As the common argument goes, Columbus’ journey across the Atlantic Ocean in 1492 was a bold move in clear challenge to those who believed that the Earth was flat, so he proved for once and all that the theory was wrong. In other words, the discovery of America did not only introduce the modern world in geographic terms, it also represented a fundamental paradigm shift away from a religious, dogmatic, explanation of man’s physical environment toward trustworthy, verifiable, empirical sciences. Washington Irving, in his 1828 biography of this famous discoverer, presented a most impressive scene of Columbus facing the Council of Salamanca (1487) and arguing for the validity of his conclusions that it would be possible to sail all the way west to reach China. Irving comments on the situation of geographical in the Middle Ages and paints a bleak picture, condemning medieval sciences as incompetent and ignorant because of the strong belief in the absolute validity of the Biblical words over practical experience. […]
Irving delights in making fun of the learned Spanish scholars who represented the Middle Ages in its darkest form, trusting the theological authorities more than the experimental sciences. He has one scholar, in particular, step forward who “cited from Lactantius to confuse Columbus”. […]
Unfortunately, Irving was fantasizing here, not about Columbus’s meeting with this powerful council in Salamanca, but about their assumption that the earth was flat. The Spanish savants fully understood the problems that Columbus would face if he were to sail west, arguing, rightly so, that the entire expedition would fail since the ships could not take enough food and water with them for the long journey. They could also not imagine that there would be any inhabitable land beyond the reach of the known world. Moreover, they rather trusted the Biblical account, not to forget its countless interpretations and the learned treatises of the Church Fathers, with regard to the nature of the unknown than they would trust this simple mariner and his hypotheses. But there were no arguments pertaining to the shape of the Earth, only arguments pertaining to the actual size of the globe!
In mathematical terms, as we know today, Columbus did not only miscalculate the actual distance between the Canaries – from where he planned to set sails – to Japan, namely 4,450 km instead of the actual 22,000, he also manipulated the figures available to him by previous geographers and scientists. In Jeffrey Burton Russell’s words, “If God or good luck had not put America – the West Indies – in the way to catch him, Columbus and his crew might have indeed have perished, not from falling off the earth but from starvation and thirst. Columbus clinched his argument to his patrons by adding that the voyage could probably be broken at intervening islands. Already Pierre d’Ailly (1350-1420) had specifically pointed out the spherical nature of the Earth, and so had John Burridan (ca. 1300-58), Nicholas Oresme (ca. 1320-82), Giles of Rome (1247-1316), and Roger Bacon (ca. 1220-92). Certainly, there were always some theologians, such as the African Lactantius (CE 245-325) and the sixth-century Eastern Greek Christian, Cosmas Indicopleustes, who believed the opposite. But just as determined individuals and even major church groups today firmly believe that Darwin’s Theory of Evolution has to be rejected outright in favor of the notion of Intelligent Design, some people in the Middle Ages stubbornly refused to abandon their conviction of the Earth being a flat disk.
Albrecht Classen, The Medieval Chastity Belt: A Myth-Making Process (2007)