LIMITS OF COMPARATIVE PSYCHOLOGY 729 



the pleasure, would explain the repetition as effect of some physi- 

 ological function of the satisfied instinct as effect, perhaps, 

 of heightened nerve-vigor. Whatever the condition of the repe- 

 tition, its result is, finally, a strengthening of the nerve-connec- 

 tion between the nerve-centre stimulated by the original environ- 

 ment and the nerve-centre whose excitation has brought about 

 the successful movement. In other words, the animal forms the 

 habit of reacting to the original environment by that movement 

 only which satisfies desire. The present question is, what sort 

 of consciousness accompanies the conduct, thus characterized, of 

 the animal which learns by experience? As parallel of the pre- 

 liminary random performances there is no need to assume any 

 save a sensational and a primitively affective consciousness ex- 

 cited by the animal's environment and by its own movements. 

 But what is the nature of the consciousness which accompanies the 

 immediately successful performance from which these instinct- 

 ive, random movements have dropped away, so that perception 

 of environment is, at once, followed by the acquired reaction? 

 Psychologists are agreed, in the first place, that these acquired 

 reactions, gained by repeated satisfactions, require imagination 

 on the part of the animals (and of the children) who learn them. 

 The rat which unerringly makes the successively correct turnings 

 through the labyrinth, in which he at first ran about ineffectively, 

 certainly seems to be guided by an image of the food which he has 

 repeatedly found at its centre. (The possibility that the mere 

 smell of the food sets off purely motor reflexes, whose success is 

 due to habit that the rat, in other words, does not imagine the 

 food, but actually smells it is excluded by experimenting in a 

 fresh labyrinth, without food at the centre. In this case, the rat's 

 movement evidently is not initiated by an external stimulus.) 



The significance of imagination to animals which learn by ex- 

 perience is, indeed, admitted by practically all psychologists. 

 Thorndike alone minimizes its importance, but even Thorndike 

 holds that he has proved imagination in the mental life of his cats. 

 These animals, who had repeatedly heard him speak a sentence 

 and then had seen him rise and give them food, learned to climb 

 up for the food on hearing his voice that is, before they saw 

 or smelled the food. 1 Of course, it does not follow that these ani- 

 mals remember in the sense of referring experience to their own 



1 Animal Intelligence, p. 65. For confirmatory experiments, cf. Kinnaman's 

 accounts of experiments on monkeys (Amer. Jour, of Psychol. xm, 129); also 

 Hobhouse, op. cit., p. 229 et al.: " If the direct way into a room is barred, a dog 

 or cat will at once betake itself to any other route. . . . This adpption of alter- 

 natives suggests that their action is to be referred not to an impulse urging 

 them to move in a particular direction, but rather to a desire to be in a particu- 

 lar place." Hobhouse gives experimental evidence of the occurrence of these 

 images of places. 



