At the end of their ascent through the seven terraces of Purgatory, Dante and Virgil must cross the wall of fire which purges the lustful of their vice. It is a turning point of the narrative for this moment marks the end of the first part of Dante’s journey and the beginning of a new one: Dante is about to enter a space without sin, Earthly Paradise, where Beatrice will take on the role of guide in lieu of Virgil.
Two facts signal that the first part of the epic is ending. First, lust was the first sin to be punished in Hell and is now the last to be purged in Purgatory. Secondly, for the first time since Inf. 2, Virgil must mention Beatrice in order to help Dante overcome his fear and hesitation. At the sight of the wall, Dante is terrified. Virgil attempts to reassure him with a logical and rational speech (lines 19-32) but fails – a failure beautifully expressed in line 33, “E io pur fermo e contra coscienza” (“But, against my will, I stood stock still”). As a last resort, Virgil mentions Beatrice: “Quando mi vide star pur fermo e duro, / turbato un poco disse: ‘Or vedi, figlio: / tra Beatrice e te è questo muro’” (lines 34-36, “When he saw me stay, unmoved and obstinate, / he said, somewhat disturbed: ‘Now look, my son, / this wall stands between Beatrice and you’”). This time Virgil succeeds; Dante is convinced. To express the change of heart of his narrated self, Dante the poet recalls the myth of Pyramus and Thisbe:
Come al nome di Tisbe aperse il ciglio
Piramo in su la morte, e riguardolla,
Allor che ‘l gelso diventò vermiglio;
Così, la mia durezza fatta solla,
Mi volsi al savio duca, udendo il nome
Che ne la mente sempre mi rampolla. (lines 37-42)
[As at the name of Thisbe, though on the point of death, / Pyramus raised his lids and gazed at her, / that time the mulberry turned red, / just so, my stubbornness made pliant, I turned / to my wise leader when I heard the name / that ever blossoms in my mind…]
The symmetry between this moment and Inf. 2 is deliberate: as the name of Beatrice prompted Dante to embark on his journey, now it grants him the courage to complete it. Dante had already expressed his first change of heart in Inf. 2 with a simile: “Quali fioretti dal notturno gelo / chinati e chiusi, poi che ‘l sol li ‘mbianca, / si drizzan tutti aperti in loro stelo, / tal mi fec’ io di mia virtude stanca, / e tanto buon ardire al cor mi corse, / ch’i’ cominciai come persona franca…” (lines 127-132, “As little flowers, bent and closed / with chill of night, when the sun / lights them, stand all open on their stems, / such, in my failing strength, did I become. / And so much courage poured into my heart / that I began, as one made resolute…”). While the simile of Pur. 27 recalls that first beginning of Dante’s journey (Inf. 1-2), it simultaneously recalls Inf. 5, where the broad arc of sin taking Dante from infernal to purgatorial lust began. In fact, as Christian Moevs has pointed out, Pyramus and Thisbe are alter egos of Paolo and Francesca and of Dante and Beatrice. Pyramus and Thisbe’s story is one of lust leading to death, much like that of the infernal cognati.
In Book 4 of Metamorphoses, Ovid tells the story of Pyramus and Thisbe’s tragic love. Young lovers and neighbors, their love opposed by their families, they can only communicate with each other through a crack in the wall separating their houses. They resolve to run away together and meet by a mulberry tree. Thisbe arrives early to their meeting and encounters a lioness from which she runs away, dropping her veil. The lioness bites Thisbe’s veil, staining it with the blood of the prey it had just devoured. When Pyramus arrives, there is no trace of Thisbe except for the blood-stained veil, which Pyramus takes as a sign of his lover’s death. Overcome with despair, he decides to end his own life by falling on his sword. When Thisbe returns, she calls to Pyramus and implores him to respond: “‘Pyrame’, clamavit ‘quis te mihi casus ademit? / Pyrame, responde! Tua te, carissime, Thisbe / nominat: exaudi vultusque attolle iacentes’” (Met. 4.142-144). Upon hearing Thisbe’s name, Pyramus opens his eyes, realizes that his beloved is alive, and dies. His blood causes the flowers of the mulberry tree to turn from white to red. Thisbe also ends her life, likewise falling on Pyramus’ sword.
