Few would argue that Richard Feynman was one of the greatest American-born theoretical physicists of the twentieth century, and fewer still would dispute that he was the most iconoclastic. In the words of the eminent mathematician Mark Kac, geniuses are of two kinds: the ordinary, and the magicians. Feynman was a magician of the highest caliber. No one could guess how his mind worked, how he could make transcendental leaps of the imagination so fearlessly...