The Divine Comedy by Dante ALIGHIERI · Digital Dante Edition with Commento Baroliniano · MMXV ·   Columbia University

Inferno 20


Astrology and Determinism, Deflected

The Undivine Comedy, Chapter 4, “Narrative and Style in Lower Hell”, pp. 79-80; Dante’s Poets, pp. 215-22;  “True and False See-ers in Inferno 20,” Lectura Dantis: A Forum for Dante Research and Interpretation 4 (1989): 42-54; “‘Why Did Dante Write the Commedia?’ or The Vision Thing,” Dante Studies 111 (1993): 1-8, rpt. Dante and the Origins of Italian Literary Culture; “Contemporaries Who Found Heterodoxy in Dante, Featuring (But Not Exclusively) Cecco d’Ascoli,” Dante and Heterodoxy: The Temptations of 13th Century Radical Thought, ed. Maria Luisa Ardizzone (Newcastle upon Tyne: Cambridge Scholars Publishing, 2014), pp. 259-75. 
  • the bolgia of divination and false prophecy—and yet Dante does not here fully engage the most important medieval form of divination, astrology, one in which he himself (according to the commentator Benvenuto da Imola) took pleasure
  • instead, he litigates the truth value of classical poetry and classical culture
  • the classical seer Tiresias and gender: “Hardly nobody gets to live two genders in their life” (Caitlyn Jenner)
  • the brief mentions of medieval astrologers Michael Scot and Guido Bonatti recall the astrologer who in real life engaged Dante personally, Cecco d’Ascoli (1257-1327)
  • Virgilio is again, and more explicitly than before, assigned the task of debunking the Aeneid
  • tragedìa vs. comedìa
  • unnamed witches → witch trials in the early modern period (e.g. Salem witch trials of 1692-1693)

Inferno 20 deals with what commentators have traditionally referred to as false prophecy or divination: in other words, the gamut of activities with which humans have attempted to foretell the future and to convince fellow humans that they are able to do so. That seems straightforward enough, and yet . . . in Inferno 20 Dante deflects a crucial issue with which he could have engaged.

This issue is astrology, a pursuit in which Dante himself took pleasure, according to the astute fourteenth-century commentator Benvenuto da Imola: “qui aliquantulum delectatus est in astrologia” (who to some degree took pleasure in astrology). Benvenuto goes so far as to connect the weeping of the pilgrim in Inferno 20 to Dante’s compassion for his own “error”: “Ideo bene fingit se nunc ita plorare compatiens aliis et sibi de errore suo” (Therefore he does well to depict himself now weeping, having compassion for others and himself for his error [Benvenuto commentary, cited in full below]).

The most important form of divination in Dante’s time was without a doubt astrology, which in the medieval period still had academic, scientific, and philosophical standing. In our modern age, “astrology” has declined into a pseudoscience, while the scientific study of the stars is now termed “astronomy.” In Dante’s time, astrology was not distinguished from astronomy.

Dante mentions two medieval astrologers in Inferno 20 (three if we include Asdente). A terzina (Inf. 20.115-17) is devoted to the very important figure of Michael Scot, an astrologer and scholar whose work is central in the history of the transmission of Aristotle in the West:

Michael Scot, (born c. 1175—died c. 1235), Scottish scholar and mathematician whose translations of Aristotle from Arabic and Hebrew into Latin are a landmark in the reception of that philosopher in western Europe.

Scot was famous in the European Middle Ages as an astrologer and soon acquired a popular reputation as a wizard. He is first recorded at Toledo in 1217, where he finished translating the treatise of al-Biṭrūjī (Alpetragius) on the sphere. In 1220 he was in Bologna and during the years 1224–27 may have been in papal service, as he is mentioned in several papal letters. A pluralist, he was promoted archbishop of Cashel in Ireland (May 1224) but declined the see a month later. He seems, however, to have held benefices in Italy from time to time. After 1227 he was at the Sicilian court of the Holy Roman emperor Frederick II and was mentioned as recently dead in a poem written early in 1236.

