•  454
    Free will and intensional operators
    Canadian Journal of Philosophy. forthcoming.
    Arguments challenging the existence of free will frequently share a common structure, relying on variants of a principle we call Closure, according to which having no choice about a truth is preserved under entailment. We show that, under plausible assumptions, Closure is valid if and only if the `no choice' operator is intensional. By framing the debate in terms of the intensionality of this operator, this paper illuminates previously underappreciated constraints on defenses of Closure-based ar…Read more
  •  1190
    We present a sound and complete Fitch-style natural deduction system for an S5 modal logic containing an actuality operator, a diagonal necessity operator, and a diagonal possibility operator. The logic is two-dimensional, where we evaluate sentences with respect to both an actual world (first dimension) and a world of evaluation (second dimension). The diagonal necessity operator behaves as a quantifier over every point on the diagonal between actual worlds and worlds of evaluation, while the d…Read more
  •  118
    Freedom, Omniscience and the Contingent A Priori
    Mind 134 (533): 1-32. 2025.
    One of the major challenges in the philosophy of religion is theological fatalism — roughly, the claim that divine omniscience is incompatible with free will. In this article, I present new reasons to be sceptical of what I consider to be the strongest argument for theological fatalism. First, I argue that divine foreknowledge is not necessary for an argument against free will if we take into account divine knowledge of contingent a priori truths. Second, I show that this argument can be general…Read more
  •  1038
    Freedom, Omniscience and the Contingent A Priori
    Mind 134 (533): 1-32. 2024.
    One of the major challenges in the philosophy of religion is theological fatalism—roughly, the claim that divine omniscience is incompatible with free will. In this article, I present new reasons to be skeptical of what I consider to be the strongest argument for theological fatalism. First, I argue that divine foreknowledge is not necessary for an argument against free will if we take into account divine knowledge of contingent a priori truths. Second, I show that this argument can be generaliz…Read more
  •  79
    What is this thing called peace?
    Studia Philosophica Estonica 17 80-95. 2024.
    This article scrutinizes discourse surrounding the Russia-Ukraine war in Western nations, where, despite widespread support for Ukraine, a contingent advocates for peace by rejecting military aid. This “pacifist” stance gains traction through public demonstrations in European countries and political endorsement. However, by opposing military aid while advocating peace, these messages, while ostensibly altruistic, distort genuine efforts for establishing peace in Ukraine. The article argues that …Read more
  •  690
    Rigidity and factivity
    Episteme 1-6. forthcoming.
    David Chalmers argued against the claim that for all p, or even for all entertainable p, it is knowable a priori that p iff actually p. Instead of criticizing Chalmers’s argument, I suggest that it can be generalized, in a sense, and in interesting ways, concerning other principles about contingent a priori truths. In particular, I will argue that the puzzle presented by Chalmers runs parallel to others that do not turn on ‘actually’. Furthermore, stronger arguments can be presented that do not …Read more
  •  1171
    A puzzle about moral responsibility
    with John William Waldrop
    Philosophical Studies 180 (8): 2291-2307. 2023.
    We present a new puzzle about logical truth, necessity, and moral responsibility. We defend one solution to the puzzle. A corollary of our preferred solution is that prominent arguments for the incompatibility of determinism and moral responsibility are invalid.
  •  921
    Naming and Free Will
    Grazer Philosophische Studien 99 (4): 475-484. 2023.
    Rigidity does interesting philosophical work, with important consequences felt throughout metaphysics, epistemology, philosophy of mind, and so on. The authors’ aim in this article is to show that rigidity has yet another role to play, with surprising consequences for the problem of free will and determinism, for the phenomenon of rigidity has the upshot that some metaphysically necessary truths are up to us. The significance of this claim is shown in the context of influential arguments against…Read more
  •  1297
    A puzzle about the fixity of the past
    Analysis 82 (3): 426-434. 2022.
    It is a widely held principle that no one is able to do something that would require the past to have been different from how it actually is. This principle of the fixity of the past has been presented in numerous ways, playing a crucial role in arguments for logical and theological fatalism, and for the incompatibility of causal determinism and the ability to do otherwise. I will argue that, assuming bivalence, this principle is in conflict with standard views about knowledge and the semantics …Read more
  •  1173
    How (not) to construct worlds with responsibility
    Synthese 199 (3-4): 10389-10413. 2021.
