A Solution to the Problem of Necessary Perfect Masks

Dispositionalism is the view that it is possible that p iff sometimes, something has an iterated potentiality to be such that p. Recently a formidable challenge has been raised against it: the paradox of necessary perfect masks (Vetter & Busse 2022). A mask is perfect if it guarantees that, come what may, the manifestation will not come about as long as the mask is present, and it is necessary if it cannot be removed or destroyed. This generates a contradiction for Dispositionalism. In this paper, I offer a novel solution to the paradox, which I call the Degree Solution. As the name suggests, it is centred around the role that degrees of potentiality play in grounding modality. My strategy to dispel the paradox comprises of three steps. First, I will argue that degrees of potentialities play a role in grounding modal truths: only non-zero potentialities ground modal truths. Then, I will argue that that degree of potentialities are extrinsic second order properties of potentialities –– and, in particular, that they depend on the modal status of both their stimuli/disposition partners and masks. I will argue that necessary perfect masks reduce the degree of a potentiality to zero, thereby preventing them from grounding a modal truth and preventing the contradiction to arise. Thirdly, I argue that there are zero-degree potentialities, that they are not ad hoc and have genuine explanatory power. They offer the theory important expressive resources to make sense of our intuitions concerning cases of ‘impossible dispositions’ (Jenkins & Nolan 2013) and perhaps also the resources to account for the truth and falsity of some non-vacuous counter-possible and counter-nomic conditionals. Necessary perfect masks are not the ‘big bad bug’ of dispositionalism. On the contrary, taking them seriously leads us to discover new and welcome features of the theory.