Although Renaissance humanist geographical writers did not adhere strictly to the tenets of any one ancient school of philosophy, they were strongly influenced by Neoplatonism, and in particular by one Platonic dialogue: the Timaeus. In the first half of the sixteenth century, when the Americas were less completely absorbed into European geographical consciousness, there are fewer references to Plato, but in the latter half of the century writers increasingly made use of his work to interpret the nature and structure of the world. It is not surprising that in a society where people were scouring the classics to interpret better the geography of the New World, many humanist trained writers from all over Europe, including Ramusio, Hakluyt, Gomara, and Ortelius, came to equate the New World with Plato's Atlantis, first mentioned in the Timaeus. Yet the use of Plato went beyond mere reference to the Atlantis myth. Particularly when writing about the western hemisphere, many writers used Platonic ideas of harmonia mundi to explain the nature of the world, and in particular the relationship between the old oikoumene and the newly discovered continent. This chapter will examine the way in which sixteenth-century descriptive geographers reinterpreted the ideas of Atlantis, harmonia mundi, and the ‘best possible world’ to understand the New World, and its relationship to the Old.

For many of those Renaissance geographers seeking an understanding of the nature of the New World, Plato's Atlantis myth provided a source of information. Plato developed the story of Atlantis in his dialogues, the Timaeus and the Critias. The Timaeus was particularly influential since it was the only Platonic dialogue read throughout the Middle Ages. In the Atlantic section, Plato tells the story of how, 9000 years earlier, soldiers from a large island called Atlantis – lying in the Atlantic to the west of the Pillars of Hercules – invaded Europe, Africa and Asia. A coalition of Greek armies resisted, but ultimately all drifted away, except the Athenians who were left alone to fight the invaders. The Athenians successfully drove them out of all their conquered territories and pursued them back to Atlantis, but at that time there was a sudden earthquake, in which the entire island (and everyone in it, including the pursuing Athenians) was swallowed up by the sea.