Thomas Kuhn

Thomas Kuhn was an American philosopher and historian of science whose Structure of Scientific Revolutions transformed our understanding of how science progresses. He introduced the concept of the paradigm shift — the idea that science advances through revolutionary breaks rather than gradual accumulation.

Kuhn's account of normal science as puzzle-solving within a paradigm, and of scientific revolutions as paradigm changes driven by anomalies and crises, challenged both positivist and Popperian models of scientific rationality. His concept of incommensurability — that competing paradigms cannot be straightforwardly compared — generated ongoing debate about scientific progress and relativism.