156 . PRIMEVAL MAN. 



dation." Yet nothing in the Natural History 

 of Man can be more certain than that both 

 morally, and intellectually, and physically he 

 can, and he often does, sink from a higher 

 to a lower level. This is true of Man both 

 collectively and individually — of men and of 

 societies of men. Some regions of the world 

 are strewn with the monuments of civilizations 

 which have passed away. Rude and barba- 

 rous tribes stare with wonder on the remains 

 of Temples, of which they cannot conceive 

 the purpose, and of Cities which are the dens 

 of beasts. It is not necessary to assume, as 

 it has sometimes been assumed, that there 

 is a law of decay affecting communities as 

 certain in its operation as the law which 

 operates on the individual frame. It is enough 



