158 PHYSICAL BASIS OF CIVILIZATION 



If to this account of the origin of introracial war- 

 fare and of hordes and groups, however, it is ob- 

 jected that substantiation by observations and 

 experimental tests is impossible, then the reader 

 must be reminded that, as stated in the preface, this 

 cannot impair the value or validity of the conclusions 

 reached. "For rational minds do not for such 

 reason reject conclusions based on sound premises 

 explaining facts otherwise not rationally explicable. 

 If they did, then ' the theory of the infinity of space, ' 

 of 'the eternity of time,' of 'the indestructibility 

 of matter and force,' the belief that 'two parallel 

 lines never meet, no matter how far extended, ' 'the 

 nebular hypothesis, ' ' the universality of the laws 

 of nature,' and many other equally essential parts 

 of science and thought, would have to be rejected 

 along with the conclusion just reached in these 

 essays, for none of them can be verified by observa- 

 tions or experimental tests." And what are the 

 premises from which the above manner of accounting 

 for the origin of introracial warfare and the forma- 

 tion of hordes and groups follow as conclusions ? 



There is, firstly, the existence of the true and the 

 false human race characters. Of these two, the true 

 is by far the older type and the false a later variety. 

 Secondly, the natural selection of the false type dur- 

 ing the earliest period of brute-man's existence. 

 Thirdly, the law that the older hereditary tendencies 

 are always by far the more persistent, and that 

 reversions to the older type begin to increase when- 



