Teleology
Teleology (from Greek telos, meaning end or purpose) is the philosophical study of nature by attempting to describe things in terms of their apparent purpose, directive principle, or goal. A purpose that is imposed by a human use, such as that of a fork, is called extrinsic. Natural teleology, common in classical philosophy but controversial today, contends that natural entities also have intrinsic purposes, irrespective of human use or opinion. For instance, Aristotle claimed that an acorn's intrinsic telos is to become a fully grown oak tree.