•  6730
    Naturalness
    with Cian Dorr
    In Karen Bennett & Dean W. Zimmerman (eds.), Oxford Studies in Metaphysics, Volume 8, Oxford University Press. pp. 1. 2013.
    Lewis's notion of a "natural" property has proved divisive: some have taken to the notion with enthusiasm, while others have been sceptical. However, it is far from obvious what the enthusiasts and the sceptics are disagreeing about. This paper attempts to articulate what is at stake in this debate.
  •  4591
    Knowledge and Action
    Journal of Philosophy 105 (10): 571-590. 2008.
    Judging by our folk appraisals, then, knowledge and action are intimately related. The theories of rational action with which we are familiar leave this unexplained. Moreover, discussions of knowledge are frequently silent about this connection. This is a shame, since if there is such a connection it would seem to constitute one of the most fundamental roles for knowledge. Our purpose in this paper is to rectify this lacuna, by exploring ways in which knowing something is related to rationally a…Read more
  •  4568
    Evil and Evidence
    Oxford Studies in Philosophy of Religion 7 1-31. 2016.
    The problem of evil is the most prominent argument against the existence of God. Skeptical theists contend that it is not a good argument. Their reasons for this contention vary widely, involving such notions as CORNEA, epistemic appearances, 'gratuitous' evils, 'levering' evidence, and the representativeness of goods. We aim to dispel some confusions about these notions, in particular by clarifying their roles within a probabilistic epistemology. In addition, we develop new responses to the pro…Read more
  •  2512
    Embedding Epistemic Modals
    with Cian Dorr
    Mind 122 (488): 867-914. 2013.
    Seth Yalcin has pointed out some puzzling facts about the behaviour of epistemic modals in certain embedded contexts. For example, conditionals that begin ‘If it is raining and it might not be raining, … ’ sound unacceptable, unlike conditionals that begin ‘If it is raining and I don’t know it, … ’. These facts pose a prima facie problem for an orthodox treatment of epistemic modals as expressing propositions about the knowledge of some contextually specified individual or group. This paper deve…Read more
  •  1940
    Multiple Universes and Self-Locating Evidence
    Philosophical Review 131 (3): 241-294. 2022.
    Is the fact that our universe contains fine-tuned life evidence that we live in a multiverse? Ian Hacking and Roger White influentially argue that it is not. We approach this question through a systematic framework for self-locating epistemology. As it turns out, leading approaches to self-locating evidence agree that the fact that our own universe contains fine-tuned life indeed confirms the existence of a multiverse. This convergence is no accident: we present two theorems showing that, in thi…Read more
  •  1604
    Knowing against the odds
    Philosophical Studies 170 (2): 277-287. 2014.
    We present and discuss a counterexample to the following plausible principle: if you know that a coin is fair, and for all you know it is going to be flipped, then for all you know it will land tails.
  •  1542
    Higher-order free logic and the Prior-Kaplan paradox
    Canadian Journal of Philosophy 46 (4-5): 493-541. 2016.
    The principle of universal instantiation plays a pivotal role both in the derivation of intensional paradoxes such as Prior’s paradox and Kaplan’s paradox and the debate between necessitism and contingentism. We outline a distinctively free logical approach to the intensional paradoxes and note how the free logical outlook allows one to distinguish two different, though allied themes in higher-order necessitism. We examine the costs of this solution and compare it with the more familiar ramifica…Read more
  •  1383
    Epistemic Modals in Context
    In Gerhard Preyer & Georg Peter (eds.), Contextualism in Philosophy, Oxford University Press. pp. 131-170. 2005.
    A very simple contextualist treatment of a sentence containing an epistemic modal, e.g. a might be F, is that it is true iff for all the contextually salient community knows, a is F. It is widely agreed that the simple theory will not work in some cases, but the counterexamples produced so far seem amenable to a more complicated contextualist theory. We argue, however, that no contextualist theory can capture the evaluations speakers naturally make of sentences containing epistemic modals. If we…Read more
  •  1172
    Minimalism and truth
    Noûs 31 (2): 170-196. 1997.
