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A Metainferential Solution to the Adoption Problem (Federico Pailos and Eduardo Barrio)

The Logic and Metaphysics Workshop will meet on April 5th from 4:15-6:15 (NY time) via Zoom for a talk by Federico Pailos and Eduardo Barrio (Buenos Aires).

Title: A Metainferential Solution to the Adoption Problem

Abstract: In ‘The Question of Logic’ (Kripke 2020) and “The Adoption Problem and the Epistemology of Logic” (Padró 2020), Kripke and Padró argue against the possibility of adopting an alternative logic. Without having already endorsed a logic, it is not possible to derive the consequences of an alternative system. In particular, without Modus Ponens in the metatheory, one could not adopt any inferential rule at all. This seems to cause trouble for logics like LP, that does not validate this rule. Modus Ponens is a self-governing rule that cannot be adopted and could not be rejected. This is connected with the problem of the tortoise reasoner (Scambler 2019) and the problem of the tortoise Logic (Priest 2021). In this talk, we offer a new solution. With the metainferential logic TS/LP it is possible to model metalogical Modus Ponens-like reasoning while still rejecting Modus Ponens.

Dualism about Generality (Martin Pleitz)

The Logic and Metaphysics Workshop will meet on March 22nd from 4:15-6:15 (NY time) via Zoom for a talk by Martin Pleitz (Münster).

This talk has been cancelled.

Title: Dualism about Generality

Abstract: In my talk I will motivate, outline, and apply a variant of first order predicate logic that can distinguish between two kinds of generality, which I call objectual generality and conceptual generality. To see the difference, compare the two general statements ‘Every human is a featherless biped’ and ‘Every human is a rational animal’. On a charitable understanding, the first sentence is about all humans past and present, as a subcollection of all particular objects currently accessible to us, while the second sentence is not about any particular object at all, but about the interaction of the concepts of being human and being a rational animal. Historically, the quantified sentences of predicate logic have been understood in either of the two ways. Frege understood them as expressing conceptual generalities; hence it was natural for him to call his predicate logic a “Concept Script”. Today, they are usually understood as objectual generalities, manifest both in the idea that a quantified sentence is like a conjunction (or disjunction) of its instances and in the current model theoretic orientation in semantics. But as we can find ourselves in a situation where we want to talk about both kinds of generality (and their interaction), it is worthwhile to develop the resources to express them within a single system. I will outline such a system that results from adding a second pair of quantifiers to regular first order predicate logic, and sketch applications to the notion of analyticity, natural kind predicates, and an ontological argument.

Belief Content and Rationality: Why Racist Beliefs Are Not Rational (Eric Bayruns Garcia)

The Logic and Metaphysics Workshop will meet on March 15th from 4:15-6:15 (NY time) via Zoom for a talk by Eric Bayruns Garcia (Cal State San Bernardino).

Title: Belief Content and Rationality: Why Racist Beliefs Are Not Rational

Abstract: I present a novel defense of the evidentialist thesis in the debate between epistemologists who defend this thesis and those who defend the moral encroachment thesis. Both sides of the moral encroachment-evidentialism debate suppose that the belief class of what I call seemingly-rational-racist beliefs obtains. I reject that this belief class of seemingly- rational-racist beliefs obtains on the basis that beliefs with this kind of content are false and evidentially unsupported. I submit that they are false and evidentially unsupported because of how the content of these beliefs relate to the social-linguistic practices and habits that compose racial injustice in the US and other similarly colonized societies. I diagnose that a problem with this debate is that both sides in this debate conceive of the content of race terms and beliefs that attribute negative features to Black, Indigenous and Latinx persons without considering how they function in a racially unjust society.

Two applications of Herzberger’s semantics (Hitoshi Omori)

The Logic and Metaphysics Workshop will meet on March 8th from 4:15-6:15 (NY time) via Zoom for a talk by Hitoshi Omori (Bochum).

Title: Two applications of Herzberger’s semantics

Abstract: In his paper “Dimensions of truth”, Hans Herzberger develops a semantic framework that captures both classical logic and weak Kleene logic through one and the same interpretation. The aim of this talk is to apply the simple idea of Herzberger to two kinds of many-valued semantics. This application will be led by the following two questions.

(i) Is de Finetti conditional a conditional?
(ii) What do CL, K3 and LP disagree about?

Note: This is a joint work with Jonas R. B. Arenhart (Santa Catarina).

The Easy Argument Against Noncontractive Logics Doesn’t Work (Shay Logan)

The Logic and Metaphysics Workshop will meet on March 1st from 4:15-6:15 (NY time) via Zoom for a talk by Shay Logan (Kansas State).

Title: The Easy Argument Against Noncontractive Logics Doesn’t Work

Abstract: The Easy Argument against noncontractivism is the argument that essentially amounts to pointing out that contraction is just repeating oneself. The purpose of this talk is to explain why the Easy Argument fails. I show first that the Easy Argument fails by being insufficiently precise, since there are many ways we can combine premises in an argument. After correcting for this, the Easy Argument then fails by being straightforwardly invalid. The premises required to correct for *this* failure, however, have controversial consequences. Altogether, it seems arguments against noncontractive logics, if there are any, will be Hard—not Easy—Arguments.

