Today's political debate seems frozen in time, pitting the party of social justice against the party of economic liberty. The contours of the debate were set as early as the first half of the 20th century, with the Progressive and New Deal challenges to laissez-faire economics, though some people might locate the roots of the debate much earlier—say, in Karl Marx's critique of commercial society, or even Rousseau's. To discover when this debate took its modern form, we need look no further back than the 1970s.

It was in 1971...