FOr the better vnderstanding of the lawes belon∣ging to the opposites, it shall bee necessarie to speake somewhat of the matter of a proposition, whereupon the said lawes doe partly depend.
Threefold, that is to say, naturall, casuall, and remote or vnnaturall.
When the predicat agreeth with his subiect essentially, or at the least necessarily: as when the generall kinde is spoken of his speciall kinde, and the speciall kinde of his Indiuiduums, or the difference of his speciall kinde, or the propertie of his subiect: as, Euery man is a sensible body, Iohn is a man, Euery man is rea∣sonable, Euery man is apt to speake.
When the predicat agreeth with his subiect accidentally, so as it may either be, or not be; as, Iohn is learned.
When the predicat agreeth no manner of way with the sub∣iect; as, A man is a horse, A man is a stone, &c.
Contrarie propositions can be true no way both together; as, Euery man is a sensible body, No man is a sensible body: but they may be both false, and specially consisting of matter contin∣gent; as when I say, Euery man is iust, No man is iust, which are both false.
Subcontrarie propositions, consisting of matter naturall, can∣not be both false at once; as, Some man is a sensible body, Some man is not a sensible body: but consisting of matter contingent▪ both may be sometime true; as, Some man is iust, Some man is not iust.