Paradigm Shift

Kuhn's concept of a revolutionary change in the framework assumptions of a scientific discipline — replacing one 'paradigm' (shared set of exemplars, methods, and worldview) with an incompatible one.

Normal science: within a paradigm, scientists solve 'puzzles' within an accepted framework — they do not question foundational assumptions. Anomalies: observations that resist explanation within the paradigm accumulate. Crisis: when anomalies become too severe, the field enters a period of crisis. Revolution: a new paradigm emerges that resolves the anomalies — but is incommensurable with the old one. Examples: Copernican revolution, Lavoisier's chemistry, Einstein's physics. The most influential concept in 20th-century philosophy of science.