BOOK II. 



OF REASONING. 



Ai(opiafiiv(ov dt Toiru)v Xkyufisv i'/St], Sid rivwv, Kal ttoti, Kai Truif yiverat nag avWoyiafioQ 

 vffrepov dk Xiktcov Trspl atroSii^tbjg. UpoTtpov yap Trepl (rvWoyiufiov Xekteov, rj vepi diroSei- 

 ^ewg, Sid rb KaGoXov /xaXXov uvai top avXKoyi(T}x6v. 'H fiiv yap aTToSu^iQ, (TvXXoyi(Tfi6g rig' 6 

 avXXoyiffixog 6e ov ■kclq, diroSu^iQ. — Akist., Analyt. Prior., 1. i., cap. 4. 



CHAPTER I. 



OF INFERENCE, OR REASONING, IN GENERAL. 



§ 1. In the preceding Book, we have been occupied not Avith the nature 

 of Proof, but with the nature of Assertion : the import conveyed by a Prop- 

 osition, whether that Proposition be true or false ; not the means by which 

 to discriminate true from false Propositions. The proper subject, however, 

 of Logic is Proof. Before we could understand what Proof is, it was nec- 

 essary to understand what that is to which proof is applicable ; what that 

 is which can be a subject of belief or disbelief, of affirmation or denial; 

 what, in short, the different kinds of Propositions assert. 



This preliminary inquiry Ave have prosecuted to a definite result. Asser- 

 tion, in the first place, relates either to the meaning of words, or to some 

 property of the things which words signify. Assertions respecting the 

 meaning of words, among which definitions are the most important, hold a 

 place, and an indispensable one, in philosophy ; but as the meaning of words 

 is essentially arbitrary, this class of assertions are not susceptible of truth 

 or falsity, nor therefore of proof or disproof. Assertions respecting Things, 

 or what may be called Real Propositions, in contradistinction to verbal 

 ones, are of various sorts. We have analyzed the import of each sort, and 

 have ascertained the nature of the things they relate to, and the natui-e of 

 what they severally assert respecting those things. We found that what- 

 ever be the form of the proposition, and whatever its nominal subject or 

 predicate, the real subject of every proposition is some one or more facts 

 or phenomena of consciousness, or some one or more of the hidden causes 

 or powers to which we ascribe those facts ; and that what is predicated or 

 asserted, either in the affirmative or negative, of those phenomena or those 

 powers, is always either Existence, Order in Place, Order in Time, Causa- 

 tion, or Resemblance. This, then, is the theory of the Import of Proposi- 

 tions, reduced to its ultimate elements : but there is another and a less ab- 

 struse expression for it, which, though stopping short in an earlier stage of 

 the analysis, is sufficiently scientific for many of the purposes for which 

 such a general expression is required. This expression recognizes the com- 

 monly received distinction between Subject and Attribute, and gives the 

 following as the analysis of the meaning of propositions : — Every Proposi- 



