Bertrand Russell

Bertrand Russell (b. 1872–d. 1970) was arguably the most important philosopher of the 20th century. He was one of the main founders of what came to be known as analytic philosophy, which was preeminent in the English-speaking world throughout most of the 20th century. His most important contributions, especially in the first part of his career, were in logic and the philosophy of mathematics, but he made important contributions to almost all branches of philosophy, especially to epistemology and metaphysics. His philosophy went through a series of fairly rapid changes, which has made it natural to study his work developmentally. He wrote prolifically, much of his early work was extremely technical, and a surprising amount of material was left unpublished by him and has appeared only posthumously in The Collected Papers of Bertrand Russell (Russell 1983–, cited under Primary Sources). As a result, there is no detailed survey of his entire philosophical output by a single author; full-career surveys tend to be either brief or collections of papers, and more substantial commentaries tend to focus on particular periods or topics. Our understanding of Russell’s philosophy has been transformed since his death by the availability of so much new material in his archives. As a result, earlier studies of his work need to be treated with caution. In addition to his philosophical work, Russell wrote even more extensively on matters of social and political concern. He was politically engaged throughout his life, especially in matters relating to war and peace and freedom of the individual. I am grateful to Kenneth Blackwell, Andrew Bone, William Bruneau, Jolen Galaugher, Dustin Olson, Graham Stevens, and the referees for OBO for several useful suggestions.