xv DABWIMSM APPLIED TO MAX 463 



here, and a reference to it has been introduced only to complete 

 the sketch of Mr. Darwin's view of the continuity and gradual 

 development of all human faculties from the lower animals up 

 to savages, and from savage up to civilised man. The point 

 to which I wish specially to call attention is, that to prove 

 continuity and the progressive development of the intellectual 

 and moral faculties from animals to man, is not the same as 

 proving that these faculties have been developed by natural 

 selection ; and this last is what Mr. Darwin has hardly 

 attempted, although to support his theory it was absolutely 

 essential to prove it. Because man's physical structure has been 

 developed from an animal form by natural selection, it does not 

 necessarily follow that his mental nature, even though developed 

 pari passu with it, has been developed by the same causes only. 

 To illustrate by a physical analogy. Upheaval and depres- 

 sion of land, combined with sub-aerial denudation by wind 

 and frost, rain and rivers, and marine denudation on coast- 

 lines, were long thought to account for all the modelling of 

 the earth's surface not directly due to volcanic action ; and 

 in the early editions of Ly ell's Principles of Geology these 

 are the sole causes appealed to. But when the action of 

 glaciers was studied and the recent occurrence of a glacial epoch 

 demonstrated as a fact, many phenomena — such as moraines 

 and other gravel deposits, boulder clay, erratic boulders, 

 grooved and rounded rocks, and Alpine lake basins — were seen 

 to be due to this altogether distinct cause. There was no breach 

 of continuity, no sudden catastrophe ; the cold period came 

 on and passed away in the most gradual manner, and its effects 

 often passed insensibly into those produced by denudation or 

 upheaval : yet none the less a new agency appeared at a 

 definite time, and new effects were produced which, though 

 continuous with preceding effects, were not due to the same 

 causes. It is not, therefore, to be assumed, without proof 

 or against independent evidence, that the later stages of an 

 apparently continuous development are necessarily due to the 

 same causes only as the earlier stages. Applying this argu- 

 ment to the case of man's intellectual and moral nature, I 

 propose to show that certain definite portions of it could not 

 have been developed by variation and natural selection alone, 

 and that, therefore, some other influence, law, or agency is 



