hopes & fears: Throughout your history of medieval cosmography, there are references to the “Earthly Paradise,” which map makers would often put on a map as a physical place. How seriously did people take the idea that there’s a location on Earth that is paradise, where you will go after you die? Did they think it was heaven?

Toby Lester: They’re different concepts. What Columbus was looking for, and what you’re seeing on medieval maps of the world, is not heaven as you think about it today. It was specifically the Garden of Eden as it’s described in the Bible. The basic idea was that God creates the Garden of Eden and then puts Adam and Eve in it, and then they’re thrown out of the Garden, and that begins the march of human history. Gradually those first people move across the East, and then to Mesopotamia, then they spread to Africa and ancient Greece and Rome, and eventually they make it all the way to Europe. In Columbus’s frame of mind, human history had made that march all the way from the very beginning of time and space, at the beginning of Asia, all the way to the end of Europe. And to bring things full circle and end time, you had to go around the world to the beginning.

A lot of people spent a lot of time trying to figure out the geography of the Bible. Some people still do. Part of the whole story was that it had been made inaccessible, and it was actually very hard to find. So you get stories of travelers who are clearly making things up—they travel out to the East and get close, but there are walls of fire, and it’s very high up, and four great rivers run down from it, and there’s a giant waterfall in one area, so it’s very hard to approach. Most people probably didn’t give it any thought whatsoever, just like today we don’t give a whole lot of thought to all sorts of things that we supposedly believe in. Those who did believe tended to be those writing the books and drawing the maps.