effective. Did Kant really help us ? He formulated a scheme of cognition under which the vaUdity of knowledge was explained in terms of the categories of space and time imposed on the faculty of sensible intuition, and of the cate- gories of the understanding by which were furnished the necessary implications of the reasoning process. The laws of Nature were to be deduced from the observation of phenomena and were supposed to be thus accounted for. The phenomena themselves re- mained as an inexplicable and irreducible residuum. Now, however clearly the laws of Nature may be distinguished from the principles of enumeration and of spatial form by their want of a priori certitude, yet they are not gathered and apprehended by mere passive receptivity. The whole science of Nature is an intellective investigation of causes. As Science advances to perfection it increases also in ideality. But along with such ideality is carried the concurrent affirmation of reality. The laws of Nature are cognised as objectively valid and as forming the inherent and self-existent texture of the real world. Kant's metaphysic involves a surrender of this feature of scientific cognition. Although he recog- nised that knowledge of Reality required and de- manded some objective basis, which he endeavoured to find supplied in intuition, he must still be held to have admitted that knowledge of the INTELLECTUALISM 67 external, properly so called, is unattainable. What is an intuition ? The term seems to be derived from a misleading analogy between Vision and Thought, If, indeed, Vision be conceived as an activity, the error can hardly arise. But Vision being commonly regarded as a passive state, men erroneously conceive the mind in like manner to be the passive recipient of propositions self-evidently true. But all such propositions are really assertions which the mind necessarily makes in virtue of and in obedience to the laws of our organic constitution. They express the forms of the process in which our Activity partakes. Intuition somehow has reference to the apprehension by our noematical activity of the facts and forms of our exertional activity. This, the essential nature of Intuition, was overlooked by Kant. According to his view, apart from what is supplied by the categories, no real knowledge can exist. The mind is really limited by its own forms, which are imposed upon the indefinite datum of sensation and thus con- vert feeling into knowledge. Knowledge, therefore, ex hypothesi, is limited to the self-erected struc- ture of Intelligence filled in by the unknowable phenomenon. Such a view, though less obviously than the scepticism of Hume, is, in fact, quite as completely a denial of cognisable reality and a contradiction of the postulate which the afiirma- tive judgment incessantly predicates. It has inevit- ably led to the evolution of that school of German thought which more and more completely has 58 SENSATIONALISM AND gravitated towards a pure monism, to those theories which hold the reaUty of the external world to be an affirmation of the Mind. More systematic than Plato's, Kant's explanation of our beliefs was essentially a monistic elaboration of the principles taught in the Academy, and not- withstanding the vigour with which the movement 'has been sustained and the assurance of its votaries, it is nevertheless evident that it is now about to exhaust itself without solving the problem of knowledge. If, indeed, knowledge, being intercepted by its own forms, never really reaches reality, how could the result be otherwise ? It is allowed, nay alleged, that the world of knowledge is the creature of that knowledge itself. We cannot, therefore, get out of ourselves. The forms of the cognitive faculty may systematise into science the illiquid datum of feeling, but the real thing in itself can never thus be reached. Nor can such a theory in any way explain how the sensible datum arises and makes its way into consciousness. It is equally evident on mature consideration that the assumption of spatial tridimensionality as a primary datum of knowledge is without logical warrant. In postulating the categories of space and time as original a priori elements of his mental furniture, Kant really borrowed from Nature, and started off on his investigations with a complex datum which he never attempted to explain or to reduce to simpler elements, nor even to account INTELLECTUALISM 59 in any way for its presence in the changing texture of cognition. The futility of idealism is now begun to be realised. All attempts to identify knowledge and reality, to regard reality as in very truth created by an affirmation of the mind, are subject to two great and ultimately fatal objections — (1) they do not account for the presentation of sense which we inevitably regard as, if not real, at least actual, and as the surest guarantee of reality; (2) in robbing Reality of its independence of Cognition they rob it of its all. On the other hand, all attempts to maintain a separation between knowledge and reality, and to regard knowledge as representative, have been vitiated by the supposition that such knowledge must be a mere reproduction of the sensible pre- sentation, and seem, therefore, to involve a denial of the reality of what is known. Neither result is satisfactory. But if, admitting knowledge to be representative, we regard it as an activity, — representative not of sensation but of the dynamic process by which sensation is sustained, and by the transmutation of which the sensible can be explained and accounted for, — it seems that thus at last we may find a solution which avoids both of these objections. Recognising that the organism of man comprises two great Activities, Thought and Exertion, we can find, independently of. Cognition yet still given to us a priori, the necessary forms of Reality. 60 SENSATIONALISM AND In one way or another the inevitable result of the idealist view is to identify the idea with the real, the concept with the conceptually apprehended entities which sustain the fabric of experience. All that can be urged against the realism which dom- inated speculation for two thousand years can be urged with equal force against this more extreme and one-sided extension of the same principle. Amplify it, elaborate it as you like, this central difficulty remains. Schopenhauer felt the difficulty very strongly, and endeavoured to remove it by his doctrine of the Will-to-live as the ultimate reality in experience. But this vague postulate, though in principle true and significant, failed to furnish the necessary nexus by which the potential and the actual must be co-related if a representative theory is to be maintained. What we want is an explanation of how the principle of the Will-to-live evolves and develops the multifarious features of actuality. This cannot be done in terms either of intellectual activity or of any form of volition. The potency which sustains our experience must be conceived as something which participates in and out of which we can intelligibly evolve the sensible world. Philosophy is not a detached and self-continent inquiry. It demands the exercise of the most mature and highly cultivated intellectual effort. But the world with which it deals and which it seeks to explain is still, after all, the same actual, sensible, ever-present world of daily experience in INTELLECTUALISM 61 which we Uve and move and have our being. And unless and until we can definitely relate