The first person we know who realized the Earth couldn't be flat was the Greek philosopher Anaximander. Around 560 B.C., he suggested that the shape of the Earth was a cylinder. By 350 B.C., the concept of a spherical Earth was so satisfying and free of paradox that it was generally accepted by scholars even in the absence of direct proof. Eighteen more centuries would pass before there was a direct proof, in the form of Ferdinand Magellan's expedition to circumnavigate the globe.