science class for humanities undergraduates with a focus on historical case studies. Kuhn later commented that until then, "I'd never read an old document in science." Aristotle's Physics was astonishingly unlike Isaac Newton's work in its concepts of matter and motion. Kuhn wrote: "as I was reading him, Aristotle appeared not only ignorant of mechanics, but a dreadfully bad physical scientist as well. About motion, in particular, his writings seemed to me full of egregious errors, both of logic and of observation." This was in an apparent contradiction with the fact that Aristotle was a brilliant mind. While perusing Aristotle's Physics, Kuhn formed the view that in order to properly appreciate Aristotle's reasoning, one must be aware of the scientific conventions of the time. Kuhn concluded that Aristotle's concepts were not "bad Newton", just different. This insight was the foundation of The Structure of Scientific Revolutions. Prior to the publication of Kuhn's book, a number of ideas regarding the process of scientific investigation and discovery had already been proposed. Ludwik Fleck developed the first system of the sociology of scientific knowledge in his book The Genesis and Development of a Scientific Fact (1935). He claimed that the exchange of ideas led to the establishment of a thought collective, which, when developed sufficiently, served to separate the field into esoteric (professional) and exoteric (laymen) circles. Kuhn wrote the foreword to the 1979 edition of Fleck's book, noting that he read it in 1950 and was reassured that someone "saw in the history of science what I myself was finding there." Kuhn was not confident about how his book would be received. Harvard University had denied his tenure a few years prior. However, by the mid-1980s, his book had achieved blockbuster status. When Kuhn's book came out in the early 1960s, "structure" was an intellectually popular word in many fields in the humanities and social sciences, including linguistics and anthropology, appealing in its idea that complex phenomena could reveal or be studied through basic, simpler structures. Kuhn's book contributed to that idea. One theory to which Kuhn replies directly is Karl Popper's "falsificationism", which stresses falsifiability as the most important criterion for distinguishing between that which is scientific and that which is unscientific. Kuhn also addresses verificationism, a philosophical movement that emerged in the 1920s among logical positivists. The verifiability principle claims that meaningful statements must be supported by empirical evidence or