the postulate of our Philosophy with the infinite actualities of experience we have not arrived at truth. XI THE DEFECT OF EEALISM AND IDEALISM The doctrine of realism, whatever else it may have explained, failed to explain the appearance of the data of sense. The cognitive ideas of Plato, whilst they seem to express the forms, the relations, and all the essentials of reahty, are impotent amongst the things of sense. How do they generate the actual, how originate or sustain the constant trans- mutation in which actuaUty consists ? However unreal the sensible and the phenomenal may be, it is undoubtedly actual. Nay, it is their constant association with the actual and the sensible which fundamentally distinguishes real things from ideals. A reason for this is just what Platonic realism failed to furnish. And the idealist of modern times has done no better. He, too, recognises the sensible as the inexplicable phenomenon organised possibly into a system of knowledge by the innate forms of the cognitive faculty, but remaining still unex- plained both as regards its appearance and its evidently deep and unique relation with reality. Materiality, so far as its forms are concerned, is DEFECT or REALISM AND IDEALISM 63 resolved into a projection of the forms of the cognitive instrument ; so far as regards the most permanent of its sensible qualities — its hardness, solidity, resistance — these, like all the others, are recognised as, ex hypothesi, at the best transitory and unreal. Indeed in its modern Kantian form. Idealism, as it is called, labours under a still more serious difficulty. It finds the origin of the a priori and abiding elements of experience in the constitution of the mind. It locates them in the cognitive faculty itself. But it for long failed to realise what is now, however, pretty widely appreciated, that in so doing it practically denied the possibility of real knowledge. If knowledge in its search for truth is perpetually limited by its own forms, its cognitions, however necessary and imperative, can have no valid and effective reference to the real world. If, for example, space is a primitive in- tuition, we may thus account for the self-evident truth of geometry, but we cannot account for its applicability to the external world — an external world which we can never really know if the forms of things are determined for our cognition by the structure of our own faculties. The rational ex- planation of experience must not require the em- ployment of an unknown and unknowable key. In some way we must find the explanation within our experience. On the other hand, if we are to explain experience we must get beyond the cognitive faculty. Merely to set forth the implications of 64 DEFECT OP REALISM AND IDEALISM our own cognition is of no avail. It leaves us with a purely subjective idealism, a theory which, as we have so often seen, is a mere denial of the undeniable convictions of our daily life. How, otherwise, can these two requirements be satisfied and harmonised except by the postulate of power, furnished by and derived from our own activity, yet discovered in that activity as also the unifying explanation of all the diversities of the object world ? To reach the Real we must transcend not only sensation but cognition. We must get beyond our conscious selves, yet we must not transcend ex- perience. The Real, therefore, can only be found in the other — the non-cognitive — the exertional element of our Life, and that element being also that which interacts with and which participates in our environment, seems obviously the element from or by which we derive the knowledge of the independ- ently real. In our exertional Activity we are linked and intermingled with the dynamic system which constitutes our environment. Community of know- ledge is rendered possible by and only by this participation. When the phenomena of sense can be accounted for as transmutations of a real Energy or potency, then and only then can their appearance be explained by a theory con- sonant with the requirements of an intellectual Metaphysic. XII THE NATURE OF KNOWLEDGE The true theory of human cognition is to be found, therefore, in the proposition that the idea represents action, the sensible impression merely the obstruc- tions which such action encounters. Our ideas are our stock of mental activities, by which we frame the fabric of Knowledge, and which are for that reason generally applicable to its interpretation, and these are not pictures of sensations but ex- pressions of Activities. Just let any one honestly reflect on what he really means when he says, " That is an angle." Does he refer to a piece of visible colour ? Does he not know that the essence, the form, the reality of the angle is Hot in that nor in any sensation at all ; that the sensible accompani- ments are mutable and indifferent ; that what he really and truly means by an angle is the form of an action ? In every sensible experience there is embedded the idea, the intellective apprehension of its dynamic potency, of which the sensation is but the accom- paniment and the fringe. 5 66 THE NATURE OP KNOWLEDGE Leibniz truly says {Metaph., transl. by G. R. Montgomery, xxvi.) : " Our soul has the power of representing to itself any form or nature whenever the occasion comes for thinking about it, and I think that this activity of our soul is, so far as it expresses some nature, form, or essence, properly the idea of the thing. This is in us, and is always in us, whether we are thinking of it or no." We habitually speak of a thing by reference to its sensible accompaniments, but we constantly dis- tinguish them in thought. We see a line of white foam on the water. We say that is the course of the ship. But we mean really by the course of the ship a process of dynamic activity of which the track of foam is but a symbol and accompaniment. Let the reader but reflect, and he will be surprised perhaps to find that this illustration is of universal application. Every furrow in the field is, for Knowledge, the track of the plough ; every line, the shape, the form, the contour of every visible thing is the expression of the potent energetic operation which has produced or is producing it — of the dynamic process which maintains it. It is true that we must ever start from a datum of observation, and with a description apparently static. Such datum is a section taken across the process of Reality. Without such data we should have no points of reference. It is by these we featurise Experience. As we shall see later on, we never give a name to an act until it has eventuated in a fact. That is why Matter seems so real to us. THE NATURE OP KNOWLEDGE 67 Our visible pictures represent not action but the result or supposed result of action. No race- horse's legs ever occupied the positions in which they are visually depicted by the artist. But if we analyse such observational descriptions we find that they are built up of buried dynamics. One who did not know a plough might yet describe a furrow as a triangular cleft in the ground running in a straight line across a field. But have we not found that a triangle and a straight line are the names of acts ? and is not the same true of a cleft and of a field ? The mariner observes his position at noon. It is a static fact, but it is determined by dynamic changes ; and is not its object to determine the course of his vessel ? What is true of the visible is equally true of the tangible, of