Thomas Phillips · Public domain

Born in London to a Sephardic Jewish family of Portuguese descent, Ricardo made his fortune as a stockbroker financing government debt before turning, in his thirties, to economics. His theory of comparative advantage gave free trade its enduring intellectual justification, and as a Member of Parliament he campaigned against the Corn Laws, arguing that tariffs on grain made food needlessly expensive for the country that imposed them. At twenty-one he eloped with a Quaker and converted to Unitarianism, a decision that estranged him from his family for years.