Now, here is the image which I call a material object; I have the representation of it. How comes it that it does not appear to be in itself that which it is for me? It is because, being bound up with all other images, it is continued in those which follow it, just as it prolonged those which pre ceded it. To transform its existence into represen tation, it would be enough to suppress what follows it, what precedes it, and also all that fills it, and to retain only its external crust, its superficial skin.
That which distinguishes it as a present image, as an objective reality, from a represented image is the necessity which obliges it to act through every one of its points upon all the points of all other images, to transmit the whole of what it receives, to oppose to every action an equal and contrary reaction, to be, in short, merely a road by which pass, in every direction, the modifications propagated through out the immensity of the universe. I should con vert it into representation if I could isolate it, especially if I could isolate its shell. Represen tation is there, but always virtual — being neutral ized, at the very moment when it might become actual, by the obligation to continue itself and to lose itself in something else. To obtain this con version from the virtual to the actual it would be necessary, not to throw more light on the object, but on the contrary to obscure some of its aspects, to diminish it by the greater part of itself, so that the remainder, instead of being encased in its sur roundings as a thing, should detach itself from them as a picture. Now if living beings are, within the uni verse, just ' centres of indetermination,' and if the degree of this indetermination is measured by the number and rank of their functions, we can con ceive that their mere presence is equivalent to the suppression of all those parts of objects in which their functions find no interest. They allow to pass through them, so to speak, those external in fluences which are indifferent to them; the others CHAP, i THE CHOICE OF IMAGES 2Q isolated, become ' perceptions ' by their very isolation. Everything thus happens for us as though we reflected back to surfaces the light which emanates from them, the light which, had it passed on unopposed, would never have been revealed. The images which surround us will appear to turn towards our body the side, emphasized by the light upon it, which interests our body. They will detach from themselves that which we have arrested on its way, that which we are capable of influencing. Indifferent to each other because of the radical mechanism which binds them to gether, they present each to the others all their sides at once: which means that they act and react mutually by all their elements, and that none of them perceives or is perceived consciously. Suppose, on the contrary, that they encounter some where a certain spontaneity of reaction: their action is so far diminished, and this diminution of their action is just the representation which we have of them. Our representation of things would thus arise from the fact that they are thrown back and reflected by our freedom.
When a ray of light passes from one medium into another, it usually traverses it with a change of direction. But the respective den sities of the two media may be such that, for a given angle of incidence, refraction is no longer possible. Then we have total reflexion. The luminous point gives rise to a virtual image which symbolizes, so to speak, the fact that the luminous 3O MATTER AND MEMORY CHAP, i rays cannot pursue their way. Perception is just a phenomenon of the same kind. That which is given is the totality of the images of the material world, with the totality of their internal elements. But if we suppose centres of real, that is to say of spontaneous, activity, the rays which reach it, and which interest that activity, instead of pass ing through those centres, will appear to be re flected and thus to indicate the outlines of the object which emits them. There is nothing positive here, nothing added to the image, nothing new. The objects merely abandon something of their real action in order to manifest their virtual action — that is to say, in the main, the eventual influence of the living being upon them. Per ception therefore resembles those phenomena of reflexion which result from an impeded refraction; it is like an effect of mirage.
This is as much as to say that there is for images merely a difference of degree, and not of kind, beso that tween being and being consciously pertion results ceived. The reality of matter consists omission oi in the totality of its elements and of that in the,.. r,., ~ totality of their actions oi every kind. Our rematter which..., has no presentation of matter is the measure interest for...,,..
our needs, of our possible action upon bodies: it results from the discarding of what has no interest for our needs, or more generally for our functions. In one sense we might say that the perception of any unconscious material point whatever, in its instantaneousness, is infinitely greater and more complete than ours, since this point gathers and transmits the influences of all the points of the material universe, whereas our consciousness only attains to certain parts and to certain aspects of those parts. Consciousness, — in regard to external perception, — lies in just this choice. But there is, in this necessary poverty of our conscious per ception, something that is positive, that foretells spirit: it is, in the etymological sense of the word, discernment.
