288 GEOLOGICAL CONTEMPORANEITY ix 



is to be regarded as an expression of the mode of 

 operation of natural forces, or whether it is simply 

 a statement of the manner in which a super- 

 natural power has thought fit to act, is a secondary 

 question, so long as the existence of the law and 

 the possibility of its discovery by the human 

 intellect are granted. But he must be a half- 

 hearted philosopher who, believing in that possi- 

 bility, and having watched the gigantic strides 

 of the biological sciences during the last twenty 

 years, doubts that science will sooner or later 

 make this further step, so as to become possessed 

 of the law of evolution of organic forms — of the 

 unvarying order of that great chain of causes and 

 effects of which all organic forms, ancient and 

 modern, are the links. And then, if ever, we 

 shall be able to begin to discuss, with profit, the 

 questions respecting the commencement of life, 

 and the nature of the successive populations of 

 the globe, which so many seem to think are 

 already answered. 



The preceding arguments make no particular 

 claim to novelty ; indeed they have been floating 

 more or less distinctly before the minds of geo- 

 logists for the last thirty years ; and if, at the 

 present time, it has seemed desirable to give them 

 more definite and systematic expression, it is be- 

 cause palaeontology is every day assuming a greater 

 importance, and now requires to rest on a basis 