the audible, and of the whole sensible world. All tactile resistances in some way express dynamic action. Music may excite an indescribable variety of emotions in its auditors. It is only capable of becoming an object of Knowledge when its elements are apprehended in terms of the real dynamic process in which the sounds arise. When the metaphysician tells us we can know only relations, he is vaguely hinting at the truth that the cognisable Reality is a unitary energetic process of transmutation in which all sensation arises and apart from which it is meaning- less. The merest child readily recognises the scantiest outline or skeleton figure as the object to which it refers, provided only it expresses truly the dynamic form, although such outline is altogether 68 THE NATURE OF KNOWLEDGE different from the sensible appearance. How could he do so unless because he unconsciously- recognised its dynamic idea as the essential con- stituent of the thing. Dr. Thomas Reid, in his Inquiry concerning the Human Mind, long ago proved in detail that the elements of Knowledge were not pictorial reproductions of sensations at all. Having thus removed the fallacious theory of their origin adopted by Berkeley and Hume, he accounts for them merely as the irresistible convictions of Common Sense. Had he only reached their true derivation from the facts of Activity and realised that Cognition is a mental activity which repro- duces and expresses the activity of exertion, he would have gone far towards solving the first problem of Knowledge. But both he and Kant failed to locate in our Activity the true foundation of our Knowledge. And so it is that we still constantly encounter the ancient tenets of the phenomenalist and the sensationalist. By all such it is supposed that knowledge is nothing but a collection of the impressions of sense. Even in recent times it has been affirmed that the ideas of things — even of geometrical figures — which we form in the mind are simply copies of the particular instances presented to us in Sense. Such a view, extreme and absurd as we deem it to be, seems to illustrate the impossibility of alto- gether getting away from the truth. For what is a copy ? How is a copy made ? In some way or other it is the result of an active effort. THE NATURE OF KNOWLEDGE 69 Even were we to allow for a moment that ideas were thus derived from sense, it should be evident at least that, once formed in the mind, they are independent of the particularity of sense and apphcable generally to the various instances of actual presentation. Not only so, but they are liberated from the defects of sensation. The circle which the mind thinks of is a perfect circle, and so of the angle and the hne. It may be that we cannot represent a perfect circle to sense ; but that only emphasises the distinction. It may be, it is, equally true that we cannot frame a mental picture or image of a circle without investing it with the particularities and defects of sense. We cannot frame such a mental image of a triangle which is neither equilateral, isosceles, nor scalene. So said Bishop Berkeley with undoubted truth. But the notion of a triangle, as he latterly seemed to have realised and which is what Socrates meant by the idea, is as certainly general. The idea of a triangle enters into the process of discourse without any particularity, indeed apart from any definite conception of any particular species of triangle. Discourse employs and utilises what it requires. The activity of Discourse being freed from the obstructions in which sensation arises, is free also from the limitations which particularise sensible experience. That is the essential nature of the process of thought, although by thinkers like Hume and Berkeley it was ignored. 70 THE NATURE OF KNOWLEDGE And what is true of geometrical conceptions is in this respect true also of the ideas of all other things. We do not in thinking about them frame mental images or pictures. Ideas succeed one an- other in the process of Discourse without any pictorial presentation. We ask any one, Is it true that ordinary discourse involves a constant pictorial panorama of the subjects discussed, many of which are altogether incapable of visual representation at all ? The explanation, then, of this generality of our concepts or ideas is to be found in the fact that they reproduce or represent actions. In consequence of the periodicity of all natural processes and move- ments their activity is constantly repeating itself. Sensations may punctuate and individualise our Experience. The process of Thought, however, is adapted to represent action apart from the particularity of sensation ; hence the generality of conceptual Discourse. The same considerations explain the purity or ideality of Knowledge. For if we consider the world also as an activity, we shall find the pure forms of things everywhere, not only in thought but in Nature. Discourse in its ideality is not thereby less but more truly representative of the dynamic process of Nature. Indeed only thus can it be representative at all. Every planet, unless in so far as it is otherwise acted upon, describes a perfect ellipse ; every bullet, unless otherwise deflected, a perfect parabola. Its flight is a perfect THE NATURE OF KNOWLEDGE 71 compound of several pure and perfect motions. Every stone which falls to the ground expresses in its action the pure forms of the laws of gravity and frictional resistance of which its motion is compounded. All action is pure. It is with sen- sation that imperfection enters. It is quite certain then that Thought, even when engaged in affirmation regarding the sensible exertional world, is an altogether different process from pictorial or phantastical reproduction of sensations. What we express in thought is the character of the thing, its form or essential nature, in short, its dynamic potency. Such form may not be always capable of complete expression as it is in the case of geometry, but that is because our apprehension or knowledge of the characters of the thing, or our power of representing them, is in such cases imperfect. These characters express the potency of the thing — that is to say, what can construct it and what it, being constructed, can do. If the construction of the thing is within my own potency, the conception of it is complete. If not, it is incomplete. It is because geometrical figures are the fundamental forms of our ovm organic activity that we can attain in their case to per- fection in our ideas and reasoning. A machine is only partially within ouV potency, because the materials are furnished ah extra. Postulating perfection in these, you can conceive it as perfectly as you can a geometrical figure, the construction of which is wholly within your own power. And 72 THE NATURE OF KNOWLEDGE although in the department of natural knowledge we may not be able from the implications of the idea to develop completely the phenomena which it manifests in actuality — as, for example, from the idea of a rose we may not be able to deduce all its properties as we can from its idea those of the triangle — that is rather due to the necessary im- perfection of the induction from which we derive the idea than to any logical impossibility of such a deduction. In every case of an idea which re- presents our own constructions this difficulty disappears. And it is at least evident that in the case of the rose or of any other sensible object whatever, no less than