From Socrates to Levinas, a short history (in French) of the core of philosophy, the idea of concept. A beautiful course with a deflated ending. Jullien understands the heroism of the concept, but fails to conceive clearly of the crealectics of the concept, between alterity, singularity, on the one hand, and universalisation, identification on the other: an individual can asymptotically embody the concept she created. A concept is a becoming one, a bridge between the universal and the particular, over the Creal.