thinga already existing is absurd, no doubt, since the thing results from a solidification perfonned by our under- standing, and there are never any tilings other than those that the understanding has thus constituted. To spieak of things creating themselves would therefore amount to saying that the understanding presents to itself more than it presents to itself — a self-contradictory afiirmation, an empty and vain idea. But that action increases as it goes on, that it creates in the measure of its advance, IB what each of us finds when he watches himself act. Things are constituted by the instantaneous cut which the understanding practices, at a given moment, on a Qux of this kind, and what is mysterious when we compare the cuts together becomes clear when we relate them to the flux. Indeed, the modalities of creative action, in so far as it is still going on in the organization of bving forms, are much simplified when they are taken in this way. Before the complexity of an organism and the practically infinite multitude of interwoven analyses and syntheses it presupposes, our understanding recoils disconcerted. That the simple play of physical and chemical forces, left to themselves, should have worked this marvel, we find hard to believe. And if it is a profound science which is at work, how are we to understand the influence exercised on this matter without form by this form without matter? But the difficulty arises from this, that we represent statically ready-made material particles juxta- posed to one another, and, also statically, an external cause which plasters upon them a skilfully contrived organization. In reality, life is a movement, materiality is the inverse movement, and each of these two movements is simple, the matter which forms a world being an un- divided flux, and undivided also the life that runs through it, cutting out in it Uving beings all along its track. Of
250 CREATIVE EVOLUTION mST
these two currents the second runs counter to the first, but the first obtains, all the same, something from the second. There results between thera a modus vivendi, wh'':n is organization. This organization takes, for our £'jises and for our intellect, the form of parts entirely external to other parts in space and in time. Not only do we shut our eyes to the unity of the impulse which, passing through generations, links individuals with in- dividuals, species with species, and makes of the whole series of the living one single immense wave flowing over matter, but each individual itself seems to us as an aggre- gate, aggregate of molecules and aggregate of facts. The reason of this lies in the structure of our intellect, which is formed to act on matter from without, and which suc- ceeds by making, in the flux of the real, instantaneous cuts, each of which becomes, in its fixity, endlessly de- composable. Perceiving, in an organism, only parts external to parts, the understanding has the choice between two systems of explanation only: either to regard the infinitely complex {and thereby infinitely well-contrived) organization as a fortuitous concatena- tion of atoms, or to relate it to the incomprehensible influence of an external force that has grouped its ele- ments together. But this complexity is the work of the understanding; this incomprehensibility is also its work. Let us try to see, no longer with the eyes of the intellect alone, which grasps only the already made and which looks from the outside, but with the spirit, I mean with that faculty of seeing which is immanent in the faculty of acting and which springs up, somehow, by the twisting of the will on itself, when action is turned into knowledge, like heat, so to say, into light. To movement, then, everything will be restored, and into movement everything will be resolved. Where the un-
Ideal Genesis of Matter 251
derstanding, working on the image supposed to be fixed of the progressing action, shows us parts infinitely mani- fold and an order infinitely well contrived, we catch a glimpse of a simple process, an action which is making itself across an action of the same kind which is unmaking itself, like the fiery path torn by the last rocket of a fire- works display through the black cinders of the spent rockets that are f allin g dead. *
From this point of view, the general considerations
we have presented concerning the evolution of life will
be cleared up and completed. We will distinguish more
sharply what is accidental from what is essential in this
evolution.
The impetus of life, of which we are speaking, consists in a need of creation. It cannot create absolutely, be- cause it is confronted with matter, that is to say with the movement that is the inverse of its own. But it seizes upon this matter, which is necessity itself, and strives to introduce into it the largest possible amount of indeter- mination and liberty. How does it go to work?
