Chapter II (2)

Nothing of the kind in the evolution of life. There, the disproportion is striking between the work and the result. From the bottom to the top of the organized world we do indeed find one great effort; but most often this effort turns short, sometimes paralyzed by contrary forces, sometimes diverted from what it should do by what it does, absorbed by the form it is engaged in taking, hypnotized by it as by a mirror. Even in its most perfect works, though it seems to have triumphed over external resistances and also over its own, it is at the mercy of the materiality which it has had to assume. It is what each of us may experience in himself. Our freedom, in the very movements by which it is affirmed, creates the growing habits that will stifle it if it fails to renew itself by a constant effort: it is dogged by automatism. The most living thought becomes frigid in the formula that expresses it. The word turns against the idea.

The letter kills the spirit. And our most ardent enthusiasm, as soon as it is externalized into action, is so naturally congealed into the cold calculation of interest or vanity, the one takes so easily the shape of the other, that we might confuse them together, doubt our own sincerity, deny goodness and love, if we did not know that the dead retain for a time the features of the living.

The profound cause of this discordance lies in an irremediable difference of rhythm. Life in general is mobility itself; particular manifestations of life accept this mobility reluctantly, and constantly lag behind. It is always going ahead; they want to mark time. Evolution in general would fain go on in a straight line; each special evolution is a kind of circle. Like eddies of dust raised by the wind as it passes, the living turn upon themselves, borne up by the great blast of life. They are therefore relatively stable, and counterfeit immobility so well that we treat each of them as a _thing_ rather than as a _progress_, forgetting that the very permanence of their form is only the outline of a movement. At times, however, in a fleeting vision, the invisible breath that bears them is materialized before our eyes. We have this sudden illumination before certain forms of maternal love, so striking, and in most animals so touching, observable even in the solicitude of the plant for its seed. This love, in which some have seen the great mystery of life, may possibly deliver us life's secret. It shows us each generation leaning over the generation that shall follow. It allows us a glimpse of the fact that the living being is above all a thoroughfare, and that the essence of life is in the movement by which life is transmitted.

This contrast between life in general, and the forms in which it is manifested, has everywhere the same character. It might be said that life tends toward the utmost possible action, but that each species prefers to contribute the slightest possible effort. Regarded in what constitutes its true essence, namely, as a transition from species to species, life is a continually growing action. But each of the species, through which life passes, aims only at its own convenience. It goes for that which demands the least labor. Absorbed in the form it is about to take, it falls into a partial sleep, in which it ignores almost all the rest of life; it fashions itself so as to take the greatest possible advantage of its immediate environment with the least possible trouble. Accordingly, the act by which life goes forward to the creation of a new form, and the act by which this form is shaped, are two different and often antagonistic movements. The first is continuous with the second, but cannot continue in it without being drawn aside from its direction, as would happen to a man leaping, if, in order to clear the obstacle, he had to turn his eyes from it and look at himself all the while.

Living forms are, by their very definition, forms that are able to live. In whatever way the adaptation of the organism to its circumstances is explained, it has necessarily been sufficient, since the species has subsisted. In this sense, each of the successive species that paleontology and zoology describes was a _success_ carried off by life. But we get a very different impression when we refer each species to the movement that has left it behind on its way, instead of to the conditions into which it has been set. Often this movement has turned aside; very often, too, it has stopped short; what was to have been a thoroughfare has become a terminus. From this new point of view, failure seems the rule, success exceptional and always imperfect. We shall see that, of the four main directions along which animal life bent its course, two have led to blind alleys, and, in the other two, the effort has generally been out of proportion to the result.

Documents are lacking to reconstruct this history in detail, but we can make out its main lines. We have already said that animals and vegetables must have separated soon from their common stock, the vegetable falling asleep in immobility, the animal, on the contrary, becoming more and more awake and marching on to the conquest of a nervous system. Probably the effort of the animal kingdom resulted in creating organisms still very simple, but endowed with a certain freedom of action, and, above all, with a shape so undecided that it could lend itself to any future determination. These animals may have resembled some of our worms, but with this difference, however, that the worms living to-day, to which they could be compared, are but the empty and fixed examples of infinitely plastic forms, pregnant with an unlimited future, the common stock of the echinoderms, molluscs, arthropods, and vertebrates.

