Page:O. F. Owen's Organon of Aristotle Vol. 1 (1853).djvu/128



Chapter 14
A is contingent to every B, and B to every C, there will be a perfect syllogism, so that A is contingent to every C, which is evident from the definition, for thus we stated the universal contingent (to imply). So also if A is contingent to no B, but B to every C, (it may be concluded) that A is contingent to no C, for to affirm that A is contingent in respect of nothing to which B is contingent, this were to leave none of the contingents which are under B. But when A is contingent to every B, but B contingent to no C, no syllogism arises from the assumed propositions, but B C  being converted according to the contingent, the same syllogism arises as existed before, as since it happens that B is present with no C, it may also happen to be present with every C, which was shown before, wherefore if B may happen to every C, and A to every B, the same syllogism will again arise. The like will occur also if negation be added with the contingent (mode) to both propositions, I mean, as if A is contingent to no B, and B to no C, no syllogism arises through the assumed propositions, but when they are converted there will be the same as before. It is evident then that when negation is added to the minor extreme, or to both the propositions, there is either no syllogism, or an incomplete one, for the necessity (of consequence) is completed by conversion. If however one of the propositions be universal, and the other be assumed as particular, the universal belonging to the major extreme there will be a perfect syllogism, for if A is contingent to every B, but B to a certain C, A is also contingent to a certain C, and this is clear from the definition of universal contingent. Again, if A is contingent to no B, but B happens to be present with some C, it is necessary that A should happen not to be present with some C, since the