Author: Yale Weiss

Summer Logic Double Feature

The Saul Kripke Center is pleased to announce that Nils Kürbis (Bochum) and Heinrich Wansing (Bochum) will deliver talks on Wednesday, June 11th, 2025, at the CUNY Graduate Center (Room 9207). The talks are free and open to all.

Title (1): A Theory of Definite Descriptions for Modal Logic

Time (1): 2:00 to 3:00 pm

Speaker (1): Nils Kürbis (Bochum)

Abstract (1): I’ll present a theory of definite descriptions in positive free logic, where definite descriptions ‘the F’ are formalised as in the context of complete sentences ‘The F is G’ by a binary quantifier as Ix(F, G). Formalised in natural deduction or sequent calculus, the theory satisfies certain proof-theoretic requirements demanded by proof theoretic semantics. Thus the meaning of I can be taken to be defined by its rules of inference. Positive free logic has been fruitfully applied in quantified modal logic. So I’ll consider what happens when modal operators are added. It turns out that the semantic clauses for Ix(F, G) are exactly those of Fitting and Mendelsohn (First Order Modal Logic, 2nd edition, Springer 2023), except that they formalise ‘The F is G’ by the iota operator for ‘the’ and the lambda for predicate abstraction to mark scope. I’ll end the talk with a brief comparison between the two systems.

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Title (2): Solving a New Paradox of Deontic Logic (and a dozen other paradoxes) with RNmatrices for MC-based Modal Logics

Time (2): 3:00 to 4:00 pm

Speaker (2): Heinrich Wansing (Bochum) [joint work with Daniel Skurt (Bochum)]

Abstract (2): In this paper, we present RNmatrices (restricted non-deterministc matrices) for normal and non-normal modal expansions of the material connexive logic MC. We introduce and solve a paradox of deontic logic that to the best of our knowledge has not yet been been discussed in the literature and that justifies the use of a connexive, and actually hyperconnexive, non-modal base logic.

Beyond the Outline: A Celebration of Fifty Years of Kripke on Truth

To mark the 50th anniversary of the first publication of Saul Kripke’s influential paper, “Outline of a Theory of Truth”, the Saul Kripke Center will host a major international conference on theories of truth at the CUNY Graduate Center in New York City on November 20 and 21, 2025. Conference speakers include:

    1. Eduardo Barrio (Buenos Aires)
    2. Hartry Field (NYU)
    3. Michael Glanzberg (Rutgers)
    4. Leon Horsten (Konstanz)
    5. Carlo Nicolai (KCL)
    6. Lavinia Picollo (NUS)
    7. Graham Priest (CUNY)
    8. Lorenzo Rossi (Turin)
    9. James Walsh (NYU)
The conference will be organized as an exclusively in-person event. Attendance is open, without registration or cost, to anyone who is interested (Building Entry Policy). The schedule of talks and further information will be released closer to the event.

New Book: Saul Kripke on Modal Logic

A new book celebrating Saul Kripke’s singular contributions to modal logic, Saul Kripke on Modal Logic, has just been published by Springer. It was edited by Yale Weiss and Romina Birman.

Saul Kripke on Modal Logic (Cover)

The volume features two previously unpublished pieces by Saul Kripke, a brief intellectual biography recounting the story of how Kripke became involved in modal logic, and a number of contributions dealing with the cutting edge of modal logic.

The Myth of the Ungiven

The Saul Kripke Center is pleased to announce that Kit Fine (Silver Professor and University Professor of Philosophy and Mathematics at NYU) will deliver the 6th Saul Kripke Lecture on October 31st, 2024, from 4:00 to 6:30 pm. The talk is free and open to all, and will be held in-person only at the CUNY Graduate Center (Room C198).

Title: The Myth of the Ungiven

Abstract: The notion of a borderline case has been thought to be central to our understanding of vagueness. I shall argue that there is no intelligible notion that can play this role and that an alternative framework for understanding vagueness needs to be found.

Modal definability and Kripke’s theory of truth

The Saul Kripke Center is pleased to announce that James Walsh (Assistant Professor, Philosophy, NYU) will deliver a talk on Friday, May 10th, 2024, from 4:15 to 6:15 pm at the CUNY Graduate Center (Room 9207). The talk is free and open to all.

Title: Modal definability and Kripke’s theory of truth

Abstract: In Outline of a Theory of Truth, Kripke introduces some of the central concepts of the logical study of truth and paradox. He informally defines some of these–such as groundedness and paradoxicality–using modal locutions. We introduce a modal language for regimenting Kripke’s informal definitions and characterize the modally definable sets. Though groundedness and paradoxicality are expressible in the modal language, we prove that intrinsicality–which Kripke emphasizes but does not define modally–is not.

Zoom Access: please follow this link.

New Visiting Scholar: Lorenzo Rossi

Lorenzo Rossi (DPhil, University of Oxford), assistant professor at the University of Turin, joins the Saul Kripke Center as a Visiting Research Scholar through June 27, 2024, under the auspices of the PLEXUS program. He works on topics at the intersection of logic, epistemology, the philosophy of language, and the philosophy of mathematics, and more specifically on formal theories of truth, vagueness, indicative conditionals, and quantifiers.