John Stuart Mill (1806-1873), British philosopher, economist, moral and political theorist, and administrator, was the most influential English-speaking philosopher of the nineteenth century.e was the eldest son of James Mill, a Scotsman who had come to London and become a leading figure in the group of philosophical radicals which aimed to further the utilitarian philosophy of Jeremy Bentham. John Stuart Mill's mother was Harriet Barrow, who seems to have had very little influence upon him.