The uniquely self-conscious opening of this canto, featuring the only explicit numeration of a canto in the poem, has caused a certain puzzlement and even consternation. One discussant, H. D. Austin, has argued that its prosaic superfluity recommends that future editors either excise it from the poem, as an addition by an over-enthusiastic scribe, or at least print it in square brackets (“The Submerged [Inf., XX, 3],” Romanic Review 23 [1932]), pp. 39-40. Its self-consciousness and difficulty, one might argue in rejoinder, are precisely signs of Dantean authorship.

The opening line (which a student, Simina Farcasiu [Princeton '83] some years ago suggested was a redoing of the first verse of Ovid's Metamorphoses: 'In nova fert animus mutatas dicere formas / corpora' [My mind inclines to tell of bodies changed into new forms]) portrays a poet who only unwillingly commits himself to the difficult task he now must assume. Many of the words of this first tercet have received close critical attention. Nova has either the sense (or both senses, as our translation would indicate) of 'new' or 'strange' (see D'Ovidio [“Esposizione del canto XX dell'Inferno,” in his Nuovo volume di studi danteschi (Caserta-Rome: A. P. E., 1926), p. 318]). Matera is, as Chiavacci Leonardi says (Inferno, con il commento di A. M. C. L. [Milan: Mondadori, 1991]), p. 599, a 'technical term,' one used to denote the subject that a writer chooses to treat. Canto is here used for the first time (it will be used again only at Inf. XXXIII.90, Par. V.16, and Par. V.139) to indicate a part of the poem; as Baranski (“The Poetics of Meter: Terza rima, 'canto,' 'canzon,' 'cantica,'” in Dante Now: Current Trends in Dante Studies, ed. Theodore J. Cachey, Jr. [Notre Dame: University of Notre Dame Press, 1995]), pp. 3-4, has pointed out, the early commentators found this term strange, rendering it with Latin or Italian words for 'chapter' or 'book.' Canzone is a still more troubling choice of word (it is used twice more, Purg. XXXI.134, Purg. XXXII.90); in De vulgari eloquentia (e.g., II.viii.2-9) it is the word (cantio in Dante's Latin) that describes the lofty vernacular ode that Dante presents (with himself as most successful practitioner of the form) as the height of poetic eloquence in the mother tongue, and thus 'tragic' in tone, because it is like the lofty style of the classical poets. Is Dante suggesting that Inferno is tragic? For some thoughts along this line see Hollander, “The Tragedy of Divination in Inferno XX,” in Studies in Dante (Ravenna: Longo, 1980), pp. 137-40. It is only in Purg. XXXIII.140 that he will finally give a part of the poem the name it now enjoys: cantica, with its religious (resonance of Solomon's Canticle of Canticles [see Lino Pertile, “Canto-cantica-Comedía e l'Epistola a Cangrande,” Lectura Dantis (virginiana) 9 (Fall, 1991), pp. 107-8]) and 'comic' overtones. And finally there is the apparently strikingly inexact word sommersi, which has seemed to many commentators wrong, since the damned are not submerged in water but buried under earth. Marino Barchiesi (“Il Testo e il Tempo,” Il Verri, ser. V, no. 4 [December 1973], p. 85) resolved this problem by finding a probable source in the Aeneid (VI.267), where Virgil asks the gods for permission 'pandere res alta terra et caligine mersas' (to reveal things immersed deep in earth and darkness).

If the opening tercet causes this much difficulty, what follows will often be at least as challenging. One of the most interesting and provocative studies of the canto remains Parodi's essay (E.G. Parodi, “La critica della poesia classica nel ventesimo canto dell'Inferno,” Atene e Roma 11 [1908], pp.183-95, 237-50). It is a canto that is still today renowned for its problematic nature.

The first description of the diviners insists upon their silence and their misery, expressed by tears, the only form of expression allowed them, given the fact that their necks are twisted, thus cutting off the possibility of speech. We are probably meant to reflect on the fact that their voices, announcing their false prescriptions were the instruments of their deception of their clients/victims.

