We may remark of the Categories that attempts have been made to found a philosophical system upon them, as explained by Aristotle. They contain, as is observed by Dr. Whately, the explicit statement that though a primary substance signifies a particular thing, as " a particular man," " a particular horse," the general term " man " or " horse" (which he calls a secondary substance) only appears to denote a particular thing, but in fact does not ; for the thing is not one, as in the case of a "particular man," but is said of many (v. 16, ed. Pac.). This is a clear statement that general terms do not indicate realities, but are only the expression of the mode in which the mind is affected.
In tho Prior Analytics It has been stated that the pure syllogism is considered : the introductory chapter of the First Book states in a general way the objects of the science as conceived by Aristotle, and is expressed with his characteristic clearness.
" It is proper," says Aristotle, " first to state about what the inquiry is, and to what tho inquiry belongs, namely, demonstration and demon strative science. Then we must define Proposition (af-pill-arra), Term (Epos), and Syllogism (cruA)teaacrnbs) ; and what is a perfect and what an imperfect syllogism. Next, what is meant by one thing being or not being in the whole of another, and what we mean by a'thing being predicated of all or none. A proposition then is a (a67os) which affirms or denies something of another thing; and this either universally, or particularly, or indefinitely. By universally, I mean where it applies to all or none ; by particularly, where it appliee to part, or not a part, or not to all ; and by indefinitely, where it applies, or does not apply, without anything being determined as to the whole orjart. The demonstrative (ciroboucrur4) proposition differs from the dialectic (autAgeste.4). The demonstrative is an assumption of one side of the question, namely the contradiction ; for ho who demonstrates does not interrogate, but he costumes ; but the dialectic is an interro gation as to the contmdiction.* This, however, makes no difference with respect to the syllogism in either ease, for both ho who demon strates and he who interrogates syllogist, by assuming something to be predicated or not to be predicated of another thing. Consequently a syllogistic proposition will be simply an affirmation or denial of one thing with respect to another, in the way already mentioned ; and a proposition will be demonstrative if it is true, and obtained by means of the original hypothesis. A dialectic, proposition is, with respect to the question, an interrogation about denial ; but to him who syllogises, it is the assumption of that which is apparent and probable, as it is shown in the Topica. What then is a proposition, and in what respect a syllogistic, demonstrative, and dialectic proposition differ, will be accurately stated in what follows (in the' Analytica Posteriors '); but for the present purpose what has been already said is sufficient.
" I call Term that into which a proposition is resolved, as the pre dicate (eb ka-nryopoimtvor), and that of which predication is made, with the addition or not of ' being,' or not being.' A syllogism is discourse, in which certain things being laid down, something different from these things necessarily results by virtue of these premises (es; ectiera eTrat). And I mean by the words by virtue of the premises,' that this something results by reason of them (8th saiera): and by reason of them' means that no other term is needed in order to this necessary result. Now, I call that a perfect syllogism which requires nothing else besides what is assumed or granted in order that the necessary conclusion may appear. I call that an imperfect syllogism which requires, one or more things which are of necessity by virtue of the given terms, but are not assumed in the propositions. For one thing to be said to be in the whole of another, and one thing to be predicated of the whole of another, is the same thing; and I mean by predication of the whole of a thing, when one cannot conceive any part of the one thing (the subject) of which the other cannot be predicated; and the like when the predication is of no part of a thing." It was apparently the object of Aristotle in his so-called logical treatises, as we now have them, to make a perfect system of argu. mentative discourse, and not merely a logical (properly so called) system. It is probable that if all his works of this class were extant
and arranged according to his own method, we should see still more clearly that the whole was not considered a logical system (as the term logic is strictly understood), but that a logical system (as the term if strictly understood) was contained in it. Whether Aristotle or any other person put the existing books of the Organon together, neither the author who conceived them in connection with one another, no: any one else, considered them as forming n pure logical or even a pure dialectic treatise, but a treatise on argumentation. And this is cleat enough from an examination of the contents of the Organon, and the remarks of Cicero (Topica) and his commentator Boethius, who mu himself a writer on logic. Boethius, who uses the term Logic, inform: us that the Peripateties understood this term as Cicero understood it and Cicero defines it to be " disserendi diligens ratio," or " an exact method of argumentation." The l'cripateties, he adds, understood logic to consist in invention and judgment ; but the Stoics, who neg lected invention, considered it to consist in judgment only, which they distinguished by the name of dialectic. Thus the logic of the Peripa tetics was larger than the logic of the Stoics. The logic of the Peripatetic, consisted, first of topic or invention, which teaches the method of easily discovering arguments ; and Boethius remarks that Aristotle in hi, ' Topics' treats of the "maxi= prepositiones" (called loci), which an universal propositions, of undoubted truth, which need no demon stration, or probable propositions, and from which we descend to the con elusions of the syllogism. Judgment is more particularly exercised it making conclusions (in colligendi rations), but inasmuch as all argu mentation and syllogising depend on and are constructed of propositions we have to consider both the matter of propositions and their con nection. As to the matter, we have to consider whether the proposition, are true, or necessary, or probable, or sophistical. As to the connection we have to consider the union and the composition of the propositions which may be called the form of the arguments. Logic then consist of invention, and of the eonclumions from invention, or the form of th argumentation. The part which treats of invention supplies th instruments or means for invention, and, as already observed, is calls Topice. The part which relates to judgment supplies certain rules fo discerning or separating (discernendi), and is called Analytice: so LA as it treats of the connection or union of propositions, it is callei Analytice Prior ; so far as it treats of the inventions themselves, it i called Analytice Posterior, when it is engaged about discerning fleece Lary arguments ; but when it is engaged about false and deceptiv arguments (carillatoria), that is, sophistical, it is called the Elenchi Ifoethius then concludes that Aristotle treated of logic in a mor complete manner than the Stoics, "since he treated of the two things beside which there is no third, namely, invention and judgment, while the Stoics neglected invention and only furnished us with the instru ments of judgment." This statement of what the logic of Aristotle was, may help to remove certain long-rooted mistakes on the matter. Dr. Whately, who confines logic to the pure syllogism in his theoretical view of the subject, though not in his practical exposition of it, says that " with the exception of Aristotle, hardly a writer on logic can be mentioued who has clearly perceived, and steadily kept in view throughout, its real nature and object." And he remarks that even Aristotle is not entirely exempt from the error of mistaking the nature of logic, and extending it to subjects with which it has no proper connection. Now the fact is that Aristotle's logic, being what we have here explained it to be, is a very different thing from what it appears to be considered to be by many. To say that Aristotle is sot entirely exempt from the error above mentioned is rather a singular expression, when three fourths of his Organon have noticing at all to do with the pure syllo gism. In fact Aristotle's Organon, and his logic as explained by Boethius, are much more like Watts's much-abused Right Use of Reason' than like what many modern writers take them to be.