On the Fourth Figure

Abstract

260. In the fourth figure the moods that yield a conclusion are of necessity the moods that yield in the first figure because the premises are the same, except that the minor in this figure is the major in the first figure. It is clear that premises that satisfy syllogistic conditions will also satisfy the syllogistic conditions when their position has changed. For the conditions concerning the middle term, and the universality in one premise, and the affirmation in the other premise, do not change when the position of the premises has changed. But rather, what satisfied these conditions will also satisfy them when the major becomes the minor. All of this is self-evident. If <a syllogism> does not satisfy these conditions then it will not satisfy them when the major becomes the minor.