Page:O. F. Owen's Organon of Aristotle Vol. 1 (1853).djvu/144

 universally, or partially, still the demonstration will be the same, and by the same terms, yet when the affirmative is contingent, but the negative simple, there will be a syllogism. For let A be assumed present with no B, but contingent with every C, then by conversion of the negative, B will be present with no A, but A is contingent to every C, therefore there is a syllogism in the first figure, that B is contingent to no C. So also if the negative be added to C; but if both propositions be negative, and one signifies the simple, but the other the contingent non-inesse, from these assumed propositions nothing necessary is inferred, but the contingent proposition being converted, there is a syllogism, wherein B is contingently present with no C, as in the former, for again there will be the first figure. If, however, both propositions be assumed