To introduce my story, I take the reader back to 1962, when the academic world saw the publication of The Structure of Scientific Revolution, by Thomas Kuhn. … Most certainly, it upset my own Logical Empiricist assumptions. It had that effect for two reasons. The first was his claim, vividly documented, that past scientific revolutions were not the unambiguous expression of sheerly logical and experimental factors, rationally played out according to a well-defined methodology. Rather, they were the expression of a variety of nonlogical factors as well: social, psychological, metaphysical, technological, aesthetic, and personal. … The second reason for the ensuing controversy was his claim, also well-documented, that the unit of scientific understanding is not the sentence, or set of sentences, but rather the so-called "paradigm", or family of paradigms.