XII. 

 HEREDITARY INEFFICIENCY. 



THIS world is not, on the whole, a hard world to live 

 in if one have the knack of making the proper conces- 

 sions. Hosts of animals, plants, and 

 The art of living. , , , . . , , , 



men have acquired this knack, and they 



and their descendants are able to hold their own in the 

 pressure of the struggle for existence. This pressure 

 brings about the persistence of the obedient, those whose 

 activities accord with the demands of their environment. 

 This persistence of the adaptive is known as the survival 

 of the fittest, which has through the ages been the chief 

 element of organic progress. Among men there have 

 always been those to whom the art of living was im- 

 possible. This has been the case under ordinary con- 

 ditions as well as under extraordinary ones. It must be 

 the case with some under any conceivable environment 

 or any circumstances of life. Some variations must 

 tend in the direction of incapacity. This incapacity of 

 one generation, if inborn and not induced by disease or 

 malnutrition, may be handed down by the law of heredity 

 to the next. 



In one way or another, in time, most of the incapa- 

 bles are eliminated by the process of natural selection. 

 But not all of them. Our social system is bound too 

 closely. Hereditary incapacity of the few has been in 

 all ages a burden on the many who could take care of 



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