INTncDUCTIOX. <^ 



country, before unknown to him, he naturally begins by taking, from some 

 elevated situation, a distant view of the distribution of its parts ; and in the 

 same manner, before we enter on the particular consideration of the subjects 

 of our researches, it may be of use to form to ourselves a general idea of the 

 sciences and arts which are to be placed among them. 



Upon the advantages of mathematical and philosophical investigation in 

 general, it is unnecessary to enlai'ge, because no liberal mind can require any 

 arguments to be convinced how much the judgment is strengthened, and the 

 invention assisted, by habits of reasoning with caution and accuracy. The 

 public opinion is rather, on the contrary, in danger, at least in some paits of 

 the world, of being too exclusively biassed in favour of natural philosophy j 

 and has sometimes been mclined to a devotion too much limited to science, 

 without a sufficient attention to such literature as an elegant mind always de- 

 sires to see united with it. As to the practical importance of philosophical 

 tlieories of the arts, it may have been overrated by some, but no person is 

 authorised to atTirm, rhat.it has been too highly estimated, unless he has made 

 himself master of every thing that theory is capable of doing; such a one, 

 although he may in some cases be obliged to confess the insufficiency of our 

 calculations, Avill never have reason to complain of their fallacy. 



The division of the whole course of lectures into three parts, was originally 

 suggested by the periodical succession in which the appointed hours recur: but 

 it appears to be more convenient than any other for the regular classification 

 of the subjects. The general doctrines of motion, and their application to all 

 purposes variable at pleasure, supply the materials of the first two parts, of 

 which the one treats of the motions of solid bodies, and the other of those of 

 fluids, inclftding the theory of light The third part relates to the particular 

 history of the phenomena of nature, and of the affections of bodies actually 

 existing in the universe, independently of the art of man; comprehending 

 astronomy, geography, and the doctrine of the properties of matter, and of 

 the most general and powerful agents that influence it t^' 



4.1 j-i 



■ The synthetical order of proceeding, from simple and general principles, 

 to their more intricate combinations in particular cases, is by far the most 

 compendious for conveying information, with regard to sciences that are at all 



VOL. I. c 



