Harm Principle
The harm principle, articulated by John Stuart Mill in his essay On Liberty, posits that the only legitimate reason for interfering with an individual's liberty is to prevent harm to others. Mill distinguishes between self-regarding actions, which affect only the individual acting, and other-regarding actions, which affect others. When actions cause harm to others, external authority, such as the state, may justifiably intervene. However, interference should occur only in cases of serious harm; minor inconveniences should be addressed through social means rather than legal coercion.
Mill advocates for a minimal role of external authority, safeguarding personal freedoms unless serious harm to others necessitates intervention. For example, playing loud music may disturb neighbors but usually warrants only social disapproval, not legal penalties. This principle has profound implications for the understanding of freedom and individual rights, encouraging a careful balance between freedom, social order, and the prevention of harm.