BOOK III. 



OF INDUCTION. 



"According to the doctrine now stated, the highest, or rather the only proper object of 

 physics, is to ascertain those estabhshed conjunctions of successive events, which constitute 

 the order of the universe ; to record the phenomena which it exhibits to our observations, or 

 which it discloses to our experiments ; and to refer these phenomena to their general laws." 

 — D. Stewart, Elements of the Philosophy of the Human Mind, vol. ii., chap, iv., sect. 1. 



"In such cases the inductive and deductive methods of inquiry may be said to go hand in 

 hand, the one verifying the conclusions deduced by the other ; and the combination of experi- 

 ment and theoiy, which may thus be brought to bear in such cases, forms an engine of dis- 

 covery infinitely more powerful than either taken separately. This state of any department 

 of science is perhaps of all others the most interesting, and that which promises the most to 

 research. " — Sir J. Herschel, Discourse on the Study of Natural Philosophy. 



CHAPTER I. 



PRELIMINARY OBSERVATIONS ON INDUCTION IN GENERAL. 



§ 1. The portion of the present inquiry upon which we are now about 

 to enter, may be considered as the principal, both from its surpassing in 

 intricacy all the other branches, and because it relates to a process which 

 has been shown in the preceding Book to be that in which the investiga- 

 tion of nature essentially consists. We have found that all Inference, con- 

 sequently all Proof, and all discovery of truths not self-evident, consists of 

 inductions, and the interpretation of inductions : that all our knowledge, 

 not intuitive, comes to us exclusively from that source. What Induction 

 is, therefore, and what conditions render it legitimate, can not but be deem- 

 ed the main question of the science of logic — the question which includes 

 all others. It is, however, one which professed writers on logic have al- 

 most entirely passed over. The generalities of the subject have not been 

 altogether neglected by metaphysicians ; but, for want of sufficient ac- 

 quaintance with the processes by which science has actually succeeded in 

 establishing general truths, their analysis of the inductive operation, even 

 when unexceptionable as to correctness, has not been specific enough to be 

 made the foundation of practical rules, which might be for induction itself 

 what the rules of the syllogism are for the interpretation of induction : 

 while those by whom physical science has been carried to its present state 

 of improvement — and who, to arrive at a complete theory of the process, 

 needed only to generalize, and adapt to all varieties of problems, the meth- 

 ods which they themselves employed in their habitual pursuits — never un- 

 til very lately made any serious attempt to philosophize on the subject, nor 

 regarded the mode in which they arrived at their conclusions as deserving 

 of study, independently of the conclusions themselves. 



