Tag: Columbus

Yet Another Flat Earther

In a footnote to a previous post I worried that in a post on Columbus and the flat earth myth Valerie Strauss had preferred the opinions of a mathematician over the expertise of a historian. And in fact, Strauss did prefer the dilettante to the expert. She rejected the historian’s conclusions, which were based in training, evidence, and experience, and relied instead on the opinions of a non-expert, which ignored both evidence and experts.

Perhaps because she is awed by mathematics or assumes scientists are smarter than everybody else, Strauss aped the mathematician Robert Osserman’s fantasy about people in the early middle ages believing in a flat earth. Osserman was an accomplished mathematician at Stanford. He was also celebrated for bringing “math to a broad audience.” Turns out, he also happens to have been a flat earther.

Rober Osserman’s Poetry of the Universe

For reasons that make little sense, Osserman repeats a particular version of the flat earth myth in his Poetry of the Universe. Chapter 2, “Encompassing the Earth,” opens with a rejection of the idea that Columbus proved the earth was round. Osserman even calls out this myth, saying

One of the enduring myths of the Western world is that in order to gain support for his expeditions, Christopher Columbus had to first overcome a pervasive belief that the earth was flat rather than round …

So far, so good. But then Osserman succumbs to the fantasy,

The myth undoubtedly stems in part from a compression of the historical past, conflating the early Middle Ages, when a belief in a flat earth was indeed widespread in Europe, with the late Middle Ages…

Osserman too traffics in the flat earth myth.

No, the myth doesn’t stem from a “compression of the historical past” but rather a willful rejection of the historical past, a willful rejection of historical fact, a willful rejection of evidence, and a profound intellectual laziness validated by arrogance and hubris. I am confident that Osserman had multiple colleagues at Stanford who could have explained to him how his beliefs were wrong, were myths. All he had to do was dial an extension or walk across campus and ask them. But he chose not to. He chose, instead, to traffic in a myth, to spread misinformation, and to do so with the authority of being a “mathematician.”

That authority was persuasive. It dazzled Strauss and convinced her to reject the expertise of the historian in favor of the unfounded beliefs of the mathematician. Her preference for the mathematician has, in turn, disseminated the myth yet further, now robed in the authority of a Washington Post column that claims to be grounded in research and to be a resource for teachers and parents. Unfortunately, Strauss has mislead the teachers, parents “(and everyone else)” who reads her column.

Another Flat Earther

I marvel at the power of that old chestnut about people in the middle ages believing the earth was flat. Even a person who rejects the myth that Columbus proved the earth was a sphere nevertheless trots out the poor, benighted medieval Europeans as believers in a flat earth. Consider, for example, Valerie Strauss’s post for the Washington Post: “Busting a myth about Columbus and a flat Earth.” Despite the promising title, she traffics in one of the typical versions of the flat earth myth.

Strauss celebrates scholars in antiquity who knew the earth was a spherical. Aristotle, Euclid, Ptolemy, these people got it right. Medieval Europeans, however, were apparently not so bright. On the basis of no evidence, she claims:

During the early Middle Ages,[1] it is true that many Europeans succumbed to rumor and started believing that they lived on a flat Earth.

In her story, medieval Europeans were back on the right track by the 1200s CE, when texts like Sacrobosco’s De sphaera “discussed the Earth’s shape.”

Strauss has no excuse for making this claim. She is simply and demonstrably wrong. And she should know it.

Strauss cites Jeffrey Burton Russell’s book, Inventing the Flat Earth, implying that she has read it. If she has, she can’t also believe that people in the early middle ages thought the earth was flat. If she has read even the first 30 or so pages of Russell’s book, she will recognize her version of this myth as one of the most common. Russell spends some time surveying this form of the flat earth myth:

Another version of the Error is that the ancient Greeks may have known that the world was round, but the knowledge was lost (or suppressed) in medieval darkness.… Many inconsistent varieties of this version exist: The knowledge was lost in the first century A.D., or the second, or the fifth, or the sixth, or the seventh; and on the other end it was lost until the fifteenth century, or the twelfth, or the eighth. The mildest variety, therefore, posits only a few years of darkness from the flattening of the Greek earth to the rounding of the modern one.[2]

Yet Strauss seems as committed as ever to a Dark Ages model of history, complete with its flat earth fantasy.[3]

Orlando Ferguson’s amazing map of a flat earth, from 1893.

