Page:Herschel - A Preliminary Discourse on the Study of Natural Philosophy (1831).djvu/26

This page has been proofread, but needs to be validated.
12
DISCOURSE ON THE STUDY

were men of superior minds, who reasoned while they worked, and who, not content to grope always in the dark, and blunder on their object, sought carefully in the observed nature of their agents for guides in their pursuits;—to these we owe the creation of experimental philosophy.

(8.) Not that it is meant, by any thing above said, to assert that there is no such thing as a great or a little in speculative philosophy, or to place the solution of an enigma on a level with the developement of a law of nature, still less to adopt the homely definition of Smith[1], that a philosopher is a person whose trade it is to do nothing, and speculate on every thing. The speculations of the natural philosopher, however remote they may for a time lead him from beaten tracks and every-day uses, being grounded in the realities of nature, have all, of necessity, a practical application,—nay more, such applications form the very criterions of their truth, they afford the readiest and completest verifications of his theories;—verifications which he will no more neglect to test them by than an arithmetician would omit to prove his sums, or a cautious geometer to try his general theorems by particular cases,[2]

  1. Wealth of Nations, book i. chap. i. p. 15.
  2. On this subject, we cannot forbear citing a passage from one of the most profound but at the same time popular writers of our time, on a subject unconnected it is true with our own, but bearing strongly on the point before us. "But, if science be manifestly incomplete, and yet of the highest importance, it would surely be most unwise to restrain enquiry, conducted on just principles, even where the immediate practical utility of it was not visible. In mathematics, chemistry, and every branch of natural philosophy, how many are the enquiries