www.TheLogician.net © Avi Sion - all rights reserved
© Avi Sion
All rights reserved
© Avi Sion, 2005. All rights reserved.
R. Ishmael’s Rule No. 1, concerning a-fortiori argument, can be represented by a triangular star, at the center of which is the middle item (R) through which the three other items, P, Q, and S are related to each other.
The a-fortiori argument may also be represented, with reference to the comparative propositions that underlie it, as ordering items P, Q, and S, according to their position in a common continuum R:
Note that the four figures of a-fortiori should not be confused with the
four of syllogism they imply, which are, in the order shown: the fourth, third,
first and second figures.