MEDICAL ADVANCEMENT AS PRECLUDING HUMAN EVOLUTION 233 



Intelligence could make no stand against it. Physicians were impotent 

 in all attempts to check it. Every country lost many of her most intel- 

 ligent citizens. So long as human intelligence has not advanced to a 

 stage where it can produce, through medical and surgical aid, arbi- 

 trary immunity, the disease will run its natural course, when once it 

 takes possession of a race, and will eliminate the susceptible and ulti- 

 mately produce complete immunity. This will take place no matter 

 how intelligent the race may be providing there is as yet no known 

 means of checking the disease. If there happens to be correlation 

 between intelligence and susceptibility to any definite disease to which 

 a community is exposed the inevitable result is retrogression. This 

 is certainly the case in any tropical country where a new white popu- 

 lation and a native population reside. In so far as there is ignorance 

 of artificial immunity the majority infected by the jungle diseases are 

 the new comers and hence those of superior intelligence. 



In man and the higher animals the physical character that is best 

 correlated with intelligence is the size of the cerebral cortex. In man 

 the brain is almost the only character changing and developing. And 

 when we reach a stage in medical science when we are able to render 

 every individual immune through surgery and inoculation, and "by 

 means of the sum of human contrivances " ' advance, independently 

 of heredity, this will be more true. Yet it is doubtful whether even the 

 brain is developing in any degree rapidly enough to account for the 

 progress that is taking place. 



In human civilization each generation is working at a higher level 

 and with better tools which their predecessors have devised. The 

 product of this labor is the social environment. The essential thing is 

 that evolution has been transferred from the organism to the environ- 

 ment, and it is the environing social structure which persists. Progess 

 may be expressed, therefore, as a product, rather than the rise of average 

 intellectual capacity. This product is the mould in which mediocrity 

 is cast. Progress and education do not necessarily imply that the level 

 of intelligence is becoming higher but merely the level of acquisition. 



As a result of the development of medical science and surgery, by 



1 Ritchie, Darwinism and Politics. 



