The government programme of the Conseil national de la Résistance (National Council of the Resistance), 15 March 1944, included a vast project to reform education that was entrusted to Langevin and WallonWallon, Henri. This was a huge task for an elderly man weakened by the war years. But this responsibility was the outcome of Langevin’s longstanding efforts to change the educational system. Through a survey of his participation in the New Education Movement and contributions to French reform projects in the 1920s and 1930s, this chapter outlines the key ideas that inspired him: developing modern humanities, promoting general culture as a tool to weave the social fabric rather than vocational training and adopting science-based educational methods. Langevin considered such measures to be the only levers in their hands to build up social justice.