Hollander has suggested (“The Tragedy of Divination in Inferno XX,” in Studies in Dante [Ravenna: Longo, 1980], p. 141) that the image of the twisted necks of the diviners, with the resultant loss of the capacity of speech, may have been suggested by a text in Lucan (Phars. V.197), in which Apollo closes off the throat of a prophetess (Phemonoe) before she can reveal the rest of a dire prophecy, thus depriving her Roman listener of news of his unhappy destiny: 'Cetera suppressit faucesque obstruxit Apollo' (Apollo closed her throat and suppressed the rest of her speech).

The backward-looking diviners suffer this contrapasso for having looked, with wrongful intent, into the future. Biblical references have seemed apt to an occasional commentator. Pietro di Dante (Pietro2, comm. to vv. 10-15) adduces Isaiah 44:25: '[I am the Lord] That frustrates the tokens of the liars, and makes diviners mad; that turns wise men backward, and makes their knowledge foolish' ([Ego sum Dominus] Irrita faciens signa divinorum, / Et ariolos in furorem vertens; / Convertens sapientes retrorsum, / Et scientiam eorum stultam faciens). Rossetti (comm. to vv. 10-18) adverts to another biblical passage (Micah 3:6-7): 'Therefore night shall be unto you, that you shall not have a vision; it shall be dark unto you, that you shall not divine; and the sun shall go down over the prophets, and the day shall be dark over them. Then shall the seers be ashamed, and the diviners confounded' (Propterea nox vobis pro visione erit, / Et tenebrae vobis pro divinatione, / Et occumbet sol super prophetas, / Et obtenebrabitur super eos dies. / Et confundentur qui vident visiones, / Et confundentur divini).

The first tercet of this fourth address to the reader in this cantica (see note to Inf. VIII.94-96) is generally understood as indicating that, given the sad sight he must behold, Dante is excusing himself from blame for weeping. Benvenuto da Imola, however, has a differing view (and says that 'this subtle fiction is poorly understood by many others'). According to him (comm. to these verses), Dante's tears reveal his guilty feelings about his own involvement in astrological prediction and that 'as a result he presents himself as weeping out of compassion for others, and for himself because of his own errors' (Ideo bene fingit se nunc ita plorare compatiens aliis et sibi de errore suo). It is possible to read the passage in an even harsher light. If the reader is to 'gather fruit' from reading this passage, is it not likely that its point is that Dante was wrong to weep for these creatures? What he feels is sadness at the human figure rendered so contorted, forgetting the reason for the (entirely just) punishment. And the language of verse 21 allows a different understanding (and translation) than it generally receives: how Dante might well have refrained from weeping, but failed to behave as would have been only appropriate.

For discussion of two other passages in the poem (Inf. V.70-72; Inf. XIII.82-84) in which Dante feels pity for the sinners that is evidently not sanctioned, see Hollander, “The Tragedy of Divination in Inferno XX,” in Studies in Dante (Ravenna: Longo, 1980), p. 168n.

Dante weeps and thereby earns Virgil's rebuke (which commentators since Tommaseo [comm. to these lines] have related to the words that Jesus directed to Peter and the other apostles, slow to take his meaning, found in [Matthew 15:16]: 'Adhuc et vos sine intellectu estis?' [Are you also even yet without understanding?]). A question that has exercised many readers is whether the protagonist already knows that those punished here are the diviners. While some, like Ettore Caccia (“Canto XX,” in “Inferno”: Lectura Dantis Scaligera [Florence: Le Monnier, 1967], p. 695) and Antonino Pagliaro (Ulisse: ricerche semantiche sulla “Divina Commedia” [Messina-Florence: D'Anna, 1967], p. 611), argue that Dante weeps only at the piteous condition of the contorted human body, and not for the lot of the diviners, others, like Marino Barchiesi (“Catarsi classica e 'medicina' dantesca, Dal canto XX dell'Inferno,” Letture classensi 4 [1973], p. 62), reply that such distinction-making is over-subtle. Indeed, the whole context of the canto would make it seem necessary that Virgil's rebuke is not aimed at so wide a target, but rather at Dante's failure to react adversely to the diviners. The more general reading is also less capable of explaining the final image of the preceding tercet, in which the tears that move Dante to fellow-feeling are seen running down into the clefts of the sinners' buttocks. It is no wonder that, even at its inception, he was so unhappy at the prospect of writing out this canto (XX.1): it contains a pointed reminder of his failure to respond correctly to the sin of divination.

