Interdisciplinarity is the connecting up of fields of study that have been separated artificially by disciplinary barriers. In France, one of the key moments of its prehistory was the publication of the Encyclopédie, edited by Diderot and d’Alembert; its history itself began with Henri Berr’s creation of the Centre international de synthèse in 1925. During the last three decades of the twentieth century, interdisciplinarity gave rise to a number of scientific research programs. It has also been provided with different yet parallel institutional frameworks at French grandes écoles, universities, and the Centre national de la recherche scientifique, France’s largest governmental research organization. As a mindset associated with a commitment to openness, it involves a form of mental conversion that has only, at present, been partially achieved.