On Liberty

On Liberty by John Stuart Mill (1859)

"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." The foundational text of classical liberalism and individual rights.

Historical Significance:
Published in 1859 — the same year as On the Origin of Species — Mill's essay is the most important defense of individual liberty in Western philosophy. Mill argued that society has no right to restrict individual behavior unless it harms others (the "harm principle"). He defended freedom of speech even for opinions society finds repugnant, arguing that suppressing ideas — even wrong ideas — harms everyone. Written partly in collaboration with his wife Harriet Taylor Mill, On Liberty influenced the development of civil liberties law worldwide. The harm principle is cited in Supreme Court decisions and human rights charters to this day.

This public domain classic was originally published in 1859. Free to read and share.