Perhaps the tercet in the canto that has caused the most debate. Where is 'here' (qui)? Who is indicated by the the first 'who' (chi)? And what does the last verse of the tercet mean? In response to the first two questions, Hollander has made the following observations (“The Tragedy of Divination in Inferno XX,” in Studies in Dante [Ravenna: Longo, 1980], p. 147), dividing the most plausible series of answers into two groups: '(1) If Dante weeps for lost humanity in general, qui refers to hell in general and chi almost certainly refers to Dante. (2) If Dante weeps for the diviners in particular, qui refers to this bolgia and chi almost certainly applies to the diviners.' Carlo Steiner (comm. to vv. 29-30) argues that it seems logically inconsistent for Virgil to call Dante 'witless' at v. 27 and 'impious' at v. 29, as stupidity and impiety are some stages distant one from another. For another reason, based in Lucan's text, to accept the second hypothesis, see Sonia Gentili, “La necromanzia di Eritone da Lucano a Dante,” in Dante e il “locus inferni”: Creazione letteraria e tradizione interpretativa, ed. Simona Foà e Sonia Gentili (Rome: Bulzoni, 2000 [= Studi (e testi) italiani 4 (1999)]), pp. 35-38.

As for the complicated philological problem regarding the exact reading of verse 30, this writer, along with many another, accepts the arguments of Petrocchi (La Commedia secondo l'antica vulgata, pp. 181-82) for the reading 'passion comporta' (and not 'compassion porta' or 'passïon porta'). But what does this mean literally? A passage in Monarchia (I.xi.6) may be of assistance. There Dante says those who attempt to stir up a judge's passions are to be censured ('repelluntur qui iudicem passionare conantur'); in our passage a similar concept has a rather different formulation, since the Judge in this case is God himself. Thus, in this reading, the sin of the diviners is to believe (or to represent) that God is like us, that is, that He is subject to emotions in his response to human desiring; it is these emotions that diviners claim (fraudulently) to be able to decipher: e.g., if you sacrifice a living creature that you love, God will be predisposed to help you. (For a fuller exposition, based on texts in Statius and St. Augustine, see Hollander, “The Tragedy of Divination,” pp. 147-57, citing, for Augustine, the earlier discussions of Lorenzo Filomusi Guelfi, Nuovi studi su Dante [Città di Castello: Lapi, 1911], pp. 192-95; and now see Valter Puccetti [“La galleria fisiognomica del canto XX dell'Inferno,” Filologia e critica 19 (1994)], pp. 199-206). This seems a consistent reading, one that keeps all strands of the passage clearly in sight. Is it 'correct'? That is harder to say. For brief descriptions of a good half-dozen competing interpretations of the sin of the diviners see Ettore Caccia (“Canto XX,” in “Inferno”: Lectura Dantis Scaligera [Florence: Le Monnier, 1967]), pp. 688-90. It should be remembered that the attempt to assay the future, while potentially sinful, is not in itself fraudulent. Those who argue that it is the main thrust of Dante's view of divination should reconsider; it is the representation of untruth about the future that is blameworthy as fraudulent, for this involves a misrepresentation of the nature of God's judgment.

In Canto XI Virgil has two continuous speeches of some length, vv. 15-66 and vv. 76-115. We are here involved in Virgil's longest single speech in the poem, vv. 27-99. Having warned Dante against the sin of divination, he now proceeds to identify its exemplars, beginning with five classical diviners. The first of these derives from Statius. Amphiaraus was one of the seven kings who joined in the assault, on behalf of Oedipus's son Polynices, against Eteocles, the other son of Oedipus, who first came to the rulership of Thebes in the wake of their father's death and who refused to step down in favor of his brother, as had been agreed, at the end of his appointed year. Amphiaraus, by divination, saw that he would perish in the war against Thebes and secreted himself from the allies. His hiding place was betrayed by his wife, Eriphyle, bribed to do so by Polynices with the necklace of Harmonia. It was thus that Amphiaraus enjoined their son to put his mother to death (see Purg. XII.49-51 [and note] and Par. IV.103-105). This warrior-diviner is the first hero to die in the war, a figure represented by Statius as brave and noble in the face of death. Indeed, the incidents referred to here are a somewhat reinvented version of the narrative found in Statius (Thebaid VII.690-823; VIII.1-210). For Dante's willful distortions of the story of this augur, who is portrayed with great sympathy by Statius, see Hollander, “The Tragedy of Divination in Inferno XX,” in Studies in Dante (Ravenna: Longo, 1980), pp. 170-73.

