has a real cause, that it emanates from a force. But we must understand what we mean by this last word. In natural science force is only a function of mass and velocity: it is measured by acceleration: it is known and estimated only by the movements which it is supposed to produce in space. One with these movements, it shares their relativity. Hence the physicists, who seek the principle of absolute motion in force so denned, are led by the logic of their system back to the hypothesis of an absolute space which they had^at first desired to avoid.1 So it will be come necessary to take refuge in the metaphy sical sense of the word, and attribute the motion which we perceive in space to profound causes, analogous to those which our consciousness be lieves it discovers within the feeling of effort. But is the feeling of effort really the sense of a profound cause? Have not decisive analyses shown that there is nothing in this feeling other than the consciousness of movements already effected or begun at the periphery of the body? It is in vain, then, that we seek to found the reality of motion on a cause which is distinct from it: analysis always brings us back to motion itself.
But why seek elsewhere? So long as we apply a movement to the line along which it passes, the same point will appear to us, by turns, accord ing to the points or the axes to which we * Newton, in particular.
258 MATTER AND MEMORY CHAP, iv refer it, either at rest or in movement. But it is otherwise if we draw out of the movement the mobility which is its essence. When my eyes give me the sensation of a movement, this sensation is a reality, and something is effectually going on, whether it be that an object is changing its place before my eyes or that my eyes are moving before the object. A fortiori am I assured of the reality of the movement when I produce it after having willed to produce it, and my muscular sense brings me the consciousness of it. That is to say, I grasp the reality of movement when it appears to me, within me, as a change of state or of quality. But then how should it be otherwise when I perceive changes of quality in things? Sound differs absolutely from silence, as also one sound from another sound. Between light and darkness, between colours, between shades, the difference is absolute. The passage from one to another is also an absolutely real phenomenon. I hold then the two ends of the chain, muscular sensations within me, the sensible qualities of matter without me, and neither in the one case nor in the other do I see movement, if there be movement, as a mere relation: it is an absolute. Now, between these two extremities lie the movements of external bodies, properly so called. How are we to distinguish here between real and apparent movement? Of what object, exter nally perceived, can it be said that it moves, of what other that it remains motionless? To put CHAP, iv PERCEPTION AND MATTER 25Q such a question is to admit that the discontinuity established by common sense between objects independent of each other, having each its indi viduality, comparable to kinds of persons, is a valid distinction. For, on the contrary hypothesis, the question would no longer be how are pro duced in given parts of matter changes of posi tion, but how is effected in the whole a change of aspect, — a change of which we should then have to ascertain the nature. Let us then formulate at once our third proposition: — ///. All division of matter into independent bodies with absolutely determined outlines is an artificial division.
A body, that is, an independent material object, presents itself at first to us as a system of qualities The division oi m which resistance and colour — the data of sight and touch— occupy the centre, a11 tne rest being> ^ ^ were> suspended from them. On the °ther hand> the we w!Srif data °* signt and touch are those which most obviously have extension in space, an(j ^he essential character of space is continuity. There are intervals of silence between sounds, for the sense of hearing is not always oc cupied; between odours, between tastes, there are gaps, as though the senses of smell and taste only functioned accidentally: as soon as we open our eyes, on the contrary, the whole field of vision takes on colour; and, since solids are necessarily in contact with each other, our touch must follow 2OO MATTER AND MEMORY CHAP, iv the surface or the edges of objects without ever encountering a true interruption. How do we parcel out the continuity of material extensity, given in primary perception, into bodies of which each is supposed to have its substance and in dividuality? No doubt the aspect of this con tinuity changes from moment to moment; but why do we not purely and simply realize that the whole has changed, as with the turning of a kaleidoscope? Why, in short, do we seek, in the mobility of the whole, tracks that are supposed to be followed by bodies supposed to be in motion? A moving continuity is given to us, in which every thing changes and yet remains: whence comes it that we dissociate the two terms, permanence and change, and then represent permanence by bodies and change by homogeneous movements in space? This is no teaching of immediate intuition; but neither is it a demand of science, for the object of science is, on the contrary, to rediscover the natural articulations of a universe we have carved artificially. _ Nay more, science, as we shall see, by an evermore complete demonstration of the reciprocal action of all material points upon each other, returns, in spite of appearances, to the idea of an universal continuity. Science and conscious ness are agreed at bottom, provided that we re gard consciousness in its most immediate data, and science in its remotest aspirations. Whence comes then the irresistible tendency to set up a material universe that is discontinuous, composed CHAP, iv PERCEPTION AND MATTER 261 of bodies which have clearly defined outlines and change their place, that is, their relation with each other?
