3. Materialism and Parallelism Materialism is a very ancient doctrine. It is even the most ancient of all, which simply proves that amongst the different explanations, given of our double physical mental nature, this doctrine is the easiest to understand. The origin of materialism is to be found in the beliefs of savage tribes, and is again found very clearly defined in the philosophy of those ancient Greeks who philosophized before Plato and Aristotle. A still stranger fact is that the thoughts of a great number of the Fathers of the Church inclined toward the philosophy of matter. Then, in the course of its evolution, there occurred a moment of eclipse, and materialism ceased to attract attention till the contemporary period, in which we assist at its rebirth. Nowadays it constitutes a powerful doctrine, the more so that it has surreptitiously crept into the thoughts of many learned men without their being clearly conscious of it. There are many physicists and physiologists who think and speak as materialists, though they have made up their minds to remain on the battleground of observed facts and have a holy horror of metaphysics. In a certain sense it may be said that materialism is the metaphysics of those who refuse to be metaphysicians. It is very evident that in the course of its long history materialism has often changed its skin. Like all knowledge it has been subject to the law of progress, and certainly it would not have been of a nature to satisfy the intellectual wants of contemporary scholars had it not stripped itself of the rude form under which it first manifested itself in the mind of primitive man. Yet what has enabled the doctrine to keep its unity through all its changes is that it manifests a deeply human tendency to cling by preference to everything visible and tangible. Whatever strikes the eyes, or can be felt by the hand, seems to us in the highest degree endowed with reality or existence. It is only much later, after an effort of refined thought, that we come to recognize an existence in everything that can be perceived in any way whatever, even in an idea. It is still later that we understand that existence is not only that which is perceived, but also that which is linked logically with the rest of our knowledge. A good deal of progress has been necessary to reach this point. As I have not the slightest intention of giving even an abridged history of materialism, let us come at once to the present day, and endeavor to say in what consists the scientific form this doctrine has assumed. Its fundamental basis has not changed. It still rests on our tendency to give chief importance to what can be seen and touched, and it is an effective hegemony of three of our senses, the visual, the tactile, and the muscular. The extraordinary development of the physical sciences has no doubt given an enormous encouragement to materialism, and it may be said that in the philosophy of nature it occupies a principal place, and that it is there in its own domain and unassailable. It has become the expression of the idea that everything can be explained scientifically. Everything susceptible of being measured is a material phenomenon. It is the representation of the material explanation pushed to its last limits, and all experiments, all calculations, all inductions resting on the grand principle of the conservation of matter and energy plead in its favor. We will examine with some precision how far such a doctrine solves the problem of the existence of the intellectual functions. The doctrine has understood this connection as being purely material, and has sought its image in other phenomena which are entirely so. Thus it has borrowed from physiology the principle of its explanation. It has transported into the domain of thought the idea of function, and it has supposed that the soul is to the body in the relation of function to organ. Intelligence would thus be a cerebral function. To explain intelligence materialist link it with matter, turn it into a property of matter, and compare it to a movement of matter, and sometimes even to a secretion. So Karl Vogt, the illustrious Genevan naturalist, one day declared to the great scandal of everyone that the brain secretes the thought as the kidney does urine. This bold comparison seems shocking, purile, and false, for a secretion is a material thing while thought is not. Karl Vogt also employed another comparison. The brain produces the thought as the muscle produces movement, and it at once seems less offensive to compare the thought to a movement than to compare it to a liquid secretion. At the present day an illustration still more vague would be used, such as that of a transformation of energy, chemical energy disengaged by the nerve centers would be thus looked upon as transformed into psychical energy. However it matters little what metaphors are applied to for help in explaining the passage from the physical to the mental. What characterizes materialist philosophy is its belief in the possibility of such a passage, and it's considering it as the genesis of thought. One calls materialist, says Renaud Vieille, with great exactness, every philosophy which defines thought as the product of a compound whose elements do not imply thought. A sweeping formula which allows us to foresee all the future avatars of the materialist doctrine and to class them beforehand in the same category. The criticisms which have been directed against materialism are all, or nearly all, variations of the principle of heterogeneity. We will not dwell long on this, but simply recollect that, according to this principle, it is impossible to attribute to the brain the capacity of generating consciousness. Physical force can indeed generate physical force under the same or a different form, and it thus produces all the effects which are determined by the laws of nature. But it is impossible to comprehend how physical force can enrich itself at a given moment by a conscious force. Physical force is reduced to movements of bodies and to displacements of atoms. How could a change of position in any inert objects give rise to a judgment, a reasoning, or any phenomenon of the consciousness? It is further said, this idea of function which materialists here introduce to render more comprehensible the passage from a material body to a spiritual action, contains only an empty explanation, for the function is not essentially distinct by its nature from the organ, it is simply the organ in activity. It adds to the organ taken in the state of repose, but one change, v's activity, that is to say movement, and consequently the function of an organ is material by the same right as the organ. When a muscle contracts, this contraction, which is the proper function of the muscular fiber, consists in a condensation of the muscular protoplasm, and this condensation is a material fact. When a gland enters into activity, a certain quantity of liquid flows into the channels of the gland, and this liquid is caused by a physical and chemical modification of the cellular protoplasm. It is a melting or a liquefaction which likewise is material. The function of the nerve cell is to produce movement, or to preserve it, or to direct it. It is material, like the cells. There is therefore nothing in all those functional phenomena which might lead us to understand how a material cause should be capable of engendering a conscious effect. It seems that all materialists have acknowledged that here is the vulnerable point in their theory, for it is the principle of heterogeneity which they have especially combated. But their defense is wanting in frankness and principally consists in subterfuges. In brief, it affirms that we are surrounded with mystery, that we are not sufficiently learned to have the right to impose limits to the power of matter, and to say to it, thou shalt not produce this phenomenon. A materialist theologian declares that he sees no impossibility in Stone's thinking in arguing if God in his infinite power has decided to unite thought with brute matter. This argument is not really serious. It demands the intervention of so powerful a deuce ex machina that it can be applied equally to all problems. To solve all is to solve none. Modern materialists rightly do not bring God into the question. Their mode of argument takes another form, but it remains to be seen if, at bottom, it is not the same as the other. It simply consists in affirming that up till now we know certain properties of matter only, but that science every day discovers new ones. That matter is a reservoir of unknown forces, and that it is not impossible that the origin of psychical forces may yet be discovered in