Universa Philosophia

=== ENGLISH Moreover note that there are falsifying propositions, which destroy themselves; for example, someone says, ego sum mutus, qui non loquor, ego iuro me numquam iurare, ego semper mentior; behold these are falsifying. The first, because he says he does not speak, when nevertheless he speaks; the second, because he says he does not swear, and nevertheless he swears. The third, because he says he always lies, when nevertheless by that proposition he destroys what he says, because if he always lies, therefore he also lies then; but if he lies then, therefore he says the truth, because he says what is; but if he does not lie then, therefore he does not always lie. Likewise these are falsifying: Deus dabit mihi librum, Deus non dabit mihi librum, given this case, that someone says to Peter, Deus tibi dabit librum, si prima propositio, quam dixeris, fuerit vera, and then Peter says, Deus mihi non dabit librum, this proposition is falsifying, because it is impossible for the promise to be fulfilled, because if God gives the book, that first proposition was not true; but if God does not give the book, that proposition was true, and it cannot be fulfilled, nor can it be promised thus by God. Therefore if you pay attention to falsifying propositions, and likewise to the circumstances of the subject, predicate and negation, you will never be caught, but you will easily fall into the hands of the enemy if you gape. But what is said, nulla est melior contradictio, quam toti propositioni negationem praeponere: understand it if the negation is not infinitizing; but if it is infinitized, it is not a contradiction.

But in exclusive propositions this rule is false, as will be clear in section 13, where the opposition of exclusives will be treated.

Omnis homo currit.	Contraries.	Nullus homo currit.
Subaltern affirmative.	↖ Contradictories. ↘ · ↙ Contradictories. ↗	Subaltern negative.
Aliquis homo currit.	Subcontraries.	Aliquis homo non currit.