  Metaphysics, or alternatively ontology, is that branch of philosophy whose special concern is to answer the question ‘What is there?’ These expressions derive from Aristotle, Plato's student. In a collection of his works, the most detailed treatise on the general topic of things that are comes after a treatise on natural things, ta phusika (from which English derives ‘physics’). Since the Greek for ‘after’ is meta, this treatise is titled ‘Metaphysics’. In that work one finds the famous formula that (first) philosophy studies being—the Greek for which is on—qua being. Hence the account of being is ‘ontology’—the English suffix ‘-ology’ signifying ‘study of’: e.g., biology is the study of living things.