Category: Fall 2023

The Logic and Metaphysics Workshop will meet on October 16th from 4:15-6:15 (NY time) in-person at the Graduate Center (Room 4419) for a talk by Yale Weiss (CUNY).

Title: Maximal deontic logic

Abstract: The worlds accessible from a given world in Kripke models for deontic logic are often informally glossed as ideal or perfect worlds (at least, relative to the base world). Taking that language seriously, a straightforward but nonstandard semantic implementation using models containing maximally good worlds yields a deontic logic, MD, considerably stronger than that which most logicians would advocate for. In this talk, I examine this logic, its philosophical significance, and its technical properties, as well as those of the logics in its vicinity. The principal technical result is a proof that MD is pretabular (it has no finite characteristic matrix but all of its proper normal extensions do). Along the way, I also characterize all normal extensions of the quirky deontic logic D4H, prove that they are all decidable, and show that D4H has exactly two pretabular normal extensions.

The Logic and Metaphysics Workshop will meet on October 2nd from 4:15-6:15 (NY time) in-person at the Graduate Center (Room 4419) for a talk by Brett Topey (Salzburg).

Title: Whence admissibility constraints? From inferentialism to tolerance

Abstract: Prior’s invented connective ‘tonk’ is sometimes taken to reveal a problem for certain inferentialist approaches to metasemantics: according to such approaches, the truth-theoretic features of our expressions are fully determined by the rules of inference we’re disposed to follow, but admitting the ‘tonk’ rules into a language would lead to intuitively absurd results. Inferentialists tend to insist that they can avoid these results: there are constraints on what sets of inference rules can be admitted into a language, the story goes, and the rules governing disruptive expressions like ‘tonk’ are defective and so illegitimate. I argue, though, that from an inferentialist perspective, there’s no genuine sense in which rules like the ‘tonk’ rules are defective; those who endorse the relevant sort of inferentialism turn out to be committed to Carnap’s principle of tolerance. I then sketch an argument to the effect that this, despite appearances, isn’t a problem for inferentialism.

The Logic and Metaphysics Workshop will meet on September 18th from 4:15-6:15 (NY time) in-person at the Graduate Center (Room 4419) for a talk by Will Nava (NYU).

Title: Non-classicality all the way up

Abstract: Nearly all non-classical logics that have been studied admit of classical reasoning aboutthem. For example, in the logic K3, A or not-A is not a valid schema. However, ‘A or not-A’ is K3-valid or not K3-valid—this is, in some sense, a valid claim. In this talk, I introduce a simple framework for thinking about the logic of a given logic. This allows for a measure of the non-classicality of a logic—one on which almost all familiar non-classical logics are of the lowest grade of non-classicality. I’ll then discuss some strategies for generating and theorizing logics of higher grades of non-classicality, as well as some motivation for taking these logics seriously.

The Logic and Metaphysics Workshop will meet on September 11th from 4:15-6:15 (NY time) in-person at the Graduate Center (Philosophy Program Thesis Room in 7113) for a talk by Francesco Paoli (Cagliari).

Title: Logical metainferentialism

Abstract: Logical inferentialism is the view that the meaning of the logical constants is determined by the rules of inference that govern their behaviour in proofs – in particular, sequent calculus proofs, according to the preferences of several recent authors. When it comes to the nuts and bolts, however, the view is tenable only if certain aspects – concerning e.g. harmony criteria for rules, normal forms, or proof-theoretic validity – are clarified. Sequent calculus inferentialists generally do so in terms of proofs from axioms, not of derivations from assumptions. Although the merits of this approach are already debatable in traditional settings, recent work on sequent calculi without Identity or Cut has revealed further shortcomings. Logical metainferentialism revises inferentialism in this more general perspective. In this talk, we will sketch the basics of this view and argue that, from this vantage point, the claim that LP is the “One True Logic” may appeal even to the inferentialistically inclined logician.

The Logic and Metaphysics Workshop will be meeting on Mondays from 4:15 to 6:15 (NY time) unless otherwise indicated. Talks will be in-person only at the CUNY Graduate Center (Room 4419). The provisional schedule is as follows:

Sep 4. NO MEETING

Sep 11. Francesco Paoli (Cagliari)

Sep 18. Will Nava (NYU)

Sep 25. NO MEETING

Oct 2. Brett Topey (Salzburg)

Oct 9. NO MEETING

Oct 16. Yale Weiss (CUNY)

Oct 23. Melissa Fusco (Columbia)

Oct 30. Brad Armour-Garb (SUNY Albany)

Nov 6. Alex Citkin (Independent Scholar)

Nov 13. Alex Skiles (Rutgers)

Nov 20. Marian Călborean (Bucharest)

Nov 27. Mircea Dumitru (Bucharest)

Dec 4. James Walsh (NYU)

Dec 11. Rohit Parikh (CUNY)