8 GENETICS AND EUGENICS 



In geology, the work of Lyell had shown that the present 

 condition of the earth's crust had come about gradually 

 through the action of causes still at work. 



Accordingly in all the fundamental sciences which deal 

 with the inorganic world the reign of natural law was ac- 

 knowledged before the time of Darwin, and the principle of 

 miraculous change was no longer offered as an explanation of 

 existing conditions. 



But in the realm of living things it was in Darwin's time 

 very different. The animal kingdom was not supposed to 

 have grown, but to have been made outright. The higher 

 animals were not supposed to have originated from lower 

 ones but to have been made in the form in which they exist 

 today. It was Darwin's work which dispelled this outgrown 

 idea, and established the principle of evolution as an explana- 

 tion of the organic as well as of the inorganic world. In his 

 time the idea was so novel as applied to animals and plants 

 that it aroused the greatest opposition. But the idea was not 

 wholly new to human thought; in forms more or less fanciful 

 and incomplete it had been suggested in previous centuries 

 from the days of the early Greek philosophers on. ^ 



Darwin lived in a time peculiarly inhospitable to the idea 

 of organic evolution, partly because of theological, and partly 

 because of scientific dogma. Had the idea been brought for- 

 ward centuries before accompanied by proofs such as Darwin 

 advanced in its support, it undoubtedly would have met more 

 ready acceptance than it found in the last century. As it 

 was, Darwin had to make the discovery anew for himself, 

 largely unaided by his predecessors, who, though they had 

 formulated more or less clearly the same line of explanation 

 which he adopted, had failed to put it to the test of long- 

 continued and detailed observation and experiment, which 

 alone sufficed firmly to establish it. 



1 Professor H. F. Osborn ('94) has described in a most interesting book the 

 various foreshadowings of the idea of organic evolution which appear in the writings 

 of Darwin's predecessors, and the development of the idea in Darwin's own mind 

 as evidenced by his letters and other writings. One interested in the historical and 

 philosophical growth of the idea cannot do better than to consult Osborn's book. 



