ORIENTATION OF MENTAL IMAGERY 291 



their architecture the summed-up profits of righteous 

 action. Their basic purposes, to that extent, have been 

 achieved, and from that level new constructive ends 

 may be attained by more direct, or economic, methods. 



V. The Evolution of Mental Imagery 



Animal life, as we have already seen, is a coopera- 

 tive and adaptive response to the outer world. But no 

 living thing responds to all its environments, nor can 

 it adapt its life to all the things to which it responds. 

 In this adaptive response to its environment, an animal 

 may move from place to place wherever protoplasm 

 may endure, or wherever it finds the physical condi- 

 tions essential to its activities. No animal can live, in 

 the past or in the future, or for one instant outside the 

 established sanctuary of physico-chemical conditions 

 essential to its being; nor, so far as we know, can it 

 consciously utilize the past to establish more profitable 

 relations with the future. 



Animal life, therefore, in the final analysis is a serial 

 response, or a moving picture if you will, of a particu- 

 lar part of the present external world of reality ex- 

 pressed in terms of protoplasmic activity. This animal 

 life, even though it be a reflection, or reaction, to some- 

 thing else, is itself a reality just as much as the world 

 external to it is a reality. It is, however, not the same 

 reality any more than the vibrating string is the same 

 thing as the moving bow, air waves, or the nervous 

 reactions they produce in man. Nevertheless each 

 reality may be interpreted in terms of the other. 



In man, a new vital factor has been introduced. In 

 addition to this older animal machinery of direct neu- 



