182 PHYSICAL BASIS OF CIVILIZATION 



institution of the home, all had their roots in the 

 physical defects alluded to in the first chapter. 



In the eighth chapter it was made clear how the 

 conditions mentioned in earlier chapters inevitably 

 produced a radical differentiation in habits and 

 character along the sex line. 



In all these eight chapters the argument was 

 limited to conditions existing before man had 

 learned to arm and warm himself artificially. In 

 the ninth chapter it was pointed out that the two 

 different types of race character mentioned in the 

 eighth are properly distinguished as the "true 

 hereditary" and "false exceptional"; that an era 

 of new conditions must have begun when man 

 armed himself artificially. In the antecedent period 

 only the rigorous natural selection of men of the 

 false type could have saved the race from extermina- 

 tion; in the subsequent era man's supremacy on 

 earth was so absolutely secure that the false type 

 found little opportunity for employing its special 

 destructive faculties, except in activities highly 

 injurious to the peace, welfare, and progress of the 

 race. It was shown that this circumstance led to 

 introracial warfare, to the first formation of groups 

 and hordes. 



In the tenth chapter attention was then called 

 to the true hereditary character of the human race 

 as a new factor in the universe and to its wonderful 

 achievements. It was pointed out how this new 

 factor ultimately has the power of turning the blind 



