Professor Norman Swartz
Simon Fraser University

The Myth of the Flat Earth

October 7, 1995

Last week I posted a letter, to the PHILOSOP email discussion group, about an earlier thread concerning the myth of the flat earth. Bernard Katz, who initiated the thread, helped me to track it down and furnished many of the threads, several of which were sent to him offline. Thanks, Bernard!

I have assembled all the threads (see below) and have edited them – removing most of the headers, retaining only enough to identify the authors and the date; and I have snipped out quotes from previous links in the thread. If any of you want/need the excised bits, write to me, and I can send you the original, unedited, posting (together with the return email address of the author).

Unless explicitly noted to the contrary, each item was posted to the mailgroup PHILOSOP. At the very end, I have appended some recent items from the mailgroup LOGIC-L. In the latter case, I have not re-constructed the entire thread since much of it had to do with logic, not the shape of the earth.

I am sending this file to all of you who explicitly asked for it and to many of the persons who contributed to the threads. (Unfortunately, some of the email addresses from 1992 have 'gone stale'.)

Norman Swartz
Department of Philosophy
Simon Fraser University
Postscript (Jan. 30, 1996) – Robert J Schadewald has continued the thread in letter to me. With his permission I have appended it to the end of this file and posted it on PHILOSOP.

Date: Mon, 23 Nov 1992
From: Bernard Katz

Many recent articles in the popular press have suggested that until shortly before Columbus's voyage in 1492 it was widely believed that the Earth was flat. One of my colleagues, however, contends that this is at least partly a myth; he claims that at no time in the history of western culture did educated people think that the Earth is flat.

Does anyone know of any counterexamples?

Date: Mon, 23 Nov 1992
From: Ron Amundson

Bernard Katz asks for counterexamples to the claim that "at no time in the history of western culture did educated people think that the Earth is flat." Counterexamples will turn on the definition of "educated" of course, but I refer him to Owen Gingerich's article "Astronomy in the Age of Columbus" in the November 1992 Scientific American.

Gingerich says that the myth of the pre-Columbus belief in the flat Earth was singlehandedly invented by Washington Irving! Neato. I've known that it's an myth ever since I started reading in the history of astronomy, but I had no idea that the guy who invented the Headless Horsemen also invented the Flat Earth.

G. says that Irving was casting about for a new hero-of-origin to replace the English explorer Sebastian Cabot, the first Englishman (and first European?) to make landfall on the North American continent. This was just after the American Revolution. So Irving found out some facts about Columbus, and invented the rest.

G. says: "In reality, knowledge of the earth's round [he means spherical] shape was always part of the Western heritage."

And there are pretty simple ways to demonstrate it, involving lunar eclipses and relative positions in the sky of stars as seen from different locations.

The motion of the earth, of course, is a very much harder thing to demonstrate. It illustrates our common ignorance that we associate mistakes about the shape of the earth with mistakes about its motion. They're very different things.

As a result of these researches, I no longer believe in the Headless Horseman.

Date: 23 Nov 1992
From: Gordon Welty
To: Bernard Katz

I don't have my books handy now, but can send along references to the effect that during the Abbassid Caliphate in Baghdad, ca. 800 A.D., the 'scientists' knew the earth was round, and developed a very sophisticated technique to measure the diameter. Whether this was diffused to all the populace is another question.

Date: Tue, 24 Nov 1992
From: Nelson Pole

I remember my Captain Kangaroo lecture on the flat Earth. According to the Captain, Aristotle proved that the Earth was round. There are several arguments but the best is the ship coming into the harbor one. As a ship appears on the horizon, an observer first sees that top of the ship's mast and then later the deck. It is as if the ship is coming over a hill. Hence the Earth is shaped like a hill. Since this phenomenon is true in every harbor that the greek sailors visited, the Earth must be everywhere hill-like or round. I really heard this on Captain Kangaroo!

