that the negation should deny the same thing which the affirmation affirmed, and also from the same, (i. e.) either from some singular or some universal, universally or not universally; I say, for instance, that "Socrates is white," "Socrates is not white." If however there is something else from the same thing, or the same thing from something else, that (enunciation) will not be opposite, but different from it; to the one, "every man is white," the other (is opposed) "not every man is white," and to the one, "a certain man is white," the other, "no man is white;" and to the one, "man is white," the other, "man is not white."
That there is then one affirmation contradictorily opposed to one negation, and what these are, has been shown, also that there are other contraries, and what they are, and that not every contradiction is true or false, and why and when it is true or false.