matter. This idea is clearly hinted at by Litra. The physicist Tyndall gave it a definite formula when he uttered at the Belfast Congress this phrase so often quoted. If I look back on the limits of experimental science, I can discern in the bosom of that matter, which in our ignorance while at the same time professing our respect for its creator, we have till now treated with opprobrium, the promise and the power of all forms and qualities of life. The opponents of the doctrine have not ceased to answer that the matter of tomorrow, like the matter of today, can generate none but material effects, and that a difficulty is not solved by putting off a solution to some indefinite day in our scientific evolution. And it certainly seems that the counterstroke is decisive if we admit the principle of heterogeneity with its natural consequence. We will now criticize the above doctrine by making use of the ideas I have above enunciated. The criticism we have to apply to materialism is not the same as that just summarized. The axis of the discussion changes its position. In the first place, I reproach materialism with presenting itself as a theory of the generation of the consciousness by the object. We have already reproached idealism with putting itself forward as a theory of the generation of the object by the consciousness. The error of the two systems is produced in a converse direction but is of the same gravity. The consciousness and its object, we say yet again, constitute the widest division it is possible to affect in the domain of cognition. It is quite as illegitimate to reduce the first term to the second as to reduce the second to the first. To reduce one to the other by way of affiliation or otherwise, there must first be discovered then an identity of nature which does not exist. In the second place, when one examines closely the explanation materialism has imagined in order to derive thought from an action of matter, it is seen that this representation is rendered completely impossible by all we know of the nature of thought. For the materialist to suppose for one moment that thought is a cerebral function, he must evidently make an illusion for himself as to what thought is, and must juggle with concepts. Perhaps, could we penetrate into his own inmost thought, we should discover that at the moment he supposes a mere cell can manufacture the phenomena of consciousness. Some vague image suggests itself to him whereby he identifies these phenomena with a light and subtle principle escaping from the nerve cell, something which resembles an electric effluve, or a will of the wisp or the flame from a punch bowl. I cannot of course tell whether my supposition is correct, but what I assert with the calmness of perfect certitude is that the materialist has not taken the pains to analyze attentively what he calls the phenomenon of consciousness. Had he made this analysis and kept the elements in his mind, he would have seen that it is almost impossible to hook in any way a phenomenon of consciousness onto a material molecule. In fact also, to take this into account, we will not remain within the vagueness of the concept, but will take a particular example to argue upon these that of an external perception. I open my window on a fine day, and I see before me a sunny plain, with, as far as the eye can reach, houses amongst the trees, and again more houses, the most distance of which are outlined against my far off horizon. This is my mental phenomenon. And while I am at my window, my eyes fixed on the view, the anatomist declares that, starting from my retina, molecular vibrations travel along the optic nerve, cross each other at the chiasma, enter into the fascia, pass through the internal capsule, and reach the hemispheres, or rather the occipital regions of the brain, where, for the moment, we agree to localize the center of projection of the visual sensations. This is my physical phenomenon. It now becomes the question of passing from this physical phenomena to the mental one. And here we are stopped by a really formidable difficulty. My mental phenomenon is not entirely mental, as it is usually supposed from the deceitful brevity of the phrase. It is in great part physical, for it can be decomposed into two elements, a consciousness and its object. And this object of the consciousness, this group of little houses I see in the plain, belongs to sensation. That is to say, to something physical, or, in other words, to matter. Let us examine in its turn the physical process which is supposed to be discovered in my nervous centers while I am in course of contemplating the landscape. This pretended physical process itself, quite as much as my conscious perception of the landscape, is a physical, psychical phenomenon, for my cerebral movements are perceived, hypothetically at least, by an observer. This is a perception. Consequently, it can be decomposed into two things, a consciousness and its object. As a further consequence, when we wish, by a metaphysical effort, to attach the consciousness to a material state of the brain and to establish a link between the two events, it will be found that we wrongly hook one physical mental phenomenon onto another. But evidently, this objection is not a refutation. We may, if we choose, suppose that the so-called cerebral process is capable of subsisting at moments when no one perceives it, and that it exists of itself, is sufficient for itself, and is entirely physical. But can we subject the mental process of perception to the same purification? Can we separate these two elements, the consciousness and its object, retain the element consciousness, and reject the element object, which is physical, thus constituting a phenomenon entirely mental, which might then be possibly placed beside the entirely physical phenomenon so as to study their relation to each other? This is quite impossible, and the impossibility is double, for it exists the facto and de jure. De jure, because we have already established that a consciousness empty and without object cannot be conceived. The facto, because the existence of the object that consciousness carries with it, is very embarrassing for the materialist, for this object is material and as real and material as the fibers and cells of the brain. It might indeed be supposed that by transformation or otherwise there goes forth from the cerebral convolution a purely psychical phenomenon resembling a wave. But how can we conceive the transformation of this convolution into a semi-material phenomenon? How can we comprehend that there should issue from this convolution the material object of a perception, for example, a plane dotted with houses? An English histologist remarked one day with some eloquence how little the most minute study of the brain aided us to understand thought. He was thus answering Auguste Comte, who in a moment of aberration claimed that psychology, in order to become a science, ought to reject the testimony of the consciousness and to use exclusively as its means of study the histology of the nerve centers and the measurement of the cranium. Our histologist, who had passed part of his life examining, under the microscope, fragments of cerebral matter in following the forms of the cells, the course of the fibers, and the grouping and distribution of the fascia, made the following remark. It is the fact that the study, however patient, minute, and thorough it might be, of this nerve skein, can never enable us to know what a state of consciousness is, if we do not know it otherwise, for never across the field of the microscope is there seen to pass a memory, an emotion, or an act of volition. And he added, he who confines himself to peering into these material structures remains as ignorant of the phenomena of the mind as the London cab men who, for ever traveling through the streets of the great city, is ignorant of what is said and what is going on in the interior of the houses. This picturesque comparison, the truth of which has never been questioned, is based on this supposition, that the psychical act is entirely immaterial and invisible, and therefore escapes the piercing eye of the microscope. But a deeper analysis of the mind shows how little exact is this assertion. From the moment each psychical act implies a material object, we can ask ourselves two things. One, why is it that the anatomist does not discover these material objects in the interior of the brain? We ought to see them, for they are material and therefore visible. We ought to see them with their aspect and color, or be able to explain why they are not seen. In general, all that is described to us in the brain is the molecular vibrations, but