This is a uniquely comprehensive introduction to the work of the American philosopher John Rawls (1921-2002), who transformed contemporary political philosophy. In the 1950s and 1960s, political philosophy seemed to have reached a dead end characterized by a loose predominance of utilitarian theses. Rawls's conception of liberalism placed civil liberties and social justice at its core, and his extraordinary influence has only been confirmed by the extent of the criticism he has provoked.