His works are mainly undated, but those on natural philosophy seem to predominate in his earlier, Spanish period, and those on astrology in his later, Sicilian period. At Toledo, in addition to his translation of al-Biṭrūjī, Scot translated Aristotle’s Historia animalium from Hebrew or Arabic. He also translated, perhaps at this time, Aristotle’s De caelo, and he was probably responsible for the translations of the De anima and the commentary by Averroës that is found in the same manuscripts. There is no evidence that Scot translated Aristotle’s Physics, Metaphysics, or Ethics.

He wrote three treatises on astrology, and several alchemical works were ascribed to him. He appears in Dante’s Inferno (xx) among the magicians and soothsayers and has the same role in Boccaccio.

(“Michael Scot,”

Immediately after the sighting of Michael Scot, Virgilio points to the thirteenth-century Italian Guido Bonatti: “Vedi Guido Bonatti” (Inf. 20.118). Bonatti is, according to Cesare Vasoli, “il più autorevole trattatista di astrologia del Medioevo italiano” (the most authoritative author of astrological treatises in the Italian Middle Ages; see “Bonatti, Guido,” in Dizionario Biografico degli Italiani, available online at, accessed 10/27/2015). Vasoli cites Bonatti’s self-description from 1260: “astrologus Communis Florentiae de Forolivio” (astrologer of the Commune of Florence from Forlì).

The intellectual profiles of Michael Scot and Guido Bonatti (who was astrologer to various lords whose careers interested Dante: Ezzelino da Romano, Guido Novello da Polenta, and Guido da Montefeltro) offer many points of interest to the author of the Commedia. Dante himself both concedes the importance of the stars in determining some human traits and dispositions but also vehemently rejects the idea that they determine our choices—because we have free will, as he states categorically in Purgatorio 16 (see especially verses 73-6).

At the same time there is no denying that Dante engages in a kind of generic determinism in the Commedia, a poem that reads the future with respect to every character we meet. It is clear that determinism in this non-technical sense is built into the very enterprise of writing a poem that adjudicates the afterlife.

Moreover, Dante might be seen to flirt with determinism in a more technical sense in his treatment of Boniface VIII in Inferno 19. We recall that Nicholas III claims to have read in the book of the future—the “scritto” of Inferno 19.54—that Boniface will eventually join him in the third bolgia of the eighth circle.

By condemning Boniface to Hell while the Pope was still alive (Dante’s journey through Hell takes place in 1300, and Boniface did not die until 1303), Dante effectively denies Boniface the benefit of his free will. In doctrinal terms, Boniface has the opportunity to repent until the last moment of his life, as Dante knew full well; he dramatizes precisely this doctrine of repentance in extremis in the case of Bonconte da Montefeltro in Purgatorio 5. The case of Boniface therefore seems dangerously deterministic, even discounting the generic determinism that inheres to the genre of afterlife vision.

In Inferno 20, Dante’s substitution of classical diviners for medieval astrologers is a way of distancing what he does in the Commedia from the practice of divination by contemporary medieval astrologers. It is worth considering in this context the links between Dante and the astrologer Cecco d’Ascoli, the author of the philosophical poem Acerba. Cecco, whose real name was Francesco Stabili, is an exact contemporary of Dante’s (Cecco’s dates are 1269-1327).

Cecco d’Ascoli attacks Dante on a number of counts in Acerba, where he makes clear that he views Dante as engaged in an inferior version of his own project. Very interesting in this context is Cecco’s indictment of verse 89 of Inferno 7, which he considers an example of determinism on Dante’s part. In the Appendix to the Introduction to Inferno 7, I discuss the controversy generated by Cecco’s indictment of this verse. It is important to bear in mind not only that Cecco’s attack occurred but also that it was not dismissed as trivial by contemporaries. Rather, both Boccaccio and Benvenuto da Imola took Cecco’s concern about Inferno 7.89 seriously. Benvenuto defends Dante by citing Purgatorio 16 on free will, thus showing both that he understands the critique and knows the passage in the Commedia with which to combat it.

