Ambrosius Macrobius

Ambrosius Macrobius was a Roman philosopher and writer of the fifth century who is best-known for his Saturnalia, a dialogue in seven books which includes a literary evaluation of Virgil as well as valuable quotations from other writers.  Also contained in Saturnalia is the text, with commentary, of Cicero's Dream of Scipio, which was popular in the Middle Ages and influenced Chaucer.  Macrobius was among the first to hold the idea of a spherical earth with northern and southern hemispheres divided by an equatorial ocean.  He believed in ocean currents and also identified 'frigid' and 'temperate' zones.  He was a follower of the Neoplatonists and eagerly blended Plato's ideas with theosophy.