APHORISMS AND REFLECTIONS 91 



not-living- world is concerned, uniformitarianism lies 

 there, not only in germ, but in blossom and fruit. 



If one asks how it is that Hutton was led to 

 entertain views so far in advance of those prevalent 

 in his time, in some respects ; while, in others, they 

 seem, almost curiously limited, the answer appears 

 to me to be plain. 



Hutton was in advance of the geological specula- 

 tion of his time, because, in the first place, he had 

 amassed a vast store of knowledge of the facts 

 of geology, gathered by personal observation in 

 travels of considerable extent ; and because, in the 

 second place, he was thoroughly trained in the 

 physical and chemical science of his day, and thus 

 possessed, as much as any one in his time could 

 possess it, the knowledge which is requisite for the 

 just interpretation of geological phenomena, and the 

 habit of thought which fits a man for scientific 

 inquiry. 



It is to this thorough scientific trammg that I 

 ascribe Hutton's steady and persistent refusal to 

 look to other causes than those now in operation 

 for the explanation of geological phenomena. 



The internal heat of the earth, the elevation and 

 depression of its crust, its belchings forth of vapours, 

 ashes, and lava, are its activities, in as strict a sense 

 as are warmth and the movements and products of 

 respiration the activities of an animal. The pheno- 

 mena of the seasons, of the trade winds, of the Gulf- 

 stream, are as much the results of the reaction 

 between these inner activities and outward forces 

 as are the budding of the leaves in spring and their 

 falling in autumn the effects of the interaction 

 between the organisation of a plant and the solar 

 light and heat. And, as the study of the activities 

 of the living being is called its physiology, so are 

 these phenomena the subject-matter of an analogous 

 telluric physiology, to which we sometimes give the 

 name of meteorology, sometimes that of physical 

 geography, sometimes that of geology. Again, the 



