David Ricardo (1772-1823) was the son of a wealthy English capitalist who had made a fortune on the stock exchange after migrating to England from Holland. The younger Ricardo was even more successful on the stock exchange than his father had been, becoming a very wealthy man before he was thirty. In 1799 he read Adam Smith’s The Wealth of Nations, and from that time until his death he divided his time between studying and writing about issues in political economy and enlarging his fortune. It is generally agreed that he was the most rigorous theoretician of the classical economists. His ability to construct an abstract model of how capitalism worked and then to depict all of its logical implications was unsurpassed in his own time. Furthermore, his economic theorizing established a style of abstract deductive economic models that has dominated economic theory down to the present. Like Adam Smith, he was to exert a powerful influence on both the radical Marxist and the conservative neoclassical traditions of economic theorizing throughout the remainder of the nineteenth and twentieth centuries. Unquestionably, he has been one of the five or six most influential economists of modern times.