A CENTURY OF aEOLOGY/ 



By Prof. Josp:ph lk Conte/ 



Geology is one of the youngest of the sciences. It may almost be 

 said to have been born of the present century. It is true that knowl- 

 edge concerning the structure of the earth had been accumulating ever 

 since the time of the Greeks and Romans; it is true that these materials 

 became more abundant and were better organized in the eighteenth 

 century; but this knowledge had not yet taken form as a distinct 

 branch of science until about the end of that century. There are two 

 distinctive marks of scientific as compared with popular knowledge: 

 First, that its fundamental idea is clearly conceived; and, second, that 

 its method is distinctly inductive. 



1. Fandanientalidea. — The fundamental idea underlying geological 

 thought is the history of the earth. Now, until the beginning of the 

 present centur}^ the earth was not supposed to have any history. It 

 was supposed to have been made at once, out of hand, about six thou- 

 sand 3'ears ago, and to have remained substantially unchanged ever 

 since as the necessary theater of human history. Changes were known 

 to have taken place, and in less degree to be still taking place, but these 

 were not supposed to follow any law such as is necessary to constitute 

 a history, and thus to constitute a science distinct from geography. 

 Bufi'on, about the middle of the last century, did indeed bring out 

 dimly the idea of an abyss of time, preceding the advent of man, in 

 which the earth was inhabited by animals and plants wholly different 

 from those of the present day, but he was compelled by the priests of 

 the Sorbonne to retract these supposed irreligious views. So tardily 

 was the fundamental idea of geology clearly conceived that Comte, the 

 great originator of scientific philosophy, in his classification of the 

 sciences in 1820, denied a place to geology because, according to him, 

 it was not a distinct science at all, but only a field for the application of 

 all the sciences. It is evident that he did not perceive the fundamental 



1 Reprinted, by permission, from Appleton's Popular Science Monthly, ^'()I. T.YI, 

 February and March, 1900. 

 '' In this article I have attempted to j^i ve only the development of geological tlioujjht. 



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