we are not conscious of them. Where then is that of which we are conscious? Two, it should next be explained to us by what elaboration, transportation, or metamorphosis a molecular disturbance, which is material, can transform itself into the objects which are equally material. This is the criticism we have to address to materialism, until proof to the contrary, I hold it to be irrefutable. Parallelism. For this exposition to follow the logical order of ideas, the discussion on materialism should be immediately succeeded by that on parallelism. These two doctrines are near akin. They resemble each other as the second edition of a book, revised and corrected, resembles the first. Parallelism is the materialist doctrine of those forewarned folk who have perceived the errors committed and endeavored to avoid them, while cherishing all that can be saved of the condemned doctrine. That which philosophers criticized in materialism was the misunderstanding of the principle of heterogeneity. The parallelists have seen this mistake, and have taken steps to respect this principle. We shall see in what way. They are especially prudent, and they excel in avoiding being compromised. They put forth their hypothesis as a provisional one, and they vaunt its convenience. It is, say they, a practical method of avoiding many difficulties. It becomes for philosophers an equivalent of that phrase which so many timorous ministers repeat. Above all, no scrapes. Let us study the exact point on which parallelism has amended materialism. We have seen that every materialist doctrine is the expression of this idea, that physical phenomena are the only ones that are determined, measurable, explicable, and scientific. This idea does wonders in the natural sciences, but is at fault when, from the physical, we pass into the moral world, and we have seen how the materialistic doctrine fails when it endeavors to attach the physical to the mental. There are then two great difficulties which the materialistic explanation finds before it. One is a difficulty of mechanism and the other of genesis. By connecting the mind with the brain, like a function to its organ, this doctrine seeks to solve these two problems, and with what little success we have seen. Parallelism has tried to avoid these two problems. Not only does it not solve them, but it arranges so as not to propound them. The expedient adopted consists in avoiding the meeting of the physical and the mental. Instead of placing them end to end and welding them one to the other, they are placed in parallel fashion side by side. To explain their correlation, which so many observations vaguely demonstrate, the following hypothesis is advanced. Physical and psychical life form two parallel currents, which never mingle their waters. To every state of definite consciousness, there corresponds the counterpart of an equally definite state of the nerve centers. The fact of consciousness has its antecedents and its consequences in the consciousness, and the physical fact equally takes its place in a chain of physical facts. The two series are thus evolved, and correspond strictly to each other according to a necessary law, so that the scholar who was perfectly instructed and to whom one of these states was presented could describe its fellow, but never does any of the terms of one series influence the terms of the other. Observation and the testimony of the consciousness seem to attest this dual progress, but they are, according to the parallelist hypothesis, illusions. When I move my arm by a voluntary act, it is not my will, qua act of consciousness, which determines the movement of the arm, for this is a material fact. The movement is produced by the coming into play of groups of muscles. Each muscle, composed of a semi-fluid substance, being excited, contracts in the direction of its greatest length. The excitant of the muscles is also a material fact, a material influx which starts from the motor cells of the encephalon, and of which we know the course down through the pyramidal fascium, the anterior roots of the spinal cord, and the nerves of the periphery to its termination in the motor plates of the muscles. It is this excitement which is the physical, direct, and veritable cause of voluntary movements, and it is the same which all acts and signs, all expressions of our conscious states, the trembling of fear, the redness of anger, the movements of walking, down to the words we utter, all these are physical effects, produced by physical processes, which act physically, and of which the mental counterpart has in itself no effective action. Let it be understood that I am here pointing out one of the forms, and that the most usual, of the parallelist theory. Each author varies it according to his fancy, some widen the correspondence between the physical and the moral, others prefer to narrow it. At one time a vague relation is supposed, which is only true on a large scale, and is a union rather than an equivalence. At another, it is an exact counterpart, a complete duplicate in which the smallest physical event corresponds to a mental one. In one of the forms of this theory that has been recently invented, parallelists have gone so far as to assert that there exists no real cohesion in the mental chain, and that no mental phenomenon can have the property of provoking another mental phenomenon by an act of true causality. It is within the nervous tissue, they say, that the nexus of psychic states should be enclosed. These should succeed in time without being directly connected with one another. They should succeed because the physical basis of them is excited in succession. Some of them would be like an air on the piano. The notes follow each other, and arrange themselves into melodies, not by any affinity proper to themselves, but because the keys of the instrument are struck in the required order. I said a little while ago that parallelism was a perfected materialism. The reason of this will be understood. It is a doctrine which preserves the determinism of physical facts while avoiding the compromising of itself in the difficult explanation of the connection between the soul and the body. It remains scientific without raising a metaphysical heresy. Bain is one of those who have most clearly expressed not only the advantages, but also the aspirations of this theory. We have every reason for believing, he says, that there is in company with all our mental processes an unbroken material succession. From the ingress of a sensation to the outgoing responses in action, the mental succession is not for an instant the severed from a physical succession. A new prospect bursts upon the view there is mental result of sensation, emotion, thought, terminating an outward displays of speech or gesture. Parallel to this mental series is the physical series of facts, the successive agitation of the physical organs, called the eye, the retina, the optic nerve, optic centers, cerebral hemispheres, outgoing nerves, muscles, etc. While we go the round of the mental circle of sensation, emotion, and thought, there is an unbroken physical circle of effects. It would be incompatible with everything we know of the cerebral action to suppose that the physical chain ends abruptly in a physical void, accompanied by an immaterial substance. Which immaterial substance, after working alone, imparts its results to the outer edge of the physical break and determines the active response. Two shores of the material was an intervening ocean of the immaterial. There is, in fact, no rupture of nervous continuity. The only tenable supposition is that mental and physical proceed together as undivided twins. On reading this passage it is easy to see the idea which forms the basis of the doctrine. It is, as I have already said, the fetishism of mechanics. Parallelism takes its inspiration from this, quite as directly as does materialism, but with more skill, in as much as it avoids the most dangerous question, that of the interaction of physics and morals, and replaces it by an hypothesis much resembling Leibniz's hypothesis of the pre-established harmony. On the other hand, a second merit of this prudent doctrine is the avoiding the question of Genesis. It does not seek for the origin of thought, but places this last in a relation of parallelism with the manifestations of matter, and in the same way that parallel lines prolonged at infinitum never meet. So the partisans of this doctrine announce their resolution not to inquire how the actual state of things has been formed, nor how it will end if, for example, one of the terms should disappear by the death of the bodily organism. Notwithstanding so many