Two further thoughts:

First, I am particularly worried because Strauss’s myth-busting post appeared on her regular column, “The Answer Sheet,” which she characterizes as a “A school survival guide for parents (and everyone else).” How many parents and everyone else’s have read and been misinformed by Strauss’s “survival guide?” At least one other person has read, believed, and repeated Strauss’s claim about medieval Europeans thinking the earth was flat.

On April 15 the anonymous blog, “Today in History,” posted “Columbus’s Flat Earth.”[4] Borrowing closely from Strauss, the author asserts:

Since Columbus owned a copy of an ancient Greek book [i.e., Ptolemy’s Geography] that outlined the reasons why the earth must be round, he did not believe that the earth was flat. So did anyone ever believe that the earth was flat? Actually, yes. During the Middle Ages in Europe, many people began to believe the rumors that the earth was actually flat.

Actually, no. During the Middle Ages in Europe, almost nobody began to believe or likely even heard any rumors that the earth was actually flat. The person who runs “Today in History” claims to be “someone who love history” and is “passionate about learning” and hopes to “provide more insight into event in the past.” Alas, duped by Strauss’s “survival guide” the person who runs “Today in History” is passing on misinformation and falsehoods.

Second, I also worry that Strauss believes expertise in mathematics is somehow a) applicable to other, non-scientific domains of knowledge and b) superior to historical expertise. Why else would she gratuitously cite a mathematician for evidence that “Columbus did not worry that he would fall off the Earth’s edge.”

On the one hand, Strauss’s post reflects willful ignorance and dogmatic rejection of evidence. On the other hand, Strauss’s post reflects historians’ failure to dispel this myth. Despite all our ranting and raving, we historians have failed to communicate with audiences, e.g., scientists, journalists and authors, politicians, educators, etc. I have fared no better in various efforts to combat this myth (some of which you can find by searching this blog for flat earth).

I am going to give it another go next week, at Taste of Science Philadelphia, where I am speaking along with climate scientists at “Climate change: How we got here, and looking to the future.” Maybe lubricated with some beer and good food I’ll have better luck.


  1. I can only guess that Strauss means by “early Middle Ages” some portion of the millennium between Ptolemy and Sacrobosco.  ↩

  2. J.B. Russell, Inventing the Flat Earth (1991), 28–29.  ↩

  3. Perhaps the other book Strauss cites, R. Osserman, Poetry of the Universe makes this asinine claim. I haven’t had a chance to look at it. If it does, and if she preferred to accept the comments of a mathematician over those of a historian, i.e., to accept the opinion of a non-expert over the knowledge of an expert, we have other problems.  ↩

  4. The “Columbus’s Flat Earth” post linked to my “Washington Irving’s Columbus and the Flat Earth,” which led me to Strauss’s post and, in turn, prompted this current post. ↩

Washington Irving’s Columbus and the Flat Earth

For generations now American school children have learned that Christopher Columbus proved the earth was round. They have learned that the Church tried to prevent Columbus from sailing west to Asia, fearing that he and his seamen would sail off the edge of the earth or plunge into a chasm. They know that Columbus persevered and eventually overcame religious opposition. And they know that Columbus was right. At its core, the Columbus story pits humble rationality against dogmatic obscurantism in a sort of secular inversion of the David and Goliath story. Judging from the students in my intro classes, the Columbus story is thriving in American schools.

The only problem, as any historian or historian of science will tell you: it’s a myth.

