Flat Earth? The Hidden Side of a Hoax

July 11, 2023
Source: District of the USA

No, the hoax in question doesn’t come from NASA. It refers to the stubborn yet false idea that the Middle Ages believed in a flat earth, and to the ideological underpinnings of this myth.

Captions, L-R:  The “Handsome God” of the cathedral in Reims (13th century), holding the globe in his hand  |  Salvator mundi by Willem Vrelant (†1481)  |  Nicolas Oresme in front of an armillary sphere with the Earth at the center. Illuminated illustration taken from his Treatise on the Sphere.  |  Diagram depicting men on Earth from the Imago Mundi by Gossuin de Metz (1246).  |  Diagram of a lunar eclipse in Treatise on the Sphere by Nicolas Oresme 

The recent coronation of Charles III presented us with an image that seemed to come straight out of a history book: the new King Charles III holding in his hands the insignia of royal power, including the orb and the cross, i.e. the sphere mounted with a cross that symbolizes the Earth redeemed by the cross of Jesus Christ. This orb has been in use for a very long time. You can find it throughout the Middle Ages, particularly in depictions of Christ holding the orb in his hand or beneath his feet. The orb represents a globe divided into three parts because of the three continents known at the time. One fact stands out right away: people depicted the Earth as a sphere well before the discovery of the Americas.

This should raise questions about an extremely widespread myth, namely, that “during the Middle Ages people thought that the Earth was flat.” You hear this said by journalists, intellectuals, public officials like Marlène Schiappa or Claude Allègre, and even in historical films, history books, and textbooks -- including recent ones. In a 2022 episode of “C Jamy” hosted by the celebrity Jamy Gourmaud, the guest speaker asserted: “In the 15th century, at the time of Christopher Columbus, many believed that the Earth was flat. They based this belief on what the Bible says, but Christopher Columbus didn’t believe this for a second.”1 And if we consult the barometer of public opinion today, namely ChatGPT, it tells us: “In the Middle Ages, people generally thought that the Earth was flat....Scientific theories about the shape of the Earth, like those developed by the ancient Greeks, were well-known, but they were often considered controversial or heretical by the Church.”2

Hence we see that the alleged “flat-earthism” of the medieval era is associated with the Catholic Church, which supposedly prescribed this naive idea as Biblically-based dogma in opposition to the wisdom of the pagan Greeks. Except that several decades of studies now have proven unequivocally that that is a myth. 3

Innumerable pieces of evidence

Besides the argument from iconography, it would suffice to open any scholarly book by a Catholic clergyman from this extensive period to put an end to the myth of medieval flat-earthism. We know that Christopher Columbus famously based his own audacious enterprise on an unfinished work by Pope Pius II (†1458), Historia rerum ubique gestarum, which the explorer had annotated. In the very first lines of this work, which was intended to be encyclopedic, Pius II asserts that “Almost everyone agrees that the shape of the world [= universe] is spherical [rotundam]4; they likewise agree about this concerning the Earth.” In the same work, the pope addresses the measurements of the earth’s circumference made by Eratosthenes (3rd century B.C.) and Ptolemy (2nd century B.C.). Christopher Columbus had also annotated the Imago mundi, a work by Cardinal Pierre D’Ailly (†1420). In it, the learned cardinal held forth on the radius and volume of the terrestrial sphere, climate zones according to latitude, and even the poles. For example, he states as a logical conclusion that “those who inhabited the Pole would have the sun above their horizon for half of the year and continuous night for the other half”5, which is remarkably accurate. Pierre d’Ailly was inspired by the Treatise on the Sphere by Nicolas Oresme (†1322), Bishop of Lisieux and advisor to Charles V. The title of this work is sufficiently evocative. The same Oresme was inspired by a work with the same title, The Treatise on the Sphere by the English monk Johannes de Sacrobosco († 1256), which was a major pedagogical success and was copied, expanded, and commented on for many centuries.

