entelecheia

Entelecheia, or entelechy, is a philosophical term originating in ancient Greek thought. The word comes from en (in, within) and telos (end, purpose), with an ending that suggests “having” or “holding” the end within. In English, entelechy describes the realization of potential into actuality—the inner principle by which a thing develops toward its natural end.

In Aristotle’s philosophy, entelechy is closely tied to his hylomorphic account of nature. Substances are composites of matter and form, and the form provides the internal principle that actualizes potential. Entelechy is the complete realization of a thing’s inherent purpose or end; it is the form that makes an organism or object what it is from within. For example, the entelechy of a seed is the mature plant it is meant to become.

Historically, entelechy functioned as a key concept in teleology and biology within Aristotelian and medieval thought. It was employed to explain the apparent directionality of natural processes. In later periods, mechanistic science often rejected entelechy as a non-empirical principle, though vitalist theorists such as Hans Driesch revived discussions of an organizing inner principle in living beings, sometimes using entelechy as a metaphor.

Today, entelechy remains primarily a historical or theoretical term. It is invoked in discussions of potentiality, actuality, and final causes, rather than as a testable scientific hypothesis. Related concepts include telos, teleology, and hylomorphism.