Although the observations on this point are not yet sufficiently varied and extended to enable us to speak of them as we should wish, it must be remarked that the cases cited are not alike, and that it would be illegitimate to reduce them all to one and the same psychological mechanism.
1. The case of insects is the most embarrassing. It is but candid to state a non liquet, since to attribute their achievements to unconscious numeration, or to some special equivalent instinct, is tantamount to saying nothing. Besides, we are not concerned with anything relating to instinct.
2. The case of the monkey and his congeners stands high in the scale: it is a form of concrete numeration which we shall meet again in children, and in the lowest representatives of humanity.
3. All the other cases resemble the alleged “arithmetic” of G. Leroy’s magpie and similar observations. I see here not a numeration, but a perception of plurality, which is something quite different. There are in the brain of the animal a number of co-existing perceptions. It knows if all are present, or if some are lacking; but a consciousness of difference between the entire group, and the diminished defective group, is not identical with the operation of counting. It is a preliminary state, an introduction, nothing more, and the animal does not pass beyond this stage, does not count in the exact sense of the word. We shall see further on that observations with young children furnish proofs in favor of this assertion, or at least show that it is not an unfounded presumption, but the most probable hypothesis.
We may now without further delay (while reserving the facts which are to be studied in the sequel to this chapter) attempt to fix the nature of the forms of abstraction, and of reasoning, accessible to the higher animal types.
1. The generic image results from a spontaneous fusion of images, produced by the repetition of similar, or very analogous, events. It consists in an almost passive process of assimilation; it is not intentional, and has for its subject only the crudest similarities. There is an accumulation, a summation of these resemblances; they predominate by force of numbers, for they are in the majority. Thus there is formed a solid nucleus which predominates in consciousness, an abstract appurtenant to all similar objects; the differences fall into oblivion. Huxley’s comparison of the composite photographs (above cited) renders it needless to dwell on this point. Their genesis depends on the one hand on experience; only events that are frequently repeated can be condensed into a generic image: on the other hand on the affective dispositions of the subject (pleasure, pain, etc.), on interest, and on practical utility, which render certain perceptions predominant. They require, accordingly, no great intellectual development for their formation, and there can be no doubt that they exist quite low down in the animal scale. The infant of four or five months very probably possesses a generic image of the human form and of some similar objects. It may be remarked, further, that this lower form of abstraction can occur also in the adult and cultivated man. If, e. g., we are suddenly transported into a country whose flora is totally unknown to us, the repetition of experiences suggests an unconscious condensation of similar plants; we classify them without knowing their names, without needing to do so, and without clearly apprehending their distinguishing characteristics, those namely which constitute the true abstract idea of the botanist.
In sum, the generic image comes half way between individual representation, and abstraction properly so called. It results almost exclusively from the faculty of apprehending resemblances. The rôle of dissociation is here extremely feeble. Everything takes place, as it were, in an automatic, mechanical fashion, in consequence of the unequal struggle set up in consciousness between the resemblances which are strengthened, and the differences, each of which remains isolated.
2. It has been said that the principal utility of abstraction is as an instrument in ratiocination. We may say the same of generic images. By their aid animals reason. This subject has given rise to extended discussion. Some writers resent the mere suggestion that ants, elephants, dogs, and monkeys, should be able to reason. Yet this resentment is based on nothing but the extremely broad and elastic signification of the word reasoning—an operation which admits of many degrees, from simple, empirical consecutiveness to the composite, quantitative reasoning of higher mathematics. It is forgotten that there are here, as for abstraction and for generalisation, embryonic forms—those, i. e., which we are now studying.
Taken in its broadest acceptation, reasoning is an operation of the mind which consists in passing from the known to the unknown; in passing from what is immediately given, to that which is simply suggested by association and experience. The logician will unquestionably find this formula too vague, but it must necessarily be so, in order to cover all cases.
Without pretending to any rigorous enumeration, beyond all criticism, we can, in intellectual development, distinguish the following phases in the ascending order: perceptions and images (memories) as point of departure; association by contiguity, association by similarity; then the advance from known to unknown, by reasoning from particular to particular, by analogical reasoning, and finally by the perfect forms of induction and deduction, with their logical periods. Have all these forms of reasoning a common substrate, a unity of composition? In other words, can they be reduced to a single type—of induction according to some, of deduction according to others? Although the supposition is extremely probable, it would not be profitable to discuss the question here. We must confine ourselves to the elementary forms which the logicians omit, or despise, for the most part, but which, to the psychologist, are intellectual processes as interesting as any others.