# Matter and Memory/Chapter 4

THE DELIMITING AND FIXING OF IMAGES. PERCEPTION AND MATTER. SOUL AND BODY.
One general conclusion follows from the first three chapters of this book: it is that the body,The fundamental law of psychical life is the orientation of consciousness towards action. always turned towards action, has for its essential function to limit, with a view to action, the life of the spirit. In regard to representations it is an instrument of choice, and of choice alone. It can neither beget nor cause an intellectual state. Consider perception, to begin with. The body, by the place which at each moment it occupies in the universe, indicates the parts and the aspects of matter on which we can lay hold: our perception, which exactly measures our virtual action on things, thus limits itself to the objects which actually influence our organs and prepare our movements. Now let us turn to memory. The function of the body is not to store up recollections, but simply to choose, in order to bring back to distinct consciousness, by the real efficacy thus conferred on it, the useful memory, that which may complete and illuminate the present situation with a ​view to ultimate action. It is true that this second choice is much less strictly determined than the first, because our past experience is an individual and no longer a common experience, because we have always many different recollections equally capable of squaring with the same actual situation, and because nature cannot here, as in the case of perception, have one inflexible rule for delimiting our representations. A certain margin is, therefore, necessarily left in this case to fancy; and though animals scarcely profit by it, bound as they are to material needs, it would seem that the human mind ceaselessly presses with the totality of its memory against the door which the body may half open to it: hence the play of fancy and the work of imagination—so many liberties which the mind takes with nature. It is none the less true that the orientation of our consciousness towards action appears to be the fundamental law of our psychical life.
Strictly, we might stop here, for this work was undertaken to define the function of the body in the life of the spirit. But, on the one hand, we have raised by the way a metaphysical problem which we cannot bring ourselves to leave in suspense; and on the other, our researches, although mainly psychological, have on several occasions given us glimpses, if not of the means of solving the problem, at any rate of the side on which it should be approached.
This problem is no less than that of the union of ​soul and body. It comes before us clearly andA true psychology, distinguishing between spirit and matter, yet suggests the manner of their union. with urgency, because we make a profound distinction between matter and spirit. And we cannot regard it as insoluble, since we define spirit and matter by positive characters, and not by negations. It is in very truth within matter that pure perception places us, and it is really into spirit that we penetrate by means of memory. But on the other hand, whilst introspection reveals to us the distinction between matter and spirit, it also bears witness to their union. Either, then, our analyses are vitiated ab origine, or they must help us to issue from the difficulties that they raise.
The obscurity of this problem, in all doctrines, is due to the double antithesis which our understandingDifficulties caused by the double antithesis; in extension and quality in the perceiving mind; the extended and quality in the perceived universe. establishes between the extended and the unextended on the one side, between quality and quantity on the other. It is certain that mind, first of all, stands over against matter as a pure unity in face of an essentially divisible multiplicity; and moreover that our perceptions are composed of heterogeneous qualities, whereas the perceived universe seems to resolve itself into homogeneous and calculable changes. There would thus be inextension and quality on the one hand, extensity and quantity on the other. We have repudiated materialism, which derives the first term ​from the second; but neither do we accept idealism, which holds that the second is constructed by the first. We maintain, as against materialism, that perception overflows infinitely the cerebral state; but we have endeavoured to establish, as against idealism, that matter goes in every direction beyond our representation of it, a representation which the mind has gathered out of it, so to speak, by an intelligent choice. Of these two opposite doctrines, the one attributes to the body and the other to the intellect a true power of creation, the first insisting that our brain begets representation and the second that our understanding designs the plan of nature. And against these two doctrines we invoke the same testimony, that of consciousness, which shows us our body as one image among others and our understanding as a certain faculty of dissociating, of distinguishing, of opposing logically, but not of creating or of constructing. Thus, willing captives of psychological analysis and consequently of common sense, it would seem that, after having exacerbated the conflicts raised by ordinary dualism, we have closed all the avenues of escape which metaphysic might set open to us.
But, just because we have pushed dualism to an extreme, our analysis has perhaps dissociated its contradictory elements. The theory of pure perception on the one hand, of pure memory on the other, may thus prepare the way for a reconcili​ation between the unextended and the extended, between quality and quantity.
To take pure perception first. When we make the cerebral state the beginning of an action, and inBut since pure perception is a part of things, these share in the nature of perception: the idea of extension. no sense the condition of a perception we place the perceived images of things outside the image of our body, and thus replace perception within the things themselves. But then, our perception being a part of things, things participate in the nature of our perception. Material extensity is not, cannot any longer be, that composite extensity which is considered in geometry; it indeed resembles rather the undivided extension of our own representation. That is to say that the analysis of pure perception allows us to foreshadow in the idea of extension the possible approach to each other of the extended and the unextended.
But our conception of pure memory should lead us, by a parallel road, to attenuate the secondAnd the heterogeneity of sensible qualities is due to their contraction in memory: the idea of tension. opposition, that of quality and quantity. For we have radically separated pure recollection from the cerebral state which continues it and renders it efficacious. Memory is, then, in no degree an emanation of matter; on the contrary, matter, as grasped in concrete perception which always occupies a certain duration, is in great part the work of memory. Now where is, precisely, the difference between the heterogeneous ​qualities which succeed each other in our concrete perception and the homogeneous changes which science puts at the back of these perceptions in space? The first are discontinuous and cannot be deduced one from another; the second, on the contrary, lend themselves to calculation. But, in order that they may lend themselves to calculation, there is no need to make them into pure quantities: we might as well say that they are nothing at all. It is enough that their heterogeneity should be, so to speak, sufficiently diluted to become, from our point of view, practically negligible. Now, if every concrete perception, however short we suppose it, is already a synthesis, made by memory, of an infinity of 'pure perceptions' which succeed each other, must we not think that the heterogeneity of sensible qualities is due to their being contracted in our memory, and the relative homogeneity of objective changes to the slackness of their natural tension? And might not the interval between quantity and quality be lessened by considerations of tension, as the distance between the extended and the unextended is lessened by considerations of extension?
Before entering on this question, let us formulate the general principle of the method we would apply. We have already made use of it in an earlier work and even, by implication, in the present essay.
That which is commonly called a fact is not ​reality as it appears to immediate intuition, butThe method of philosophy. Objects and facts. have been carved out of reality. Philosophy must get back to reality itself. an adaptation of the real to the interests of practice and to the exigencies of social life. Pure intuition, external or internal, is that of an undivided continuity. We break up this continuity into elements laid side by side, which correspond in the one case to distinct words, in the other to independent objects. But, just because we have thus broken the unity of our original intuition, we feel ourselves obliged to establish between the severed terms a bond which can only then be external and superadded. For the living unity, which was one with internal continuity, we substitute the factitious unity of an empty diagram as lifeless as the parts which it holds together. Empiricism and dogmatism are, at bottom, agreed in starting from phenomena so reconstructed; they differ only in that dogmatism attaches itself more particularly to the form and empiricism to the matter. Empiricism, feeling indeed, but feeling vaguely, the artificial character of the relations which unite the terms together, holds to the terms and neglects the relations. Its error is not that it sets too high a value on experience, but that it substitutes for true experience, that experience which arises from the immediate contact of the mind with its object, an experience which is disarticulated and therefore, most probably, disfigured,—at any rate arranged for the greater ​facility of action and of language. Just because this parcelling of the real has been effected in view of the exigencies of practical life, it has not followed the internal lines of the structure of things: for that very reason empiricism cannot satisfy the mind in regard to any of the great problems and, indeed, whenever it becomes fully conscious of its own principle, it refrains from putting them.—Dogmatism discovers and disengages the difficulties to which empiricism is blind; but it really seeks the solution along the very road that empiricism has marked out. It accepts, at the hands of empiricism, phenomena that are separate and discontinuous, and simply endeavours to effect a synthesis of them which, not having been given by intuition, cannot but be arbitrary. In other words, if metaphysic is only a construction, there are several systems of metaphysic equally plausible, which consequently refute each other, and the last word must remain with a critical philosophy, which holds all knowledge to be relative and the ultimate nature of things to be inaccessible to the mind. Such is, in truth, the ordinary course of philosophic thought: we start from what we take to be experience, we attempt various possible arrangements of the fragments which apparently compose it, and when at last we feel bound to acknowledge the fragility of every edifice that we have built, we end by giving up all effort to build. But there is a last enterprise that might be undertaken. It would be to ​seek experience at its source, or rather above that decisive turn where, taking a bias in the direction of our utility, it becomes properly human experience. The impotence of speculative reason, as Kant has demonstrated it, is perhaps at bottom only the impotence of an intellect enslaved to certain necessities of bodily life, and concerned with a matter which man has had to disorganize for the satisfaction of his wants. Our knowledge of things would thus no longer be relative to the fundamental structure of our mind, but only to its superficial and acquired habits, to the contingent form which it derives from our bodily functions and from our lower needs. The relativity of knowledge may not, then, be definitive. By unmaking that which these needs have made, we may restore to intuition its original purity and so recover contact with the real.
