32 PHYSICAL BASIS OF CIVILIZATION 



To improve the quantity and quality of these 

 supplies and opportunities by the joint efforts of 

 many consciously devoted to such an end is utterly 

 unthinkable among brutes below man. 



In their case even the conditions precedent are 

 lacking on which the possibility of moral or social 

 motives depends, and intelligence makes progress 

 among them at so exceedingly slow a snail's pace 

 that races and even species are evolved, as the phrase 

 goes, flourish, and then disappear, without any per- 

 ceptible improvement in intellectual power being 

 apparent. Only by a perspective view across several 

 geologic ages can evidence of intellectual progress 

 among brutes below man be obtained. 



To return to the original line of argument : 



Two anatomical variations which, though great 

 and wonderful in their consequences, were so small 

 in their nature that it is almost thinkable that they 

 might have occurred in the transition from one gen- 

 eration to another, inevitably led to the erect atti- 

 tude, and to the disabilities, perils, and infirmities 

 enumerated in the first chapter. 



In subsequent chapters the task will be to prove 

 that from these as unavoidable consequences there 

 arose, in the order here stated, the enormous 

 increase in human intelligence, separation of the 

 sexes, the family, the dependence of woman, the 

 differentiation of the sexes in activities and character, 

 including the natural selection of the true hereditary 

 type of character for woman, and of the false or 



