In his article on the topography of Dante's Spiritual World, Charles Allen Dinsmore writes “He [Dante] maintained that the earth is round, having a hemisphere of land, in the centre of which stands Jerusalem. The other hemisphere originally contained land; but when Lucifer, hurled from Heaven, was about to fall upon it, the soul ‘veiled itself with the sea’ and came to the other side of the globe, making a hemisphere of land and a hemisphere of water. The interior of the earth also retreated before the descending Lucifer, leaving a vast conical shaped cavity, which the seventh is subdivided into three smaller circles, the eighth into ten ditches, and the ninth into four belts. At the centre of the earth, and thus at the point farthest from God, is Lucifer, with his head and body in one hemisphere, and his legs in the other, so that when Virgil and Dante turned upon his haunch, they passed the centre of gravity and emerged from one hemisphere into the other.”

In the midst of the hemisphere of water of water stands a comical mountain, Purgatory, rising in even steps. On its summit is the terrestrial Paradise or Garden of Eden where Dante met Beatrice. According to The Divine Comedy, as the soul climbs the seven steps of Purgatory it is cleansed of the seven mortal sins, and it then ascends through the seven spheres of the Ptolemaic universe. To each of the planets is assigned one of the seven virtues, in the eighth sphere the soul receives a knowledge of spiritual truths and in the ninth, or highest, it is absorbed into the celestial mysteries.