On Liberty

On Liberty is a foundational text of modern liberalism, presenting the most influential articulation of the harm principle — the idea that the sole legitimate ground for restricting individual freedom is the prevention of harm to others. John Stuart Mill mounted a powerful defense of freedom of speech, thought, and individuality against the twin threats of governmental tyranny and the tyranny of the majority, arguments that remain central to political and legal debate today.

Published in 1859 during the Victorian era, On Liberty addressed the tension between individual liberty and social conformity with a clarity and force that has shaped liberal democratic thought ever since. Mill's arguments have profoundly influenced First Amendment jurisprudence in the United States and remain core reading in political science and law programs around the world.