Conditional heresies
The principles of Conditional Excluded Middle (CEM) and Simplification of Disjunctive Antecedents (SDA) have received substantial attention in isolation. Both principles are plausible generalizations about natural language conditionals. But the two principles have not been discussed much in combination. This paper explores the significance of having both principles constrain the logic of the conditional. Our negative finding is that, together with elementary logical assumptions, CEM and SDA yield a variety of implausible consequences. Despite these incompatibility results, we open up a narrow space to satisfy both. We show that, by simultaneously appealing to the alternative-introducing analysis of disjunction (Alonso Ovalle 2006) and to the theory of homogeneity presuppositions (von Fintel 1997), we can satisfy both. Furthermore, the theory that validates both principles resembles a recent proposal that Santorio (2017) defends on independent grounds. The cost of this approach is that it must give up the transitivity of entailment: we suggest that this is a feature, not a bug, and connect it with with recent developments of intransitive notions of entailment (Ripley 2013, 2015).

coauthored with Fabrizio Cariani

Philosophy and Phenomenological Research 2018 (accepted pending minor changes) | link

Generalized update semantics
This paper develops a dynamic semantics for epistemic modals that is a generalization of both the update semantics for modals from Veltman 1996 and the more traditional semantics for modals from Kripke. This semantics gives us the tools to understand precisely the consequences of the inconsistency of epistemic contradictions (sentences of the form 'p and might not p') for the meaning of epistemic modals. In particular, within this framework the inconsistency of epistemic contradictions implies both that positive introspection is valid, and that necessity modals are strong. In addition, the semantics offers a general procedure for taking any classical semantics for modals and converting it into a dynamic semantics for modals that predicts the inconsistency of epistemic contradictions. The upshot is that there is a well behaved and modular way to predict that epistemic contradictions are inconsistent, which can be added to any preexisting theory of modals.

Mind 2018 (accepted pending minor changes) | link

A stronger doctrine of double effect
Many believe that intended harms are more difficult to justify than harms which result as a foreseen side effect of one's conduct. We describe cases of harming in which the harm is not intended, yet the harmful act nevertheless runs afoul of the intuitive moral constraint which governs intended harms. We note that these cases provide new and improved counterexamples to the so-called Simple View, according to which intentionally A-ing requires intending to A. We then give a new theory of the moral relevance of intention. This theory yields the traditional constraint on intending harm as a special case, along with several stronger demands.

coauthored with Ben Bronner

Australasian Journal of Philosophy 2017 | link

Informative dynamic semantics
In dynamic semantics, the meaning of a sentence is modeled as a rule for how a body of information grows when the sentence is accepted. Recent work in dynamic semantics has analyzed sentences involving modals and conditionals as tests. Tests are a special type of dynamic meaning. When an agent learns a test, her information is guaranteed to either stay the same, or become absurd. The aim of this dissertation is to separate dynamic semantics from the notion of a test. The dissertation offers new analyses of modals, conditionals, and disjunction on which they are not tests. Nonetheless, these analyses are still genuinely dynamic. The meaning of sentences involving these expressions cannot be represented as a rule instructing the agent to update her information with the claim that she inhabits one of a fixed set of possibilities - that a certain proposition is true. Rather, the rule for how she is to update her information must make essential reference to her current information, providing different instructions depending on what that information is like.

My dissertation

Rutgers University 2017 | link

Triviality results for probabilistic modals
In recent years, a number of theorists have claimed that beliefs about probability are transparent. To believe probably p is simply to have a high credence that p. These same theorists have also defended non-factualist theories of probabilistic modals. On this view, probabilistic sentences do not express propositions; rather, they are semantically associated with sets of probability functions. But what exactly is the connection between transparency and nonfactualism? In this paper, I prove a triviality result for probabilistic modals. If these modals satisfy transparency, then they cannot express propositions: they must be nonfactual. However, there is a problem for nonfactualism. I formulate another version of transparency as a principle governing the logic of the probabilistic modal n% likely. I then prove some impossibility results, showing that this second transparency thesis is incompatible with n% likely obeying the probability calculus.

Philosophy and Phenomenological Research 2017 | link

Believing epistemic contradictions
What is it to believe something might be the case? We raise a challenge for standard answers to this question. We begin by developing a new puzzle involving belief, epistemic modals, and certainty. After showing that standard treatments of beliefs involving epistemic modals fail to resolve our puzzle, we propose our own solution, which integrates a Bayesian approach to belief with a dynamic semantics for epistemic modals. We go on to investigate a surprising consequence of our solution to the puzzle: virtually all of our beliefs about what might be the case provide counterexamples to the view that rational belief is closed under logical implication.

coauthored with Bob Beddor

The Review of Symbolic Logic 2017 | link

A preface paradox for intention

In this paper I argue that there is a preface paradox for intention. The preface paradox for intention shows that intentions do not obey an agglomeration norm. But what norms do intentions obey? I argue that intentions come in degrees. These `partial' intentions are governed by the norms of the probability calculus.

First, I give a dispositional theory of partial intention. Dispositions come in degrees. Intentions are dispositions. So the degree to which you intend to A is simply the degree to which you possess the dispositions characteristic of intending to A. Second, I use this theory to defend probabilism about intentions. Intentions involve some degreed dispositions. Degrees can be ordered from 0 to 1. So an agent's degree of dispositions involved in Aing can satisfy the probability calculus. I show that if they do not, the agent is irrational.

But this argument assumes my particular theory of partial intention. One might look for a more general approach. In the rest of the paper, I offer a decision theoretic argument for probabilism about intentions. I show that if an agent's partial intentions do not satisfy the probability calculus, then she violates a variety of plausible decision theoretic norms. These arguments extend `epistemic utility' theory from beliefs to intentions.

Philosophers' Imprint 2016 | link