76 E. L. THORNDIKE. 



that their action is to be explained by the presence, through 

 association, of the idea B. But it is not impossible that 

 A was associated directly with the impulse to C, although that 

 impulse was removed from it by ten seconds of time. Such 

 an association is, it seems to me, highly improbable, unless the 

 neurosis of A, and with it the psychosis, continues until the im- 

 pulse to C appears. But if it does so continue during the ten 

 seconds, and thus get directly linked to C, we have exactly a 

 representation, an image, a memory, in the mind for eight of 

 those ten seconds. It does not help the deniers of images to 

 substitute an image of A for an image of B. Yet, unless they 

 do this they have to suppose that A comes and goes, and that 

 after ten seconds C comes, and, passing over the intervening 

 blank, willfully choses out A and associates itself with it. There 

 are some other considerations regarding the behavior of the 

 cats from the time the signal was given till they climbed up, 

 which may be omitted in the hope that it will soon be possible 

 to perform a decisive experiment. If an observer can make 



sure of the animal's attention to a sequence A B, where B 



does not arouse any impulse to an act, and then later get the 

 animal to associate B with C, leaving A out this time, he may 

 then, if A, when presented anew, arouses C, bid the deniers of 

 representations to forever hold their peace. 



Another reason for allowing animals representations and 

 images is found in the longer time taken to form the association 

 between the act of licking or scratching and the consequent 

 escape. If the associations in general were simply between 

 situation and impulse and act, one would suppose that the situa- 

 tion would be associated with the impulse to lick or scratch as 

 readily as with the impulse to turn a button or claw a string. 

 Such is not the case. By comparing the curves for Z on pages 

 22, 23 with the others one sees that for so simple an act it takes 

 a long time to form the association. This is not a final reason, 

 for lack of attention, a slight increase in the time taken to open 

 the door after the act was done, or an absence of preparation in 

 the nervous system for connections between these particular acts 

 and definite sense-impressions, may very well have been the 

 cause of the difficulty in forming the associations. Nor is it 