Like any beloved myth, the Columbus story mixes truths and truthiness, something that seems so natural and so obviously true but isn’t. Columbus did face opposition. He did persevere. He did sail west. He did find land (not Asia as he had predicted and continued to believe but the New World). But these truths have nothing to do with the shape of the earth—Columbus and all his detractors knew that the earth was round. The truthiness in the myth lies, on the one hand, in the image of a dogmatic medieval Spanish Church that clung to a retrograde idea about the shape of the earth and refused to listen to reason and evidence. On the other hand, truthiness also inheres in the image of Columbus as a proto-modern, quasi-secular thinker guided only by reason and evidence. The truthiness is the reason 19th-century authors fabricated the myth and 21st-century educators continue to repeat it.

The seeds of the Columbus myth seem to grow from Washington Irving’s biography of Columbus, A History of the Life and Voyages of Christopher Columbus (1828) (online here). Alexander Everett, Minister Plenipotentiary to Spain, had invited Irving to Madrid in the hopes that Irving would translate a recently published collection of documents on Columbus. When Irving got there and had a chance to read the collection, he decided

that a history, faithfully digested from these various materials, was a desideratum in literature, and would be a more acceptable work to my country, than the translation [he] had contemplated.

So he set out to write a history of Columbus. Irving enjoyed unfettered access to libraries, which he mined for his biography. He culled from manuscripts and published books a wealth of information. Despite the material at his disposal, the sources were at times silent or missing or not all that interesting. So Irving embellished. He wrote what should have happened, what surely did happen even if the evidence had since disappeared. He did what historians had been doing since Herodotus: he made it up. He seamlessly wove fact and fiction together into a “clear and continued narrative.”

Irving detailed Columbus’s thoughts about the size of the earth. Columbus examined earlier maps that depicted the known world that stretched from Canary Islands in the west to its eastern limits in China. The Portuguese had more recently explored further west to the Azores. According to Columbus’s calculations, only a third of the earth’s circumference remained unexplored. Moreover, based on his reading of Arabic astronomers, Columbus thought the length of a degree at the equator was shorter than the commonly accepted length. The third of earth’s circumference was, Columbus concluded, much smaller than that accepted by contemporary cosmographers. As Irving pointed out in various places, Columbus was aberrant in his beliefs, which beliefs were, in fact, wrong:

It is singular how much the success of this great undertaking depended upon two happy errors, the imaginary extent of Asia to the east, and the supposed smallness of the earth ….[1]

But a recitation of historical truths was boring, especially when Irving knew the confrontation between Columbus and the Council at Salamanca must have been dramatic. So Irving embellished a little when he described Columbus before the council. He enhanced the historical truths with truthiness—events that seemed so right, so natural, that must have happened even if there’s no record of them.

The Council at Salamanca was composed of professors of astronomy, geography, mathematics, as well as church dignitaries and learned friars, and convened to examine Columbus’s “new theory.” Most of the council members were biased against Columbus, “an obscure foreigner, without fortune, or connexions, or any academic honors.” In what must have been the acme of truthiness for Irving, he described the council benighted by “monastic bigotry” and assailing Columbus with Biblical citations. They rejected mathematical demonstrations that conflicted with scriptures or Church Fathers. At issue was not, however, the shape of the earth, but the possibility of antipodes:

Thus the possibility of antipodes in the southern hemisphere … became a stumbling block with some of the sages of Salamanca.

Members of the council invoked Lactantius, who connected the existence of antipodes to the shape of the earth. Irving quoted what has become the standard passage:

“The idea of the roundness of the earth,” he adds, “was the cause of inventing this fable of the antipodes with their heels in the air….”

A quick reading of Irving might confirm that the issue here was the shape of the earth, but in the next sentence he returned to the antipodes:

But more grave objections were advanced on the authority of St. Augustine. He pronounced the doctrine of antipodes incompatible with the historical foundations of our faith; since, to assert that there were inhabited lands on the opposite side of the globe, would be to maintain that there were nations not descended from Adam, it being impossible for them to have passed the intervening ocean.

