The ideas of economists and political philosophers, both when they are right and when they are wrong, are more powerful than is commonly understood. Indeed the world is ruled by little else. Practical men, who believe themselves to be quite exempt from any intellectual influences, are usually the slaves of some defunct economist.
—The General Theory of
Employment, Interest and Money
Concluding his most important book with those words in 1935, John Maynard Keynes was confident that he had laid down a philosophy that would move and change men's affairs. Today,...