precautions, criticisms have not been wanting. Only they would seem not to have touched the weak part of the doctrine, and not to be decisive. We will only run through them briefly. It has been said there is no logical necessity, which forces us to refuse to the consciousness the privilege of acting in complete independence of the nervous mechanism. It has also been said it is by no means certain that any nervous mechanism can be invented which imitates and, if need were, could replace an intellectual act. For instance, what association of nerve cells, what molecular action, can imitate an act of comparison which enables us to see a resemblance between two objects. Let it be supposed, for example, that the resemblance of two impressions come from a partial identity, and that the latter has for material support an identity in the sea or the form of the corresponding nervous influx. But what is identity? How can it be conceived without supposing resemblance of which it is but a form? How, then, can the one be explained by the other? Thus, for instance, at the bottom of all our intellectual acts, there is a certain degree of belief. Can any material combination be found which corresponds thereto? There is one last objection, the most serious of all. Parallelism by establishing a fixed and invariable relation between the physical and the moral ends by denying the role of this last, since the physical mechanism is sufficient to draw to itself all the effects which general belief attributes to the moral. The parallelists on this point go very much further than the materialists. The latter at least concede that the consciousness is of some use, since they compared it to a function or a secretion, and, after all, a secretion is a useful liquid. The parallelists are so strongly convinced that mechanism is alone efficacious that they come to deny any role to thought. The consciousness for them has no purpose, yet it keeps company with its object. The metaphors which serve to define it, part of which have been imagined by Huxley, are all of a passive nature. Such is the light or the whistling noise which accompanies the working of an engine but does not act on its machinery, or the shadow which dogs the steps of the traveler, or a phosphorescence lighting up the traces of the movement of the brain. It has also been said that the consciousness is a useless luxury. Some have even gone further, and the fine and significant name of epiphenomenon that has been given to thought well translates that conception, according to which semi-realities may exist in nature. All these objections certainly carry great weight, but they are not capable of killing the doctrine, they only scorch it. I think there is a radical vice in parallelism, which till now has not been sufficiently indicated, and I ask what can really remain of the whole edifice when this vice has been once exposed. Parallelism implies a false idea which we have already come across when discussing materialism. It is the idea that a phenomenon of consciousness constitutes one complete whole. The error proceeds from the use of concepts which cause the reality to be lost sight of. The reality shows that every phenomenon of consciousness consists in a mode of activity, an aggregate of faculties which require an object to fasten on to and so realize themselves, and that this object is furnished by matter. What we always know in intuition is the union, the incarnation of consciousness, matter. Our thoughts, our memories, our reasonings have as objects, sensations, images, that is to say things which strictly speaking are as material as our own brains. It is therefore rather childish to put all these workings of the spirit on another plane and in another world than the workings of the brain since they are in great part of the same nature as the last named and they contain so many material elements. Now if we re-establish facts as they are, if we admit a parallelism between psychical phenomena on the one hand and phenomena at once physical and psychical on the other, the parallelist hypothesis loses every sort of meaning. It ceases to present to us the image of two phenomena of an absolutely different order which are found coupled together like the two faces of a unity, the front and back of a page, the right and wrong side of a stuff. If there is anything material in the psychical part, the opposition of nature no longer exist between the two terms, they become identical. Very often certain parallelists, after thinking they have discovered the duality of nature, endeavor to bring it back to unity by supposing that the two faces of reality are as two effects of one unique reality, inaccessible to our senses and underlying appearances. Why go so far afield to seek unity? It is trouble in vain, for it is to be found in the phenomenon itself. The objection taken above to parallelism and materialism is personal to myself, because I have put it forward as a consequence of my analysis of the respective shares of thought and matter in every act of cognition. This is not so. I am here in harmony with other philosophers who arrived at the same conclusions long before me, and it may be useful to quote them. We will begin with the Prince of Idealists, Berkeley. Everything you know or conceive other than spirits, says Phelonis de Hylis, is but your ideas. So then when you say that all ideas are occasioned by impressions made in the brain, either you conceive this brain or you do not. If you conceive it, you are in that case talking of ideas imprinted in an idea which is the cause of this very idea, which is absurd. If you do not conceive it, you are talking unintelligibly. You are not forming a reasonable hypothesis. How can it be reasonable? He goes on to say. To think that the brain, which is a sensible thing, that is which can be apprehended by the senses, an idea consequently which only exists in the mind, is the cause of our other ideas. Note. I borrow this quotation from Renovier, the Personalism, page 263. And note. Thus in the reasoning of Berkeley, the function of the brain cannot explain the production of ideas, because the brain itself is an idea, and an idea cannot be the cause of all our other ideas. Mr. Bergson's argument is quite similar, although he takes a very different standpoint from that of idealism. He takes the word image in the vagus conceivable sense. To explain the meaning of this word, he simply says, images which are perceived when I open my senses and unperceived when I close them. He also remarks that the external objects are images, and that the brain and its molecular disturbances are likewise images. And he adds, For this image which I call cerebral disturbance to generate the external images, it would have to contain them in one way or another, and the representation of the whole material universe would have to be implicated in that of this molecular movement.  Note. Matière Memoir, page 3. The author has returned to this point more at length in a communication to the Congrès de Philosophie de Genève in 1904. Si, revue de metaphysique et de morale, novembre 1904, communication from H. Bergson, entitled L'Aperologisme, psychophysiologique. Here is a passage from this article which expresses the same idea. To say that the image of the surrounding world issues from this image, from the cerebral movement, or that it expresses itself by this image, or that it arises as soon as this image is suggested, or that one gives it to oneself by giving oneself this image would be to contradict oneself. Since these two images, the outer world and the intra-cerebral movement, have been supposed to be of the same nature, and the second image is, by the hypothesis, an infinitesimal part of the field of representation, while the first fills a whole of it. End note. It will be seen that this reasoning is the same as Berkeley's, though the two authors are reasoning on objects that are different. According to Berkeley, the brain and the states of conscience are psychical states. According to Bergson, the definition of the nature of these two objects, designated by the term image, is more comprehensive. But the essential of his argument is independent of this definition. It is enough that the two terms should be of similar nature for one to be unable to generate the other. My own argument in its turn comes rather near the preceding ones. For the idea of Berkeley and the image of Bergson, I substitute the term matter. I say that the brain is matter, and that the perception of any object is perception of matter, and I think it is not easy to explain how from this brain can issue this perception, since that would be to admit that from one matter may come forth another