In medieval times, there were very few scientists in Western Europe. The folks who were saying the world was flat were Catholic clergy.
That is history done with all the rigor of global warming science.
If you open up St. Thomas Aquinas’ Summa Theologiae, on the very first page he speaks of the differentiation of the sciences, explaining how the same fact may be shown by different sciences, and the examples he uses are how both the astronomer and physicist demonstrate that the earth is round, but by two different means. That work, written ca. 1270, was the standard work for training Catholic clergy for centuries.
When Columbus proposed setting sail for the new world, he did run into opposition from the clergy, not because they thought the world was flat, but because they had a fairly good idea of the circumference, as well as the location of the eastern edge of Asia—and if you put those two things together you need a great deal more water and food than Columbus was capable of carrying—sort of like setting out for the moon with a two-day supply of oxygen. Columbus argued that the circumference was actually much smaller. Columbus was wrong, but was fortunate enough to run into the new world.
Where did the flat earth myth come about, you may wonder? Washington Irving set out to write a popular history of Christopher Columbus, and found that the actual events were too complicated and too pro-Catholic—so he made up something that he thought would fly. Andrew Dixon White, first president of Cornell University (my alma mater) either bought into it or found it convenient, and between the two of them, it has become an impossible to eradicate myth. A quite convenient myth, in that it allows one to adopt an intellectual position that doesn’t have to bother with anything before the enlightenment.
If you want more details, read Inventing the Flat Earth: Columbus and Modern Historians by Jeffrey Burton Russell.
I was trying to do three things at once yesterday and shouldn’t have been posting here.
My first degree was actually in history, and in my mind, alongside 10 other things I was doing at the time, I was mixing up Galilean heliocentric science and flat earth theories. Neither which had much to do with one another.
I’m well aware that mapmakers in the days of Columbus and especially those of Prince Henry the Navigator were well aware that the world was round due to Arab (old Caliphate maps) and Greek maps obtained by trade with the Byzantines and Venetians, and/or by the so-called “Reconquista” of Portugal and Spain.
In short, I shouldn’t attempt to multitask. I’m terrible at it and always have been. You are a 100% correct. The early 15th century argument was over the circumference - not the shape of the earth.