in the case of a pure geo- metrical figure, its essential elements are noematical. Its very smell, although smell is perhaps the least intellectual and most purely sensuous of sense impressions, is simply a particular form of physical action ; the expression of a particular potency in the thing, which may variously affect different subjects and which in its essence is apprehended as Idea. We cannot hnow the smell except by reference to its action — how it affects ourselves and others. We may feel it, but we cannot say if our feeling is the same as that of any other person. Knowledge as a common possession and the subject of Discourse must be supported entirely by a reference to the dynamic significance of the thing. The potency which our Activity discovers as the common medium of existence is the only basis of Knowledge. Whenever we proceed to cognise, to THE NATURE OF KNOWLEDGE 73 think about anything, even about a sensation as subjective as smell, we are considering the action in which it consists. We speak of rivers, mountains, men, houses, trees, in short, of all the objects of discourse, without usually framing any particular picture or any picture at all of their visual features. The blind who could never do so are as able to engage in rational discourse as the vident. Are all such unvisualised and unimaged ideas confused and meaningless ? Not so. On the contrary, con- fusion and unintelligibility would be the first result of any attempt so to represent them. Sensa- tion is obscure and meaningless unless and until idealised and thus rationalised. Visual sensation owes its pre-eminent value not to its " colour scheme " but to its capacity for such interpretation. Our sensations are made clear and definite when interpreted in terms of power in action. We think of the river or of the mountain as it stands related to our exertional activity, or, with a fuller and more scientific apprehension, as the expression of its own dynamic significance. Ordinary knowledge conceives of all such objects in their relation to the subject's own activity. Science proper conceives them in terms of their dynamic significance in the system of Nature. In both cases their dynamic significance constitutes their idea. The intellectuality of those affirmations which express the sentiments of the mind is, of course, still more obvious. Take the case of abstract ideas, 74 THE NATURE OF KNOWLEDGE such as the ideas of virtue, truth, honesty, etc. These clearly cannot have a sensible origin. Yet they form a very important element in intelligible discourse. We must find a view of rational dis- course compatible with the use of such ideas as these. Indeed all abstract ideas are incapable of sensible representation, yet they form the in- dispensable furniture of thought. We must find some explanation of how, with such ideas as these, Discourse is possible. And the explanation is only to be found in the fact that all alike express the characters of action, and that our intellective power is adapted directly to express such characters. The Real, then, is an active energetic kinesis. Sensibles are but the interruptions or turning-points in the constant process of experience. By these our attention is arrested. Perception is awakened by sensation. Every sensation arises in obstructed action. It is by and in virtue of our sensations that we identify our experiences. But it is in virtue of the potency which sustains the process and of the laws of its Activity that objects acquire their various characters and forms — characters and forms which are doubtless discovered in the sensa- tion but which belong to the process itself, not to its interruption. XIII CAUSATION It is perhaps the consciousness of the difficulties which seem to beset all theories of knowledge which has led latter-day Idealists to deny the fact of Causality altogether. For that is truly what they do when they reduce causation to a mental affirma- tion suggested by invariable sequence. Here, strangely enough, they make common cause or occupy common ground with their op- ponents, the Phenomenalists. It was these latter who first suggested this method of disposing of the idea of causation. As Schopenhauer well points out, the question of the meaning of causation hardly arose in ancient times. It was Hume who first questioned the validity of such a postulate, and demanded its credentials. He perceived clearly enough that if the sensible presentation fiowing in a constant stream over a purely passive consciousness constituted the entire groundwork of experience, there was no warrant for the postulate of cause ; and he therefore found an explanation for it in his favourite appeal to custom and habit engendered by invariability of sequence. 76 CAUSATION If the verity of the postulate had been accepted without question up till Hume's time, the validity of his explanation has been accepted since with an almost equally childlike faith and confidence. Even Kant, though he supposed that the notion of causation was imposed upon the presentation by the categories of causality and dependence, and that it thus derived its character of universality, did not attempt to dissociate, or, at least, did not succeed in dissociating, it from the idea of invari- ability of sequence. The same principle is some- times expressed in the statement that causality is a nexus mentally established in virtue of repeated coexistences of similar recurrent phenomena. And since Kant's day even a thinker so orginal and un- conventional as Schopenhauer has explained causa- tion in terms which are almost repeated by the latest of the Neo-Hegelians. And, indeed, this strange agreement between schools so diverse is not so inexplicable as it might at first appear. We have seen that the defect of realism is the impotence of ideas £|,midst the things of sense. It may be said that the defect of phenom- enalism is the impotency of sensation amidst the things of thought — the things, that is, which thought obliges us so constantly to postulate and affirm. But in either case it is vain for the supporters of such a doctrine to pretend that they thereby explain the mental postulate of causality. At best they explain it away. If invariability of sequence CAUSATION 77 is the true explanation of the postulate, then the affirmative judgment is constantly wrong, and the fundamental conception which lies at the root of our belief in the reality of the world around is based upon a constant error. And the failure in both cases is traceable to the same source. Both Idealists and Sensationalists have overlooked the significance of our dynamic activity amidst the things of sense. A few very acute thinkers have from time to time pointed this out. As these men have maintained, it is in our sense of effort, in the experience of our dynamic activity, that we must find the origin of the postulate. The explanation of causation by reference to invariable sequence is based upon an essential misconception of what causation means. In point of fact we never regard one phenomenon as a cause of another ; and regularity of sequence, so far from being the true test of causation, is the very opposite. It is when the usual sequence is inter- rupted that we look for a cause, and when such interruption becomes periodic and regular it gradu- ally seems to lose its causal significance. In many of the most invariable sequences, such as that of day and night, no causal nexus is ever suggested to the mind. Indeed, this