Metaphysical Foundationalism and the Principle of Sufficient Reason

Abstract There is a ubiquitous claim in the grounding literature that metaphysical foundationalism violates the principle of sufficient reason (PSR) in virtue of positing a level of ungrounded facts. I argue that foundationalists can accept the PSR if they are willing to replace fundamentality as independence with completeness and deny that ground is a strict partial order. The upshot is that the PSR can be compatible with both metaphysical foundationalism and metaphysical infinitism, and so presupposing this fixed explanatory demand need not beg the question in favour of either view.