Physical modality, laws, and counterfactuals

Standard philosophical accounts attempt to understand physical modality either in terms of special metaphysical entities and relationships (“relations between universals”, “powers”, “dispositions”) or in terms of the organization of non-modal information, as in Best Systems Analysis. This paper defends an alternative to both these approaches in which invariance and various independence conditions play a central role. The methodological importance of separating law-claims from claims about initial and boundary conditions is highlighted