XI .] GEOLOGICAL REFORM. 199 



As your attorney-general for the time being, I thought I 

 could not do better than get up the case with a view of advising 

 you. It is true that the charges brought forward by the other 

 side involve the consideration of matters quite foreign to the 

 pursuits with which I am ordinarily occupied ; but, in that 

 respect, I am only in the position which is, nine times out of 

 ten, occupied by counsel, who nevertheless contrive to gain their 

 causes, mainly by force of mother-wit and common sense, aided 

 by some training in other intellectual exercises. 



Nerved by such precedents, I proceed to put my pleading 

 before you. 



And the first question with which I propose to deal is, 

 What is it to which Sir W. Thomson refers when he 

 speaks of &quot; geological speculation &quot; and &quot; British popular 

 geology&quot;? 



I find three, more or less contradictory, systems of geological 

 thought, each of which might fairly enough claim these ap 

 pellations, standing side by side in Britain. I shall call one of 

 them CATASTROPHISM, another UNIFORMITARIANISM, the third 

 EVOLUTIONISM ; and I shall try briefly to sketch the characters 

 of each, that you may say whether the classification is, or is not, 

 exhaustive. 



By CATASTROPHISM, I mean any form of geological speculation 

 which, in order to account for the phaenomena of geology, 

 supposes the operation of forces different in their nature, or 

 immeasurably different in power, from those which we at present 

 see in action in the universe. 



The Mosaic cosmogony is, in this sense, catastrophic, because 

 it assumes the operation of extra-natural power. The doctrine 

 of violent upheavals, debacles, and cataclysms in general, is 

 catastrophic, so far as it assumes that these were brought about 

 by causes which have now no parallel. There was a time when 

 catastrophism might, pre-eminently, have claimed the title of 

 &quot; British popular geology ; &quot; and assuredly it has yet many 

 adherents, and reckons among its supporters some of the most 

 honoured members of this Society. 



