The American philosopher whose A Theory of Justice (1971) revived political philosophy as a serious academic discipline, argued that justice requires principles chosen behind a 'veil of ignorance' that generates equal basic liberties and the difference principle — permitting inequality only when it benefits the least advantaged — and whose framework has been the central reference point for liberal political philosophy for fifty years.
A Theory of Justice begins with a sentence that changed political philosophy: 'Justice is the first virtue of social institutions, as truth is of systems of thought.' Rawls then asked: what principles of justice would rational people choose if they didn't know what position they would occupy in society — rich or poor, talented or not, from a favored group or a disadvantaged one? The answer — equal basic liberties, and inequality permitted only when it helps the worst-off — became the most debated framework in political philosophy. Half a century later it still is.