The Logic and Metaphysics Workshop will meet on October 3rd from 4:15-6:15 (NY time) in-person at the Graduate Center (Room 7314) for a talk by Yale Weiss (CUNY).
Title: The best of all possible Leibnizian completeness theorems
Abstract: Leibniz developed several arithmetical interpretations of the assertoric syllogistic in a series of papers from April 1679. In this talk, I present his most mature arithmetical semantics. I show that the assertoric syllogistic can be characterized exactly not only in the full divisibility lattice, as Leibniz implicitly suggests, but in a certain four-element sublattice thereof. This refinement is also shown to be optimal in the sense that the assertoric syllogistic is not complete with respect to any smaller sublattice using Leibniz’s truth conditions.