Substructural Solutions to the Semantic Paradoxes: a Dialetheic Perspective (Graham Priest)

The Logic and Metaphysics Workshop will meet on February 22nd from 4:15-6:15 (NY time) via Zoom for a talk by Graham Priest (CUNY).

Title: Substructural Solutions to the Semantic Paradoxes: a Dialetheic Perspective

Abstract: Over the last decade or so, a number of writers have argued for  solutions to the paradoxes of semantic self-reference which proceed by dropping some of the structural rules of inference, most notably Cut and/or Contraction.  In this paper, we will examine such accounts, with a particular eye on their relationship to more familiar dialetheic accounts.

Classical Counterpossibles (Patrick Girard)

The Logic and Metaphysics Workshop will meet on February 8th from 4:15-6:15 (NY time) via Zoom for a talk by Patrick Girard (Auckland).

Title: Classical Counterpossibles

Abstract: We present four classical theories of counterpossibles that combine modalities and counterfactuals. Two theories are anti-vacuist and forbid vacuously true counterfactuals, two are quasi-vacuist and allow counterfactuals to be vacuously true when their antecedent is not only impossible, but also inconceivable. The theories vary on how they restrict the interaction of modalities and counterfactuals. We provide a logical cartography with precise acceptable boundaries, illustrating to what extent nonvacuism about counterpossibles can be reconciled with classical logic.

Note: this is joint work with Rohan French (UC Davis) and Dave Ripley (Monash).

Spring 2021 Schedule

The Logic and Metaphysics Workshop will be meeting on Mondays from 4:15 to 6:15 (NY time) entirely online. The provisional schedule is as follows:

Feb 1. No Meeting

Feb 8. Patrick Girard, Auckland

Feb 15. No Meeting

Feb 22. Graham Priest, CUNY

Mar 1. Shay Logan, Kansas State

Mar 8. Hitoshi Omori, Bochum

Mar 15. Eric Bayruns Garcia, CalState San Bernardino

Mar 22. Martin Pleitz, Münster

Mar 29. No Meeting

Apr 5. Federico Pailos, Buenos Aires

Apr 12. William Nava, NYU

Apr 19. Vincent A. Peluce, CUNY

Apr 26. Rohan French, UC Davis

May 3. Graziana Ciola, Radboud Nijmegen

May 10. Filippo Casati, Lehigh

May 17. No Meeting

Essential Structure and Apt Causal Models (Jennifer McDonald)

The Logic and Metaphysics Workshop will meet on December 7th from 4:15-6:15 (NY time) via Zoom for a talk by Jennifer McDonald (CUNY).

Title: Essential Structure and Apt Causal Models

Abstract: A promising account of actual causation – the causal relation holding between two token events – uses the language of structural equation models (SEMs). Such an account says, roughly, that actual causation holds between two token events when there is a suitable model according to which (1) the two events occur; and (2) intervening on the model to change the value of the variable that represents the cause changes the value of the variable that represents the effect (Halpern & Pearl, 2005; Hitchcock, 2001; Weslake, 2015; Woodward, 2003). Of course, this calls for an account of when a model is suitable – or, apt. Although initially bracketed, this issue is increasingly pressing; in part due to the recently discovered problem of structural isomorphs (Hall 2007; Hitchcock 2007a; Blanchard and Schaffer 2017; Menzies 2017). This paper offers a unified analysis of two aptness requirements from the literature – those enjoining us to include essential structure and avoid unstable models. While successfully invoked by Blanchard and Schaffer (2017) to resolve the problem of structural isomorphs, these requirements are unilluminating as they stand. My paper synthesizes them into a single aptness requirement that, I claim, gets to the heart of what’s representationally required of a causal model for capturing actual causation.

ST and All That: Philosophical Issues

Following the recent workshop, Substructural Logic, Hierarchies Thereof, and Solutions to the Liar (October 30th, 2020), the Logic and Metaphysics Workshop and the Saul Kripke Center shall host ST and All That: Philosophical Issues, a roundtable discussion considering the philosophical implications of this technical work. The meeting will happen on Monday, December 14th, 2020, from 4:15 to 6:15 pm (NY time). Four panelists will speak for 15 minutes each addressing (at least) the following questions:

* What do we learn about the nature of logic from ST and its hierarchy?

* What do we learn about solutions to the liar from ST and its hierarchy?

There will then be an open discussion for all present. The panelists will be: Shay Logan (Kansas State), Federico Pailos (Buenos Aires), Dave Ripley (Monash), and Chris Scambler (NYU).

Talks will be on Zoom, and are open to all interested. A link will be sent out on the mailing lists of the Logic and Metaphysics Workshop and the Saul Kripke Center not later than the day before. People not on either of those lists who want to receive the link should email Graham Priest (priest DOT graham AT gmail DOT com). PLEASE FEEL FREE TO PASS ON THIS ANNOUNCEMENT.