The Evidence of Mind 31 



associative memory," and therefore mind (429, p. 12). 

 The psychologist finds the term "associative memory" 

 hardly satisfactory, and objects to the confusion between 

 mental and physical concepts which renders it possible to 

 speak of a " mechanism" as forming an "elemental com- 

 ponent" in "psychic phenomena," but these points may be 

 passed over. The power to learn by individual experience 

 is the evidence which Romanes, Morgan, and Loeb will 

 accept as demonstrating the presence of mind in an animal. 

 Does the absence of proof that an animal learns by expe- 

 rience show that the animal is unconscious? Romanes is 

 careful to answer this question in the negative. " Because a 

 lowly organized animal," he says, "does not learn by its own 

 individual experience, we may not therefore conclude that in 

 performing its natural or ancestral adaptations to appro- 

 priate stimuli, consciousness, or the mind element, is 

 wholly absent; we can only say that this element, if 

 present, reveals no evidence of the fact" (641, p. 3). Loeb, 

 on the other hand, wrote as if absence of proof for conscious- 

 ness amounted to disproof, evidently relying on the principle 

 of parsimony, that no unnecessary assumptions should be 

 admitted. "Our criterion," he remarked, "puts an end to 

 the metaphysical ideas that all matter, and hence the whole 

 animal world, possesses consciousness" (429, p. 13). If 

 learning by experience be really a satisfactory proof of 

 mind, then its absence in certain animals would indeed 

 prevent the positive assertion that all animals are con- 

 scious ; but it could not abolish the possibility that they 

 might be. Such a possibility might, however, be of no 

 more scientific interest than any one of a million wild 

 possibilities that science cannot spare time to disprove. 

 But we shall find that learning by experience, taken by 

 itself, is too indefinite a concept to be of much service, and 



