Investigating Non-philosophers’ Judgements about the Asymmetry of Metaphysical Explanation

It is often supposed that metaphysical explanation is asymmetric: that for all x and y, if x metaphysically explains y, then y does not metaphysically explain x. Even amongst those who hold that metaphysical explanation is not asymmetric, but nonsymmetric, it is assumed that a relatively small number of particular explanations are symmetric: by and large, if x metaphysically explains y, then y does not metaphysically explain x. Both parties agree that as a matter of fact we at least typically judge that if x metaphysically explains y, then y does not metaphysically explain x. There has, however, been no empirical investigation of our judgements on these matters, beyond the armchair reflections of philosophers. This paper investigates our judgements and finds that in every case participants were presented with, a majority judged that x metaphysically explained y, and that y metaphysically explained x. This gives us reason to conclude not only that metaphysical explanation is not asymmetric, but also that it has many more symmetric instances than philosophers have supposed. Indeed, the evidence we collected is consistent with metaphysical explanations being symmetric. We evaluate the upshots of this research for theorising about metaphysical explanation