The opening of Preface
TO
THE PRESENT EDITION.
IN the study of Nature, either mental or physical, the aim of the scientific enquirer is to diminish as much as possible the catalogue of ultimate truths. When, without doing violence to facts, he is able to bring one phenomenon within the laws of another; when he can shew that a fact or agency, which seemed to be original and distinct, could have been produced by other known facts and agencies, acting according to their own laws; the enquirer who has arrived at this result, considers himself to have made an important advance in the knowledge of nature, and to have brought science, in that department, a step nearer to perfection. Other accessions to science, however important practically, are, in a scientific point of view, mere additions to the materials: this is something done towards perfecting the structure itself.