258 Animal Intelligence 



are the sole laws of modifiability, insist that the thought of 

 an act will produce that act only if the act has been con- 

 nected with that thought (and without resulting discomfort) 

 in the animal's past. 



It seems plausible that there should be a peculiar bond 

 between the thought of a response and the response. The 

 plausibility is due to two reasons, one of which is sound but 

 inadequate, the other being, in my opinion, entirely un- 

 sound. The first reason is that, as a mere matter of fact, 

 the thought of a response does so often produce it. The 

 second is that an idea of a response seems a natural and 

 sufficient cause for it to appear. The first reason is inade- 

 quate to justify any law of the production of a response by 

 its image or other representative, since evidence can be 

 found to show that when a response is produced by an idea 

 of it, it has been already bound to that idea by repetition or 

 satisfaction. The second reason is unsound because, even 

 if responses are brought to pass occasionally by their 

 images, that is surely an extremely rare and unnatural 

 method. 



It is certain that in at least nine cases out of ten a re- 

 sponse is produced, not by an image or other representation 

 of it, but by a situation nowise like it or any of its accesso- 

 ries. Hunger and the perception of edible objects, far out- 

 weigh ideas of grasping, biting and swallowing, as causes 

 of the eating done in the world. Objects sensed, not im- 

 ages of eye-movements, cause a similar overwhelming ma- 

 jority of the eye's responses. We walk, reach and grasp 

 on most occasions, not because of anticipatory images of 

 how it will feel to do so or verbal descriptions to ourselves 

 of what we are to do, but because we are stimulated by the 

 perception of some object. 



It is also certain that the idea of a response may be im- 