This method presents, in its application, difficulties which are considerable and ever recurrent, because it demands for the solution of each new problem an entirely new effort. To give up certain habits of thinking, and even of perceiving, is far from easy: yet this is but the negative part of the work to be done; and when it is done, when we have placed ourselves at what we have called the turn of experience, when we have profited by the faint light which, illuminating the passage from the immediate to the useful, marks the dawn of our human experience, there still remains to be reconstituted, with the infinitely small elements which ​we thus perceive of the real curve, the curve itself stretching out into the darkness behind them. In this sense the task of the philosopher, as we understand it, closely resembles that of the mathematician who determines a function by starting from the differential. The final effort of philosophical research is a true work of integration.
We have already attempted to apply this method to the problem of consciousness; and it appeared to us that the utilitarian work of the mind, in what concerns the perception of our inner life, consisted in a sort of refracting of pure duration into space, a refracting which permits us to separate our psychical states, to reduce them to a more and more impersonal form and to impose names upon them,—in short, to make them enter the current of social life. Empiricism and dogmatismBut empiricism and dogmatism alike take reality in a discontinuous form, ignoring duration. take interior states in this discontinuous form; the first confining itself to the states themselves, so that it can see in the self only a succession of juxtaposed facts; the other grasping the necessity of a bond, but unable to find this bond anywhere except in a form or in a force,—an exterior form into which the aggregate is inserted, an indetermined and so to speak physical force which assures the cohesion of the elements. Hence the two opposing points of view as to the question ​of freedom: for determinism the act is the resultant of a mechanical composition of the elements; for the adversaries of that doctrine, if they adhered strictly to their principle, the free decision would be an arbitrary fiat, a true creation ex nihilo.—It seemed to us that a third course lay open. This is to replace ourselves in pure duration, of which the flow is continuous and in which we pass insensibly from one state to another: a continuity which is really lived, but artifically decomposed for the greater convenience of customary knowledge. Then, it seemed to us, we saw the action issue from its antecedents by an evolution sui generis, in such a way that we find in this action the antecedents which explain it, while it yet adds to these something entirely new, being an advance upon them such as the fruit is upon the flower. Freedom is not hereby, as has been asserted, reduced to sensible spontaneity. At most this would be the case in the animal, of which the psychical life is mainly affective. But in man, the thinking being, the free act may be termed a synthesis of feelings and ideas, and the evolution which leads to it a reasonable evolution. The artifice of this method simply consists, in short, in distinguishing the point of view of customary or useful knowledge from that of true knowledge. The duration wherein we see ourselves acting, and in which it is useful that we should see ourselves, is a duration whose elements are dissociated and juxtaposed. The duration wherein we act is a duration wherein ​our states melt into each other. It is within this that we should try to replace ourselves by thought, in the exceptional and unique case when we speculate on the intimate nature of action, that is to say, when we are discussing human freedom.
Is a method of this kind applicable to the problem of matter? The question is, whether, in this 'diversity of phenomena' of which Kant spoke, that part which shows a vague tendency towards extension could be seized by us on the hither side of the homogeneous space to which it is applied and through which we subdivide it,—just as that part which goes to make up ourAnd they equally ignore that extension, concrete and undivided, beneath which we stretch out an artificial space. own inner life can be detached from time, empty and indefinite, and brought back to pure duration. Certainly it would be a chimerical enterprise to try to free ourselves from the fundamental conditions of external perception. But the question is whether certain conditions, which we usually regard as fundamental, do not rather concern the use to be made of things, the practical advantage to be drawn from them, far more than the pure knowledge which we can have of them. More particularly, in regard to concrete extension, continuous, diversified and at the same time organized, we do not see why it should be bound up with the amorphous and inert space which subtends it—a space which we divide indefinitely, out of which we carve figures arbitrarily, and in which movement itself, as we have ​said elsewhere, can only appear as a multiplicity of instantaneous positions, since nothing there can ensure the coherence of past with present. It might, then, be possible, in a certain measure, to transcend space without stepping out from extensity; and here we should really have a return to the immediate, since we do indeed perceive extensity, whereas space is merely conceived,—being a kind of mental diagram. It may be urged against this method that it arbitrarily attributes a privileged value to immediate knowledge? But what reasons should we have for doubting any knowledge,—would the idea of doubting it ever occur to us,—but for the difficulties and the contradictions which reflexion discovers, but for the problems which philosophy poses? And would not immediate knowledge find in itself its justification and proof, if we could show that these difficulties, contradictions and problems are mainly the result of the symbolic diagrams which cover it up, diagrams which have for us become reality itself, and beyond which only an intense and unusual effort can succeed in penetrating?
Let us choose at once, among the results to which the application of this method may lead, those which concern our present enquiry. We must confine ourselves to mere suggestions; there can be no question here of constructing a theory of matter.
I.—Every movement, inasmuch as it is a passage from rest to rest, is absolutely indivisible.
This is not an hypothesis, but a fact, generally masked by an hypothesis.
Here, for example, is my hand, placed at the point A. I carry it to the point B, passing at one stroke through the interval between them. There are two things in this movement: an image which I see, and an act of which my muscular sense makes my consciousness aware. My consciousness gives me the inward feeling of a single fact, for in A was rest, in B there is again rest, and between A and B is placed an indivisible or at least an undivided act, the passage from rest toMovement is indivisible; it is only the trajectory of a moving body that is divisible. rest, which is movement itself. But my sight perceives the movement in the form of a line AB which is traversed, and this line, like all space, may be indefinitely divided. It seems then, at first sight, that I may at will take this movement to be multiple or indivisible, according as I consider it in space or in time, as an image which takes shape outside of me or as an act which I am myself accomplishing.
Yet, when I put aside all preconceived ideas, I soon perceive that I have no such choice, that even my sight takes in the movement from A to B as an indivisible whole, and that if it divides anything, it is the line supposed to have been traversed, and not the movement traversing it. It is indeed ​true that my hand does not go from A to B without passing through the intermediate positions, and that these intermediate points resemble stages, as numerous as you please, all along the route; but there is, between the divisions so marked out and stages properly so called, this capital difference, that at a stage we halt, whereas at these points the moving body passes. Now a passage is a movement and a halt is an immobility. The halt interrupts the movement; the passage is one with the movement itself. When I see the moving body pass any point, I conceive, no doubt, that it might stop there; and even when it does not stop there, I incline to consider its passage as an arrest, though infinitely short, because I must have at least the time to think of it; but it is only my imagination which stops there, and what the moving body has to do is, on the contrary, to move. As every point of space necessarily appears to me fixed, I find it extremely difficult not to attribute to the moving body itself the immobility of the point with which, for a moment, I make it coincide; it seems to me, then, when I reconstitute the total movement, that the moving body has stayed an infinitely short time at every point of its trajectory. But we must not confound the data of the senses, which perceive the movement, with the artifice of the mind, which recomposes it. The senses, left to themselves, present to us the real movement, between two real halts, as a solid ​and undivided whole. The division is the work of our imagination, of which indeed the office is to fix the moving images of our ordinary experience, like the instantaneous flash which illuminates a stormy landscape by night.
We discover here, at its outset, the illusion which accompanies and masks the perception of real movement. Movement visibly consists in passing from one point to another, and consequently in traversing space. Now the space which is traversed is infinitely divisible; and as the movement is, so to speak, applied to the line along which it passes, it appears to be one with this line and, like it, divisible. Has not the movement itself drawn the line? Has it not traversed in turn the successive and juxtaposed points of that line? Yes, no doubt, but these points have no reality except in a line drawn, that is to say motionless; and by the very fact that you represent the movement to yourself successively in these different points, you necessarily arrest it in each of them; your successive positions are, at bottom, only so many imaginary halts. You substitute the path for the journey, and because the journey is subtended by the path you think that the two coincide. But how should a progress coincide with a thing, a movement with an immobility?
What facilitates this illusion is that we distinguish moments in the course of duration, like halts in the passage of the moving body. Even ​if we grant that the movement from one point to another forms an undivided whole, this movement nevertheless takes a certain time; so that if we carve out of this duration an indivisible instant, it seems that the moving body must occupy, at that precise moment, a certain position, which thus stands out from the whole. The indivisibility of motion implies, then, the impossibility of real instants; and indeed, a very brief analysis of the idea of duration will show us both why we attribute instants to duration and why it cannot have any. Suppose a simple movement like that of my hand when it goes from A to B. This passage is given to my consciousness as an undivided whole. No doubt it endures; but this duration, which in fact coincides with the aspect which the movement has inwardly for my consciousness, is, like it, whole and undivided. Now, while it presents itself, qua movement, as a simple fact, it describes in space a trajectory which I may consider, for purposes of simplification, as a geometrical line; and the extremities of this line, considered as abstract limits, are no longer lines, but indivisible points. Now, if the line, which the moving body has described, measures for me the duration of its movement, must not the point, where the line ends, symbolize for me a terminus of this duration? And if this point is an indivisible of length, how shall we avoid terminating the duration of the movement by an indivisible of duration? If ​the total line represents the total duration, the parts of the line must, it seems, correspond to parts of the duration, and the points of the line to moments of time. The indivisibles of duration, or moments of time, are born, then, of the need of symmetry; we come to them naturally as soon as we demand from space an integral presentment of duration.—But herein, precisely, lies the error. While the line AB symbolizes the duration already lapsed of the movement from A to B already accomplished, it cannot, motionless, represent the movement in its accomplishment nor duration in its flow. And from the fact that this line is divisible into parts and that it ends in points, we cannot conclude either that the corresponding duration is composed of separate parts or that it is limited by instants.