As discussed most thoroughly by Moevs, the reference to the myth of Pyramus and Thisbe comes with a complex net of not only classical, biblical, and Christological associations but also metaliterary ones, which invite us to consider Pur. 27 as a key moment of Dante’s poetic reflection. In the Middle Ages, the story of Pyramus and Thisbe was also associated with the critique of licentious poetry that Augustine articulated in De Ordine precisely by condemning this Ovidian myth. Moevs suggests that Dante might have been familiar with the De Ordine, where Augustine reprimands his pupil, Licentious, for dedicating too much of his time to rewriting Pyramus and Thisbe’s story and their “foul lust and poisonous flames,” which distract him from the “pure and honest love” of intellectual knowledge and beatitude. Thus, from the early Middle Ages, this Ovidian romance becomes a complex and multilayered text, and neglecting the negative Augustinian interpretation would be an oversight. In other words, Pyramus and Thisbe is to be taken as both the highest example and harshest condemnation of love poetry.
Building on Moevs’ suggestion that Dante might have known the De Ordine, I ask what it would mean to take Augustine’s text and his critique of licentious poetry as a primary source for Dante’s poetics in Pur. 27 via the reference to Pyramus and Thisbe. I have recently argued that Augustine’s De Ordine served, in fact, as a theoretical framework for Dante to formulate his linguistic and poetic theory. Thanks to Augustine’s discussion of the seven liberal arts and the notion that the invention of grammar had originally been informed by the rational rules of music (in terms of the quantities of feet, meters, and verses), Dante could distance himself from a grammatical model of linguistic and poetic analysis, more appropriate for the artificial Latin, and rethink the natural and sonorous vernacular and vernacular poetry (that is, not only its quantities and rhythm but also its sounds) directly in light of the principles of musica, one of the scientific disciplines of the artes reales or quadrivium. Thus, I would like to suggest that the reference to Pyramus and Thisbe needs to be understood as another moment of Dante’s reflection on vernacular poetry and read vis à vis Inf. 5.
In Inf. 5, Dante critiques a certain kind of poetry along the same lines as Augustine in the De Ordine. Following the model of Augustine’s De Ordine, Dante could have used Pyramus and Thisbe as a well-defined example for his circle of lust. His choice to use Paolo and Francesca instead, in my opinion, is related to Dante’s concerns about language. Paolo and Francesca, unlike the Ovidian couple, embody the vernacular, which, in the Dantean linguistic reflection, is the most dangerous language for the senses, because it is the language of sound. The vernacular is the language that resonates, learned by imitation of the nurse, and made first and foremost of sonorous vox. Dante condemns a poetry that arouses the senses by telling the story of two lovers, Paolo and Francesca (but also Lancelot and Guinevere), who clearly existed, acted, and sinned in the space of the vernacular. The same is true of Purgatorio, where, on the terrace of lust, we encounter the vernacular poets. Dante could have included Pyramus and Thisbe in the enumeration of the lustful of Inf. 5 along with Dido, Semiramis, and Tristan and Isolde. Instead, the reference that we may have expected in Inf. 5 is delayed until Pur. 27. Why? Although composed in the artificial Latin, the tale of Pyramus and Thisbe is about the sensuality of the voice. In fact, only the voice of the two lovers can overcome the barrier of the wall, and their only physical encounter, before they meet and die, is through their voices. Their vocal exchanges are true physical acts, for vox was described as a body. As the grammarian Priscian put it, “…it is evident that the voice (vox), which results from the percussion of air, is a body, since it both touches the ear and is divided into three components, that is, height, width, and length, which is a characteristic of bodies…” I suggest that the absence of any reference to the tale of Pyramus and Thisbe in Inf. 5 reveals the importance of the myth for Dante rather than a lack thereof. Much like Paolo’s and Francesca’s, Pyramus’ and Thisbe’s encounter is vocal before being corporeal, or rather it is corporeal because it is vocal. The sonorous voice is the site where seduction occurs. As champions of the sonorous language, vernacular poets (some of whom undergo purification on this terrace) wield enormous power, for they risk kindling the flames of “foul libido” (foeda libido) instead of leading to honesty and beatitude.
