 A second problem for grounding physicalism is that the notion of grounding is itself controversial in some quarters. Wilson (2014), for example, points out that grounding per se is similar to supervenience in that it leaves open many of the questions philosophers of mind are interested in, viz., whether the mental exists, whether it is reduced to the physical, and whether it is causally efficacious. She concludes that grounding “cannot do the work” that its proponents want it to do (2014, 542). One might respond that this depends on what work grounding physicalism is supposed to do; indeed, it may be a feature rather than a bug that grounding leaves these things open. But whatever is the truth about this, there is no doubt that the precise contours of the grounding relation are yet to be made out. Hence, the proper assessment of grounding physicalism is at this point a bit unclear (for some further discussion, see, e.g., Berker 2018 and Schaffer 2016). 