The council’s grave objections focused on the existence of other humans, not on the shape of the earth.

Iriving described briefly a couple objections raised about the shape of the earth—passages from the Psalms and St. Paul’s Epistle to the Hebrews—but these serve merely as a foil for the objections raised by “[o]thers, more versed in science, [who] admitted the globular form of the earth.” Their objections were grounded the knowledge that the earth was a sphere. They worried that it was impossible to sail across the torrid zone at the equator, that only the northern hemisphere was inhabitable, and that the circumference of the earth was so great as to require three years to sail across the Atlantic.

Whatever liberties Irving took in crafting his biography, he did not lose sight of historical truths. Instead, and perhaps more disturbingly, he enlisted those truths in the service of truthiness. In Irving’s version, Columbus had struggled against “errors and prejudices, the mingled ignorance and erudition, and the pedantic bigotry” of the Spanish Church that refused to listen to reason and evidence. His biography was less about Columbus and more about the timeless struggle between on the one hand rationality, science, individuality, and anti-aristocratic modernity and, on the other hand, a retrograde, oppressive, medieval Church. It was the story’s truthiness that appealed to other 19th-century authors.

Within a decade, William Whewell had published his History of the Inductive Sciences (1837) (online here). In a section on antipodes, he admitted that most people throughout history had known the earth was round. Only a few people who preferred scriptural evidence over physical evidence denied the sphericity of the earth. Lactantius, of course, and now Cosmas Indicopleustes, who says nothing about antipodes but offers an easily mocked tabernacle-shaped world and flat earth. Whewell then returns to the antipodes before concluding the section by casually remarking: “Tostatus notes the opinion of the rotundity of the earth as an unsafe doctrine, only a few years before Columbus visited the other hemisphere.” Again, Columbus and the shape of the earth.

By the latter 19th-century, the supposed truth of the Columbus story had completely replaced the historical truths. In works like John Draper’s History of the Conflict between Religion and Science (1874) (online here) we read nothing of the reasoned objections raised by the Council at Salamanca or of Columbus’s errors. Instead we learn that his proposal’s

irreligious tendency was pointed out by the Spanish ecclesiastics, and condemned by the Council of Salamanca; its orthodoxy was confuted from the Pentateuch, the Psalms, the Prophecies, the Gospels, the Epistles, and the writings of the Fathers—St. Chrysostom, St. Augustine, St. Jerome, St. Gregory, St. Basil, St Ambrose.

In the end, Columbus prevailed and along with Vasco Da Gama and Ferdinand Magellan finally settled the question of the shape of the earth.

By the time Andrew White wrote his A History of the Warfare of Science with Theology in Christendom (1896) (online here), Columbus’s struggles to overcome a medieval Church that believed in a flat earth had become historical fact. Historical truth had surrendered to truthiness. White transformed Irving’s biased but still recognizable historical account into little more than agitprop:

The warfare of Columbus the world knows well: how the Bishop of Ceuta worsted him in Portugal; how sundry wise men of Spain confronted him with the usual quotations from the Psalms, from St. Paul, and from St. Augustine; how, even after he was triumphant, and after his voyage had greatly strengthened the theory of the earth’s sphericity, with which the theory of the antipodes was so closely connected, the Church by its highest authority solemnly stumbled and persisted in going astray.

Despite decades of historical work and dozens of articles and textbooks and, more recently, blogposts, the Columbus myth is alive and well in the United States. The cosmologist Lawrence Krauss recently invoked it. President Obama equated opponents of clean energy to people who opposed Columbus on the grounds that the earth was flat. The president received much applause when he said (at 0:55 in the video):

If some of these folks [opponents of clean energy] were around when Columbus set sail, they must have been founding members of the flat earth society. They would not have believed that the world was round.

