 Historical interest in metaphysical explanation was not Aristotle’s alone. Philosophers as diverse as Plato, Nāgārjuna, Ibn Sīnā (Avicenna), William of Ockham, Spinoza, Leibniz, Bolzano, Duhem, and Husserl (see Mulligan 2004 and also  related entries  below), among many others, explicitly grappled with questions such as those above, although some in a more skeptical vein than others. Moreover, countless other philosophers both inside metaphysics and out clearly presuppose that the notion is in good standing when discussing the various types of metaphysical explanation that we discuss below. Our goal in the present entry, however, is not to provide a full accounting of how the concept has developed over time—here, we focus on framing the main questions and disputes that emerge when one attempts to state what metaphysical explanation is, exactly, and how it is supposed to work (if at all).