Declaring no dependence (Elise Crull)

The Logic and Metaphysics Workshop will meet on March 4th from 4:15-6:15 in-person at the Graduate Center (Room 7395) for a talk by Elise Crull (CUNY).

Title: Declaring no dependence

Abstract: Viable fundamental ontologies require at least one suitably stable, generic-yet-toothy metaphysical dependence relation to establish fundamentality. In this talk I argue that recent experiments in quantum physics using Page-Wootters devices to model global vs. local dynamics cast serious doubt on the existence of such metaphysical dependence relations when – and arguably, inevitably within any ontological framework – physical systems serve as the relata.

Semantic paradoxes as collective tragedies (Matteo Plebani)

The Logic and Metaphysics Workshop will meet on February 26th from 4:15-6:15 in-person at the Graduate Center (Room 7395) for a talk by Matteo Plebani (Turin).

Title: Semantic paradoxes as collective tragedies

Abstract: What does it mean to solve a paradox? A common assumption is that to solve a paradox we need to find the wrong step in a certain piece of reasoning. In this talk, I will argue while in the case of some paradoxes such an assumption might be correct, in the case of paradoxes such as the liar and Curry’s paradox it can be questioned.

Some model theory for axiomatic theories of truth (Roman Kossak)

The Logic and Metaphysics Workshop will meet on February 5th from 4:15-6:15 in-person at the Graduate Center (Room 7395) for a talk by Roman Kossak (CUNY).

Title: Some model theory for axiomatic theories of truth

Abstract: Tarski’s arithmetic is the complete theory of (N,+,x,Tr), where (N,+,x) is the standard model of arithmetic and Tr is the set of Gödel numbers of all true arithmetic sentences. An axiomatic theory of truth is an axiomatic subtheory of Tarski’s arithmetic. If (M,+,x,T) is a model of an axiomatic theory of truth, then we call T a truth class. In 1981, Kotlarski, Krajewski, and Lachlan proved that every completion of Peano’s arithmetic has a model that is expandable to a model  with a truth class T that satisfies all biconditionals in Tarski’s definition of truth formalized in PA. If T is such a truth class, it assigns truth values to all sentences in the sense of M, standard and nonstandard. The proof showed  that such truth classes can be quite pathological. For example, they may declare true some infinite disjunctions of the single sentence (0=1). In 2018, Enayat and Visser gave  a much simplified model-theoretic proof, which opened the door for further investigations of nonstandard truths, and many interesting new results by many authors appeared. I will survey some of them, concentrating on their model-theoretic content.

Spring 2024 Schedule

The Logic and Metaphysics Workshop will be meeting on Mondays from 4:15 to 6:15 unless otherwise indicated. Talks will be in-person only at the CUNY Graduate Center (Room 7395). The provisional schedule is as follows:

Feb 5. Roman Kossak (CUNY)

Feb 12. NO MEETING

Feb 19. NO MEETING

Feb 26. Matteo Plebani (Turin)

Mar 4. Elise Crull (CUNY)

Mar 11. Otávio Bueno (Miami)

Mar 18. Michał Godziszewski (Warsaw)

Mar 25. Dan Marshall (Lingnan)

Apr 1. Andrew Tedder (Vienna)

Apr 8. Asya Passinsky (CEU)

Apr 15. Jessica Collins (Columbia)

Apr 22. NO MEETING

Apr 29. Anandi Hattiangadi (Stockholm)

May 6. Lorenzo Rossi (Turin)

The logic of social choice (Rohit Parikh)

The Logic and Metaphysics Workshop will meet on December 11th from 4:15-6:15 (NY time) in-person at the Graduate Center (Room 4419) for a talk by Rohit Parikh (CUNY).

Title: The logic of social choice

Abstract: Logic entered social choice theory through Kenneth Arrow who was a student of the logician Alfred Tarski at City College of New York. Arrow’s impossibility result, which was axiomatic in nature, showed that there is no rational procedure to define the popular choice when there are three or more candidates. Arrow’s result led to a rich field. However, subsequent work has concentrated on what happens when voters face a slate of three or more candidates. There is not enough work on a theory of candidate slates themselves. Thus an election with just Donald Trump and Joe Biden is seen as unproblematic since there are only two candidates. The actual quality of the candidates does not matter. We will propose a method which depends on the actual quality of a candidate. Then it becomes a dominant game theoretic strategy for each party to nominate as good a candidate as possible. The goodness of a candidate is defined in terms of a dot product of two vectors: the candidate’s position and the position of a typical voter.

