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. VII.

Of the proposition, equiualencie, and conuersion of modall propositions.

WE told you before, that of modall propositions, some were called coniunct, and some disiunct: and as for the modals disiunct, they differ but lit∣tle from absolute propositions before declared. And therefore we haue here chiefly to deale with opposition, equiualencie, and conuersion belonging to modall coniunct, the matter whereof being not altogether so necessarie as some men affirme, I minde to make no long speech thereof. But for the better vnderstanding of opposition, equiualencie▪ and conuersion thereof, it is needfull first to declare the quantitie and qualitie of a modall proposition: of both which things, though Aristotle maketh no mention, but only a little of qualitie; yet the latter Writers doe necessarily suppose modall propositions to bee indued with quantitie and qualitie: for they say that the mood necessarie is much like to a signe vniuersall affirmatiue; the mood impossible, to a signe vniuersall negatiue; the moods possible and contingent, which are both of one value, are like to signes particu∣lar

affirmatiue. Now as touching the qualitie, which is to be ei∣ther affirmatiue or negatiue, like as the negatiue in absolute pro∣positions is wont to bee added to the verbe, euen so in modall propositions it is added to the mood, as by the examples set down in the figure of opposition hereafter following ye may easily per∣ceiue.