216 Letter from the Rev. W. D. Conybeare. 



yet friendly explanations of the opposing conclusions, to which 

 the varying views of the phenomena presented to different 

 minds give rise, can alone advance the progress of truth. It 

 is in this view that I myself regard the occasionally strong 

 expressions of Mr. Lyell, concerning the views of the school 

 of geologists which he opposes ; such for instance, as " They 

 are not content with disregarding the analogy of the present 

 course of nature when they speculate on the revolutions of 

 past times, but they often draw conclusions concerning the 

 former state of things directly the reverse of those to which a 

 fair induction from facts would infallibly lead them." When 

 I confess myself to have been led generally to adopt the opi- 

 nions of the school thus condemned, by the estimate which 

 the constitution of my own mind has forced me to form of all 

 the phaenomena which my own limited means of observation 

 have enabled me to investigate, I trust he will view with the 

 same indulgence my endeavours to retort, as well as I may, 

 the charge of false analogy and incorrect induction. 



If you, Mr. Editor, are therefore willing to open your pages 

 to the prosecution of the subject, I shall be happy to avail 

 myself of them, to endeavour to lay open my views, as to the 

 precise arrangement and classification of the geological facts 

 hitherto ascertained, which seem to me best calculated fairly 

 and fully to generalize them, and to dispose them in such an 

 order as to form the basis of a sound inductive process, — a task 

 as yet, I think, very imperfectly performed ; and an attempt 

 to execute which must, if conducted with the least ability, 

 point out the extent to which our present materials are defec- 

 tive, and suggest the inquiries requisite to supply those defi- 

 ciencies. It is thus that, in the words of Leonardo da Vinci, 

 " theory is the general, and experiments" (or in this case 

 observations) " the soldiers." Theory will always become ne- 

 cessary at a certain period in the progress of every science 

 "to generalize and consolidate" (as the writer who quotes 

 the above axiom in a late able and interesting Life of Galileo 

 well observes) " past observations, and thence to conjecture 

 the course of future observation most likely to reward his 

 assiduity." It is theory which indicates what experiments or 

 observations may justly deserve the title of luciferous in the 

 age to which I have alluded, — that of Kepler and Galileo. 

 Astronomy had exactly arrived at the stage of progress to re- 

 quire and repay this combination of theory and observation; 

 and the station which geology has now assumed, appears to 

 me in most of its circumstances very similar. The favourite 

 maxim of the Geological Society, as cited with apparent ap- 

 probation by Mr. Lyell, has indeed hitherto been, " That the 



time 