example is a good instance of the truth that invariability tends to obliterate any suggestion of a causal nexus. Causation is invariably a reference to potency. In every case in which I refer to a cause, I refer 78 CAUSATION to the potent energy in virtue whereof the trans- mutation in which the phenomenon consists is de- veloped into actuality. And this enables us at once to explain the difficulty so frequently stated and with so much satisfaction — the difficulty, namely, of eliminating the cause amidst the antecedent phenomena. " What," asks a recent writer, " is the cause of the fire burning in my fireplace ? Is it the coals that were placed in the grate, the sticks and paper which were laid below, the match which lighted them, the housemaid who struck the match, the man who made the match, the miner who dug the coal, and so on in an indefinite regress ? " Now in every case and always our sensible world at any given point of time is a datum of configura- tion — a term which has its strict dynamical mean- ing. In stating any dynamical problem we must start with a postulated datum of configuration. That datum, as we know, has a given potential energy, and the cause of any change in that con- figuration is the energetic transmutation in which such change consists. Given as the datum of con- figuration the made-up fire, the sticks, the coal, and the box of matches beside it, then the housemaid's action is the energetic transmutation which is the cause of its alteration. Extend your range of cognition. Take as your datum the empty grate. The cause of the first change is the activity which introduces the coal. And so on ; the causes are as numerous as the changes which they originate. CAUSATION 79 but what we mean by the cause in any particular case is always the activity which involves the change upon the datum last postulated. And if you take the universe as a whole, the totality of the energetic transmutation is the cause, and the totality of the phenomenal resultant is the effect. It is therefore clear that it is on the analogy of my own active experience that I postulate causation. Were I a mere sensitive plate receptive of sensa- tions, the idea of causation could never arise in my mind. There would be nothing to suggest the power which underlies the sensible. It is in terms of the powers which sustain my own activity that I conceive the dynamic system. That system is discovered in virtue of the opposition which my own power encounters. And this necessarily im- plies the hxjmogeneity of the opponent. There cannot be opposition between entirely disparate agents. The mere fact that they resist one another implies a certain community. There have been nations which could not go to war because the force of the one consisted of an army of infantry, and that of the other of a fleet of ships. A battle implies a battlefield. Strange as it may sound, opponents cannot oppose unless they meet upon some common ground.^ Thus it is that on the analogy of my own activity I postulate potent efficacy amidst the things of sense, and hence i? derived in very truth the postulate of causation. 1 Max Miiller, LeeUires on the Science of Language, i. 506. XIV REASON AND CAUSE It is of the highest importance in the theory of knowledge to distinguish clearly between the two conceptions expressed by the terms Reason and Cause. And the distinction depends upon the true appreciation of the relations of the two activities of the organism — Thought and Exertion. In ordinary conversation, as Whateley pointed out, we constantly confound the two ideas. We say, " The reason of an eclipse of the sun is that the moon is interposed between it and the earth." In reality that is the cause of the eclipse, and the eclipse is the reason from which we infer the opera- tion of its cause. Descartes and many other metaphysicians failed to make the true discrimination. Schopenhauer has emphasised the importance of the distinction. According to him, the ancients constantly confounded the logical reason of know- ledge and the transcendental law of cause and effect in Nature ; a confusion probably traceable to the Platonic Doctrine of ideas with its failure REASON AND CAUSE 81 to appreciate the dynamic potency of Nature. The true distinction was most nearly reached by Aris- totle, who clearly distinguished between defining a thing and proving its existence. Spinoza habitually used Reason and Cause as inter- changeable terms. The result was that he became possessed of the idea that if we can determine the qualities of an idea, and if amongst them we include existence, we have established the reality of the thing which such Idea represents. The true distinction is at once seen when we recognise that in the inductive knowledge of Nature they stand in a constant inverse ratio to one another. Effects are the reasons from which we infer their causes. Causes are the conclusions which we deduce from their effects.' We say, " It has rained, because the ground is wet." The wetness of the ground is the sensible phenomenon, the effect, the reason, from which we infer the dynamic operation, " it was raining," as its cause. And this is the form of all inductive reasoning. " Because it is raining the ground must be wet." This is the form of deductive reasoning in which, just as from our exertional activity we deduce the properties of the lines, angles, and curves which are the results of such activity, we infer from the dynamic process, a fall of rain, the resulting , wetness of the ground. But whenever we apply this process to natural phenomena we must be fortified by a previous induction by which the causal nexus has been ascertained and estabUshed. 6 82 REASON AND CAUSE It is only when reasoning within the limits of our own potency, as in Geometry, that deduction can be directly employed.^ The result, the effect, of the dynamic operation is always the reason why we inductively infer that such operation took place. But that result is also the cause of our belief in such an operation. And it is this secondary view of the effect as a cause of knowledge that accounts for the ordinary con- versational habit and obscures from us the fact that reasons in knowledge correspond to effects in Nature and conclusions in knowledge to causes in Nature. ' ipiaei iiiv odv irpirepos xal yvwpi/uiTepos 6 Sia rod /Uirov avWoyur/ibs Tjfuv S ivapyiarepoi 6 Sii, rijs iirayayiis. Anal. Prior, ii. 23. Induction, the process which leads from EBect to Cause, affords to us the most palpable proof; but in Nature, i.e. following the process of Nature herself, the develop- ment of knowledge is by Deduction. XV THE TRUE ORIGIN OF THE POSTULATE The true origin of the postulate of the affirmative judgment should now be more evident. All agree that reality is a mental affirmation, but it does not necessarily follow that it derives its existence from thought. The affirmative judg- ment of the waking consciousness involves the two terms of a proposition. What is the predicate ? The true key is to be found, let us once again repeat, in the fact of my activity. My activity is twofold. I not only think, but at a much earlier stage I move; My motor energetic activity is apt to be confounded with its sensible results, but, regarded as an operation, it is the expression of a something which we call power. In calling that something power we are describing it by its efifeots. We are simply saying that action impUes that which acts, and that we shall call that which acts