Around the same time, Saint Thomas Aquinas, who was trying to show in the very first pages of the Summa theologica that we can arrive at the same conclusion through different paths, illustrated his point as follows: “Thus, the astronomer and the physicist prove the same conclusion, namely, that the earth is round.”6 It was therefore a commonplace belief accepted by various scholars of the era. At the turn of the second millennium, Gerbert of Aurillac († 1003), who would be elected pope under the name Sylvester II, constructed a terrestrial globe and, like many learned men of that era, produced a commentary on Macrobius7 († 400), who declared the Earth to be spherical. We can also add Saint Bede the Venerable, († 735), who tells us that “the earth is like a globe;” Saint Isidore of Seville († 636), who talks about the “terrestrial globe” in his famous Etymologies; Boethius († 524) who mentions the “rounded mass of the Earth”8; Saint Gregory of Nyssa († 395), who describes an eclipse for us as a projection of the “spherical form”9 of the Earth upon the moon, etc10. Of course, ancient cosmology also posits an immobile Earth at the center of a finite spherical cosmos, but these errors were taken over from the Greeks. 

  • 1. Evan Adelinet, C Jamy of April 22, 2022. We find the same mistake made by Jamy Gourmaud in another episode of the show.
  • 2. 2. The response of ChatGPT to the question: “What was the shape of the Earth according to people from the Middle Ages?” It should be noted that if you ask the more specific question, “What do recent studies say about the idea that ‘people believed in a flat Earth during the Middle Ages’?”, you get a diametrically opposed answer that debunks the myth. This shows the AI was “trained” on contradictory data, the majority of which continues the myth. The first, much broader question generates the response that reflects the majority of texts, and therefore the dominant opinion. The second question aims to direct the response towards specific studies on this cliché.
  • 3. Cf. Inventing the Flat Earth, Jeffrey Burton Russel, 1991.
  • 4. The “world” isn’t the Earth, but rather refers to the ancient cosmology of a finite and spherical universe. The two terms are frequently confused, even in the works of historians. We are thoroughly committed to eradicating this equivocation throughout our article.
  • 5. Imago mundi by Pierre d’Ailly, translated and with commentary by Edmond Buron, vol. 1 (Maisonneuve frères, 1930).
  • 6. S.Th., I, q. 1, art. 1, ad. 2.
  • 7. Commentary on Cicero’s Dream of Scipio
  • 8. Consolation of Philosophy, II, 13.
  • 9. “According to the astronomers, in this world full of light, the shadow [on the Moon] is formed by the interposition of the body of the Earth. But the shadow, according to its spherical form, is confined to the rear part by the rays of the sun and takes the form of a cone. The sun, itself many times larger than the Earth, encircles it on all sides with its rays of light and, at the border of the cone, brings together the points of attachment of the light.” La Création de l’homme, Sources Chrétiennes, n° 6, ch. 21, p. 181
  • 10. Saint Ambrose asserts the sphericity of the “world,” and of the sun and the Moon as well, but it is difficult to find a precise mention of the Earth because that is not the kind of question that interests the Church Fathers. However, his cosmology strongly presupposes the sphericity of the Earth (cf. P. L. XIV, col. 133). The same is true of Eusebius of Caesarea (Collectio Nova Patrum et Scriptorum, ed. Montfaucon, t. 1, p. 460) or Saint Jerome (Commentary on the epistle to the Ephesians).

Captions, L-R:  Depiction of a solar eclipse from the Imago Mundi by Gossuin de Metz (1246)  |  Diagram of the Earth in the Ymago Mundi by Pierre d'Ailly (15th century). Notice the tropics of Cancer and Capricorn, as well as the Arctic and Antarctic circles  |  Map in T-O form, Isidore of Seville, Etymologies, 12th century, London, British Library, R12FIV, folio 135v. Only one hemisphere is represented. We find here the tripartite delineation of the three continents.  |  This modern diagram is supposed to depict the "Biblical cosmos." It does not depict the ancient understanding of the cosmos but rather depicts what some (incorrectly) believe about the ancients.  |  Currency featuring the effigy of Emperor Zeno († 491). The symbol of Victory is shown on the opposite side, holding an orb and a cross in her left hand.

