Mechanism, Vitalism, and Teleology 371 



man even to conceive such an idea, or to hope that a Newton may one 

 day arise to make even the production of a blade of grass compre- 

 hensible, according to natural laws ordained by no intention." 



Haeckel and other pure mechanists have hailed Darwin as Kant's 

 impossible Newton of the living world and his theory of "natural 

 selection" as the purely mechanical principle which accounts for the 

 adaptations of organisms. ... In the light of Darwin's theory 

 we see that adaptations are the results of natural causes: the causal 

 mechanism applies to all the fitnesses of nature as well as to other 

 phenomena; but back of all mechanism, or running through all 

 mechanism, is teleology or purpose. 



From the standpoint of science and philosophy the origin of this 

 order and mechanism is the great secret of the universe. Science 

 deals only with mechanisms, and a purely scientific explanation must 

 be mechanistic, but there is no mechanical explanation for the ulti- 

 mate mechanism of the universe; mechanism cannot explain itself. 

 The mechanism of a locomotive will explain what it does, but it will 

 not explain its origin nor the purpose which it subserves. The organi- 

 zation of an animal or plant or egg is said to explain what it does, 

 but it will not explain the teleological nature of that organization. 



Biologists no longer think of any adaptation as having been directly 

 created for the purpose which it now serves but rather as having been 

 slowly developed in the course of evolution. Nevertheless, in tracing 

 an adaptation to its sources we do no more than transfer the origin 

 of fitness to earlier causes. We may explain the fitness of the eye as 

 due to its ontogenetic development, and this as due to heredity and 

 environment, but this does not explain how the potentialities of the 

 eye came to be in the germ-plasm. We have merely shifted the problem 

 to an earlier stage. And the same is true of the evolution of eyes: 

 our explanation of the origin of eyes may be that they are due to 

 mutation and natural selection, or to the inherited effects of use and 

 disuse: but in either case we do not explain the fact that eyes were 

 potentially present in these causes. We have merely shifted the prob- 

 lem from the fitness of results to the fitness of the causes of those 

 results: and in spite of Darwin and his great theory, it is still true 

 that no Newton has yet arisen "to make even the production of a 

 blade of grass comprehensible, according to natural laws ordained 

 by no intention." 1 



In two recent books of great philosophical and scientific 

 value, Henderson has shown that very many elements of the 



'Conklin, "Direction of Human Evolution," pp. 221-224. 



