THE FUTURE OF THE LIVING WORLD. l8/ 



the practical extermination of all animals except such 

 as he especially preserves. 



His mastery over the higher vertebrates is so un- 

 bounded that he is the only one who has any possi- 

 bility of farther advance. With the lower animals, 

 his competition is not so severe, but, as we have 

 seen, these lower types have practically ended their 

 evolution in the distant past. 



To man alone, then, are open further possibilities 

 of higher development, and his development must 

 be wholly mental. His unique position in nature 

 comes upon us now with double significance. Even 

 more forcibly than ever do we see the significance of 

 the new law of love to which he is trying to adapt 

 his life. Remembering how lines of specialization 

 exhaust themselves, and how divergence of character 

 ends in extremes, we begin to get a grand conception 

 of the law of love which binds mankind into unity, 

 thus checking the development of castes and forcing 

 him to advance as a whole. The law of love is the 

 only law which could produce the highest mental 

 and moral development. 



