Page:Catholic Encyclopedia, volume 8.djvu/82

 INSTINCT

INSTINCT

the high grade of intelligence demanded at very low levels of animal life, and second, it assumes the in- heritance of acquired characteristics. Wundt rejects intelligence in the strict acceptation of the term as the source of animal instinct. His position is best stated in his own words: "We maj' reject at once as wholly untenable the hypothesis which derives animal in- stinct from an intelligence which, though not identical with that of man, is still, so to speak, of equal rank with it. At the same time we must admit that the adherents of an intellectual theory in a more general sense are right in ascriliing a large number of the manifestations of mental life in animals not, indeed, to intelligence, as the intelleetualists sensu strido do, but to individual experiences, the mechanism of which can only be explained in terms of association." (Op. cit., p. 389.) After dealing with another phase of this subject, he continues: "Only two hypotheses re- main, therefore, as really arguable. One of tliem makes instinctive action a mechanized intelligent action, which can be in whole or in part reduced to the level of the reflex; the other makes instinct a matter of inherited habit, gradually acquired and modified under the influence of the external environment in the course of numberless generations. There is obvi- ously no necessary antagonism between these two views. Instincts may be actions originally conscious, but now become mechanical, and they may he inher- ited habits." (Ibid., p. 393.) .\fter discussing human instincts and their relation to animal instincts, Wundt concludes: " External conditions of life and voluntary reactions upon them, then, are the two factors opera- tive in the evolution of instinct. But they operate in different degrees. The general development of men- tality is always tending to motlify instinct in some way or another. And so it comes about that of the two associated principles the first, — adaptation to environment, — predominates at the lower stages of life; the second, — voluntary activity, — at the higher. This is the great difference between the instincts of man and those of the animals. Human instincts are habits, acquired or inherited from previous genera- tions; animal instincts are purposive adaptations of voluntary action to the conditions of life. And a secontl difference follows from the first: that the vast majority of human instincts are acquired: while ani- mals . . . are restricted to connate instincts, with a very limited range of variation." (Ibid., 409.)

Romanes seeks to solve the problem of the origin of instinct by combining these two theories, accounting for the more rigid instincts of animals on the basis of natural selection and for the more plastic instincts by the inheritance of mechanized habits. He calls the former class of instincts primary and the latter sec- ondary. More recently, the theory of organic se- lection has been advanced. According to this theory purposive adaptations of all kinds, whether intelligent or organic, are called upon to supplement incomplete endowment, and thus to keep the species alive until variations are secured sufficient to make the instinct relatively independent.

It is evident from the definitions and theories given above that several distinct things are included under the term instinct. This finds expression in the divi- sion of instincts into primary and secondary siiggestcd by Homancs, and into connate ami acquired instincts (\Vundl). D.irwin emphasized the same fact when he claimed that many instincts may have arisen from habit, and thc-n adds: " but it would be a serious error to suppose that the greater number of instincts have been acquired by habit in one generation and then transmitted by inheritance to suceeeiling generations. It can be elearlv shown that the must wonderful in- stincts with which we are acquainted, namely, those of the hive-bee and of many ants, could not possibly have been acq\ured by habit." (Op, cit., vol. I, 321.) Formerly, instincts interested naturalists chiefly be-

cause they were regarded as so many illustrations of the intelligence of the Creator, antl, indeed, where it is a question of " primary ", or " inherited ", instincts — or instincts in " the strict sense of the term ", as Was- mann designates them — the problem of origin is simi- lar to that of the origin of anatomical characteristics. Evidently we shall have to account for such elaborate instincts as that which determines the conduct of the caterpillar or the emperor moth in building its cocoon along the same lines which we adopt in accounting for the origin of complicated anatomical structures. The intelligence tlisplayed far transcends that which could possibly have been possessed by such lowly creatures. The "secondary", or "acquired", in- stincts have a theoretical interest of an entirely dif- ferent character, arising out of the problems of the nature of animal intelhgence and the origin of man. Monists, and in general all those who accept the brute origin of man, seek to obliterate the essential difference between man and the animal; hence they ascribe to the animal an intelligence w'hich differs only in degree from that possessed by man. While at fir.st sight this would seem to lift the animal up to the plane of human life, what it does in reality is to lower man to the plane of brute life.

It may easily be demonstrated that many of the instincts in animals are capable of modification in the course of individual experience. Acts that are de- termined bj' a new element in the environment may be frequently repeated by a large number of the species; this repetition soon begets a habit which, to all in- tents and piu-poses, is identical with instinct. Such mechanized habits are, as we have seen, classified by some observers as instincts, and if such a habit be inherited, as some claim it may be, then no one would refuse to it the name of instinct. The real importance attacliing to this problem arises from the form of con- sciousness that is operative in building up such habits, or secondary instincts. Aristotle and the Schoolmen attributed these purposive adjustments to the appe- litus sensiiivus. They found no need of calUng into play any higlier faculty than sensory perceptions of particular objects and the recognition of their desira- bility or the reverse. This view is developed by Was- mann. It should be observed, however, that the term instincts as used by the Scholastics and by Wasmann refers not only to the neural mechanism or habit in the animal, but to the sensory powers which enable the animal to adjust its spontaneous activities to its surroundings. The term " was not taken merely as a constituent part of the sensitive power of cog- nition and appetite, but as the adaptive, natural disposition of animal sensation, which constitutes the vital principle that governs the spontaneous actions of the animal. . . . For apart from and beyond in- herited, instinctive knowledge, scholastic philosophy ascribed to the animal a sensile memory and a power of perfecting inborn instincts through sense experi- ence; it acknowledges in the animal not only com- plete hereditary talents for certain activities, but to a certain degree talent and ability acquired by sense experience and by practice." (Wasmann, op. cit., 138- 39.) Wuudt, as we have seen, denies to the animal intelligence of the same order as that possessed by man. A great deal of confusion has been imported into this subject by a loose and unjustifiable use of the terms reason and intelligence. To the super- ficial observer, of course, the jiower of sensory per- ception and association posses.scd by the animal resembles intelligence, but the terms have widely different signification. Intelligcnee in its lowest de- gree always implies as an es.sential cliaract eristic the power of abstraction and gencialization on which freedom of election rests, anil, until it is shown that animals possess such a power, it is unjustiliable to attribute such intelligence to them as the .school of naturalists do who ai)proach the subject with the