If Dante’s project did not overlap in some way with that of professional astrologers, Cecco would have had no interest in competing with him.

Besides astrology, there is another contemporary direction in which Dante could have taken the bolgia of false prophets: he could have used it as an opportunity to explore the great ferment of religious prophets who dot the spiritual and intellectual landscape in his world. The views of various claimants to inspired truth existed in tension, and many attacks of “false prophet” are launched and rebutted and litigated throughout this period. To give just one example of the historical complexities around the issue of “false prophecy” we can consider the figure of Joachim of Flora, the Cistercian abbot and mystic who died in 1202. Dante places Joachim in the heaven of the sun and describes him as “endowed with prophetic spirit”: “di spirito profetico dotato” (Par. 12.141). And yet, having been supported by the Church while alive, Joachim’s work excited suspicion later on: it was condemned by Alexander IV in 1256, his central doctrine was confuted by St. Thomas in the Summa Theologica (I-II, Q. cvi, a. 4), and its Franciscan exponents were sternly repressed by St. Bonaventure.

In short, in Inferno 20 Dante is dealing with versions of himself, distanced because of their potential proximity. Benvenuto da Imola was right on target when he wrote of Inferno 20 that “the present matter touches the author himself”:

praesens negotium tangebat autorem ipsum, qui aliquantulum delectatus est in astrologia, et voluit praedicere aliqua futura, sicut patet in libro isto. Ideo bene fingit se nunc ita plorare compatiens aliis et sibi de errore suo.

the present matter touches the author himself, who to some degree took pleasure in astrology, and wanted to predict some future things, as appears in this same book. Therefore he does well to depict himself now weeping, having compassion for others and himself for his error. (Benevenuti de Rambaldis de Imola, Comentum super Dantis Aldigherij Comoediam, ed. J. P. Lacaita [Florence: Barbèra, 1887], commentary to Inferno 20.19-24, available through the Dartmouth Dante Project)

Perhaps with the qualification that Dante wanted to predict “some future things”—“aliqua futura”—Benvenuto intends the Commedia’s specific prophecies regarding the future: the prophecy of the coming of the veltro in Inferno 1.101, the prophecy of the DXV in Purgatorio 33.43, and so forth. But, by bringing up the issue of astrology early in his commentary to Inferno 20, long before Dante introduces the contemporary astrologers toward the canto’s end, Benvenuto shows that he understands Dante’s complicity in the huge issue that has been swept under the proverbial rug. The real point is that the entire Commedia is a prophecy, a revelation concerning matters hidden to ordinary mortals, not given to us to see.

* * *

Instead of litigating astral determinism or mystical prophecies about the future of Christendom in Inferno 20, Dante litigates the truth value of classical culture.

As we have seen, Dante chooses to avoid the issue of truth claims and prophecy in contemporary society in Inferno 20. Instead, Dante turns his treatment of false prophecy into an indictment of the limitations and hubris of classical culture. This canto is thus linked to others where there are negative characterizations of figures from classical antiquity, for instance Inferno 9 (featuring Erichtho, Medusa, etc.) and Inferno 14 (Capaneo).

In Inferno 20 Dante focuses on the soothsayers and diviners of antiquity. He features four classical figures, each one taken from one of the great epic poems of classical antiquity.

Inferno 20 falls into four narrative segments. Lines 1-30 present the sin of divination in general terms. Lines 31-57 introduce famous diviners of antiquity, each of whom figures in and represents a major classical text:

  1. Amphiaraus from Statius’ Thebaid
  2. Tiresias from Ovid’s Metamorphoses
  3. Arruns from Lucan’s Pharsalia
  4. Manto from Vergil’s Aeneid

Lines 58-99 encompass the digression on the founding of the city of Mantova. Lines 100-130 contain Dante’s query regarding further diviners, and Virgilio’s response, in which he names Eurypylus from the Aeneid and the contemporary practitioners discussed above.

