—and likewise knowledge and ignorance, deafness, muteness, and the like.

Second point: one may say that this entire division overlaps, for ʿadam-wa-malakah (privation and possession) already falls under salb-wa-ijab (negation and affirmation); it is merely a species of it. In the same way, the correlatives (mutadāyifān) belong to the broader class of contraries (mutadādān) and are nothing more than one of its kinds.

If someone objects, “By negation and affirmation I mean only that which does not include privation and possession—namely, to deny of a subject what it is not receptive to; hence one of its distinctive traits is that there is no impossibility in either member changing into the other,”

we answer him in two ways:

First, at most negation divides into two categories. The first is the negation of something a thing could in principle possess; the second is the negation of something it cannot possibly possess. Corresponding to the first is the affirmation of what the thing may possess but is not obliged to, and corresponding to the second is the affirmation of what it must necessarily possess. In other words, what is really at issue is the negation of the impossible and the affirmation of the necessary, as when we say, “Zayd is an animal”—an affirmation of the necessary—or “Zayd is not a stone”—a negation of the impossible.

On this reckoning, contingent beings that can admit both existence and non-existence