150 SOCIAL HEREDITY AND SOCIAL EVOLUTION 



pose, but where blood relationship was no longer 

 apparent. Whether these tribes have resulted from 

 growth or secondary union we cannot say. It is 

 more natural to think of them as the result of growth, 

 for by simple reproduction groups of hundreds or 

 thousands of men would be quickly produced, all 

 descended from the original stock, although all evi- 

 dence of close relationship would soon disappear. 

 Such a group would form a tribe. It is also con- 

 ceivable that different clans, belonging to entirely 

 different family groups, but located in each other's 

 vicinity, may have combined temporarily for the 

 purpose of repelling attacks of enemies or of mak- 

 ing mutual conquests. Such early unions may have 

 been temporary and, after the emergencies had 

 passed, the different clans probably as a rule sepa- 

 rated each to his own interests. Thus from the first, 

 warfare has been the great organizing force. Peace- 

 ful savage tribes have little organization and no 

 chieftains. The Eskimos are a peaceful race and 

 have no organizations. Warfare always demands 

 union and leadership, and this has been equally true 

 of primitive savage races and civilized man. 



But although these primitive organizations were 

 undoubtedly temporary, it is certainly a fact that 

 as the ages passed they became more and more per- 

 manent. Clans associating originally for mutual 

 defense or for mutual contests failed to separate 

 when the emergency was passed, and for a long time 

 remained united. In this way arose the larger tribes 

 and the early kingdoms, and by a constant combina- 

 tion the kingdoms increased in size to form the em- 

 pires. From this point the history of civilization 

 has been one of constant progression toward in- 



