PROGRESS OF PHYSICAL GEOLOGY. 581 



and especially that part of it which is requisite for the induction of laws 

 from facts, emerges slowly and with difficulty from the crowd of 

 adverse influences, even under the most favorable circumstances. We 

 have seen that in the ancient world, the Greeks alone showed them- 

 selves to possess this talent ; and what they thus attained to, amounted 

 only to a few sound doctrines in astronomy, and one or two extremely 

 imperfect truths in mechanics, optics, and music, which their succes- 

 sors were unable to retain. No other nation, till wfe corne to the dawn 

 of a better day in modern Europe, made any positive step at all in 

 sound physical speculation. Empty dreams or useless exhibitions of 

 ingenuity, formed the whole of their essays at such knowledge. 



It must, therefore, independently of positive evidence, be considered 

 as extremely improbable, that any of these nations should, at an early 

 period, have arrived, by observation and induction, at wide general 

 truths, such as the philosophers of modern times have only satisfied 

 themselves of by long and patient labor and thought. If resem- 

 blances should be discovered between the assertions of ancient writers 

 and the discoveries of modern science, the probability in all cases, the 

 certainty in most, is that these are accidental coincidences ; that the 

 ancient opinion is no anticipation of the modem discovery, but is one 

 guess among many, not a whit the more valuable because its expres- 

 sion agrees with a truth. The author of the guess could not intend 

 the truth, because his mind was not prepared to comprehend it. 

 Those of the ancients who spoke of the harmony which binds all 

 things together, could not mean the Newtonian gravitation, because 

 they had never been led to conceive an attractive force, governed by 

 definite mathematical laws in its quantity and operation. 



In agreement with these views, we must, I conceive, estimate the 

 opinions which we find among the ancients, respecting the changes 

 which the earth's surface has undergone. These opinions, u hen they 

 are at all of a general kind, are arbitrary fictions of the fancy, showing 

 man's love of generality indeed, but indulging it without that expense 

 of labor and thought which alone can render it legitimate. 



O ' 



We might, therefore, pass by all the traditions and speculations of 

 Oriental, Egyptian, and Greek cosmogony, as extraneous to our subject. 

 But since these have recently been spoken of, as conclusions collected, 

 however vaguely, from observed facts, 1 we may make a remark or two 

 upon them. 



1 Lyell, B. i. c. ii. p. 8. (4th ed.) 