Date: Tue, 24 Nov 1992
From: Tze-wan Kwan

The Greeks were among those who speculated much about the shape of the Earth. As is well known, Thales claimed that the Earth was flat whereas Anaximander made it a "stone column". The earliest claim for the round shape of the Earth known to me came from Pythagoras. It was reported that Pythagoras reasoned from the perpetual round shape of lunar eclipses that the Earth could neither be flat nor cylindrical, but only spherical. Please refer to John Burnet's Greek Philosophy Part 1: Thales to Plato. (London: MacMillan, 1914), P.44. Similar views can be found in Aristotle's opus.

Date: Tue, 24 Nov 1992
From: Orville G. Marti

Cosmas Indicopleustes wrote a book called "Christian Topography" in which he claimed the earth is flat. Below are appended 1 translation, the (original?) Latin and another translation. I also attach a comment from another source suggesting that Cosmas' original was in Greek, not Latin. I hope this helps.

"Although the figure of a man is upright, somehow it happens that those four are not standing upright at the same time; but wherever you turn them, those four never appear at once; so how can it be that we entertain these empty and false hypotheses? So how can it be that the rain falls on all four of them at once? So why do you vainly propose what neither our nature nor our mind can accept?" —Cosmas

"Cum figura hominis recta sit, qui fit ut quatuor illi eodem tempore stantes recti non sint; sed quocumque vertas eos, quatuor illi simul nunquam videantur; quomodo ergo fieri potest ut vanas illas mendacesque hypotheses admittamus? Quomodo ergo fieri potest ut eodem tempore pluvia in quatuor illos decidat? Quod ergo nec natura nec mens nostra admittere potest id cur frustra supponitis?"

—Cosmas Indicopleustes "Christian Topography"

There is one old English translation of Cosmas that I have not seen, by I think E.O. Winstedt. The only serious modern work are the two publications of Wanda Wolska-Conus, her dissertation and her Sources Chretiennes edition with French translation of the original Greek text. Where this Latin comes from I'm sure I don't know, but that Latin whatever it is would render about like this: (source unknown)

Since the figure of man is erect, how does it happen that those four standing at the same time are not erect; but however you turn them, those four are never seen at the same time; how therefore can it be that we admit those vain and mendacious theories? How therefore can it be that at the same time rain falls on those four? What neither nature nor our mind can allow, why do you imagine it in vain? —Cosmas

"Those four" refers to 4 figures of men standing on a model of the earth. Obviously, according to Cosmas, only one of them can be "upright", therefore whence this notion of a spherical earth?

Date: Tue, 24 Nov 1992
From: Prof. Rega Wood

Medievals regularly cited with approval Aristotle's statement that the earth is round. An example is Adam de Wodeham: terra rotunda est. This example comes from Wodeham's theology lectures (Lectura secunda, d.1 q.3) where he is discussing the question whether the same conclusion can be proved in different sciences. The physicist and the astolog both prove that the earth is round; the physicist by reference to gravity.

Date: Tue, 24 Nov 1992
From: Ron Amundson

Jack Sanders writes:

>I doubt that the "flat earth" story was invented by Washington Irving. The
>idea of a flat earth was espoused by some of the leaders of the Christian
>church in the fourth century, notably Cyril of Jerusalem and Diodorus of

and others mention other early flat earthers. I must clarify my report of Gingerich's words:

Gingerich says that Irving invented the story that Columbus had to convince flat-earthers that the earth was round in order to get backing for his trip. This story was false, and Gingerich [added Oct. 8, 1995 – Amundson says he meant "Columbus", not "Gingerich" – NS] made it up. He presumably did not "make up" the story that other people (educated or no) had earlier believed that the earth was flat.

Apologies for my ambiguity.

Date: Wed, 25 Nov 1992
From: Nollaig MacKenzie
To: Bernard Katz

I once browsed, trying to find such a person after (say) 400 BC in "Western" tradition. Seem to remember that Lactantius (c. 700 AD??) thought – on Biblical grounds – that the world was not spherical.

