274 PROBLEMS OF HUMAN EVOLUTION 



much felt in either case for two or three generations. Optical 

 instruments may possibly improve more rapidly than average 

 eyesight deteriorates : there is, in fact, the race between the 

 softening of the environment on the one side and degeneration 

 on the other, and when the former wins, the latter is not likely 

 to make itself felt. Science may possibly, for a time, outstrip 

 deterioration. But the victory of science only brings nearer the 

 day of ultimate defeat, since the more rapidly the standard is 

 lowered for any organ, the greater the resultant instability : in 

 fact the more rapid the process of degeneration. 



There remain the other organs and qualities which I have 

 described as protected, because they are correlated with general 

 vigour. They have lasted during centuries of civilisation and 

 it might be thought that there was no need to feel any alarm 

 on their behalf. However, during the last few decades the 

 softening of the environment has been so very rapid that even 

 here the deterioration is likely to be appreciable though less 

 rapid than in the cases we have just considered. Medical 

 science seems likely to get an almost complete mastery of the 

 germs of zymotic disease, and hitherto these germs, allying them- 

 selves with some congenital defect, have caused an enormous 

 amount of elimination. If the germs are banished, the con- 

 genital defects will work unaided, that is, the standard of 

 physique will be lower. In addition to this, great efforts are 

 being made to banish the crises on which vigour depends. 

 Even those whose ordinary life is a comfortless desert, often 

 find themselves during sickness in an oasis of comfort. As time 

 goes on, this will be more and more the case, since science and 

 humanity forbid that it should be otherwise. 



Other Here again it may be said : what matter if the strength of 



races t h e barbarian has been lost ? The conditions of life are much 



criterion easier and so nobody wants it. This argument is highly 



plausible, but utterly unsound. History tells of numbers of 



races that have disappeared because they lost their vigour and 



consequently were conquered by others who, though less 



civilised, were harder and stronger. Altogether apart from 



such questions, what we may call an artificial vigour, due to 



