"Innovation is like a bush fire that burns brightly for a short time, then dies down before flaring up somewhere else," says Matt Ridley, whose new book chronicles the history of prosperity. "It used to be popular to argue that the European scientific revolution of the 17th century unleashed the rational curiosity of the educated classes, whose theories were then applied in the form of new technologies, which in turn allowed standards of living to rise. But," Ridley says, "history shows this account is backward. Few of the inventions that made the industrial revolution owed anything to theory."