Besides consciousness and science, there is life. Beneath the principles of speculation, so carefully it is the analysed by philosophers, there are ten- ofe°ii^ing?s dencies of which the study has been neg- tiiat mark lected, and which are to be explained consciousness simply by the necessity of living, that distinct. -.. A,,, distinct. -.. A,,, bodies. is, of acting. Already the power con ferred on the individual consciousness of mani festing itself in acts requires the formation of distinct material zones, which correspond re spectively to living bodies: in this sense my own body and, by analogy with it, all other living bodies are those which I have the most right to distinguish in the continuity of the universe. But this body itself, as soon as it is constituted and distinguished, is led by its various needs to distinguish and constitute other bodies. In the humblest living being nutrition demands research, then contact, in short a series of efforts which converge towards a centre: this centre is just what is made into an object — the object which will serve as food. Whatever be the nature of matter, it may be said that life will at once establish in it a primary discontinuity, expressing the duality of the need and of that which must serve to satisfy it. But the need of food is not the only need. Others group themselves round it, all having for object the 262 MATTER AND MEMORY CHAP, iv conservation of the individual or of the spe cies; and each of them leads us to distin guish, besides our own body, bodies inde pendent of it which we must seek or avoid. Our needs are, then, so many search-lights which, directed upon the continuity of sensible qualities, single out in it distinct bodies. They cannot satisfy themselves except upon the condition that they carve out, within this continuity, a body which is to be their own, and then delimit other bodies with which the first can enter into relation, as if with persons. To establish these special relations among portions thus carved out from sensible reality is just what we call living. But if this first subdivision of the real answers much less to immediate intuition than to the But, to get a fundamental needs of life, are we likely fheipJOBhicml to gain a nearer knowledge of things by we mnrt'rejtct Pushing the division yet further? In this ?mSary waY we do indeed prolong the vital move- ?rac5cafy merit; but we turn our back upon true needs. knowledge. That is why the rough and ready operation, which consists in decomposing the body into parts of the same nature as itself, leads us down a blind alley, where we soon feel ourselves incapable of conceiving either why this division should cease or how it could go on ad infinitum. It is nothing, in fact, but the ordinary condition of useful action, unsuitably transported into the domain of pure know ledge. We shall never explain by means of CHAP, iv PERCEPTION AND MATTER 263 particles, whatever these may be, the simple pro perties of matter: at most we can thus follow out into corpuscles as artificial as the corpus — the body itself — the actions and reactions of this body with regard to all the others. This is pre cisely the object of chemistry. It studies bodies rather than matter; and so we understand why it stops at the atom, which is still endowed with the general properties of matter. But the ma teriality of the atom dissolves more and more under the eyes of the physicist. We have no reason, for instance, for representing the atom to ourselves as a solid, rather than as liquid or gaseous, nor for picturing the reciprocal action of atoms by shocks rather than in any other way. Why do we think of a solid atom, and why of shocks? Because solids, being the bodies on which we clearly have the most hold, are those which interest us most in our relations with the external world; and because contact is the only means which appears to be at our disposal in order to make our body act upon other bodies. But very simple experiments show that there is never true contact between two neighbouring bodies l; and besides, solidity is far from being an absolutely defined state of matter.8 Solidity and shock borrow, then, their apparent clearness 1 See, on this subject, Clerk- Maxwell, Action at a Distance (Scientific Papers, Cambridge, 1890, vol. ii, pp. 313-314).
z Clerk-Maxwell, Molecular Constitution of Bodies (Scientific Papers, vol. ii, p. 618). — Van der Waals has shown, on the other hand, the continuity of liquid and gaseous states.
264 MATTER AND MEMORY CHAP, rr from the habits and necessities of practical life; — images of this kind throw no light on the inner nature of things.
Moreover, if there is a truth that science has placed beyond dispute, it is that of the reciprocal action of all parts of matter upon each other. Between the supposed molecules of bodies the forces of attraction and repulsion are at work. The influence of gravitation extends throughout interplanetary space. Something, then, exists be tween the atoms. It will be said that this some thing is no longer matter, but force. And we shall be asked to picture to ourselves, stretched between the atoms, threads which will be made more and more tenuous, until they are invisi ble and even, we are told, immaterial. But what purpose can this crude image serve? The preservation of life no doubt requires that we should distinguish, in our daily experience, between passive things and actions effected by these things in space. As it is useful to us to fix the seat of the thing at the precise point where we might touch it, its palpable outlines become for us its real limit, and we then see in its action a something, I know not what, which, being altogether different, can part company with it. But since a theory of matter is an attempt to find the reality hidden beneath these customary images which- are entirely relative to our needs, from these images it must first of all set itself free. And, indeed, we see force and matter drawing nearer together the CHAP, nr PERCEPTION AND MATTER 265 more deeply the physicist has penetrated into their effects. We see force more and more materialized, the atom more and more idealized, the two terms converging towards a common limit and the uni verse thus recovering its continuity. We may still speak of atoms; the atom may even retain its individuality for our mind which isolates it; but the solidity and the inertia of the atom dissolve either into movements or into lines of force whose reciprocal solidarity brings back to us universal continuity. To this conclusion were bound to come, though they started from very different positions, the two physicists of the last century who have most closely investigated the consti tution of matter, Lord Kelvin and Faraday. For Faraday the atom is a centre of force. He means by this that the individuality of the atom consists in the mathematical point at which cross, radiating throughout space, the indefinite lines of force which really constitute it: thus each atom occupies the whole space to which gravita tion extends and all atoms are interpenetrating.1 Lord Kelvin, moving in another order of ideas, supposes a perfect, continuous, homogeneous and incompressible fluid, filling space: what we term an atom he makes into a vortex ring, ever whirl ing in this continuity, and owing its properties to its circular form, its existence and consequently 1 Faraday, A Speculation concerning Electric Conduction (Philos. Magazine, 3rd series, vol. xxiv).
