John Stuart Mill (20 May 1806 – 8 May 1873), British philosopher, political economist, civil servant and Member of Parliament, was an influential liberal thinker of the 19th century. He was an exponent of utilitarianism, an ethical theory developed by Jeremy Bentham, although his conception of it was very different from Bentham's. He was a forceful proponent in the fight for government intervention in social reform. (Summary by Wikipedia)