This note proposes a deconstruction of the notion of diversity, which is more and more frequently used. This is done by making explicit the historical contexts in which this notion did appear and the social problems it was supposed to solve, with, in this respect, large differences between France and the US. In a second part, the concrete use of this notion is examined: which traits are put forward, in the name of diversity, which groups are labeled as "diverse"...Then, the unintended effects of this labeling process upon individuals are dealt with, as well as the thesis emphasizing the benefits societies may draw from talking in terms of diversity, rather than in terms of equality or inequality. Last, the conclusion underlines the ideological and political dimensions of this rhetoric of diversity, which is based on a choice of one justice model, which should be made explicit.