Academic philosopher, logician, public intellectual, educator, political activist, and freethinker, Bertrand Russell was and remains a colossus. No other single philosopher in the last 200 years can be said to have created so much and influenced so many. His Principia Mathematica, written with A. N. Whitehead, ranks as one of the greatest books on logic since Aristotle. His philosophical work on language, meaning, logic, mind, and metaphysics formed the basis of 20th-century philosophy. Russell was active in numerous political movements of liberation and peace, and his popular writings,...