THE PHYSICAL EVOLUTION OF THE HUMAN SPECIES 



AND OF HUMAN EACES 



The teachings of science that relate to the origin and 

 history of the human species constitute for us the most 

 important part of the whole doctrine of organic evolu- 

 tion ; and now, having completely outlined this doc- 

 trine as a general one, we are brought to the point 

 where we must deal frankly and squarely with the 

 insistent questions arising on all sides as to the way 

 that mankind is involved in the vast mechanism of 

 nature's order. These questions have been ignored 

 heretofore, in order that the natural history of animals 

 in general might be discussed without any interference 

 on the part of purely human interest and concern. It 

 now becomes our privilege, and our duty as well, to 

 employ and apply the principles we have learned in 

 order to understand more completely the origin of the 

 human body as an organic type, the history of human 

 races, the development of human faculty and of social 

 institutions, and the evolution finally of even the high- 

 est elements of human life. These are scientific prob- 

 lems, and if we are to solve them we must employ 

 the now familiar methods of science which only yield 

 sure results. 



We must not underestimate the many difficulties 

 to be encountered, for the field before us is a vast 



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