Bertrand Russell

Russell was an aristocrat (an earl), a logician, a pacifist who went to prison for it in World War I, a public intellectual, a Nobel laureate (for literature, of all things), and the most distinguished English-language philosopher of the early 20th century. With Whitehead he wrote the Principia Mathematica, a heroic three-volume attempt to reduce all of mathematics to logic.

He is one of the founders of analytic philosophy: the conviction that philosophical problems are largely problems of language and logic, and that they can be made tractable by careful logical analysis. His theory of descriptions showed how to handle sentences like "the present king of France is bald" — sentences that seemed to refer to nothing but still looked meaningful. His Russell's paradox broke Frege's logical system on its way to press.

He lived to be ninety-seven. He marched against nuclear weapons in his eighties. He wrote, popularized, agitated, married four times, scandalized everyone. His History of Western Philosophy — opinionated, wrong about half the time, unfailingly entertaining — has been a generation's first encounter with the subject.