One danger lay in wait for them, one obstacle which might have stopped the soaring course of animal life. There is one peculiarity with which we cannot help being struck when glancing over the fauna of primitive times, namely, the imprisonment of the animal in a more or less solid sheath, which must have obstructed and often even paralyzed its movements. The molluscs of that time had a shell more universally than those of to-day. The arthropods in general were provided with a carapace; most of them were crustaceans. The more ancient fishes had a bony sheath of extreme hardness.[59] The explanation of this general fact should be sought, we believe, in a tendency of soft organisms to defend themselves against one another by making themselves, as far as possible, undevourable. Each species, in the act by which it comes into being, trends towards that which is most expedient. Just as among primitive organisms there were some that turned towards animal life by refusing to manufacture organic out of inorganic material and taking organic substances ready made from organisms that had turned toward the vegetative life, so, among the animal species themselves, many contrived to live at the expense of other animals. For an organism that is animal, that is to say mobile, can avail itself of its mobility to go in search of defenseless animals, and feed on them quite as well as on vegetables. So, the more species became mobile, the more they became voracious and dangerous to one another. Hence a sudden arrest of the entire animal world in its progress towards higher and higher mobility; for the hard and calcareous skin of the echinoderm, the shell of the mollusc, the carapace of the crustacean and the ganoid breast-plate of the ancient fishes probably all originated in a common effort of the animal species to protect themselves against hostile species. But this breast-plate, behind which the animal took shelter, constrained it in its movements and sometimes fixed it in one place. If the vegetable renounced consciousness in wrapping itself in a cellulose membrane, the animal that shut itself up in a citadel or in armor condemned itself to a partial slumber. In this torpor the echinoderms and even the molluscs live to-day. Probably arthropods and vertebrates were threatened with it too. They escaped, however, and to this fortunate circumstance is due the expansion of the highest forms of life.

In two directions, in fact, we see the impulse of life to movement getting the upper hand again. The fishes exchanged their ganoid breast-plate for scales. Long before that, the insects had appeared, also disencumbered of the breast-plate that had protected their ancestors. Both supplemented the insufficiency of their protective covering by an agility that enabled them to escape their enemies, and also to assume the offensive, to choose the place and the moment of encounter. We see a progress of the same kind in the evolution of human armaments. The first impulse is to seek shelter; the second, which is the better, is to become as supple as possible for flight and above all for attack--attack being the most effective means of defense. So the heavy hoplite was supplanted by the legionary; the knight, clad in armor, had to give place to the light free-moving infantryman; and in a general way, in the evolution of life, just as in the evolution of human societies and of individual destinies, the greatest successes have been for those who have accepted the heaviest risks.

Evidently, then, it was to the animal's interest to make itself more mobile. As we said when speaking of adaptation in general, any transformation of a species can be explained by its own particular interest. This will give the immediate cause of the variation, but often only the most superficial cause. The profound cause is the impulse which thrust life into the world, which made it divide into vegetables and animals, which shunted the animal on to suppleness of form, and which, at a certain moment, in the animal kingdom threatened with torpor, secured that, on some points at least, it should rouse itself up and move forward.

On the two paths along which the vertebrates and arthropods have separately evolved, development (apart from retrogressions connected with parasitism or any other cause) has consisted above all in the progress of the sensori-motor nervous system. Mobility and suppleness were sought for, and also--through many experimental attempts, and not without a tendency to excess of substance and brute force at the start--variety of movements. But this quest itself took place in divergent directions. A glance at the nervous system of the arthropods and that of the vertebrates shows us the difference. In the arthropods, the body is formed of a series more or less long of rings set together; motor activity is thus distributed amongst a varying--sometimes a considerable--number of appendages, each of which has its special function. In the vertebrates, activity is concentrated in two pairs of members only, and these organs perform functions which depend much less strictly on their form.[60] The independence becomes complete in man, whose hand is capable of any kind of work.

That, at least, is what we see. But behind what is seen there is what may be surmised--two powers, immanent in life and originally intermingled, which were bound to part company in course of growth.

To define these powers, we must consider, in the evolution both of the arthropods and the vertebrates, the species which mark the culminating point of each. How is this point to be determined? Here again, to aim at geometrical precision will lead us astray. There is no single simple sign by which we can recognize that one species is more advanced than another on the same line of evolution. There are manifold characters, that must be compared and weighed in each particular case, in order to ascertain to what extent they are essential or accidental and how far they must be taken into account.

It is unquestionable, for example, that _success_ is the most general criterion of superiority, the two terms being, up to a certain point, synonymous. By success must be understood, so far as the living being is concerned, an aptitude to develop in the most diverse environments, through the greatest possible variety of obstacles, so as to cover the widest possible extent of ground. A species which claims the entire earth for its domain is truly a dominating and consequently superior species. Such is the human species, which represents the culminating point of the evolution of the vertebrates. But such also are, in the series of the articulate, the insects and in particular certain hymenoptera. It has been said of the ants that, as man is lord of the soil, they are lords of the sub-soil.

On the other hand, a group of species that has appeared late may be a group of degenerates; but, for that, some special cause of retrogression must have intervened. By right, this group should be superior to the group from which it is derived, since it would correspond to a more advanced stage of evolution. Now man is probably the latest comer of the vertebrates;[61] and in the insect series no species is later than the hymenoptera, unless it be the lepidoptera, which are probably degenerates, living parasitically on flowering plants.

