THE ORIGIN OF THE HUMAN SOUL 241 



enable the observer to distinguish between this deceptive sem- 

 blance of intelligence and that inherent rational power of 

 abstraction, classification, and inference which is the unique 

 prerogative of the human being. A genuine intelligence of this 

 sort need not be invoked to explain any of the phenomena of 

 brute psychology. All of them, from the highest to the lowest, 

 are explicable in terms of the sensitivo-nervous functions. To 

 illustrate the truth of this statement let us cite a few typical 

 examples of animal behavior, that are sometimes regarded as 

 manifestations of intelligent or rational consciousness on the 

 part of the brute. 



Animals, it is pointed out, learn by experience. The tiny 

 chick that has been stung by a wasp, for instance, learns to 

 avoid such noxious creatures for the future. This is, indeed, 

 "learning by experience." Obviously," however, it does not 

 consist in an inference of a new truth from an old truth. On 

 the contrary, it amounts to nothing more than a mere associa- 

 tion of imagery, formed in accordance with the law of con- 

 tiguity in time, sanctioned by the animal's sensual appetite, 

 and persistently conserved in its sentient memory. A bond of 

 association is formed between the visual image of the wasp 

 and the immediately ensuing sensation of pain. Thereafter 

 the wasp and the pain are associated in a single complex, 

 which the sensile memory of the animal permanently retains. 

 We are dealing with a mere association of contiguity, and 

 nothing further is required to explain the future avoidance 

 of wasps by the chick. The abilities acquired by animals 

 through the trial and error method are to be explained in the 

 same way. A horse confined within an enclosure, for example, 

 seeks egress to the fresh grass of the pasture. The fact that 

 repeated exits through the gate of the enclosure have associ- 

 ated the image of its own access to the pasture with the par- 

 ticular spot where the gate is located induces it to approach the 

 gate. Its quest, however, is balked by the fact that the gate is 

 closed and latched. Thereupon, it begins to chafe under the 

 urge of frustrated appetite. Certain actions ensue, some spon- 