Inferno 20 is also an important installment in the ongoing Vergilian narrative: Virgilio does most of the speaking in Inferno 20 and he speaks with unusual passion. Perhaps because of the severe condemnation of classical culture in this canto, Virgilio feels the need to distance himself from the sinners here with greater than usual vigor. Virgilio speaks with the same kind of harshness to Capaneo in Inferno 14, and there are interesting points of contact, centered on the city of Thebes and its dark history, between Capaneo and three of the diviners of Inferno 20.

When Dante weeps at the sight of the deformed bodies of the diviners, whose heads are twisted around so that their tears run down their buttocks, Virgilio rebukes him in no uncertain terms: “Qui vive la pietà quand’ è ben morta” (Here pity only lives when it is dead [Inf. 20.28]).

Virgilio’s strong condemnation of the diviners requires him, moreover, to inveigh against the prophetess Manto, featured in his own poem, the Aeneid, where she is the founder of the city Mantova. We recall that Mantova is the city where the Latin poet was born, as we remember from Inferno 1.58-9: “e li parenti miei furon lombardi, / mantoani per patria ambedui” (Both of my parents came from Lombardy, / and both claimed Mantua as native city).

Virgilio now retells the story of Manto, altering the earlier account found in the tenth book of the Aeneid. The Latin poem relates that the prophetess bears a child, Ocnus, who founds the city and gives it his mother’s name: “qui muros matinsque dedit tibi, Mantua, nomen” (who gave you walls and the name of his mother, O Mantua [Aen. 10.200]). The Commedia, on the other hand, relates that Manto, childless and indeed a “savage vergin” (“la vergine cruda” [Inf. 20.82]), settled and died in a spot later chosen by men from the surrounding regions as suitable for a city: “Fer la città sovra quell’ossa morte” (They built a city over her dead bones [Inf. 20.91]). Virgilio’s correction of the text of the Aeneid with respect to Manto constitutes another authorial self-correction of the sort that Dante-poet fabricated previously at the end of Inferno 14, where Virgilio explains that the river Lethe is not in Hell but in Purgatory, a contradiction of the description of the underworld in Aeneid 6.

Most interesting about Virgilio’s speech detailing the founding of Mantova is his closing injunction to the pilgrim to disregard all other accounts of his birthplace (“la mia terra” in Inferno 20.98). The only true version of the founding of Mantova is the one he has just heard, says Virgilio. In fact, the pilgrim must “let no lie defraud the truth”, in other words he must reject all other accounts as false:

Però t’assenno che, se tu mai odi
originar la mia terra altrimenti,
la verità nulla menzogna frodi.  (Inf. 20.97-9)

Therefore, I charge you, if you ever hear
a different tale of my town’s origin,
do not let any falsehood gull the truth.   

This passage’s programmatic undermining of the Aeneid is discussed in Dante’s Poets: “But in what source could Dante find the story of ‘mia terra’ told ‘altrimenti, if not in the Aeneid? According to Vergil’s own statement then, the Aeneid is a text that—like the false prophets of this bolgia—is capable of defrauding the truth” (Dante’s Poets, p. 217).

Echoing Inferno 13, where Virgilio positions his own account of a man changed into a tree in the Aeneid as a “cosa incredibile” and the Commedia’s account of the metamorphosis of Pier della Vigna as true, in Inferno 20 Virgilio dismisses as false the account of the founding of Mantova told in Aeneid 10 and replaces it with the true version of the Commedia.

All of this feeds into the important information about genre that Virgilio offers toward the end of Inferno 20, where he calls his Aeneid “l’alta mia tragedìa” (my high tragedy [Inf. 20.113]). At the beginning of canto 21 Dante reconfirms that his poem is, instead, a “comedìa”:

  Così di ponte in ponte, altro parlando
che la mia comedìa cantar non cura,
venimmo... (Inf. 21.1-3)
  We came along from one bridge to another,
talking of things my Comedy is not
concerned to sing.

