Many today believe that people in the Middle Ages believed in a flat earth. They say that Christopher Columbus was considered by many people to be crazy because he might fall off the edge of the earth, where there may have been dragons or other fearsome creatures.
In reality, people did not believe in a flat earth during the Middle Ages. They believed the earth was a sphere. There is no record of anyone criticizing Columbus for going on an expedition that would have him fall off the edge of the earth. In fact, the Greek thinker Eratosthenes had already calculated the circumference of the world within about 2%, and the Greek knowledge of this had not disappeared during the Middle Ages. Aristotle, who was held in very high esteem by the Medieval scholastics, also believed in a spherical earth. This story was a myth created in the 19th century.
The reason King Ferdinand and Queen Isabella or Spain were skeptical of his journey to Asia by going west was not that the earth was flat and that he would fall off the earth. It was that Columbus’ calculation of the circumference of the earth was wrong, by a whopping 32%. They thought that Columbus would die because the distance was too long to travel without adequate provisions. In fact, if the New World had not been between Europe and Asia, Columbus and all his men probably would have died at sea.
According to the book Inventing the Flat Earth: Columbus and Modern Historians, by Jeffery Burton Russell, the two largest culprits of spreading the myth were Washington Irving and Antoine-Jean Letronne. Irving wrote historical fiction and sometimes blurred the lines between fiction and reality in his stories. Antoine-Jean Letronne was taught by humanists who had a low opinion of the Catholic Church and the Middle Ages, and this view of the Middle ages fit in with his worldview. Another factor leading to the spread of the myth was the fact that several historians quoted other secondary sources without question. Two of these historians are Daniel Boorstin and Andrew Dickson White. The secondary sources they quoted propagated the myth themselves.
The myth-makers cite two people: Lactantius (c. 245-325) and Cosmas Indicopleustes. Neither of these people had any influence whatsoever. Cosmas was not even translated into Latin until the 18th century. Lactantius was a Christian heretic and a former pagan. He was persuaded that the pagans had no good arguments for the sphericity of the earth. As a convert from paganism, he also had an anxiousness to portray the pagans as wrong about everything.
Cosmas was a Greek traveler and geographer who lived in the sixth century AD. Cosmas drew a flat diagram of the world when he was trying to bring out a spiritual meaning of the universe. He was criticized by other Christian contemporaries for making it look like Christians believed in a flat earth, which they took to be utterly false. Most reference works have dropped the claims that people in the Middle ages believed in a flat earth, but it still propagates today in some sources. It is even in some school textbooks.
In the essay “Questions of Conquest”, by Mario Vargas Llosa. In the essay, Llosa explains how the Spaniards were able to defeat the Aztec and the Inca empires with only small groups of invaders. Even though the Spaniards had guns, horses, and armor, it is incredible that they were able to conquer these vast empires with only small groups of men.
These empires were different than the scattered tribes of North America or the Caribbean islands. They were highly developed civilizations that were in some ways more developed than Spain. The Incas, for example, had an elaborate road system, an impressive knowledge of mathematics, as well as great engineering ability. They had a high level of social, military, and agricultural development.
The Indians living in these empires were taught their whole lives to obey the emperor. In these societies, all people and property were subject to the emperor and were dedicated to his service. There was little space for individual thought. They did great things as an empire, but it was always collective, like an army of ants. Once the emperor was gone, they did not know what to do or how to act. Thus, if the Spaniards could kill the emperor, then they could easily dominate the rest of the army in battle.