Teleology

Teleology is the study of purposes, goals, ends and functions. Intrinsic or immanent teleology is concerned with cases of aiming or striving towards goals; extrinsic teleology covers cases where an object, event or characteristic serves a function for something.

Teleological explanations attempt to explain X by saying that X exists or occurs for the sake of Y. Since the question ‘For what purpose… ?’ may be construed either intrinsically or extrinsically, such explanations split into two broad types: those that cite goals of an agent, and those that cite functions.

The history of Western philosophy and science has been characterized by major debates about the logic, legitimacy and proper domains of these types of explanation. They still raise problems in contemporary biology and psychology. The modern debates have progressed considerably from the earlier ones, although continuities do exist.