Myth: That Before Columbus, Geographers and Other Educated People Thought the Earth Was Flat

A falling apple inspired Isaac Newton’s insight into the law of gravity — or so the story goes. Is it true? Perhaps not. But the more intriguing question is why such stories endure as explanations of how science happens. Newton’s Apple and Other Myths about Science brushes away popular misconceptions to provide a clearer picture of great scientific breakthroughs from ancient times to the present. Edited by Ronald Numbers and Kostas Kampourakis, the book debunks the widespread belief that science advances when individual geniuses experience “Eureka!” moments and suddenly comprehend what those around them could never imagine. Science has always been a cooperative enterprise of dedicated, fallible human beings, for whom context, collaboration, and sheer good luck are the essential elements of discovery. Here is a brief excerpt from Lesley B. Cormac’s chapter looking at whether people in the Middle Ages really thought the world was flat.

One of the most enduring myths that children grow up with is the idea that Columbus was the only one of his time who believed that the Earth was round; everyone else believed it was flat. “How brave the sailors of 1492 must have been,” you might imagine, “to travel towards the edge of the world without fear of falling off!”
— Ethan Siegel, “Who Discovered the Earth Is Round?” (2011)

On the February 15, 2014 Sunday morning program CBS News Sunday Morning, [Charles] Osgood touted a recent speech by Secretary of State John Kerry in which Kerry “likened deniers of climate change to those who once believed the Earth is flat.”
— Gary DeMar, “Why John Kerry’s Flat Earth Society Slam Is All Wrong” (2014)

Did people in the Middle Ages think that the world was flat? Certainly a quick Google search of the Internet might convince us that this might have been so. Although dozens of Internet sites will tell you that this is a myth to be debunked, the very fact that so many Internet pundits continue to do so tells us just how enduring a misconception this is. The claim that it was once common knowledge that the world was flat is now even a political metaphor for science deniers. As the story goes, people living in the Dark Ages were so ignorant (or so deceived by Catholic priests) that they believed the earth was flat. For a thousand years they lingered in ignorant obscurity, and were it not for the heroic bravery of Christopher Columbus (1451–1506) and other explorers, they might well have continued in this ignorance for even longer. Thus, it was the innovation and courage of investors and explorers, motivated by economic goals and modern curiosity, that finally allowed us to break free from the shackles forged by the medieval Catholic Church.

Where does this story come from? In the nineteenth century, scholars interested in promoting a new scientific and rational view of the world claimed that ancient Greeks and Romans had understood that the world was round, but that medieval churchmen had suppressed this knowledge. Pro-Catholic scholars responded by making the argument that most medieval thinkers readily acknowledged that the world was round. Critics, however, dismissed such opinions as mere apologetics. Why did the battle rage over this particular issue? Because a belief in the flat earth was equated with willful ignorance, while an understanding of the spherical earth was seen as a measure of modernity; the side one defended became a means of condemning or praising medieval churchmen. For natural theologians such as William Whewell (1794–1866) or rationalists such as John Draper (1811–1882), therefore, Catholicism was bad (since it promoted a flat-earth view), while for Roman Catholics, Catholicism was good (since it promoted modernity). As we’ll see, neither of these extremes describes the true state of affairs.

This equation of rotundity with modernity also explains why nineteenth-century American historians claimed that it was Columbus and the early mercantilists who proved that the earth was round and thereby ushered in modernity — and America. In fact, it was a biography of Columbus by the American author Washington Irving (1783–1859), the creator of “Rip Van Winkle,” that popularized this idea to the world. Although Irving listed a number of arguments made by Columbus, it was his alleged proof of the round earth that struck his audience most forcefully. This equation of a spherical earth with modern scientific thinking also explains why contemporary politicians might want to compare flat-earth thinking with other irrational beliefs, such as denying climate change.

But the reality is more complex than either of these stories. Very few people throughout the Middle Ages believed that the world was flat. Thinkers on both sides of the question were Christians (Roman Catholic or Eastern Orthodox), and for them, the shape of the earth did not equate with progressive or traditionalist views. It is true that most clerics were more concerned with salvation than the shape of the earth — that was their job, after all. But God’s works in nature were important to them as well. Columbus could not have proved that the world was round because this fact was already known. Nor was he a rebellious modern; rather, he was a good Catholic who undertook his voyage believing he was doing God’s work. A transformation was taking place in fifteenth-century views of the earth, but it had more to do with a new way of mapping than with a move from flat earth to sphere.

