The Logic and Metaphysics Workshop will meet on February 3rd from 4:15-6:15 in room 7395 of the CUNY Graduate Center for a talk by Hartry Field (NYU).

Title: The Power of Naive Truth

Abstract: While non-classical theories of truth that take truth to be transparent have some obvious advantages over any classical theory that evidently must take it as non-transparent, several authors have recently argued that there’s also a big disadvantage of non-classical theories as compared to their “external” classical counterparts: proof-theoretic strength. Some of them have concluded that this gives a decisive advantage to classical logic theories.  Williamson has argued this too. While conceding the relevance of proof-theoretic strength to the choice of logic, I will argue that there is a natural way to beef up extant internal theories so as to remove their proof-theoretic disadvantage. Given this, the resulting internal theories should seem preferable to their external counterparts.

The Logic and Metaphysics Workshop will meet on February 10th from 4:15-6:15 in room 7395 of the CUNY Graduate Center for a talk by Melissa Fusco (Columbia).

Title: A Deontic Logic for Two Paradoxes of Deontic Modality

Abstract: In this paper, we take steps towards axiomatizing the two dimensional deontic logic in Fusco (2015), which validates a form of free choice permission (von Wright 1969, Kamp 1973; (1) below) and witnesses the nonentailment known as Ross’s Puzzle (Ross 1941; (2) below).

(1) You may have an apple or a pear ⇒ You may have an apple, and you may have a pear.

(2) You ought to post the letter = ̸⇒ You ought to post the letter or burn it.

Since <>(p or q) = (<>p ∨ <>q) and [ ](p) ⇒ [ ](p ∨ q) are valid in any normal modal logic – including standard deontic logic – the negations of (1)-(2) are entrenched in modal proof systems. To reverse them without explosion will entail excavating the foundations of the propositional tautologies. The resulting system pursues the intuition that classical tautologies involving disjunctions are truths of meaning, rather than propositional necessities. This marks a departure from the commitments the propositional fragment of a modal proof system is standardly taken to embody.

Note: This is joint work with Arc Kocurek (Cornell).

The Logic and Metaphysics Workshop will be meeting on Mondays from 4:15 to 6:15 in room 7395 of the Graduate Center, CUNY (365 5th Avenue). The provisional schedule is as follows (* indicates a change):

Feb 3. Hartry Field, NYU

Feb 10. Melissa Fusco, Columbia

Feb 17. NO MEETING (GC CLOSED)

Feb 24. Dongwoo Kim, GC (CUNY)

Mar 2. Alex Citkin, Metropolitan Telecommunications

Mar 9. Antonella Mallozzi, Providence College

Mar 16. David Papineau, GC (CUNY)*

Mar 23. Jenn McDonald, GC (CUNY)

Mar 30. Mircea Dimitru, Bucharest*

Apr 6. Eoin Moore, GC (CUNY)

Apr 13. SPRING RECESS (NO MEETING)

Apr 20. Michał Godziszewski, Munich

Apr 27. Michael Glanzberg, Rutgers

May 4. Matteo Zichetti, Bristol

May 11. Lisa Warenski, GC (CUNY)

May 18. PROBABLY NO MEETING