MENTAL EVOLUTION OF MAN 211 



ative psychology, which establishes the conclusion that 

 reason is the more complex term of a series to which 

 reflex action, instinct, and intelligence directly lead. 



Were w^e to study in detail the psychology of adult 

 human beings, we would find only more truly that 

 instinct and intelligence play a large part in our every- 

 day mental life, and more certainly that even the high- 

 est reasoning powers we possess are only more complex 

 in nature than the nervous processes of lower mammals 

 and invertebrates. Just as the nervous systems ad- 

 vance in physical or structural respects, so must their 

 activities become more and more complex until the 

 result is human faculty. 



We must now briefly consider what may be called 

 the '^ comparative anthropology " of mind which deals 

 with the various degrees of mental ability displayed by 

 different human races; this subject follows inevitably 

 upon the comparison of the human mind viewed as a 

 single type with the psj^chological processes of lower 

 animals. When we reviewed the diverse characteristics 

 of human races — the protrusion of the jaws, greater 

 or lesser stature, and the like — it appeared that so- 

 called '' lower " races could be distinguished which 

 differed from the '^ higher " races in the direction of the 

 apes ; the question immediately arises whether similar 

 distinctions and relations are discoverable on the basis 

 of mental traits. But in the present case there are not 

 so many well-substantiated differentia at the disposal 

 of the student, and it does not appear so clearly that 

 the '' higher " races are furthest from the lower pri- 



