The Logic and Metaphysics Workshop will meet on November 25th from 4:15-6:15 in room 7314 of the CUNY Graduate Center for a talk by Vincent Alexis Peluce (CUNY).
Title: Memory and Intuitionistic Logic
Abstract: L.E.J. Brouwer writes, “people try by means of sounds and symbols to originate in other people copies of the mathematical constructions and reasonings which they have made themselves; by the same means they try to aid their own memory. In this way the mathematical language comes into being, and as its special case the language of logical reasoning” (1907). More is left to be said, however, about the relation between the Brouwerian subject and logical language. In this talk we discuss the usual account of this relation and some problems with that view. We then propose an alternative.
The Logic and Metaphysics Workshop will meet on November 18th from 4:15-6:15 in room 7314 of the CUNY Graduate Center for a talk by Matías Bulnes (CUNY).
Title: An Unorthodox Solution to the Hintikka-Kripke Problem
Abstract: The Hintikka-Kripke problem consists in reconciling Hintikka’s semantics for doxastic operators and Kripke’s semantics for alethic operators. The problem arises from their treatment of identity. While the necessity of identities was one of the main innovations of Kripke’s semantics, Hintikka needs identities to be contingent to explain the opacity of doxastic operators. Yet alethic and doxastic operators are combined effortlessly in everyday discourse. In the talk, I will first discuss various attempts at reconciliation within the orthodoxy about opacity, and raise objections to them. Then, I will propose an unorthodox idea: rather than thinking of doxastic operators as introducing new possible worlds with different identities, think of them as introducing new logical spaces with different domains of objects. This achieves reconciliation by circumscribing the necessity of identities to the logical space of each agent. To assess this idea viz-a-viz its competitors, we will have to reexamine some fundamental concepts of the problem of opacity, such as the concepts of language and semantics.
The Logic and Metaphysics Workshop will meet on November 11th from 4:15-6:15 in room 7314 of the CUNY Graduate Center for a talk by Martin Pleitz (Hamburg).
Title: Talking about Reification
Abstract: Reification is the systematic association of a non-object with an object that encodes it. Therefore the reificationist must be a trans-objectist – i.e., anyone who thinks that there are instances of reification must also think that some items are not objects. As exemplified by Frege’s puzzle of the concept horse, non-objects and reification are notoriously difficult to talk about. Therefore I will begin my presentation by outlining a formal language that enables the trans-objectist and the reificationist to speak in a way that is not self-undermining. I will go on and employ the framework to give a uniform diagnosis of the set theoretic and semantic paradoxes in terms of static reification that is an alternative to Graham Priest’s Inclosure Schema, and sketch how dynamic reification can provide a uniform solution to the paradoxes as well as a general account of the constitution of abstract objects. In order to achieve this it will be crucial to import some tools of Procedural Postulationism, a dynamic account of the ontology of mathematics developed by Kit Fine.
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.
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 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.
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.
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  and, more recently, Woodward  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  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.
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.
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.