" Ptolemy's massive compendium of mathematical and astronomical calculations had been rediscovered in 1410, after centuries of neglect. The revival of classical learning pushed aside medieval notions of the world based on a literal--yet magical--interpretation of the Bible, but even though Ptolemy's rigorous approach to mathematics was more sophisticated than monkish fantasies of the cosmos, his depiction of the globe contained significant gaps and errors. Following Ptolemy's example, European cosmologists disregarded the Pacific Ocean, which covers a third of the world's surface, from their maps, and they presented incomplete renditions of the American continent based on reports and rumors rather than direct observations. Ptolemy's omissions inadvertently encouraged exploration because he made the world seem smaller and more navigable than it really was. If he had correctly estimated the size of the world, the Age of Discovery might have never ocurred. "

― Laurence Bergreen , Over the Edge of the World: Magellan's Terrifying Circumnavigation of the Globe