matter. There is certainly here a great difficulty. Mr. Bergson has thought to overcome it by attacking it in the following way. He has the very ingenious idea of changing the position of the representation in relation to the cerebral movement. The materialist places the representation after this movement and derives it from the movement. The parallelist places it by the side of the movement and in equivalence to it. Mr. Bergson places it before the movement and supposes it to play with regard to it the part of exciting cause, or simply that of initiator. This cerebral movement becomes an effect of the representation and a motor effect. Consequently, the nervous system passes into the state of motor organ. The sensory nerves are not, as supposed, true sensory nerves, but they are the commencements of motor nerves, the aim of which is to lead the motor excitements to the centers which play the part of commutators and direct the current, sometimes by one set of nerves, sometimes by others. The nervous system is like a tool held in the hand. It is a vehicle for action, we are told, and not a substratum for cognition. I cannot here say with what ingenuity, with what powerful logic, and with what close continuity of ideas Mr. Bergson develops his system, nor with what address he braves its difficulties. His mind is remarkable alike for its power of systematization and its suppleness of adaption. Before commencing to criticize him, I am anxious to say how much I admire him, how much I agree with him throughout the critical part of his work, and how much I owe to the perusal of his book Matière Memoir. Though I was led into metaphysics by private needs, though some of the ideas I have set forth above were conceptions of my own, for example, the criticism of the mechanical theory of matter, and the definition of sensation. Before I had read Mr. Bergson's book, it cannot be denied that its perusal has so strongly modified my ideas that a great part of these are due to him without my feeling capable of exactly discerning which. For ideas have a much more impersonal character than observations and experiments. It would therefore have been ungrateful to criticize him before having rendered him this tribute. There are, in Mr. Bergson's theory, a few assertions which surprise us a little, like everything which runs counter to old habits. It has always been supposed that our body is the receptacle of our psychological phenomenon. We store our reminiscences in our nerve centers. We put the state of our emotions in the perturbations of certain apparatus. We find the physical basis of our efforts of will and of attention in the sensations of muscular tension born in our limbs or trunk. Directly we believe that the nervous system is no longer the depository of these states. We must change their domicile and where are they to be placed. Here the theory becomes obscure and vague and custom renders it difficult to understand the situation of the mind outside the body. Mr. Bergson places memory in planes of consciousness far removed from action, and perception he places in the very object we perceive. If I look at my bookcase, my thought is in my books. If I look at the sky, my thought is in a star. Note. Métière et Memoir, page 31. End note. It is very difficult to criticize ideas such as these because one is never certain that one understands them. I will therefore not linger over them, notwithstanding the mistrust which they inspire in me. But what seems to me to require proof is the function Mr. Bergson is led to attribute to the sensory nerves. To his mind it is not exact to say that the excitement of a sensory nerve excites sensation. This would be a wrong description for according to him every nerve, even a sensory one, serves as a motor. It conducts the disturbance which passing through the central commutator flows finally into the muscles. But then, whence comes it that I think I feel a sensation when my sensory nerve is touched? Whence comes it that a pressure on the epitochlear nerve gives me a tingling in the hand? Whence comes it that a blow in the eyeball gives me a fleeting impression of light? One must read the page where Mr. Bergson struggles against what seems to me the evidence of the facts. If for one reason or another, he says, the excitement no longer passes, it would be strange if the corresponding perception took place, since this perception would then put our body in relation with points of space which would no longer invite it to make a choice. Divide the optic nerve of any animal. The disturbance starting from the luminous point is no longer transmitted to the brain and thence to the motor nerves. The thread which connected the external object to the motor mechanism of the animal by enveloping the optic nerve is severed. The visual perception has therefore become powerless, and in this powerlessness consists on consciousness. This argument is more clever than convincing. It is not convincing because it consists in exaggerating beyond all reason a very real fact. That of the relation which can be discovered between our sensations and our movements. We believe with Mr. Bergson that it is absolutely correct to see in action the end and the raison d'etre of our intelligence and our sensibility. But does it follow that every degree, every shade, every detail of sensation, even the most insignificant, has any importance for the action? The variations of sensibility are much more numerous than those of movements and of adaption. Very probably, as seen in an attentive study of infancy, sensibility precedes the power of motion in its differentiations. A child shows an extraordinary acuteness of perception at an age when its hand is still very clumsy. The correlation then is not absolute, and then even if it were so, it would not follow that the suppression of any movement would produce by rebound the suppression of the sensation to which this movement habitually corresponds. On this hypothesis, a sensation which loses its motor effect becomes useless, be it so, but this does not prove that the uselessness of a sensation is synonymous with insensibility. I can very well imagine the movement being suppressed and the useless sensation continuing to evoke images and to be perceived. Does this not occur daily? There are patients who, after an attack of paralysis, remain paralyzed in one limb, which loses the voluntary movement, but does not necessarily lose its sensibility. Many clear cases are observed in which this disassociation takes place. I therefore own that I cannot follow Mr. Bergson in his deduction. As a physiologist, I am obliged to believe firmly in the existence of the sensory nerves, and therefore I continue to suppose that our conscious sensations are consequent to the excitement of these nerves and subordinate to their integrity. Now, as therein lies, unless I mistake, the essential postulate, the heart of Mr. Bergson's theory, by not admitting it, I must regretfully reject the whole. A few convinced materialists and perilists to whom I have read the above criticisms on their systems have found no answer to them. My criticisms have appeared to them just, but nevertheless they have continued to abide by their own systems, probably because they were bound to have one. We do not destroy an erroneous idea when we do not replace it by another. This has decided me to set forth some personal views which, provisionally and for want of better, might be substituted for the old doctrines. Before doing this, I hasten to explain their character and to state openly that they are only hypotheses. I know that metaphysicians rarely make avails of this kind. They present their systems as a well connected whole, and they set forth its different parts, even the boldest of them, in the same dogmatic tone, and without warning that we ought to attach very unequal degrees of confidence to these various parts. This is a deplorable method, and to it is perhaps due the kind of disdain that observers and experimentalists feel for. Metaphysics, a disdain often without justification, though all is not false, and everything is not hypothetical in metaphysics. There are innate demonstrations, analysis and criticisms, especially the last, which appear to me as exact and as certain as an observation or experiment. The mistake lies in mixing up together in a statement, without distinction, the certain with the probable, and the probable with the possible. Metaphysicians are not wholly responsible for this folk of method, and I am much inclined to think that it is the natural consequence of the abuse of speculation. It is especially by the cultivation of the sciences of observation that we foster in ourselves the precious sense of proof, because we can check it any minute by experimental verification. When we are working at a distance from the facts, this sense of proof gets thinner, and there is lost that feeling of responsibility and fear of seeing one's assertions contradicted by a decisive, countervailing observation, which is felt by every observer. One acquires the unbearable pride which I note in Kant, and one abandons oneself to the spirit of construction. I am speaking from personal experience.  