Magellan and the construction of knowledge

I have been reading "Over the Edge of the World: Magellan's Terrifying Circumnavigation of the Globe" by Laurence Bergreen. The book is an entry into a world distant in time and place, and a good read. In the context of this blog however, I want to point out one of the book's central premises.

Magellan's voyage around the world, during which he died, took place between 1519 and 1522. According to Bergreen, in Magellan's time -- the Age of Exploration -- there was a significant separation between the maps of:

• cosmologists who where academics seeking to describe the earth (and the heavens) through the application of mathematics and the study of sources believed to be authentic at the time, and dating back to the ancient Greeks and Romans.
• pilots, whose "portolan" charts were based on the actual observations made by ships crews, and especially by the European explorers who were literally sailing into uncharted waters.

The cosmologists were gentlemen and the pilots were working class. Thus there was a reluctance of the cosmologists to give credence to the maps of pilots over those of ancient philosophers whose writings were rediscovered during the renaissance.

Magellan is described as a gentleman who knew enough to distrust the maps and globes produced by the cosmologists, who was still deeply affected by their ideas that the world was round and that the Pacific was a relatively small body of water that would be easily navigated. He was also an experienced sailor, who knew the value of pilot's charts. He is also described as one of the first of the breed of modern men who sought knowledge through direct observation.

His circumnavigation of the globe provided a direct observation of the shape and size of the earth, and forever changed cosmology.

Source: The Great Explorers: Ferdinand Magellan

I guess we are all influenced by the mythology promulgated by the authoritative academics of our times, even as we depend on the knowledge accumulated by working men through their observations. Magellan was one of the pioneers that made modern science possible.