 As McLaughlin put it in 1995, a mere supervenience claim does not entail any “in virtue of” claim. Here are a couple of ways to see this. As noted above, for any property F, being F supervenes on being ~F: two things cannot differ with respect to being F without differing with respect to being ~F. But, of course, being ~F does not ground being F, and being F does not ontologically depend on being ~F!