John Stuart Mill was born in London on May 20, 1806. He was born into one of the most influential intellectual circles of all time. His father, James Mill, was a close friend and collaborator with Jeremy Bentham, the apostle of utilitarianism. Bentham was already famous, having published his An Introduction to the Principles of Morals and Legislation, the groundwork for utilitarianism, during the 1780s. James Mill himself would later gain fame for writing important books on economics, the theory of mind and a history of India. Their intimate circle included such luminaries as the economist, David Ricardo, who had been a neighbor of the Mills, and John Austin, the first important legal positivist in the Anglo-American tradition.