Dante derives his portrait of Tiresias, the Theban soothsayer, from Ovid (Metam. III.316-338). For a study of Dante's recasting of this essentially positive presentation of Tiresias, making him a repulsive figure rather than the truthful and blameless seer he is in Ovid's text, with particular attention to the verga, or magic wand, that Dante contrives for him, thus associating him with Circe and Mercury, see Hollander, “The Tragedy of Divination in Inferno XX,” in Studies in Dante (Ravenna: Longo, 1980), pp. 173-84.

Dante found Aruns in Lucan (Phars. I.584-638), discovering, in the diseased innards of a sacrificial bull, the foul outcome of the civil war (in Lucan's view, surely the victory of Caesar over Cato). Castelvetro (comm. to these verses) points out that, in Lucan's text, Aruns does not dwell in a cave but within the walls of Luni and that, furthermore, he was not an astrologer (as Dante implies) but used other means to develop his soothsaying (e.g., studying the flight of birds, the innards of animals, the course of the thunderbolt). It is further notable that Dante does not refer to Erichtho, the diviner par excellence in Lucan's poem (see Inf. IX.23), but to the less egregious Aruns. See Hollander, “The Tragedy of Divination in Inferno XX,” in Studies in Dante (Ravenna: Longo, 1980), pp. 184-88.

Compared with the violence done to classical texts in the preceding three examples (Amphiaraus, Tiresias, and Aruns), that done to Virgil's tale of Manto is even more remarkable. Even her hair seems to belong to another, whether the uncombed locks of frenetic Erichtho ('inpexis... comis' – Phars. VI.518), as Benvenuto da Imola suggested (comm. to vv. 52-54), or those of the Sibyl (perhaps the 'source' for Lucan's witch's hair), 'non comptae... comes' (Aen. VI.48), as noted by Grabher (comm. to vv. 52-57). Since the Roman poet, as surely Dante realized, had deliberately associated his birthplace (Pietola, then probably known as Andes, near Mantua) with Manto, so as to make himself, like her, a vates, or prophet (see the study by Marie Desport [L'Incantation virgilienne: Virgile et Orphée (Bordeaux: Delmas, 1952)]), Dante now makes his maestro ed autore recant the fiction that he himself had devised. (Virgil's commentators themselves had wondered how the Greek Manto could have come to Italy in order to found her city, since Virgil's poem is the only text to contain this claim.)

One of the lasting problems left by this canto is its eventual contradiction of Dante's placement of Manto in Limbo (Purg. XXII.113}, where Virgil tells Statius that various of the characters of whom the later poet wrote are found in that zone of the afterworld. Previous writers had resorted to various hypotheses, none particularly satisfying, in order to explain how Dante could have forgotten what he had said about Manto here when he wrote the later passage, or that, with equal failure to satisfy, 'the daughter of Tiresias' of Purgatorio XXII was someone other than Manto, or even that the original text read something other than 'la figlia di Tiresia.' In the face of this problematic passage, some may choose to accept the view of Giancarlo Rati (“La pietà negata [Il canto XX dell'Inferno],” in his La pietà negata: letture e contributi danteschi [Rome: Bulzoni, 2000 (1994)]), pp. 60-61, that here there is no willful correction of Virgil's tale of Manto, merely a tactic to establish how the truly mantic Virgil came by his gifts. On the other hand, two Americans have argued independently that the apparent contradiction is intentional, and is based on Dante's willful insistence that the Manto portrayed by Virgil was indeed a diviner, while the same character portrayed by Statius was not (she is rather the dutiful daughter of Tiresias, helping with the chores, as it were). See Richard Kay (“Dante's Double Damnation of Manto,” Res publica litterarum 1 [1978], pp. 113-28.) and Robert Hollander (“The Tragedy of Divination in Inferno XX,” in Studies in Dante [Ravenna: Longo, 1980], pp. 205-13). Kay also argues, less convincingly, that Dante thought of Virgil's Manto as historical and of Statius's character as fictive, thus further excusing the bilocation. Emilio Pasquini (Dante e le figure del vero: La fabbrica della “Commedia” [Milan: Bruno Mondadori, 2001], p. 14), having accepted Padoan's disagreements with Petrocchi about the dating of the composition of the various parts of the poem, believes that the contradiction, apparently the result of Dante's having had a change of heart about Manto, is merely the result of the earlier dissemination of Inferno XX. Yet Dante surely was not likely to have forgotten the large and agitated attention he had given to Manto, even at the distance of some years; nor would he have deliberately contradicted himself with ulterior purpose. It is not material that he wrote the two passages at any particular time so long as he wrote Inferno XX before he wrote Purgatorio XXII. For a reassessment of the entire question, with a new hypothesis accounting for Dante's deliberate 'self-contradiction,' see Palma di Cesnola, Questioni dantesche (Ravenna: Longo, 2003), pp. 71-140.

