The arte of logick Plainely taught in the English tongue, according to the best approued authors. Very necessary for all students in any profession, how to defend any argument against all subtill sophisters, and cauelling schismatikes, and how to confute their false syllogismes, and captious arguments. By M. Blundevile.

Of a Syllogisme, what it is, how it is diuided; and of what parts it consisteth.

WHat is a Syllogisme?

A Syllogisme is a kind of argument contai∣ning three Propositions, whereof the two first, commonly called the premisses, being disposed according to moode, and figure, and granted, the third Propositiō, otherwise called the conclusion, differing from the other two, followeth of necessitie, by vertue of the premisses: how these three Propositions are called, and what moode and figure is, shall be declared hereafter; In the meane time marke wel the two other points touching this Definition: first, that the Conclusion must not be all one, but differing from the premisses: secondly, that the said Conclusion bee necessa∣rily inferred of the premisses, as in this example: euery sensible body is a substance: euery man is a sensible bodie: Ergo, eue∣ry man is a substance: for if the Conclusion were thus: Ergo, euery sensible body is a substance, or euery man is a sensible bodie, the argument should not be good, because the Con∣clusion should be all one with one of the premisses: the reason why the Conclusion must needes be inferred of the premisses, and so consequently follow of the same, shalbe declared vnto you hereafter.

How is a Syllogisme diuided according to the Schoolemen?

First, they diuide it according to the diuersity of the Propo∣sitions wherofit consisteth, into two kinds, viz. Categoricall, and Hypotheticall, (that is to say) simple and compound, cal∣ling that simple, which is made of simple Propositions, and that compound, which is made of compound Propositions: what simple and compound Propositions are, hath beene be∣fore* 1.1 defined. Againe, they diuide the simple Syllogisme three maner of wayes, first according to the diuersitie of the termes into a common and into a singular Syllogisme, for if the terms whereof the Syllogisme consisteth, bee common, or generall, and specially the meane terme, or proofe, then that Syllogisme is called a common Syllogisme: but if the meane terme or proofe be Indiuiduum, then that Syllogisme is said to be a sin∣gular Syllogisme, called of them, Syllogismus expositorius, wher∣of we shall speake hereafter: Secondly, they diuide a simple Syllogisme, according to the diuersitie of the figure, into a perfect, and vnperfect Syllogisme.

When is it said to be perfect?

When it needeth not to be altered any maner of way, other∣wise then it is, that the consequent may manifestly appeare.

When is it said to be vnperfect?

When the Consequent doth not manifestly appeare, vnlesse the Syllogisme be altered either by conuersion, or transposing of the premisses, whereof we shall speake hereafter: Thirdly, they diuide a simple Syllogisme, according to the matter of the Propositions whereof it is made, into three kindes, that is, into a Syllogisme Demonstratiue, Dialecticall, and Sophisti∣call: of which three kindes wee shall speake hereafter, and in their proper places; so as in all, the Schoolemen make foure seuerall diuisions of a Syllogisme, the first according to the di∣uersitie of the Propositions, the second according to the di∣uersity of the Termes, the third according to the diuersitie of the figure, and the fourth according to the diuersitie of the matter of the Propositions whereof wee haue spoken before, and shewed how manifold such matter is: but in the meane time wee will shew you of what parts a simple common Syllo∣gisme consisteth.

Of how many parts doth a simple Syllogisme consist?

Of two; that is, Matter, and Forme.

Notes

• * 1.1

  Lib. 3. cap. 1.