50 ANIMAL INTELLIGENCE 



subject has been advanced by studies on a lower plane 

 and by the process of comparison? Anatomy and 

 mammalian embryology would scarcely be worthy of 

 the name of sciences to-day but for studies conducted 

 on simpler forms. Do not psychologists sometimes 

 forget, as anatomists long did, that the human is 

 scarcely to be comprehended apart from the study of 

 simpler creatures ? Should we not look at psychology 

 as the naturalist now does at zoology, and endeavour to 

 discover the various grades in psychic processes, if such 

 there be, and it is only, so far as I can see, by com- 

 parative investigation that their existence or non- 

 existence can be established. 



To do such work at its best requires a knowledge of 

 both biology and psychology, and an intimate acquaint- 

 ance with the ways of animals. Closet lucubrations 

 cannot be expected of themselves to advance com- 

 parative psychology very much. 



Might not human psychology be made more objective 

 still, and is not the amount of wheat garnered much 

 out of proportion to the quantity of sheaves brought to 

 the thresher ? Has individual psychology received the 

 attention it deserves ? Might not the inductive method 

 be more fully applied to psychology ? I have long been 

 convinced that differences for races and for individuals 

 have been insufficiently recognised in physiology, and 

 at last there seems to be a reaction against the former 

 reckless leaps from frog or rabbit to man. 



The physiologist cannot, however, afford to ignore 

 the frog or the rabbit even when his goal is man ; nor, 

 f I may venture to express an opinion, can the psy- 

 chologist do so either without some loss possibly 

 great loss to his subject. 



I hope to see published, in the next few years, 

 detailed studies on many individual human beings of 

 both sexes, and also on individual animals. We must 



