4G2 PROCEEDINGS OF THILADELPPIIA MEETING. 



all time, had. its birth in these early papers of Dana, conmiencing as far 

 back as 1847, when he was but thirt3^-three years of age. If with Comte 

 we define a great life as one in which a noble idea conceived in youth is 

 persistently carried out and perfected to the end, then was Dana's indeed 

 a great life ; for this, the fundamental idea of geology, was clearly con- 

 ceived l)y him in early life and elaborated in all its details to the very 

 end. It was moreover a noble idea, for by it the science of geology was 

 vitalized into a higher life. Let me stop a moment to inforce this ])oint. 



Those who arc familiar with Comte's '' Positive Philosophy " will re- 

 member that in his " Hierarchy of the Sciences " he denies geology a 

 2:)lace. He does so on the ground that it is not an abstract science at all, 

 but is, like geography, only a field for the operation of all the sciences. 

 Every distinct science has its own fundamental idea and its own dis- 

 tinctive method. Thus mathematics has its own fundamental idea of 

 number and quantity and its own distinctive method of notation. Phys- 

 ics and chemistr}" their fundamental ideas of mechanical energy and 

 chemical affinity and their distinctive method of experiment. Biology 

 its characteristic idea of life and its distinctive method — " the method 

 of comparison." Sociolog}^ its characteristic idea of social organization 

 and its distinctive method — " the historic method." But according to 

 Comte geology has neither characteristic idea nor distinctive method of 

 its own. I have long ago* shown the mistakes of Comte in this regard. 

 Geology also has its own characteristic underlying idea and tliat the 

 grandest of all, namely, that oi evoUdion of the earth thronf/Ji all time ; and 

 its own distinctive method, the evolution method or comparison in Ww 

 evolution series. The idea of evolution was not yet clearly grasped by 

 science at that time, otlicrwise Comte would have seen that his historic 

 method is nauglit else than the evolution method importcid from geology 

 into sociology. 



Now this fundamental idea of geology and this distinctive method, 

 although indeed dimly seen by previous thinkers and expressed by pre- 

 vious philosophical writers, especially by Whewell in his " Philosophy 

 of the Inductive Sciences," had not become a vitalizing idea and a work- 

 ing method until Dana. This was the underlying idea and this the 

 working method of all his work, and they were both finally embodied in 

 that really wonderful bo(jk, his " Manual of Geology." I regard Dana's 

 work as forming a distinct and very important epoch in the history of 

 geological science. Modern geology has two important epochs — that of 

 I^yell by the introduction of the study of " causes now in operation " as 

 the only sound basis of induction, and that of Dana by the introduction 

 of the idea of the development of the earth as a whole through all geo- 



* Comte's Classification of the Sciences, Berkeley Quarterly, April, 1881. 



