1 859.] LYELL'S CRITICISMS. 211 



many whole classes of facts, which, if I am in my senses, it 

 seems to explain. As far as I understand your remarks and 

 illustrations, you doubt the possibility of gradations of intel- 

 lectual powers. Now, it seems to me, looking to existing 

 animals alone, that we have a very fine gradation in the intel- 

 lectual powers of the Vertebrata, with one rather wide gap (not 

 half so wide as in many cases of corporeal structure), between 

 say a Hottentot and an Ourang, even if civilised as much 

 mentally as the dog has been from the wolf. I suppose that 

 you do not doubt that the intellectual powers are as important 

 for the welfare of each being as corporeal structure ; if so, I 

 can see no difficulty in the most intellectual individuals of a 

 species being continually selected ; and the intellect of the 

 new species thus improved, aided probably by effects of 

 inherited mental exercise. I look at this process as now 

 going on with the races of man ; the less intellectual races 

 being exterminated. But there is not space to discuss this 

 point. If I understand you, the turning-point in our difference 

 must be, that you think it impossible that the intellectual 

 powers of a species should be much improved by the con- 

 tinued natural selection of the most intellectual individuals. 

 To show how minds graduate, just reflect how impossible 

 every one has yet found it, to define the difference in mind 

 of man and the lower animals ; the latter seem to have the 

 very same attributes in a much lower stage of perfection than 

 the lowest savage. I would give absolutely nothing for the 

 theory of Natural Selection, if it requires miraculous additions 

 at any one stage of descent. I think Embryology, Homo- 

 logy, Classification, &c. &c, show us that all vertebrata have 

 descended from one parent ; how that parent appeared we 

 know not. If you admit in ever so little a degree, the 

 explanation which I have given of Embryology, Homology 

 and Classification, you will find it difficult to say : thus far 

 the explanation holds good, but no further; here we must 

 call in "the addition of new creative forces." I think you 



P 2 



