446 Living in a World of Change 



We do not need to contemplate the gap that separates 

 us from the apes, then, except as we learn, from comparative 

 studies, to recognize the essentials, whether of resemblance 

 or of difference. For certain purposes comparisons are more 

 profitably made among wider ranges of types. For other 

 purposes we find it more profitable to compare identical 

 twins. But if a comparative study is to have value it must 

 be without prejudice. 



Evolution and Mechanism 



For the reasons already given, modern science cannot 

 employ a method that assumes personal entities as a basis of 

 understanding or interpreting observable phenomena. The 

 scientist may not say, however, that there is no controlling 

 purpose in the universe. All he can say is that it does not 

 help him to make the assumption, if he is to pursue further 

 the problem of how things work. The assumption of a con- 

 trolling purpose, or of a consciousness inside the mechanism 

 which he is studying, may be satisfactory for those who do 

 not care to search further; but for the scientist it is no 

 solution at all; it is not even the beginning of a search. He 

 feels that to say the blood distributes oxygen to the tissues 

 because it is its nature to do that, cheats him of a chance to 

 find out what particular connection there is between the 

 structure and the function. 



The scientist therefore insists upon the study of mech- 

 anism as a method of thought which embraces man and other 

 living things, and which applies to mental processes as well 

 as to chemical and physical. But this search for mechanism 

 has no relation whatever, either scientific or philosophical, 

 to " materialism " as this expression of reproach is commonly 

 used as somehow implying beastliness, or satisfaction in the 

 gross and sensual. Of all the discourses I ever heard the most 

 " materialistic," in this properly disparaged sense, came from 

 the mouth of a bishop of a certain Christian sect. The 

 bishop was celebrating Easter Sunday by elaborating on the 



