 What is the relation between physicalism so defined, which we might call necessity physicalism, and supervenience physicalism? At least if necessitation is understood as a sort of entailment, then these are not equivalent; for discussion of this point, see  supervenience.  However, (1) and (2) are clearly similar, in particular they are modal formulations of physicalism. In what follows we will concentrate on supervenience physicalism, but what we will say will apply also to necessity physicalism.