Paradiso section 14: Beatrice asks the spirits to explain whether or not the spirits will retain their radiance after Resurrection when they rejoin their bodies. The spirits sing a hymn to the Trinity three times then the voice belonging to Solomon responds. According to Solomon, spirits will retain their radiance because it is an expression of their inner joy. All bodily organs will develop the strength to withstand the extreme brilliance. When body and soul meet again at Resurrection, the spirit will attain infinite and perfect glory. A third crown surrounds the inner two and intensifies the brilliant light surrounding Dante. The poet must look away to avoid blinding himself. Beatrice comforts Dante and when he raises his eyes again, he realizes that they have entered the Sphere of Mars. Dante observes two beams of light that intersect to form a cross. Radiant spirits perform an intricate dance while they sing something that Dante cannot comprehend within the light beams. Overcome with joy, Dante states that this experience surpasses all of the pleasures he has known. However, Dante does make it clear that he had not yet viewed the beauty of Beatrice since they had ascended to the new sphere.
Paradiso section 15: The music in the Sphere of Mars stops abruptly as the light of a spirit blazes down from the cross to approach Dante. The cordial spirit expresses his delight at seeing his blood relative. Dante's ancestor speaks about issues too profound for Dante's comprehension then urges Dante to voice his questions. Dante expresses his gratitude for the spirit's cordial greeting and asks him to identify himself. The spirit is Cacciaguida, Dante's great-great-grandfather and the father of Alighiero, the family namesake. Cacciaguida explains that when he lived in Florence the city was modest and honorable. He was baptized in Florence and went on to serve Emperor Conrad II on a crusade. He died in battle as a martyr.
Paradiso section 16: Through his conversation with Cacciaguida, Dante realizes that ancestors must continually strengthen and bring honor to their bloodline if they hope to maintain the nobility of their blood. Dante urges his great-great-grandfather to tell him when he was born and to identify the other families that lived in Florence during his time. Cacciaguida indicates that he was born around 1100 A.D. Cacciaguida, however, does not want to enumerate on the lives of his contemporaries. Instead, he tells Dante that had the Church not fought against the Empire then Florence would not have captured towns in Tuscany from which refugees flooded into Florence. In conclusion, Dante's elder lists numerous families that were thought to be noble during his time but have lost their strength now. For some of the families, Cacciaguida notes the reason for their fall from grace.
Paradiso section 17: Dante asks his forefather to tell him what his future holds. Cacciaguida tells Dante that although God sees the future, He does not interfere with man's free will. Dante's great-great-grandfather then tells Dante that his exile from Florence will be the result of a plot concerning the pope. Cacciaguida prophesies the trials and tribulations that Dante will face in exile-that he will break from his fellow exiles, that he will find refuge with della Scala of Verona, and that he will meet Can Grande della Scala who will perform great deeds that relate to Dante. Dante asks his elder if he should report what he has learned when he returns to Earth. Cacciaguida urges Dante to reveal all that he has learned even if it hurts or angers people. Cacciaguida reminds Dante to be fearless and to let his poetic mission be his guide.
Paradiso section 18: Dante turns to Beatrice while Cacciaguida concentrates on his own reflections. Overcome by his beloved's radiant beauty, Dante doubts that he can properly describe the love that he feels from her. Beatrice prompts Dante to turn his attention back to Cacciaguida when the elder's expression seems to change. Cacciaguida decides to reveal the names of other spirits that dwell in the cross from which he came: Joshua, Judas Maccabaeus, Charlemagne, Roland, William of Orange, Renouard, Godfrey of Bouillon, and Robert Guiscard. As Cacciaguida names each heroic soldier, the corresponding light in the cross shines with greater brilliance. As Dante observes Beatrice's increasing beauty, he realizes that they have moved to the Sphere of Jupiter. The souls in this realm wheel through the air like birds, flying in formation to spell a message: "Diligite iustitiam qui iudicatis terram" (Love justice, o you who judge the Earth). Only the 'M' remains as the spirits fly away and rejoin the 'M' to form first a lily then an eagle. Dante prays to understand earthly justice through divine justice then he denounces the papacy, specifically indicting Pope John XXII.