On Liberty is a philosophical work in the English language by 19th century philosopher John Stuart Mill, first published in 1859. To the Victorian readers of the time it was a radical work, advocating moral and economic freedom of individuals from the state.
Perhaps the most memorable point made by Mill in this work, and his basis for liberty, is that "Over himself, over his own body and mind, the individual is sovereign". Mill is compelled to say this in opposition to what he calls the "tyranny of the majority", wherein through control of etiquette and morality, society is an unelected power that can do horrific things. Mill's work could be considered a reaction to this social control by the majority and his advocacy of individual decision-making over the self. The famous 'Harm Principle' is also articulated in this work: people can do anything they like as long as it does not harm others. All branches of liberalism - as well as other political ideologies - consider this to be one of their core principles. However, they often disagree on what exactly constitutes harm.
On Liberty was an enormously influential work; the ideas presented within it remain the basis of much political thought since. Aside from the popularity of the ideas themselves, it is quite short and its themes easily accessible to a non-expert. (Quote from wikipedia.org)
About the Author
John Stuart Mill (1806 - 1873)
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 a teacher of utilitarianism, an ethical theory developed by his godfather, Jeremy Bentham, although his conception of it was very different from Bentham's.