Thus, this reference to a Latin tale of lovers and voices is particularly significant at this point of the journey. Virgil, master of Latin poetic invention and skill (line 130: “Tratto t’ho qui con ingegno e con arte”) and yet voiceless poet whom Dante could only meet through writing (Inf. 1.62-63: “…dinanzi a li occhi mi si fu offerto / chi per lungo silenzio parea fioco”) is about to pass the torch to Beatrice, defined since Inf. 2 by her voice (Inf. 2.53-54; 56-57: “e donna mi chiamò beata e bella, / tal che di comandare io la richiesi /…/ e cominciommi a dir soave e piana, / con angelica voce in sua favella”). In other words, Dante is about to regain Beatrice’s vox, an endeavor that is only possible in the space of the sonorous language. Pur. 27 marks the end of Dante’s apprenticeship with Virgil: he has acquired ingegno and arte, now he is ready to let his senses and Beatrice’s vox suavis lead him towards contemplation (Pur. 27.131: “lo tuo piacer omai prendi per duce”). By referring to Pyramus’ and Thisbe’s tale on the ledge of the lustful, Dante is pointing both backwards, to his own infernal story of lascivious voices (Inf. 5), and forward, to the poetics of Beatrice’s “pure and honest” voice. To Dante, the sonorous voice has incredible power over the senses and, through them, the intellect. Dante is situating the voice at the core of human experience: sonorous vox, which is at home in vernacular poetry, is the cause of Paolo and Francesca’s sin and, simultaneously, of Dante’s journey to virtue; that is to say, vox is the origin of both sin and salvation. Strategically embedded in such a key moment of the journey, the tragic tale of Pyramus and Thisbe invites us to reconsider the relation between Paolo and Francesca and the one between Dante and Beatrice as profoundly vocal.
 I would like to thank Alessandro Vettori, Akash Kumar, and the anonymous reviewers for their helpful comments. A special thanks to Alex Cuadrado who generously read this note multiple times, every time providing incredibly nuanced feedback.
 For the Italian text of the Comedy, Dante Alighieri, Commedia, ed. by Anna Maria Chiavacci Leonardi, 3 vols (Milan: Mondadori, 1991-97); for the English translation, I use Dante, The Inferno, tr. by Robert Hollander and Jean Hollander (New York: Anchor Book, 2000), and Dante, Purgatorio, tr. by Robert Hollander and Jean Hollander (New York: Anchor Book, 2004).
 This is not to say that Virgil only mentions Beatrice’s name in Inf. 2 and Pur. 27, but rather that in these two cantos the sound of her name is necessary for the narrative to move forward: it is only upon hearing Beatrice’s name that Dante finds the courage to resume his journey.
 Virgil’s speech follows the principles of the rhetorical genre of deliberative speeches as laid out in Cicero’s De Inventione. In order to recognize the wall of fire as a necessary good rather than a threat, Dante needs prudentia (De Inventione, II.liii.160: “Prudentia est rerum bonarum et malarum netrarumque scientia”), which according to Cicero consists of memoria, intellegentia, and providentia (Marcus Tullius Cicero, De inventione, transl. by H. M. Hubbell, The Loeb Classical Library [Cambridge: Havard University Press, 2006]). These are the abilities to recall the past, understand the present, and foresee the future, respectively. Virgil’s speech, although brief, attempts to stimulate these faculties by recalling the precedent of Geryon, when he protected Dante (memoria: lines 22-24), inviting Dante to test the fire using his garment (intellegentia: lines 28-30), and explaining that the flames couldn’t hurt Dante even if he were to spend a thousand years inside them (providentia: lines 25-27).
 In regards to the first five cantos of Inferno, Teodolinda Barolini talks about “[the] programmatic serialization of the poem’s beginning, whereby a new beginning is accorded to each of these early cantos…” (Teodolinda Barolini, The Undivine Comedy: Detheologizing Dante [Princeton: Princeton University Press, 1992], 41). Thus, in Pur. 27 we reach the culmination of both the narrative arcs beginning in Inf. 2 and in Inf. 5.
