John Locke (1632-1704)

English philosopher and author of Second Treatise on Civil Government who was a major figure in the history of political theory and philosophy. By explicitly stating that his justification of liberty is utilitarian in principle in On Liberty, is stating that that his defense of liberty is not be based on natural rights, such as those proposed by Locke.

Jean-Jacques Rousseau (1712-1788)

Eighteenth century European political philosopher whose ideas on liberty and freedom had wide influence during is own time and after, including on John Stuart Mill—including the title concept in Rousseau’s Social Contract essay that defines rights as those things that people would have agreed to have protected by society, and duties as those things people would have agreed to take on as obligations, had they been present at the formation of the state.

Popular pages: On Liberty