Grounding, physicalism, and the explanatory gap

Contemporary metaphysics is marked by a revived interest in the notion of ground. Some philosophers have even suggested that this is the notion needed to best formulate physicalism---the view that the mental is “nothing over and above” the physical. For there are reasons to think that physicalism understood as a grounding thesis (Grounding Physicalism) has advantages over the traditional options. In short, the appeal of Grounding Physicalism is that it promises to occupy a middle position between reductive and non-reductive versions of physicalism. Despite its initial appeal, I argue that a new spin on a common objection to physicalism---that it leaves an “explanatory gap”---undermines the enthusiasm for Grounding Physicalism. The explanatory gap problem has been heavily discussed, but usually with the assumption that physicalism is an identity thesis. By contrast, I focus on Grounding Physicalism and argue that it leaves an explanatory gap---moreover, one that cannot be addressed in the usual way. I then argue that this creates a dilemma for the Grounding Physicalist.Philosoph