Dispositionalism and the Modal Operators

Actualists of a certain stripe hold that metaphysical possibility and necessity are grounded in the powers of actual things. I shall refer to this theory as dispositionalism for brevity. At a first pass, , if true, is made true by powers certain actual things have, or had, such that the manifestations of those powers would have resulted in or constituted my being a dancer. It need not be the case that I alone have the powers in question. Perhaps some of the relevant powers belong to dance teachers I never had; or to music I never heard; perhaps they are powers to bring about mutations in my DNA prior to birth, such that had those powers manifested, I would have been less clumsy and more inclined to dance than I actually am. Given dispositionalism, the truthmakers of true modal propositions are the powers of actual things. Dispositionalists are, to borrow Contessa’s phrase, hardcore actualist, in that they seek to explain modality without possible worlds—going directly, so to speak, from the powerful to the possible. The resulting theory is non-reductive, in that the explanans are themselves, in a sense, irreducibly modal. We might say that powers are essentially such as to manifest, producing tokens of their manifestation types, under characteristic stimulus conditions. Or—if this is different—we could say that powers are, of their nature, primitive truthmakers of a range of counterfactuals relating them to their stimuli and manifestations. It is now customary to deny that powers have non-powers as stimulus