Use and mention in formal languages (James Walsh)

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

Title: Use and mention in formal languages

Abstract: Quine’s distinction between use and mention is one of the cornerstones of analytic philosophy. The distinction is typically motivated with examples from natural language, but Quine also applied the distinction to the formal languages studied in mathematical logic. I will argue that such expressions are not used in Quine’s sense, so the distinction cannot appropriately be applied to them. Accordingly, the standard practice of placing quotation marks around expressions of formal languages is incorrect. This technical point serves as a springboard for discussing the role that formal languages play in mathematical logic.

Truthmakers for modals: Meaning, truth, modals and quantifiers (Mircea Dumitru)

The Logic and Metaphysics Workshop will meet on November 27th from 4:15-6:15 (NY time) in-person at the Graduate Center (Room 4419) for a talk by Mircea Dumitru (Bucharest).

Title: Truthmakers for modals: Meaning, truth, modals and quantifiers

Abstract: First, I shall give a sketch of a general theory of truthmaking. Then, I shall raise some issues for the theory when it deals with modal language and point to some specific answers. In the remaining part I shall get into ramifications of this topic and discuss issues pertaining to meaning, truth and quantification in modal contexts and discourse.

Note: The subject of this talk was changed on Nov. 19, 2023. The previous title was “Truth with and without satisfaction”.

Vagueness and Frege (Marian Călborean)

The Logic and Metaphysics Workshop will meet on November 20th from 4:15-6:15 (NY time) in-person at the Graduate Center (Room 4419) for a talk by Marian Călborean (Bucharest).

Title: Vagueness and Frege

Abstract: A constant of Frege’s writing is his rejection of indeterminate predicates in natural language. I follow Frege’s remarks on vagueness from the early “Begriffsschrift” to his mature works, drawing parallels with contemporary theories of vagueness. I critically examine Frege’s arguments for the inconsistency of natural language and argue that the inability to accommodate vagueness and precision in his mature ontology and semantics is mainly due to heuristic rules which he took as essential, not to a deep problem in his fundamental apparatus.

Against zero-grounding (Alex Skiles)

The Logic and Metaphysics Workshop will meet on November 13th from 4:15-6:15 (NY time) in-person at the Graduate Center (Room 4419) for a talk by Alex Skiles (Rutgers).

Title: Against zero-grounding

Abstract: A number of philosophers believe that there is an intelligible distinction between ungrounded truths, which are not grounded in any truths at all, and zero-grounded truths, which are grounded, yet there are no truths that they are grounded in. Rather being a mere academic curiosity, these philosophers have also argued that the notion of zero-grounding can be put to serious metaphysical work. In this paper, we present two arguments against the intelligibility of zero-grounding, and then reject several attempts to make zero-grounding intelligible that have been suggested by its proponents.

Note: This is joint work with Tien-Chun Lo and Gonzalo Rodriguez-Pereyra.

On logics of acceptance and rejection (Alex Citkin)

The Logic and Metaphysics Workshop will meet on November 6th from 4:15-6:15 (NY time) in-person at the Graduate Center (Room 4419) for a talk by Alex Citkin (Metropolitan Telecommunications).

Title: On logics of acceptance and rejection

Abstract: In his book Formalization of Logic, Carnap suggested the following process of refutation: for any set of formulas Γ and any formula α, if Γ ⊢ α and α is rejected, reject Γ. Thus, in contrast to the Łukasiewicz’s approach to refutation, the predicate of rejection is defined on sets of formulas rather than just formulas. In addition to a predicate of rejection, we introduce a predicate of acceptance which is also defined on sets of formulas, and this leads us to constructing two-layered logical systems, the ground layer of which is a conventional deductive system (providing us with means for derivation), and the top layer having predicates of acceptance and rejection. In the case when the set of accepted formulas coincides with the set of theorems of the underlying logic and the set of rejected formulas coincides with the sets of non-theorems, we obtain a conventional deductive system. The predicate of acceptance can be non-adjunctive, and this allows us to use such systems as an alternative approach to defining Jaśkowski style discursive logics.

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