Date: Thu, 26 Nov 1992
From: Adriano P. PALMA
To: Bernard Katz

I did find out some printed sources (there are two manuscripts in florence (italy) nat.lib. which explictly claim that the planet is flat (and that, interestingly enough, people on the other "side" are suffering constant headaches —,given their positions...) . I have seen them a long time ago (their date is circa 1290) but I could track them down if you care to. I am not aware of any serious scientific point made out of it.

most people assumed, (from post classical times) that the planet is one of the "aristotelian" spheres and that was somehow taken to be the correct opinion even in orthodox religious circles. sorry not to be of more help

Date: Fri, 27 Nov 1992
From: Keith Hutchison
To: Bernard Katz

The details of the book are:

Russell, Jeffrey Inventing the flat earth: Columbus and modern historians 10/9/92 New York Praeger 1991 {16} Some belief in disc-earth in France before 1300: cites (n. 40, p. 85) TATTERSALL, 'Sphere or disc?', p. 46. {84} Note 36. Mandeville (French ch. 20 = Penguin pp. 129-130) seems to allow that 'simple people' believe that one would fall off the earth at the antipodes. {88} Note 59 cites some important Biblical cosmological passages: Deut. 5:8; 13:7; 28:64; 33:17; I Samuel 2:10; Psalms 48:10; 61:2; 65:5; 88(89):11-12; 98:3; 103(104):3 +=? 104:2-3; 135; Proverbs 17:24; 30:4; Isaiah 5:2; 11:2; Jeremiah 25:33; Job 37:3; Ezekiel 7:2; Revelation 7:1; 20:8. Elsewhere cites Isaiah 40:22; Job 22:14; Amos 9:6; Matthew 24:31. {90} N. 79 refers to a legend that volcanoes near Iceland were an opening into Hell. No documentation.

It is an excellent discussion. In notes above numbers insid{} represent page numbers.

Like you I am interested in counterexamples to JRs claim, but his book has made it seem hard to find such.


PLINY, Natural history, II.161-6 clearly indicates that some people did not believe in a spherical earth. Or is it just oppositon to the belief that the antipodes are inhabited?

TACITUS, Germani, 45 talks of the sun setting into the sea, and Tacitus at least is educated.

Luther believed that the oceans were higher than the land, and that it was a perpetual miracle that they did not flood the land. Behind this lies a belief that the surface of the earth-water globe is circular but that gravity acts as if the earth were flat.

You get a similar confusion in MANDEVILLE's travels – chapter 42, and in chapter 30 he speaks of a high mountain so high that it reaches the moon. I.e. the earth is not spherical. Columbus himself comes to a similar conclusion, and argues for a pear-shaped earth. Dante too has a mountain of purgatory which is sufficiently large that the earth is not spherical.

Date: Sat, 5 Dec 1992
From: Zeno Swijtink
To: Bernard Katz

Looking thru a on-line library catalogue I noticed the following reference on the flat earth myth (if you are still interested)

Inventing the flat earth : Columbus and modern historians / Jeffrey Burton Russell ; foreword by David Noble. – New York [etc.] : Praeger, 1991. – xi, 117 p. ; 22 cm

Date: Tue, 8 Aug 1995
From: Paul Jonathan Hollander
To: logic-l

On Tue, 8 Aug 1995 wrote:

> Correct me if I'm wrong here – was not Aristotle a well respected logician?
> Did he not entertain thoughts that the earth may be flat? Was he SURE it was
> round? Did he not think that the earth was the center of the universe (and
> flat)?

Aristotle was and still is a well-respected logician. He does not appear to have believed that the Earth was flat, however. In De Caelo (On the Heavens) he attempts to construct an a priori argument as to why the Universe must have the general structure it does (De Caelo II.3), a structure which included for him a spherical Earth at its center (De Caelo II.13-14). Aristotle seems to have agreed with estimates that the circumference of the Earth was 400,000 stades (approximately 46,000 miles, if I'm not mistaken) (De Caelo II.14 298a15).

