The Structure of Scientific Revolutions

by Thomas S. Kuhn

Accepted examples of scientific practice, including laws, theories, applications, experiment, and instrumentation, provide the models that create a coherent tradition and serve as the commitments which constitute a scientific community in the first place. The few sentences just quoted establish the fundamental idea of Structure. Paradigms are integral to normal science, and a normal science, practiced by a scientific community, continues as long as there is plenty to do, open problems which yield to research using methods (laws, instruments, etc.) acknowledged by the tradition. By the end of page 12 we are away to the races. Normal science is characterized by a paradigm, which legitimates puzzles and problems on which the community works. All is well until the methods legitimated by the paradigm cannot cope with a cluster of anomalies; crisis results and persists until a new achievement redirects research and serves as a new paradigm. That is a paradigm shift (in the book, you will find that he more often says “paradigm change,” but shift has proved more catchy).