if the contingently not present be changed, there will again be the first figure by conversion. If however one term be universal but the other particular, when they are so, as in the case of simple inesse, there will, and will not, be a syllogism; for let A be contingently present with every C, and B present with a certain C, there will again be the first figure by conversion of the particular proposition, since if A is contingent to every C, and C to a certain B, A is also contingent to a certain B, and in like manner if the universal be joined to B C. This also will be produced in a similar way if A C be negative, but B C affirmative, for again we shall have the first figure by conversion, if however both are negative, the one universal and the other particular, by the assumed propositions there will not be a syllogism, but there will be when they are converted as before. Lastly, when both are indefinite or particular, there will not be a syllogism, for A must necessarily be present with every and with no B, let the terms de inesse be "animal," "man," "white," and de non-inesse "horse," "man," "white," the middle term "white."
Chapter 21
If however one premise signifies the inesse, but the other the contingent, the conclusion will be that a thing is contingent to, and not that it is present with (another), and there will be a syllogism, the terms subsisting in the same manner as the previous ones. For, first, let them be affirmative, and let A be in every C, but B contingent with every C; B C then being converted there will be the first figure, and the conclusion will be that A is contingently present with a certain B, for when one premise in the first figure signifies the contingent, the conclusion also was contingent. In like manner if the proposition B C be of the simple inesse, but the proposition
