Potentiality, Modality, And Time

Barbara Vetter's project in Potentiality is to articulate and defend a dispositionalist theory of modality based on potentialities. My focus is on the metaphysics of her positive theory. I consider one of Vetter's main targets, David Lewis's theory of possible worlds, and use it to distinguish what I call "de re first" approaches from "de dicto first" approaches. This way of framing the disagreement helps shed light on what their respective accounts can intuitively accomplish. In particular, I introduce objections to Vetter's requirement that the grounds of de dicto modal truths must be routed through time. I also suggest an alternative de ditto first approach that Vetter does not consider, one which does not come saddled with Lewis's ontology or with Vetter's issues with de dicto modal truths. Rather, on incompatibilism, modality is grounded on second-order relations between (nonpotentialist) properties, e.g. incompatibility or entailment. Defenders of de dicto first approaches, including incompatibilism, can better account for such de ditto modal truths, thus undermining some of the intuitive appeal of Vetter's theory.