 We can cast arguments for grounding in terms of theoretical roles in addition to those specified by the unity, explanation, and priority arguments as well. Some, for example, claim that the thesis of physicalism (roughly, the view that the world is ultimately physical in nature) is usefully formulated in terms of grounding (Block 2015; Dasgupta 2014a; Schaffer 2017b). With respect to physicalism about the mental in particular (roughly, the view that mental phenomena are nothing over and above physical phenomena), a simple grounding-theoretic formulation of the view is this: the mental facts are grounded by (non-mental) physical facts (perhaps together with other non-mental facts such as indexical and totality facts). It’s by now a familiar idea that purely modal formulations of physicalism are inadequate, as there are coherent versions of dualism that such formulations don’t rule out (Horgan 1993, 2006). Hence, one point in favor of appealing to grounding in this context is that grounding isn’t a purely modal notion. And Block (2015) argues that even physicalism formulated in terms of a priori entailment faces the same problem, pointing to a particular grounding formulation of physicalism as the way to resolve the issue.