 Christian Moevs, The Metaphysics of Dante’s “Comedy” (New York: Oxford University Press, 2005), 95.
 The wall between them is simultaneously an obstacle and channel for their communication, as Ovid’s verses emphasize: “saepe, ubi constiterant hinc Thisbe, Pyramus illinc, / inque vices fuerat captatus anhelitus oris, / ‘invide’ dicebant ‘paries, quid amantibus obstas?’ / quantum erat, ut sineres toto nos corpore iungit, / hoc si nimium est, vel ad oscula danda pateres? / nec sumus ingrati: tibi nos debere fatemur, / quod datus est verbis ad amicas transitus auris’” (Ovid, Metamorphoses, Volume I: Books 1-8, trans. Frank Justus Miller, Loeb Classical Library 42 [Cambridge: Harvard University Press, 1916], 182-184, book 4, lines 71-77).
 Ovid, Metamorphoses, 188–89: “‘O my Pyramus, what mischance has reft you from me? Pyramus! answer me. ’Tis your dearest Thisbe calling you. Oh, listen, and lift your drooping head!’”
 Moevs, The Metaphysics of Dante’s “Comedy,” 90–106. See also John Freccero, “The Sign of Satan,” MLN 80, no. 1 (1965): 11–26.
 Augustine’s language is vivid and as passionate as the poetry he is condemning: “Arripe illius foedae libidinis et incendiorum venenatorum exsecrationem, quibus miseranda illa contingunt, deinde totus attollere in laudem puri et sinceri amoris, quo animae doctae disciplinis et virtute formosae copulantur intellectui per philosophiam et non solum mortem fugiunt, verum etiam vita beatissima perfruuntur. Hic ille tacitus ac diu consideratione nutans, motato capite abscessit” (Augustinus, “De Ordine Libri II,” in Patrologia Latina, ed. Jacques-Paul Migne, vol. 32 [Paris: Garnier, 1877], I.viii.24.)
 Moevs, The Metaphysics of Dante’s “Comedy,” 105–6.
 Paolo Scartoni, “Music and Grammar. Models of Dantean Inquiry from the ‘De Vulgari Eloquentia’ to Inf. 3,” Textual Cultures 15, no. 2 (2022): 199–230.
 For Inf. 5 and the dangers of reading romances (although not in light of Augustine’s De Ordine), the most recent contribution is Alison Cornish, Believing in Dante: Truth in Fiction (Cambridge ; New York, NY: Cambridge University Press, 2022), 22–61.
 Inf. 5 reveals how the vernacular is the language of seduction, since Paolo and Francesca’s sin originates from their reading aloud the vernacular story of Lancelot and Guinevere. For what Evelyn Birge Vitz termed an “erotogenic” reading scene, see her essay “Erotic Reading in the Middle Ages: Performance and Re-Performance of Romance,” in Performing Medieval Narrative, ed. Evelyn Birge Vitz, Nancy Freeman Regalado, and Marilyn Lawrence (Cambridge ; Rochester, NY: D.S. Brewer, 2005), 73–88. In the same contribution, Vitz analyzes a reading scene from Robert de Blois’ Floris et Liriopé where the read-aloud text is Pyramus and Thisbe’s story.
 Heinrich Keil and Martin Hertz, eds., Prisciani Institutionum Grammaticarum Libri I-XII, vol. 2, Grammatici Latini (Leipzig: Teubner, 1855), 6. “…vox, quae ex aere icto constat, corpus esse ostenditur, quippe cum et tangit aurem et tripertito dividitur, quod est suum corporis, hoc est in altitudinem, latitudinem, longitudinem…” (my translation).
 Augustinus, “De Ordine Libri II,”I.viii.24.
 Scartoni, “Music and Grammar. Models of Dantean Inquiry from the ‘De Vulgari Eloquentia’ to Inf. 3,” 212–16; for Beatrice as Beatrix Loquax, see Teodolinda Barolini, Dante and the Origins of Italian Literary Culture (Fordham University Press, 2006), 360–78.