With risible understatement, the poet has Virgil ask for a little of the protagonist's time (his digression will continue until verse 99, occupying fully fourteen terzine). This passage begins by tacitly acknowledging the utter fictiveness of this account, since we have no source for what happened to Manto after Tiresias's death (and the conquest of Thebes by Creon). Dante puts, into the mouth of Virgil, an account of her voyage into Italy. As is the case for that undertaken by Ulysses in Canto XXVI, there is no known source for this one, either.

Maurizio Palma di Cesnola (“Teseo, Creonte e la morte di Tiresia [Inf. XX 58-59],” L'Alighieri 15 [2000], pp. 117-25) points out that, after Creon's brief (unhappy but 'legitimate' – since he was Jocasta's brother) reign, it was Theseus who made Thebes 'subject,' when he was called in to end the tyranny of Creon by the Thebans, and thus Manto left after that event and (we must presume) after the consequent death of her father. Beginning with Scartazzini (1900), modern commentators fall into this error, which, as Palma points out, could have been avoided by a glance at Dante's source in Statius (Thebaid XII.752-781), where it is clear that, after roughly a week of Creon's reign, the Thebans called on Theseus to free them of him. This he did, killing Creon and seizing the city. To their dismay, the city then remained subject to him, an Athenian, a foreigner.

We turn our attention from the story of Manto in order to examine the landscape of Italy, to which she will repair in her wanderings. Benaco is now known as Lake Garda.

The fresh waters of northern Italy, entering into Garda, with its island that might serve for Christian services if the various bishops of its neighboring dioceses were to gather there, since a chapel on the island was subject to the jurisdiction of all three of them, will be seen to contrast with the muddy waters surrounding Manto's adoptive homeland once we arrive there. For discussion of the meaning of these geographical references see Ettore Caccia, “L'accenno di Dante a Garda e i versi 67-69 nel canto XX dell'Inferno,” in Dante e la cultura veneta, ed. V. Branca and G. Padoan (Florence: Olschki, 1966), pp. 307-25.

The fortress at Peschiera, under the control of the Scaliger family of Verona, with whom Dante was on good terms by the time he was writing the Comedy, is seen as strong enough to hold off attacks from the cities of Brescia or Bergamo.

Leaving Benaco (Garda), the waters that began in the mountains to the north now head south (in the Mincio) and finally, after reaching Governolo, east (in the Po – in which they finally reach the [Adriatic] sea).

Here the attention of Dante turns back to a spot that the waters reach before they attain Governolo, the untilled, swampy land that will become the site of Mantua.

