280 DOCTRINE OF EVOLUTION 



employ the methods of scientific common-sense which 

 only yield sure results? It is no more justifiable to 

 discard our hard-earned knowledge than it would be for 

 an advocate to undertake the conduct of a case in delib- 

 erate disregard of what he had learned of the law, or for 

 a surgeon to leave his knowledge at the door when he 

 entered the operating room. Too often we are bidden 

 to view the larger conceptions of nature and super- 

 nature as something outside the realm of ordered knowl- 

 edge; too frequently we are given statements upon 

 authority that takes no account of reason, and we are 

 asked to accept these views whether or not they accord 

 with the demonstrated facts of common-sense. But 

 those who have followed the present description of evo- 

 lution can readily recognize their obligation to use for the 

 further analysis of higher human life the means which 

 have given in that doctrine the most reasonable explana- 

 tion of the natural phenomena already investigated. 



I need hardly say that we now enter upon the most 

 difficult stage of our progress. The regions we have 

 traversed were more readily explored because they were 

 remote from the matters now before us ; even in the case 

 of man's mental and social evolution it was possible to 

 take a partially impersonal view of certain of the essen- 

 tial elements in human life, which we cannot do now. 

 For ethics and rehgion and philosophy are groups of ideas 

 that are familiar to us as the property of mankind alone. 

 Countless obstacles are in the way. Much mental inertia 

 must be overcome, for it is far easier to accept the aver- 

 age and traditional judgments of other men — to let well 

 enough alone — than it is to win our own way to the 

 heights from which we may survey knowledge more fully. 



