Flattening the Earth
Sep-Oct 2002, Mercury Magazine, pp. 34-38.
by Jeffrey Burton Russell
Contrary to popular folklore, medieval Europeans knew Earth was a sphere, and, with the notable exception of Christopher Columbus, most had a pretty good idea of its true size.
One of the few things that everybody "knows" about medieval Europe is that people thought Earth was fiat. The cliché that Columbus discovered that Earth is round is taught so frequently in American grade schools that it has become ingrained in our consciousness.
But for nearly 80 years historians have demonstrated
that medieval Europeans knew Earth to be spherical.
In fact, virtually no educated person in the
Middle Ages (roughly defined as 500-1500 AD.)
believed Earth was fiat. The evidence is as
overwhelming as historical evidence can be.
German historian Reinhard Krueger and other
modern scholars have identified about 100
medieval writings dealing with Earth's shape.
Five seem to assert flatness, and two are
ambiguous. The rest take the globe for granted.
The Columbus cliché is a Flat Error
popularized by the American writer Washington
Some uneducated medieval Europeans may have
assumed a flat Earth, if they thought about
it at all. Since almost all uneducated Europeans
in the Middle Ages lived restricted lives
in small regions, they had little interest
in geography. But a reasonable number of medieval
Europeans were educated, literate, and numerate.
Many had a passing knowledge of astronomy
(not astrology) and logic.
Even among educated people, interest in the
shape of Earth was not high, but they would
have heard that it was a globe and hardly
anyone is known to have disputed this. Interest
in geography in the Middle Ages was mainly
practical or theoretical.Travelers wanted
a road map or sea chart showing how to get
from Oxford to York, say, or from Lisbon to
Genoa. Many such medieval maps of land and
sea exist, but they are only a little more
relevant to the question of Earth's shape
than a street map of Seattle is to Stephen
Hawking's universe. Additionally, philosophers
and theologians wanted to know what God's
universe looked like and how it functioned
(the same desire that eventually sparked the
great expansion of science in the 17th century).
Some of these philosophers were interested
in describing the globe scientifically, both
the parts and the whole.
Cosmology was certainly geocentric before
Copernicus (1473-1543), but geocentricity
and sphericity are two entirely different
issues, both scientifically and historically.
Educated medieval people assumed that Earth
ssas the shape of a globe, just as they assumed
that Earth did not rotate and was the center
of ss hat see now call the solar system.
Medieval theologians had no trouble reconciling
a globe with the Bible. The Bible proclaims
neither a flat nor a spherical Earth. Thus,
there seas no "biblical concept" of
Earth's shape for medieval scholars to either
accept or reject. Furthermore, medieval thinkers,
unlike some modern writers, knew when to take
the Bible metaphorically rather than literally.
Metaphorically is hose they took the few,
differing, and highly ambiguous biblical references
that may suggest a flat Earth (see "Flat
Earth in the Bible:' page 38).
[German cartographer Martin Behain'created
this terrestrial globe in 1492 - several months
before Columbus's discovery of the New World.
This globe alone disproves the common misconception
that medieval Europeans thought Earth was
flat. The globe is housed at the Bibliotheque
Nationale, Paris, France. Courtesy of Giraudon/Art
Resource, New York.]
Of course, ordinary navigators in the Middle
Ages would have wrecked their ships trying
to sail very far on a flat Earth. They knew
that boats disappeared from sight behind the
horizon as they sailed outward and appeared
at the horizon when returning. They knew that
different stars were visible at different
latitudes. They had calculated latitudes,
as opposed to the much more difficult longitudes.
They had also observed Earth's curved shadow
on the Moon during lunar eclipses.
Many medieval maps survive, and although
their details are often crude and inaccurate
by modern standards, the calculations of medieval
geographers and astronomers indicate how medieval
scientists and philosophers viewed Earth and
its dimensions. Many variants existed, but
Earth was typically a globe at the center
of the universe, around which the spheres
of the Sun, Moon, planets, and stars revolve.
Schematically, a medieval map can be divided,
like any globe or ball, into four quarters.
The Eurasian-African landmass was set in the
sea of one of these four quarters. The other
three quarters may be entirely sea or may
contain landmasses. If they have landmasses,
the breadth of the ocean is so great that
passage between them is impossible. If they
do not have landmasses, then the sea runs
west all the way from Portugal to Japan. Earth's
globe is divided into climatic zones: the
Arctic and Antarctic circles are mapped, as
are the tropics of Cancer and Capricorn. Inhabitants
of any of the quarters would meet at the center
if they could descend to the center of Earth.
The quarter diametrically opposite the Eurasian-African
landmass is called the antipodes (meaning "opposite
Medieval tripartite maps are another source
of confusion. These maps show a two-dimensional
surface with Earth divided into three parts:
Asia (one half), Europe (one quarter), and
Africa (one quarter). These maps represent
the quarter of Earth that was believed to
be inhabited, not the whole Earth. Jerusalem
sometimes appears at the center of these maps,
leading historians to falsely assume that
medieval people believed that Earth was a
flat disk centered on lerusalem. But these
maps were intended to illustrate Jerusalem
as the spiritual and moral center of Earth;
they were not meant to he taken in a literal,
COLUMBUS'S DUMB LUCK
The arguments of Columbus's opponents in
the 1480s and 1490s had mostly to do with
the circumference of the globe and the width
of the ocean, and nothing whatsoever to do
with the shape of Earth. Some entertained
the fear of sailing of the edgeof Earth. Rather,
Columbus's opponents argued that the ocean
was too vast for a ship to sail west to Asia
without the entire crew perishing of thirst
and starvation, a dangerous gamble on which
to risk life - and the royal treasury. It
was quite a reasonable argument, and Columbus
had to work hard to overcome it. He accomplished
this by scientific legerdemain, political
luck, and something nobody expected.