The makings of a myth

One could assign very little importance to all of this. After all, the Christian can save his soul no matter what shape he attributes to the Earth. Isn’t the essential thing the frightening decline in life expectancy, which is now only 85 years, whereas in the Middle Ages there was hope for eternal life? Certainly—but what interests us here isn’t the shape of the Earth or the science of past eras, but the origin of a modern-day myth and what it tells us about our own age. For a long time, this myth has been used as a ready-made formula for ridiculing in one fell swoop the alleged stupidity of a Christian time period captured by the reductive title of the “Middle Ages.” The charge of “obscurantism,” however, can be turned back on the propagators of this myth, particularly because access to knowledge is incomparably better today than at a time when the printing press did not yet exist. It’s easy to debunk the myth of medieval flat-earthism, whereas it took a considerable amount of work during the Middle Ages to preserve the knowledge of the ancients. In an excellent book published in 2021 entitled La Terre plate, généalogie d’une idée faussse [The Flat Earth: Genealogy of a False Idea]11, two academics trace the origin of this stubborn myth. Is it surprising to find out that the principal author of the myth is none other than Voltaire? 

Lactantius and Cosmas

There are indeed several factors that helped give rise to this myth, in particular the Christian apologist Lactantius († 325), who is the sole outlier in the West in favor of a flat Earth. But nobody followed his opinion, and he was never numbered among the Church Fathers. In the East, we find one Cosmas Indicopleustes († approx. 550), who wrote a Christian Topography as a flat-earther. This illustrious unknown, whose very name is uncertain, seems to have been a Greek-speaking merchant who emerged during the Nestorian schism. The first Latin translation of his Topography dates back to 1707. Is it necessary to point out that he was therefore completely unknown to the medieval West? Yet Voltaire cites Lactantius and Cosmas as representing the position taken by all the Church Fathers: “The Fathers regarded the Earth as a massive ship surrounded by water; the prow was in the East, and the stern was in the West.”12

This is a failure to provide the basic historical context for evaluating the transmission of ideas. By lumping things together in this way, someone could just as easily claim that the third millennium adhered to flat earthism based on certain videos available online—it is treating a marginal thesis as if it were the norm. Even today, it is not uncommon to see Cosmas cited as the authority that he never was.

The question of the antipodes

In The City of God, Saint Augustine says that we shouldn’t believe those who assert the existence of “antipodeans”13—that is, people living on the opposite side of the Earth—because this theory is based on uncertain conjectures and not on convincing first-hand accounts. Here Saint Augustine simply points out an empirical demand that one could hardly blame him for and that has no bearing on the shape of the Earth. Yet Voltaire used this to conclude that the great Doctor of the Church denied the sphericity of the Earth! Likewise, Voltaire asserts that “Towards the end of the 15th century, Alonso Tostado, the Bishop of Avila, declares in his Commentary on Genesis that the Christian faith is rocked to its foundations if people believe in a round Earth.” Now, if anyone were to open the book in question, they would immediately discover that Voltaire is lying, since this bishop talks about the “spherical earth” and “our hemisphere”14. On the other hand, Tostado thinks, like Saint Augustine, that the antipodes are not inhabited. In his work cited above, Pierre d’Ailly describes the different theses on whether the antipodes are inhabited as “opinions.” In this domain, we’re very far afield of dogma. The exploration by Christopher Columbus gave an answer to this marginal question of the “antipodeans.” Only after the fact did the legend emerge of Christopher Columbus shattering flat earth dogma on the reef of experience, especially in a biography written by Washington Irving that greatly contributed to the myth. 

Is the Bible flat-earthist?

In the trial of flat-earthism, Voltaire calls the defendant Sacred Scripture to the witness stand. He writes with his characteristic ironic venom: “Proper respect for the Bible, which teaches us so many very necessary and very sublime truths, was the cause of this universal error among us. People had found in Psalm 103 that God stretched the heavens over the Earth like a tent.”15 Certainly, if you wanted to extract a confession of flat-earthism from the Bible, you can always pin this preconceived idea to a verse that agrees with it in one way or another16. However, the opposite is equally possible, since the Vulgate regularly designates the Earth with the word “orbis” that we could readily translate as “globe”17. But rather than engage in these fruitless debates, let us recall the well-known Catholic principle that Scripture must be read by the light of the Magisterium and the Church Fathers. Now, Voltaire is not a Father of the Church. Instead, let us give the floor to the remarkable wisdom of Saint Basil of Caesarea (†379) from his Homilies on the Hexaemeron, 9:

Some physicists who discussed the world talked extensively about the shape of the Earth; they investigated whether it is a sphere or a cylinder, whether it resembles a disc, and whether it is round on all sides or whether it has the shape of a fan and whether it is hollow in the center. For these are the ideas that the philosophers had, and with these ideas they have done battle one with the other18: for my part, I will not bring myself to despise our understanding of the world just because Moses, the servant of God, said nothing at all about the shape of the Earth and did not say that it has a circumference of 180,000 stadia19; because he didn’t measure the space of the air in which the Earth’s shadow extends when the sun has set; because he did not explain how this same shadow, when it approaches the moon, causes eclipses. Because he kept silent regarding these matters which, being useless for us, do not interest us, must I then denigrate the teachings of the Holy Spirit by comparing them to the foolish wisdom [of the world]? Or shouldn’t we rather glorify Him who, instead of entertaining our minds with vanities, wanted everything to be written for our edification and for the salvation of our souls? It seems to me that some, having failed to grasp this, have attempted to attribute a borrowed depth to the Scriptures through alterations of the meaning and figurative interpretations. But that means thinking oneself wiser than the prophets of the Holy Spirit and, under the guise of interpretation, introducing one’s own ideas into the text. Let us therefore accept these prophets exactly how they are written.

We find a similar remark by Augustine in Against Felix the Manichean regarding the movement of the stars:

The Gospels never put words like these in the mouth of the Lord: “I am sending you the Paraclete to teach you about the course of the moon and the sun.” Jesus Christ wanted to make Christians and not mathematicians. Regarding such matters, people need only the teachings given to them in the schools.”

Is the Church “round-earthist”?

The Church has not asserted the flatness of the Earth any more than its roundness because she asserts nothing on this subject. All of the Church Fathers, theologians, and popes who assert that the Earth is spherical do not base their thinking on the faith, because they consider it silent on this subject. Consistently, they refer to the “philosophers,” the “physicists,” and the “mathematicians.” They give arguments drawn from reason and observation: the shadow of the Earth on the moon during eclipses, the mast of the ship that disappears after the hull, or even the new stars that appear on the horizon during voyages at sea. This is an important point, because the myth tried to insinuate that faith and science were mutually exclusive. The believer supposedly was driven to look for truth in faith alone without leaving anything up to reason. But that is not thinking of the Church. The Fathers of the Church intended solely to reject the idea of the eternity of the world put forward by ancient cosmology. Modern cosmology cannot hold that against them.

The inertia of a hoax

All of these elements could lead the uninitiated astray, but they cannot impress any remotely serious historian. The first propagandists of the myth were the most culpable. But once the original hoaxes were uncritically accepted, those that followed repeated the Voltairian catechism, prompted by a blind faith in progress, so that with time, the hoax repeated thousands of times took on the character of an established historical truth. Michelet, who deserves the title of a novelist rather than a historian, obviously took up this fable, among many others. It was also perpetuated by Antoine-Jean Letronne, who held the chair of history at the prestigious College of France in the 19th century20. History has shown that even authors like Arthur Koestler have erred in this regard, even though he helped to demystify the Galileo affair21. There is even a book published in 2015 claiming to “shatter the myths” that presents a slightly nuanced version of it22. Initially, this myth was propagated mainly by anti-Catholic circles, but as time went on, it quickly came to deceive Catholics.

Additional elements were added later, such as old maps, sometimes presented as evidence of medieval flat-earthism. However, considering flat maps as proof of flat-earthism is an astonishingly foolish argument that would have us classify the creators of Rand McNally maps or the designers of Google Maps as flat-earthers on the grounds that they depict the Earth’s surface as flat. As for cross-sectional representations [“side views”], which could constitute real evidence, they are not derived from medieval manuscripts but are contemporary productions designed to illustrate the myth! The myth thus becomes the creator of its own “evidence.” It perpetuates itself.

