Page:O. F. Owen's Organon of Aristotle Vol. 1 (1853).djvu/113

 will be present with this, wherefore P will be present with a certain R, and if R is present with every S, but P is present with no S, there will be a syllogism, so that P will be necessarily inferred as not present with a certain R; for the same mode of demonstration will take place, the proposition R S being converted; this may also be demonstrated by the impossible, as in the former syllogisms. But if R is present with no S, but P with every S, there will not be a syllogism; let the terms of presence be "animal," "horse," "man," but of absence "animal," "inanimate," "man." Neither when both are predicated of no S, will there be a syllogism, let the terms of presence be "animal," "horse," "inanimate," but of absence "man," "horse," "inanimate," the middle "inanimate." Wherefore also in this figure it is evident, when there will, and when there will not, be a syllogism, the terms being universal, for when both terms are affirmative, there will be a syllogism, in which it will be concluded that extreme is with a certain extreme, but when both terms are negative there will not be. When however one is negative and the other affirmative, and the major is negative but the other affirmative, there will be a syllogism, that the extreme is not present with a certain extreme, but if the contrary there will not be.

If indeed one be universal in respect to the middle, and the other particular, both being affirmative, syllogism is necessarily produced, whichever term be universal. For if R is present