GENERALISATION OF LAWS. 65 



earliest of these attempts are found in the treatises of the 

 Ionic school on the principles of things ; treatises in which 

 the whole of nature was subjected to rash speculation, with 

 only an extremely scanty basis of observation. This ardour 

 for deductively determining the essence of things and their 

 mutual connection from an ideal construction and purely 

 rational principles, has gradually subsided, with the increas- 

 ingly brilliant development of the natural sciences resting 

 on the firm support of observation. Nearer to our own 

 time, the mathematical portion of natural philosophy has 

 received the grandest and most admirable enlargement. The 

 method, and the instrument (analysis), have both been per- 

 fected together. We are of opinion, that what has been 

 conquered by means so diverse, by the ingenious application 

 of atomic suppositions, by the more general and more inti- 

 mate study of phenomena, and by new and improved 

 apparatus, is the common property of mankind ; and cannot 

 now, any more than in the times of the ancients, be with- 

 drawn from the free exercise of speculative thought. It 

 cannot be denied that the results of experience may have 

 been sometimes undervalued in the course of such processes; 

 nor ought we to be too much surprised if in the perpetual 

 fluctuations of speculative views, as the author of Giordano 

 Bruno ( 30 ) has ingeniously remarked, " most men see in 

 philosophy only a succession of passing meteors ; and even 

 the grander forms under which she has revealed herself 

 partake in the popular estimation of the fate of comets, 

 which they regard as belonging not to the class of perma- 

 nent celestial bodies, but to that of mere passing igneous 

 vapours." But the abuse of speculative thought, and the 

 false paths into which it has sometimes strayed, ought not to 



