 In practice, most formulations of physicalism include both modal and non-modal elements at some level. Proponents of modal formulations often end up appealing to something non-modal in the course of elaborating and defending their view. Non-modal versions are usually interpreted so that they have the same modal consequences as modal versions. Nevertheless, the issue of whether to answer the completeness question by appealing to modal or non-modal ideas has proved as controversial as any in the literature on what physicalism is (for overviews, see Rabin 2020, Elpidorou 2018a, Tiehen 2018). In what follows, we will first look at an influential modal answer to the completeness question, which appeals to supervenience, and then turn to several non-modal alternatives.