Montesquieu is recognized as a theorist of diversity and pluralism. In this paper, we focus on the question of the diversity of manners, leaving aside the question of diversity of political and social powers, which have already been the subject of numerous analyses. We shall take Montesquieu's two major texts, his epistolary novel, Lettres persanes (1721), and his theoretical work, De l'esprit des lois (1748).