Papers
Papers
ABSOLUTION OF A CAUSAL DECISION THEORIST
Noûs, 2023. [preprint] [published version]
I respond to a dilemma for Causal Decision Theory (CDT) under determinism, posed in Adam Elga’s paper “Confessions of a Causal Decision Theorist”. The treatment I present highlights (i) the status of laws as predictors, and (ii) the consequences of decision dependence, which arises natively out of Jeffrey Conditioning and CDT’s characteristic equation.
My argument leverages decision dependence to work around a key assumption of Elga’s proof: to wit, that in the two problems he presents, the CDTer must employ subjunctive-suppositional (rather than evidential) transformations of a shared prior.
DUTCH-BOOKING INDICATIVE CONDITIONALS
Philosophy and Phenomenological Research 107(1), 2023. [preprint] [published version]
Recent literature on Stalnaker’s Thesis, which seeks to vindicate it from Lewis (1976)’s triviality results, has featured linguistic data that is prima facie incompatible with Conditionalization in iterated cases (McGee 1989, 2000; Kaufmann 2015; Khoo & Santorio, 2018). In a recent paper (2021), Goldstein & Santorio make a bold claim: they hold that these departures light the way to a new, non-conditionalizing theory of rational update.
Here, I consider whether this new form of update is subject to a Dutch book. On the official, invariantist version of the theory, I show that the answer is ``yes''. On a competing, contextualist theory of indicative conditionals (Bacon 2015), the answer is ``no", for reasons that have familiar connections to the limits of textbook Bayesianism. After presenting a concrete case, I explore the dialectical ramifications. The upshot is some hard choices for theories that seek to save the linguistic phenomena.
JEFFREY IMAGING REVISITED
Analysis, 2023. [penultimate version (with colour!)] [published version]
In “The Logic of Partial Supposition”, Ben Eva and Stephan Hartmann investigate partial imaging, a credence-revision method which combines the partiality familiar from Jeffrey Conditioning (Jeffrey, 1983) with the formal notion of imaging familiar from Lewis (1981). They argue that because partial imaging is non-monotonic, it “fail[s] to provide a plausible account of the norms of partial subjunctive suppositions.”
In this note, I present a notion of partial imaging that does satisfy monotonicity, and discuss some of the applications and ramifications. The account frames conditioning as a form of imaging, and rejects Gardenfors (1982)'s principle of linearity.
A TWO-DIMENSIONAL LOGIC FOR TWO PARADOXES OF DEONTIC MODALITY (with Arc Kocurek)
Review of Symbolic Logic, 2020. [preprint] [published version]
In this paper, we axiomatize the deontic logic in Fusco (2015), which uses a Stalnaker-inspired account of diagonal acceptance and a two-dimensional account of disjunction to treat Ross's Paradox and the Puzzle of Free Choice Permission. On this account, disjunction-involving validities are a priori rather than necessary. We show how to axiomatize two-dimensional disjunction so that the introduction/elimination rules for boolean disjunciton can be viewed as one-dimensional projections of more general two-dimensional rules. These completeness results help make explicit the restrictions Fusco's account must place on free-choice inferences. They are also of independent interest, as they raise difficult questions about how to “lift” a Kripke frame for a one-dimensional modal logic into two dimensions.
AGENTIAL FREE CHOICE
Journal of Philosophical Logic, 2020. [preprint] [published version]
The free choice effect--whereby <>(p or q) seems to entail both <>p and <>q---has traditionally been characterized affecting the deontic modal “may”. This paper presents an extension of the semantic account of free choice defended in Fusco (2015) to the agentive modal “can”, the “can” which, intuitively, describes an agent’s powers. I begin by sketching a model of inexact agency, which grounds a modal approach to agency (Belnap & Perloff 1998; Belnap, Perloff, and Xu 2001) in a Williamson (1992, 2014)-style margin of error. A classical propositional semantics combined with this framework can reflect the intuitions highlighted by Kenny (1976)’s much-discussed dartboard cases, as well as counterexamples to simple conditional views recently discussed by Mandelkern, Schultheis, and Boylan (2017). In Section 3, I turn to an actual-world-sensitive account of disjunction, and show how it extends free choice inferences into an object language for propositional modal logic.
FREE CHOICE EFFECTS AND EXCLUSIVE DISJUNCTION
Inquiry, 2020. [preprint] [published version]
This paper presents experimental data relevant to understanding the modal free choice effect (Kamp, 1973) when there are more than two disjuncts under the relevant modal operator. The results suggest that speakers’ willingness to draw free choice inferences is correlated with whether the embedded disjuncts are modally separable, in a sense brought into focus by considering cases within which the relevant propositions fail to be pairwise redundant but are redundant as a set.
