In this article, we engage in a debate that first took place in France ten years ago, but that has revived today. This debate concerns the question of whether to introduce ethnic categories in statistical surveys in France. There is strong opposition between those who argue for statistical categories to measure ethnic or racial populations as part of an effort to fight against discrimination, and those who argue against such statistics. The latter, including the authors of the present article, discuss the impossibility of building such categories, their inadequacies, and the political and social consequences they could have because of the way they represent society. They also argue that there are better, more efficient ways to measure discrimination and to fight against it. After describing the history of this debate, the authors present the different positions and explore the larger implications of the debate for French public life.