340 THE ASCENT OF MAN 



ures, of all the mothers who fell short of completing 

 the process to the last detail. And hence, by the 

 law of the Survival of the Fittest, Altruism, which 

 at this stage means good-motherism, is forced upon 

 the world. 



This consummation reached, the foundations of 

 the human world are finished. Nothing foreign 

 remains to be added. All that need happen hence- 

 forth is that the Struggle for the Life of Others 

 should work out its destiny. To follow out the 

 gains of Reproduction from this point would be to 

 write the story of the nations, the history of civiliza- 

 tion, the progress of Social Evolution. The key 

 to all these processes is here. There is no intelli- 

 gible account of the world which is not founded 

 on the realization of the place of this factor in 

 development. Sociology, practically, can only beat 

 the air, can make no step forward as a science, 

 until it recognizes this basis in biology. It is the 

 failure, not so much to recognize the supremacy 

 of this second factor, but to see that there is any 

 second factor at all, that has vitiated almost every 

 attempt to construct a symmetrical social philosophy. 

 It has long, indeed, been perceived that society is 

 an organism, and an organism which has grown 

 by natural growth like a tree. But the tree to 

 which it is usually likened is such a tree as never 



