The Provability of Consistency (Sergei Artemov)

The Logic and Metaphysics Workshop will meet on November 4th from 4:15-6:15 in room 7314 of the CUNY Graduate Center for a talk by Sergei Artemov (CUNY).

Title: The Provability of Consistency

Abstract: We revisit the foundational question “Can consistency of a theory T be established by means of T?” The usual answer “No, by Gödel’s Second Incompleteness Theorem” is based on two assumptions:

1. Gödel’s internalized consistency formula is the only way to represent consistency.
2. Any contentual reasoning within T internalizes as a formal derivation in T.

We show that already for Peano arithmetic PA both of these assumptions are false: (1) does not cover such legitimate mode of presentation as schemes (think of the Induction scheme), (2) fails for schemes. Based on these observations, we offer a proof of PA-consistency by means of PA and discuss its potential impact.

Benacerraf’s Non-Problem (Barbara Gail Montero)

The Logic and Metaphysics Workshop will meet on October 28th from 4:15-6:15 in room 7314 of the CUNY Graduate Center for a talk by Barbara Gail Montero (CUNY).

Title: Benacerraf’s Non-Problem

Abstract: Research in philosophy of mathematics over roughly the past half century can be understood, to a large degree, as a series of responses to what is commonly known as the Benacerraf problem: Given the abstract nature of mathematical entities, how can we come to have mathematical knowledge? How are we, in Benacerraf’s words,  “to bridge the chasm. . . between the entities that form the subject matter of mathematics and the human knower?” In this talk, I aim to share with you some of the reasons why I think that Benacerraf’s problem—as he presents it and as Field restates it—just may be nothing to worry about. ​

 

The Buddha versus Popper: When to Live? (Rohit Parikh)

The Logic and Metaphysics Workshop will meet on October 21st from 4:15-6:15 in room 7314 of the CUNY Graduate Center for a talk by Rohit Parikh (CUNY).

Title: The Buddha versus Popper: When to Live?

Abstract: We discuss two approaches to life: presentism and futurism. The first one, which we are identifying with the Buddha, is to live in the present and not to allow the future to hinder us from living in the ever present now. The second one, which we will identify with Karl Popper, is to think before we act, and act now for a better future. We will discuss various aspects of presentism and futurism, such as Ruth Millikan’s Popperian animal, the psychologist Howard Rachlin’s social and temporal discounting, and even the popular but controversial idea, YOLO (you live only once). The purpose of this talk is to contrast one with the other. The central question of ethics is: How should one live? Our variation on that question is: When should one live? We conjecture that the notion of flow, developed by Csikszentmihalyi, may be a better optimal choice between these two positions.

This work, which is joint with Jongjin Kim, is to appear in the Journal of Buddhist Ethics.

 

Explanation and Modality: On Why The Swampman Is Still Worrisome to Teleosemanticists (Dongwoo Kim)

The Logic and Metaphysics Workshop will meet on October 7th from 4:15-6:15 in room 7314 of the CUNY Graduate Center for a talk by Dongwoo Kim (CUNY).

Title: Explanation and Modality: On Why The Swampman Is Still Worrisome to Teleosemanticists

Abstract: Many have thought that Davidson’s Swampman scenario offers a serious problem to teleosemantics. For it appears to be possible from the scenario that there are completely ahistorical creatures with beliefs, and this apparent possibility contradicts the theory. In a series of papers (2001, 2006, 2016), Papineau argues that the Swampman scenario is not even the start of an objection to teleosemantics as a scientific reduction of belief. It is against this claim that I want to argue here. I shall argue that the explanatory power of teleosemantics rests on two conceptual pillars, namely success semantics and the etiological conception of biological function, and that the Swampman scenario questions the adequacy of the foundational conceptual commitments. Along the way, some general connection between explanation and modality will be developed that sheds a new light on Kripke’s analysis of necessary a posteriori propositions. The conclusion will be that teleosemanticists should tackle the Swampman objection head on.

 

Existence, Verbal Disputes and Equivocation (Alessandro Rossi)

The Logic and Metaphysics Workshop will meet on September 23rd from 4:15-6:15 in room 7314 of the CUNY Graduate Center for a talk by Alessandro Rossi (St Andrews).

Title: Existence, Verbal Disputes and Equivocation

Abstract: Noneism is the theory according to which some things do not exist. Following an established convention, I will call allism the negation of noneism (every thing exists). Lewis [1990] and, more recently, Woodward [2013] argued that the allism/noneism dispute turns on an equivocation about the meaning of ‘exists’ and would thereby be merely verbal. These arguments have been attacked by Priest [2005, 2011, 2013], who took the dispute to be genuine. In this paper, I will present two new arguments for the genuineness of the allism/noneism dispute. The first appeals to a recent version of logical pluralism defended by Kouri Kissel [Forth]: the two parties could be seen as engaging in a metalinguistic negotiation, that is, a normative disagreement about which meaning of ‘exists’ is best suited for a certain domain of discourse. Secondly, Williamson [1987] indicated a proof-theoretic criterion the two sides should meet in order for their dispute to count as genuine: they must share enough rules of inference governing ‘exist’ to characterise it up to logical equivalence. This challenge, I argue, can be met.

