Deemed irrational today, discarded as a “fallacious myth”, the concept of race retains all its explanatory value in France as well as in Europe, Japan or the United States, on the eve of the Second World War. At the Institut d’ethnologie (Institute of Ethnology), Paul Rivet teaches somatic anthropology, the aim of which is “to establish the diagnosis of the different races”. Following him, the Musée de l’Homme will want to draw up an inventory of human diversity, but without “resorting to racism”. Let us understand, by condemning it as a pernicious “ideology” of which a “neutral”, impartial science can and must do justice. Race without racism? The validity of this inquiry is rarely questioned. Moreover, it corresponds to an intellectual heritage rooted in the already ancient history of the Jardin des Plantes. Criticized, though always accepted, the rhetoric of race represents, with hindsight, the blind spot in the legitimation process of scholarly ethnology. These paradoxes well deserve close examination.