A deep and widespread crisis affects modern economic theory, a crisis that derives from the absence of a vision--a set of widely shared political and social preconceptions--on which all economics ultimately depends. This absence, in turn, reflects the collapse of the Keynesian view that provided such a foundation from 1940 through the early 1970s, comparable to earlier visions provided by Smith, Ricardo, Mill, and Marshall. The unraveling of Keynesianism...