The arguments of Zeno of Elea have no other origin than this illusion. They all consist inZeno transfers to the moving body the properties of its trajectory: hence all the difficulties and contradictions making time and movement coincide with the line which underlies them, in attributing to them the same subdivisions as to the line, in short in treating them like that line. In this confusion Zeno was encouraged by common sense, which usually carries over to the movement the properties of its trajectory, and also by language, which always translates movement and duration in terms of space. But common sense and language have a right to do so ​and are even bound to do so, for, since they always regard the becoming as a thing to be made use of, they have no more concern with the interior organization of movement than a workman has with the molecular structure of his tools. In holding movement to be divisible, as its trajectory is, common sense merely expresses the two facts which alone are of importance in practical life: first, that every movement describes a space; second, that at every point of this space the moving body might stop. But the philosopher who reasons upon the inner nature of movement is bound to restore to it the mobility which is its essence, and this is what Zeno omits to do. By the first argument (the Dichotomy) he supposes the moving body to be at rest, and then considers nothing but the stages, infinite in number, that are along the line to be traversed: we cannot imagine, he says, how the body could ever get through the interval between them. But in this way he merely proves that it is impossible to construct, à priori, movement with immobilities, a thing no man ever doubted. The sole question is whether, movement being posited as a fact, there is a sort of retrospective absurdity in assuming that an infinite number of points has been passed through. But at this we need not wonder, since movement is an undivided fact, or a series of undivided facts, whereas the trajectory is infinitely divisible. In the second argument (the Achilles) movement is ​indeed given, it is even attributed to two moving bodies, but, always by the same error, there is an assumption that their movement coincides with their path, and that we may divide it, like the path itself, in any way we please. Then, instead of recognizing that the tortoise has the pace of a tortoise and Achilles the pace of Achilles, so that after a certain number of these indivisible acts or bounds Achilles will have outrun the tortoise, the contention is that we may disarticulate as we will the movement of Achilles and, as we will also, the movement of the tortoise: thus reconstructing both in an arbitrary way, according to a law of our own which may be incompatible with the real conditions of mobility. The same fallacy appears, yet more evident, in the third argument (the Arrow) which consists in the conclusion that, because it is possible to distinguish points on the path of a moving body, we have the right to distinguish indivisible moments in the duration of its movement. But the most instructive of Zeno's arguments is perhaps the fourth (the Stadium) which has, we believe, been unjustly disdained, and of which the absurdity is more manifest only because the postulate masked in the three others is here frankly displayed. Without entering on a dis​cussion which would here be out of place, we will content ourselves with observing that motion, as given to spontaneous perception, is a fact which is quite clear, and that the difficulties and contradictions pointed out by the Eleatic school concern far less the living movement itself than a dead and artificial reorganization of movement by the mind. But we now come to the conclusion of all the preceding paragraphs:
​II. There are real movements.
The mathematician, expressing with greater precision an idea of common sense, defines positionMovement is relative only for the mathematician, real for the physicist. by the distance from points of reference or from axes, and movement by the variation of the distance. Of movement, then, he only retains changes in length; and as the absolute values of the variable distance between a point and an axis, for instance, express either the displacement of the axis with regard to the point or that of the point with regard to the axis, just as we please, he attributes indifferently to the same point repose or motion. If, then, movement is nothing but a change of distance, the same object is in motion or motionless according to the points to which it is referred, and there is no absolute movement.
But things wear a very different aspect when we pass from mathematics to physics, and from the abstract study of motion to a consideration of the concrete changes occurring in the universe. Though we are free to attribute rest or motion to any material point taken by itself, it is none the less true that the aspect of the material universe changes, that the internal configuration of every real system varies, and that here we have no longer the choice between mobility and rest. Movement, whatever its inner nature, becomes an indisputable reality. We may not be able to say what parts of the whole are in motion; ​motion there is in the whole, none the less. Therefore it is not surprising that the same thinkers, who maintain that every particular movement is relative, speak of the totality of movements as of an absolute. The contradiction has been pointed out in Descartes, who, after having given to the thesis of relativity its most radical form by affirming that all movement is 'reciprocal,' formulated the laws of motion as though motion were an absolute. Leibniz and others after him have remarked this contradiction: it is due simply to the fact that Descartes handles motion as a physicist after having defined it as a geometer. For the geometer all movement is relative: which signifies only, in our view, that none of our mathematical symbols can express the fact that it is the moving body which is in motion rather than the axes or the points to which it is referred. And this is very natural, because these symbols, always meant for measurement, can express only distances. But that there is real motion no one can seriously deny: if there were not, nothing in the universe would change; and, above all, there would be no meaning in the consciousness which we have of our own movements. In his controversy with Descartes Henry More makes jesting allusion to this last ​point: 'When I am quietly seated, and another, going a thousand paces away, is flushed with fatigue, it is certainly he who moves and I who am at rest.'
But if there is absolute motion, is it possible to persist in regarding movement as nothing but a change of place? We should thenIf there are any real movements, they cannot be merely changes of positions. have to make diversity of place into an absolute difference, and distinguish absolute positions in an absolute space. Newton went as far as this, followed moreover by Euler and by others. But can this be imagined, or even conceived? A place could be absolutely distinguished from another place only by its quality or by its relation to the totality of space: so that space would become, on this hypothesis, either composed of heterogeneous parts or finite. But to finite space we should give another space as boundary, and beneath heterogeneous parts of space we should imagine an homogeneous space as its foundation: in both cases it is to homogeneous and indefinite space that we should necessarily return. We cannot, then, hinder ourselves either from holding every place to be relative, or from believing some motion to be absolute.
It may be urged that real movement is distinguished from relative movement in that it ​has a real cause, that it emanates from a force. But we must understand what we mean by this last word. In natural science force is only a function of mass and velocity: it is measured by acceleration: it is known and estimated only by the movements which it is supposed to produce in space. One with these movements, it shares their relativity. Hence the physicists, who seek the principle of absolute motion in force so defined, are led by the logic of their system back to the hypothesis of an absolute space which they had at first desired to avoid. So it will become necessary to take refuge in the metaphysical sense of the word, and attribute the motion which we perceive in space to profound causes, analogous to those which our consciousness believes it discovers within the feeling of effort. But is the feeling of effort really the sense of a profound cause? Have not decisive analyses shown that there is nothing in this feeling other than the consciousness of movements already effected or begun at the periphery of the body? It is in vain, then, that we seek to found the reality of motion on a cause which is distinct from it: analysis always brings us back to motion itself.
But why seek elsewhere? So long as we apply a movement to the line along which it passes, the same point will appear to us, by turns, according to the points or the axes to which we ​refer it, either at rest or in movement. But it is otherwise if we draw out of the movement the mobility which is its essence. When my eyes give me the sensation of a movement, this sensation is a reality, and something is effectually going on, whether it be that an object is changing its place before my eyes or that my eyes are moving before the object. A fortiori am I assured of the reality of the movement when I produce it after having willed to produce it, and my muscular sense brings me the consciousness of it. That is to say, I grasp the reality of movement when it appears to me, within me, as a change of state or of quality. But then how should it be otherwise when I perceive changes of quality in things? Sound differs absolutely from silence, as also one sound from another sound. Between light and darkness, between colours, between shades, the difference is absolute. The passage from one to another is also an absolutely real phenomenon. I hold then the two ends of the chain, muscular sensations within me, the sensible qualities of matter without me, and neither in the one case nor in the other do I see movement, if there be movement, as a mere relation: it is an absolute. Now, between these two extremities lie the movements of external bodies, properly so called. How are we to distinguish here between real and apparent movement? Of what object, externally perceived, can it be said that it moves, of what other that it remains motionless? To put ​such a question is to admit that the discontinuity established by common sense between objects independent of each other, having each its individuality, comparable to kinds of persons, is a valid distinction. For, on the contrary hypothesis, the question would no longer be how are produced in given parts of matter changes of position, but how is effected in the whole a change of aspect,—a change of which we should then have to ascertain the nature. Let us then formulate at once our third proposition:—
