Mill's defining statement of liberal political philosophy: a sustained argument that the only legitimate reason for society to restrict individual freedom is to prevent harm to others. Everything beyond that — thought, expression, lifestyle, association — belongs to the sovereign domain of the individual. Mill argues for absolute freedom of opinion and discussion (even of false opinions, since their suppression rots intellectual life), for the value of individuality against the tyranny of custom, and for strict limits on government and social coercion. Written with Harriet Taylor, to whom it is dedicated, On Liberty remains the most widely read text in liberal political thought.