The whole difficulty of the problem that occu pies us comes from the fact that we imagine perception to be a kind of photographic limited by view of things, taken from a fixed point indeterminate by that special apparatus which is called action the...
living being an organ of perception — a photograph which would then be developed in the brain-matter by some unknown chemical and psychical process of elaboration. But is it not obvious that the photograph, if photograph there be, is already taken, already developed in the very heart of things and at all the points of space? No metaphysics, no physics even, can escape this conclusion. Build up the universe with atoms: each of them is subject to the action, variable in quantity and quality according to the distance, exerted on it by all material atoms. Bring in Faraday's centres of force: the lines of force emitted in every direction from every centre bring to bear upon each the influences of the whole material world. Call up the Leibnizian monads: each is the mirror of the universe. All philosophers, then, agree on this point. Only if when we consider any other given place in the universe we can regard the action of all matter as passing through it without resistance and without loss, and the photograph of the whole as trans lucent: here there is wanting behind the plate the black screen on which the image could be shown. Our ' zones of indetermination ' play in some sort the part of the screen. They add nothing to what is there; they effect merely this: that the real action passes through, the virtual action remains.
This is no hypothesis. We content ourselves with formulating data with which no theory of perception can dispense. For no philosopher can begin the study of external perception with out assuming the possibility at least of a material world, that is to say, in the main, the virtual perception of all things. From this merely possible material mass he will then isolate the particular object which I call my body, and, in this body, centres of perception: he will show me the disturbance coming from a certain point in space, propagating itself along the nerves and reaching the centres. But here I am confronted by a transformation scene from fairyland. The material world which surrounds the body, the body which shelters the brain, the brain in which we distinguish centres, he abruptly dismisses; and, as by a magician's wand, he conjures up, as a thing entirely new the representation of what he began by postulating. This representation he drives out of space, so that it may have nothing in common with the matter from which he started. As for matter itself, he would fain go without it, but cannot, because its phenomena present relatively to each other an order so strict and so indifferent as to the point of origin chosen, that this regularity and this indifference really constitute an independent existence. So that he must resign himself to retaining at least the phantasm of matter. But then he manages to deprive it of all the qualities which give it life. In an amorphous space he carves out moving figures; or else (and it comes to nearly the same thing), he imagines relations of magnitude which adjust themselves one to another, mathematical functions which go on evolving and developing their own content: representation, laden with the spoils of matter, thenceforth displays itself freely in an unextended consciousness. — But it is not enough to cut out, it is necessary to sew the pieces together. You must now explain how those qualities which you have detached from their material support can be joined to it again. Each attribute which you take away from matter widens the interval between repre sentation and its object. If you make matter unextended, how will it acquire extension? If you reduce it to homogeneous movement, whence arises quality? Above all, how are we to imagine a relation between a thing and its image, between matter and thought, since each of these terms possesses, by definition, only that which is lack ing to the other? Thus difficulties spring up beneath our feet; and every effort that you make to dispose of one of them does but resolve it into many more. What then do we ask of you? Merely to give up your magician's wand, and to continue along the path on which you first set out. You showed us external images reaching the organs of sense, modifying the nerves, propa gating their influence in the brain. Well, follow the process to the end. The movement will pass through the cerebral substance (although not without having tarried there), and will then expand into voluntary action. There you have the whole mechanism of perception. As for perception itself, in so far as it is an image, you are not called upon to retrace its genesis, since you posited it to begin with, and since moreover no other course was open to you. In assuming the brain, in assuming the smallest portion of matter, did you not assume the totality of images? What you have to explain, then, is not how perception arises, but how it is limited, since it should be the image of the whole, and is in fact reduced to the image of that which interests you. But if it differs from the mere image, precisely in that its parts range themselves with reference to a variable centre, its limitation is easy to under stand: unlimited dc jure, it confines itself de facto CHAP. I REPRESENTATION AND ACTION 35 to indicating the degree of indetermination allowed to the acts of the special image which you call your body. And, inversely, it follows that the indetermination of the movements of your body, such as it results from the structure of the grey matter of the brain, gives the exact measure of the extent of your perception. It is no wonder, then, that everything happens as though your perception were a result of the internal motions of the brain, and issued in some sort from the cortical centres. It could not actually come from them, since the brain is an image like others, enveloped in the mass of other images, and it would be absurd that the container should issue from the content. But since the structure of the brain is like the detailed plan of the movements among which you have the choice, and since that part of the external images which appears to return upon itself in order to constitute perception includes precisely all the points of the universe which these movements could affect, conscious per ception and cerebral movement are in strict corre spondence. The reciprocal dependence of these two terms is therefore simply due to the fact that both are functions of a third, which is the indeter mination of the will.
