270 FINAL CAUSES : THEIR BEARING 



we, cannot deduce a reason for their rise or decline, or whj 

 their term of being should have been included rather in one 

 certain period of time than another. The same faculty which 

 finds employment in tracing to their causes the rise and fail 

 of nations, and which it is the merit of the philosophic his- 

 torian judiciously to exercise, will to a certainty seek em- 

 ployment in this department of histoiy also ; and that there 

 will be an appetency for such speculations in the public mind, 

 we may infer from the success, as a literary undertaking, of 

 the " Vestiges of Creation," — a work that bears the same 

 sort of relation, in this special field, to sober inquiry founded 

 on the true conditions of things, that the legends of the old 

 chroniclers bore to authentic history. The progressive state 

 of geologic science has hitherto militated against the forma- 

 tion of theory of the soberer character. Its facts, — still 

 merely in the forming, — are necessarily imperfect in their 

 classification, and limited in their amount ; and thus the 

 essential data continues incomplete. Besides, the men best 

 acquainted with the basis of fact which already exists have 

 quite enough to engage them in adding to it. But there are 

 limits to the field of palseontological discovery, in its relation 

 to what may be termed the chronology of organized exist- 

 tence, which, judging from the progress of the science in the 

 past, may be well-nigh reached in favoured localities, such as 

 the British islands, in about a quarter of a century from the 

 present time ; and then, I doubt not, geological history, in 

 legitimate conformity with the laws of mind, and from the 

 existence of the pregnant principle peculiar, according to 

 Cuvier, to that science of which Geology is simply an exten- 

 sion, will assume a very extraordinary form. We cannot 

 yet aspire " to the height of this great argument ;" our foun- 

 dations are in parts still unconsolidated and incomplete, and 

 unfitted to sustain the perfect superstructure which shall one 

 day assuredly rise ni>on them ; but from the little which we 



