On Consequences By Virtue of Subalternation and Obversion

Abstract

56. If the universal affirmative simple <sentence> is true the particular affirmative simple <sentence> must be true with it in the same mode. For example, if a‘Ever a is b’ is true in a certain mode,a then it follows that’ some a is b’ will be true in the same mode. For since the sentence is affirmed of all a, it will be affirmed, according to the preceding,b of the particular that is subsumed under it in this sentence, i.e., some a. And the consequence will be in the same mode because we find in the particular the two conditions of the part and the whole that we stipulated in order to verify the consequence and to preserve it in the same mode: the linkage of the predicate does not vary because it is always linked to the same subject, and also’ some a’ is subsumed under ‘a’ and cannot be otherwise. In this manner it will become clear that the particular negative simple <sentence> will be true with the universal negative simple <sentence> in the same mode.