Finally here is Manto. She is described as 'vergine cruda' (cruel virgin [in the sense that she does not like the company of men]), a phrase that may reflect Statius's description of her (Thebaid IV.463) as 'innuba Manto' and/or Dante's description of that other diviner, Erichtho, who is 'Eritón cruda' at Inferno IX.23. Here she practiced her divinatory arts with her servants and died. Those who had fled her fearsome presence returned after her death and built Virgil's city upon her bones, giving it her name, but not her divinatory capacity. What is at first shocking about this account is that it contradicts what we find in the Aeneid, where (Aen. X.198-203) we learn that the city was founded by Ocnus, the son of Manto. In other words, Dante has excised (indeed, has forced Virgil himself to excise) Ocnus. For if Manto had had progeny, as she did according to Virgil, then her mantic ability might have been passed on to others – the claim that Virgil was evidently himself bent upon making in his poem (see, again, the study by Marie Desport [L'Incantation virgilienne: Virgile et Orphée (Bordeaux: Delmas, 1952)]) only to be forced to recant it here in Dante's. It is an extraordinary moment.

Dante's reference to a late-thirteenth-century political disaster in Mantua probably seems gratuitous to the modern reader. Given the poet's concern with the condition of his own Florence, however, we can appreciate his interest in the dramatic events resulting from when Guelph leader of Mantua, the Count of Casolodi, allowed himself to be tricked by the Ghibelline Pinamonte Bonacolsi, who apparently convinced him to expel many of the nobles in order to mollify the populace, angered by his having come from Brescia to rule in 1272. Foolishly exiling even members of his own party, he was in time bereft of supporters; in 1291 Pinamonte led a popular revolt that sent him into exile and killed the remaining noble families. The tercet offered Dante a moment's bitter reflection upon his own condition as exiled Guelph, brought about by the similar folly of his fellow citizens.

Capping his (to us absurd yet amusing) contradiction of the details of the founding of Mantua published in his own poem, Virgil now gets Dante to swear that he will regard only the current version of that history as truthful, and that he will consider any other version, i.e., the Roman poet's own, as nothing other than a lie. The protagonist dutifully assents. Thus is Virgil made to remove the stain of divination from his poem and from himself. The result is eventually quite different from what the tactic might have been intended to secure, i.e., Virgil's poem is seen precisely as associated with this fault. See Teodolinda Barolini (“Canto XX: True and False See-ers,” in Lectura Dantis: “Inferno”, ed. A. Mandelbaum, A. Oldcorn, C. Ross [Berkeley: University of California Press, 1998]), pp. 283-84.

Not even in Sinon's lying account of these events (Aen. II.114-119), to which the text refers, is Eurypylus said to be an augur: the message that he brings back from Apollo's shrine is then interpreted by Calchas, the 'true' augur in the Aeneid, to mean that Sinon must be sacrificed. We should reflect that Dante must have realized that none of what Sinon says is truthful. Yet he nonetheless uses this material in order to concoct his own still more inauthentic version of events. See Hollander, “The Tragedy of Divination in Inferno XX,” in Studies in Dante (Ravenna: Longo, 1980), pp. 200-3.

The phrase with which Virgil indicates the Aeneid, 'l'alta mia tragedìa,' has caused only some debate, as most commentators believe that, for Dante, with regard to its plot, Virgil's epic was a 'comedy' because it begins in difficulty (the shipwreck that initiates the action) and ends in happiness (the impending marriage of Aeneas and Lavinia; the impending foundation of Rome). Its style, on the other hand, is generally seen as lofty, and thus, in Dante's understanding of such things, 'tragic' (see, for example, Inf. XXVI.82, where Virgil also refers to epic writing as being in the high, or tragic style: 'quando nel mondo gli alti versi scrissi' [when, in the world, I wrote my lofty verses]). For an attack on the usual understanding, beginning with the view that Virgil's phrase would then be pleonastic ('l'alta mia tragedìa' would need to be understood as having the sense of 'my lofty high poem,' twice referring to the stylistic level of the work), and arguing that both for a few early commentators and in Dante's own views the plot of the Aeneid is indeed tragic, see Hollander, “The Tragedy of Divination,” pp. 214-18; Il Virgilio dantesco: tragedia nella “Commedia” (Florence: Olschki, 1983), pp. 130-34; Dante's Epistle to Cangrande (Ann Arbor: University of Michigan Press, 1993), pp. 19, 62-66. According to this reading, the meaning of Virgil's phrase is that his poem is lofty in style and unhappy at its conclusion, the death of Turnus at the hands of Aeneas, who gives over the ideal of clemency when he kills his enemy. For sharp disagreement with this view, see David Scott Wilson-Okamura, “Lavinia and Beatrice: The Second Half of the Aeneid in the Middle Ages,” Dante Studies 119 (2001), pp. 103-24. However, for a rare Italian understanding that, for Dante, the Aeneid was a tragedy (if one based on different principles of observation), see Giorgio Agamben, “Comedy,” in his The End of the Poem: Studies in Poetics, tr. Daniel Heller-Roazen (Stanford: Stanford University Press, 1999 [1978]), pp. 4-6.

