VI 



THE BEGINNINGS OF INTELLIGENCE 



"^TOTHING shews more the force of habit in 

 -'■ ^ reconciling us to any phenomenon, than this, 

 that men are not astonish'd at the operations of 

 their own reason, at the same time, that they ad- 

 mire the instinct of animals, and find a difficulty in 

 explaining it, merely because it can not be reduc'd 

 to the very same principles. To consider the matter 

 aright, reason is nothing but a wonderful and un- 

 intelligible instinct in our souls, which carries us 

 along a train of ideas, and endows them with par- 

 ticular qualities, according to their particular situa- 

 tions and relations. — ^David Hume, Treatise on 

 Human Nature. 



We all have a certain curiosity regarding the evo- 

 lutionary history of our various powers and attri- 

 butes, but from many points of view an unusual 

 interest attaches to the first development of intelli- 

 gence. The word intelligence is used in a variety of 

 senses by writers on comparative psychology, and 

 any discussion of the origin of intelligence would 

 be fruitless unless the meaning in which the term 

 is employed be understood. One of the foremost 



