The now group of four continue walking on the terrace of gluttony, Virgil and Statius coupled, Dante and Forese coupled. Dante asks Forese about his sister Piccarda, and he tells him she is now in paradise. Forese goes on to point out a few other souls, the Troubadour poet Bonagiunta of Lucca, Pope Martin IV, who had an obsession with eating eel, the Ghibelline Ubaldin da la Pile, who was father to Archbishop Ruggieri (who we famously met having his brains eaten in Inferno 33), Archbishop Bonafazio, and a Marchese who was known for his drinking. But it is the poet Bonagiunta that has Dante’s interest. He asks Bonagiunta to speak to him, and the poet first mentions a woman, Gentucca, from his home town of Lucca. He goes on to ask of Dante’s new poetic style. Bonagiunta has heard of Dante writing on the nature of love, wherever it may lead. But it is now time to break away from the terrace and all the souls bound to it must move on. The three pilgrims now together again reach another tree, the tree from which Eva ate. A voice proclaims the negative examples of gluttony, the centaurs, known for their drunkenness, and the Hebrew soldiers who were excluded from Gideon’s army because they drank like dogs. Finally they meet the angel of this terrace who wipes away the sixth “p” off Dante’s forehead.
The three poets now move on toward the next terrace but in the in-between discuss the nature of the body and soul. Dante asks how a soul devoid of body could grow emaciated in that terrace of the gluttony. Virgil starts to answer but turns to Statius to provide it. Statius, rather than answer directly, expounds on the entire process of how the body and soul are formed. He explains how the essence of the male blood is formed and mixed with the essence of the female blood to form a new being with its own animal soul. At this point God breathes into the being an additional soul, the spirit, which blends with what is there to form a single soul. When the being dies, he carries both elements of the soul, but the physical one can undergo transformation through the purgatorial penances while the spirit waits for the perfected physical soul to reconstitute herself. The finally come to the last terrace where a wall of fire stands before them with just a tiny edge for the ledge. They hear a hymn of clemency being sung and the penitents crying out Virgin Mary's words, "I know not man" and of the Roman goddess of chastity, Diana. They have come to the terrace of lust.
Walking single along the edge, Virgil cautions Dante to be careful. The sun, now low on the horizon, cast Dante's shadow onto the wall of fire making the flames change shade. The penitents walking by are amazed by this and one particular soul asks Dante how this could be. Before Dante responds he notices one group of penitents passing another group, each giving a platonic kiss to a passing person. After each kiss, one group would shout out "Sodom and Gomorrah" and the other would shout out Pasiphae, the wife of King Minos who lusted after a bull. The souls gather around Dante to hear him explain, and he tells them that he is still alive. Dante asks of the significance of the groups kissing, and the soul who first approached him again speaks. He explains that the group shouting "Sodom" are homosexuals, and he and the others are heterosexuals, both groups trying to cure themselves of their beastly sexual appetites. The soul introduces himself as Guido Guinzzelli. Dante is astonished because he knew of Guinizzelli's poetry, and considers him another father figure. Guinizzelli humbly points out another soul close by, who was even a "better craftsman," Arnaut Daniel, the Provencal Troubadour who wrote in his mother tongue. As Guinizzelli fades into the fire, Arnaut steps up and for the only time in the entire Divine Comedy speaks in a language other than Italian and asks in his Provencal to pray for him. He too then fades into the fire.
The pilgrims reach an end where they can go no more. In front was a wall of flame. An angel could be seen inside the fire and invites them to enter. All that go on must be “bitten” by this fire. But Dante freezes. He is in fear the fire will consume him like the burning of bodies he had once seen. Virgil implores him. The fire may torment but it will not cause death. He implores Dante to test it with his hand, with his sleeve, but no amount of reason can undo the panic Dante feels. Then Virgil appeals to his desire to see Beatrice, who will be on the other side of the flame. With the name of Beatrice, Dante begins to soften. Virgil then steps in, and Dante follows, and Virgil to keep Dante encouraged says, “I can almost see her eyes.” With hymns being sung, the dazzling light of the fire blinds Dante. When they come out, the night has set and they settle down on a step to sleep. He dreams of a woman who tells him she is Leah and that her sister Rachel never leaves a mirror where she is fixated on her own eyes. When they awake, they continue to the very top most step of purgatory, and there Virgil tells him he can go no further. Dante can stay there until the one with the “fair eyes” arrives.
Dante now on top of the purgatorial mountain, where a forest is before him, wanders about exploring. The softest, gentlest breeze caresses him, and about him small birds sing "songs of joy." Lost in the forest, echoing that very first canto from Inferno where he had lost his way, he stumbles upon a stream with the purest water he has ever seen. Across the bank and among the blossoms, he notices a pretty lady singing. He calls out to her to come closer so he can make out her song. The lady, who we will eventually learn her name as Matelda, turns towards him and approaches the stream so that now Dante can understand her song. She says she is there to answer all his questions, and she goes on to explain how this was the earthly paradise given to Adam and Eve. Matelda explains the breeze comes from heaven above, the abundant verdure, and of the fecundity of the holy ground. She reveals that there are two rivers, this one beside them called Lethe, and has the power to wipe away memories of sin, and another on the other side of the wood, Eunoe, that has the power to return all memories of good to consciousness.