A TWO-DIMENSIONAL LOGIC FOR DIAGONALIZATION AND THE A PRIORI
Synthese, 2020. [preprint] [published version]
Two-dimensional semantics, which can represent the distinction between necessity and a priority, has wielded considerable influence in the philosophy of language. In this paper, I axiomatize the dagger operator of Stalnaker’s “Assertion” (1978) in two-dimensional modal logic. The language contains modalities of actuality, necessity, and a priority, but is also able to represent diagonalization, a conceptually important operation in a variety of contexts, including models of the relative a priori and a posteriori often appealed to in models of update. Finally, I sketch the prospects for extending this two-dimensional upgrade to other kinds of modal logics for natural language.
SLUICING ON FREE CHOICE
Semantics & Pragmatics, 12: 20 (2019). [preprint] [published version]
I explore the implications of the Tense Phrase deletion operation known as sluicing (Ross 1969) for the semantic and pragmatic literature on the Free Choice effect (Kamp 1973, von Wright, 1969). I argue that the time-honored “I don't know which”-riders on Free Choice sentences, traditionally taken to show that the effect is pragmatic, are sensitive to scope. Careful attention to such riders suggests that these sluices do not show cancellation on Free Choice antecedents in which disjunction scopes narrower than the modal.
NATURALIZING DEONTIC LOGIC
Philosophical Perspectives 32 (2019), pgs 165-187. [preprint] [published version]
It is an appealing idea that deontic modality is a modality of the open future, and that the indeterminacy of the open future is the key, within natural language, to understanding the deontic modal puzzles that form the traditional subject-matter of deontic logic. In this paper, I pull together three well-studied strands of indeterminism—Thomason (1980)’s settledness operator, the modal base of Kratzer (1981, 1991)’s analysis of modals, and Stalnaker (1978)’s notion of diagonal acceptance—to argue for two theses governing a deontic logic for natural language.
The first thesis makes a claim about postsemantic truth, and is couched in terms of Stalnaker’s dagger operator. The second concerns what it is for an act to be permissible, when agents exercise partial control over their obligations as well as their bodily movements.
COUNTERFACTUALS AND THE GIBBARD-HARPER COLLAPSE LEMMA
2019. Destined for a Gibbard Festschrift. [preprint]
Gibbard & Harper (1978) provides a classic statement of Causal Decision Theory (“CDT”), which uses counterfactual conditionals to express the causal relationships that are, according to CDT, of particular relevance to rational decision-making. Classic CDT—in particular, the Gibbard-Harper formulation of it—has been challenged by an influential 2007 paper by Andy Egan (Egan 2007), which presents several counterexamples to the theory. On Egan's telling, causal decision theorists adhere to the motto “do whatever has the best expected outcome, holding fixed your initial views about the likely causal structure of the world” (96). However, Egan argues, there are cases where agents should not hold such initial views fixed as they act. In such cases, agents should use their anticipated future causal views instead, taking into account what they expect to learn by performing the very act in question.
In this paper, I focus on the dialectic from the CDTer's point of view, with an eye to a formal result pointed out by Gibbard & Harper in the third section of their classic paper. There, they show that if an agent's credences are probabilistically coherent, and the semantics for counterfactuals obeys Strong Centering—roughly, the view that each possible world is counterfactually closest to itself—then the probability of (a counterfactual conditional on its antecedent) simplifies to the probability of (its consequent, given its antecedent). This has the eyebrow-raising consequence that “Eganized” causal decision theory, the view on which agents anticipate their future causal views, recommends an act just in case classical evidential decision theory does. The “collapse”, as I call it, complicates the traditional way of glossing the relationship between EDT, CDT, and diachronic coherence norms.
EPISTEMIC TIME BIAS IN NEWCOMB’S PROBLEM
In Arif Ahmed, ed., Newcomb’s Problem (Cambridge University Press), 2018 [preprint]
(Note: this version corrects a typo in the 2019 CUP volume.)
Causal decision theorists like David Lewis hold that, while an agent should choose acts by using her current, rather than anticipated, credences over causal dependency hypotheses, she should also update by conditionalization on her own act as she performs it (Lewis 1981a, 1976). This package leads to an unflattering form of time-bias, which can be highlighted by considering iterated Newcomb problems. After presenting the puzzle, I discuss a CDTer’s best response.
