 Kuhn’s work called attention to what he called “the essential tension” between tradition and innovation (Kuhn 1959, 1977a). While he initially claimed that his model applied only to mature natural sciences such as physics, chemistry, and parts of biology, he believed that the essential tension point applies, in varying degrees, to all enterprises that place a premium on creative innovation. His work thereby raises interesting questions, such as which kinds of social structures make revolution necessary (by contrast with more continuous varieties of transformative change) and whether those that do experience revolutions tend to be more progressive by some standard.