Historian and philosopher of science, Thomas Kuhn (1922–1996), who was born in Cincinnati, Ohio, on July 18, was perhaps the most influential theorist of science in the second half of the twentieth century. Kuhn received all his degrees (in physics) and his first job at Harvard University, though he failed to be awarded tenure there in 1956, shortly after the departure of his mentor, Harvard President James Bryant Conant. Kuhn was finally tenured at Princeton University in 1964, on the basis of what remains his best known book, The Structure of Scientific Revolutions (1962). In 1979 Kuhn moved to the Massachusetts Institute of Technology (MIT), where he eventually retired as Laurence Rockefeller Professor of Philosophy and Linguistics. Essays from Kuhn's Harvard and Princeton years appear in The Essential Tension (1977). Essays from his MIT years are collected in The Road Since Structure (2000). At the time of his death, in Cambridge, Massachusetts, on June...