BOOK IV. 



OF OPERATIONS SUBSIDIARY TO INDUCTION. 



*' Clear and distinct ideas are terras which, though familiar and frequent in men's mouths, 

 I have reason to think every one who uses does not perfectly understand. And possibly it 

 is but here and there one who gives himself the trouble to consider them so far as to know 

 what he himself or others precisely mean by them; 1 liave, therefore, in most places, 

 chose to put determinate or determmed, instead of clear and distinct, as more likely ta 

 direct men's, thoughts to my meaning in this matter." — Locke's Ensay on the Human Un- 

 derstandiiig ; Epistle to the Reader. 



" According to this view of the process of the mind, in carrying on general speculations, 

 that Idea which the ancient philosophers considerea as the essence of an individual, is 

 nothing more than the particular quality or qualities in which it resembles other imlividuals 

 of the same class; and in consequence of which, a generic name is applied to it." — D. 

 Stewart, Phil, of the Human Mind, ch. iv., sec. 2. 



" Deux grandes notions philosophiques domiiient la theorip fondamentale de la methode 

 naturelle proprement ditc, savoir, la foimation des groupes naturels, et ensuite leur suc- 

 cession hierarchique." — Ccmte, Cours de Philosophic Positive, 42me leqon 



CHAPTER I. 



OP OBSERVATION, AND DESCRIPTION. 



§ 1. The inquiry which occupied us in the two preceding Books, 

 has conducted us to what appears a satisfactory solution of" the ])nncipal 

 problem of Lot^c, according to the conception I have formed of the 

 science. We have found, that the mental process with which Logic 

 is conversant, the operation of investigating truths by means of e\adence, 

 is always, even when appearances point to a different theory of it, a 

 process of induction. And we have particularized tlie various modes 

 of induction, and obtained a clear view of the principles to which it 

 must conform, in order to lead to results which can be relied on. 



The consideration of induction, however, does not end with the 

 direct rules for its performance. Something must be said of those 

 oth(!r operations of the mind, which are either necessarily presupposed 

 in all induction, or are instrumental to the more difficult and compli- 

 cated inductive processes. The present Book will be devoted to the 

 consideration of these subsidiary operations : among which our atten- 

 tion must first be given to those, which are indispensable preliminariea 

 to all induction whatsoever. 



Induction being merely the extension to a class of cases, of some- 

 thing which has been observed to be true in certain individual instances 

 of the class; the fir.st place among the operations subsidiary to induc- 

 tion, is claimed l)y Observation, TliLs is oot, however, the place to 

 lay down rules for making good ob.ser\-crs ; nor is it within the com- 

 petence of Logic to do so, but of the art of intellectual Education. 

 Our business with Observation is only in its connexion with the ap- 



