Prologue: The Ancient View of the Earth
When Columbus sailed in 1492, he knew he could safely reach the Indies by sailing west. His crewmen were less confident. Fearing they would slip down over the edge of the globe, never to return, they nearly mutinied. Columbus finally convinced them that their fears were groundless, for the earth is flat. The rest is history. Columbus and his ships sailed safely across the flat sea and reached America. Or so Charles K. Johnson, late president of the Flat Earth Society, told the story. (The orthodox version of the story, of course, is that Columbus believed the earth was spherical, but his crew didn’t share his belief, and feared that they might sail over the edge of a flat earth!)
The spherical heresy has incensed literal-minded Christians since time immemorial; for the flat-earth cosmology the ancient Hebrews borrowed from the Babylonians is implicit throughout the Bible. The modern flat-earth movement arose in 19th century England as a reaction against the burgeoning fields of astronomy and geology. Its philosophy is summed up by a bumper sticker now popular among fundamentalists: “The Bible says it. I believe it. That settles it.”
Before the dawn of history, those people who gave the matter any thought probably concluded that the earth was essentially flat. From any sort of hill, the calm surface of the ocean looks flat as a flapjack. It’s not surprising that none of the early cosmologies which are still preserved—Sumerian, Babylonian, Hebrew, Egyptian—describe a spherical earth.
The Babylonians believed that the universe consists of a reasonably flat earth surrounded by water, with the whole covered by a huge dome. According to their cosmology, water is above the dome and below the earth. The celestial bodies are gods and goddesses, and their movements and positions with respect to one another have profound effects on mundane affairs. This cosmology and its associated astrology were common to much of the ancient Middle East. The essence of the Babylonian cosmology was adopted by the ancient Hebrews and it underlies the text of the Bible.
Nowhere does the Bible explicitly mention the earth’s shape, but it is a flat-earth book from beginning to end. Thus in Genesis 1:6, “God said, ‘Let there be a vault between the waters, to separate water from water.’ So God made the vault, and separated the water under the vault from the water above it, and so it was; and God called the vault heaven.” Also, the order Genesis ascribes to creation—earth on the first day and the sun, moon, planets, and stars on the fourth—makes no sense in the light of our present cosmology. But it’s perfectly reasonable to a flat-earther. Elsewhere, the Bible comes closer to explicitly describing the earth’s shape. Thus Isaiah 40:21–22 says, “Do you not know … that God sits throned on the vaulted roof of earth, whose inhabitants are like grasshoppers? He stretches out the skies like a curtain, he spreads them out like a tent to live in …” Numerous passages state that the earth is immovable and others treat the sun and moon as minor bodies. In the New Testament, the presumed shape of the earth is evident in the story of the temptation of Jesus. According to Matthew 4:8, “Once again, the devil took him to a very high mountain, and showed him all the kingdoms of the world in their glory.” The word translated as “world” is the Greek kosmos, meaning the whole universe. From a sufficiently high mountain, one could see all the kingdoms of a flat world of limited extent, but the passage is nonsense when applied to a spherical earth. The same is true of Revelation 1:6, “Behold, he is coming with the clouds! Every eye shall see him …”
But the flat-earth theory was already passé when the New Testament was written. The Greeks are usually credited with proposing that the earth is a globe. Pythagoras and some of his followers even suggested that it rotates around the sun rather than the other way round. By the fourth century B.C., the globular opinion dominated Greece. Aristotle offered three proofs that the earth is a globe: (a) ships sailing out of port seem to disappear over the horizon, (b) sailors voyaging far to the south see stars above the southern horizon that aren’t visible from more northern latitudes, and (c) at a lunar eclipse, the shadow of the earth on the moon is curved.
The concept of a spherical earth found favor in the Hellenic world and even among some of the early Jews. But then, as now, many were determined to cut science to fit their Bibles. The Fathers of the Church were not unanimous about the shape of the earth. Lactantius and Epiphanius insisted that the earth is flat; Clement of Alexandria and Origen insisted that it is round. But the majority thought it was flat. Apparently, Eusebius was also a great flat-earther, and he may have been of special importance to Cosmas Indicopleustes, of whom more presently. For a couple centuries, these worthies tried to stamp out the spherical heresy among the faithful, bombarding them with verses like those already quoted.
This first phase of the Christian flat-earth movement peaked early in the 6th century, when the Egyptian merchant and monk Cosmas Indicopleustes wrote his Christian Topography. Cosmas argued that the earth’s surface is a rectangle, surrounded by seas, and covered by a vaulted roof. Indeed, the Cosmas cosmos looked essentially like a steamer trunk. It measured four hundred days journey east and west by two hundred north and south. Far in the north lay a great conical mountain behind which the sun disappeared at sunset. Rain fell from windows in the vaulted roof, and angels propelled the heavenly bodies on their ways.
The Cosmas cosmos was common sense cosmology. As already stated—but it deserves emphasizing—from any sort of hill, the ocean does look as flat as a pool table.
Cosmas got many of his arguments (and perhaps some of his odium theologicum) from the Fathers of the Church, notably Lactantius and Theodore of Mopsuestia. Cosmas took the shew-bread table in the Jewish tabernacle as his model of the earth, flat and twice as long as it was broad. He argued from scripture that the sun must be near and small, since it moved backward for Hezekiah. Again, according to the Bible (Revelation 1:6, quoted above), everyone on earth will see Jesus coming through the clouds when he returns in glory. Obviously, that’s impossible if the earth is a sphere. Near the end of Christian Topography, Cosmas wrote, “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.”
Despite his powerful allies, Cosmas was fighting a losing battle. The geographical and astronomical–astrological works of the spherical Ptolemy had mostly taken over well before he wrote his great work. A century later, the great churchman Isidore of Seville sided with Ptolemy in his De Natura Rerum. In the 8th century, the Venerable Bede adopted the sphere. Later, Albert the Great, Thomas Aquinas, and Roger Bacon all rejected the Christian Topography. The revolution was quiet but thorough, and within a few centuries the ancient Hebrew cosmology had died out among the educated. By the late Middle Ages, the question was considered settled, and theologians had to content themselves with wrangling over whether the antipodes—lands on the other side of the globe—were inhabited.
Such was the situation when Columbus showed up in the Spanish court, hat in hand. The dramatic story of his debate with Spanish scholars there is from Washington Irving’s History of the Life and Voyages of Christopher Columbus, and it’s every bit as historical as “The Legend of Sleepy Hollow.” What problems Columbus had with his crew during the voyage seem to have been unrelated to the shape of the earth, though, as we saw in the opening paragraph, Charles Johnson disagreed.
By the time Galileo tangled with the Inquisition, Magellan and others had circumnavigated the globe, and these voyages stilled most lingering doubts about the earth’s shape. Galileo got in trouble, not for claiming that the earth is round, but for arguing that it is not the center of the universe. This dispute set the pattern for the next two hundred years, during which fundamentalists directed their efforts toward smashing the ungodly Copernican system and returning to geocentricity. (We’ll discuss this ongoing effort in a later chapter.) Except for a few isolated individuals, no one seriously challenged the spherical assumption. Until, that is, the nineteenth century ….