Take, for example, a luminous point P, of which The image, the rays impinge on the different parts formed and a, b, c, of the retina. At this point P perceived in IT ••>, • f the object, science localizes vibrations of a cer tain, tain amplitude and duration. At the same point P consciousness perceives light. We propose to show, in the course of this study, that both are right; and that there is no essential difference between the light and the movements, provided we restore to movement the unity, indivisibility, and qualitative hetero geneity denied to it by abstract mechanics; provided also that we see in sensible qualities contractions effected by our memory. Science and consciousness would then coincide in the in stantaneous. For the moment all we need say, without examining too closely into the meaning of the words, is that the point P sends to the retina vibrations of light. What happens then? If the visual image of the point P were not already given, we should indeed have to seek the manner in which it had been engendered, and should soon be confronted by an insoluble problem. But, whatever we do, we cannot avoid assuming it to begin with: the sole question is, then, to know how and why this image is chosen to form part of my perception, while an infinite number of other images remain ex cluded from it. Now I see that the vibrations transmitted from the point P to the various parts of the retina are conducted to the sub-cortical and cortical optic centres, often to other centres as well, and that these centres sometimes transmit them to motor mechanisms, sometimes provision ally arrest them. The nervous elements concerned are, therefore, what give efficacy to the disturbance CHAP, i REPRESENTATION AND ACTION 37 received; they symbolize the indetermination of the will; on their soundness this indetermination depends; and consequently any injury to these elements, by diminishing our possible action, diminishes perception in the same degree. In other words, if there exist in the material world places where the vibrations received are not mechanically transmitted, if there are, as we said, zones of indetermination, these zones must occur along the path of what is termed the sensori-motor process; and hence all must happen as though the rays Pa, Pb, PC were perceived along this path and afterwards projected into P. Further, while the indetermination is something which escapes experiment and calculation, this is not the case with the nervous elements by which the impres sion is received and transmitted. These elements are the special concern of the physiologist and the psychologist; on them all the details of exter nal perception would seem to depend and by them they may be explained. So we may say, if we like, that the disturbance, after having travelled along these nervous elements, after having gained the centre, there changes into a conscious image which is subsequently exteriorized at the point P. But, when we so express ourselves, we merely bow to the exigencies of the scientific method; we in no way describe the real process. There is not, in fact, an unextended image which forms itself in consciousness and then projects itself into P.
The truth is that the point P, the rays which it emits, the retina and the nervous elements af fected, form a single whole; that the luminous point P is a part of this whole; and that it is really in P, and not elsewhere, that the image of P is formed and perceived.
When we represent things to ourselves in this manner, we do but return to the simple convictions of common sense. We all of us began by believ ing that we grasped the very object, that we per ceived it in itself and not in us. When philoso phers disdain an idea so simple and so close to reality, it is because the intra-cerebral process, — that diminutive part of perception, — appears to them the equivalent of the whole of percep tion. If we suppress the object perceived and keep the internal process, it seems to them that the image of the object remains. And their belief is easily explained: there are many conditions, such as hallucination and dreams, in which images arise that resemble external perception in all their details. As, in such cases, the object has disappeared while the brain persists, he holds that the cerebral phenomenon is sufficient for the production of the image. But it must not be forgotten that in all psychical states of this kind memory plays the chief part. Now, we shall try to show later that, when perception, 'as we understand it, is once admitted, memory must arise, and that this memory has not, any more than perception itself, a cerebral state as its true and complete condition. But, without as yet enter- CHAP, i REPRESENTATION AND ACTION 39 ing upon the examination of these two points, we will content ourselves with a very simple observa tion, which has indeed no novelty. In many people who are blind from birth the visual centres are intact; yet they live and die without having formed a single visual image. Such an image, therefore, cannot appear unless the external object has, once at least, played its part: it must, once at any rate, have been part and parcel with repre sentation. Now this is what we claim and for the moment all that we require, for we are dealing here with pure perception, and not with perception complicated by memory. Reject then the share of memory, consider perception in its unmixed state, and you will be forced to recognize that there is no image without an object. But, from the moment that you thus posit the intra-cerebral processes besides the external object which causes them, we can clearly see how the image of that object is given with it and in it: how the image should arise from the cerebral movement we shall never understand.
