| (major) | S ⎯ P, | contradictory of (3) | |
| (minor) | S ⎯ M, | (1) | |
| (conclusion) | ∴ | (M ⎯ P)ʹ. | contradictory of (2) |
The special rules of figure 1 are
| minor | affirmative, |
| major | universal, |
that is, (1) must be affirmative, (2) must be universal.
In figure 2, (2) is the major, and the contradictory of (1) is the conclusion. Therefore, in figure 2 we must have the rules,—
| major | universal, |
| conclusion | negative [and hence one premiss negative]. |
In figure 3, (1) is the minor, and the contradictory of (2) is the conclusion. Therefore, in figure 3 we must have the rules,—
| minor | affirmative, |
| conclusion | particular. |
Thus the special rules of figures 2 and 3 are shewn to be deducible from the special rules of figure 1. We might equally 336 well start from the special rules of figure 2 or of figure 3 and deduce the rules of the two other figures.[365]
[365] The complete rules for the antilogisms of the first three figures, as given at the end of section [266], are (a) first proposition universal, (b) second proposition affirmative, (c) third proposition opposite in quality to the first, and (unless it is strengthened) opposite in quantity to the second. These rules replace all general rules.