280 The Animal Mind 



for one purpose or another. The perception of objects 

 as distinct entities increases with the power of making defi- 

 nitely coordinated and adjusted motor responses to them. 

 That one important condition to the production of such re- 

 sponses lies in the possession of a grasping organ, a highly 

 movable member that can seize objects firmly and thus move 

 them about, is self-evident. The elephant and the monkey, 

 which. possess such organs, must have far more definite per- 

 ceptions of objects, as individual entities to be separated 

 from their backgrounds and used, than any other lower 

 animals. But to the acquisition of the most complicated and 

 perfect systems of motor reactions another factor contributes. 

 This factor is the movement idea. A movement idea is 

 the revival, through central excitation, of the sensations, 

 visual, tactile, kinaesthetic, originally produced by the per- 

 formance of the movement itself. And when such an idea 

 is attended to, when, in popular language, we think hard 

 enough of how the movement would "feel" and look if it 

 were performed, then, so close is the connection between 

 sensory and motor processes, the movement is instituted 

 afresh. The movement is willed by attending to the idea of 

 it. This is the familiar doctrine expounded by James in 

 Chapter XXVI of his " Psychology " (189). Recently it has 

 been pointed out that the "willing" of a movement by no 

 means always or even usually involves preliminary attention 

 to a movement idea (e.g. 445). This is undoubtedly true. 

 Nearly or quite all the movements executed by a man in the 

 ordinary course of a day are movements that he has made 

 many, many times before. And movements that have been 

 repeatedly made come to be made in response to stimuli 

 that through association have been substituted for the origi- 

 nal processes inducing movement. When I see my handker- 

 chief on the floor I do not need to think beforehand of what 



