1 82 The Founders of Geology LECT. 



still more elevated, huge fragments of rock may have been 

 carried to a great distance ; and it is not wonderful if 

 these same masses, greatly diminished in size, and reduced 

 to gravel or sand, have reached the shores or even the 

 bottom of the ocean." 1 Here the former conception of 

 the greater extension of the glaciers was foreshadowed as 

 a possible or even probable event in geological history. 

 Yet for half a century or more after Playfair's time, men 

 were still speculating on the probability of the transport 

 of the erratics by floating icebergs during a submergence 

 of Central Europe under the sea, an hypothesis for which 

 there was not a particle of evidence. No geologist now 

 questions the truth of Playfair's suggestion. 



In the whole of Hutton's doctrine he rigorously 

 guarded himself against the admission of any principle 

 which could not be founded on observation. He made no 

 assumptions. Every step in his deductions was based 

 upon actual fact, and the facts were so arranged as to 

 yield naturally and inevitably the conclusion which he 

 drew from them. Let me quote from the conclusion of his 

 work a few sentences in illustration of these statements. 

 In the interpretation of nature, he remarks, "no powers 

 are to be employed that are not natural to the globe, no 

 action to be admitted of except those of which we know 

 the principle, and no extraordinary events to be alleged 

 in order to explain a common appearance. The powers of 

 nature are not to be employed in order to destroy the 

 very object of those powers ; we are not to make nature 

 act in violation to that order which we actually observe, 

 and in subversion of that end which is to be perceived in 



1 Illustrations, p. 388. 