First, Columbus adopted Ptolemy's smaller
Earth against Eratosthenes' larger and more
correct Earth. Next, he chose an argument
by the 4th-century theologian and politician
Pierre D'Ailly that the Eurasian landmass,
rather than occupying only a half of the Northern
Hemisphere (180°), actually occupied 225° (versus
135° for the sea. He then argued that
Marco Polo's travels showed that the landmass
stretched 28° more, and that Japan lay
30° east of China, reducing the ocean
to 77°. Next, he subtracted 9° of
sea because he planned to depart from the
Canaries rather than from Spain or Portugal.
Now, he was up to 292° of land versus
68° of sea. He decided that D'Ailly's
original estimate for Eurasia was 8° too
small, and voila, Columbus ended up with 3000
of land versus 60° of sea. Finally, Columbus
switched from Arabic miles to shorter Roman
miles. He audaciously concluded a figure for
the sea's width equal to about 4,450 kilometers,
about one fifth the actual distance between
Portugal and Japan of about 22,000 kilometers.
Not many believed such preposterous calculations.
But Columbus was in political luck. The Portuguese
were exploring and developing the coasts of
Africa, the Portuguese and Spaniards were
locked in commercial and political rivalry,
the Spaniards had just defeated the Muslims
in Spain and expelled the Jews, and now they
were eyeing new ways to expand their wealth
and power. So King Ferdinand and Queen Isabella
of Spain approved the crazy adventure, and
in 1492 Columbus set sail across the Atlantic.
Then came one of the greatest pieces of luck
in human history: on October 12, 1492, Columbus
blundered into the Americas under the mistaken
impression that he was encountering the East
Indies. Otherwise, he and his crew would surely
have perished at sea as the scholars had predicted.
Columbus went to his grave believing he had
traveled to the Far East.
[Washington Irving authored a highly fictionalized
19th-century biography of Christopher Columbus
that fooled readers into believing that Columbus
proved Earth was round. Irving and his book's
title page are shown above. Courtesy of Jeffrey
THE ERROR'S ORIGIN
What happened to the Flat Error after 1794,
when Paine's book was published, is fairly
clear, it was mentioned by a few writers and
then was popularized in France by Antoine-Jean
Letronne and in the English speaking world
by Washington Irving. Irving was the author
of the beloved Headless Horseman and of a
number of fraudulent and heavily fictionalized
histories of New York City, George Washington,
and Christopher Columbus. Irving invented
the still widely believed melodrama of Columbus,
a lone hero of science, standing against the
bigoted and ignorant courtiers and clergy
of the Council of Salamanca, who told him
the world was flat. Irving's account of this
nonexistent council is fiction, but the fiction
caught on with those wishing a handy stick
with which to beat the Catholic Church and
the "ancients:' After all, we always
like to believe that earlier people were stupider
than we are. For example, some of our contemporaries
believe that Egyptians must have been too
primitive to have built the pyramids by themselves,
so they must have had help from extraterrestrials.
The silliness would probably have faded away
but for the appearance of something else no
one expected: the theory of evolution. In
the early 19th century, the notion of slow
geological change gained strength, and by
mid-century Charles Darwin and Alfred Russel
Wallace introduced the idea of biological
evolution. Scientific doubts raised at the
time are perfectly understandable in the context
of the age. But other objections came from
Christians who insisted on taking the entire
Bible literally, which medieval Christians
had not done. These antiDarwinists assumed
that the creation story in Genesis was supposed
to be a literal, scientific, and physical
account of the beginning of the world, and
because they believed the Bible to be without
error, they had to reject evolution. Evolution's
supporters, who apparently believed Irving's
tale, claimed that evolution's opponents were
just as stupid as medieval Europeans who allegedly
thought Earth was flat. From there, the Flat
Error found its way into textbooks, stories,
and even a few encyclopedias, where it fit
so nicely into what else we know most of it
false about the Middle Ages.
As astronomer Steven N. Shore of Indiana
University, South Bend, observed, "Facts
are only the raw material of history:' And
when scientists and historians get the basic
facts wrong or fail to correct the record,
the finished product is as distorted as a
JEFFREY BURTON RUSSELL is Professor of History
Emeritus at the University of California,
Santa Barbara. He is the author of Inventing
the Flat Earth and numerous other books and
articles on history, religion, and science.
One has to look long and hard to find biblical
passages that refer to the shape of Earth.
The only two passages to be found that do
so are quite vague, explaining why it was
easy for medieval Christians to accept that
Earth was a globe.
He sits enthroned above the circle of the
earth, and its people are like grasshoppers.
He stretches out the heavens like a canopy,
and spreads them out like a tent to live in.
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