I have been seeking to group several facts of observation under the same idea, and then I have discovered that I was belittling and depreciating those facts which did not fit in with the idea. The hypothesis I now present on the relations of the mind and the brain has, for me, the advantage of bringing to light the precise conditions which a solution of this great problem must satisfy for this solution to be worthy of discussion. These conditions are very numerous. I shall not indicate them all successively, but here are two which are particularly important. One, the manifestations of the consciousness are conditioned by the brain. Let us suspend, by any means, the activity of the encephalic mess by arresting the circulation of the blood, for example, and the physical function is at once inhibited. Compress the carotide and you obtain the clouding over of the intellect, or instead of a total evolution. You can have one in detail.  Consciousness appears only when the molecular disturbance reaches the nerve centers. Everything takes place in the same way as if this disturbance released the consciousness. Consciousness also accompanies or follows certain material states of the nerve centers, such as the waves which traverse the sensory nerves, which exercise reflex action in the cells and which propagate themselves in the motor nerves. It is to the production of the distribution and the integrity of this nervous influx that the consciousness is closely linked. It there finds one of the conditions of its apparition. Two, on the other hand, the consciousness remains in complete ignorance of these incoherent cerebral phenomena. It does not perceive the nerve wave which sets it in motion. It knows nothing of its peculiarities, of its trajectory, or the length of its course. In this sense, it may be said that it is in no degree an anatomist. It has no idea of all the peculiarities of the nerve wave which form part of its cerebral history from the moment when these peculiarities are out of relation with the properties of external objects. One sometimes wonders that our consciousness is not aware that the objects we perceive with our two eyes correspond to a double undulation, namely that of the right and that of the left, and that the image is reversed on the retina, so that it is the rods of the right which are impressed by objects on our left, and the rods of the upper parts by objects below our eyes. These are, it has been very justly said, fictitious problems, imaginary difficulties which do not exist. There is no need to explain, for instance, direct vision by a reversed image, because our consciousness is not aware that the image on the retina is reversed. In order to take account of this, we should require another eye to see this image. This answer appears particularly to the point. It will be found that it is absolutely correct if we reflect that this case of the unfelt inversion of the image on the retina is but one example of the anatomonical ignorance of the consciousness. It might also be declared in the same order of ideas that our consciousness is ignorant, that excitements of the eye cross each other at the level of the chiasma and pass through the internal capsule, and that the majority of the visual excitements of an eye are received by the opposite hemisphere. A rather confused notion of these facts has formed itself in the minds of several critics, and I can discern the proof of this in the language they use. It will be said, for example, that the idea exists in the consciousness or in the mind, and phrases like the following will be avoided. I think with my brain, the suggestion consists in introducing an idea in the brain. The nerve cell perceives and reason etc. Ordinarily, these forms of speech are criticized because they appear to have the defect of establishing a confusion between two irreducible elements. The physical and the mental. I think the error of language proceeds from another cause since I do not admit this distinction between the physical and the mental. I think that the error consists in supposing vaguely that the consciousness comprehends intracellable phenomena, whereas it ignores them. Let me repeat that there is no such thing as intracellable sensibility. The consciousness is absolutely insensitive with regard to the dispositions of the cerebral substance and its mode of work. It is not the nervous undulation which our consciousness perceives, but the exciting cause of this wave, that is, the external object. The consciousness does not feel that which is quite close to it, but is informed of that which passes much further off. Nothing that is produced inside the cranium interests it. It is solely occupied with objects of which the situation is extra-cranial. It does not penetrate into the brain. We might say that it spreads itself like a sheet over the periphery of the body and then springs into the midst of the external objects. There is, therefore, I do not say a contradiction, but a very striking contrast between these two facts. The consciousness is conditioned, kept up, and nourished by the working of the cerebral substance, but knows nothing of what passes in the interior of that substance. This consciousness might itself be compared to a parasitical organism which plunges its tap roots into the nerve centers and of which the organs of perception, born on long stalks, emerge from the cranium and perceive everything outside that cranium. But this is, of course, only a rough image. Strictly, it is possible to explain this distribution of the consciousness, singular as it is at first sight, by those reasons of practical utility which are so powerful in the history of evolution. A living being has to know the world external to himself in order to adapt and pre-adapt himself to it. There it is in this outer world that he finds food, shelter, beings of his own species, and the means of work. And it is on this world of objects that he acts in every possible way by the contractions of his muscles. But with regard to the intrusive phallic actions they are outside the ordinary sphere of our actions. There is no daily need to know them. We can understand that the consciousness has not found very pressing utilitarian motives for development in that direction. One must be a histologist or a surgeon to find an appreciable interest in studying the structure of the nerve cell or the typography of the cerebral centers. We can therefore explain well enough by the general laws of adaption, the reason of the absence of which might be called cerebral sensibility, but here as elsewhere the question of the why is much easier to solve than that of the how. The question of the how consists in explaining that the consciousness directly aroused by a nerve wave does not perceive this undulation, but in its deed the external object. Let us first note that between the external object and the nervous influx there is the relation of cause to effect. It is only the effect which reaches us, our nerve cells and our consciousness. What must be explained is how a cognition, if such a word may be employed here, of the effect can excite the consciousness of the cause. It is clear that the effect does not resemble the cause as quality the orange I am looking at has no resemblance with the brain wave which at this moment is transversing my optic nerve, but this effect contains everything which was in the cause, or more exactly all that part of the cause of which we have perception. Since it is only by the intermediary of our nervous system that we perceive the object or the properties capable of being perceived are communicated to our nervous system and inscribed in the nerve wave. The effect produced therefore is the measure of our perception of the cause. This is absolutely certain. All bodies possesses an infinity of properties which escape our cognitions because as excitants of our organism these properties are wanting in the intensity of the quality necessary to make it vibrate. They have not been tuned in unison with our nervous cords and inversely all we perceive of the mechanical, physical and chemical properties of a body is contained in the vibration this body succeeds in propagating through our cerebral