 Following Raven (2015), who applies the terminology to grounding and grounding explanations in particular, approaches to this fundamental question might be classified with regard to whether they take a “unionist” or “separatist” line. Standardly, unionism about grounding and grounding explanation is the thesis that they are one: to be grounded just is to be metaphysically explained in a distinctive way (e.g., Dasgupta 2014; Jenkins 2013; Litland 2013, 2017; Raven 2012; Rosen 2010; Thompson 2016). (A unionist might also subscribe to the stronger thesis that the expressions “grounded” and “explained in such-and-such distinctive way” are, or at least ought to be, used as synonyms, but that is not essential to how we understand the view here.) Unionists thus owe some account of how the metaphysical and explanatory elements of metaphysical explanation can be held together in a coherent package, or else jettison one element or the other. Separatism about grounding and grounding explanation is the thesis that they are separate, yet grounding explanations nonetheless “track”, or are “backed” or “underwritten” by, instances of grounding (e.g., Audi 2012, Schaffer 2016, Trogdon 2013). Separatists thus owe some account of how that link keeps the metaphysical and explanatory elements of metaphysical explanation from flying off in opposite directions. One might think that the separatist about grounding explanation here incurs no new debt, since separatists about causal explanation must meet an analogous challenge. However, note that the quasi-causal model of metaphysical explanation at play here is far from the only way in which we might model metaphysical explanation (see  §6),  and also that to distinguish causation from causal explanation is itself a substantive commitment.