III. All division of matter into independent bodies with absolutely determined outlines is an artificial division.
A body, that is, an independent material object, presents itself at first to us as a system of qualitiesThe division of matters into distinct bodies is no datum of immediate intuition, nor yet a demand of science, if we consider science in its remotest aspirations. in which resistance and colour—the data of sight and touch—occupy the centre, all the rest being, as it were, suspended from them. On the other hand, the data of sight and touch are those which most obviously have extension in space, and the essential character of space is continuity. There are intervals of silence between sounds, for the sense of hearing is not always occupied; between odours, between tastes, there are gaps, as though the senses of smell and taste only functioned accidentally: as soon as we open our eyes, on the contrary, the whole field of vision takes on colour; and, since solids are necessarily in contact with each other, our touch must follow ​the surface or the edges of objects without ever encountering a true interruption. How do we parcel out the continuity of material extensity, given in primary perception, into bodies of which each is supposed to have its substance and individuality? No doubt the aspect of this continuity changes from moment to moment; but why do we not purely and simply realize that the whole has changed, as with the turning of a kaleidoscope? Why, in short, do we seek, in the mobility of the whole, tracks that are supposed to be followed by bodies supposed to be in motion? A moving continuity is given to us, in which everything changes and yet remains: whence comes it that we dissociate the two terms, permanence and change, and then represent permanence by bodies and change by homogeneous movements in space? This is no teaching of immediate intuition; but neither is it a demand of science, for the object of science is, on the contrary, to rediscover the natural articulations of a universe we have carved artificially. Nay more, science, as we shall see, by an evermore complete demonstration of the reciprocal action of all material points upon each other, returns, in spite of appearances, to the idea of an universal continuity. Science and consciousness are agreed at bottom, provided that we regard consciousness in its most immediate data, and science in its remotest aspirations. Whence comes then the irresistible tendency to set up a material universe that is discontinuous, composed ​of bodies which have clearly defined outlines and change their place, that is, their relation with each other?
Besides consciousness and science, there is life. Beneath the principles of speculation, so carefullyIt is the necessities of living, i.e. of action, that mark out for consciousness distinct bodies. analysed by philosophers, there are tendencies of which the study has been neglected, and which are to be explained simply by the necessity of living, that is, of acting. Already the power conferred on the individual consciousness of manifesting itself in acts requires the formation of distinct material zones, which correspond respectively to living bodies: in this sense my own body and, by analogy with it, all other living bodies are those which I have the most right to distinguish in the continuity of the universe. But this body itself, as soon as it is constituted and distinguished, is led by its various needs to distinguish and constitute other bodies. In the humblest living being nutrition demands research, then contact, in short a series of efforts which converge towards a centre: this centre is just what is made into an object—the object which will serve as food. Whatever be the nature of matter, it may be said that life will at once establish in it a primary discontinuity, expressing the duality of the need and of that which must serve to satisfy it. But the need of food is not the only need. Others group themselves round it, all having for object the ​conservation of the individual or of the species; and each of them leads us to distinguish, besides our own body, bodies independent of it which we must seek or avoid. Our needs are, then, so many search-lights which, directed upon the continuity of sensible qualities, single out in it distinct bodies. They cannot satisfy themselves except upon the condition that they carve out, within this continuity, a body which is to be their own, and then delimit other bodies with which the first can enter into relation, as if with persons. To establish these special relations among portions thus carved out from sensible reality is just what we call living.
But if this first subdivision of the real answers much less to immediate intuition than to theBut, to get a philosophical theory of matter, we must reject customary images framed by practical needs. fundamental needs of life, are we likely to gain a nearer knowledge of things by pushing the division yet further? In this way we do indeed prolong the vital movement; but we turn our back upon true knowledge. That is why the rough and ready operation, which consists in decomposing the body into parts of the same nature as itself, leads us down a blind alley, where we soon feel ourselves incapable of conceiving either why this division should cease or how it could go on ad infinitum. It is nothing, in fact, but the ordinary condition of useful action, unsuitably transported into the domain of pure knowledge. We shall never explain by means of ​particles, whatever these may be, the simple properties of matter: at most we can thus follow out into corpuscles as artificial as the corpus—the body itself—the actions and reactions of this body with regard to all the others. This is precisely the object of chemistry. It studies bodies rather than matter; and so we understand why it stops at the atom, which is still endowed with the general properties of matter. But the materiality of the atom dissolves more and more under the eyes of the physicist. We have no reason, for instance, for representing the atom to ourselves as a solid, rather than as liquid or gaseous, nor for picturing the reciprocal action of atoms by shocks rather than in any other way. Why do we think of a solid atom, and why of shocks? Because solids, being the bodies on which we clearly have the most hold, are those which interest us most in our relations with the external world; and because contact is the only means which appears to be at our disposal in order to make our body act upon other bodies. But very simple experiments show that there is never true contact between two neighbouring bodies; and besides, solidity is far from being an absolutely defined state of matter. Solidity and shock borrow, then, their apparent clearness ​from the habits and necessities of practical life;—images of this kind throw no light on the inner nature of things.
Moreover, if there is a truth that science has placed beyond dispute, it is that of the reciprocal action of all parts of matter upon each other. Between the supposed molecules of bodies the forces of attraction and repulsion are at work. The influence of gravitation extends throughout interplanetary space. Something, then, exists between the atoms. It will be said that this something is no longer matter, but force. And we shall be asked to picture to ourselves, stretched between the atoms, threads which will be made more and more tenuous, until they are invisible and even, we are told, immaterial. But what purpose can this crude image serve? The preservation of life no doubt requires that we should distinguish, in our daily experience, between passive things and actions effected by these things in space. As it is useful to us to fix the seat of the thing at the precise point where we might touch it, its palpable outlines become for us its real limit, and we then see in its action a something, I know not what, which, being altogether different, can part company with it. But since a theory of matter is an attempt to find the reality hidden beneath these customary images which are entirely relative to our needs, from these images it must first of all set itself free. And, indeed, we see force and matter drawing nearer together the ​more deeply the physicist has penetrated into their effects. We see force more and more materialized, the atom more and more idealized, the two terms converging towards a common limit and the universe thus recovering its continuity. We may still speak of atoms; the atom may even retain its individuality for our mind which isolates it; but the solidity and the inertia of the atom dissolve either into movements or into lines of force whose reciprocal solidarity brings back to us universal continuity. To this conclusion were bound to come, though they started from very different positions, the two physicists of the last century who have most closely investigated the constitution of matter, Lord Kelvin and Faraday. For Faraday the atom is a centre of force. He means by this that the individuality of the atom consists in the mathematical point at which cross, radiating throughout space, the indefinite lines of force which really constitute it: thus each atom occupies the whole space to which gravitation extends and all atoms are interpenetrating. Lord Kelvin, moving in another order of ideas, supposes a perfect, continuous, homogeneous and incompressible fluid, filling space: what we term an atom he makes into a vortex ring, ever whirling in this continuity, and owing its properties to its circular form, its existence and consequently ​its individuality to its motion. But on either hypothesis, the nearer we draw to the ultimate elements of matter the better we note the vanishing of that discontinuity which our senses perceived on the surface. Psychological analysis has already revealed to us that this discontinuity is relative to our needs: every philosophy of nature ends by finding it incompatible with the general properties of matter.
In truth, vortices and lines of force are never, to the mind of the physicist, more than convenient figures for illustrating his calculations. But philosophy is bound to ask why these symbols are more convenient than others, and why they permit of further advance. Could we, working with them, get back to experience, if the notions to which they correspond did not at least point out the direction in which we may seek for a representation of the real? Now the direction which they indicate is obvious; they show us, pervading concrete extensity, modifications, perturbations, changes of tension or of energy, and nothing else. It is by this, above all, that they tend to unite with the purely psychological analysis of motion which we considered to begin with, an analysis which presented it to us not as a mere change of relation between objects to which it was, as it ​were, an accidental addition, but as a true and, in some sort, an independent, reality. Neither science nor consciousness, then, is opposed to this last proposition:—
