ANNIVERSARY ADDRESS OF THE PRESIDENT. 221 



generalizations, founded on the most scanty and imperfect observa- 

 tions, which were then misnamed science, we may well look back with 

 satisfaction to the work of the last thirty years, to which this Society 

 has contributed no inconsiderable share. 



It has hitherto too frequently happened that geologists have dealt 

 with important questions of physics, chemistry, comparative ana- 

 tomy, zoology, or botany, without an adequate acquaintance with 

 the principles and known laws of the science essentially involved in 

 the question; now, unless our conclusions will bear the test of the 

 most strict examination by those who are acknowledged authorities 

 in the particular science, it is obvious that we cannot make any 

 secure progress. The study of Geology, more perhaps than that of 

 any other branch of natural science, has a tendency to create a dis- 

 position to theorize ; this disposition, however, if kept within due 

 bounds, is rather to be encouraged than repressed, for it has often 

 proved a stimulus to accurate observation ; and to arrive at a know- 

 ledge of a true theory of the earth, is, in truth, the great aim of our 

 inquiries. But we must carefully guard against the error which the 

 earlier geologists too frequently fell into, of quitting the sober path 

 of inductive philosophy, and wandering into the regions of imagina- 

 tion. We must indulge in no theory that is not in accordance with 

 laws of nature of which we have had experience, or which may be 

 fairly inferred from that experience, although the operations we 

 seek to explain may have been on a greater scale than any of which 

 we have certain knowledge. The cautious and accurate Playfair 

 was wont to inculcate upon those who studied in the school of Hut- 

 ton, the warning of the noble aphorism with which Bacon opens his 

 great work, the ' Novum Organum,' — an aphorism which every geo- 

 logist will do well to bear in mind when he ventures to theorize on 

 causes : — " Homo, naturce minister et interpres, tantum facit et in- 

 telligity quantum, de naturce ordine, re vel mente ohservaverit ; nee 

 amplius scit, aut potest r 