    In a recent article, P. Roger Turner and Justin Capes argue that no one is, or ever was, even partly morally responsible for certain world-indexed truths. Here we present our reasons for thinking that their argument is unsound: It depends on the premise that possible worlds are maximally consistent states of affairs, which is, under plausible assumptions concerning states of affairs, demonstrably false. Our argument to show this is based on Bertrand Russell’s original ‘paradox of propositions’. …Read more
  •  1649
    Grim Variations
    with John William Waldrop
    Faith and Philosophy 38 (3): 287-301. 2021.
    Patrick Grim advances arguments meant to show that the doctrine of divine omniscience—the classical doctrine according to which God knows all truths—is false. In particular, we here have in mind to focus on two such arguments: the set theoretic argument and the semantic argument. These arguments due to Grim run parallel to, respectively, familiar paradoxes in set theory and naive truth theory. It is beyond the purview of this article to adjudicate whether or not these are successful arguments ag…Read more
  •  1548
    The Logic of Sequence Frames
    Review of Symbolic Logic 15 (1): 101-132. 2022.
    This paper investigates and develops generalizations of two-dimensional modal logics to any finite dimension. These logics are natural extensions of multidimensional systems known from the literature on logics for a priori knowledge. We prove a completeness theorem for propositional n-dimensional modal logics and show them to be decidable by means of a systematic tableau construction.
  •  1591
    Counterfactuals, counteractuals, and free choice
    Philosophical Studies 178 (2): 445-469. 2020.
    In a recent paper, Pruss proves the validity of the rule beta-2 relative to Lewis’s semantics for counterfactuals, which is a significant step forward in the debate about the consequence argument. Yet, we believe there remain intuitive counter-examples to beta-2 formulated with the actuality operator and rigidified descriptions. We offer a novel and two-dimensional formulation of the Lewisian semantics for counterfactuals and prove the validity of a new transfer rule according to which a new ver…Read more
  •  1204
    ‘Peer Disagreement’ and Evidence of Evidence
    with John Biro
    Logos and Episteme 9 (4): 379-402. 2018.
    What the rational thing to do in the face of disagreement by an epistemic peer is has been much discussed recently. Those who think that a peer’s disagreement is itself evidence against one’s belief, as many do, are committed to a special form of epistemic dependence. If such disagreement is really evidence, it seems reasonable to take it into account and to adjust one’s belief accordingly. But then it seems that the belief one ends up with depends, in part, on what someone else believes, even i…Read more
  •  147
    What is Evidence of Evidence Evidence of?
    with John Biro
    Logos and Episteme 8 (2): 195-206. 2017.
    Richard Feldman’s well-known principle about disagreement and evidence – usually encapsulated in the slogan, ‘evidence of evidence is evidence’, (EEE) – invites the question, what should a rational believer do when faced by such evidence, especially when the disagreement is with an epistemic peer? The question has been the subject of much controversy. However, it has been recently suggested both that the principle is subject to counterexamples and that it is trivial. If either is the case, the q…Read more
  •  1451
    Wierenga on theism and counterpossibles
    Philosophical Studies 176 (3): 693-707. 2019.
    Several theists, including Linda Zagzebski, have claimed that theism is somehow committed to nonvacuism about counterpossibles. Even though Zagzebski herself has rejected vacuism, she has offered an argument in favour of it, which Edward Wierenga has defended as providing strong support for vacuism that is independent of the orthodox semantics for counterfactuals, mainly developed by David Lewis and Robert Stalnaker. In this paper I show that argument to be sound only relative to the orthodox se…Read more
  •  1351
    Actuality and the a priori
    Philosophical Studies 175 (3): 809-830. 2018.
    We consider a natural-language sentence that cannot be formally represented in a first-order language for epistemic two-dimensional semantics. We also prove this claim in the “Appendix” section. It turns out, however, that the most natural ways to repair the expressive inadequacy of the first-order language render moot the original philosophical motivation of formalizing a priori knowability as necessity along the diagonal.
  •  256
    Actuality, Tableaux, and Two-Dimensional Modal Logics
    Erkenntnis 83 (3): 403-443. 2018.
    In this paper we present tableau methods for two-dimensional modal logics. Although models for such logics are well known, proof systems remain rather unexplored as most of their developments have been purely axiomatic. The logics herein considered contain first-order quantifiers with identity, and all the formulas in the language are doubly-indexed in the proof systems, with the upper indices intuitively representing the actual or reference worlds, and the lower indices representing worlds of e…Read more