From its Polybian origins, universal history was defined by its concern with the unity underlying the diversity of events. Polybius found this unity in the “exemplar theory of history,“ in the notion that history was philosophy teaching by examples, which Cicero immortalized in his commonplace, Historia magistra vitae. For all practical purposes, this commonplace remained unquestioned until the Early Modern period, when the spread of printing and advances in classical scholarship, among other factors, began to undermine the notion of universal lessons derived from contingent historical events. In his mid-sixteenth-century response to this challenge, Jean Bodin devised a method for systematizing the information contained in histories, but his attempt to bolster the exemplar theory of history only succeeded in highlighting the problem of finding unity amid diversity. Voltaire attempted to resolve this problem by redefining universal history as the history of civilization, as the story of “manners” and “mores,“ but he had difficulty integrating this account with history’s political narrative. His contemporary Montesquieu, however, successfully distilled from Cartesianism a new principle of unity that revealed each people as being characterized by its own distinctive nexus of politics and society, thus offering a firm foundation for the history of civilization.