Karl Popper is the most quoted representative of the Enlightenment in this century. He is known as a social philosopher through "The Open Society and Its Enemies" and as a philosopher of science with "The Logic of Scientific Discovery." In addition to these two books, he has provided insights or critiques in countless others, in lectures and essays ranging from classical philology to quantum physics and biochemistry; he has consistently demonstrated how to present difficult theoretical problems in simple, clear language. The Popper Reader is a cross-section of his work and showcases the remarkable unity in Popper's thinking amidst the diversity of issues addressed.