Michael Scot was indeed a Scotsman (lived ca. 1175-1235). He studied at Oxford and Paris, eventually joining the court of Frederick II at Palermo. For Frederick he translated some of Aristotle from Arabic, a language he had studied in Spain. He himself wrote mainly on the occult sciences (e.g., alchemy, astrology) and achieved a large European following. For a description of his Liber astronomicus see Lynn Thorndike, A History of Magic and Experimental Science (New York: Macmillan, 1923), vol. 2, pp. 826-35.

Guido Bonatti (late thirteenth century) lived at Forlì and devoted himself to the study of astrology, probably serving in the capacity of soothsayer to Guido da Montefeltro (Inf. XXVII). Bringing this unseemly 'parade' of diviners to a point near its close (only the nameless female cohort of sorceresses awaits us), Benvenuto of Parma, a cobbler nick-named 'Asdente' ('toothless'), did his predicting in the late thirteenth century and was known, perhaps by reputation alone, to Dante, who ridicules him (Conv. IV.xvi.6).

Dante's eight astrologers have moved from classical through thirteenth-century exemplars, the recent ones in descending nobility and literacy. His list now declines to an anonymous plurality of commonfolk, women who practice witchcraft through brewing magic potions and making images of their clients' enemies. For a detailed study of Dante and magic see Simon Gilson, “Medieval Magical Lore and Dante's Commedia,” Dante Studies 119 (2001), pp. 27-66.

The moon is setting over the point that demarcates the border of the hemisphere of land (with its center, in the medieval and moralized cartographical conception, at Jerusalem) and that of water. The moon is setting in the ocean west of Seville and the sun is about to rise, from the perspective of one watching at Jerusalem. Medieval legend has it that what is often referred to in our time as 'the man in the moon' was the image of Cain carrying a bundle of thorns. For a study of this tradition see Stanislao Prato's book, Caino e le spine secondo Dante e la tradizione popolare (Ancona: Garzanti, 1881). For the astronomical and cartographical ramifications of the passage see Corrado Gizzi, L'astronomia nel poema sacro (Naples: Loffredo, 1974), vol. 2, pp. 113-36.

Once again (see, for example, Inf. XVI.106-108) Dante adds a detail to an earlier scene in the poem, the prologue, the action of which takes place on this earth. There is no mention of the moon in the first Canto. It is also not possible that Virgil means yesterday night, as some propose, for Dante and Virgil were then already in hell, having begun their descent on Friday evening after Dante spent his night in the wood on Thursday: '“yesternight,” i.e. the night before last, it being now early morning' is the explanation offered in Tozer's gloss on this verse (comm. to verse 127).

Having proscribed the word introcque from the illustrious vernacular in De vulgari eloquentia (I.xiii.2), Dante here employs it. It is a Latinism (derived from inter hoc) and means, roughly, 'meanwhile.' That is how Dante uses it as an example of crude Florentine 'municipal' speech in De vulgari: 'Since we ain't got nuthin' else to do, let's eat' would be a colloquial American equivalent of the example he gives. If writers of the illustrious vernacular are to avoid such expressions, we are perhaps forced to reflect that Dante's Comedy, unlike Virgil's lofty Tragedy, is written in the low style (and has a 'happy ending'). For discussions in this vein see Giorgio Barberi Squarotti (“Inferno, XX,” in L'artificio dell'eternità [Verona: Fiorini, 1972]), p. 281; Hollander (“The Tragedy of Divination in Inferno XX,” in Studies in Dante [Ravenna: Longo, 1980], pp. 214-18; and Claudia Villa (“Tra affetto e pietà: per Inferno V,” Lettere Italiane 51 [1999]), pp. 530-33.