 Third, although a useful starting point, it is not entirely uncontroversial to say that every form of metaphysical explanation is a form of non-causal explanation. Take (2), which many take to be a case of  metaphysical grounding,  the relationship by which more fundamental facts somehow “give rise to” less fundamental ones. Although most theorists classify grounding as non-causal, A. Wilson (2018) argues that grounding is literally a form of “metaphysical causation”, from which it would seem to follow that (2) is a form of causal explanation (see  §6.1  below). Or take Bennett (2017: 61–62), who claims that causation is an instance of what she calls “metaphysical building”, every instance of which is an instance of metaphysical explanation (at least if understood as a wholly objective phenomenon, rather than one requiring that certain epistemic conditions hold; see  §5  for more on realist vs. antirealist conceptions of metaphysical explanation). Nor is our starting point, useful as it is, entirely unproblematic. Consider another example: