Abstract

According to the principle of conditional power aggregation (CPA), conditional powers conjoin when the properties that bestow them conjoin. Sophie Gibb has argued that CPA is false given Shoemaker’s account of conditional powers and that this leads to a problem for his account of subset realization. In short: If CPA is rejected, subset realization fails to be an entailment relation, in which case it cannot provide a basis for non-reductive physicalism. I defend the subset account against this argument by denying that CPA fails. I argue that (i) Shoemaker’s account of conditional powers does not warrant a rejection of CPA, (ii) his account is incomplete and should be supplemented with a further sufficient condition for when a property bestows a conditional power, and (iii) this further sufficient condition supports CPA.