Mill Quote on the Harm Principle: Power to Prevent Harm to Others

Quote

"The only purpose for which power can be rightfully exercised over any member of a civilized community, against his will, is to prevent harm to others." — John Stuart Mill, On Liberty (1859)

Author

John Stuart Mill (1806–1873) was a British philosopher, economist, and reformer, and one of the leading exponents of utilitarianism. On Liberty is his most famous defense of individual freedom.

Source

The quotation opens the second chapter of On Liberty, where Mill states the harm principle — the famous "one very simple principle" that governs the rightful limits of society's power over the individual.

Context

The quotation is the definitive statement of the harm principle, also known as the liberty principle. Mill is concerned with two threats to freedom: the tyranny of the state and the more insidious tyranny of prevailing opinion. He argues that the individual is sovereign over his own body and mind, and that the only legitimate reason for society to interfere with his liberty is to prevent harm to others. Harm to oneself, or conduct that harms no one else, is not a sufficient ground for interference. The principle thus condemns paternalism and moral censorship, and it grounds the widest possible freedom of thought, speech, and action consistent with the equal freedom of others.

Meaning

The quotation draws the exact boundary of legitimate coercion. Its key move is the restriction of interference to the single end of "prevent harm to others": the person's own good, physical or moral, is not a sufficient warrant. The phrase "against his will" signals that the principle governs coercion, not persuasion or advice — we may argue, reason, and remonstrate with someone, but we may not compel them for their own sake. This is the foundation of Mill's commitment to prudence and justice, and it has shaped the modern understanding of a good life lived freely. The harm principle is one of the cornerstones of the Ethics & Wisdom collection.

Related Wisdom

The quotation grounds Mill's account of prudence and justice, and it connects to the wider wisdom tradition's concern with the conditions of a good life and the rightful limits of coercion.