If I remember correctly, it was Aristarchus of Samos, an Alexandrian mathematician and astronomer who flourished around 280-264 B.C., who devised a geometrical method for determining to a relatively high degree of precision the circumference of the Earth, by comparing the shadows cast by sticks of the same height, located at the same longitude and measured at the same time of the same day, set at a determinate distance from each other. Not only did the ancient Mediterranean world know that the Earth was round, but they had a method for determining its circumference as well.

Also, if I remember my Western Civ. correctly, the comment Aristotle makes at De Caelo II.14 298a9-15, that the ocean to the west (i.e. the Atlantic) quite possibly connects with India, was known to Columbus and helped convince him that the Earth was round. Such terms as 'West Indies' and 'Indian' (meaning Native American) would seem to be due in part to Aristotle.

Date: Tue, 8 Aug 1995
From: Mike Allenbaugh
To: logic-l

[snip – see above, N. Swartz]

Thank you for the reasoned response. I believe that a goodly number of Aristotle's contemporaries were going against the accepted line of thought and exploring the idea of a spherical earth. A classic case of having to allow hard evidence to overcome established belief. No harm in that. I am surprised that it took so long for a scientist to be able to state unequivocally that the earth was a sphere and not be the subject of ridicule From people who had not properly evaluated the evidence available to them at the time.

I have often imagined Einstein evaluating Hubble's proof of an expanding universe and saying to himself "why didn't I think of that"? Certainly prisms were avaiable to Einstein, Gallileo and, probably, Aristotle. Do you suppose no one noticed the "red shift" before Hubble or do you think they simply were not able to interperet it?

Date: Wed, 9 Aug 1995
From: Winfield Featherston
To: logic-l


Hmm...I thought it was Eratosthenes who estimated the circumference of the earth by applying geometric methods to measurements of the difference between shadows cast in Alexandria and Cyene. I could be mistaken, though.

Date: Wed, 9 Aug 1995
From: Paul Jonathan Hollander
To: logic-l

On Wed, 9 Aug 1995, Winfield Featherston wrote:

[snip – see above]

Aha! I believe you are correct! Much of my reference material is boxed up, so I ended up guessing on that one. In Sir William Smith's 1909 volume, A Classical Dictionary of Greek and Roman Biography, Mythology and Geography, one finds the following written about Eratosthenes.

[O]f Cyrene, was born B.C. 276. He first studied in his native city and then at Athens. He was taught by Ariston of Chios, the philosopher; Lysanias of Cyrene, the grammarian; and Callimachus, the poet. He left Athens at the invitation of Ptolemy Euergetes, who placed him over the library at Alexandria. Here he continued till the reign of Ptolemy Epiphanes. He died at the age of 80, about B.C. 196, of voluntary starvation, having lost his sight, and being tired of life. He was a man of vey extensive learning, and wrote on almost all branches of knowledge then cultivated — astronomy, geometry, geography, philosophy, history, and grammar....His works have perished, with the exception of some fragments. His most celebrated work was a systematic treatise on geography, entitled Geographika, in three books. The first book, which formed a sort of introduction, contained a critical review of the labours of his predecessors from the earliest to his own times, and investigations concerning the form and nature of the earth, which, according to him, was an immovable globe. The second book contained what is now called mathematical geography. He was the first person who attempted to measure the magnitude of the earth, in which attempt he brought forward and used the method which is employed to this present day. The third book contained political geography, and gave descriptions of the various countries, derived from the works of earlier travellers and geographers....Connected with this work was a new map of the earth, in which towns, mountains, rivers, lakes, and climates were marked according to his own improved measurements. This important work of Eratosthenes forms an epoch in the history of ancient geography....Eratosthenes also wrote two poems on astronomical subjects....He wrote several historical works...and a grammatical work. (pp. 321-2)

