which is the abode of God. The nine spheres are concentric, as in the standard medieval geocentric model of cosmology, which was derived from Ptolemy. The Empyrean is non-material. As with his Purgatory, the structure of Dante's Heaven is therefore of the form 9+1=10, with one of the ten regions different in nature from the other nine.

During the course of his journey, Dante meets and converses with several blessed souls.