There is no better place to begin a study of Kuhn’s developed epistemology of science than with his remarks on scientific revolutions. This is so for three reasons. First, revolutions figure so importantly in Kuhn’s account of scientific change. It is their structure that he was trying to elucidate in The Structure of Scientific Revolutions. And it is their existence which supports his non-cumulative account of scientific knowledge. Second, revolutionary scientific changes were the focus of much of the criticism against Kuhn’s account of science. According to Kuhn, the development of scientific knowledge is punctuated by scientific revolutions, dramatic and unsettling events that undermine the traditional picture of the growth of scientific knowledge as cumulative. Such an account of science was widely perceived as posing a significant threat to the rationality of science. Third, in his later work Kuhn develops a new definition and understanding of scientific revolutions, one designed to avoid the pitfalls of his earlier characterization of scientific revolutions as paradigm changes.

In this chapter, I examine Kuhn’s developed account of scientific revolutions. He no longer identifies revolutions as paradigm changes. Rather, a revolution involves the replacement of an accepted scientific lexicon or taxonomy with a new one. Such changes are precipitated by crisis in the research community. And the resolution of the dispute between advocates of the competing theories or lexicons cannot be resolved by means of shared standards. Importantly, Kuhn regards the research community, or scientific specialty, as the locus of theory change and scientific change in general. Revolutions are not just changes in individual scientists’ beliefs. This helps us understand why Kuhn stopped comparing revolutionary changes to gestalt shifts. Research communities are incapable of experiencing gestalt shifts. Hence, a revolutionary change occurs only when a research community replaces the theory with which it works with another theory. This is one important respect in which Kuhn’s epistemology of science is aptly described as a social epistemology.