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27Getting some (non-classical) closure with justification logicAsian Journal of Philosophy 2 (2): 1-25. 2023.Justification logics provide frameworks for studying the fine structure of evidence and justification. Traditionally, these logics do not impose any closure requirements on justification. In this paper, we argue that for some applications they should subject justification to closure under some variety of logical consequence. Specifically, we argue, building on ideas from Beall, that the non-classical logic FDE offers a particularly attractive notion of consequence for this purpose and define a j…Read more
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10Metasequents and TetravaluationsJournal of Philosophical Logic 51 (6): 1453-1476. 2022.In this paper we treat metasequents—objects which stand to sequents as sequents stand to formulas—as first class logical citizens. To this end we provide a metasequent calculus, a sequent calculus which allows us to directly manipulate metasequents. We show that the various metasequent calculi we consider are sound and complete w.r.t. appropriate classes of tetravaluations where validity is understood locally. Finally we use our metasequent calculus to give direct syntactic proofs of various col…Read more
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8Tolerance and the BoundsAnálisis Filosófico 41 (2): 303-316. 2021.The present note investigates the connection between nonreflexive and nontransitive logics from a bounds-theoretic perspective. What will emerge is one way in which, if we focus on the ways in which strict and tolerant acts constrain one another, nonreflexive and nontransitive notions of consequence can be seen as simply reflecting different aspects of the same underlying reality.
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23Proofs and Models in Naive Property Theory: A Response to Hartry Field's ‘Properties, Propositions and Conditionals’Australasian Philosophical Review 4 (2): 162-177. 2020.ABSTRACT In our response Field's ‘Properties, Propositions and Conditionals’, we explore the methodology of Field's program. We begin by contrasting it with a proof-theoretic approach and then commenting on some of the particular choices made in the development of Field's theory. Then, we look at issues of property identity in connection with different notions of equivalence. We close with some comments relating our discussion to Field's response to Restall’s [2010] ‘What Are We to Accept, and W…Read more
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58Metasequents and TetravaluationsJournal of Philosophical Logic 51 (6): 1-24. 2021.In this paper we treat metasequents—objects which stand to sequents as sequents stand to formulas—as first class logical citizens. To this end we provide a metasequent calculus, a sequent calculus which allows us to directly manipulate metasequents. We show that the various metasequent calculi we consider are sound and complete w.r.t. appropriate classes of tetravaluations where validity is understood locally. Finally we use our metasequent calculus to give direct syntactic proofs of various col…Read more
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116Classical counterpossiblesReview of Symbolic Logic 15 (1): 259-275. 2022.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 n…Read more
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32Valuations: Bi, Tri, and TetraStudia Logica 107 (6): 1313-1346. 2019.This paper considers some issues to do with valuational presentations of consequence relations, and the Galois connections between spaces of valuations and spaces of consequence relations. Some of what we present is known, and some even well-known; but much is new. The aim is a systematic overview of a range of results applicable to nonreflexive and nontransitive logics, as well as more familiar logics. We conclude by considering some connectives suggested by this approach.
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36Two traditions in abstract valuational model theorySynthese 198 (S22): 5291-5313. 2019.We investigate two different broad traditions in the abstract valuational model theory for nontransitive and nonreflexive logics. The first of these traditions makes heavy use of the natural Galois connection between sets of valuations and sets of arguments. The other, originating with work by Grzegorz Malinowski on nonreflexive logics, and best systematized in Blasio et al. : 233–262, 2017), lets sets of arguments determine a more restricted set of valuations. After giving a systematic discussi…Read more
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43A dialogical route to logical pluralismSynthese 198 (Suppl 20): 4969-4989. 2019.This paper argues that adopting a particular dialogical account of logical consequence quite directly gives rise to an interesting form of logical pluralism, the form of pluralism in question arising out of the requirement that deductive proofs be explanatory.
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57The World-Time Parallel: Tense and Modality in Logic and Metaphysics, by by A. A. Rini and M. J. Cresswell: Cambridge: Cambridge University Press, 2012, pp. xvii + 260, AUD$125 (review)Australasian Journal of Philosophy 92 (4): 802-805. 2014.
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723Williamson on CounterpossiblesJournal of Philosophical Logic 47 (4): 693-713. 2018.A counterpossible conditional is a counterfactual with an impossible antecedent. Common sense delivers the view that some such conditionals are true, and some are false. In recent publications, Timothy Williamson has defended the view that all are true. In this paper we defend the common sense view against Williamson’s objections.
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35Valuations: Bi, Tri, and TetraStudia Logica 107 (6): 1313-1346. 2019.This paper considers some issues to do with valuational presentations of consequence relations, and the Galois connections between spaces of valuations and spaces of consequence relations. Some of what we present is known, and some even well-known; but much is new. The aim is a systematic overview of a range of results applicable to nonreflexive and nontransitive logics, as well as more familiar logics. We conclude by considering some connectives suggested by this approach.
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49Paradoxes and structural rules from a dialogical perspectivePhilosophical Issues 28 (1): 129-158. 2018.In recent years, substructural approaches to paradoxes have become quite popular. But whatever restrictions on structural rules we may want to enforce, it is highly desirable that such restrictions be accompanied by independent philosophical motivation, not directly related to paradoxes. Indeed, while these recent developments have shed new light on a number of issues pertaining to paradoxes, it seems that we now have even more open questions than before, in particular two very pressing ones: wh…Read more
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37A Simple Sequent Calculus for Angell’s Logic of Analytic ContainmentStudia Logica 105 (5): 971-994. 2017.We give a simple sequent calculus presentation of R.B. Angell’s logic of analytic containment, recently championed by Kit Fine as a plausible logic of partial content.