by a name connoting capacity for action. The essence of power, then, is capacity for action. Our activity amidst the things of sense is the activity of exertion. It implies power, it requires 84 THE TRUE ORIGIN OP THE POSTULATE power, it exhausts power, it uses up the transform- abihty of energy. And we postulate a similar power in the opponent. The sensible world is a kinesis. The actuality of phenomena is trans- mutation. Transmutation takes place in the face of opposition, and we postulate power as that which can effect the changes which do occur. When I say the horse draws the cart, what I funda- mentally mean by the horse is not the colours I associate with that name, but the potent agent which they represent. In like manner when I say the sun ripens the grain, or simply the sun shines, or when I describe any other physical change, I postulate as a cause the agent or unseen potent author of the transmutation. Even when I say something stands still, or merely exists, such stationary existence implies potency, a potency which sustains in their persistence the phenomenal changes whose constancy is embodied in its presen- tation. Solidity implies power, resistance implies power, even existence does the same. Everything which affects the senses involves the potency which enables it to do so. The permanencies of the sensible being all permanencies of change require to be sustained by power. That the reality of the cogitant ego is an inference from its activity was the proposition with which Descartes inaugurated modern philosophy. His famous maxim implies, not as is so often said, that my thought is the cause of my existence, but rather, that from the fact of my mental activity I THE TRUE ORIGIN OP THE POSTULATE 85 infer the reality of the cogitant ego as its cause. ' And in Uke manner from the facts of my exertional activity I postulate the agency of power. I recog- nise myself as potent to effect changes in the sensible environment ; ^ changes which, unlike the activities of thought, are effected in the face of opposition, and require power for their production ; and I therefore postulate a similar and homogeneous power as the sustainer of the environing opponent. The actual is possible as actuality in virtue of the potency in which it exists h ivmfjbu, and whose capacity for evolving itself into actuality made its actuality possible. So said Aristotle, and so says the latest science. Reality, then, as the subject of discourse is an affirmation ; but such affirmation is a representa- tion of dynamic activity as the potent sustainer of the sensible world. ' Referring to Dr. Thomas Brown's essay on Cause and Effect, Sir John Hersohell observed : " It is vitiated by one enormous over- sight, the omission, namely, of a distinct and immediate persona consciousness of causation in his enumeration of that sequence of events by which the volition of the mind is made to terminate in the motion of material objects. I mean the consciousness of effort as a thing entirely distinct from mere desire or volition on the one hand, and from mere spasmodic contraction of the muscles on the other." XVI THE IDEA OF MATERIALITY But if power is the true postulate, why has the conception of three-dimensioned materiality so long held the field ? To answer this question we must understand in what materiality consists. We should note that the advances of physical science within the last three hundred years have given to the word Matter a limitation of meaning — a restriction within the confines of the imperfect concepts of atoms and molecules — which it did not suffer when employed by those of earlier times. Bacon and others, in speaking of Matter, often mean rather what we should imply by " the physical." The contraction of the idea reached a climax when Heat and Light were distinguished from the material as Imponderable forms of the physical reality. It has been gradually broadening since. It now seems probable from a mere consideration of the elementary facts of sensible perception that smell is not occasioned by the bodily dissemina- tion of particles, but by some form of undulatory impulse. No one who reflects on the ordinary 86 THE IDEA OF MATERIALITY 87 phenomena of the radiation of heat from the soil — the ordinary changes which produce a frosty morning — can doubt that, apart altogether from the ether, the atmosphere is very inadequately described as composed of a collection of material particles. Still the idea of solid material particles as the basis of all physical phenomena for long appeared inevitable and intuitive, if not necessary. Any dynamical resolution of such a concept seemed to be vitiated by the fact that it was only by means of and on the assumption of such a postulate that dynamical reasoning could proceed. In the synthetic construction of the fabric of physical knowledge we easily and natiu-ally start from the datum of the sensible presentation, which, there- fore, in all such reasoning appears as its inevitable basis, the denial of which would be simply destruc- tive. But it is quite otherwise when we proceed analytically to investigate this basis itself. So proceeding, we find that these apparently basal concepts are, in fact, not simple but compound, that they are the product of a combination of visual and tangible impressions, with concepts representing our Activity. In the last analysis we have no right to assume the reality of material masses, however minute. Eliminating visual data which are obviously not fundamental, we find the basal features of materiality are all referable to the experiences of our Activity amidst the environing Powers of Nature. 88 THE IDEA OF MATERIALITY These powers or potencies of Nature, amidst all their multifarious variety, act not sporadically but constantly, and according to law. Recognising them by their operations amidst our sensible environment, we describe them as operations of natural force. The fundamental features of lit materiality we ascribe to the so-called forces of cohesion and gravity. We call them fundamental, and for us they are so, for they determine the phenomenon which we call body, and that in the last analysis is a constancy of energetic action which forms the condition precedent to our motional activity, indeed to our whole organic life. The transmutations of which such forces are manifesta- tions obey definite laws. These laws determine the fixed constancies we call bodies, — ^including our own. They determine the form of materiality, including its form as revealed in vision, — because the visual form directly corresponds to the dynamical form. In other words, spatial form is a discovery of our organic activity operating under the tensions of the physical system, and is the form or general law of such activity amidst such tensions. Our activity originates within this dynamic system. The operation of this process of trans- mutation is the precedent fact which generates and establishes the system of mobile masses in which materiality consists, and in which, therefore, organisms are possible. Matter, then, is phenomenal. Its constancy is but a constancy of certain forms THE IDEA OF MATERIALITY 89 of transinutation. Its elements, as Berkeley showed, are merely abstractions of sensible data. By such abstractions you cannot transcend these data themselves, but these constant processes, being the condition precedent to the existence of the organism, are for it fundamental. The postulation of matter, therefore, is no