IV. Real movement is rather the transference of a state than of a thing.
By formulating these four propositions, we have, in reality, only been progressively narrowingSo we shall see real movement as rather quality than quantity, and, as such, akin to consciousness. the interval between the two terms which it is usual to oppose to each other,—qualities or sensations, and movements. At first sight, the distance appears impassable. Qualities are heterogeneous, movements homogeneous. Sensations, essentially indivisible, escape measurement; movements, always divisible, are distinguished by calculable differences of direction and velocity. We are fain to put qualities, in the form of sensations, in consciousness; while movements are supposed to take place independently of us in space. These movements, compounded together, we confess, will never yield anything but movements; our consciousness, though incapable of coming into touch with them, yet by a mysterious process is said to translate them into sensations, which afterwards project themselves into space and come to overlie, we know not how, the movements they translate. Hence two different worlds, incapable of communicating otherwise than by a miracle,—on the one hand that of motion ​in space, on the other that of consciousness with sensations. Now, certainly the difference is irreducible (as we have shown in an earlier work) between quality on the one hand and pure quantity on the other. But this is just the question: do real movements present merely differences of quantity, or are they not quality itself, vibrating, so to speak, internally, and beating time for its own existence through an often incalculable number of moments? Motion, as studied in mechanics, is but an abstraction or a symbol, a common measure, a common denominator, permitting the comparison of all real movements with each other; but these movements, regarded in themselves, are indivisibles which occupy duration, involve a before and an after, and link together the successive moments of time by a thread of variable quality which cannot be without some likeness to the continuity of our own consciousness. May we not conceive, for instance, that the irreducibility of two perceived colours is due mainly to the narrow duration into which are contracted the billions of vibrations which they execute in one of our moments? If we could stretch out this duration, that is to say, live it at a slower rhythm, should we not, as the rhythm slowed down, see these colours pale and lengthen into successive impressions, still coloured, no doubt, but nearer and nearer to coincidence ​with pure vibrations? In cases where the rhythm of the movement is slow enough to tally with the habits of our consciousness,—as in the case of the deep notes of the musical scale, for instance,—do we not feel that the quality perceived analyses itself into repeated and successive vibrations, bound together by an inner continuity? That which usually hinders this mutual approach of motion and quality is the acquired habit of attaching movement to elements—atoms or what not,—which interpose their solidity between the movement itself and the quality into which it contracts. As our daily experience shows us bodies in motion, it appears to us that there ought to be, in order to sustain the elementary movements to which qualities may be reduced, diminutive bodies or corpuscles. Motion becomes then for our imagination no more than an accident, a series of positions, a change of relations; and, as it is a law of our representation that in it the stable drives away the unstable, the important and central element for us becomes the atom, between the successive positions of which movement then becomes a mere link. But not only has this conception the inconvenience of merely carrying over to the atom all the problems raised by matter; not only does it wrongly set up as an absolute that division of matter which, in our view, is hardly anything but an outward projection of human needs; it also renders unintelligible the process by which we grasp, in perception, at one and the same time, a ​state of our consciousness and a reality independent of ourselves. This mixed character of our immediate perception, this appearance of a realized contradiction, is the principal theoretical reason that we have for believing in an external world which does not coincide absolutely with our perception. As it is overlooked in the doctrine that regards sensation as entirely heterogeneous with movements, of which sensation is then supposed to be only a translation into the language of consciousness, this doctrine ought, it would seem, to confine itself to sensations, which it had indeed begun by setting up as the actual data, and not add to them movements which, having no possible contact with them, are no longer anything but their useless duplicate. Realism, so understood, is self-destructive. Indeed, we have no choice: if our belief in a more or less homogeneous substratum of sensible qualities has any ground, this can only be found in an act which makes us seize or divine, in quality itself, something which goes beyond sensation, as if this sensation itself were pregnant with details suspected yet unperceived. Its objectivity—that is to say, what it contains over and above what it yields up—must then consist, as we have foreshadowed, precisely in the immense multiplicity of the movements which it executes, so to speak, within itself as a chrysalis. Motionless on the surface, in its very depth it lives and vibrates.
As a matter of fact, no one represents to himself ​the relation between quantity and quality in anyWhilst in quality itself we may divine something other than sensation, i.e. the multiplicity of the movements contracted in the rhythm of our own duration. other way. To believe in realities, distinct from that which is perceived, is above all to recognize that the order of our perceptions depends on them and not on us. There must be, then, within the perceptions which fill a given moment, the reason of what will happen in the following moment. And mechanism only formulates this belief with more precision when it affirms that the states of matter can be deduced one from the other. It is true that this deduction is possible only if we discover, beneath the apparent heterogeneity of sensible qualities, homogeneous elements which lend themselves to calculation. But, on the other hand, if these elements are external to the qualities of which they are meant to explain the regular order, they can no longer render the service demanded of them, because then the qualities must be supposed to come to overlie them by a kind of miracle, and cannot correspond to them unless we bring in some pre-established harmony. So, do what we will, we cannot avoid placing those movements within these qualities, in the form of internal vibrations, and then considering the vibrations as less homogeneous, and the qualities as less heterogeneous, than they appear, and lastly attributing the difference of aspect in the two terms to the necessity which lies upon what may be called an endless multiplicity of contracting ​into a duration too narrow to permit of the separation of its moments.
We must insist on this last point, to which we have already alluded elsewhere, and which weThere may be as many tensions of duration as there are degrees of consciousness. regard as essential. The duration lived by our consciousness is a duration with its own determined rhythm, a duration very different from the time of the physicist, which can store up, in a given interval, as great a number of phenomena as we please. In the space of a second, red light,—the light which has the longest wave-length, and of which, consequently, the vibrations are the least frequent—accomplishes 400 billions of successive vibrations. If we would form some idea of this number, we should have to separate the vibrations sufficiently to allow our consciousness to count them, or at least to record explicitly their succession; and we should then have to enquire how many days or months or years this succession would occupy. Now the smallest interval of empty time which we can detect equals, according to Exner, 1/500 of a second; and it is even doubtful whether we can perceive in succession several intervals as short as this. Let us admit, however, that we can go on doing so indefinitely. Let us imagine, in a word, a consciousness which should watch the succession of 400 billions of vibrations, each instantaneous, and each separated from the next only by the 1/500 of a second necessary to distinguish them. ​A very simple calculation shows that more than 25,000 years would elapse before the conclusion of the operation. Thus the sensation of red light, experienced by us in the course of a second, corresponds in itself to a succession of phenomena which, separately distinguished in our duration with the greatest possible economy of time, would occupy more than 250 centuries of our history. Is this conceivable? We must distinguish here between our own duration and time in general. In our duration,—the duration which our consciousness perceives,—a given interval can only contain a limited number of phenomena of which we are aware. Do we conceive that this content can increase; and when we speak of an infinitely divisible time, is it our own duration that we are thinking of?
As long as we are dealing with space, we may carry the division as far as we please; we change in no way, thereby, the nature of what is divided. This is because space, by definition, is outside us; it is because a part of space appears to us to subsist even when we cease to be concerned with it; so that, even when we leave it undivided, we know that it can wait, and that a new effort of our imagination may decompose it when we choose. As, moreover, it never ceases to be space, it always implies juxtaposition and consequently possible division. Abstract space is, indeed, at bottom, nothing but the mental diagram of infinite divisibility. But with duration it is quite otherwise. The parts of ​our duration are one with the successive moments of the act which divides it; if we distinguish in it so many instants, so many parts it indeed possesses; and if our consciousness can only distinguish in a given interval a definite number of elementary acts, if it terminates the division at a given point, there also terminates the divisibility. In vain does our imagination endeavour to go on, to carry division further still, and to quicken, so to speak, the circulation of our inner phenomena: the very effort by which we are trying to effect this further division of our duration lengthens that duration by just so much. And yet we know that millions of phenomena succeed each other while we hardly succeed in counting a few. We know this not from physics alone; the crude experience of the senses allows us to divine it; we are dimly aware of successions in nature much more rapid than those of our internal states. How are we to conceive them, and what is this duration of which the capacity goes beyond all our imagination?
It is not ours, assuredly; but neither is it that homogeneous and impersonal duration, the same for everything and for every one, which flows onward, indifferent and void, external to all that endures. This imaginary homogeneous time is, as we have endeavoured to show elsewhere, an idol of language, a fiction of which the origin is ​easy to discover. In reality there is no one rhythm of duration; it is possible to imagine many different rhythms which, slower or faster, measure the degree of tension or relaxation of different kinds of consciousness, and thereby fix their respective places in the scale of being. To conceive of durations of different tensions is perhaps both difficult and strange to our mind, because we have acquired the useful habit of substituting for the true duration, lived by consciousness, an homogeneous and independent Time; but, in the first place, it is easy, as we have shown, to detect the illusion which renders such a thought foreign to us, and, secondly, this idea has in its favour, at bottom, the tacit agreement of our consciousness. Do we not sometimes perceive in ourselves, in sleep, two contemporaneous and distinct persons of whom one sleeps a few minutes, while the other's dream fills days and weeks? And would not the whole of history be contained in a very short time for a consciousness at a higher degree of tension than our own, which should watch the development of humanity while contracting it, so to speak, into the great phases of its evolution? In short, then, to perceive consists in condensing enormous periods of an infinitely diluted existence into a few more differentiated moments of an intenser life, and in thus summing up a very long history. To perceive means to immobilize.
