The Logic and Metaphysics Workshop will meet on November 5th from 4:15-6:15 in room 6494 of the CUNY Graduate Center for a talk by Melissa Fusco (Columbia).

Title: Agential Free Choice

Abstract: The Free Choice effect—whereby ♢(p or q) seems to entail both ♢p and ♢q—has long been described as a phenomenon affecting the deontic modal “may”. This paper presents an extension of the semantic account of deontic free choice defended in Fusco (2015) to the agentive modal “can”, the “can” which, intuitively, describes an agent’s powers. I begin by sketching a model of inexact ability, which grounds a modal approach to agency (Belnap & Perloff, 1998; Belnap et al., 2001) in a Williamson (1992, 2014)-style margin of error. A classical propositional semantics combined with this framework can reflect the intuitions highlighted by Kenny (1976)’s much-discussed dartboard cases, as well as the counterexamples to simple conditional views recently discussed by Mandelkern et al. (2017). In §3, I substitute for classical disjunction an independently motivated generalization of Boolean join—one which makes the two diagonally, but not generally, equivalent—and show how it extends free choice inferences into a simple object language.

The Logic and Metaphysics Workshop will meet on October 29th from 4:15-6:15 in room 6494 of the CUNY Graduate Center for a talk by Boris Kment (Princeton).

Title: Ground and Paradox

Abstract: This paper discusses a cluster of interrelated paradoxes, including the semantic and property-theoretic paradoxes (such as the paradox of heterologicality), as well as the set-theoretic paradoxes and the Russell-Myhill paradox. I argue that an independently motivated theory of metaphysical grounding provides philosophically satisfying treatments of these paradoxes. It yields as corollaries a version of the iterative conception of set and an analogous solution to Russell-Myhill. Moreover, it generates a paracomplete solution to the property-theoretic paradoxes. This solution also applies to the semantic paradoxes, which can be subsumed under the property-theoretic ones. The treatment of the property-theoretic paradoxes has structural similarities to Kripke’s approach to the Liar, and it promises to resolve the main outstanding difficulties for this position, such as revenge cases and the problem of adding a conditional with a sufficiently strong logic.