Heredity and the Law of Evolution. 289 



manner which is peculiar and personal to himself, but we may 

 even affirm that the experience of countless generations slumbers 

 in him. So far is he from being homogeneous, that all the past 

 has contributed to his constituents. The present state of his 

 mechanism and his dynamism is the result of innumerable modi- 

 fications slowly accumulated ; and it may be affirmed that were 

 heredity to act alone, and were there no crossings, no spontaneous 

 variations, no psychical combinations or transformations, the secret 

 of which we cannot penetrate, the descendants would be necessarily 

 inclined to feel and to think as their ancestors. 



II. 



This hasty statement shows that heredity is one of the chief 

 factors of the law of evolution ; that by accumulating slight differ- 

 ences, heredity produces effects apparently out of all proportion 

 with the original causes. The living being is subject to the action 

 of its environment and modified by it ; nor does man, considered 

 as a thinking, sentient being, escape this law. Hence we see at 

 one time an amelioration, at another a deterioration of his faculties. 

 Chance, but especially education, may develop his intellect, his 

 character, his imagination, his sentiments; and since these ac- 

 quired modifications are sometimes transmitted by heredity, and, 

 in fact, taking everything into account, are mostly transmitted 

 we may say that the evolution of the psychical faculties is a law of 

 the intellectual world, and that the gain made by each generation 

 is to the advantage of those which follow. But where man has 

 discovered a law that is, an invariable rule which governs a 

 group of phenomena, if these phenomena are within his reach, or 

 come under his control, he can modify them, because he holds 

 in his hands the mainspring that moves and governs them. Thus 

 he is acquainted with the laws of heredity : he knows that they 

 exist and act, notwithstanding many exceptions which mask their 

 action. Can he turn them to account ? Can he employ them for 

 the perfecting of his species ? Let us put the question in clearer 

 and more explicit terms. The starting-point is a race of medium 

 intelligence, morality, and artistic and industrial capacity. The 

 goal is a race, quick of comprehension and expert in action, well- 

 disciplined, of gentle manners, and easily adapting itself to the 