So, by different ways, we are led to the same conclusion. The evolution of the arthropods reaches its culminating point in the insect, and in particular in the hymenoptera, as that of the vertebrates in man. Now, since instinct is nowhere so developed as in the insect world, and in no group of insects so marvelously as in the hymenoptera, it may be said that the whole evolution of the animal kingdom, apart from retrogressions towards vegetative life, has taken place on two divergent paths, one of which led to instinct and the other to intelligence.

Vegetative torpor, instinct, and intelligence--these, then, are the elements that coincided in the vital impulsion common to plants and animals, and which, in the course of a development in which they were made manifest in the most unforeseen forms, have been dissociated by the very fact of their growth. _The cardinal error which, from Aristotle onwards, has vitiated most of the philosophies of nature, is to see in vegetative, instinctive and rational life, three successive degrees of the development of one and the same tendency, whereas they are three divergent directions of an activity that has split up as it grew._ The difference between them is not a difference of intensity, nor, more generally, of degree, but of kind.

* * * * *

It is important to investigate this point. We have seen in the case of vegetable and animal life how they are at once mutually complementary and mutually antagonistic. Now we must show that intelligence and instinct also are opposite and complementary. But let us first explain why we are generally led to regard them as activities of which one is superior to the other and based upon it, whereas in reality they are not things of the same order: they have not succeeded one another, nor can we assign to them different grades.

It is because intelligence and instinct, having originally been interpenetrating, retain something of their common origin. Neither is ever found in a pure state. We said that in the plant the consciousness and mobility of the animal, which lie dormant, can be awakened; and that the animal lives under the constant menace of being drawn aside to the vegetative life. The two tendencies--that of the plant and that of the animal--were so thoroughly interpenetrating, to begin with, that there has never been a complete severance between them: they haunt each other continually; everywhere we find them mingled; it is the proportion that differs. So with intelligence and instinct. There is no intelligence in which some traces of instinct are not to be discovered, more especially no instinct that is not surrounded with a fringe of intelligence. It is this fringe of intelligence that has been the cause of so many misunderstandings. From the fact that instinct is always more or less intelligent, it has been concluded that instinct and intelligence are things of the same kind, that there is only a difference of complexity or perfection between them, and, above all, that one of the two is expressible in terms of the other. In reality, they accompany each other only because they are complementary, and they are complementary only because they are different, what is instinctive in instinct being opposite to what is intelligent in intelligence.

We are bound to dwell on this point. It is one of the utmost importance.

Let us say at the outset that the distinctions we are going to make will be too sharply drawn, just because we wish to define in instinct what is instinctive, and in intelligence what is intelligent, whereas all concrete instinct is mingled with intelligence, as all real intelligence is penetrated by instinct. Moreover, neither intelligence nor instinct lends itself to rigid definition: they are tendencies, and not things. Also, it must not be forgotten that in the present chapter we are considering intelligence and instinct as going out of life which deposits them along its course. Now the life manifested by an organism is, in our view, a certain effort to obtain certain things from the material world. No wonder, therefore, if it is the diversity of this effort that strikes us in instinct and intelligence, and if we see in these two modes of psychical activity, above all else, two different methods of action on inert matter. This rather narrow view of them has the advantage of giving us an objective means of distinguishing them. In return, however, it gives us, of intelligence in general and of instinct in general, only the mean position above and below which both constantly oscillate. For that reason the reader must expect to see in what follows only a diagrammatic drawing, in which the respective outlines of intelligence and instinct are sharper than they should be, and in which the shading-off which comes from the indecision of each and from their reciprocal encroachment on one another is neglected. In a matter so obscure, we cannot strive too hard for clearness. It will always be easy afterwards to soften the outlines and to correct what is too geometrical in the drawing--in short, to replace the rigidity of a diagram by the suppleness of life.