The origins of modern flat-earthism

Ironically, the birth of the real flat-earther phenomenon today can be traced back to the 19th century, shortly after the “Enlightenment,” during the rise of rationalism and deep within a utopian socialist community. Indeed, around 1839, Samuel Rowbotham, secretary of the short-lived utopian community Manea Fen inspired by Owenism23, conducted experiments along the Bedford River from which he concluded that the Earth is flat. He published a pamphlet entitled “Zetetic Astronomy” (1849) to defend his bizarre conclusion by appealing to his “zetetic”24 method based solely on reason. He went on to produce a more substantial work (1881) by adding a few Biblical passages that he interpreted very idiosyncratically, citing neither the Church Fathers, nor Cosmas, nor the Middle Ages, and certainly not the Magisterium, for he was a Protestant who seemed to have had no denominational affiliation. His ideas were later embraced by a Protestant sect called the Christian Catholic Apostolic Church, which obviously has nothing to do with Catholicism despite its name, and after that they were taken up by the famous Flat-Earth Society, which continues to exist to this day.


It is disconcerting and revealing to observe that an error as crude as this one could still be so widespread. If such a myth was able to burden the scholarly textbooks for two centuries, how many others are still hiding among contemporary ideas about medieval Christianity? There’s the alleged prohibition of dissection25, the absurd story of the debate about the soul of women26, the myth of the lord’s first night, which Voltaire does not hesitate to attribute to the bishops27, etc. Reality ends up being even harder to discern when objective facts have been taken and mixed up with myth, for example the witch hunts, the Inquisition, or the Galileo affair. All of these myths took root even more tenaciously because they reinforced the preconceived ideas of anti-clericals, whether they revolutionaries or Protestants, even though they talk incessantly about the “battle against prejudice.”

The principal cause of these myths must be sought in this mentality: They judge the medieval period to be irrational because they look at it irrationally. They project their own irrationality onto the past, the better to reinforce the pride of a present day which is deemed to be “enlightened” by reason; out of a prideful Manichaeism, they say the past is “obscurantist” and that we are finally “enlightened.” But the “enlightenment” of the third millennium is not that bright; don’t we see people in high places seriously entertaining the possibility of putting men in women’s prisons or in women’s sports simply because those men have declared that they feel like women? Don’t we see elected officials plead for the preservation of Paris’s “brown rats”? Truly, our world is going to hell in a handbasket. Could the loss of faith have anything to do with this loss of reason? By forgetting this religious verticality that draws man towards God, the Earth today has lost one of its dimensions; it has become spiritually flat.


