The Hungarian sociologist Karl Polanyi, who eventually settled in Canada, was one of the most prescient and persuasive political economists of the mid-twentieth century. In pioneering historical analyses, he argued that a “great transformation” took place in the early nineteenth century that systematically destroyed the premodern systems of welfare and social justice and established unfettered free markets—and thus reduced individual laborers to expendable commodities. His basic premise, drawn from Marxist theory, was that unregulated markets are based on political coercion. They also generate inequality, which those who support market liberalization foster misleading ideologies to justify. After World War II, Polanyi, like most social democrats, supported political reforms that would institute the redistribution of wealth and impose restrictions on private property rights, thereby reversing the great transformation. If such premises and prescriptions seem old-fashioned, it is because we have moved recently toward a more globally integrated, privatized, financialized, and in some respects unequal and socially segregated world—changes accompanied by a partial return to nineteenth-century values. That reversal would surely have shocked and baffled Polanyi, but it also serves to render this clear explication of his provocative ideas all the more timely and relevant.