* * * * *

To what date is it agreed to ascribe the appearance of man on the earth? To the period when the first weapons, the first tools, were made. The memorable quarrel over the discovery of Boucher de Perthes in the quarry of Moulin-Quignon is not forgotten. The question was whether real hatchets had been found or merely bits of flint accidentally broken. But that, supposing they were hatchets, we were indeed in the presence of intelligence, and more particularly of _human_ intelligence, no one doubted for an instant. Now let us open a collection of anecdotes on the intelligence of animals: we shall see that besides many acts explicable by imitation or by the automatic association of images, there are some that we do not hesitate to call intelligent: foremost among them are those that bear witness to some idea of manufacture, whether the animal life succeeds in fashioning a crude instrument or uses for its profit an object made by man. The animals that rank immediately after man in the matter of intelligence, the apes and elephants, are those that can use an artificial instrument occasionally. Below, but not very far from them, come those that _recognize_ a constructed object: for example, the fox, which knows quite well that a trap is a trap. No doubt, there is intelligence wherever there is inference; but inference, which consists in an inflection of past experience in the direction of present experience, is already a beginning of invention. Invention becomes complete when it is materialized in a manufactured instrument. Towards that achievement the intelligence of animals tends as towards an ideal. And though, ordinarily, it does not yet succeed in fashioning artificial objects and in making use of them, it is preparing for this by the very variations which it performs on the instincts furnished by nature. As regards human intelligence, it has not been sufficiently noted that mechanical invention has been from the first its essential feature, that even to-day our social life gravitates around the manufacture and use of artificial instruments, that the inventions which strew the road of progress have also traced its direction. This we hardly realize, because it takes us longer to change ourselves than to change our tools. Our individual and even social habits survive a good while the circumstances for which they were made, so that the ultimate effects of an invention are not observed until its novelty is already out of sight. A century has elapsed since the invention of the steam-engine, and we are only just beginning to feel the depths of the shock it gave us. But the revolution it has effected in industry has nevertheless upset human relations altogether. New ideas are arising, new feelings are on the way to flower. In thousands of years, when, seen from the distance, only the broad lines of the present age will still be visible, our wars and our revolutions will count for little, even supposing they are remembered at all; but the steam-engine, and the procession of inventions of every kind that accompanied it, will perhaps be spoken of as we speak of the bronze or of the chipped stone of prehistoric times: it will serve to define an age.[62] If we could rid ourselves of all pride, if, to define our species, we kept strictly to what the historic and the prehistoric periods show us to be the constant characteristic of man and of intelligence, we should say not _Homo sapiens_, but _Homo faber_. In short, _intelligence, considered in what seems to be its original feature, is the faculty of manufacturing artificial objects, especially tools to make tools, and of indefinitely varying the manufacture_.

Now, does an unintelligent animal also possess tools or machines? Yes, certainly, but here the instrument forms a part of the body that uses it; and, corresponding to this instrument, there is an _instinct_ that knows how to use it. True, it cannot be maintained that _all_ instincts consist in a natural ability to use an inborn mechanism. Such a definition would not apply to the instincts which Romanes called "secondary"; and more than one "primary" instinct would not come under it. But this definition, like that which we have provisionally given of intelligence, determines at least the ideal limit toward which the very numerous forms of instinct are traveling. Indeed, it has often been pointed out that most instincts are only the continuance, or rather the consummation, of the work of organization itself. Where does the activity of instinct begin? and where does that of nature end? We cannot tell. In the metamorphoses of the larva into the nymph and into the perfect insect, metamorphoses that often require appropriate action and a kind of initiative on the part of the larva, there is no sharp line of demarcation between the instinct of the animal and the organizing work of living matter. We may say, as we will, either that instinct organizes the instruments it is about to use, or that the process of organization is continued in the instinct that has to use the organ. The most marvelous instincts of the insect do nothing but develop its special structure into movements: indeed, where social life divides the labor among different individuals, and thus allots them different instincts, a corresponding difference of structure is observed: the polymorphism of ants, bees, wasps and certain pseudoneuroptera is well known. Thus, if we consider only those typical cases in which the complete triumph of intelligence and of instinct is seen, we find this essential difference between them: _instinct perfected is a faculty of using and even of constructing organized instruments; intelligence perfected is the faculty of making and using unorganized instruments_.

The advantages and drawbacks of these two modes of activity are obvious. Instinct finds the appropriate instrument at hand: this instrument, which makes and repairs itself, which presents, like all the works of nature, an infinite complexity of detail combined with a marvelous simplicity of function, does at once, when required, what it is called upon to do, without difficulty and with a perfection that is often wonderful. In return, it retains an almost invariable structure, since a modification of it involves a modification of the species. Instinct is therefore necessarily specialized, being nothing but the utilization of a specific instrument for a specific object. The instrument constructed intelligently, on the contrary, is an imperfect instrument. It costs an effort. It is generally troublesome to handle. But, as it is made of unorganized matter, it can take any form whatsoever, serve any purpose, free the living being from every new difficulty that arises and bestow on it an unlimited number of powers. Whilst it is inferior to the natural instrument for the satisfaction of immediate wants, its advantage over it is the greater, the less urgent the need. Above all, it reacts on the nature of the being that constructs it; for in calling on him to exercise a new function, it confers on him, so to speak, a richer organization, being an artificial organ by which the natural organism is extended. For every need that it satisfies, it creates a new need; and so, instead of closing, like instinct, the round of action within which the animal tends to move automatically, it lays open to activity an unlimited field into which it is driven further and further, and made more and more free. But this advantage of intelligence over instinct only appears at a late stage, when intelligence, having raised construction to a higher degree, proceeds to construct constructive machinery. At the outset, the advantages and drawbacks of the artificial instrument and of the natural instrument balance so well that it is hard to foretell which of the two will secure to the living being the greater empire over nature.

