The cultural impulse to try to anticipate the future, and make sense of apparently random events, is irrepressible. Perhaps the most famous of all sites of prediction is the Oracle of Delphi. How the world of antiquity, and particularly the ancient Greeks, tried to foretell the outcome of the present, serves as Esther Eidinow's starting-point for an appraisal of that legacy of forecasting in our own era. Delphi is still invoked when business people discuss future strategy and risk; these is even a strategic planning technique called the "Delphi Method." But the Delphic Oracle is only the best...