Calendar

n his seminal work Counterfactuals, David Lewis presents a family of systems of conditional logic—his V-family—which includes both his preferred logic of counterfactuals (VC/C1) and Stalnaker’s conditional logic (VCS/C2). Graham Priest posed the problem of finding systems of (labeled) tableaux for logics from Lewis’s V-family in his Introduction to Non-Classical Logic (2008, p. 93). In this talk, I present a solution to this problem: sound and complete (labeled) tableaux for Lewis’s V-logics. Errors and shortcomings in recent work on this problem are identified and corrected (especially close attention is given to a recent paper by Negri and Sbardolini, whose approach anticipates my own). While most of the systems I present are analytic, the tableaux I give for Stalnaker’s VCS and its extensions make use of a version of the Cut rule and, consequently, are non-analytic. I conjecture that Cut is eliminable from these tableaux and discuss problems encountered in trying to prove this.

The Logic and Metaphysics Workshop will be meeting on Mondays from 4:15 to 6:15 in room 6494 of the Graduate Center, CUNY (365 5th Avenue). The (provisional) schedule is as follows:

Sep 17. Sander Breckers, Utrecht

Sep 24. Hanoch Ben-Yami, CEU

Oct 1. Otavio Bueno, Miami

Oct 8. GC CLOSED. NO MEETING

Oct 15. Alfredo Freire, Campinas

Oct 22. Yale Weiss, GC

Oct 29. Boris Kment, Princeton

Nov 5. Melissa Fusco, Columbia

Nov 12. Amy Seymour, Fordham

Nov 19. Andrew Tedder, UConn

Nov 26. Justin Bledin, Johns Hopkins

Dec 3. Suki Finn, Southampton

Dec 10. Byong Yi, Toronto

Since the discovery of the Loweinheim-Skolem theorem, it has been largely held that there is no purely formal way of fixing a model for any first order theory. Because of this, many have focused on having a relative account of models, establishing the expressive power of one model in its ability to internalize models for other theories. One can, for instance, define a plurality of models for PA from a given model for ZF, and this may be understood as evidence for the ontology of arithmetics being reducible to the ontology of set theory. In this presentation, I argue that a close attention to what it means to reduce an ontology shows that methods of reduction are generally not neutral and make it possible for weaker models to reduce stronger ones. For this, I analyze the known model-theoretical reduction of NBG into ZF proved by Novak, showing that a more demanding method makes it impossible for ZF to internalize NBG. We finish this presentation by showing how this view, together with some technical results, provide a positive account in defense of the multiversalist perspective on set theory.

The Logic and Metaphysics Workshop will be meeting on Mondays from 4:15 to 6:15 in room 6494 of the Graduate Center, CUNY (365 5th Avenue). The (provisional) schedule is as follows:

Sep 17. Sander Breckers, Utrecht

Sep 24. Hanoch Ben-Yami, CEU

Oct 1. Otavio Bueno, Miami

Oct 8. GC CLOSED. NO MEETING

Oct 15. Alfredo Freire, Campinas

Oct 22. Yale Weiss, GC

Oct 29. Boris Kment, Princeton

Nov 5. Melissa Fusco, Columbia

Nov 12. Amy Seymour, Fordham

Nov 19. Andrew Tedder, UConn

Nov 26. Justin Bledin, Johns Hopkins

Dec 3. Suki Finn, Southampton

Dec 10. Byong Yi, Toronto

This paper discusses a cluster of interrelated paradoxes, including the semantic and property-theoretic paradoxes (such as the paradox of heterologicality), as well as the set-theoretic paradoxes and the Russell-Myhill paradox. I argue that an independently motivated theory of metaphysical grounding provides philosophically satisfying treatments of these paradoxes. It yields as corollaries a version of the iterative conception of set and an analogous solution to Russell-Myhill. Moreover, it generates a paracomplete solution to the property-theoretic paradoxes. This solution also applies to the semantic paradoxes, which can be subsumed under the property-theoretic ones. The treatment of the property-theoretic paradoxes has structural similarities to Kripke’s approach to the Liar, and it promises to resolve the main outstanding difficulties for this position, such as revenge cases and the problem of adding a conditional with a sufficiently strong logic.

