If we class under the name instinct not one special faculty but the ensemble of all instincts, that is to say, innate automatism, whatever its origin may be, we may say with Bergson that instinct and intelligence "are not things of the same order," that they "diverge more and more in their development," but that "they never completely separate from each other." They are both "opposites and complements" and they assist each other.
On the one hand, indeed, the most perfect instinct of the insect is accompanied by certain gleams of intelligence, be it only in the choice of place, time, or material of construction. When, exceptionally, bees build in the open, they invent new and truly intelligent arrangements to meet the new conditions. But on the other hand, intelligence has still more need for instinct than instinct for intelligence, for the ability to work with raw material presupposes in the animal a superior grade of organization, to which it could have risen only on the wings of instinct.
Before such evidence Fabre was forced to modify his theory of immutable instinct. He says:
Pure instinct alone would leave the insect disarmed in the perpetual conflict of circumstances. ... A guide is necessary in this confused mix-up. . . . The insect surely has this guide in high degree. This is the second domain of its psychic powers. Here it is conscious and perfectible by experience. Not daring to designate this rudimentary aptitude as intelligence, a title too high for it, I shall call it discernment.
But is not discernment in this sense really a form of intelligence?
Such is the measure in which instinct and intelligence are associated in animals. If, with Berg-son, we regard consciousness "as proportional to the power of choice at the will of the animal," it will be evident that consciousness must be singularly obscure in all instinctive acts, but that on the contrary it must accompany all intelligent acts. Bergson, however, regards consciousness in a peculiar light, since he considers it as life "projected through matter," as the common source from which have sprung in different directions both instinct and intelligence. This leads us away from the common concept which sees in consciousness the torch which enlightens our actions. It is possible, even probable, that a consciousness of this kind exists to a greater or less extent in the animals. However, we cannot know anything about it, and we believe with Edmond Claparède1 that "animal psychology can and must scrutinize the problem of the greater or less intelligence of animals without being concerned with their consciousness."
In its simplest form intelligence reveals itself to us in a choice between the various alternatives offered by circumstances, and in one of its highest forms in the power of invention which, according to Bergson, enables the human race to "manufacture artificial objects, especially to make tools with which to make other tools and to vary their fabrication indefinitely." These two extreme forms are naturally connected by many intermediaries, and we know that both play a part in the behavior of articulates. The latter seems, however, to be rather exceptional in the group, and shows itself only in a primitive stage which consists of the use of foreign bodies as implements. With Ammophila urnaria the tool is a small stone with which the female rams and packs the dirt that closes her burrow. With certain ants of India (Cecophylla smaragdina) and of Brazil (Camponotus textor) the instrument consists of the larvae of the same species which, held between the mandibles of the workers, glue and fasten the leaves of which the nest is constructed, edge to edge, with their thread. The implement of the crabs of the genus Melici, in the Indo-Pacific seas, is a delicate sea anemone which, held between the pincers of the animal, probably serves to paralyze its prey by its urticating exudations.
1 Ed. Claparède, Les animaux sont-ils conscients?. .1901. (Revue phil, v. 26, pp. 481-498).
Facts of this kind are rare in the world of the articulates, but they have an important significance. The use of the stone is not yet a fixed habit with Ammophila urnaria; it belongs only to certain more highly endowed individuals with whom, perhaps, it is only an accident. Possibly it will finally pass into the instinctive habits of the species ; for the present it remains in the class of individual and intelligent acts. The crabs of the genus Melia are already beyond this stage, since all the species carry anemones and all have a curious modification of the pincers, the fine teeth having become elongated into needles which give them a better hold on their guest-tool. The adaptation to the latter is evident, but it does not seem that the crab is likely to be in grave peril when it has not its Actinia, Many of the Melias brought back by explorers have no anemones, and we may believe that the presence of this living tool is not yet a vital necessity to the species of this curious genus. But this is not true of the ants which use their larva? as needles. Here the singular habit is innate, specific. It was probably acquired through intelligent acts, but, with the species which practise it, it now belongs entirely to the domain of instinct. And so we always return to the fact which dominates the psychological history of the articulates, namely, the transformation of intelligent acts into instinctive acts. The following considerations formulated by Berg-son admirably apply to this group :
Among animals, invention is never more than a variation on the theme of routine. Locked up within the habits of the species, the animal succeeds, no doubt, in broadening these by its individual initiative; but it escapes from automatism only for an instant, just long enough to create a new automatism; the gates of its prison close as soon as opened; dragging on its chain, it merely succeeds in lengthening it. With man consciousness breaks the chain.