To say this is to say that we seize, in the ​act of perception, something which outruns perception Our consciousness sums up for us whole periods of the inner history of things. itself, although the material universe is not essentially different or distinct from the representation which we have of it. In one sense, my perception is indeed truly within me, since it contracts into a single moment of my duration that which, taken in itself, spreads over an incalculable number of moments. But, if you abolish my consciousness, the material universe subsists exactly as it was; only, since you have removed that particular rhythm of duration which was the condition of my action upon things, these things draw back into themselves, mark as many moments in their own existence as science distinguishes in it; and sensible qualities, without vanishing, are spread and diluted in an incomparably more divided duration. Matter thus resolves itself into numberless vibrations, all linked together in uninterrupted continuity, all bound up with each other, and travelling in every direction like shivers through an immense body.—In short, try first to connect together the discontinuous objects of daily experience; then resolve the motionless continuity of their qualities into vibrations on the spot; finally fix your attention on these movements, by abstracting from the divisible space which underlies them and considering only their mobility (that undivided act which our consciousness becomes aware of in our own movements): you will thus obtain a ​vision of matter, fatiguing perhaps for your imagination, but pure, and freed from all that the exigencies of life compel you to add to it in external perception.—Now bring back consciousness, and with it the exigencies of life: at long, very long, intervals, and by as many leaps over enormous periods of the inner history of things, quasi-instantaneous views will be taken, views which this time are bound to be pictorial, and of which the more vivid colours will condense an infinity of elementary repetitions and changes. In just the same way the multitudinous successive positions of a runner are contracted into a single symbolic attitude, which our eyes perceive, which art reproduces, and which becomes for us all the image of a man running. The glance which falls at any moment on the things about us only takes in the effects of a multiplicity of inner repetitions and evolutions, effects which are, for that very reason, discontinuous, and into which we bring back continuity by the relative movements that we attribute to 'objects' in space. The change is everywhere, but inward; we localize it here and there, but outwardly; and thus we constitute bodies which are both stable as to their qualities and mobile as to their positions, a mere change of place summing up in itself, to our eyes, the universal transformation.
That there are, in a sense, multiple objects, that one man is distinct from another man, tree from tree, stone from stone, is an indisputable ​fact; for each of these beings, each of theseNecessity would rule a being that adopted the rhythm of the duration of matter. By condensing that duration into our own, we conquer necessity, things, has characteristic properties and obeys a determined law of evolution. But the separation between a thing and his environment cannot be absolutely definite and clear cut; there is a passage by insensible gradations from the one to the other: the close solidarity which binds all the objects of the material universe, the perpetuity of their reciprocal actions and reactions, is sufficient to prove that they have not the precise limits which we attribute to them. Our perception outlines, so to speak, the form of their nucleus; it terminates them at the point where our possible action upon them ceases, where, consequently, they cease to interest our needs. Such is the primary and the most apparent operation of the perceiving mind: it marks out divisions in the continuity of the extended, simply following the suggestions of our requirement and the needs of practical life. But, in order to divide the real in this manner, we must first persuade ourselves that the real is divisible at will. Consequently we must throw beneath the continuity of sensible qualities, that is to say, beneath concrete extensity, a network, of which the meshes may be altered to any shape whatsoever and become as small as we please: this substratum which is merely conceived, this wholly ideal diagram of arbitrary and infinite divisibility, is homogeneous space.—Now, at the same ​time that our actual and so to speak instantaneous perception effects this division of matter into independent objects, our memory solidifies into sensible qualities the continuous flow of things. It prolongs the past into the present, because our action will dispose of the future in the exact proportion in which our perception, enlarged by memory, has contracted the past. To reply, to an action received, by an immediate reaction which adopts the rhythm of the first and continues it in the same duration, to be in the present and in a present which is always beginning again,—this is the fundamental law of matter: herein consists necessity. If there are actions that are really free, or at least partly indeterminate, they can only belong to beings able to fix, at long intervals, that becoming to which their own becoming clings, able to solidify it into distinct moments, and so to condense matter and, by assimilating it, to digest it into movements of reaction which will pass through the meshes of natural necessity. The greater or less tension of their duration, which expresses, at bottom, their greater or less intensity of life, thus determines both the degree of the concentrating power of their perception and the measure of their liberty. The independence of their action upon surrounding matter becomes more and more assured in the degree that they free themselves from the particular rhythm which governs the flow of this matter. So that sensible qualities, as they are ​found in our memory-shot perception, are in fact the successive moments obtained by a solidification of the real. But, in order to distinguish these moments, and also to bind them together by a thread which shall be common alike to our own existence and to that of things, we are bound to imagine a diagrammatic design of succession in general, an homogeneous and indifferent medium, which is to the flow of matter in the sense of length as space is to it in the sense of breadth: herein consists homogeneous time.
Homogeneous space and homogeneous time are then neither properties of things nor essentialHomogeneous space and time are the mental diagrams of our eventual action upon matter; they are not properties of things. conditions of our faculty of knowing them: they express, in an abstract form, the double work of solidification and of division which we effect on the moving continuity of the real in order to obtain there a fulcrum for our action, in order to fix within it starting-points for our operation, in short, to introduce into it real changes. They are the diagrammatic design of our eventual action upon matter. The first mistake, that which consists in viewing this homogeneous time and space as properties of things, leads to the insurmountable difficulties of metaphysical dogmatism,—whether mechanistic or dynamistic,—dynamism erecting into so many absolutes the successive cross-cuts which we make in the course of the universe as it flows along, and then endeavouring vainly ​to bind them together by a kind of qualitative deduction; mechanism attaching itself rather, in any one of these cross-cuts, to the divisions made in its breadth, that is to say, to instantaneous differences in magnitude and position, and striving no less vainly to produce, by the variation of these differences, the succession of sensible qualities. Shall we then seek refuge in the other hypothesis, and maintain, with Kant, that space and time are forms of our sensibility? If we do, we shall have to look upon matter and spirit as equally unknowable. Now, if we compare these two hypotheses, we discover in them a common basis: by setting up homogeneous time and homogeneous space either as realities that are contemplated or as forms of contemplation, they both attribute to space and time an interest which is speculative rather than vital. Hence there is room, between metaphysical dogmatism on the one hand and critical philosophy on the other, for a doctrine which regards homogeneous space and time as principles of division and of solidification introduced into the real with a view to action and not with a view to knowledge, which attributes to things a real duration and a real extensity, and which, in the end, sees the source of all difficulty no longer in that duration and in that extensity (which really belong to things and are directly manifest to the mind), but in the homogeneous space and time which we stretch out beneath them in order to divide the continuous, to fix the ​becoming, and provide our activity with points to which it can be applied.
But erroneous conceptions about sensible quality and about space are so deeply rooted in the mindQualities of different orders share in extensity, though in different degrees. that it is important to attack them from every side. We may say then, to reveal yet another aspect, that they imply this double postulate, accepted equally by realism and by idealism: first, that between different kinds of qualities there is nothing common; second, that neither is there anything common between extensity and pure quality. We maintain, on the contrary, that there is something common between qualities of different orders, that they all share in extensity, though in different degrees, and that it is impossible to overlook these two truths without entangling in a thousand difficulties the metaphysic of matter, the psychology of perception and, more generally, the problem of the relation of consciousness with matter. Without insisting on these consequences, let us content ourselves for the moment with showing, at the bottom of the various theories of matter, the two postulates which we dispute and the illusion from which they proceed.
The essence of English idealism is to regard extensity as a property of tactile perceptions. As it sees nothing in sensible qualities but sensations, and in sensations themselves nothing but mental states, it finds in the different qualities ​nothing on which to base the parallelism ofIdealism and realism both regard the different orders of sensation as discontinuous, and so miss the true nature of perception. their phenomena. It is therefore constrained to account for this parallelism by a habit which makes the actual perceptions of sight, for instance, suggest to us potential sensations of touch. If the impressions of two different senses resemble each other no more than the words of two languages, we shall seek in vain to deduce the data of the one from the data of the other. They have no common element; and consequently, there is nothing common between extensity, which is always tactile, and the data of the senses other than that of touch, which must then be supposed to be in no way extended. But neither can atomistic realism, which locates movements in space and sensations in consciousness, discover anything in common between the modifications or phenomena of extensity and the sensations which correspond to them. Sensations are supposed to issue from the modifications as a kind of phosphorescence, or, again, to translate into the language of the soul the manifestations of matter; but in neither case do they reflect, we are told, the image of their causes. No doubt they may all be traced to a common origin, which is movement in space; but, just because they develop outside of space, they must forego, qua sensations, the kinship which binds their causes together. In breaking with space they break also their connexion with each other; they ​have nothing in common between them, nor with extensity.
Idealism and realism, then, only differ in that the first relegates extensity to tactile perception, of which it becomes the exclusive property, while the second thrusts extensity yet further back, outside of all perception. But the two doctrines are agreed in maintaining the discontinuity of the different orders of sensible qualities, and also the abrupt transition from that which is purely extended to that which is not extended at all. Now the principal difficulties which they both encounter in the theory of perception arise from this common postulate.
