John Stuart Mill (20 May 1806 - 8 May 1873) was an English philosopher, political economist and civil servant. One of the most influential thinkers in the history of liberalism, he contributed widely to social theory, political theory and political economy. Dubbed "the most influential English-speaking philosopher of the nineteenth century", Mill's conception of liberty justified the freedom of the individual in opposition to unlimited state and social control. Mill was a proponent of utilitarianism, an ethical theory developed by his predecessor Jeremy Bentham, and contributed significantly to the theory of the scientific method.