The Evolution of Human Intellect 285 



which come in the mental life of man to outweigh and hide it. 

 But it is the basal fact. As we follow the development 

 of animals in time, we find the capacity to select impulses 

 growing. We find the associations thus made between 

 situation and act growing in number, being formed more 

 quickly, lasting longer and becoming more complex and 

 more delicate. The fish can learn to go to certain places, to 

 take certain paths, to bite at certain things and refuse others, 

 but not much more. It is an arduous proceeding for him 

 to learn to get out of a small pen by swimming up through 

 a hole in a screen. The monkey can learn to do all sorts 

 of things. It is a comparatively short and easy task for 

 him to learn to get into a box by unhooking a hook, pushing 

 a bar around and pulling out a plug. He learns quickly 

 to climb down to a certain place when he sees a letter T 

 on a card and to stay still when he sees a K. He performs 

 the proper acts nearly as well after 50 days as he did when 

 they were fresh in his mind. 



This growth in the number, speed of formation, perma- 

 nence, delicacy and complexity of associations possible for 

 an animal reaches its acme in the case of man. Even if we 

 leave out of question the power of reasoning, the possession 

 of a multitude of ideas and abstractions and the power of 

 control over impulses, purposive action, man is still the 

 intellectual leader of the animal kingdom by virtue of the 

 superior development in him of the power of forming as- 

 sociations between situations or sense-impressions and acts, 

 by virtue of the degree to which the mere learning by 

 selection possessed by all intelligent animals has advanced. 

 In man the type of intellect common to the animal kingdom 

 finds its fullest development, and with it is combined the 

 hitherto nonexistent power of thinking about things and 

 rationally directing action in accord with thought. 



