John Stuart Mill (1806-1873) was a 19th-century British politician and political philosopher. Born and raised in London, Mill had a brilliant mind: He learned Greek starting at the age of three, and Latin and algebra when he was eight. He went on to serve the University of St. Andrews as Rector, and held various elected public positions. As a liberal political theorist he was deeply concerned about the role of government in promoting human welfare.
In his book, Utilitarianism, Mill introduced the idea that morally sound actions lead to outcomes that offer the greatest possible happiness to the greatest possible number of people. His idea can be rephrased this way: What is morally sound is that which produces the greatest good to the greatest extent possible.
Mill's utilitarianism was criticized at the time as potentially promoting a tyranny of the majority. Mill disputed this assertion, stating that "the greatest good for the greatest number" could only be correctly discerned in a climate where human liberty and rational judgment were valued. Mill was ahead of his time in many ways, speaking out forcefully against slavery, against censorship, and against the social construction of gender roles that oppressed women, basing those positions on a utilitarian ethical framework.
Mill's strong support for the rights of the oppressed highlights his position that to truly determine "the greatest good for the greatest number" in any given situation it is necessary to include those who are disenfranchised or in a minority position in the rights and privileges enjoyed by the majority. For him, such inclusion was an essential requirement of both liberty and justice, which he viewed as "good."
Mill was deeply influenced by the earlier work of English legal scholar Jeremy Bentham (1748-1832), who was a Unitarian, but Mill was not affiliated with any religion. After John Stuart Mill's death, there was discussion of his religion in the Unitarian Review and Religious Magazine, which stated, "Mr. Mill [son of John Stuart Mill] testifies that his father died without the smallest wavering in his convictions on the subject of religion, died, that is to say, believing as to God and a life hereafter, that no grounds exist for any belief whatsoever; and holding in hatred . . . not this or that religion, but religion itself as a hindrance to the world's comfort and improvement." (Charles Lowe, "The Religious View of John Stuart Mill," Unitarian Review and Religious Magazine, Vol. 1 (1874).)