Readers of the Mémoires of the Académie royale des Insciptions et Belles-Lettres for 1761 must have been surprised to read that “Chinese vessels made the voyage to America many centuries before Christopher Columbus.” The academician Joseph Deguignes of the Bibliothèque du Roi had concluded from his wide reading of Chinese historical and geographical works that the mythical land of “Fou-sang,” or Fusang 扶桑, could be nothing other than the Northwest coast of North America, only recently charted by French and Russian navigators. Based on the account in the seventh-century History of the Southern Dynasties 南史, Deguignes reported that while Europe lay in the darkest thralls of the middle ages, Chinese merchants and missionaries were carrying on an active commerce with Native American peoples. Monks had brought Buddhism to the New World, where the weather was mild, food and game abounded, and the Fusang tree provided for daily needs. The inhabitants were highly civilized: they knew the secrets of the wheel and they manufactured silk and paper, they had complex marriage laws and a penitentiary system. Adding narrative color and scientific legitimacy to Deguignes's account, the cartographer Philippe Buache drew an original map on which he charted the epic medieval Chinese journey to the coasts of North America.

The Enlightenment story of Fusang shows how French thinkers put Chinese geography to work and why they thought it mattered. Deguignes's report was taken up for consideration by the leading French geographers of his day, including Buache, Joseph-Nicolas Delisle, and Jean-Baptiste Bourguignon d'Anville. They debated the value of Chinese geography, from the cosmography of the Classic of Mountains and Seas 山海經 to the mathematical surveying techniques in the Classic of Documents 書經. Conclusions drawn from the Chinese tradition were put to work in European theories on the local geography of the Pacific Rim, the organization of the continents, and the propagation of societies. At stake was nothing less than the universal progress of natural philosophy, which the story of Fusang was understood both to narrate in its spread around the world and to exemplify in contributing to geographical knowledge. In France, Fusang thus took on new meaning, informing an Enlightenment theory of the development of human civilization in time and space that the medieval Chinese monks who supposedly reported it could never have imagined.