
1851Explaining the Abstract/Concrete Paradoxes in Moral Psychology: The NBAR HypothesisReview of Philosophy and Psychology 3 (3): 351368. 2012.For some reason, participants hold agents more responsible for their actions when a situation is described concretely than when the situation is described abstractly. We present examples of this phenomenon, and survey some attempts to explain it. We divide these attempts into two classes: affective theories and cognitive theories. After criticizing both types of theories we advance our novel hypothesis: that people believe that whenever a norm is violated, someone is responsible for it. This bel…Read more

1209Paradoxes and Failures of CutAustralasian Journal of Philosophy 91 (1). 2013.This paper presents and motivates a new philosophical and logical approach to truth and semantic paradox. It begins from an inferentialist, and particularly bilateralist, theory of meaningone which takes meaning to be constituted by assertibility and deniability conditionsand shows how the usual multipleconclusion sequent calculus for classical logic can be given an inferentialist motivation, leaving classical model theory as of only derivative importance. The paper then uses this theory …Read more

1012Conservatively extending classical logic with transparent truthReview of Symbolic Logic 5 (2): 354378. 2012.This paper shows how to conservatively extend classical logic with a transparent truth predicate, in the face of the paradoxes that arise as a consequence. All classical inferences are preserved, and indeed extended to the full (truth—involving) vocabulary. However, not all classical metainferences are preserved; in particular, the resulting logical system is nontransitive. Some limits on this nontransitivity are adumbrated, and two proof systems are presented and shown to be sound and complete.…Read more

996Contradictions at the bordersIn Rick Nouwen, Robert van Rooij, Uli Sauerland & HansChristian Schmitz (eds.), Vagueness in Communication, Springer. pp. 169188. 2011.The purpose of this essay is to shed some light on a certain type of sentence, which I call a borderline contradiction. A borderline contradiction is a sentence of the form F a ∧ ¬F a, for some vague predicate F and some borderline case a of F , or a sentence equivalent to such a sentence. For example, if Jackie is a borderline case of ‘rich’, then ‘Jackie is rich and Jackie isn’t rich’ is a borderline contradiction. Many theories of vague language have entailments about borderline contradiction…Read more

836Williamson on CounterpossiblesJournal of Philosophical Logic 47 (4): 693713. 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.

812Anything GoesTopoi 34 (1): 2536. 2015.This paper consider Prior's connective Tonk from a particular bilateralist perspective. I show that there is a natural perspective from which we can see Tonk and its ilk as perfectly welldefined pieces of vocabulary; there is no need for restrictions to bar things like Tonk.

791Contractions of noncontractive consequence relationsReview of Symbolic Logic 8 (3): 506528. 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 multiplicativeadditive affine logic with transparent truth, or MAALT.

625Embedding DenialIn Colin R. Caret & Ole T. Hjortland (eds.), Foundations of Logical Consequence, Oxford University Press. pp. 289309. 2015.Suppose Alice asserts p, and the Caterpillar wants to disagree. If the Caterpillar accepts classical logic, he has an easy way to indicate this disagreement: he can simply assert ¬p. Sometimes, though, things are not so easy. For example, suppose the Cheshire Cat is a paracompletist who thinks that p ∨ ¬p fails (in familiar (if possibly misleading) language, the Cheshire Cat thinks p is a gap). Then he surely disagrees with Alice's assertion of p, but should himself be unwilling to assert ¬p. So…Read more

414Tolerant, Classical, StrictJournal of Philosophical Logic 41 (2): 347385. 2012.In this paper we investigate a semantics for firstorder logic originally proposed by R. van Rooij to account for the idea that vague predicates are tolerant, that is, for the principle that if x is P, then y should be P whenever y is similar enough to x. The semantics, which makes use of indifference relations to model similarity, rests on the interaction of three notions of truth: the classical notion, and two dual notions simultaneously defined in terms of it, which we call tolerant truth and…Read more

358Structures and circumstances: two ways to finegrain propositionsSynthese 189 (1). 2012.This paper discusses two distinct strategies that have been adopted to provide finegrained propositions; that is, propositions individuated more finely than sets of possible worlds. One strategy takes propositions to have internal structure, while the other looks beyond possible worlds, and takes propositions to be sets of circumstances, where possible worlds do not exhaust the circumstances. The usual arguments for these positions turn on finenessofgrain issues: just how finely should propos…Read more