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91Notational Variance and Its VariantsTopoi 38 (2): 321-331. 2019.What does it take for two logics to be mere notational variants? The present paper proposes a variety of different ways of cashing out notational variance, in particular isolating a constraint on any reasonable account of notational variance which makes plausible that the only kinds of translations which can witness notational variance are what are sometimes called definitional translations.
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41A Sequent Calculus for Urn LogicJournal of Logic, Language and Information 24 (2): 131-147. 2015.Approximately speaking, an urn model for first-order logic is a model where the domain of quantification changes depending on the values of variables which have been bound by quantifiers previously. In this paper we introduce a model-changing semantics for urn-models, and then give a sequent calculus for urn logic by introducing formulas which can be read as saying that “after the individuals a1,..., an have been drawn, A is the case”.
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62Expressive power, mood, and actualitySynthese 190 (9): 1689-1699. 2013.In Wehmeier (J Philos Log 33:607–630, 2004) we are presented with the subjunctive modal language, a way of dealing with the expressive inadequacy of modal logic by marking atomic predicates as being either in the subjunctive or indicative mood. Wehmeier claims that this language is expressively equivalent to the standard actuality language, and that despite this the marked-unmarked dichotomies are not the same in the two languages. In this paper we will attend to Wehmeier’s argument that this is…Read more
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69An Argument Against General Validity?Thought: A Journal of Philosophy 1 (1): 4-9. 2012.This paper argues that a prominent—and oft-thought to be persuasive—argument against general validity as the best account of validity for languages containing the actuality operator is flawed, the flaw arising out of inadequate attention to the formalisation of mood distinctions
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34A Note on the Logic of Eventual Permanence for Linear TimeNotre Dame Journal of Formal Logic 49 (2): 137-142. 2008.In a paper from the 1980s, Byrd claims that the logic of "eventual permanence" for linear time is KD5. In this note we take up Byrd's novel argument for this and, treating the problem as one concerning translational embeddings, show that rather than KD5 the correct logic of "eventual permanence" is KD45
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49A simplified embedding of E into monomodal KLogic Journal of the IGPL 17 (4): 421-428. 2009.In this paper we will provide a modal-to-modal translational embedding of E into K, simplifying a similar result which is obtainable using a novel translation due to S.K. Thomason.
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25In the Mood for S4: The Expressive Power of the Subjunctive Modal Language in Weak Background LogicsStudia Logica 103 (2): 239-263. 2015.Our concern here is with the extent to which the expressive equivalence of Wehmeier’s Subjunctive Modal Language and the Actuality Modal Language is sensitive to the choice of background modal logic. In particular we will show that, when we are enriching quantified modal logics weaker than S5, AML is strictly expressively stronger than SML, this result following from general considerations regarding the relationship between operators and predicate markers. This would seem to complicate arguments…Read more
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78An Argument for the Ontological Innocence of MereologyErkenntnis 81 (4): 683-704. 2016.In Parts of Classes David Lewis argued that mereology is ‘ontologically innocent’, mereological notions not incurring additional ontological commitments. Unfortunately, though, Lewis’s argument for this is not fully spelled out. Here we use some formal results concerning translations between formal languages to argue for the ontological innocence of mereology directly.
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725Contractions of noncontractive consequence relationsReview of Symbolic Logic 8 (3): 506-528. 2015.Some theorists have developed formal approaches to truth that depend on counterexamples to the structural rules of contraction. Here, we study such approaches, with an eye to helping them respond to a certain kind of objection. We define a contractive relative of each noncontractive relation, for use in responding to the objection in question, and we explore one example: the contractive relative of multiplicative-additive affine logic with transparent truth, or MAALT.
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51Partial Confirmation of a Conjecture on the Boxdot Translation in Modal LogicAustralasian Journal of Logic 7 56-61. 2009.The purpose of the present note is to advertise an interesting conjecture concerning a well-known translation in modal logic, by confirming a (highly restricted) special case of the conjecture.
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23An observation concerning porte's rule in modal logicBulletin of the Section of Logic 44 (1/2): 25-31. 2015.It is well known that no consistent normal modal logic contains (as theorems) both ♦A and ♦¬A (for any formula A). Here we observe that this claim can be strengthened to the following: for any formula A, either no consistent normal modal logic contains ♦A, or else no consistent normal modal logic contains ♦¬A.
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30Denumerably Many Post-Complete Normal Modal Logics with Propositional ConstantsNotre Dame Journal of Formal Logic 53 (4): 549-556. 2012.We show that there are denumerably many Post-complete normal modal logics in the language which includes an additional propositional constant. This contrasts with the case when there is no such constant present, for which it is well known that there are only two such logics.
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91Structural Reflexivity and the Paradoxes of Self-ReferenceErgo: An Open Access Journal of Philosophy 3. 2016.
Davis, California, United States of America
Areas of Specialization
Logic and Philosophy of Logic |
Areas of Interest
Epistemology |
Metaphysics |
Philosophy of Language |