310 
ON THE OPINIONS OF VOLTAIRE AND LAPLACE 
REGARDING GEOLOGY. 
By Pbof. P. MAKTIN DUNCAN, F.RS. &c. 
G EOLOGY, tlie science which investigates the successive 
changes that have modified the aspect of the surface of 
the earth, has passed through many phases during its long his- 
tory. Depending much on the success of many other sciences, 
it has progressed or retrograded with them, and coming into op- 
position with religious tradition it has suffered during centuries. 
The history of geology has been closely connected with that of 
liberal intellectual culture in Europe, and the progress of the 
broad and very eclectic science has been synchronous with the 
development of civil and religious liberty. On the other hand, 
superstition and dogma have interfered with every branch of 
it, and the whole study had its age of mediaeval darkness. 
The science arose with the highest development of Grecian 
civilization, and made no small advance ; and the Pythagorean 
doctrines, so full of truth regarding the phenomena of the 
former changes in the aspect of Nature, which have been 
handed down by Ovid, were the last and fullest expressions of 
the Grecian mind on geological subjects. No progress was 
made beyond them, and, indeed, they were considered heretical 
during the dark ages. From about 880 b.c. to the commence- 
ment of the sixteenth century of our era, no progress was 
made, and the published opinions of educated men regarding 
the earth, afford a melancholy instance of the subordination of 
the intellect. But light came at last, and where it might have 
been least expected by the student of general history. FraCastero 
and Leonardo da Yinci expressed the more liberal opinions of 
Italian observers of Nature, and insisted that the fossil shells 
so constantly seen in the sub-Apennine strata, were once living, 
and that the Mediterranean Sea had once a larger area and had 
retired. Palissy inculcated correct views regarding fossils, 
seventy years afterwards ; and his general belief in the former 
changes on the surface of the globe was that of the Greeks 
