SCIENTIFIC THOUGHT 9 



as Huxley said of Paley. But let that pass ; what 

 clearly emerges from the controversy is that a 

 theory in its essence quite undistinguishable from 

 what we call evolution, has been under discussion 

 ever since the time of St. Augustine amongst 

 Catholic theologians. And to turn to other people ; 

 of course Erasmus Darwin, Lamarck, and Cham- 

 bers in his Vestiges of Creation put forward trans- 

 formist views, though without exciting any very 

 great interest, certainly without provoking any 

 very active controversy. 



How was it then that Darwin's work aroused 

 the storm which it did ? This is a point which we 

 may well consider, since there are important 

 lessons to be learned from it. In the first place the 

 book arrived at what the trite phrase calls the 

 " psychological moment." Scientific opinion, more 

 or less prepared by previous writings, was like a 

 salt in strong solution. Darwin's book was the 

 added crystal which caused the solidification of 

 the whole. But while this is so, the main cause of 

 the success of the book was its own excellence ; 

 the careful collection of facts ; the patiently elab- 

 orated argument ; its modest restrained presenta- 

 tion ; and, above all, the production for the first 

 time of a theory which purported to explain, and 

 did in large measure explain, how that transform- 

 ism, in which many had believed, perhaps in a 

 somewhat indefinite manner, could be conceived 

 to have come about. In addition to these reasons 

 there is a third which must never be left out of 

 consideration. The book became a party cry. This 

 most unfortunate circumstance was, I at once and 