atmosphere. There is in this a phenomenon of transmission analogous to that which is produced when an air of music is sent along a wire. The whole concert heard at the other extremity of the wire has travelled in the form of delicate vibrations. They must therefore exist through unperceived biosensors a sort of kinship between the qualities of the external objects and the vibrations of our nerves. This is sometimes forgotten. The theory of the specific energy of the nerves cause it to be overlooked as we see that the quality of the sensation depends on the nerve that is excited, one who is inclined to minimise the importance of the excitant. It is relegated to the position of approximate cause with regard to the vibration of the nerve as the striking of the key on the piano is the approximate cause of the vibration of a string which always gives the same degree of sound whether struck by the forefinger or third finger or by a pencil or any other body. It will be seen at once that this comparison is inexact. The specific property of our nerves does not prevent our knowing the form of the excitant and our nerves are only comparable to piano strings if we grant to these the property of vibrating differently according to the nature of the bodies which strike them. How is it that the nerve wave if it be the depository of the whole of the physical properties perceived in the object resembles it so little? It is because this is my hypothesis these properties if they are in the undulation are not there alone. The undulation is the work of two collaborators it expresses both the nature of the object which provokes it and that of the nervous apparatus which is its vehicle. It is like the pharaoh traced in the wax of the phonograph which expresses the collaboration of an aerial vibration with a stylus a cylinder and a clockwork movement. This engraved line resembles in short neither the phonographic apparatus nor the aerial vibration although it results from the combination of the two. Similarly I suppose that if the nervous vibration resembles so little the excitant which gives it birth it is because the factor nervous system adds its effect to the factor external object. Each of these factors represents a different property the external object represents a cognition and the nervous system and excitement. Let us imagine that we succeed in separating these two effects it will be conceived theoretically that a separation of this kind will may be the hidden resemblances given to each collaborator the part which belongs to it. The excitement for instance will be suppressed and the cognition will be retained is it possible to make or at least to imagine such analysis perhaps for these two competing activities one is variable since it depends on the constantly changing nature of the objects which come into relation with us the other on the contrary is a constant since it expresses a contribution of our nerve substance and though this last is a very unstable composition it necessarily varies much less than the series of excitants. We consequently see faintly that these two elements stick us sufficiently in character for us to be able to suppose that they are separable by analysis but how could this analysis be made evidently not by chemical or physical means we have no need here of regents prisms centrifugal apparatus permeable membranes or anything of that kind it will suffice to suppose that it is the consciousness itself that is the dialyser it acts by virtue of its own laws that is to say by changes in intensity supposing that sensibility increases for the variable elements of the undulation and becomes insensible for the constant elements the effect will be the same as a material dissociation by chemical analysis there will be an elimination of certain elements and the retention of others now all we know of the consciousness authorizes us to entrust this role to it for it is within the range of its habits we know that change is the law of consciousness that it is a faced when the excitements are uniform and is renewed by their differences or their novelty a continued or two often repeated excitement ceases in time to be perceived it is to condense these facts into a formula that bane speaks of the law of relativity of cognition and in spite of a few ambiguities on the part of spencer and of bane himself in the definition of this law the formula with the sense I have just indicated is worth preserving let us see what becomes of it when my hypothesis is adopted it explains how certain excitements proceeding from the objects that is to say forming part of the variable element cease to be perceived when they are repeated and tend to become constant a photography it seems to me should the same law explain how the constant element par excellence the one which never varies from the first hour is never perceived there is in the concert of the sounds of nature and accompaniment so monotonous that it is no longer perceived and the melody alone continues to be heard it is in this precisely that my hypothesis consists we will suppose a nerve current starting from one of the organs of the senses when it is excited by some object or other and arriving at the center of the brain this current contains all the properties of the object its color its form its size its thousand details of structure its weight its sonorous qualities etc etc properties combined with and connected by the properties of the nerve organ in which the current is propagated the consciousness remains insensible to those nervous properties of the current which are so often repeated that they are an old it perceives on the contrary its variable and accidental properties which express the nature of the excitant by this partial sensibility the consciousness lays there that which in the nerve current represents the object that is to say a cognition and this operation is equivalent to a transformation of the current into a perception image or idea there is not strictly speaking a transformation but analysis only the practical result is the same as that of a transformation and is obtained without its being necessary to suppose the transmutation of a physical into a mental phenomenon let us place ourselves now at the moment when the analysis i am supposing to be possible has just been affected our consciousness then assists at the unrolling of representations which correspond to the outer world these representations are not or do not appear to be lodged in the brain and it is not necessary to suppose a special operation which taking them in the brain should project them into the periphery of our nerves this transport would be useless since for the consciousness the brain does not exist the brain with its fibers and cells is not felt it therefore supplies no datum to enable us to judge whether the representation is external or internal with regard to it in other words the representation is only localized in relation to itself there is no determinate position other than that of one representation in relation to another we may therefore reject as inexact the pretended law of eccentricity of the physiologists who suppose that sensation is first perceived as worse centrally and then by an added act is localized at the peripheric extremity of the nerve this argument would only be correct if we admitted that the brain is perceived by the consciousness of the brain i have already said that the consciousness is not an atomist and that therefore this problem does not present itself such as it is this hypothesis appears to me to present the advantage of explaining the reason why our consciousness coincides in certain circumstances with the actions of the brain and in others does not come near them in other words it contains an explanation of the unconscious i can show this by quoting certain exact facts of which the explanation has been hitherto thought to present difficulties but which become very easy to understand on the present hypothesis the first of these facts relates to the psychology of the motor current this current has been a great feature in the studies which have been made on the feeling of effort and on the physical basis of the wheel the motor current is at which starting from the cerebral cells of the motor region travels by way of the fibers of the pyramidal tract into the muscles of the body and it is centrifugal in direction researchers have been made as to whether we are or may be conscious of this current or rather the question has been put in somewhat different terms it has been asked whether a psychological state can be the counterpart of this motor current if for example the feeling of mental effort produced in us at the moment of executing a