  • 11. Violaine Giacomotto-Charra and Sylvie Nony, ed. Les Belles Lettres, 2021. We relied heavily on this book.
  • 12. Dictionnaire philosophique (1764), article “Figure.” See also the articles “Ciel matériel” and “Ciel des Anciens.”
  • 13. City of God, XVI, 9.
  • 14. Alphonsi Tostati Episcopi Abulensis, Opera omnia, Commentaria in Genesim (Venice, 1728), p. 71-72.
  • 15. Voltaire added the words “over the Earth,” which are not in the cited verse.
  • 16. Some people bring up Isaiah (40:22) talking about the Lord who “sitteth upon the globe [gyrum] of the Earth.” But since the mere fact of placing God in a sitting position is manifestly an anthropomorphism to be understood in a metaphorical sense, we obviously can’t rely on such a passage to draw out an appropriate literal meaning. We also have the passage from a psalm “I have established the pillars thereof” (Ps 74:4), but Saint Ambrose clearly says about this passage that “we cannot think that it is dealing with real pillars, but rather of that power through which [God] solidifies and supports the substance of the Earth” (P.L. XIV, col. 133).
  • 17. Cf. the Introit of Pentecost: “The Spirit of the Lord has filled the world [orbem terrarium]” (Wisdom 1:7). The Latin term orbis is ambiguous since it can mean both “circle” and “sphere.” It shares the same ambiguity as the word “round”: we talk about a “round Earth” in order to designate a sphere, but we also talk about a “round table” that is nonetheless flat. Accordingly, F. Gaffiot’s Latin dictionary translates the expression “orbis terrae” as “disc of the Earth according to ancient ideas, for us a terrestrial globe.” But it is clear that Mr. Gaffiot is under the influence of the myth. If we examine the texts of the Church Fathers, we see Saint Ambrose for example using orbis lunae and globus lunae interchangeably, which indicates that orbis can indeed signify a globe (P.L., vol. XIV, col. 127 and 200). In the 16th century, scholar and poet Jean-Pierre de Mesmes confidently deduced: “Therefore, we must conclude that the terrestrial mass is round, since its shadow is round: the Holy Prophets confess this when they refer to the Earth in certain places as Orbis terrae” (Institutions astronomiques, chap. 18, p. 54-55).
  • 18. Saint Basil here refers to the opinions of Greek philosophers, as not all of them maintained that the Earth is spherical. Let us quote Copernicus, who enlightens us regarding the authors of these various opinions: “The Earth is not flat, as Empedocles and Anaximenes claimed, nor shaped like a tambourine, as Leucippus suggested, nor like a boat, as Heraclitus proposed, nor hollow in some other way, as Democritus argued. Nor is it cylindrical, as Anaximander believed, nor rooted in the infinite thickness of the lower part, as Xenophanes claimed, but absolutely spherical, as the Philosophers maintain” (Copernicus, De revolutionibus orbium coelestium). The last-mentioned philosophers are primarily Pythagoras, Plato, and Aristotle. Note that human imagination goes far beyond the restrictive duality of disk and sphere.
  • 19. This is the measurement given by Ptolemy in his Geography. He used the Philetaerian stadium measuring 210 meters, which gives a circumference of 37,800km. The real number being closer to 40,070km. Cf. Pierre Duhem, Le Système du monde, t. II, p. 7.
  • 20. Des opinions cosmographiques des Pères de l’Église, in La Revue des deux Monde, t. 1, 1834.
  • 21. Les Somnambules, 1955. Koestler isn’t a historian, but he deserves credit for often consulting the sources…except for the pre-Copernican period where he considers Cosmas an unchallenged authority.
  • 22. “At the very beginning of the Middle Ages, the obscurantism imposed by the Catholic Church enforced the idea that the Earth was flat. But the contemporaries of Christopher Columbus knew that the Earth wasn’t flat.” Lydia Mammar, C’est vrai ou c’est faux ? 300 mythes fracassés (Paris: L’Opportun, 2015), section Avant Christophe Colomb, tout le monde pensait que la Terre était plate.
  • 23. From the name of Robert Owen, founder of Britain’s utopian socialism. Owen saw communities as the only way to live a “rational” life and founded the Rational Society to promote this ideology, advocating for birth control and very liberal views about marriage, among other things. Rowbotham sought the approval of the Rational Society for his community, but was met with no success, even though he had some supporters. The community made headlines and lasted only two years (1839-1841), after which Rowbotham himself deemed these communities as “blameworthy and impractical.” Cf. “A Monument of Union”: Social Change and Personal Experience at the Manea Fen Community, 1839-1841 (John Langdon, 2012).
  • 24. From the Greek zeteo, “I seek.” Like most of those who still use the term “zetetic” today, Rowbotham claims to be supported primarily by experience, although he is more of a theorist. He is not the inventor of this use of the term “zetetic.” In fact, it can be found in the Edinburgh Free Thinkers' Zetetic Society, founded in 1820 by atheist freethinkers from the working class.
  • 25. See the article by Father Knittel: L’Eglise avait-elle interdit la dissection?
  • 26. See the article on the Légende du concile de Mâcon on Wikipédia.
  • 27. The legend was picked up by Michelet. It obviously has no historical basis whatsoever. Cf. Dictionnaire philosophique, Voltaire, article “Cuissage”: “It is astonishing that for a very long time in Christian Europe there existed a kind of feudal law, and people considered it at least a customary right to deflower one’s female vassal. The first night of a peasant girl’s marriage indisputably belonged to the lord... It is undeniable that some abbots and bishops claimed this prerogative as temporal lords.”