For suppose, to begin with, as Berkeley did, that all perception of extensity is to be referred to the sense of touch. We may, indeed, if you will have it so, deny extension to the data of hearing, smell and taste; but we must at least explain the genesis of a visual space that corresponds to tactile space. It is alleged, indeed, that sight ends by becoming symbolic of touch, and that there is nothing more in the visual perception of the order of things in space than a suggestion of tactile perception. But we fail to understand how the visual perception of relief, for instance, a perception which makes upon us an impress sui generis, and indeed indescribable, could ever be one with the mere remembrance of a sensation of touch. The association of a memory with a present perception may complicate ​this perception by enriching it with an element already known, but it cannot create a new kind of impress, a new quality of perception: now the visual perception of relief presents an absolutely original character. It may be urged that it is possible to give the illusion of relief with a plane surface. This only proves that a surface, on which the play of light and shadow on an object in relief is more or less well imitated, is enough to remind us of relief; but how could we be reminded of relief if relief had not been, at first, actually perceived? We have already said, but we cannot repeat too often, that our theories of perception are entirely vitiated by the idea that if a certain arrangement produces, at a given moment, the illusion of a certain perception, it must always have been able to produce the perception itself;—as if the very function of memory were not to make the complexity of the effect survive the simplification of the cause! Again, it may be urged that the retina itself is a plane surface, and that if we perceive by sight something that is extended, it can only be the image on the retina. But is it not true, as we have shown at the beginning of this book, that in the visual perception of an object the brain, nerves, retina and the object itself form a connected whole, a continuous process in which the image on the retina is only an episode? By what right, then, do we isolate this image to sum up in it the whole of percep​tion? And then, as we have also shown, how could a surface be perceived as a surface otherwise than in a space that has recovered its three dimensions? Berkeley, at least, carried out his theory to its conclusion; he denied to sight any perception of extensity. But the objections which we raised only acquire the more force from this, since it is impossible to understand the spontaneous creation, by a mere association of memories, of all that is original in our visual perceptions of line, surface and volume, perceptions so distinct that the mathematician does not go beyond them and works with a space that is purely visual. But we will not insist on these various points, nor on the disputable arguments drawn from the observation of those, born blind, whose sight has been surgically restored: the theory of the acquired perceptions of sight, classical since Berkeley's day, does not seem likely to resist the multiplied attacks of contemporary psychology. Passing over the difficulties of a psychological order, we will content ourselves with drawing attention to another point, in our opinion essential. Suppose for a moment that ​the eye does not, at the outset, give us any information as to any of the relations of space. Visual form, visual relief, visual distance, then become the symbols of tactile perceptions. But how is it, then, that this symbolism succeeds? Here are objects which change their shape and move. Vision takes note of definite changes which touch afterwards verifies. There is, then, in the two series, visual and tactile, or in their causes, something which makes them correspond one to another and ensures the constancy of their parallelism. What is the principle of this connexion?
For English idealism, it can only be some deus ex machina, and we are confronted with a mystery again. For ordinary realism, it is in a space distinct from the sensations themselves that the principle of the correspondence of sensations one with another lies; but this doctrine only throws the difficulty further back and even aggravates it, for we shall now want to know how a system of homogeneous movements in space evokes various sensations which have no resemblance whatever with them. Just now the genesis of visual perception of space by a mere association of images appeared to us to imply a real creation ex nihilo; here all the sensations are born of nothing, or at least have no resemblance with the movement that occasions them. In the main, this second theory differs much less from the first than is commonly believed. ​Amorphous space, atoms jostling against each other, are only our tactile perceptions made objective, set apart from all our other perceptions on account of the special importance which we attribute to them, and made into independent realities,—thus contrasting with the other sensations which are then supposed to be only the symbols of these. Indeed, in the course of this operation, we have emptied these tactile sensations of a part of their content; after having reduced all other senses to being mere appendages of the sense of touch, touch itself we mutilate, leaving out everything in it that is not a mere abstract or diagrammatic design of tactile perception: with this design we then go on to construct the external world. Can we wonder that between this abstraction on the one hand, and sensations on the other, no possible link is to be found? But the truth is that space is no more without us than within us, and that it does not belong to a privileged group of sensations. All sensations partake of extensity; all are more or less deeply rooted in it; and the difficulties of ordinary realism arise from the fact that, the kinship of the sensations one with another having been extracted and placed apart under the form of an indefinite and empty space, we no longer see either how these sensations can partake of extensity or how they can correspond with each other.
Contemporary psychology is more and more ​impressed with the idea that all our sensationsBut modern psychology has a tendency to regard all sensation as primarily extensive. are in some degree extensive. It is maintained, not without an appearance of reason, that there is no sensation without extensity or without a feeling 'of volume.' English idealism sought to reserve to tactile perception a monopoly of the extended, the other senses dealing with space only in so far as they remind us of the data of touch. A more attentive psychology reveals to us, on the contrary, and no doubt will hereafter reveal still more clearly, the need of regarding all sensations as primarily extensive, their extensity fading and disappearing before the higher intensity and usefulness of tactile, and also, no doubt, of visual, extensity.
So understood, space is indeed the symbol of fixity and of infinite divisibility. ConcreteWe invert reality when we regard rest as logically anterior to motion, space as the necessary antecedent to movements. extensity, that is to say the diversity of sensible qualities, is not within space; rather is it space that we thrust into extensity. Space is not a ground on which real motion is posited; rather is it real motion that deposits space beneath itself. But our imagination, which is preoccu​pied above all by the convenience of expression and the exigencies of material life, prefers to invert the natural order of the terms. Accustomed to seek its fulcrum in a world of readymade motionless images, of which the apparent fixity is hardly anything else but the outward reflexion of the stability of our lower needs, it cannot help believing that rest is anterior to motion, cannot avoid taking rest as its point of reference and its abiding place, so that it comes to see movement as only a variation of distance, space being thus supposed to precede motion. Then, in a space which is homogeneous and infinitely divisible, we draw, in imagination, a trajectory and fix positions: afterwards, applying the movement to the trajectory, we see it divisible like the line we have drawn, and equally denuded of quality. Can we wonder that our understanding, working thenceforward on this idea, which represents precisely the reverse of the truth, discovers in it nothing but contradictions? Having assimilated movements to space, we find these movements homogeneous like space; and since we no longer see in them anything but calculable differences of direction and velocity, all relation between movement and quality is for us destroyed. So that all we have to do is to shut up motion in space, qualities in consciousness, and ​to establish between these two parallel series, incapable, by hypothesis, of ever meeting, a mysterious correspondence. Thrown back into consciousness, sensible qualities become incapable of recovering extensity. Relegated to space, and indeed to abstract space, where there is never but a single instant and where everything is always being born anew—movement abandons that solidarity of the present with the past which is its very essence. And as these two aspects of perception, quality and movement, have been made equally obscure, the phenomenon of perception, in which a consciousness, assumed to be shut up in itself and foreign to space, is supposed to translate what occurs in space, becomes a mystery.—But let us, on the contrary, banish all preconceived idea of interpreting or measuring, let us place ourselves face to face with immediate reality: at once we find that there is no impassable barrier, no essential difference, no real distinction even, between perception and the thing perceived, between quality and movement.
So we return, by a round-about way, to the conclusions worked out in the first chapter of this book. Our perception, we said, is originally in things rather than in the mind, without us rather than within. The several kinds of perception correspond to so many directions actually marked out in reality. But, we added, this ​perception, which coincides with its object, exists rather in theory than in fact: it could only happen if we were shut up within the present moment. In concrete perception memory intervenes, and the subjectivity of sensible qualities is due precisely to the fact that our consciousness, which begins by being only memory, prolongs a plurality of moments into each other, contracting them into a single intuition.
Consciousness and matter, body and soul, were thus seen to meet each other in perception. ButPerception and matter reveal their kinship as we lay aside the prejudices of action. in one aspect this idea remained for us obscure, because our perception, and consequently also our consciousness, seemed thus to snare in the divisibility which is attributed to matter. If, on the dualistic hypothesis, we naturally shrink from accepting the partial coincidence of the perceived object and the perceiving subject, it is because we are conscious of the undivided unity of our perception, whereas the object appears to us to be, in essence, infinitely divisible. Hence the hypothesis of a consciousness with inextensive sensations, placed over against an extended multiplicity. But if the divisibility of matter is entirely relative to our action thereon, that is to say to our faculty of modifying its aspect, if it belongs not to matter itself but to the space which we throw beneath this matter in order to bring it within our grasp, then the difficulty disappears. Extended matter, regarded as a whole, is like a ​consciousness where everything balances and compensates and neutralizes everything else; it possesses in very truth the indivisibility of our perception; so that, inversely, we may without scruple attribute to perception something of the extensity of matter. These two terms, perception and matter, approach each other in the measure that we divest ourselves of what may be called the prejudices of action: sensation recovers extensity, the concrete extended recovers its natural continuity and indivisibility. And homogeneous space, which stood between the two terms like an insurmountable barrier, is then seen to have no other reality than that of a diagram or a symbol. It interests the behaviour of a being which acts upon matter, but not the work of a mind which speculates on its essence.
