• Knowledge for two
    Science 390 246. 2025.
  • Inexact Knowledge without Improbable Knowing
    Inquiry: An Interdisciplinary Journal of Philosophy 56 (1): 30-53. 2013.
    In a series of recent papers, Timothy Williamson has argued for the surprising conclusion that there are cases in which you know a proposition in spite of its being overwhelmingly improbable given what you know that you know it. His argument relies on certain formal models of our imprecise knowledge of the values of perceptible and measurable magnitudes. This paper suggests an alternative class of models that do not predict this sort of improbable knowing. I show that such models are motivated b…Read more
  • Permutation-invariant social welfare orders are anonymous
    Journal of Mathematical Economics 120. 2025.
    We consider two widely discussed impartiality criteria for social welfare relations: Permutation Invariance, which says that every permutation of the population induces an automorphism of the relation, and Anonymity, which says that every permutation of the population induces a permutation that maps every social welfare distribution to one that is equally good. We show that these criteria are equivalent for social welfare orders (i.e., complete social welfare relations). The new result is that P…Read more
  • Perspectivism
    Noûs 55 (3): 623-648. 2021.
    Consider the sentence “Lois knows that Superman flies, but she doesn’t know that Clark flies”. In this paper we defend a Millian contextualist semantics for propositional attitude ascriptions, according to which ordinary uses of this sentence are true but involve a mid-sentence shift in context. Absent any constraints on the relevant parameters of context sensitivity, such a semantics would be untenable: it would undermine the good standing of systematic theorizing about the propositional attitu…Read more
  • Belief Revision Normalized
    Journal of Philosophical Logic 54 (1): 1-49. 2025.
    We use the normality framework of Goodman and Salow (2018, 2021, 2023b) to investigate of dynamics of rational belief. The guiding idea is that people are entitled to believe that their circumstances aren’t especially abnormal. More precisely, a rational agent’s beliefs rule out all and only those possibilities that are either (i) ruled out by their evidence or (ii) sufficiently less normal than some other possibility not ruled out by their evidence. Working within this framework, we argue that …Read more
  • Williamson on necessitism
    Canadian Journal of Philosophy 46 (4-5): 613-639. 2016.
    I critically discuss some of the main arguments of Modal Logic as Metaphysics, present a different way of thinking about the issues raised by those arguments, and briefly discuss some broader issues about the role of higher-order logic in metaphysics.
  • Higher-order logic as metaphysics
    In Peter Fritz & Nicholas K. Jones (eds.), Higher-Order Metaphysics, Oxford University Press. 2024.
    This chapter offers an opinionated introduction to higher-order formal languages with an eye towards their applications in metaphysics. A simply relationally typed higher-order language is introduced in four stages: starting with first-order logic, adding first-order predicate abstraction, generalizing to higher-order predicate abstraction, and finally adding higher-order quantification. It is argued that both β-conversion and Universal Instantiation are valid on the intended interpretation of t…Read more
  • Epistemology Normalized
    Philosophical Review 132 (1): 89-145. 2023.
    We offer a general framework for theorizing about the structure of knowledge and belief in terms of the comparative normality of situations compatible with one’s evidence. The guiding idea is that, if a possibility is sufficiently less normal than one’s actual situation, then one can know that that possibility does not obtain. This explains how people can have inductive knowledge that goes beyond what is strictly entailed by their evidence. We motivate the framework by showing how it illuminates…Read more
  • Thinking and being sure
    Philosophy and Phenomenological Research 106 (3): 634-654. 2022.
    How is what we believe related to how we act? That depends on what we mean by ‘believe’. On the one hand, there is what we're sure of: what our names are, where we were born, whether we are sitting in front of a screen. Surety, in this sense, is not uncommon — it does not imply Cartesian absolute certainty, from which no possible course of experience could dislodge us. But there are many things that we think that we are not sure of. For example, you might think that it will rain sometime this mo…Read more
  • Diamonds are Forever
    Noûs 54 (3): 632-665. 2019.
    We defend the thesis that every necessarily true proposition is always true. Since not every proposition that is always true is necessarily true, our thesis is at odds with theories of modality and time, such as those of Kit Fine and David Kaplan, which posit a fundamental symmetry between modal and tense operators. According to such theories, just as it is a contingent matter what is true at a given time, it is likewise a temporary matter what is true at a given possible world; so a proposition…Read more
  • Sense, reference and substitution
    Philosophical Studies 177 (4): 947-952. 2020.
    We show that, contrary to conventional wisdom, Frege’s distinction between sense and reference does not reconcile a classical logic of identity with apparent counterexamples to it involving proper names embedded under propositional attitude verbs.
  • Agglomerative Algebras
    Journal of Philosophical Logic 48 (4): 631-648. 2018.
    This paper investigates a generalization of Boolean algebras which I call agglomerative algebras. It also outlines two conceptions of propositions according to which they form an agglomerative algebra but not a Boolean algebra with respect to conjunction and negation.
  • Conditional excluded middle (CEM) is the following principe of counterfactual logic: either, if it were the case that φ, it would be the case that ψ, or, if it were the case that φ, it would be the case that not-ψ. I will first show that CEM entails the identity of indiscernibles, the falsity of physicalism, and the failure of the modal to supervene on the categorical and of the vague to supervene on the precise. I will then argue that we should accept these startling conclusions, since CEM is v…Read more