 John Rawls (b. 1921, d. 2002) was an American political philosopher in the liberal tradition. His theory of justice as fairness describes a society of free citizens holding equal basic rights and cooperating within an egalitarian economic system. His theory of political liberalism explores the legitimate use of political power in a democracy, and envisions how civic unity might endure despite the diversity of worldviews that free institutions allow. His writings on the law of peoples set out a liberal foreign policy that aims to create a permanently peaceful and tolerant international order.