Abstract: Understanding why early modern Europeans transformed systematic cultural comparisons into an essential intellectual resource for their new, ‘modern’ narratives of world history is crucial to re-assessing the origins of the Enlightenment and its legacy. It also clarifies why the concepts of civilization and, eventually, culture, became central to the hierarchies underlying European self-understanding, replacing (but also subsuming) religious categories. This chapter offers a contextual reading of the early modern genealogy of ethnological comparatism, paying particular attention to various works produced between the 1550s and 1750s by authors such as Bartolomé de Las Casas, Alessandro Valignano, Athanasius Kircher, Hugo Grotius, François Bernier, La Créquinière, Jean-Frédéric Bernard and Lafitau. By doing so, it distinguishes three debates that clarify the logic underlying the interaction between ethnographic evidence, antiquarian erudition, and a variety of religious and philosophical concerns. The essay concludes by suggesting that the specific regime of comparatism that characterized the intellectual culture of the Enlightenment was defined by the connection between ethnological comparisons and a deep reconfiguration of ancient history, one that took non-European sources seriously.