98 ORGANIC EVOLUTION 



comparable to Darwin, who elucidated one modus 

 operandi of evolution. Meanwhile the biologists 

 have the advantage of the astronomers, and are 

 as surely entitled to assert the existence of a fact 

 which they can in large measure explain as are 

 the astronomers in asserting the existence of a 

 fact which they cannot explain. Frankly I will 

 venture to say that, in the light of modern know- 

 ledge, organic evolution is an obvious and self- 

 evident fact. To the astronomers, knowing what 

 they do, gravitation is an obvious and self-evident 

 fact. Yet it met, at its first announcement, with 

 opposition based on the superstition of the day. 

 Newton was accused of leading men to atheism 

 by substituting impersonal law for the personal 

 superintendence of the Deity. Freed from similar 

 superstitions, we are able to see that the theory 

 of organic evolution is as obvious and irresistible 

 an inference from the biological facts as is the 

 theory of universal gravitation from the astronomical 

 facts ; and ere we accept an inference so palpable, 

 we no more need a Darwin to tell us how evolution 

 is effected than the astronomer needs the explana- 

 tion of a Le Sage or any one else to justify him 

 in the belief that gravitation is a fact. Darwin's 

 explanation of organic evolution may be wrong ; 

 Le Sage's explanation of gravitation may be and 

 probably is wrong ; but men with eyes need no 

 theories of vision or solar physics to enable them 

 to see the sun at hiofh noon. To those who ask 

 them how they can possibly declare that they see 

 the sun, without the aid of any theory as to how 

 vision is effected, they may reply with the blind 



