128 SOCIAL HEREDITY AND SOCIAL EVOLUTION 



individuals who may be relied upon to combine with 

 him in accomplishing any plan of mutual utility. It 

 is human civilization rather than human intelli- 

 gence that makes the extraordinary contrast be- 

 tween animal and human life. 



It may be that the intelligence of man has de- 

 veloped since the time when he first appeared as 

 man. But it is also true that the difference in intel- 

 ligence between man of the twentieth century and 

 the man of primeval days is vastly less than it 

 seems to be. The chasm that separates twentieth 

 century civilization from that of four thousand 

 years before Christ is a vast one, but no such chasm 

 separates the mind of the twentieth century man 

 from that of his early progenitors. Indeed, some 

 insist that, within historical times, man has really 

 not advanced in intelligence. They tell us that the 

 Grreek, at the time of the glory of Greece, possessed 

 an intelligence equal to if not surpassing that of the 

 twentieth century. We need not here attempt to 

 decide whether or not this position is correct. Even 

 without admitting the claim, it is clear that the 

 great difference between the Caucasian of to-day 

 and the Greek of old is less in his innate capacity 

 than in the tools with which he has to work. If we 

 could give the Indian, from his infancy, all the facil- 

 ities of civilization, and if, on the other hand, the 

 Englishman should be given only the advantages 

 which the savage now has, the Indian would beyond 

 question accomplish vastly more than the English- 

 man, and would appear the more intelligent. 



The fact is that man is the only animal that has 

 built his own environment. Of all animals he is the 

 only one that has surrounded himself with artificial 