AN INCONVENIENT PROOF: THE GIBBARD-HARPER COLLAPSE LEMMA FOR CAUSAL DECISION THEORY
Proceedings of the 21st Amsterdam Colloquium (2017), pgs. 265-275. [preprint]
I explore a problem for the debate between causal decision theory, formulated in terms of counterfactuals, and its traditional rival, evidential decision theory: agents’ credences in counterfactuals concerning their own acts collapse into evidential probabilities on those acts once diachronic conditionalization on the act is taken into account. Given assumptions that both classical CDTers (Gibbard & Harper, 1978) and their critics (prominently, Egan 2007) accept, it follows that three things cannot be distinct: (i) the probability of a state, given an act; (ii) the probability that if the act were performed, the state would result; and (iii) the probability one would have on that same counterfactual, if one learned that the act was actually performed.
DEONTIC MODALS AND THE SEMANTICS OF CHOICE
Philosophers’ Imprint, 15: 28 (2015), pgs. 1-27. [preprint] [published version]
I propose a unified solution to two puzzles: Ross's puzzle (the apparent failure of Ought p to entail Ought (p or q)) and free choice permission (the apparent fact that May(p or q) entails both May p and May q). I begin with a pair of cases from the decision theory literature illustrating the phenomenon of act dependence, where what an agent ought to do depends on what she does. The notion of permissibility distilled from these cases forms the basis for my analysis of May and Ought. This framework is then combined with a generalization of the classical semantics for disjunction---equivalent to Boolean disjunction on the diagonal, but with a different two-dimensional character---that explains the puzzling facts in terms of semantic consequence.
FACTORING DISJUNCTION OUT OF deontic MODAL PUZZLES
Proceedings of the 12th International Conference in Deontic Logic and Normative Systems (2014), pgs. 95-107. [preprint] [published version]
...Please note an error in Definition 8 in the published version! [errata]
Ross's puzzle (Ross, 1941) and the paradox of Free Choice Permission (Kamp, 1973), puzzles involving disjunction under deontic operators, have received wide discussion in recent work in natural language semantics. First, I contrast two opposed modal views---call them the “box-diamond” theory and EU theory---that form two poles of the contemporary debate. The opposition between them is underwritten by distinct, well-developed conceptions of what it is for an action to be good. I present an axiomatization of obligation and permissibility---of ‘ought’ and ‘may’---that is neutral between the two theories. Adding in the interpretation of ‘or’ as Boolean union, we get the received dialectic in the literature between the two theories on explaining Ross and FCP. Factoring out this assumption, we get a picture of how far apart the two theories are as theories of value, with no questions begged about the semantics of sentential disjunction.
Free Choice Permission and the counterfactuals of pragmatics
Linguistics and Philosophy 37: 4 (2014), pgs. 275-290. [preprint] [published version]
This paper addresses a little puzzle with a surprisingly long pedigree and a surprisingly large wake: the puzzle of Free Choice Permission. I begin by presenting a popular sketch of a pragmatic solution to the puzzle, due to Kratzer and Shimoyama 2002, which has received a good deal of discussion, endorsement and elaboration in recent work (Aloni & van Rooj, 2004; Alonso-Ovalle, 2006; Chierchia, 2006; Fox, 2007; Geurts, 2009; von Fintel, 2012). I then explain why the general form of the Kratzer and Shimoyama explanation is flawed; it relies on false counterfactuals about alternative utterances. Attempts to save the explanation either generate further false counterfactuals, or rely on invalid argument forms employing counterfactuals. Either way, these arguments fail to issue in considerations that are reason-giving for cooperatively rational speakers. This leaves us with two possibilities with regard to the original solution-sketch: either the suggested pragmatic route fails, or it succeeds in a particularly strange way: Free Choice permission is rendered a kind pragmatic illusion on the part of both speakers and hearers. Finally, I investigate the ramifications for the Neo-Gricean programme.
TWO-Dimensional Decision Theory
Economics and Philosophy, special issue on Anna Mahtani’s forthcoming book The Objects of Credence (Cambridge University Press), in press [preprint]
Stalnaker’s ‘Assertion’ (1978 [1999]) offers a classic account of diagonalization as an
approach to the meaning of a declarative sentence in context. Here I explore the
relationship between diagonalization and some puzzles in Mahtani’s book The Objects of
Credence (2024). Diagonalization can influence how we think about both credence and
desirability, so it influences both components of a standard expected utility equation.
In that vein, I touch on two of Mahtani’s case-studies, chance and the finite version of the
Two Envelope Paradox.
REVIEW of MOSS, PROBABILISTIC KNOWLEDGE
in Philosophical Review (2020) [preprint] [published version]