mere arbitrary expedient, but is directly based on the conditions of physical existence. None the less is it evident that materiality is not reality. Its so-called qualities are phenomenal. But the phen- omenon is a kinesis. It is, as we have seen, a transmutation. The form of materiality, there- fore, however phenomenal, is an expression of the laws which determine these transmutations. It partakes of the characters and expresses the inner nature of the real. But it is not itself Reality. It is a change which Reality undergoes. The true postulate, therefore, is power, not materiality. The qualities of matter, viewed as such, are unreal, but no such objection applies to the simple postulate of power. Power is no mere hypothetical abstraction of sensible forms competing with the vortex atoms, frictionless fluids, incompressible molecules, ethereal undulations, and other hypothetical explanations of the phenomena of nature. Potency is not an abstraction of sensible data at all. It is a pure noematical concept. Nor is it a speculative hypo- thesis. It is that conceptual postulate which every human being necessarily frames and uses during every day and every hour of his conscious life. 90 THE IDEA OF MATERIALITY because it is based on and suggested by that first of facts — his own constant activity — the very fact in virtue of which, and of which alone, we not only act but we reason and we seek to know — that very fact the recognition of which rather than any vain preference for the number one explains our constant effort to reduce the real to unity. This is the Aristotelian view of matter — a potency ever trans- muting itself into actuality, and containing within itself the capacity for such transmutation, — a reality which constantly undergoes transmutations, and of which the transmutations themselves con- stitute the phenomena of sense. All the fundamental qualities of matter are, therefore, discoverable in and derivable from our activity. Take its solidity and resistance. This quality is obviously discovered in the course of our exertional activity. From the sensations which accompany our exertion and which, so to speak, define it, we infer both the fact of our own potency and of oppos- ing power. And what are the features which we discover ? They are the features of the process in which materiality consists — the process of which the sensible manifestation is what we call cohesive force. But for the necessity we are under to overcome resistance, we should never discover these qualities or learn the fact of our own and our opponent's potency. Both are discovered together. The one implies the other. Potent agency is an inference which we make from such sensible experiences THE IDEA OF MATERIALITY 91 associated with our own activity. The process of sensible change is not sensation, but action. Thus our active experience is the basis of our ideas of resistance and solidity. Resistance is no doubt discovered in and by sensation. It is an idea de- scriptive of the fact that activity is impeded. Solidity is just another aspect of the same fact; though both terms are often employed to denote the sensible accompaniments of such obstructed action. It is important not to confound Mass with Resistance. The latter is a stress involving two opposing masses. It is altogether erroneous to import into the concept of Mass any of the sensible features from which the idea of Resistance is derived. In abstracting from the data of experience the element of massive materiality, many are apt merely to remove in thought all objects which resist our activity, and to forget that such ab- straction requires not only the removal of all opponent or resistant bodies but of our own organism also. Consideration should therefore make it clear that the elimination of the dynamical element of our experience carries with it mass and spatial extensity, in short, the whole basis of the Material World. The most fundamental quality of matter, how- ever, is probably felt to be its alleged indestructi- bility. Amidst all changes which it may undergo its quantity remains undiminished. This, then, is the primary and - immediate test of reality. But when once we realise that materiality is in essence 92 THE IDEA OF MATERIALITY a transmutation process, we readily apprehend the true significance of this proposition. It is the process which is constant ; and indestructible — at least by us its creatures. Apart from the operation of cohesion, massive materiality would not enter into our phenomenal system. No doubt in ordinary language we explain cohesion as a force of attraction between particles of matter, and such an explanation seems to presuppose their reality. But such particles are merely hypothetical postulates. From the standpoint of pure dynamics a datum of con- figuration is the starting-point from which the reasoning proceeds ; and stresses, conceived on the analogy of personal physical effort, are the stages which mark its progress. And in reasoning upon such sensible datum a force simply records the rate of transmutation, and a constant natural force the constant rate of a constant natural transmutation. The continuous and uniform operation of this trans- mutation process, giving rise to the phenomena of massive materiality, is the condition precedent to the actuality of those phenomenal groups which we call bodies. It is, therefore, the condition precedent to the operation of our activity, and of the opposing activities which involve us. Hence it is evident that matter must be by us indestructible — indeed, indestructible by any dynamic action within the system thus established. This is what indestructibihty means, and is all that it can mean. We cannot for a moment affirm that it is ultimately and absolutely impossible that THE IDEA OP MATERIALITY 93 matter should be destroyed. We do not, in point of fact, know that the quantity of matter in the universe is constant. Least of all is there any evidence for the assertion so gravely made by Schopenhauer that the destruction of matter is inconceivable. On the contrary, not only is it conceivable, but the total destruction of all matter has been an article of religious belief on the part of many just as much as its creation out of nothing. It is merely de- struction by our power or by the powers of Nature we know which is inconceivable. If what we mean by indestructibility of matter depends upon our taking a complete inventory of the universe, the ascertainment of the fact, if fact it be, is obviously hopeless, and the universality of the doctrine must be spurious. But if the doctrine is relative to our own potency and dependent on our knowledge of its limitations, its universality within such limits is both intelligible and ascertainable. It is true that, in ordinary dynamical reasoning about motion of mass, matter is often postulated as well as energy or power ; but that is so because the phenomena studied are motions of mass, that is, transmutations of energy which presuppose the transmutation in which mass consists. What is really postulated is merely a sensible datum of conjuration and certain supervening activities ; and all such reasoning can proceed, and does pro- ceed, in terms of energy transmutation without in- volving the postulate of the reality of any material substratum. 