Kuhn, Thomas (1922-1996)

American historian of science noted for The Structure of Scientific Revolutions, one of the most influential works of history and philosophy of the 20th century.

Kuhn introduced the idea of a "Paradigm" which allows only certain kinds of questions to be asked about a science while excluding others, until contradictions build-up to a point where a sudden change of Paradigm takes place, and the whole science is rapidly reconstructed under the "new paradigm". Kuhn developed a kind of sociology of scientific community to study how these paradigms both constrained and promoted the development of scientific knowledge.
After studying Physics at Harvard, Kuhn did his PhD in the history of science and subsequently taught and wrote on the history and philosophy of science at Harvard, the University of California (Berkeley), Princeton and M.I.T. until his retirement in 1991.

In his first book, The Copernican Revolution (1957), Kuhn studied the development of the heliocentric theory of the solar system during the Renaissance. In his landmark second book, The Structure of Scientific Revolutions, he generalised what he described in the first book.

In a conception which is strongly reminiscent of Hegel's conception of the development of knowledge, he argued that scientific research always works within a certain "paradigm," or closed system of concepts and methods which exclude dissident views which cannot be fitted into the system. During such a period of 'normality', researchers simply refine theories and develop their implicaitons; puzzling or anomalous results or facts are simply excluded. Over time, however, the weight of these anomalies builds up and eventually trigger a crisis in which attention is suddenly turned to what was previously ignored, basic assumptions and long-held opinions are overthrown and eventually some new way forward emerges and the old system of ideas falls into disrepute and the whole science is again reworked under the new "paradigm".