The term "metaphysics" originally referred to the writings of Aristotle that came after his writings on physics, in the arrangement made by Andronicus of Rhodes about three centuries after Aristotle's death. Traditionally, metaphysics refers to the branch of philosophy that attempts to understand the fundamental nature of all reality, whether visible or invisible. It seeks a description so basic, so essentially simple, so all-inclusive that it applies to everything, whether divine or human or anything else. It attempts to tell what anything must be like in order to be at all.

A more commonly, popular, usage of metaphysics includes a wide range of controversial phenomena believed by many people to exist beyond the physical, as in mysticism or occultism.

Frans Hals. Young manwith a Skull. c.1626