We may surmise that they began by being implied in each other, that the original psychical activity included both at once, and that, if we went far enough back into the past, we should find instincts more nearly approaching intelligence than those of our insects, intelligence nearer to instinct than that of our vertebrates, intelligence and instinct being, in this elementary condition, prisoners of a matter which they are not yet able to control. If the force immanent in life were an unlimited force, it might perhaps have developed instinct and intelligence together, and to any extent, in the same organisms. But everything seems to indicate that this force is limited, and that it soon exhausts itself in its very manifestation. It is hard for it to go far in several directions at once: it must choose. Now, it has the choice between two modes of acting on the material world: it can either effect this action _directly_ by creating an _organized_ instrument to work with; or else it can effect it _indirectly_ through an organism which, instead of possessing the required instrument naturally, will itself construct it by fashioning inorganic matter. Hence intelligence and instinct, which diverge more and more as they develop, but which never entirely separate from each other. On the one hand, the most perfect instinct of the insect is accompanied by gleams of intelligence, if only in the choice of place, time and materials of construction: the bees, for example, when by exception they build in the open air, invent new and really intelligent arrangements to adapt themselves to such new conditions.[63] But, on the other hand, intelligence has even more need of instinct than instinct has of intelligence; for the power to give shape to crude matter involves already a superior degree of organization, a degree to which the animal could not have risen, save on the wings of instinct. So, while nature has frankly evolved in the direction of instinct in the arthropods, we observe in almost all the vertebrates the striving after rather than the expansion of intelligence. It is instinct still which forms the basis of their psychical activity; but intelligence is there, and would fain supersede it. Intelligence does not yet succeed in inventing instruments; but at least it tries to, by performing as many variations as possible on the instinct which it would like to dispense with. It gains complete self-possession only in man, and this triumph is attested by the very insufficiency of the natural means at man's disposal for defense against his enemies, against cold and hunger. This insufficiency, when we strive to fathom its significance, acquires the value of a prehistoric document; it is the final leave-taking between intelligence and instinct. But it is no less true that nature must have hesitated between two modes of psychical activity--one assured of immediate success, but limited in its effects; the other hazardous, but whose conquests, if it should reach independence, might be extended indefinitely. Here again, then, the greatest success was achieved on the side of the greatest risk. _Instinct and intelligence therefore represent two divergent solutions, equally fitting, of one and the same problem._

There ensue, it is true, profound differences of internal structure between instinct and intelligence. We shall dwell only on those that concern our present study. Let us say, then, that instinct and intelligence imply two radically different kinds of knowledge. But some explanations are first of all necessary on the subject of consciousness in general.

It has been asked how far instinct is conscious. Our reply is that there are a vast number of differences and degrees, that instinct is more or less conscious in certain cases, unconscious in others. The plant, as we shall see, has instincts; it is not likely that these are accompanied by feeling. Even in the animal there is hardly any complex instinct that is not unconscious in some part at least of its exercise. But here we must point out a difference, not often noticed, between two kinds of unconsciousness, viz., that in which consciousness is _absent_, and that in which consciousness is _nullified_. Both are equal to zero, but in one case the zero expresses the fact that there is nothing, in the other that we have two equal quantities of opposite sign which compensate and neutralize each other. The unconsciousness of a falling stone is of the former kind: the stone has no feeling of its fall. Is it the same with the unconsciousness of instinct, in the extreme cases in which instinct is unconscious? When we mechanically perform an habitual action, when the somnambulist automatically acts his dream, unconsciousness may be absolute; but this is merely due to the fact that the representation of the act is held in check by the performance of the act itself, which resembles the idea so perfectly, and fits it so exactly, that consciousness is unable to find room between them. _Representation is stopped up by action._ The proof of this is, that if the accomplishment of the act is arrested or thwarted by an obstacle, consciousness may reappear. It was there, but neutralized by the action which fulfilled and thereby filled the representation. The obstacle creates nothing positive; it simply makes a void, removes a stopper. This inadequacy of act to representation is precisely what we here call consciousness.

