6 Astronomy and Geology compared. PT. i. 



former creations. Geology has its being only in the 

 past, but Astronomy exists in the present. The vast 

 orbs which, in companionship with ourselves, roll 

 round the sun; that mighty luminary itself, the 

 centre and life of our system, exists now as surely as 

 we do ourselves, and will exist in after ages. The 

 dominion of Geology is restricted to the past ; 

 Astronomy is with us in the present, and will be 

 with us in the future. 



Another and a very important distinction between 

 these two sciences is a difference in the nature of the 

 proofs upon which they rest. There are three great 

 methods of inquiry by which we advance to the 

 attainment of scientific truth, three roads on which 

 the human mind travels in the acquisition of 

 knowledge. The first of these is the study of the 

 Abstract and Exact Sciences of Arithmetic and of 

 pure Mathematics, whether in the form of Geometry 

 or of algebraical analysis, and their subsequent 

 application to the solution of all those problems 

 capable of being submitted to them. The second 

 is the accumulation, observation, comparison, and 

 analysis of the Evidence of Facts, and the de- 

 duction from them of uniform laws of nature and 

 fixed relations of cause and effect. The third is 