    This paper canvasses the various dimensions along which theories of truth may disagree about the extent to which truth is minimal.
  •  1158
    David Builes presents a paradox concerning how confident you should be that any given member of an infinite collection of fair coins landed heads, conditional on the information that they were all flipped and only finitely many of them landed heads. We argue that if you should have any conditional credence at all, it should be 1/2.
  •  1089
    Operator arguments revisited
    Philosophical Studies 176 (11): 2933-2959. 2019.
    Certain passages in Kaplan’s ‘Demonstratives’ are often taken to show that non-vacuous sentential operators associated with a certain parameter of sentential truth require a corresponding relativism concerning assertoric contents: namely, their truth values also must vary with that parameter. Thus, for example, the non-vacuity of a temporal sentential operator ‘always’ would require some of its operands to have contents that have different truth values at different times. While making no claims …Read more
  •  1061
    Semantic Plasticity and Speech Reports
    with Cian Dorr
    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
  •  951
    Not So Phenomenal!
    with Maria Lasonen-Aarnio
    The Philosophical Review. forthcoming.
    Our main aims in this paper is to discuss and criticise the core thesis of a position that has become known as phenomenal conservatism. According to this thesis, its seeming to one that p provides enough justification for a belief in p to be prima facie justified (a thesis we label Standard Phenomenal Conservatism). This thesis captures the special kind of epistemic import that seemings are claimed to have. To get clearer on this thesis, we embed it, first, in a probabilistic framework in which …Read more
  •  936
    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
  •  860
    The Necessity of Mathematics
    with Juhani Yli‐Vakkuri
    Noûs 52 (3): 549-577. 2018.
    Some have argued for a division of epistemic labor in which mathematicians supply truths and philosophers supply their necessity. We argue that this is wrong: mathematics is committed to its own necessity. Counterfactuals play a starring role.
  •  837
    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
  •  819
    Conceivability and Possibility (edited book)
    with Tamar Gendler
    Oxford University Press. 2002.
    The capacity to represent things to ourselves as possible plays a crucial role both in everyday thinking and in philosophical reasoning; this volume offers much-needed philosophical illumination of conceivability, possibility, and the relations between them.
  •  811
    God, Schmod and Gratuitous Evil
    Philosophy and Phenomenological Research 53 (4): 861-874. 1993.
    It is common these days for theists to argue that we aren’t justified in believing atheism on the basis of evil. They claim that neither facts about particular horrors nor more holistic considerations pertaining to the magnitude, kinds and distribution of evil can ground atheism since we can't tell whether any evil is gratuitous.1 In this paper we explore a novel strategy for shedding light on these issues: we compare the atheist who claims that there is no morally sufficient reason for certain …Read more
  •  793
    Counterfactual Contamination
    Australasian Journal of Philosophy 100 (2): 262-278. 2022.
    Many defend the thesis that when someone knows p, they couldn’t easily have been wrong about p. But the notion of easy possibility in play is relatively undertheorized. One structural idea in the literature, the principle of Counterfactual Closure (CC), connects easy possibility with counterfactuals: if it easily could have happened that p, and if p were the case, then q would be the case, it follows that it easily could have happened that q. We first argue that while CC is false, there is a tru…Read more
  •  789
    Belief is weak
    Philosophical Studies 173 (5): 1393-1404. 2016.
    It is tempting to posit an intimate relationship between belief and assertion. The speech act of assertion seems like a way of transferring the speaker’s belief to his or her audience. If this is right, then you might think that the evidential warrant required for asserting a proposition is just the same as the warrant for believing it. We call this thesis entitlement equality. We argue here that entitlement equality is false, because our everyday notion of belief is unambiguously a weak one. Be…Read more
  •  701
    The need to address our question arises from two sources, one in Kant and the other in a certain type of response to so-called Reformed epistemology. The first source consists in a tendency to distinguish theoretical beliefs from practical beliefs (commitments to the world's being a certain way versus commitments to certain pictures to live by), and to treat theistic belief as mere practical belief. We trace this tendency in Kant's corpus, and compare and contrast it with Aquinas's view and a mo…Read more
  •  697
    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
  •  651
    Knowledge from multiple experiences
    Philosophical Studies 179 (4): 1341-1372. 2021.
