 Finally, there are viable approaches to metaphysical explanation that do not fit neatly in either the unionist or separatist camp as it is standardly understood. For instance, Maurin (2019) notes a distinction between those who believe that grounding is “by its nature” explanatory, as opposed to those who maintain that (at best) grounding has certain other features that make it apt to back grounding explanations. Interestingly, the former view (which counts as unionist on Maurin’s classification) does not automatically imply that grounding be grounding explanation (which is required to count as unionist on Raven’s classification). After all, knowledge is by its nature true, but it does not follow that knowledge is truth. Setting aside the less interesting question of how one ought to use the term of art “unionism”, Maurin’s proposal—when broadened to metaphysical explanation in general; see Thompson (2019)—shows that there is conceptual space to distinguish the metaphysical and explanatory elements of metaphysical explanation yet without explicitly linking them by appeal to a relation of backing.