Date: Wed, 9 Aug 1995
From: Clifton McIntosh
To: logic-l


Aristotle, and Greek astronomers in general, knew that the earth is round. In his Physics Aristotle gives two or three arguments. One is from the shape of the earth's shadow on the moon during an eclipse of the moon. Another is from the well known phenomenon of a ship's leaving port — the ship soon is lost to view but the sails of the ship are visible for quite a while longer. Finally (from my memory), the Greeks knew that people located on a high promontory could see considerably farther out to see than someone low. All these Aristotle regards as settling the shape of the earth empirically.

Incidentally, on the eclipses of the moon, one of the more ingenious geometric cum astronomical arguments uses the length of time the moon is eclipsed during a total eclipse to estimate the distance of the sun from the earth.

The Greeks were no slouches in astronomy. Even the view that the earth is at the center of the universe was argued for, not just assumed.

Date: Tues., Jan. 30, 1996
From: Robert J Schadewald
To: Norman Swartz (forwarded, in turn, to PHILOSOP Feb. 4, 1996)

Don Simanek, who well knows my long-time interest in flat earthism, forwarded a copy of your recent flat earth recapitulation message to me, and I can't resist a few comments. As the printout runs nine pages, I won't try to include everything I might say, so silence on any point does not necessarily constitute agreement. On the other hand, I don't find much with which to disagree, but there are many points I must resist the temptation to amplify or clarify.

The various remarks about the Greeks and the discovery of the spherical form of the earth are, so far as I know, essentially correct. The spherical conception of the earth was unknown prior to the 5th century B.C., and it appeared early (if not necessarily first) among the Pythagoreans. A powerful idea, sphericity seems to have triumphed almost completely in about a century, and Aristotle probably considered his proofs of sphericity in On the Heavens common knowledge among the educated. I would be delighted to learn of examples of "serious" (and non-Christian) philosphers after his time who rejected sphericity.

On the other hand, the ancient Hebrews, like all of their contemporaries, were flat earthers, and their flat earth cosmology is written between the lines in numerous passages of the Hebrew Bible. This was not lost on many of the Fathers of the Church. Lactantius, Cyril of Jerusalem, and Diodorus of Tarsus have been correctly cited by others as flat earthers. I could name many more, some minor figures, some major (John Chrysostom, for example, and probably Basil of Caesarea). Flat earthism seems to have been uncommon among the Latin Fathers (Tertullian seems to have been one exception). Among the Greek Fathers, the Alexandrians tended to interpret scripture allegorically, and they likewise could accept sphericity without a problem. The Antiochene theologians, however, originated the grammatical-historical interpretation of the Bible beloved by modern fundamentalists, and I can't name a single one of them who endorsed sphericity but several who condemned it. The Old Syrian Church seems likewise to have been hostile to sphericity. (Jeffrey Burton Russell's treatment of the Fathers' views on the shape of the earth is no more reliable than Andrew Dickson White's, though he castigates White for inaccuracy.)

Contra Russell, who portrays Cosmas Indicopleustes as a weird latter-day (c. 548) innovator, I think Cosmas (who wrote in Greek, not Latin) preserved a minor but interesting tradition. He says in his book that he learned his system from the man who later became Bishop Catholic of all of Persia (head of the Nestorian Church). For those interested in Cosmas's views, I was astonished some weeks ago to find a Web page with the English (and Greek) text of the crucial chapter of his Christian Topography, complete with scans of all the illustrations! The URL is:

My real interest in all of this is the modern flat earth movement, which I have been studying for about two decades. Don Simanek has three of my publications on the subject available on his homepage, URL:

If anyone has information on flat earthers from the last few centuries — especially living flat earthers (other than Charles Johnson) — I would be delighted to hear from them. (

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