596 HISTORY OF GEOLOGY. 



geology. We may, indeed, readily believe that we have much to do 

 in both these departments. While so large a portion of the globe is 

 geologically unexplored ; while all the general views which are to 

 extend our classifications satisfactorily from one hemisphere to another, 

 from one zone to' another, ai'e still unformed; while the organic fossils 

 of the tropics are almost unknown, and their general relation to the 

 existing state of things has not even been conjectured ; how can we 

 expect to speculate rightly and securely, respecting the history of the 

 whole of our globe ? And if Geological Classification and Description 

 are thus imperfect, the knowledge of Geological Causes is still more so. 

 As we have seen, the necessity and the method of constructing a science 

 of such causes, are only just beginning to be perceived. Here, then, 

 is the point where the labors of geologists may be usefully applied ; 

 and not in premature attempts to decide the widest and abstrusest 

 questions which the human mind can propose to itself. 



It has been stated, 11 that when the Geological Society of London 

 was formed, their professed object was to multiply and record observa- 

 tions, and patiently to await the result at some future time ; and their 

 favorite maxim was, it is added, that the time was not yet come for a 

 General System of Geology. This was a wise and philosophical tem- 

 per, and a due appreciation of their position. And even now, their 

 task is not yet finished ; their mission is not yet accomplished. They 

 have still much to do, in the way of collecting Facts ; and in entering 

 upon the exact estimation of Causes, they have only just thrown open 

 the door of a vast Labyrinth, which it may employ many generations 

 to traverse, but which they must needs explore, before they can pene- 

 trate to the Oracular Chamber of Truth. 



I REJOICE, on many accounts, to find myself arriving at the termina- 

 tion of the task which I have attempted. One reason why I am glad 

 to close my history is, that in it I have been compelled, especially in 

 the latter part of my labors, to speak as a judge respecting eminent 

 philosophers whom I reverence as my Teachers in those very sciences 

 on which I have had to pronounce a judgment ; if, indeed, even the 

 appellation of Pupil be not too presumptuous. But I doubt not that 

 such men are as full of candor and tolerance, as they are of knowledge 

 and thought. And if they deem, as I did, that such a history of 



11 Lyell, B. i. c. iv. p. 103. 