    This paper models knowledge in cases where an agent has multiple experiences over time. Using this model, we introduce a series of observations that undermine the pretheoretic idea that the evidential significance of experience depends on the extent to which that experience matches the world. On the basis of these observations, we model knowledge in terms of what is likely given the agent’s experience. An agent knows p when p is implied by her epistemic possibilities. A world is epistemically po…Read more
  •  626
    Under what conditions are two utterances utterances of the same word? What are words? That these questions have not received much attention is rather surprising: after all, philosophers and linguists frequently appeal to considerations about word and sentence identity in connection with a variety of puzzles and problems that are foundational to the very subject matter of philosophy of language and linguistics.1 Kaplan’s attention to words is thus to be applauded. And there is no doubt that his d…Read more
  •  623
    Safety, Closure, and Extended Methods
    Journal of Philosophy 121 (1): 26-54. 2024.
    Recent research has identified a tension between the Safety principle that knowledge is belief without risk of error, and the Closure principle that knowledge is preserved by competent deduction. Timothy Williamson reconciles Safety and Closure by proposing that when an agent deduces a conclusion from some premises, the agent’s method for believing the conclusion includes their method for believing each premise. We argue that this theory is untenable because it implies problematically easy epist…Read more
  •  611
    As is well known, Aristotelian natural philosophy, and many other systems of natural philosophy since, have relied heavily on teleology and teleological causation. Somehow, the purpose or end of an obj ect can be used to predict and explain what that object does: once you know that the end of an acorn is to become an oak, and a few things about what sorts of circumstances are conducive to the attainment of this end, you can predict a lot about the sprouting of the acorn and the subsequent behavi…Read more
  •  607
    Inheritance: Professor Procrastinate and the logic of obligation1
    with Kyle Blumberg
    Philosophy and Phenomenological Research 106 (1): 84-106. 2021.
    Inheritance is the principle that deontic `ought' is closed under entailment. This paper is about a tension that arises in connection with Inheritance. More specifically, it is about two observations that pull in opposite directions. One of them raises questions about the validity of Inheritance, while the other appears to provide strong support for it. We argue that existing approaches to deontic modals fail to provide us with an adequate resolution of this tension. In response, we develop a po…Read more
  •  591
    Perhaps the concept of knowledge, prior to its being fashioned and molded by certain philosophical traditions, never offered any stable negative verdict in the original fake barn case.
  •  573
    We argue that certain modal questions raise serious problems for a modal metaphysics on which we are permitted to quantify unrestrictedly over all possibilia. In particular, we argue that, on reasonable assumptions, both David Lewis's modal realism and Timothy Williamson's necessitism are saddled with the remarkable conclusion that there is some cardinal number of the form ℵα such that there could not be more than ℵα-many angels in existence. In the last section, we make use of similar ideas to …Read more
  •  540
    Bayesianism, Infinite Decisions, and Binding
    with Frank Arntzenius and Adam Elga
    Mind 113 (450). 2004.
    We pose and resolve several vexing decision theoretic puzzles. Some are variants of existing puzzles, such as 'Trumped' (Arntzenius and McCarthy 1997), 'Rouble trouble' (Arntzenius and Barrett 1999), 'The airtight Dutch book' (McGee 1999), and 'The two envelopes puzzle' (Broome 1995). Others are new. A unified resolution of the puzzles shows that Dutch book arguments have no force in infinite cases. It thereby provides evidence that reasonable utility functions may be unbounded and that reasonab…Read more