If we examine this point more closely, we shall find that consciousness is the light that plays around the zone of possible actions or potential activity which surrounds the action really performed by the living being. It signifies hesitation or choice. Where many equally possible actions are indicated without there being any real action (as in a deliberation that has not come to an end), consciousness is intense. Where the action performed is the only action possible (as in activity of the somnambulistic or more generally automatic kind), consciousness is reduced to nothing. Representation and knowledge exist none the less in the case if we find a whole series of systematized movements the last of which is already pre-figured in the first, and if, besides, consciousness can flash out of them at the shock of an obstacle. From this point of view, _the consciousness of a living being may be defined as an arithmetical difference between potential and real activity_. _It measures the interval between representation and action._

It may be inferred from this that intelligence is likely to point towards consciousness, and instinct towards unconsciousness. For, where the implement to be used is organized by nature, the material furnished by nature, and the result to be obtained willed by nature, there is little left to choice; the consciousness inherent in the representation is therefore counterbalanced, whenever it tends to disengage itself, by the performance of the act, identical with the representation, which forms its counterweight. Where consciousness appears, it does not so much light up the instinct itself as the thwartings to which instinct is subject; it is the _deficit_ of instinct, the distance, between the act and the idea, that becomes consciousness so that consciousness, here, is only an accident. Essentially, consciousness only emphasizes the starting-point of instinct, the point at which the whole series of automatic movements is released. Deficit, on the contrary, is the normal state of intelligence. Laboring under difficulties is its very essence. Its original function being to construct unorganized instruments, it must, in spite of numberless difficulties, choose for this work the place and the time, the form and the matter. And it can never satisfy itself entirely, because every new satisfaction creates new needs. In short, while instinct and intelligence both involve knowledge, this knowledge is rather _acted_ and unconscious in the case of instinct, _thought_ and conscious in the case of intelligence. But it is a difference rather of degree than of kind. So long as consciousness is all we are concerned with, we close our eyes to what is, from the psychological point of view, the cardinal difference between instinct and intelligence.

In order to get at this essential difference we must, without stopping at the more or less brilliant light which illumines these two modes of internal activity, go straight to the two _objects_, profoundly different from each other, upon which instinct and intelligence are directed.

When the horse-fly lays its eggs on the legs or shoulders of the horse, it acts as if it knew that its larva has to develop in the horse's stomach and that the horse, in licking itself, will convey the larva into its digestive tract. When a paralyzing wasp stings its victim on just those points where the nervous centres lie, so as to render it motionless without killing it, it acts like a learned entomologist and a skilful surgeon rolled into one. But what shall we say of the little beetle, the Sitaris, whose story is so often quoted? This insect lays its eggs at the entrance of the underground passages dug by a kind of bee, the Anthophora. Its larva, after long waiting, springs upon the male Anthophora as it goes out of the passage, clings to it, and remains attached until the "nuptial flight," when it seizes the opportunity to pass from the male to the female, and quietly waits until it lays its eggs. It then leaps on the egg, which serves as a support for it in the honey, devours the egg in a few days, and, resting on the shell, undergoes its first metamorphosis. Organized now to float on the honey, it consumes this provision of nourishment, and becomes a nymph, then a perfect insect. Everything happens _as if_ the larva of the Sitaris, from the moment it was hatched, knew that the male Anthophora would first emerge from the passage; that the nuptial flight would give it the means of conveying itself to the female, who would take it to a store of honey sufficient to feed it after its transformation; that, until this transformation, it could gradually eat the egg of the Anthophora, in such a way that it could at the same time feed itself, maintain itself at the surface of the honey, and also suppress the rival that otherwise would have come out of the egg. And equally all this happens _as if_ the Sitaris itself knew that its larva would know all these things. The knowledge, if knowledge there be, is only implicit. It is reflected outwardly in exact movements instead of being reflected inwardly in consciousness. It is none the less true that the behavior of the insect involves, or rather evolves, the idea of definite things existing or being produced in definite points of space and time, which the insect knows without having learned them.

Now, if we look at intelligence from the same point of view, we find that it also knows certain things without having learned them. But the knowledge in the two cases is of a very different order. We must be careful here not to revive again the old philosophical dispute on the subject of innate ideas. So we will confine ourselves to the point on which every one is agreed, to wit, that the young child understands immediately things that the animal will never understand, and that in this sense intelligence, like instinct, is an inherited function, therefore an innate one. But this innate intelligence, although it is a faculty of knowing, knows no object in particular. When the new-born babe seeks for the first time its mother's breast, so showing that it has knowledge (unconscious, no doubt) of a thing it has never seen, we say, just because the innate knowledge is in this case of a definite object, that it belongs to _instinct_ and not to _intelligence_. Intelligence does not then imply the innate knowledge of any object. And yet, if intelligence knows nothing by nature, it has nothing innate. What, then, if it be ignorant of all things, can it know? Besides _things_, there are _relations_. The new-born child, so far as intelligent, knows neither definite objects nor a definite property of any object; but when, a little later on, he will hear an epithet being applied to a substantive, he will immediately understand what it means. The relation of attribute to subject is therefore seized by him naturally, and the same might be said of the general relation expressed by the verb, a relation so immediately conceived by the mind that language can leave it to be understood, as is instanced in rudimentary languages which have no verb. Intelligence, therefore, naturally makes use of relations of like with like, of content to container, of cause to effect, etc., which are implied in every phrase in which there is a subject, an attribute and a verb, expressed or understood. May one say that it has _innate_ knowledge of each of these relations in particular? It is for logicians to discover whether they are so many irreducible relations, or whether they can be resolved into relations still more general. But, in whatever way we make the analysis of thought, we always end with one or several general categories, of which the mind possesses innate knowledge since it makes a natural use of them. Let us say, therefore, that _whatever, in instinct and intelligence, is innate knowledge, bears in the first case on_ things _and in the second on_ relations.

