170 ORGANIC EVOLUTION 



yet there are disadvantages as well. By means of our well- 

 warmed houses we protect ourselves from rain and cold, and 

 thus save from death many delicate ones who would other- 

 wise perish. But by preserving these weaker ones we allow 

 them to hand down to the next generation their weak consti- 

 tution, and so the race will average less robust than it would 

 be if the weak ones had been allowed to succumb to the cold 

 and so had never had offspring. Similarly the physician 

 saves from death many a weakling whose children bring 

 down the average of physical efficiency in the next genera- 

 tion. Physical deterioration has resulted from the partial 

 elimination of natural selection. Invalids are rare among 

 the lower animals : they are rare among savage races. How 

 common they are among us ! The invention of spectacles 

 has allowed our eyes to deteriorate without putting us at a 

 serious disadvantage. The skill of the dentist has tended 

 toward unsound teeth for civilized man. Such instances 

 might be multiplied. 



One point here should be clearly seen. Natural selection 

 seeks the highest efficiency of the species as a whole, and to 

 this end sacrifices innumerable defective individuals, lest they 

 and their children bring down the average of efficiency. 

 We, on the other hand, seek the welfare of the individual 

 and preserve and cherish the weak, though we know that by 

 so doing we in the end decrease the vigor of the race. Be- 

 cause of our charitable and altruistic tendencies we preserve 

 also the intellectually and morally weak, and thus cause a 

 certain intellectual and moral deterioration in the race aver- 

 age. I believe this is very largely compensated for by other 

 considerations, yet the deterioration is no less real. 



A good illustration of the effect of natural selection in 



