32 THE METHODS AND 



preeminently among all the sciences, we are 

 looking for light on human destiny. To 

 pretend otherwise would be mere hypocrisy. 

 So while reserving the higher line of defence 

 I will reply that again and again in our 

 experimental work we come very near indeed 

 to human affairs. Sometimes this is obvious 

 enough. No practical dog-breeder or seeds- 

 man can see the results of Mendelian recom- 

 bination without perceiving that here is a bit 

 of knowledge he can immediately apply. No 

 sociologist can examine the pedigrees illus- 

 trating the simple descent of a deformity or 

 a congenital disease, and not see that the 

 new knowledge gives a solid basis for prac- 

 tical action by which the composition of a 

 race could be modified if society so chose. 

 More than this : we know for certain in one 

 case, from the work of Professor Biffen, that 

 the power to resist a disease caused by the 