266 MATTER AND MEMORY CHAP, iv its individuality to its motion.1 But on either hypothesis, the nearer we draw to the ultimate elements of „ matter the better we note the van ishing of thkt discontinuity which our senses per ceived oifcthe surface. Psychological analysis has already /revealed to us that this discontinuity is relative to our needs: every philosophy of nature ends by finding it incompatible with the general properties of matter.
In truth, vortices and lines of force are never, to the mind of the physicist, more than convenient figures for illustrating his calculations. But philo sophy is bound to ask why these symbols are more convenient than others, and why they permit of further advance. Could we, working with them, get back to experience, if the notions to which they correspond did not at least point out the direction in which we may seek for a representa tion of the real? Now the direction which they indicate is obvious; they show us, pervading concrete extensity, modifications, perturbations, changes of tension or of energy, and nothing else. It is by this, above all, that they tend to unite with the purely psychological analysis of motion which we considered to begin with, an analysis which presented it to us not as a mere change of relation between objects to which it was, as it 1 Thomson, On Vortex Atoms (Proc. of the Roy. Soc. of Edin., 1867). An hypothesis of the same nature had been put forward by Graham, On the Molecular Mobility of Gases (Proc. of the Roy. Soc., 1863, p. 621 et seq.).
CHAP, iv DURATION AND TENSION 267 were, an accidental addition, but as a true and, in some sort, an independent, reality. Neither science nor consciousness, then, is opposed to this last proposition: — IV. Real movement is rather the transference of a state than of a thing.
By formulating these four propositions, we have, in reality, only been progressively narrowing the interval between the two terms So we shall,.,...-, •, see real which it IS USUal to ODDOSC to each movement as.
rather other, — qualities or sensations, and quality than ' quantity, movements. At first sight, the distance and, as such,. °.
akin to appears impassable. Qualities are consciousness. rf ** heterogeneous, movements homogene ous. Sensations, essentially indivisible, escape measurement; movements, always divisible, are distinguished by calculable differences of direction and velocity. We are fain to put qualities, in the form of sensations, in consciousness; while move ments are supposed to take place independently of us in space. These movements, compounded together, we confess, will never yield anything but movements; our consciousness, though in capable of coming into touch with them, yet by a mysterious process is said to translate them into sensations, which afterwards project themselves into space and come to overlie, we know not how, the movements they translate. Hence two differ ent worlds, incapable of communicating otherwise than by a miracle, — on the one hand that of motion 268 MATTER AND MEMORY CHAP, iv in space, on the other that of consciousness with sensations. Now, certainly the difference is irre ducible (as we have shown in an earlier work *) between quality on the one hand and pure quan tity on the other. But this is just the question: do real movements present merely differences of quantity, or are they not quality itself, vibra ting, so to speak, internally, and beating time for its own existence through an often incal culable number of moments? Motion, as studied in mechanics, is but an abstraction or a sym bol, a common measure, a common denomina tor, permitting the comparison of all real move ments with each other; but these movements, regarded in themselves, are indivisibles which occupy duration, involve a before and an after, and link together the successive moments of time by a thread of variable quality which cannot be without some likeness to the continuity of our own consciousness. May we not conceive, for instance, that the irreducibility of two perceived colours is due mainly to the narrow duration into which are contracted the billions of vibrations which they execute in one of our moments? If we could stretch out this duration, that is to say, live it at a slower rhythm, should we not, as the rhythm slowed down, see these colours pale and lengthen into successive impressions, still coloured, no doubt, but nearer and nearer to coincidence 1 H. Bergson, Time and Free Will. Sonnenschein & Co.
CHAP, iv DURATION AND TENSION 269 with pure vibrations? In cases where the rhythm of the movement is slow enough to tally with the habits of our consciousness, — as in the case of the deep notes of the musical scale, for instance, — do we not feel that the quality perceived analyses itself into repeated and successive vibrations, bound together by an inner continuity? That which usually hinders this mutual approach of motion and quality is the acquired habit of attach ing movement to elements — atoms or what not, — which interpose their solidity between the move ment itself and the quality into which it contracts. As our daily experience shows us bodies in motion, it appears to us that there ought to be, in order to sustain the elementary movements to which qualities may be reduced, diminutive bodies or corpuscles. Motion becomes then for our imagin ation no more than an accident, a series of posi tions, a change of relations; and, as it is a law of our representation that in it the stable drives away the unstable, the important and central element for us becomes the atom, between the successive positions of which movement then be comes a mere Hnk. But not only has this concep tion the inconvenience of merely carrying over to the atom all the problems raised by matter; not only does it wrongly set up as an absolute that division of matter which, in our view, is hardly anything but an outward projection of human needs; it also renders unintelligible the process by which we grasp, in perception, at one and the same time, a 27O MATTER AND MEMORY CHAP, rv