Page:O. F. Owen's Organon of Aristotle Vol. 1 (1853).djvu/124

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tain C, but A may happen to be present with every C, and yet A is not necessarily so with B, for a certain "biped" need not "sleep" or "wake." So also we may demonstrate it by the same terms if A be particular and necessary. But if one term be affirmative and the other negative, when the universal proposition is negative and necessary, the conclusion will also be necessary, for if A happens to no C, but B is present with a certain C, A must necessarily not be present with a certain B. But when the affirmative is assumed as necessary, whether it be universal or particular, or particular negative, there will not be a necessary conclusion, for we may allege the other same (reasons against it), as in the former cases. But let the terms when the universal affirmative is necessary be "wakefulness," "animal," "man," the middle "man." But when the particular affirmative is necessary, let the terms be "wakefulness," "animal," "white," for "animal" must necessarily be with something "white," but "wakefulness" happens to be with nothing "white," and it is not necessary that wakefulness should not be with a certain animal. But when the negative particular is necessary, let the terms be "biped," "motion," "animal," and the middle term, "animal."