 In  §2,  we canvassed some putatively different forms of metaphysical explanation. But how many are there in fact? Monists about metaphysical explanation think that there is just one, whereas pluralists think that there are many. There are various different respects in which one might be a monist or a pluralist. For example, one might think that metaphysical explanations derive their explanatory power from any of a number of non-causal dependence relations (e.g., Thompson 2019), but that all metaphysical explanations derive their explanatory power in the same way. This would be a pluralism in one sense, because various kinds of relations produce metaphysical explanations, but a monism in another because all metaphysical explanations have the same form. A more monistic spin on such an account would hold that grounding relations produce metaphysical explanations, but that there are various grounding mechanisms (e.g., Trogdon 2018). If the source of some metaphysical explanations is relational but the source of others is to be found in the essences of things, this is another version of this type of “lightweight” pluralism.