"To achieve one's secular salvation." As he neared the end of his life, it was with these words that Raymond Aron summarized his intellectual journey in his Mémoires. History was at his life's center. Above all else, the notion of history provided a framework for a philosophy that turned its back on the idealism of the preceding philosophical generation. Instead, it sought to rethink the inscription of the individual in the historical world in light of the tension between freedom and determinism. In both Raymond Aron's World War II participation in the Resistance in London and his ideological positioning during Cold War clashes between supporters of the Soviet Union and defenders of Western democracies, history was one of his works' central themes. In France, he pioneered historical analysis of both international relations and modern societies threatened by nuclear extinction. This critical research continued all the way through the 1970s right up to his 1984 posthumous book Les Dernières Années du siècle. Furthermore, his dialogue with sociology helped him redefine a notion of history that was able to meet the demands of a critical philosophy.