94 THE IDEA OF MATERIALITY From the standpoint of scientific observation, our physical organism being a mass, the transmutations of energy, in virtue of which massive phenomena occur, are the condition precedent to the study of motional change, and the assumption of these constancies as a datum marks the starting-point of the inquiry as it interests us as active agents therein. Hence the utility of the idea of materi- aUty. Hence its inevitable constant employment. But in thus displaying its true meaning and use, we at the same time illustrate its truly relative position with reference to reality.^ ' The energy of a mass in motion is usually termed kinetic. Our sensible experience is determined by the kinetic energies of our environment. But the energy of a mass, when that mass ceases to move, is never lost, but is transmuted into some other form. It may, for example, be transmuted into the kinetic energy of Heat. If, again, a body moving in opposition to Gravity is brought to rest, its energy becomes dormant and is denominated 'potential. The whole physical universe is in a state of tension due to the constant opera- tion of Natural Forces, and it is in virtue of such tension that a body has potential energy. The energy which a body at rest possesses in virtue of gravity and which we call its weight, is therefore one example of potential energy; the energy of chemical separation is another instance ; and the SoUdity or Besistance which a body possesses in virtue of what we are pleased to call Cohesion is a third. Speaking generally, it is to our consciousness of the persistence of potential energy that we must trace our deep-seated conviction of the " reaUty of Matter." Possibly, indeed, as has been suggested, all energy may be ultimately kinetic, but for practical purposes we cannot dispense with the useful and usual distinction between its kinetic and potential forms. XVII BXTBNSITY What has just been said of the idea of matter is equally true of space, — a concept which is simply the complement of the concept of matter and expresses our apprehension of the possibility of free mobility — an idea complementary to that of re- sistance, whilst the infinity of space simply ex- presses the almost identical proposition that within the system of massive materiality wherever activity is not limited by opposition it is unlimited and un- opposed. None the less is it remarkable how many of those who have studied the subject have failed to ap- preciate how the concept of space is formed and derived from the facts of our own activity. And if the derivation of the basal conception of space from the facts of our motor activity has been over- looked, it is equally remarkable how many have failed to perceive that the conception of the world which we construct with the aid of the data of vision is similarly composed. Apart from vision, Externality — ^mere otherness — 86 96 EXTENSITY is not qualified by extensity. Our conceptions of space are quantified by a reference to time, that is, to the intensity of the sensation by which our exer- tions are estimated. In vision we are presented with a multitude of sensible experiences simultaneously. Indeed we have a systematic simultaneous presentation of the principal features of the dynamic environment. Thus it is that visual space acquires the peculiar character which we call extensity. The efEective- ness of our Activity is thus greatly augmented. But it is still of the potent dynamic world that the visual scene is the presentation and the plan. Extensity results from the application of simul- taneity to activity. This view of the relation of extensity to vision is confirmed by an examination of the inferences in- volved in the act of vision, to which our working conceptions of matter and space are very largely indebted. The importance of vision was first recog- nised by Aristotle, but the most illuminative study of its meaning is to be found in Berkeley's famous Essay. Berkeley is generally credited with the discovery of the proposition that distance is not immediately given in vision, his reason being that the object of vision is a ray of light projected endwise on the eye. In point of fact Berkeley assumed this as self- evident, and proceeded on this assumption to develop his theory of vision. It would almost seem as if Berkeley had not EXTENSITY 97 appreciated the full Bignificance of his postulate, for if vision is effected by a line projected end- wise on the eye, it would seem as if it excluded extensity even in two dimensions or one. And it reaUy is true that spatial extensity in every form and degree is not an immediate datum of vision, but arises from the constant intellectual interpretation of visual data in terms of our activity. The original datum of vision is ascertainable by finding what is actually wanting to the totally blind, and that is found to be the colour sense only. The properties of externality in the three dimensions of solid geometrical figure are cognisable by the blind and can be taught to them. It follows that these properties need not be immediate data of vision ; and this implies a great deal more. It im- plies that there are ideas of spatial properties which are common to the blind and the vident. The knowledge of these properties is not, then, derived from the data of any of the senses, either touch, vision, or muscular sense. They are the pro- perties, the common laws, of our exertional activity amidst our environment. To the restored blind all objects at first seem " in the eye," or, rather, not projected at all. This is a tactual localisation, or localisation by tactual reference, because although the nerves of sight are not sensitive to touch any more than those of touch are to sight, it is probably suggested by the operation of the eyehd in shutting olBE and revealing the visible and thus affording a tactual reference. It is by reference to our activity 7 &8 EXTENSITY that we establish a visual association with exer- tional data. There is no other possible means whereby we can ascertain and determine the rela- tions in which visual sensations stand to tactual sensations. This co-ordination is accomplished by the ascertainment of the relation of visual sensa- tions with tactual sensations not immediately felt at the moment but brought into consciousness by active exertion on our part. By reference to ex- ertion and touch we discover the visual co-relatives of tangible resistant bodies. By similar exertions we ascertain the amount of effort which has to be made in order to pass from one such sensation to another, and hence arises the notion of distance. In exertional experience the co-relation is primarily by means of the time reference. The simultaneous- ness of the visual presentation converts this refer- ence into what we call spatial extensity. It is difficult at first to realise that extensity is not necessarily given in vision. But so it is. The notion of extensity arises because visual data are presented simultaneously, and are utilised as the unfailing symbols and guides of our activity. A multifarious combination of sounds does not similarly suggest extensity, but no doubt would do so if sounds were used as the constant guides of action. If our world, if our plans of action, were arranged by reference to the sounds emitted by environing objects, the various sounds would gradually acquire a relation of the nature of visual extensity. EXTENSITY 99 In pure vision it would at first appear evident that form is immediately given. Is not the round globe of the sun or the form of this rectangular page given immediately in vision ? We reply yes, but such form is not