Metaphysics is a branch of philosophy about existence and the nature of things that exist, which is as a whole a theory of reality. Its name is derived from the title of a collection of four texts by Aristotle. Its meaning, though, has become somewhat convoluted over the centuries. The primary concern of metaphysics is with respect to the question of "being, as such", the essence of an object or idea, the basis of the field of ontology. Over time, metaphysics has grown into philosophical branches such as logic and epistemology.
There is a great deal of dispute amongst philosophers, particularly David Hume and his intellectual descendants, that a metaphysics may not be possible. There is an additional dispute over whether metaphysics is capable of saying anything with content, as it concerns itself strictly with abstraction.