Ad animal high in the scale may be represented in a general way, we said, as a sensori-motor nervous system imposed on digestive, respiratory, circulatory systems, etc. The function of these latter is to cleanse, repair and protect the nervous system, to make it as independent as possible of external circumstances, but, above all, to furnish it with energy to be expended in movements. The increasing complexity of the organism is therefore due theoretically (in spite of innumerable exceptions due to accidents of evolution) to the necessity of complexity in the nervous system. No doubt, each complication of any part of the organism involves many others in ad- dition, because this part itself must hve, and every change
in one point of the body reverberates, as it were, through- out. The complication may therefore go on to infinity in all directions; but it is the complication of the nervous system which conditions the others in right, if not always in fact. Now, in what does the progress of the nervous system itself consist? In a simultaneous development of automatic activity and of voluntary activity, the firet furnishing the second with an appropriate instrument. Thus, in an organism such as ours, a considerable number of motor mechanisms are set up in the medulla and in the spinal cord, awaiting only a signal to release the correspond- ing act: the will is employed, in some cases, in setting up the mechanism itself, and in the others in choosing the mechanisms to be released, the manner of combining them and the moment of releasing them. The will of an animal is the more effective and the more intense, the greater the number of the mechanisms it can choose from, the more complicated the switchboard on which all the motor paths cross, or, in other words, the more developed its brain. Thus, the progress of the nervous sj-stem assures to the act increasing precision, increasing variety, in- creasing efficiency and independence. The organism be- haves more and more like a machine for action, which reconstructs itself entirely for every new act, as if it were made of india-rubber and could, at any moment, change the shape of all its parts. But, prior to the nervous system, prior even to the organism properly so called, already in the undifferentiated mass of the amoeba, this essential property of animal life is found. The amoeba deforms itself in varying directions; its entire mass does what the differentiation of parts will localize in a sensori- motor system in the developed animal. Doing it only in a rudimentary manner, it is dispensed from the com- plexity of the higher organisms; there is no need here of
in.i
The Meaning of Evolution
the auxiliary elements that pass on to motor elements the energy to expend; the animaJ moves as a whole, and, as a whole also, procures energy by means of the organic substances it assimilates. Thus, whether low or high in the animal scale, we always End that animal life consists ( (1) in procuring a provision of energy; (2) in expending it, by means of a matter as supple as possible, in directions variable and unforeseen.
Now, whence comes the energy? From the ingested food, for food is a kind of explosive, which needs only the spark to discharge the energy it stores. Who has made this explosive? The food may be the flesh of an animal nourished on animals and so on; but, in the end it is to the vegetable we always come back. Vegetables alone gather in the solar energy, and the animals do but borrow it from them, cither directly or by some passing it on to others. How then has the plant stored up this energy? Chiefly by the chlorophyllian function, a chem- iciism sui generis of which we do not possess the key, and which is probably unlike that of our laboratories. The process consists in using solar energy to fix the carbon of carbonic acid, and thereby to store this energy as we should store that of a water-carrier by employing him to fill an elevated reservoir: the water, once brought up, can set in motion a mill or a turbine, as we will and when we will. Each atom of carbon fixed represents something like the elevation of the weight of water, or like the stretch- ing of an elastic thread uniting the carbon to the oxygen in the carbonic acid. The clastic is relaxed, the weight falls back again, in short the energy held in reserve is restored, when, by a simple release, the carbon is per- mitted to rejoin its oxygen.
So that all life, animal and vegetable, seems in its essence like an effort to accumulate energy and then to let it
pmuf.
flow into flexible channels, changeable in shape, at the end of which it will accomplish infinitely VEiried Idnds of work. That is what the vital impetus, passing through matter, would fain do all at once. It would succeed, no doubt, if its power were unlimited, or if some reinforce- ment could come to it from without. But the impetus is finite, and it has been given once for all. It cannot overcome all obstacles. The movement it starts is some- times turned aside, sonnetimes divided, always opposed; and the evolution of th« organized world is the unrolling of this conflict. The first great scission that had to be effected was that of the two kingdoms, vegetable and animal, which thus happen to be mutually complementary, without, however, any agreement having been made between them. It is not for the animal that the plant accumulates energy, it is for its own consumption; but its expenditure on itself is less discontinuous, and less concentrated, and therefore less eflicacious, than was required by the initial impetus of life, essentially directed toward free actions; the same organism could not with equal force sustain the two functions at once, of gradual storage and sudden use. Of themselves, therefore, and without any external intervention, simply by the effect of the duality of the tendency involved in the original impetus and of the resistance opposed by matter to this impetus, the organisms leaned some in the first direction, others in the second. To this scission there succeeded many others. Hence the diverging lines of evolution, at least what is essential in them. But we must take into account retrogressions, arrests, accidents of every kind. And we must remember, above all, that each species behaves as if the general movement of life stopped at it instead of passing through it. It thinks only of itself, it lives only for itself. Hence the numberless struggles
in.]
The Meaning Op Evolution
that we behold in nature. Hence a discord, striking
and terrible, but for which the original principle of life
must not be held responsible.
The part played by contingency in evolution is there- fore great. Contingent, generally, are the forms adopted, or rather invented. Contingent, relative to the obstacles encountered in a given place and at a given moment, is the dissociation of the primordial tendency into such and such complementary tendencies which create divergent lines of evolution. Contingent the arrests and set-backs; contingent, in large measure, the adaptations. Two things only are necessary: (1} a gradual accumulation of energy; (2) an elastic canalization of this energy in variable and indeterminable directions, at the end of which are free acts.