"He's tart, tough-minded, terribly British...an imposing grand master of aphorism, argument and lightning-bolt one-liners." So Newsweek writer wrote of Sir Peter Medawar, the renowned British immunologist. "The most accomplished writer of popular-science essays," declared the Philadelphia Inquirer. Now this Nobel Prize-winning scientist and highly acclaimed author of Pluto's Republic, Aristotle to Zoos, and many other books has written a fascinating...