Yes, he was trying to reach Asia (Japan actually), I do not think anyone was arguing that point. But no European had ever been out of sight of land for 5, 10 days at the MOST. In one shot he tripled that number while proving the theory that Atlantic ocean was not endless. It was just a theory at the time.
As late as 1503 Pope Alexander VI still understood the world to be flat. In fact, after the Columbus voyages he decreed that Portugal could not claim land by crossing a particular meridian (ignoring the fact they could sail West and claim the land on the other side of said meridian). Magellan himself stated in 1518, "The Church says the Earth is flat, but I have seen its shadow on the Moon, and I have more faith in a shadow than I do in the Church."
(
Discarded Science: Ideas that Seemed Good at the Time. John Grant. Facts, Figures & Fun (October 28, 2006). pp. 30-33.
The bible comments several times that an individual stood upon XYA mountain and looked down upon the whole of the earth (eg. Matthew 4:
. Or that the Earth is a circle (Isaiah 40:22). Or that it has four corners (Isaiah 11:12). The Church professed that the Earth was a flat disc with Jerusalem (sometimes Rome) at its center. It was certainly possibly to fall off the ends of the earth (Job 38:13).
Of course the Greeks new the Earth was a sphere as early as 570 BCE. The bane of high school geometry Pythagoras reasoned that everything in nature found harmony, and the Sphere is the most harmonious shape. Therefor, planets must be spheres. The earth was another planet, therefor the Earth is a sphere. IN fact, the Greek Eratosthenes got within 1% of the actual circumference of the Earth.
Plato studied under Pythagoras, Socrates under Plato, Aristotle under Socrates, and Aristotle was the teacher of Alexander. Alexander conquered most of the known world and passed that knowledge on - notably to Ptolemaic Egypt. Who founded the great library - which passed the knowledge on to the Romans. Who later found Jesus and pretended they never new the Earth was a sphere.
Of course, even after the church was forced to accept the Earth as a sphere sometime in the early 1500's they were still excommunicating astronomers who argued the Earth orbited the sun...
So, in short, while it was common knowledge amount scientifically educated men that the Earth was likely a sphere - it was not an accepted general fact nor by any means a proven reality. What's more, North nor South American history would teach one too much about the belief system of Europeans at the dawn of the 16th century.
Wait, did you really want to talk about theological astronomy or were you just making a point? A decade+ of catholic school combined with a decade of college can be a dangerous thing. [}:)] I'm not saying it has done any good, just that it's dangerous.
