Abstract

John Stuart Mill's harm principle holds that an individual's freedom can only be restricted to prevent harm to others. However, there is an important ambiguity between a strong version, which limits legitimate interference to self-defense and therefore prohibits society from protecting third parties (those who are not its members), and a narrow version, which grants any society universal jurisdiction to prevent nonconsensual harms, no matter who is harmed. Mill sometimes appeals to the strong harm principle to preclude interference, but elsewhere endorses measures (including humanitarian foreign intervention and animal cruelty laws) to protect third parties, suggesting that he subscribes only to the weak harm principle. This ambiguity regarding who it is that society has standing to protect has important implications for the scope of individual freedom.