 

Anti-Exceptionalism and Explanations in Logic (Ole Hjortland and Ben Martin)

The Logic and Metaphysics Workshop will meet on September 16th from 4:15-6:15 in room 7314 of the CUNY Graduate Center for a talk by Ole Hjortland and Ben Martin (Bergen).

Title: Anti-Exceptionalism and Explanations in Logic

Abstract: According to logical anti-exceptionalism we come to be justified in believing logical theories by similar means to scientific theories. This is often explained by saying that theory choice in logic proceeds via abductive arguments (Priest, Russell, Williamson, Hjortland). Thus, the success of classical and non-classical theories of validity are compared by their ability to explain the relevant data. However, as of yet there is no agreed upon account of which data logical theories must explain, and subsequently how they prove their mettle. In this paper, we provide a non-causal account of logical explanation, and show how it can accommodate important disputes about logic.

 

Temporal ‘de re’ Attitudes (Yael Sharvit)

The Logic and Metaphysics Workshop will meet on September 9th from 4:15-6:15 in room 7314 of the CUNY Graduate Center for a talk by Yael Sharvit (UCLA).

Title: Temporal ‘de re’ Attitudes

Abstract: A sensible approach to the semantics of tense says that present tense and past tense “refer” to the evaluation time and to some pre-evaluation time, respectively. Indeed, this seems to be the case in unembedded sentences (e.g., Mary is thirty-five, Mary was thirty-five). But embedded tenses seem to misbehave: (1) does not express the proposition that two months prior to s* (= the speech time) Joseph was sure about the truth of [Mary is currently thirty-five]; this proposition is expressed by (2). Assuming that tenses are indexical expressions does not automatically solve the problem, since (1) does not express the proposition that two months prior to s* Joseph was sure about the truth of [Mary will be thirty-five at s*] either; that proposition is expressed by (3). (In addition, (2) does not express the proposition that two months prior to s* Joseph was sure about the truth of [Mary will be thirty-five at some s** < s*].) In fact, (1) roughly expresses the proposition that two months prior to s* Joseph was sure about the truth of [Mary is currently thirty-five and will still be thirty-five at s*] (Smith (1978), Enc (1987)). Indeed, unlike (1), (1′) is usually quite odd (presumably because most speakers presuppose that, like them, Joseph can accept that Mary is thirty-five for a period of two – sometimes even twelve – months, but not that she is thirty-five for a period of twenty months). To explain why the embedded past in (2) “refers” to the embedded evaluation time, and why the embedded present in (1)/(1’) “refers” to a time much larger than that, we assume, with Abusch (1997), that these embedded tenses are indexical expressions governed by general constraints on ‘de re’ attitude reports, including – crucially – the Upper Limit Constraint. Expanding on Abusch (1997) and Percus (2013), we derive the Upper Limit Constraint itself from general principles as well.

(1) Two months ago, Joseph was sure that Mary is thirty-five.
(2) Two months ago, Joseph was sure that Mary was thirty-five.
(3) Two months ago, Joseph was sure that Mary would now be thirty-five.
(1′)  Twenty months ago, Joseph was sure that Mary is thirty-five.

 

Fall 2019 Schedule

The Logic and Metaphysics Workshop will be meeting on Mondays from 4:15 to 6:15 in room 7314 of the Graduate Center, CUNY (365 5th Avenue). The provisional schedule is as follows:

Sep 2. GC CLOSED. NO MEETING

Sep 9. Yael Sharvit, UCLA

Sep 16. Ole Hjortland and Ben Martin, Bergen

Sep 23. Alessandro Rossi, St Andrews

Sept 30. GC CLOSED. NO MEETING

Oct 7. Dongwoo Kim, CUNY

Oct 14. GC CLOSED. NO MEETING

Oct 21. Rohit Parikh, CUNY

Oct 28. Barbara Montero, CUNY

Nov 4. Sergei Artemov, CUNY

Nov 11. Martin Pleitz, Hamburg

Nov 18. Matias Bulnes, CUNY

Nov 25. Vincent Peluce, CUNY

Dec 2. Jessica Wilson, Toronto

Dec 9. Mark Colyvan, Sydney

The Perception of Time in Intuitionistic Arithmetic (Vincent Peluce)

The Logic and Metaphysics Workshop will meet on May 20th from 4:15-6:15 in room 7314 of the CUNY Graduate Center for a talk by Vincent Peluce (CUNY).

Title: The Perception of Time in Intuitionistic Arithmetic

AbstractIn L.E.J. Brouwer’s first act of intuitionism, the subject’s perception of time is put forth as the foundation on which arithmetic will be built. According to Brouwer, proper intuitionistic arithmetic, as with the rest of intuitionistic mathematics, is not tied to any particular formal system. When we try to axiomatically approximate an intuitionistic arithmetical system, we are faced with the problem of incorporating the subject and their perception into the axiom system itself. We discuss some unsatisfactory responses to this problem and then offer a solution.

Composition as Identity: A New Approach (Martina Botti)

The Logic and Metaphysics Workshop will meet on May 13th from 4:15-6:15 in room 7314 of the CUNY Graduate Center for a talk by Martina Botti (Columbia).

Title: Composition as Identity: A New Approach

AbstractI argue that the debate on composition as identity – the thesis that any composite object is identical to its parts – is deadlocked because both the defenders and the detractors of the claim have so far defended and criticized respectively something that is not composition as identity. After having made clear how composition as identity should properly be understood, I will set forth a new strategy to defend it.