The Logic and Metaphysics Workshop will be meeting on Mondays from 4:15 to 6:15 in room 6494 of the Graduate Center, CUNY (365 5th Avenue). The (provisional) schedule is as follows:

Sep 17. Sander Breckers, Utrecht

Sep 24. Hanoch Ben-Yami, CEU

Oct 1. Otavio Bueno, Miami

Oct 8. GC CLOSED. NO MEETING

Oct 15. Alfredo Freire, Campinas

Oct 22. Yale Weiss, GC

Oct 29. Boris Kment, Princeton

Nov 5. Melissa Fusco, Columbia

Nov 12. Amy Seymour, Fordham

Nov 19. Andrew Tedder, UConn

Nov 26. Justin Bledin, Johns Hopkins

Dec 3. Suki Finn, Southampton

Dec 10. Byong Yi, Toronto

The Free Choice effect—whereby ♢(p or q) seems to entail both ♢p and ♢q—has long been described as a phenomenon affecting the deontic modal “may”. This paper presents an extension of the semantic account of deontic free choice defended in Fusco (2015) to the agentive modal “can”, the “can” which, intuitively, describes an agent’s powers. I begin by sketching a model of inexact ability, which grounds a modal approach to agency (Belnap & Perloff, 1998; Belnap et al., 2001) in a Williamson (1992, 2014)-style margin of error. A classical propositional semantics combined with this framework can reflect the intuitions highlighted by Kenny (1976)’s much-discussed dartboard cases, as well as the counterexamples to simple conditional views recently discussed by Mandelkern et al. (2017). In §3, I substitute for classical disjunction an independently motivated generalization of Boolean join—one which makes the two diagonally, but not generally, equivalent—and show how it extends free choice inferences into a simple object language.

The Logic and Metaphysics Workshop will be meeting on Mondays from 4:15 to 6:15 in room 6494 of the Graduate Center, CUNY (365 5th Avenue). The (provisional) schedule is as follows:

Sep 17. Sander Breckers, Utrecht

Sep 24. Hanoch Ben-Yami, CEU

Oct 1. Otavio Bueno, Miami

Oct 8. GC CLOSED. NO MEETING

Oct 15. Alfredo Freire, Campinas

Oct 22. Yale Weiss, GC

Oct 29. Boris Kment, Princeton

Nov 5. Melissa Fusco, Columbia

Nov 12. Amy Seymour, Fordham

Nov 19. Andrew Tedder, UConn

Nov 26. Justin Bledin, Johns Hopkins

Dec 3. Suki Finn, Southampton

Dec 10. Byong Yi, Toronto

There are competing accounts of the openness of the future, which are structurally similar to competing analyses of ‘can’ and ‘able to do otherwise’. I argue metaphysical openness regarding the future requires the rejection of the commonly assumed tense logic axiom of K_t, (HF): p → HFp. (That is: If p, then it has always been the case that it will be that p). This account of openness both captures the core intuitions in the open future debates and is isomorphic to the libertarian’s account of the ability to do otherwise. Rejecting this axiom does not require a rejection of bivalence. However, a common assumption is that metaphysical future openness requires at least some kind of ontic vagueness. Otherwise, there would be no way to properly account for claims about what the future might hold. I argue this assumption is false: While indeterminism is a necessary feature of the account, indeterminism does not require indeterminacy.

The Logic and Metaphysics Workshop will be meeting on Mondays from 4:15 to 6:15 in room 6494 of the Graduate Center, CUNY (365 5th Avenue). The (provisional) schedule is as follows:

Sep 17. Sander Breckers, Utrecht

Sep 24. Hanoch Ben-Yami, CEU

Oct 1. Otavio Bueno, Miami

Oct 8. GC CLOSED. NO MEETING

Oct 15. Alfredo Freire, Campinas

Oct 22. Yale Weiss, GC

Oct 29. Boris Kment, Princeton

Nov 5. Melissa Fusco, Columbia

Nov 12. Amy Seymour, Fordham

Nov 19. Andrew Tedder, UConn

Nov 26. Justin Bledin, Johns Hopkins

Dec 3. Suki Finn, Southampton

Dec 10. Byong Yi, Toronto

Descartes’ doctrine of the creation of eternal truths seems to claim that there is a class of necessary truths which are, nevertheless, possibly false. In short, these are truths concerning the essences of created things, and so are necessary: yet God, having full voluntary control over the creation of said essences as part of his voluntary control over creation in general, could have failed to create some essences or created them otherwise than he did. This leads to a famous difficulty in interpreting Descartes modal metaphysics. In this talk, I develop an interpretation according to which Descartes countenances two modalities, one constrained by the actual essences God creates (inner modalities), and the other not so constrained (outer modalities). I present some textual evidence to support this reading and develop a model theory capturing the logical behaviour of the modalities.