Scholars in antiquity developed a very clear spherical model of the earth and the heavens. Every major Greek geographical thinker, including Aristotle (384–322 bce), Aristarchus of Samos (310–230 bce), Eratosthenes (273–ca.192 bce), and Claudius Ptolemy (ca. 90–ca.168), based his geographical and astronomical work on the theory that the earth was a sphere. Likewise, all of the major Roman commentators — including Pliny the Elder (23–79), Pomponius Mela (first century), and Macrobius (fourth century) — agreed that the earth must be round. Their conclusions were in part philosophical — a spherical universe required a sphere in the middle — but were also based on mathematical and astronomical reasoning. Most famous was Aristotle’s proof of the sphericity of the earth, an argument used by many thinkers in the Middle Ages and the Renaissance.

If we examine the work of even early-medieval writers, particularly in Europe, we find that with few exceptions they held a spherical-earth theory. Among the early church fathers, Augustine (354–430), Jerome (d. 420), and Ambrose (d. 420) all agreed that the earth was a sphere. Only Lactantius (early fourth century) provided a dissenting opinion, but he rejected all pagan learning because it distracted people from their real work of achieving salvation.

From the seventh to the fourteenth century, every important medieval thinker concerned about the natural world stated more or less explicitly that the world was a globe, and many of them incorporated Ptolemy’s astronomy and Aristotle’s physics into their work. Thomas Aquinas (1225–1274), for example, followed Aristotle’s proof in demonstrating that the changing positions of the constellations as one moved about on the earth’s surface indicated the spherical shape of the earth. Roger Bacon (ca. 1214/ 1220–ca. 1294), in his Opus Maius (ca. 1270), stated that the world was round, that the southern antipodes were inhabited, and that the sun’s passage along the line of the ecliptic affected the climates of different parts of the world. Albertus Magnus (d. 1280) agreed with Bacon’s findings, while Michael Scot (1175–1234) “compared the earth, surrounded by water, to the yolk of an egg and the spheres of the universe to the layers of an onion.” Perhaps the most influential geographers were Jean de Sacrobosco (1195–1256), whose De Sphera (ca. 1230) demonstrated that the earth was a globe, and Pierre d’Ailly (1350– 1410), Archbishop of Cambrai, whose Imago Mundi (written in 1410) discussed the sphericity of the earth.8 Both of these books enjoyed great popularity; Sacrobosco’s was used as a basic textbook throughout the Middle Ages, while d’Ailly’s was read by early explorers, such as Columbus.

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Given this background, it would be silly to argue that Columbus proved the world was round — or even argued so. However, popular accounts continue to circulate the erroneous story that Columbus fought the prejudiced and ignorant scholars and clerics at Salamanca, the home of Spain’s leading university, before convincing Queen Isabella (1451–1504) to let him try to prove his position. The group of scholars informally assembled to advise the king and queen of Spain greeted Columbus’s proposal — that the distance from Spain west to China was not prohibitively great and that it was shorter and safer than going around Africa — with incredulity. Since no records remain of that meeting, we must rely on secondhand reports written by Columbus’s son Fernando (1488–1539) and by Bartolemé de las Casas (1484–1566), a Spanish priest who wrote a history of the New World. Both tell us that the learned men at Salamanca were aware of the current debates about the size of the earth, the likelihood of inhabitants in other parts of the world, and the possibility of sailing through the torrid zone at the equator. They challenged Columbus on his claim to having knowledge superior to that of the ancients and on his ability to do what he proposed. Rather than denying that the earth was spherical, they used its sphericity in their arguments against Columbus, arguing that the round earth was larger than Columbus claimed and that his circumnavigation would take too long to complete.

When Peter Martyr (1457–1526) praised the achievements of Columbus in his laudatory preface to Decades of the New World (1511), he was quick to point out that Columbus had proven the equator was passable and that there were indeed peoples and lands in those parts of the globe once thought to have been covered with water. Nowhere, however, did he mention proving the sphericity of the earth. If Columbus had indeed proved the point to doubting scholars, Peter Martyr would surely have mentioned it.

Those who want to preserve Columbus as an icon for the historic moment when the world became round might appeal to the common people. After all, weren’t Columbus’s sailors afraid of falling off the end of the earth? No, they weren’t. According to Columbus’s diary, the sailors had two specific complaints. First, they expressed concern that the voyage was taking longer than Columbus had promised. Second, they were worried that because the wind seemed to be blowing consistently due west, they would be unable to make the return voyage eastward.

As we have seen, there is virtually no historical evidence to support the myth of a medieval flat earth. Christian clerics neither suppressed the truth nor stifled debate on this subject. A good son of the church who believed his work was revealing God’s plan, Columbus didn’t prove that the earth was round — he stumbled on a continent that happened to be in his way.