When a lesion of the nerves or of the centres interrupts the passage of the nerve vibration, perception is to that extent diminished.
But an injury.
to the brain Need we be surprised? The office of diminishes,...- perception by the nervous system is to utilize that lessening the.,...appeal to vibration, to convert it into practical deeds, really or virtually accomplished.
If, for one reason or another, the disturbance cannot pass along, it would be strange if the correspond- 4O MATTER AND MEMORY CHAP, i ing perception still took place, since this percep tion would then connect our body with points of space which no longer directly invite t to make a choice. Sever the optic nerve of an animal: the vibrations issuing from the luminous point can no longer be transmitted to the brain and thence to the motor nerves; the thread, of which the optic nerve is a part and which binds the external object to the motor mechanisms of the animal, is broken: visual perception has there fore become impotent, and this very impotence is unconsciousness. That matter should be per ceived without the help of a nervous system, and without organs of sense, is not theoretically inconceivable; but it is practically impossible, because such perception would be of no use. It would suit a phantom, not a living, and therefore acting, being. We are too much inclined to regard the living body as a world within a world, the ner vous system as a separate being, of which the func tion is, first, to elaborate perceptions, and then to create movements. The truth is that my nervous system, interposed between the objects which affect my body and those which I can influence, is a mere conductor, transmitting, sending back, or inhibiting movement. This conductor - is composed of an enormous number of threads which stretch from the periphery to the centre, and from the centre to the periphery. As many threads as pass from the periphery to the centre, so many points of space are there able CHAP, i REPRESENTATION AND ACTION 41 to make an appeal to my will and to put, so to speak, an elementary question to my motor activity. Every such question is what is termed a perception. Thus perception is diminished by one of its elements each time one of the threads termed sensory is cut, because some part of the external object then becomes unable to appeal to activity; and it is also diminished whenever a stable habit has been formed, because this time the ready-made response renders the question unnecessary. What disappears in either case is the apparent reflexion of the stimulus upon itself, the return of the light on the image whence it comes; or rather that dissociation, that discern ment, whereby the perception is disengaged from the image. We may therefore say that while the detail of perception is moulded exactly upon that of the nerves termed sensory, perception as a whole has its true and final explanation in the tendency of the body to movement.
The cause of the general illusion on this point lies in the apparent indifference of our movements to the stimulation which excites them. It seems that the movement of my body in order to reach and to modify an object is the same, whether I have been told of its existence by the ear or whether it has been revealed to me by sight or touch. My motor activity thus appears as a separate entity, a sort of reservoir whence movements issue at will, always the same for the same action, whatever the kind of image which has called it into being.
42 MATTER AND MEMORY CHAF. I But the truth is that the character of movements which are externally identical is internally differ ent, according as they respond to a visual, an au ditory or a tactile impression. Suppose I perceive a multitude of objects in space; each of them, inasmuch as it is a visual form, solicits my acti vity. Now I suddenly lose my sight. No doubt I still have at my disposal the same quantity and the same quality of movements in space; but these movements can no longer be co-ordinated to visual impressions; they must in future follow tactile impressions, for example, and a new arrangement will take place in the brain. The protoplasmic expansions of the motor nervous elements in the cortex will be in relation, now, with a much smaller number of the nervous elements termed sensory. My activity is then really diminished, in the sense that although I can produce the same movements, the occasion comes more rarely from the external objects. Con sequently, the sudden interruption of optical continuity has brought with it, as its essential and profound effect, the suppression of a large part of the queries or demands addressed to my activity. Now such a query or demand is, as we have seen, a perception. Here we put our finger -on the mistake of those who maintain that percep tion springs from the sensory vibration properly so called, and not from a sort of question ad dressed to motor activity. They sever this motor activity from the perceptive process; and, as REPRESENTATION AND ACTION 43 it appears to survive the loss of perception, they conclude that perception is localized in the nervous elements termed sensory. But the truth is that perception is no more in the sensory centres than in the motor centres; it measures the complexity of their relations, and is, in fact, where it appears to be.
