326 GEOLOGICAL REFOKM X 



or less vaguely, it is assuredly present in the 

 minds of most geologists. 



Such being the three phases of geological 

 speculation, we are now in position to inquire 

 which of these it is that Sir William Thomson 

 calls upon us to reform in the passages which I 

 have cited. 



It is obviously Uniformitarianism which the 

 distinguished physicist takes to be the representa- 

 tive of geological speculation in general. And 

 thus a first issue is raised, inasmuch as many 

 persons (and those not the least thoughtful among 

 the younger geologists) do not accept strict Uni- 

 formitarianism as the final form of geological 

 speculation. We should say, if Hutton and 

 Playfair declare the course of the world to have 

 been always the same, point out the fallacy by all 

 nxeans ; but, in so doing, do not imagine that 

 you are proving modern geology to be in opposi- 

 tion to natural philosophy. I do not suppose 

 that, at the present day, any geologist would be 

 found to maintain absolute Uniformitarianism, 

 to deny that the rapidity of the rotation of the 

 earth may be diminishing, that the sun Tnay be 

 waxing dim, or that the earth itself may be 

 cooling. Most of us, I suspect, are GalHos, " who 

 care for none of these things," being of opinion 

 that, true or fictitious, they have made no prac- 

 tical difference to the earth, during the period 



