I 



NATURAL SELECTION 153 



heredity, needing also, however, for its motion an 

 initial force, that of energy. 



Well, then, in this tout ensemble of evolution, we 

 will call one of the parts which go to form the 

 system the struggle for life. 



The progress of mechanical industry allows the 

 watchmaker to perfect and adjust the system of 

 connections, and to suppress or substitute one part 

 for another more simple, lighter, and more precise. 



In the system of evolution something similar 

 may occur. Whilst the animal world cannot 

 differentiate its psychic element sufficiently for man 

 to make himself intelligent, this part of the con- 

 nection which we have agreed to call struggle for 

 life works in the system of evolution ; but when 

 humanity becomes intelligent and begins to practise 

 artificial selection, as horticulturists and cattle- 

 breeders have done for some time past, even before 

 Darwin came upon natural selection, mistakes are 

 no longer possible, since it is easy to understand 

 that natural and artificial selection are the same 

 part of the connection taking part in evolution : 

 the one, coarse, brutal, and unconscious, peculiar 

 only to the brute; the other, the same part 

 polished by the work of the intelligence, that 

 knows how to render it more precise and delicate. 



The important thing, then, in sociology is not the 

 struggle for life, but, on the contrary, natural 



