THE WORLD INTO WHICH DARWIN WAS BORN 15 



The influence of these novel conceptions upon the 

 growth and spread of evolutionary ideas was far-reach- 

 ing and twofold. In the first place, the discovery of 

 a definite succession of nearly related organic forms, 

 following one another with evident closeness through 

 the various ages, inevitably suggested to every inquiring 

 observer the possibility of their direct descent one from 

 the other. In the second place, the discovery that 

 geological formations were not really separated each 

 from its predecessor by violent revolutions, but were the 

 result of gradual and ordinary changes, discredited the 

 old idea of frequent fresh creations after each cata- 

 strophe, and familiarised the minds of men of science 

 with the alternative notion of slow and natural evolu- 

 tionary processes. The past was seen to be in effect the 

 parent of the present; the present was recognised as 

 the child of the past. 



Current astronomical theories also pointed inevit- 

 ably in the same direction. Kant, whose supereminent 

 fame as a philosopher has almost overshadowed his just 

 claims as a profound thinker in physical science, had 

 already in the third quarter of the eighteenth century 

 arrived at his sublime nebular hypothesis, in which he 

 suggested the possible development of stars, suns, planets, 

 and satellites by the slow contraction of very diffuse and 

 incandescent haze-clouds. This magnificent cosmical con- 

 ception was seized and adapted by the genius of Laplace 

 in his celestial system, and made familiar through his 

 great work to thinking minds throughout the whole of 

 Europe. In England it was further modified and 

 remodelled by Sir William Herschel, whose period of 

 active investigation coincided in part with Charles 