Philosophers distinguish between the matter of our knowledge and its form. The matter is what is given by the perceptive faculties taken in the elementary state. The form is the totality of the relations set up between these materials in order to constitute a systematic knowledge. Can the form, without matter, be an object of knowledge? Yes, without doubt, provided that this knowledge is not like a thing we possess so much as like a habit we have contracted,--a direction rather than a state: it is, if we will, a certain natural bent of attention. The schoolboy, who knows that the master is going to dictate a fraction to him, draws a line before he knows what numerator and what denominator are to come; he therefore has present to his mind the general relation between the two terms although he does not know either of them; he knows the form without the matter. So is it, prior to experience, with the categories into which our experience comes to be inserted. Let us adopt then words sanctioned by usage, and give the distinction between intelligence and instinct this more precise formula: _Intelligence, in so far as it is innate, is the knowledge of a_ form; _instinct implies the knowledge of a_ matter.

From this second point of view, which is that of knowledge instead of action, the force immanent in life in general appears to us again as a limited principle, in which originally two different and even divergent modes of knowing coexisted and intermingled. The first gets at definite objects immediately, in their materiality itself. It says, "This is what is." The second gets at no object in particular; it is only a natural power of relating an object to an object, or a part to a part, or an aspect to an aspect--in short, of drawing conclusions when in possession of the premisses, of proceeding from what has been learnt to what is still unknown. It does not say, "This _is_;" it says only that "_if_ the conditions are such, such will be the conditioned." In short, the first kind of knowledge, the instinctive, would be formulated in what philosophers call _categorical_ propositions, while the second kind, the intellectual, would always be expressed _hypothetically_. Of these two faculties, the former seems, at first, much preferable to the other. And it would be so, in truth, if it extended to an endless number of objects. But, in fact, it applies only to one special object, and indeed only to a restricted part of that object. Of this, at least, its knowledge is intimate and full; not explicit, but implied in the accomplished action. The intellectual faculty, on the contrary, possesses naturally only an external and empty knowledge; but it has thereby the advantage of supplying a frame in which an infinity of objects may find room in turn. It is as if the force evolving in living forms, being a limited force, had had to choose between two kinds of limitation in the field of natural or innate knowledge, one applying to the _extension_ of knowledge, the other to its _intension_. In the first case, the knowledge may be packed and full, but it will then be confined to one specific object; in the second, it is no longer limited by its object, but that is because it contains nothing, being only a form without matter. The two tendencies, at first implied in each other, had to separate in order to grow. They both went to seek their fortune in the world, and turned out to be instinct and intelligence.

Such, then, are the two divergent modes of knowledge by which intelligence and instinct must be defined, from the standpoint of knowledge rather than that of action. But knowledge and action are here only two aspects of one and the same faculty. It is easy to see, indeed, that the second definition is only a new form of the first.

If instinct is, above all, the faculty of using an organized natural instrument, it must involve innate knowledge (potential or unconscious, it is true), both of this instrument and of the object to which it is applied. Instinct is therefore innate knowledge of a _thing_. But intelligence is the faculty of constructing unorganized--that is to say artificial--instruments. If, on its account, nature gives up endowing the living being with the instruments that may serve him, it is in order that the living being may be able to vary his construction according to circumstances. The essential function of intelligence is therefore to see the way out of a difficulty in any circumstances whatever, to find what is most suitable, what answers best the question asked. Hence it bears essentially on the relations between a given situation and the means of utilizing it. What is innate in intellect, therefore, is the tendency to establish relations, and this tendency implies the natural knowledge of certain very general relations, a kind of stuff that the activity of each particular intellect will cut up into more special relations. Where activity is directed toward manufacture, therefore, knowledge necessarily bears on relations. But this entirely _formal_ knowledge of intelligence has an immense advantage over the _material_ knowledge of instinct. A form, just because it is empty, may be filled at will with any number of things in turn, even with those that are of no use. So that a formal knowledge is not limited to what is practically useful, although it is in view of practical utility that it has made its appearance in the world. An intelligent being bears within himself the means to transcend his own nature.

