238 LAY SERMONS, ADDRESSES, AND REVIEWS, |xi 



name of meteorology, sometimes that of physical geo- 

 graphy, sometimes that of geology. Again, the earth 

 has a place in space and in time, and relations to other 

 bodies in both these respects, which constitute its distri- 

 bution. This subject is usually left to the astronomer ; 

 but a knowledge of its broad outlines seems to me to be 

 an essential constituent of the stock of geological ideas. 



All that can be ascertained concerning the structure, 

 succession of conditions, actions, and position in space of 

 the earth, is the matter of fact of its natural history. 

 But, as in biology, there remains the matter of reasoning 

 from these facts to their causes, which is just as much 

 science as the other, and indeed more ; and this consti- 

 tutes geological aetiology. 



Having regard to this general scheme of geological 

 knowledge and thought, it is obvious that geological 

 speculation may be, so to speak, anatomical and develop- 

 mental speculation, so far as it relates to points of strati- 

 graphical arrangement which are out of reach of direct 

 observation ; or, it may be physiological speculation, so 

 far as it relates to undetermined problems relative to the 

 activities of the earth ; or, it may be distributional specu- 

 lation, if it deals with modifications of the earth's place 

 in space ; or, finally, it will be ^etiological speculation, if 

 it attempts to deduce the history of the world, as a 

 whole, from the known properties of the matter of the 

 earth, in the conditions in which the earth has been placed. 

 For the purposes of the present discourse I may take 

 this last to be what is meant by " geological speculation." 

 Now uniformitarianism, as we have seen, tends to 

 ignore geological speculation in this sense altogether. 



The one point the catastrophists and the uniformi- 

 tarians agreed upon, when this Society was founded, was 

 to ignore it. And you will find, if you ]ook back into 

 our records,. that our revered fathers in geology plumed 



