Richard Feynman was a fox, not a hedgehog: he did not know one big thing; instead, he knew many things. He was an inspired tinkerer, a Thomas Edison of theoretical science. Still, like Leo Tolstoy, he yearned to be a hedgehog. Feynman’s vision was like Tolstoy’s: “scrupulously empirical, rational, tough-minded and realistic. But its emotional cause is a passionate desire for a monistic vision of life on the part of the fox bitterly intent on seeing in the manner of the hedgehog.” This difference extends to method and attitude. While the great physicist Hans Bethe, Feynman’s frequent working companion at Los Alamos, proceeded deliberately in any argument between them, Feynman “was as likely to begin in the middle or at the end, and jump back and forth until he had convinced himself he was right (or wrong).” It was a contest between “the Battleship and the Mosquito Boat,” a small, lightly armed torpedo vessel. From 1948 to 1958, Feynman enjoyed triumph after triumph. To a former student, Koichi Mano, Feynman wrote: “You met me at the peak of my career when I seemed to you to be concerned with problems close to the gods.” Working on these problems, Feynman reflects a general conviction typical of successful scientists. Another scientist says what Richard Feynman might have: “There’s nothing I’d rather do. In fact my boy says I am paid for playing. He’s right. In other words if I had an income I’d do just what I’m doing now. I’m one of the people who has found what he wanted to do. At night when you can’t sleep you think about your problems. You work on holidays and Sundays. It’s fun. Research is fun. By and large it’s a very pleasant existence.” Problems close to the gods are their gift, but the gods are capricious. This is why for many geniuses, being a genius is a career as brief as an athlete’s. For most, as for Feynman, a dreaded day arrives: the great insights stop coming. The marvelous decade having passed, Feynman tells his student Mano that he turned to “innumerable problems you would call humble.”