John Stuart Mill (1806–73) was born in London, His father, James Mill, was a friend of Bentham and of Ricardo and did important work himself in psychology and political science. As John Stuart Mill explains in his autobiography, he was educated at home by his father, starting Greek at age 3 and Latin at age 8. By age 13 Mill had been through a complete course in political economy. Mill spent most of his life working for the East India Company. His Principles of Political Economy (1848) was the nineteenth century's most influential text in economics, and his A System of Logic (1843) was the century's most influential text in logic and the theory of knowledge. His essays on ethics and contemporary culture, such as Utilitarianism and On Liberty, continue to be extremely influential. Mill was an early defender of women's rights and of a moderate democratic socialism. The following selection is an abridgment of Mill's “On the Definition of Political Economy and the Method of Investigation Proper to It.” Approximately the first quarter of the essay, in which Mill discusses the definition of economics, is omitted.