• Arithmetic is Determinate
    Journal of Philosophical Logic 51 (1): 127-150. 2021.
    Orthodoxy holds that there is a determinate fact of the matter about every arithmetical claim. Little argument has been supplied in favour of orthodoxy, and work of Field, Warren and Waxman, and others suggests that the presumption in its favour is unjustified. This paper supports orthodoxy by establishing the determinacy of arithmetic in a well-motivated modal plural logic. Recasting this result in higher-order logic reveals that even the nominalist who thinks that there are only finitely many …Read more
  • Uttering Moorean Sentences and the pragmatics of belief reports
    Philosophical Studies 178 (6): 1879-1895. 2020.
    Moore supposedly discovered that there are sentences of a certain form that, though they can be true, no rational human being can sincerely and truly utter any of them. MC and MO are particular instances:MC: “It is raining and I believe that it is not raining”MO: “It is raining and I don’t believe that it is raining”In this paper, I show that there are sentences of the same form as MC and MO that can be sincerely and truly uttered by rational agents. We call sentences of the same form as MC and …Read more
  • Frege - Begriffschrift, eine der Arithmetischen nachgebildete Formelsprache des reinen Denkens (review)
    Paul Tannery
    Revue Philosophique de la France Et de l'Etranger 8 108-109. 1879.
  • I consider a puzzling case presented by Jose Benardete, and by appeal to this case develop a paradox involving counterfactual conditionals. I then show that this paradox may be leveraged to argue for certain non-obvious claims concerning the logic of counterfactuals.
  • We present a puzzle about knowledge, probability and conditionals. We show that in certain cases some basic and plausible principles governing our reasoning come into conflict. In particular, we show that there is a simple argument that a person may be in a position to know a conditional the consequent of which has a low probability conditional on its antecedent, contra Adams’ Thesis. We suggest that the puzzle motivates a very strong restriction on the inference of a conditional from a disjunct…Read more
  • Suppose you’d like to believe that p, whether or not it’s true. What can you do to help? A natural initial thought is that you could engage in Intentionally Biased Inquiry : you could look into whether p, but do so in a way that you expect to predominantly yield evidence in favour of p. This paper hopes to do two things. The first is to argue that this initial thought is mistaken: intentionally biased inquiry is impossible. The second is to show that reflections on intentionally biased inquiry s…Read more
  • Quantum Mechanics as Classical Physics
    Philosophy of Science 82 (2): 266-291. 2015.
    Here I explore a novel no-collapse interpretation of quantum mechanics that combines aspects of two familiar and well-developed alternatives, Bohmian mechanics and the many-worlds interpretation. Despite reproducing the empirical predictions of quantum mechanics, the theory looks surprisingly classical. All there is at the fundamental level are particles interacting via Newtonian forces. There is no wave function. However, there are many worlds.
  • Groupthink
    Philosophical Studies 172 (5): 1287-1309. 2015.
    How should a group with different opinions (but the same values) make decisions? In a Bayesian setting, the natural question is how to aggregate credences: how to use a single credence function to naturally represent a collection of different credence functions. An extension of the standard Dutch-book arguments that apply to individual decision-makers recommends that group credences should be updated by conditionalization. This imposes a constraint on what aggregation rules can be like. Taking c…Read more
  • General Dynamic Triviality Theorems
    Philosophical Review 125 (3): 307-339. 2016.
    Famous results by David Lewis show that plausible-sounding constraints on the probabilities of conditionals or evaluative claims lead to unacceptable results, by standard probabilistic reasoning. Existing presentations of these results rely on stronger assumptions than they really need. When we strip these arguments down to a minimal core, we can see both how certain replies miss the mark, and also how to devise parallel arguments for other domains, including epistemic “might,” probability claim…Read more
  • Possible Patterns
    Oxford Studies in Metaphysics 11. 2018.
    “There are no gaps in logical space,” David Lewis writes, giving voice to sentiment shared by many philosophers. But different natural ways of trying to make this sentiment precise turn out to conflict with one another. One is a *pattern* idea: “Any pattern of instantiation is metaphysically possible.” Another is a *cut and paste* idea: “For any objects in any worlds, there exists a world that contains any number of duplicates of all of those objects.” We use resources from model theory to show …Read more
  • Semantic Plasticity and Speech Reports
    Philosophical Review 123 (3): 281-338. 2014.
    Most meanings we express belong to large families of variant meanings, among which it would be implausible to suppose that some are much more apt for being expressed than others. This abundance of candidate meanings creates pressure to think that the proposition attributing any particular meaning to an expression is modally plastic: its truth depends very sensitively on the exact microphysical state of the world. However, such plasticity seems to threaten ordinary counterfactuals whose consequen…Read more
  • To Be F Is To Be G
    Philosophical Perspectives 30 (1): 39-134. 2016.
    This paper is an investigation of the general logic of "identifications", claims such as 'To be a vixen is to be a female fox', 'To be human is to be a rational animal', and 'To be just is to help one's friends and harm one's enemies', many of which are of great importance to philosophers. I advocate understanding such claims as expressing higher-order identity, and discuss a variety of different general laws which they might be thought to obey. [New version: Nov. 4th, 2016]
  • 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