More recently still, Chris Impey, an astronomer at University of Arizona who claims to be interested in and knowledgable about history, fell prey to the Columbus myth in a lecture posted on YouTube, “Ancient Astronomy.” He identifies himself as “a student of history” and a member of a select group, “the educated extreme of the culture.” Yet moments earlier he lamented that

[t]here was a thing called the Dark Ages. There was a period of 700 or 800 years when all of the extraordinary insights of the Greek philosophers were utterly lost. People thought the world was flat. And truly thought the world was flat. There were demons that lurked at the edge of the map.

He underscores this claim in his video series “Teach Astronomy” (which is part of an online textbook). In the section on “The Dark Ages” he says:

In the fourth century with the fall of Rome and the sacking of the great library at Alexandria scientific darkness fell across Europe. Even the language of learning, Latin, splintered as warring tribes took over. The theology of the day was defined by Augustine, and the Christian church was mostly anti-science. The learning of the Romans and the Greeks was denigrated as pagan knowledge. Even the knowledge of the round Earth was lost for many centuries.

Impey’s comments reveal, I think, the power of the Columbus myth. It has become so central to the idea of modernity, that even a self-described student of history who is both smart and very educated—part of the “educated extreme”—is not motivated to do a simple internet search to fact check that part of his lecture and textbook. Whereas Irving had mixed truths and truthiness into a “clear and continued narrative,” subsequent authors have pruned the historical truths from the story, leaving just a myth that has become part of modern folklore.


  1. Irving’s biography also depicts Columbus as something of a zealot, motivated by religious and dogmatic convictions as much as anything. For more on Columbus’s religious motivations, see Columbus’s Voyage was a Religious Journey.  ↩

Cosmas, the Tabernacle, and the Flat Earth

The Flat Earth Myth remains a compelling story despite continued efforts by historians to debunk it (I’ve discussed it before). Typically, it combines two fables: first, people in the middle ages believed that the earth was flat; second, Columbus proved that the earth was round. Washington Irving’s popular biography of Columbus, A History of the Life and Voyages of Christopher Columbus (1828) made the Columbus part of the story fashionable, while Andrew Dickson White’s History of the Warfare of Science with Theology in Christendom (1896) cemented in our collective consciousness the part about medieval people.

Occasionally we do find a person in the middle ages who argued for a flat earth. One such example is Cosmas Indicopluestes, a sixth-century Byzantine traveller-turned-monk. In his The Christian Topography he attacked pagan ideas about the sphericity of the earth and the universe. In book II, “The Christian theories regarding the form and position of the whole world, the proofs of which are taken from Divine Scripture” (and again later in book IV), he raised what he thought were various philosophical and empirical difficulties for a spherical earth resting at the center of the spherical universe, e.g.,

  • What would keep the earth steady and fixed at the center?
  • Why, if the fixed stars are all equa-distant from the earth, as they must be if the earth is at the center of the vault of the fixed stars, do the stars appear different sizes, and vary in brightness color?
  • Why do some stars seem brighter and therefore closer than some planets (he uses the example of Mars)?
  • Why do the planets progress through the zodiac at some times and move backwards at other times?
  • How can epicycles be real if the heavens are made up a perfect fifth element eternally in circular motion?

His empirical and philosophical objections are not particularly persuasive. But what makes Cosmas’s argument especially suspect to modern eyes is his unabashed reliance on scripture. He did not disguise the fact that his goal was to use scripture to refute the fictions and fables of Greeks, by which he means pagan Greek philosophers. Cosmas did not help his cause or the reputation of Byzantine scholars in general, at least in our eyes, when he argued that the earth was shaped like a parallelogram, surrounded on all four sides by oceans.

Cosmas’s model of the earth, taken from the 19th-c. edition printed by the Hakluyt Society.
Cosmas’s model of the earth, taken from the 19th-c. edition printed by the Hakluyt Society.

Cosmas placed this parallelogram inside a tabernacle, which reflected the shape of the cosmos. According to Cosmas’ reading, Moses was divinely inspired to construct the tabernacle because it mirrored the shape of the cosmos.

