In the first book of his history, Herodotus interrupts his political narrative to offer a quick ethnographic survey of the Persians, wherein he remarks that Persians respect other ethnicities in proportion to their proximity to Persia and reserve their greatest disdain for the most distant peoples. For Herodotus and his 5th-century Greek audience, the Persian himself incarnates the category of the Barbarian, whose inferiority is a function of his distance from Greece. This article proposes to assess the role of ethnocentrism, and its correlation of proximity and superiority, in two of the most iconoclastic figures in the history of Western thought, the ancient Greek sophist Antiphon of Rhamnus and the French Renaissance author Michel de Montaigne. Recently excavated and edited papyrus fragments reveal tantalizing glimpses of Antiphon’s lost treatise On truth, which seems to formulate a very far-reaching critique of ethnocentrism within the framework of cultural relativism. In his renowned essay Des Cannibales (“Of Cannibals”), Montaigne formulates a remarkably similar critique in his portrayal of the Brazilians encountered by Europeans in their trans-Atlantic voyages of the 16th century. Both authors take their distance from normative cultural values in order to rethink the relation of proximity and superiority, but Montaigne adds a temporal dimension to his analysis by challenging our condescension to the past. The vicinity of Montaigne and Antiphon suggests a similar intuition into the reversibility of cultural values and the contingency of collective identity in space and time.