A telos (from the Greek word for "end", "purpose", or "goal," pronounced TEE-los) is an end or purpose, in a fairly constrained sense used by philosophers such as Aristotle. It is the root of the term "teleology," roughly the study of purposiveness, or the study of objects with a view to their aims, purposes, or intentions. Teleology figures centrally in Aristotle's biology and in his theory of causes.