353Expectations and morality: A dilemmaBehavioral and Brain Sciences 33 (4): 346346. 2010.We propose Knobe's explanation of his cases encounters a dilemma: Either his explanation works and, counterintuitively, morality is not at the heart of these effects; or morality is at the heart of the effects and Knobe's explanation does not succeed. This dilemma is then used to temper the use of the Knobe paradigm for discovering moral norms

298Negation, Denial, and RejectionPhilosophy Compass 6 (9): 622629. 2011.At least since [Frege, 1960] and [Geach, 1965], there has been some consensus about the relation between negation, the speech act of denial, and the attitude of rejection: a denial, the consensus has had it, is the assertion of a negation, and a rejection is a belief in a negation. Recently, though, there have been notable deviations from this orthodox view. Rejectivists have maintained that negation is to be explained in terms of denial or rejection, rather than vice versa. Some other theorists…Read more

290On the Ternary Relation and ConditionalityJournal of Philosophical Logic 41 (3). 2012.One of the most dominant approaches to semantics for relevant (and many paraconsistent) logics is the RoutleyMeyer semantics involving a ternary relation on points. To some (many?), this ternary relation has seemed like a technical trick devoid of an intuitively appealing philosophical story that connects it up with conditionality in general. In this paper, we respond to this worry by providing three different philosophical accounts of the ternary relation that correspond to three conceptions o…Read more

264How Mathematics Can Make a DifferencePhilosophers' Imprint 17. 2017.Standard approaches to counterfactuals in the philosophy of explanation are geared toward causal explanation. We show how to extend the counterfactual theory of explanation to noncausal cases, involving extramathematical explanation: the explanation of physical facts by mathematical facts. Using a structural equation framework, we model impossible perturbations to mathematics and the resulting differences made to physical explananda in two important cases of extramathematical explanation. We …Read more

202Reaching Transparent TruthMind 122 (488): 841866. 2013.This paper presents and defends a way to add a transparent truth predicate to classical logic, such that and A are everywhere intersubstitutable, where all Tbiconditionals hold, and where truth can be made compositional. A key feature of our framework, called STTT (for StrictTolerant Transparent Truth), is that it supports a nontransitive relation of consequence. At the same time, it can be seen that the only failures of transitivity STTT allows for arise in paradoxical cases

192Responsibility and the brain sciencesEthical Theory and Moral Practice 12 (5): 511524. 2008.Some theorists think that the more we get to know about the neural underpinnings of our behaviors, the less likely we will be to hold people responsible for their actions. This intuition has driven some to suspect that as neuroscience gains insight into the neurological causes of our actions, people will cease to view others as morally responsible for their actions, thus creating a troubling quandary for our legal system. This paper provides empirical evidence against such intuitions. Particular…Read more

188Nonclassical theories of truthIn Jc Beall & David Ripley (eds.), Oxford Handbook of Truth, . 2018.This chapter attempts to give a brief overview of nonclassical (logic) theories of truth. Due to space limitations, we follow a victorythroughsacrifice policy: sacrifice details in exchange for clarity of bigpicture ideas. This policy results in our giving alltoobrief treatment to certain topics that have dominated discussion in the nonclassicallogic area of truth studies. (This is particularly so of the ‘suitable conditoinal’ issue: §4.3.) Still, we present enough representative ideas t…Read more

177Sorting out the soritesIn Francesco Berto, Edwin Mares, Koji Tanaka & Francesco Paoli (eds.), Paraconsistency: Logic and Applications, Springer. pp. 329348. 2013.Supervaluational theories of vagueness have achieved considerable popularity in the past decades, as seen in eg [5], [12]. This popularity is only natural; supervaluations let us retain much of the power and simplicity of classical logic, while avoiding the commitment to strict bivalence that strikes many as implausible. Like many nonclassical logics, the supervaluationist system SP has a natural dual, the subvaluationist system SB, explored in eg [6], [28].1 As is usual for such dual systems, t…Read more

176Identity, Leibniz’s Law and NonTransitive ReasoningMetaphysica 14 (2): 253264. 2013.Arguments based on Leibniz's Law seem to show that there is no room for either indefinite or contingent identity. The arguments seem to prove too much, but their conclusion is hard to resist if we want to keep Leibniz's Law. We present a novel approach to this issue, based on an appropriate modification of the notion of logical consequence.