Psychologists who have studied infancy are well aware that our representation is at first impersonal.
Only little by little, and as a result of In perception •» J fromlne1 experience, does it adopt our body as a periphery— centre and become our representation.
the aggregate * oi images, to j^g mechanism of this process is, morethe centre — • * mS Sversa over> easv to understand. As my body moves in space, all the other images vary, while that image, my body, remains invariable. I must therefore make it a centre, to which I refer all the other images. My belief in an external world does not come, cannot come, from the fact that I project outside myself sensations that are unextended: how could these sensations ever acquire ex tension, and whence should I get the notion of ex teriority? But if we allow that, as experience testi fies, the aggregate of images is given to begin with, I can see clearly how my body comes to occupy, within this aggregate, a privileged position. And I understand also whence arises the notion of interiority and exteriority, which is, to begin with, merely the distinction between my body and other bodies. For if you start from my body, as is usually done, you will never make me understand how impressions received on the surface of my body, impressions which concern that body alone, are able to become for me independent objects and form an external world. But if, on the contrary, all images are posited at the outset, my body will necessarily end by standing out in the midst of them as a distinct thing, since they change unceas ingly, and it does not vary. The distinction between the inside and the outside will then be only a dis tinction between the part and the whole. There is, first of all, the aggregate of images; and then, in this aggregate, there are ' centres of action,' from which the interesting images appear to be reflected: thus perceptions are born and actions made ready. My body is that which stands out as the centre of these perceptions; my personality is the being to which these actions must be referred. The whole subject becomes clear if we travel thus from the peri phery to the centre, as the child does, and as we ourselves are invited to do by immediate experience and by common sense. On the contrary everything becomes obscure, and problems are multiplied on all sides, if we attempt, with the theorists, to travel from the centre to the periphery. — Whence arises, then, this idea of an external world constructed arti ficially, piece by piece, out of unextended sensa tions, though we can neither understand how they come to form an extended surface, nor how they are subsequently projected outside our body?
Why insist, in spite of appearances, that I should go from my conscious self to my body, then CHAP, i THE IMAGE AND REALITY 45 from my body to other bodies, whereas in fact I place myself at once in the material world in general, and then gradually cut out within it the centre of action which I shall come to call my body and to distinguish from all others? — There are so many illusions gathered round this belief in the originally unextended character of our external perception; there are, in the idea that we project outside our selves states which are purely internal, so many misconceptions, so many lame answers to badly stated questions, that we cannot hope to throw light on the whole subject at once. We believe that light will increase, as we show more clearly, behind these illusions, the metaphysical error which confounds the unbroken extensity with homo geneous space, and the psychological error which confounds ' pure perception ' with memory. But these illusions are, nevertheless, connected with real facts, which we may here indicate in order to correct their interpretation.
The first of these facts is that our senses require education. Neither sight nor touch is able at objection the outset to localize impressions. A SKo-cSS series °f comparisons and inductions is ofdtheasenses necessary, whereby we gradually coi^?o!als™han" ordinate one impression with another, education. Hence philosophers may jump to the belief that sensations are in their essence inextensive, and that they constitute extensity by their juxtaposition. But is it not clear that, upon the hypothesis just advanced, our senses are equally in need of education, — not of course in order to accom modate themselves to things, but to accommodate themselves to each other? Here, in the midst of all the images, there is a certain image which I term my body, and of which the virtual action reveals itself by an apparent reflexion of the surround ing images upon themselves. Suppose there are so many kinds of possible action for my body: there must be an equal number of systems of reflexion for other bodies; and each of these systems will be just what is perceived by one of my senses. My body, then, acts like an image which reflects others, and which, in so doing, analyses them along lines corresponding to the different actions which it can exercise upon them.
And, consequently, each of the qualities perceived in the same object by my different senses symbolizes a particular direction of my activity, a par ticular need. Now, will all these perceptions of a body by my different senses give me, when united, the complete image of that body? Cer tainly not, because they have been gathered from a larger whole. To perceive all the influences from all the points of all bodies would be to de scend to the condition of a material object. Con scious perception signifies choice, and consciousness mainly consists in this practical discernment. The diverse perceptions of the same object, given by my different senses, will not, then, when put to gether, reconstruct the complete image of the