172 THE DESCENT OF MAN 



that we know about savages, or may infer from their 

 v^ns and from old monuments, the history of which is 

 ^aite forgotten by the present inhabitants, show that from 

 the remotest times successful tribes have supplanted other 

 tribes. Eelics of extinct or forgotten tribes have been dis- 

 covered throughout the civilized regions of the earth, on the 

 wild plains of America, and on the isolated islands in 

 the Pacific Ocean. At the present day civilized nations 

 are everywhere supplanting barbarous nations, excepting 

 where the climate opposes a deadly barrier; and they suc- 

 ceed mainly, though not exclusively, through their arts, 

 which are the products of the intellect. It is, therefore, 

 highly probable that with mankind the intellectual faculties 

 have been mainly and gradually perfected through natural 

 selection; and this conclusion is sufficient for our purpose. 

 Undoubtedly it would be interesting to trace the develop- 

 ment of each separate faculty from the state in which it 

 exists in the lower animals to that in which it exists in man; 

 but neither my ability nor knowledge permits the attempt. 

 It deserves notice that, as soon as the progenitors of man 

 became social (and this probably occurred at a very early 

 period), the principle of imitation, and reason, and experi- 

 ence would have increased, and much modified the intel- 

 lectual powers in a way of which we see only traces in the 

 lower animals. Apes are much given to imitation, as are 

 the lowest savages; and the simple fact previously referred 

 to, that after a time no animal can be caught in the same 

 place by the same sort of trap, shows that animals learn by 

 experience, and imitate the caution of others. Now, if some 

 one man in a tribe, more sagacious than the others, invented 

 a new snare or weapouj or other means of attack or defence, 

 the plainest self-interest, without the assistance of much rea- 

 soning power, would prompt the other members to imitate 

 him; and all would thus profit. The habitual practice of 

 each new art must likewise in some slight degree strengthen 

 the intellect. If the new invention were an important one, 

 the tribe would increase in number, spread, and supplant 



