226 THE METHOD OF DARWIN. 



the principle of Natural Selection still de- 

 pends for its logical support upon that power of 

 deductive explanation which Darwin recognized 

 in it the day he read Malthus on Population. 

 It has penetrated every field of thought, but in 

 the field in which it first gathered strength it 

 is still without direct demonstration. It has 

 been made the basis for countless deductive 

 operations, but it leans for support on the very 

 structures thus erected. Writing to Bentham, 

 in 1863, concerning the proofs of natural selec- 

 tion and the descent of species, Darwin said, 

 "Belief in natural selection must at present be 

 grounded entirely on general considerations : 

 (i) on its being a vera causa from the struggle 

 for existence; ... (2) from the analogy of 

 change under domestication by man's selection; 

 (3) and chiefly from this view connecting 

 under an intelligible point of view a host of 

 facts. " 1 To Huxley he said, in December, 

 1860, "I can pretty plainly see that, if my 

 view is ever to be generally adopted, it will 

 be by young men growing up and replacing the 

 old workers, . . . and finding out that they can 

 group facts and search out new lines of inves- 

 tigation better on the notion of descent than on 

 that of creation." 2 



1 Life and Letters, Vol. II. p. 210. 2 Ibid., p. 147. 



