episteme

Episteme is a term in philosophy that denotes knowledge in a structured, justificatory sense, especially knowledge that is systematic or demonstrable. The word comes from Ancient Greek epistēmē, generally translated as knowledge or scientific knowledge, and it is used to distinguish knowledge from doxa, or opinion.

Its classical use appears in Plato and Aristotle. In Plato, epistēmē refers to knowledge that is certain and knowable through rational demonstration, in contrast to sensory opinion. In Aristotle, epistēmē denotes universal, necessary knowledge achieved by demonstration and applicable to the sciences, mathematics, and other rigorous disciplines, as opposed to mere belief.

In modern and postmodern thought, the term has been reworked by Michel Foucault as an episteme: the historical a priori, the overarching set of rules, categories, and assumptions that define what counts as knowledge at a given time. Epistemic shifts between periods—for example, from the Classical to the Modern episteme—reorder what questions are asked and what methods are considered legitimate.

Outside philosophy, episteme appears in discussions of knowledge production, science studies, and critical theory, used to describe the underlying structures that make certain statements thinkable within a culture or discipline.