difficult act or of taking a grave resolution might not have this motor current for a basis the opinion which has prevailed is in the negative we have recognized a good deal on the faith of experiment and a little also for theoretical reasons that no sensation is awakened by the centrifugal current as to the sensation of effort it has been agreed to place it elsewhere we put it among the centripetal sensations which are produced as the movement outlines itself and which proceed from the contracted muscles the stretch ligaments and the frictional movements of the articulations if it would therefore form part of all the physical phenomenology which is the duplicate of those sensory currents which are centripetal in direction in the long run i can see no thought of theoretical reasons for subordinating the consciousness to the direction of the nerve current and for supposing that the consciousness is aroused when this current is centripetal and that it cannot follow the centrifugal current but this point matters little my hypotheses would fairly well explain why the motor current remains unconscious it explains the affair by taking into consideration the nature of this current and not its direction this current is a motor one because it is born in the central cells because it is a discharge from these cells and is of entirely nervous origin since it does not correspond with the perception of an object the ever varying object it is always the same by nature it does not carry within its monotonous course the debris of an object as does the sensory current thus it can flow without consciousness this same kind of hypothesis supplies us with the reasons why a given sensory current may be according to circumstances either conscience or unconscious the consciousness resulting from the analysis of the molecular wave is as it were a supplementary work which may be subsequently added to the realized wave the propagation of the wave is the essential fact there is always time to become conscious of that afterwards it is thus that we happen in moments of obstruction to remain insensible to certain even very powerful excitements our nervous system registers them nevertheless and we can find them again later on within the memory this is the effect of a belated analysis the converse phenomenon occurs much more frequently we remark many actions and perceptions which occur the first time with consciousness emotion and effort then when they are repeated as coordination becomes stronger and easier the reflex consciousness of the operation becomes fever this is the law of habit which slowly carries us towards automatism these observations have even been extended and the endeavor made to apply them to the explanation of the origin of reflex actions and of instincts which have all started with consciousness this is a rather bold attempt for it meets with many serious difficulties in execution but the idea seems fairly correct and is acceptable if we may limit it it is certain that the consciousness accompanies the effort towards the untried and perishes as soon as it is realized whence comes this singular dilemma propounded to it by nature to create something new or perish it really seems that my hypothesis explains this every new act is produced by nerve currents which contain many of those variable elements which the consciousness perceives but in proportion as the action of the brain repeats itself and becomes more precise and more exact this variable element becomes attenuated falls to its lowest pitch and may even disappear in the fixation of habit and instinct my hypothesis much resembles the system of parallelism it perfects it as it seems to me as much as the latter has perfected materialism we indeed admit a kind of parallelism between the consciousness and the object of cognition but these two series are not independent not simply placed in just a position as is possible in ordinary parallelism they are united and fused together so as to complete each other this new theory appears to me to represent a better form of the series of attempts which have been inspired by the common necessity of making the phenomena of consciousness accord with the determinism of physical facts i hold fast to this physical determinism and accept a strictly mechanical conception of the functions of the nervous system in my idea the currents which pass through the cerebral mass follow each other without interruption from the sensual periphery to the motor periphery it is they and they alone which excite the movements of the body by acting on the muscles parallelism recognizes all these things and i do likewise let us now see the advantages of this new system first it contains no parallelism no logical or physiological error since it does not advance the supposition that the mental differs by its nature from the physical phenomenon we have discussed above the consequences of this error they are here avoided in the second place it is explanatory at least in a certain measure since the formula we employ allows us to understand better than by the principle of simple just a position why certain nerve currents flow in the light of consciousness while others are plunged into the darkness of unconsciousness this law of consciousness which vane called the law of relativity becomes when embodied with my theory of the relations of the physical to the moral an explanation of the distribution of consciousness through the actions of the brain i ask myself whether the explanation i have devised ought to be literally preserved perhaps not i have endeavoured less to present a ready-made solution than to indicate the direction in which we ought to look for one the law of consciousness which i have used to explain the transformation of a nerve current into perception and images is only an empirical law produced by the generalization of particular observations until now there has been so far as i know no attempt to ascertain whether this law of consciousness notwithstanding the general nature which some authors inclined to ascribe to it might not explain itself by some more general facts and might not fit as a particular case into a more comprehensive frame to be brief this is very possible i have not troubled myself about it and i have made a transcendental use of this empirical law for i have been plightly supposed to be a first principle capable of accounting for the development of the consciousness but itself incapable of explanation if other observers discover that that which to me has appeared inexplicable may be explained by quite peculiar causes it is clear that my theory must be abandoned or modified new theories must then be sought for which will probably consist in recognizing different properties in the consciousness a little thought will discover several i have no doubt by way of suggestion i will indicate one of these hypothetical possibilities the consciousness has the faculty of reading in the effect that which existed in the cause it is not rash to believe that by working out this idea a certain solution would be discovered moreover the essential is i repeat less to find a solution than to take account of the point which requires one and metaphysics seemed to me especially useful when it shows us where the gap in our knowledge exists and what other conditions required to fill this gap above all idea to this idea which has been one of the guiding forces of this book there exists at the bottom of all the phenomena of the intelligence a duality to form a true phenomenon there must be at once a consciousness and an object according to passing tendencies either of temperament or a fashion preponderance has been given sometimes to one of the terms of this couple sometimes to the other the idealist declares thought creates the world the materialist answers the matter of the brain creates thought between these two extreme opinions the one as unjustifiable as the other in the excesses they commit we take up an intermediate position looking at the balance we see no argument capable of being placed in the scale of the consciousness which may not be neutralized by an argument placed in the scale of the object and if we had to give our final verdict we should say the consciousness and matter have equal rights thus leading to everyone the power to place in this conception of an equality of rights the hopes of survival of which his heart has need footnote the echo of arc perpetrated by bane and spencer consists in supposing that the consciousness bears solely on differences this is going too far i can find myself to admitting that if sensation is not changed from time to time the consciousness becomes weaker and disappears in a book three chapter five