• “Two Notions of Metaphysical Modality” 

Synthese (2018): 1-22.

The paper explores the project of an ambitious modal epistemology that attempts to combine the a priori methods of Chalmers’ 2D semantics with Kripke’s modal metaphysics. I argue that such a project is not viable. The ambitious modal epistemology involves an inconsistent triad composed of (1) Modal Monism, (2) Two-Dimensionalism, and what I call (3) “Metaphysical Kripkeanism”. I present the three theses and show how only two of those can be true at a time. There is a fundamental incompatibility between Chalmers’ Modal Rationalism and Kripke’s modal metaphysics. Specifically, Chalmers’ conceivability entails possibilities that a Kripkean rejects as genuinely metaphysical. However, three positive stances in modal epistemology emerge from the combinations that the triad allows. One of those offers a promising way forward for 2D modal epistemologies. But it comes with a cost, as it requires abandoning modal monism and reshaping the scope of what a priori conceivability can give us access to.

Penultimate draft here:


  • “Putting Modal Metaphysics First”

Synthese (2018): 1-20.

I propose that we approach the epistemology of modality by putting modal metaphysics first and, specifically, by investigating the metaphysics of essence. Following a prominent Neo-Aristotelian view, I hold that metaphysical necessity depends on the nature of things, namely their essences. I further clarify that essences are core properties having distinctive superexplanatory powers. In the case of natural kinds, which is my focus in the paper, superexplanatoriness is due to the fact that the essence of a kind is what causes all the many properties and behaviors that are typically shared by all the instances of the kind. Accordingly, we know what is necessarily true of kinds by knowing what is essential to them in the sense of actually playing such causal-explanatory roles. Modal reasoning aimed at discovering metaphysical necessity thus proceeds via essentialist deduction: we move from essentialist truths to reach necessary truths.

Penultimate draft here:


  • “Essential Properties are Super-Explanatory. Taming Metaphysical Modality” 

(with M. Godman and D. Papineau)

This paper aims to build a bridge between two areas of philosophical research, the structure of kinds and metaphysical modality. Our central thesis is that kinds typically involve super-explanatory properties, and that these properties lie behind all substantial cases of metaphysical necessity.

Penultimate draft here:


  • “Essentialist Constraints on Counterfactual Knowledge”

(In preparation for Modal Thinking, A. Vaidya & D. Prelevic, eds., OUP)

In this paper I compare my approach to modal knowledge—a form of Essentialist Deduction, which grounds knowledge of metaphysical modality in knowledge of essence—against Williamson’s Counterfactual Theory of modal knowledge. I discuss a number of problems that have been raised against Williamson’s theory, and argue that those all ultimately trace back to a common source. Namely, the failure to elucidate the proper normative constraints on modal reasoning. This is the central problem of “Modal Epistemic Friction” for modal epistemology (Vaidya and Wallner forthcoming). On the other hand, the “Essentialist Superexplanatory” account I defend successfully addresses the problem of Modal Epistemic Friction. For it clarifies that (a) the proper constraints on metaphysical modal reasoning are essentialist constraints; and that (b) essences have distinctive causal and explanatory powers. As such, the Essentialist Superexplanatory account is an overall better choice than Counterfactual Theory in the epistemology of modality.


  • “Modal Pluralism and Purely A Priori Necessities”

I lay out a pluralistic picture of modal space which distinguishes different modal subfields and kinds of necessity, based on their source. In particular, the model integrates a variety of those I call “purely a priori necessities” (i.e., logical necessity, mathematical necessity, normative necessity, etc.), alongside those I call “distinctively metaphysical” or “Kripkean” necessities. The latter are de re, a posteriori necessities having their source in the nature or essence of things, where essences are causally-explanatorily powerful properties or mechanisms. Furthermore, all the different modal sub-fields can be thought of as themselves included within a broader kind of necessity, which I call “general metaphysical” necessity. I suggest that future research should aim to match modal pluralism with a corresponding non-uniform modal epistemology, with different means and methods for modal knowledge, depending on the different modal sub-fields.


Edited collection: 

  • Special issue of Synthese on “New Directions in the Epistemology of Modality” (forthcoming)


Here is how I see the space of metaphysical necessity: