In the fall of 1922 Bergson's book Durée et simultanéité, a propos de la theorie d'Einstein (Duration and Simultaneity: Bergson and the Einsteinian Universe) was published. Earlier in the spring Einstein had come to the French Society of Philosophy and briefly replied to a short speech made by Bergson. The book has been often considered as one of his worst, many alleging that his knowledge of physics was insufficient, and that the book did not follow up contemporary developments on physics. (But in "Einstein and the Crisis of Reason," a leading French Philosopher, Maurice Merleau-Ponty, accused Einstein of failing to grasp Bergson's argument. This argument, Merleau-Ponty claims, which concerns not the physics of special relativity but its philosophical foundations, addresses paradoxes caused by popular interpretations and misconceptions about the theory, including Einstein's own.) It was not published in the 1951 Edition du Centenaire in French, which contained all of his other works, and was only published later in a work gathering different essays, titled Mélanges. Duration and simultaneity took advantage of Bergson's experience at the League of Nations, where he presided starting in 1920 the International Commission on Intellectual Cooperation (the ancestor of the UNESCO, which included Einstein, Marie Curie, etc.).