PRELUDE. 57 



doctrines as those which have been mentioned, were better suited to 

 the dim magnificence of poetry, than to the purpose of a philosophy 

 which was to bear the sharp scrutiny of reason. When we speak of 

 the 'principles of things, the term, even now, is very ambiguous and 

 indefinite in its import, but how much more was that the case in the 

 first attempts to use such abstractions ! The term which is commonly 

 used in this sense (apx^)? signified at first the beginning ; and in its 

 early philosophical applications implied some obscure mixed reference 

 to the mechanical, chemical, organic, and historical causes of the visible 

 state of things, besides the theological views which at this period were 

 only just beginning to be separated from the physical. Ilence we are 

 not to be surprised if the sources from which the opinions of this period 

 appear to be derived are rather vague suggestions and casual analogies, 

 than any reasons which will bear examination. Aristotle conjectures, 

 with considerable probability, that the doctrine of Thales, according 

 to which water was the universal element, resulted from the manifest 

 importance of moisture in the support of animal and vegetable life. 3 

 But such precarious analyses of these obscure and loose dogmas of early 

 antiquity are of small consequence to our object. 



In more limited and more definite examples of inquiry concerning 

 the causes of natural appearances, and in the attempts made to satisfy 

 men's curiosity in such cases, we appear to discern a more genuine 

 prelude to the true spirit of physical inquiry. One of the most remark- 

 able instances of this kind is to be found in the speculations which 

 Herodotus records, relative to the cause of the floods of the Nile. 

 " Concerning the nature of this river," says the father of history/ " I 

 was not able to learn any thing, either from the priests or from any- 

 one besides, though I questioned them very pressingly. For the Nile is 

 flooded for a hundred days, beginning with the summer solstice ; and 

 after this time it diminishes, and is, during the whole winter, very 

 small. And on this head I was not able to obtain any thing satisfac- 

 tory from any one of the Egyptians, when I asked what is the power 

 by which the Nile is in its nature the reverse of other rivers." 



^ e may see, I think, in the historian's account, that the Grecian 

 mind felt a craving to discover the reasons of things which other 

 nations did not feel. The Egyptians, it appears, had no theory, and 

 felt no want of a theory. Not so the Greeks ; they had their reasons 

 t<> render, though they were not such as satisfied Herodotus. " Some 



3 Metaph. i. 3. " Herod, ii. 19. 



