Thomas Samuel Kuhn (1922-1996)  

He received a Ph. D. in physics from Harvard University.

Of the five books and countless articles he published, Kuhn's most renown work is The Structure of Scientific Revolutions, which he wrote while a graduate student in theoretical physics at Harvard. Initially published as a monograph in the International Encyclopedia of Unified Science, it was published in book form by the University of Chicago Press in 1962. It has sold some one million copies in 16 languages and is required reading in courses dealing with education, history, psychology, research, and, of course, history and philosophy of science. 

Throughout thirteen succinct but thought-provoking chapters, Kuhn argued that science is not a steady, cumulative acquisition of knowledge. Instead, science is "a series of peaceful interludes punctuated by intellectually violent revolutions," which he described as "the tradition-shattering complements to the tradition-bound activity of normal science." After such revolutions, "one conceptual world view is replaced by another."

Although critics chided him for his imprecise use of the term, Kuhn was responsible for popularizing the term paradigm, which he described as essentially a collection of beliefs shared by scientists, a set of agreements about how problems are to be understood. According to Kuhn, paradigms are essential to scientific inquiry, for "no natural history can be interpreted in the absence of at least some implicit body of intertwined theoretical and methodological belief that permits selection, evaluation, and criticism." Indeed, a paradigm guides the research efforts of scientific communities, and it is this criterion that most clearly identifies a field as a science. A fundamental theme of Kuhn's argument is that the typical developmental pattern of a mature science is the successive transition from one paradigm to another through a process of revolution. When a paradigm shift takes place, "a scientist's world is qualitatively transformed [and] quantitatively enriched by fundamental novelties of either fact or theory."