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.

CHAP. XI.

Of the truth and falshood of Hypotheticall propositions, and first, of the Conditionall.

WHat is to be considered, to know the truth or falshood of Conditionall Propositions?

First, whether they be affirmatiue or nega∣tiue: for in the affirmatiues it sufficeth, that the one part doth necessarily follow of the o∣ther, as thus: If it be a man, it is a sensible body: and it ma∣keth no matter, though the parts seuerally taken, be both false, so as the Cousequent be good: as, If a tree be a man, a tree is a sensible bodie: for though both these parts be false, yet the

Consequent conditionally is true: for a conditionall Proposi∣tion hath no regard to the truth of the parts, but onely that the Consequent may necessarily follow of the Antecedent.

How is the truth of the negatiue Proposition to be knowne?

By the Consequent: for if the Consequent bee not rightly inferred of the antecedent, then the negatiue is true, as thus: it followeth not that because a Lyon is a sensible body, that therefore a Lyon is a man.

Of the truth and falshood of propositions copulatiue.

WHen is a copulatiue Proposition said to be true or false?

It is said to be true, when both the parts bee true, as when I say, God is true, and man is a lyar: againe it is said to be false, when either one part or both parts be false: as when I say, man is a sensible bodie, and God is not a Spirit. Here be∣cause the first part is true, and the second part false, the whole Proposition is said to be false. It is said also to be false, when both parts are false, as thus; Man is true, and God is a lyar. Heere both parts be false.

What kinde of propositions are wont to bee referred to this co∣pulatiue?

Those which they call Temporall, Locall, by similitude and causall: as of time thus, When a penitent sinner pray∣eth, then God heareth him. Of place thus, Where two or three are gathered together in the Name of the Lord, he is in the midst of them. By similitude thus, As a man dealeth with his neighbour, so will God deale with him. Of the cause thus, Because the Sunne shineth, it is day. And therefore certaine Aduerbes as these, When, Where, Vntill, so long as, as, so as, for, therefore, because and such like, haue the signification sometime of the Coniunction (And) and sometime of the Con∣iunction (If).

Of the truth and falshoode of disiunctiues.

WHat belongeth properly to disiunctiue Propositions?

To consist of repugnant parts, according to the

signification of Coniunctions disiunctiue, such as these bee, vel or eyther, or else, and such like: as eyther it is day, or it is night, whereof the one destroyeth the other: for if the one be, the other can not be: and therefore they can not bee both true: but they may be both false, if there be any mean betwixt the two contraries: as when wee say, This woman is eyther white or blacke, both these are false, if she be browne, which is a meane colour betwixt white and blacke. But the later writers affirme the disiunctiue to bee true, if any one or both of the parts bee true, as thus, Eyther a man is a sensible body, or else a tree is a Substance: and to bee false when both parts bee false, as Eyther a man is true, or God is a lyar.