Teleology (from τέλος, telos, 'end', 'aim', or 'goal', and λόγος, logos, 'explanation' or 'reason')[1] or finality[2][3] is a branch of causality giving the reason or an explanation for something as a function of its end, its purpose, or its goal, as opposed to as a function of its cause.[4]
A purpose that is imposed by human use, such as the purpose of a fork to hold food, is called extrinsic.[3]Natural teleology, common in classical philosophy, though controversial today,[5] contends that natural entities also have intrinsic purposes, regardless of human use or opinion. For instance, Aristotle claimed that an acorn's intrinsic telos is to become a fully grown oak tree.[6] Though ancient atomists rejected the notion of natural teleology, teleological accounts of non-personal or non-human nature were explored and often endorsed in ancient and medieval philosophies, but fell into disfavor during the modern era (1600–1900).
^ abDubray, Charles. 2020 [1912]. "Teleology". In The Catholic Encyclopedia 14. New York: Robert Appleton Company. Retrieved 3 May 2020. – via New Advent, transcribed by D. J. Potter