168Review of Vagueness and degrees of truth, by Nicholas J. Smith (review)Analysis 70 (1): 188190. 2010.(No abstract is available for this citation)

149A Counterfactual Approach to Explanation in MathematicsPhilosophia Mathematica 28 (1): 134. 2020.ABSTRACT Our goal in this paper is to extend counterfactual accounts of scientific explanation to mathematics. Our focus, in particular, is on intramathematical explanations: explanations of one mathematical fact in terms of another. We offer a basic counterfactual theory of intramathematical explanations, before modelling the explanatory structure of a test case using counterfactual machinery. We finish by considering the application of counterpossibles to mathematical explanation, and explor…Read more

129Classical counterpossiblesReview of Symbolic Logic 15 (1): 259275. 2022.We present four classical theories of counterpossibles that combine modalities and counterfactuals. Two theories are antivacuist and forbid vacuously true counterfactuals, two are quasivacuist 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

123Vagueness, Truth and Permissive ConsequenceIn T. Achourioti, H. Galinon, J. Martínez Fernández & K. Fujimoto (eds.), Unifying the Philosophy of Truth, Imprint: Springer. pp. 409430. 2015.We say that a sentence A is a permissive consequence of a set X of premises whenever, if all the premises of X hold up to some standard, then A holds to some weaker standard. In this paper, we focus on a threevalued version of this notion, which we call stricttotolerant consequence, and discuss its fruitfulness toward a unified treatment of the paradoxes of vagueness and selfreferential truth. For vagueness, stconsequence supports the principle of tolerance; for truth, it supports the requi…Read more

113Tolerance and Mixed Consequence in the S'valuationist SettingStudia Logica 100 (4): 855877. 2012.In a previous paper (see ‘Tolerant, Classical, Strict’, henceforth TCS) we investigated a semantic framework to deal with the idea that vague predicates are tolerant, namely that small changes do not affect the applicability of a vague predicate even if large changes do. Our approach there rests on two main ideas. First, given a classical extension of a predicate, we can define a strict and a tolerant extension depending on an indifference relation associated to that predicate. Second, we can us…Read more

112Vagueness and Order Effects in Color CategorizationJournal of Logic, Language and Information 22 (4): 391420. 2013.This paper proposes an experimental investigation of the use of vague predicates in dynamic sorites. We present the results of two studies in which subjects had to categorize colored squares at the borderline between two color categories (Green vs. Blue, Yellow vs. Orange). Our main aim was to probe for hysteresis in the ordered transitions between the respective colors, namely for the longer persistence of the initial category. Our main finding is a reverse phenomenon of enhanced contrast (i.e.…Read more

111Paraconsistent LogicJournal of Philosophical Logic 44 (6): 771780. 2015.In some logics, anything whatsoever follows from a contradiction; call these logics explosive. Paraconsistent logics are logics that are not explosive. Paraconsistent logics have a long and fruitful history, and no doubt a long and fruitful future. To give some sense of the situation, I’ll spend Section 1 exploring exactly what it takes for a logic to be paraconsistent. It will emerge that there is considerable open texture to the idea. In Section 2, I’ll give some examples of techniques for dev…Read more

104Comparing Substructural Theories of TruthErgo: An Open Access Journal of Philosophy 2. 2015.Substructural theories of truth are theories based on logics that do not include the full complement of usual structural rules. Existing substructural approaches fall into two main families: noncontractive approaches and nontransitive approaches. This paper provides a sketch of these families, and argues for two claims: first, that substructural theories are betterpositioned than other theories to grapple with the truththeoretic paradoxes, and second—more tentatively—that nontransitive approac…Read more

102Inconstancy and inconsistencyIn Petr Cintula, Christian Fermuller, Lluis Godo & Petr Hajek (eds.), Reasoning Under Vagueness, College Publications. pp. 4158. 2011.In everyday language, we can call someone ‘consistent’ to say that they’re reliable, that they don’t change over time. Someone who’s consistently on time is always on time. Similarly, we can call someone ‘inconsistent’ to say the opposite: that they’re changeable, mercurial. A student who receives inconsistent grades on her tests throughout a semester has performed better on some than on others. With our philosophy hats on, though, we mean something quite different by ‘consistent’ and ‘inconsist…Read more

95Revising Up: Strengthening Classical Logic in the Face of ParadoxPhilosophers' Imprint 13. 2013.This paper provides a defense of the full strength of classical logic, in a certain form, against those who would appeal to semantic paradox or vagueness in an argument for a weaker logic. I will not argue that these paradoxes are based on mistaken principles; the approach I recommend will extend a familiar formulation of classical logic by including a fully transparent truth predicate and fully tolerant vague predicates. It has been claimed that these principles are not compatible with classica…Read more
Areas of Specialization
Philosophy of Language 
Logic and Philosophy of Logic 
Areas of Interest
Metaphysics 
Philosophy of Mind 
Philosophy of Cognitive Science 