Which celestial sphere in Paradiso contains the souls of theologians?

The sphere of the Sun in Paradiso contains the souls of theologians and other wise spirits. Dante reaches this fourth celestial sphere after passing through the Moon, Mercury, and Venus.

In the Sun, the blessed appear as brilliant lights arranged in two circling crowns. Their radiance symbolizes intellectual illumination: just as the physical Sun lights the world, these souls illuminated Christian thought through wisdom and teaching. The first crown includes Thomas Aquinas, Albertus Magnus, Gratian, Peter Lombard, Boethius, and several other philosophers and theologians.

Thomas Aquinas, a Dominican, praises St. Francis of Assisi in Canto XI. In the next canto, the Franciscan Bonaventure praises St. Dominic. This reciprocal celebration of the two religious orders expresses the harmony of Heaven, contrasting with their rivalry on Earth. Dante also places King Solomon among the wise, clarifying that Solomon’s wisdom concerned his responsibilities as a ruler.

The sphere is commonly confused with Saturn, which contains contemplatives such as Saint Benedict and Peter Damian. Mars houses warriors for the faith, Jupiter houses just rulers, and the Fixed Stars are associated with faith, hope, and love. The Sun is specifically the realm of intellectual and theological wisdom.