The Logic and Metaphysics Workshop will be meeting on Mondays from 4:15 to 6:15 in room 6494 of the Graduate Center, CUNY (365 5th Avenue). The (provisional) schedule is as follows:

Sep 17. Sander Breckers, Utrecht

Sep 24. Hanoch Ben-Yami, CEU

Oct 1. Otavio Bueno, Miami

Oct 8. GC CLOSED. NO MEETING

Oct 15. Alfredo Freire, Campinas

Oct 22. Yale Weiss, GC

Oct 29. Boris Kment, Princeton

Nov 5. Melissa Fusco, Columbia

Nov 12. Amy Seymour, Fordham

Nov 19. Andrew Tedder, UConn

Nov 26. Justin Bledin, Johns Hopkins

Dec 3. Suki Finn, Southampton

Dec 10. Byong Yi, Toronto

In this talk, I consider a variant of the ancient Idle Argument involving so-called “unconditionals” with interrogative antecedents. This new Idle Argument provides an ideal setting for probing the logic of these close relatives of “if”-conditionals, which has been comparatively underexplored. In the course of refuting the argument, I argue that contrary to received wisdom, many unconditionals do not entail their main clauses, yet modus ponens is still unrestrictedly valid for this class of expressions. I make these lessons precise in a formal system drawing on recent work in inquisitive semantics. My larger aim is to challenge standard truth preservation accounts of logic and deductive argumentation.

The Logic and Metaphysics Workshop will be meeting on Mondays from 4:15 to 6:15 in room 6494 of the Graduate Center, CUNY (365 5th Avenue). The (provisional) schedule is as follows:

Sep 17. Sander Breckers, Utrecht

Sep 24. Hanoch Ben-Yami, CEU

Oct 1. Otavio Bueno, Miami

Oct 8. GC CLOSED. NO MEETING

Oct 15. Alfredo Freire, Campinas

Oct 22. Yale Weiss, GC

Oct 29. Boris Kment, Princeton

Nov 5. Melissa Fusco, Columbia

Nov 12. Amy Seymour, Fordham

Nov 19. Andrew Tedder, UConn

Nov 26. Justin Bledin, Johns Hopkins

Dec 3. Suki Finn, Southampton

Dec 10. Byong Yi, Toronto

One of the central questions in the metaphysics of pregnancy is this: Is the foetus a part of the mother? In this paper I seek not to answer this question, but rather to raise methodological concerns regarding how to approach answering it. Given the parthood relationship in question, should we be looking to mereology? Or given the biological entities in question, should we be looking to the philosophy of science, or even to biology itself? I will outline how these and various other candidate domains of enquiry attempt to answer whether the foetus is a part of the mother, in order to demonstrate the methodological problems that each approach faces. In moving forward, my positive suggestion will be that we embrace a form of pluralism, and from within each domain adopt a method of reflective equilibrium. The aim of this is to ensure that pregnancy be included in the tribunal of experience to which our theories are held up against, such that our theories will accommodate what we say about pregnancy, whilst also ensuring that what we say about pregnancy will be theoretically informed.

The Logic and Metaphysics Workshop will be meeting on Mondays from 4:15 to 6:15 in room 6494 of the Graduate Center, CUNY (365 5th Avenue). The (provisional) schedule is as follows:

Sep 17. Sander Breckers, Utrecht

Sep 24. Hanoch Ben-Yami, CEU

Oct 1. Otavio Bueno, Miami

Oct 8. GC CLOSED. NO MEETING

Oct 15. Alfredo Freire, Campinas

Oct 22. Yale Weiss, GC

Oct 29. Boris Kment, Princeton

Nov 5. Melissa Fusco, Columbia

Nov 12. Amy Seymour, Fordham

Nov 19. Andrew Tedder, UConn

Nov 26. Justin Bledin, Johns Hopkins

Dec 3. Suki Finn, Southampton

Dec 10. Byong Yi, Toronto

In Semantic Relationism, Kit Fine proposes semantic relationism, the view that semantic relationship among linguistic expressions is not reducible to their intrinsic semantic features, and combines this view with referentialism, the view that intrinsic semantic features of linguistic expressions are exhausted by their referents.  In this talk, I will point out some difficulties with his account and present a way to overcome them by taking a thorough version of semantic relationism.

The Logic and Metaphysics Workshop will be meeting on Mondays from 4:15 to 6:15 in room 6494 of the Graduate Center, CUNY (365 5th Avenue). The (provisional) schedule is as follows:

Sep 17. Sander Breckers, Utrecht

Sep 24. Hanoch Ben-Yami, CEU

Oct 1. Otavio Bueno, Miami

Oct 8. GC CLOSED. NO MEETING

Oct 15. Alfredo Freire, Campinas

Oct 22. Yale Weiss, GC

Oct 29. Boris Kment, Princeton

Nov 5. Melissa Fusco, Columbia

Nov 12. Amy Seymour, Fordham

Nov 19. Andrew Tedder, UConn

Nov 26. Justin Bledin, Johns Hopkins

Dec 3. Suki Finn, Southampton

Dec 10. Byong Yi, Toronto