Thereby also some light may be thrown upon the problem towards which all our enquiriesOrdinary dualism, regarding matter as exclusively spatial, and mind as extra spatial, severs all communication between them. converge, that of the union of body and soul. The obscurity of this problem, on the dualistic hypothesis, comes from the double fact that matter is considered as essentially divisible and every state of the soul as rigorously inextensive, so that from the outset the communication between the two terms is severed. And when we go more deeply into this double postulate, we discover, in regard to matter, a confusion of concrete and indivisible extensity with the divisible space which underlies it; and ​also, in regard to mind, the illusory idea that there are no degrees, no possible transition, between the extended and the unextended. But if these two postulates involve a common error, if there is a gradual passage from the idea to the image and from the image to the sensation; if, in the measure in which it evolves towards actuality, that is to say towards action, the mental state draws nearer to extension; if, finally, this extension once attained remains undivided and therefore is not out of harmony with the unity of the soul; we can understand that spirit can rest upon matter and consequently unite with it in the act of pure perception, yet nevertheless be radically distinct from it. It is distinct from matter in that it is, even then, memory, that is to say a synthesis of past and present with a view to the future, in that it contracts the moments of this matter in order to use them and to manifest itself by actions which are the final aim of its union with the body. We were right, then, when we said, at the beginning of this book, that the distinction between body and mind must be established in terms not of space but of time.
The mistake of ordinary dualism is that it starts from the spatial point of view: it puts on the one hand matter with its modifications in space, on the other unextended sensations in consciousness. Hence the impossibility of understanding how the spirit acts upon the body or the body upon spirit. Hence hypotheses which are ​and can be nothing but disguised statements of the fact,—the idea of a parallelism or of a pre-established harmony. But hence also the impossibility of constituting either a psychology of memory or a metaphysic of matter. We have striven to show that this psychology and this metaphysic are bound up with each other, and that the difficulties are less formidable in a dualism which, starting from pure perception, where subject and object coincide, follows the development of the two terms in their respective durations,—matter, the further we push its analysis, tending more and more to be only a succession of infinitely rapid moments which may be deduced each from the other and thereby are equivalent to each other; spirit being in perception already memory, and declaring itself more and more as a prolonging of the past into the present, a progress, a true evolution.
But does the relation of body and mind become thereby clearer? We substitute a temporal forBut the distinction between mind and matter should be made in terms not of space, but of time or duration, which admits of degrees. a spatial distinction: are the two terms any the more able to unite? It must be observed that the first distinction does not admit of degree: matter is supposed to be in space, spirit to be extra-spatial; there is no possible transition between them. But if, in fact, the humblest function of spirit is to bind together the successive moments of the duration of things, if it is by this that it comes into contact with matter and by this also that it is first ​of all distinguished from matter, we can conceive an infinite number of degrees between matter and fully developed spirit—a spirit capable of action which is not only undetermined, but also reasonable and reflective. Each of these successive degrees, which measures a growing intensity of life, corresponds to a higher tension of duration and is made manifest externally by a greater development of the sensori-motor system. But let us consider this nervous system itself: we note that its increasing complexity appears to allow an ever greater latitude to the activity of the living being, the faculty of waiting before reacting, and of putting the excitation received into relation with an ever richer variety of motor mechanisms. Yet this is only the outward aspect; and the more complex organization of the nervous system, which seems to assure the greater independence of the living being in regard to matter, is only the material symbol of that independence itself, that is to say of the inner energy which allows the being to free itself from the rhythm of the flow of things, and to retain in an ever higher degree the past in order to influence ever more deeply the future,—the symbol, in the special sense which we give to the word, of its memory. Thus, between brute matter and the mind most capable of reflexion there are all possible intensities of memory or, what comes to the same thing, all the degrees of freedom. On the first hypothesis, that which expresses the distinction be​tween spirit and body in terms of space, body and spirit are like two railway lines which cut each other at a right angle; on the second, the rails come together in a curve, so that we pass insensibly from the one to the other.
But have we here anything but a metaphor? Does not a marked distinction, an irreducible opposition, remain between matter properly so-called and the lowest degree of freedom or of memory? Yes, no doubt, the distinction subsists, but union becomes possible, since it would be given, under the radical form of a partial coincidence, in pure perception. The difficulties of ordinary dualism come, not from the distinction of the two terms, but from the impossibility of seeing how the one is grafted upon the other. Now, as we have shown, pure perception, which is the lowest degree of mind,—mind without memory—is really part of matter, as we understand matter. We may go further: memory does not intervene as a function of which matter has no presentiment and which it does not imitate in its own way. If matter does not remember the past, it is because it repeats the past unceasingly, because, subject to necessity, it unfolds a series of moments of which each is the equivalent of the preceding moment and may be deduced from it: thus its past is truly given in its present. But a being which evolves more or less freely creates something new every moment: in vain, then, should we seek to read its past in its present ​unless its past were deposited within it in the form of memory. Thus, to use again a metaphor which has more than once appeared in this book, it is necessary, and for similar reasons, that the past should be acted by matter, imagined by mind.
* ↑ Time and Free Will, H. Bergson. Published by Sonnenschein & Co. Translation of Les données immédiates de la conscience.
* ↑ We may here briefly recall this argument. Let there be a moving body which is displaced with a certain velocity, and which passes simultaneously before two bodies, one at rest and the other moving towards it with the same velocity as its own. During the same time that it passes a certain length of the first body, it naturally passes double that length of the other. Whence Zeno concludes that 'a duration is the double of itself.' A childish argument, it is said, because Zeno takes no account of the fact that the velocity is in the one case double that which it is in the other.—Certainly, but how, I ask, could he be aware of this? That, in the same time, a moving body passes different lengths of two bodies, of which one is at rest and the other in motion, is clear for him who makes of duration a kind of absolute, and places it either in consciousness or in something which partakes of consciousness. For while a determined portion of this absolute or conscious duration elapses, the same moving body will traverse, as it passes the two bodies, two spaces of which the one is the double of the other, without our being able to conclude from this that a duration is double itself, since duration remains independent of both spaces. But Zeno's error, in all his reasoning, is due to just this fact, that he leaves real duration on one side, and considers only its objective track in space. How then should the two lines traced by the same moving body not merit an equal consideration, qua measures of duration? And how should they not represent the same duration, even though the one is twice the other? In concluding from this that 'a duration is the double of itself,' Zeno was true to the logic of his hypothesis; and his fourth argument is worth exactly as much as the three others.
* ↑ Descartes, Principes, ii, 29.
* ↑ Principes, part ii, § 37 et seq.
* ↑ Leibniz, Specimen dynamicum (Mathem. Schriften, Gerhardt, 2nd section, vol. ii, p. 246).
* ↑ H. Morus, Scripta Philosophica, 1679, vol. ii, p. 248.
* ↑ Newton, Principia, Ed. Thomson, 1871, p. 6 et seq.
* ↑ Euler, Theoria motus corporum solidorum, 1765, pp. 30–33.
* ↑ Newton, in particular.
* ↑ See, on this subject, Clerk-Maxwell, Action at a Distance (Scientific Papers, Cambridge, 1890, vol. ii pp. 313–314).
* ↑ Clerk-Maxwell, Molecular Constitution of Bodies (Scientific Papers, vol. ii, p. 618).—Van der Waals has shown, on the other hand, the continuity of liquid and gaseous states.
* ↑ Faraday, A Speculation concerning Electric Conduction (Philos. Magazine, 3rd series, vol. xxiv).
* ↑ Thomson, On Vortex Atoms (Proc. of the Roy. Soc. of Edin., 1867). An hypothesis of the same nature had been put forward by Graham, On the Molecular Mobility of Gases (Proc. of the Roy. Soc., 1863, p. 621 et seq.).
* ↑ H. Bergson, Time and Free Will. Sonnenschein & Co.
* ↑ H. Bergson, Time and Free Will. Sonnenschein & Co.
* ↑ Time and Free Will. Sommenschein & Co., 1910.
* ↑ See on this subject: Paul Janet, La perception visuelle de la distance, Revue philosophique, 1879, vol. vii, p. 1 et seq.—William James, Principles of Psychology, vol. ii, chap. xxii.—Cf. on the subject of the visual perception of extensity: Dunan, L'espace visuel et l'espace tactile (Revue philosophique, Feb. and Apr. 1888, Jan. 1889).
* ↑ Ward, Article Psychology in the Encycl. Britannica.
* ↑ W. James, Principles of Psychology, vol. ii, p. 134 et seq.—We may note in passing that we might, in strictness, attribute this opinion to Kant, since The Transcendental Æsthetic allows no difference between the data of the different senses as far as their extension in space is concerned. But it must not be forgotten that the point of view of the Critique is other than that of psychology, and that it is enough for its purpose that all our sensations should end by being localized in space when perception has reached its final form.