He transcends himself, however, less than he wishes, less also than he imagines himself to do. The purely formal character of intelligence deprives it of the ballast necessary to enable it to settle itself on the objects that are of the most powerful interest to speculation. Instinct, on the contrary, has the desired materiality, but it is incapable of going so far in quest of its object; it does not speculate. Here we reach the point that most concerns our present inquiry. The difference that we shall now proceed to denote between instinct and intelligence is what the whole of this analysis was meant to bring out. We formulate it thus: _There are things that intelligence alone is able to seek, but which, by itself, it will never find. These things instinct alone could find; but it will never seek them._

It is necessary here to consider some preliminary details that concern the mechanism of intelligence. We have said that the function of intelligence is to establish relations. Let us determine more precisely the nature of these relations. On this point we are bound to be either vague or arbitrary so long as we see in the intellect a faculty intended for pure speculation. We are then reduced to taking the general frames of the understanding for something absolute, irreducible and inexplicable. The understanding must have fallen from heaven with its form, as each of us is born with his face. This form may be defined, of course, but that is all; there is no asking why it is what it is rather than anything else. Thus, it will be said that the function of the intellect is essentially unification, that the common object of all its operations is to introduce a certain unity into the diversity of phenomena, and so forth. But, in the first place, "unification" is a vague term, less clear than "relation" or even "thought," and says nothing more. And, moreover, it might be asked if the function of intelligence is not to divide even more than to unite. Finally, if the intellect proceeds as it does because it wishes to unite, and if it seeks unification simply because it has need of unifying, the whole of our knowledge becomes relative to certain requirements of the mind that probably might have been entirely different from what they are: for an intellect differently shaped, knowledge would have been different. Intellect being no longer dependent on anything, everything becomes dependent on it; and so, having placed the understanding too high, we end by putting too low the knowledge it gives us. Knowledge becomes relative, as soon as the intellect is made a kind of absolute.--We regard the human intellect, on the contrary, as relative to the needs of action. Postulate action, and the very form of the intellect can be deduced from it. This form is therefore neither irreducible nor inexplicable. And, precisely because it is not independent, knowledge cannot be said to depend on it: knowledge ceases to be a product of the intellect and becomes, in a certain sense, part and parcel of reality.

Philosophers will reply that action takes place in an _ordered_ world, that this order is itself thought, and that we beg the question when we explain the intellect by action, which presupposes it. They would be right if our point of view in the present chapter was to be our final one. We should then be dupes of an illusion like that of Spencer, who believed that the intellect is sufficiently explained as the impression left on us by the general characters of matter: as if the order inherent in matter were not intelligence itself! But we reserve for the next chapter the question up to what point and with what method philosophy can attempt a real genesis of the intellect at the same time as of matter. For the moment, the problem that engages our attention is of a psychological order. We are asking what is the portion of the material world to which our intellect is specially adapted. To reply to this question, there is no need to choose a system of philosophy: it is enough to take up the point of view of common sense.

Let us start, then, from action, and lay down that the intellect aims, first of all, at constructing. This fabrication is exercised exclusively on inert matter, in this sense, that even if it makes use of organized material, it treats it as inert, without troubling about the life which animated it. And of inert matter itself, fabrication deals only with the solid; the rest escapes by its very fluidity. If, therefore, the tendency of the intellect is to fabricate, we may expect to find that whatever is fluid in the real will escape it in part, and whatever is life in the living will escape it altogether. _Our intelligence, as it leaves the hands of nature, has for its chief object the unorganized solid._

When we pass in review the intellectual functions, we see that the intellect is never quite at its ease, never entirely at home, except when it is working upon inert matter, more particularly upon solids. What is the most general property of the material world? It is extended: it presents to us objects external to other objects, and, in these objects, parts external to parts. No doubt, it is useful to us, in view of our ulterior manipulation, to regard each object as divisible into parts arbitrarily cut up, each part being again divisible as we like, and so on _ad infinitum_. But it is above all necessary, for our present manipulation, to regard the real object in hand, or the real elements into which we have resolved it, as _provisionally final_, and to treat them as so many _units_. To this possibility of decomposing matter as much as we please, and in any way we please, we allude when we speak of the _continuity_ of material extension; but this continuity, as we see it, is nothing else but our ability, an ability that matter allows to us to choose the mode of discontinuity we shall find in it. It is always, in fact, the mode of discontinuity once chosen that appears to us as the actually real one and that which fixes our attention, just because it rules our action. Thus discontinuity is thought for itself; it is thinkable in itself; we form an idea of it by a positive act of our mind; while the intellectual representation of continuity is negative, being, at bottom, only the refusal of our mind, before any actually given system of decomposition, to regard it as the only possible one. _Of the discontinuous alone does the intellect form a clear idea._