Cosmas’s tabernacle-shaped cosmos, taken from the 19-c. edition printed by the Hakluyt Society.
Cosmas’s tabernacle-shaped cosmos, taken from the 19-c. edition printed by the Hakluyt Society.

Cosmas became the poster child for the deluded premodern world filled with people who believed the earth was flat. Andrew Dickson White surveyed Cosmas’ ideas and ridiculed him for being deluded.

In the sixth century this development culminated in what was nothing less than a complete and detailed system of the universe, claiming to be based upon Scripture, its author being the Egyptian monk Cosmas Indicopleustes. Egypt was a great treasure-house of theologic thought to various religions of antiquity, and Cosmas appears to have urged upon the early Church this Egyptian idea of the construction of the world, just as another Egyptian ecclesiastic, Athanasius, urged upon the Church the Egyptian idea of a triune deity ruling the world. According to Cosmas, the earth is a parallelogram, flat, and surrounded by four seas. It is four hundred days’ journey long and two hundred broad. At the outer edges of these four seas arise massive walls closing in the whole structure and supporting the firmament or vault of the heavens, whose edges are cemented to the walls. These walls inclose the earth and all the heavenly bodies.…
Nothing can be more touching in its simplicity than Cosmas’s summing up of his great argument, He declares, “We say therefore with Isaiah that the heaven embracing the universe is a vault, with Job that it is joined to the earth, and with Moses that the length of the earth is greater than its breadth.” The treatise closes with rapturous assertions that not only Moses and the prophets, but also angels and apostles, agree to the truth of his doctrine, and that at the last day God will condemn all who do not accept it.

White’s criticism benefits from the clarity of hindsight and the condescension that such clarity conveys. Cosmas’ theory was an easy target. But there is no evidence that he was the vanguard of a widespread movement. Instead, he seems to have recognized that his theory was peculiar. His goal in writing his The Christian Topography was to refute the more commonly held belief that the world and the heavens were spherical. Cosmas’ ideas do not appear to have gained much traction. We don’t see any real interest in them until the end of the 17th or the beginning of the 18th century, and then again in the 19th. David Lindberg dismisses Cosmas:

Cosmas was not particularly influential in Byzantium, but he is important for us because he has been commonly used to buttress the claim that all (or most) medieval people believed they lived on a flat earth. This claim…is totally false. Cosmas is, in fact, the only medieval European known to have defended a flat earth cosmology, whereas it is safe to assume that all educated Western Europeans (and almost one hundred percent of educated Byzantines), as well as sailors and travelers, believed in the earth’s sphericity.[1]

Unfortunately, the Flat Earth Myth and Columbus’s role in it remain alluring and incredibly common. No amount of historical scholarship by itself will dislodge them from our popular consciousness. We must first understand why we hold onto these myths, why they make us feel so comfortable, what work they do for us. Only then we will have a better idea of how to replace them.


  1. David Lindberg, The Beginnings of Western Science (Chicago, ), 161.  ↩

Fighting the Flat Earth Myth

YouTube that briefly looks at and explains five historical misconceptions: horned Viking helmets, Lady Godiva, the tiny Napoleon, the infamous vomitorium, and Columbus and the flat earth. See 5 Historical Misconceptions, which was linked to at Smithsonian.com. The Columbus bit is the last section and begins around 2:50 into the video. The video is a bit quirky but amusing and accessible. According to the stats, the video C.P.G. Grey posted a week ago has already attracted more than 454,000 views and 10,000 likes. It seems Grey has developed an effective means of reaching a broad audience.

Columbus (not) convincing the masses that the earth is round.

On C.G.P. Grey’s YouTube channel there are a few other videos that treat science and history of science topics, along with some explanations of political processes, coffee, and santa. While I would like to think there is some connection between my ranting about Columbus and the flat earth myth, that’s probably attributing to me too much credit. I am content to see that somebody else has joined the struggle.