DELAYED REACTION 13 



responses. But even under such conditions, one would still be 

 studying the association of stimulus and response. This would 

 remain true as long as it was the feeding and not the animal's 

 reactions that were delayed. On the other hand, if both the 

 feeding and the reactions were delayed after the stimulus had 

 been given, then if there were such states as ideas one would 

 expect them to function here. Furthermore the need for ideas 

 would increase with the number of different stimuli and reactions. 

 Just a word now concerning Thorndike's formula for the 

 study of imagery. The fact that he himself was unable to 

 carry out experiments in conformity with it, and that none 

 have been carried out since his attempt, does not speak very 

 well for the formula. I must confess my own failure as yet to 

 perfect a technique by which the formula might be applied to 

 animals. In order to associate A and B, it will be necessary 

 that they be followed by a reaction x. A, B and x are now asso- 

 ciated. B and C may now be linked together through a second 

 reaction y. Even granting the ideational character of reactions 

 carried out according to the formula, one would have to know 

 the following facts . concerning the above test: (i) Did the 

 animal discriminate between A and B, between B and C, and 

 between A and C? If the first and second discriminations were 

 not made, A and B or C would have been directly associated 

 through x or y. If A and C were not discriminated, the asso- 

 ciation B-C would have been useless. Difficulties such as these 

 lead me to believe that the goal aimed at is unattainable. In 

 fact, Thorndike states that the formula is valid only when B 

 arouses no impulse to activity; this is the essential weakness 

 of the formula, for one can never be certain of the absence of 

 these intervening mediating motor tendencies. In fact their 

 presence is extremely probable. It cannot be too often reiter- 

 ated that structural psychology has no place in the study of 

 animal behavior. One must speak in terms of function. It is 

 impossible to tell whether an image is present or not. The 

 most that one can ever say is that some process other than 

 overt motor activity is present which functions as an image 

 might in human consciousness. This amounts to an accept- 

 ance of Hobhouse's statement (although I do not feel that he 

 always limits himself to this) that the ideas we deal with are 