The three occasions on which Dante uses the genre terminology comedìa vs. tragedìa are all in Inferno:

  1. Inferno 16.128: the reference to comedìa embedded within the arrival of Geryon
  2. Inferno 20.113: the reference by Virgilio to his own “alta tragedìa”
  3. Inferno 21.2: Dante refers to “la mia comedìa” as though in reply to Virgilio’s “alta mia tragedìa” from the end of the previous canto

Dante uses this constellation of moments to define his poem in juxtaposition to Vergil’s Aeneid, the greatest poem of antiquity that he had read, through a system of associations analyzed in Dante’s Poets:

The language of line 99, with its harsh juxtaposition of verità and menzogna, as well as the appearance in line 113 of tragedia, the Comedy’s second genre term, indicate the close ties which bind this episode to that of canto XVI: Vergil’s poem, defined as a tragedia, is, at least at times, a lie that defrauds the truth, while Dante’s poem is a truth that sometimes bears the face of a lie. Such a poetic truth is, as we already know, a comedìa, a term Dante will now use for the last time in the opening verses of canto XXI. We note the progressive unfolding of information: first the implicit association of the Aeneid with menzogna in XX, 99; then Vergil’s reference to his poem as “l’alta mia tragedia” in XX, 113, which results in the alignment of menzogna and tragedia; and finally, safely distanced from the tragedies of the ancients by the boundary between cantos XX and XXI, the reference to Dante’s poem as “la mia comedìa” in XXI, 2, which confirms that his poem is the opposite of the Aeneid and therefore also of menzogna. (Dante’s Poets, pp. 217-18)

There is a second diviner from the Aeneid in Inferno 20: the minor character Eurypylus is revised by Dante from a common foot-soldier in the Aeneid to an augur in Inferno 20.106-17. Given the massive revisions of the Aeneid that we find in this canto, it is surprising that Virgilio should use the opportunity of pointing to Eurypylus to commend Dante for knowing the Aeneid, his “alta tragedìa” in verse 113, in its entirety:

Euripilo ebbe nome, e così ’l canta
l’alta mia tragedìa in alcun loco:
ben lo sai tu che la sai tutta quanta.  (Inf. 20.112-14)

His name’s Eurypylus; a certain passage 
of my high tragedy has sung it so
you know that well enough, who know the whole of it. 

While in Dante’s Poets I stress the negative implications of the terzina devoted to the revision of Eurypylus, I note now that—despite the ambiguities of the moment in which this tribute to Dante’s knowledge of the Aeneid occurs—there is still genuine satisfaction in witnessing Dante’s claim to know Vergil’s tragedìa from stem to stern: “tutta quanta”. There is, moreover, something quite remarkable about the simplicity and directness of verse 114: the spoken cadence of “ben lo sai tu che la sai tutta quanta” carries the conviction of lived experience.

* * *

The treatment of Tiresias and Manto reverts to the gendered and sexualized language that is featured in Inferno 18 and that needs to be systematically explored in the treatment of lower Hell. Here the emphasis is very much on the body, apparent from the frequent use of words referring to body parts: 26 in the course of 126 verses. (For charts and further discussion of the most “body-saturated” canti in Inferno, see the Introduction to Inferno 25.) The bodies of the diviners are twisted and distorted. Their punishment for trying to see too far “ahead” is to have their heads now literally face backwards: “perché volle veder troppo davante, / di retro guarda e fa retroso calle” (and since he wanted so to see ahead, / he looks behind and walks a backward path [Inf. 20.38-9]).

Dante takes this opportunity to refer to Tiresias as the ancient prophet who essentially had a transgender experience, having experienced life as both male and female: “quando di maschio femmina divenne” (when he from male became female [Inf. 20.41]). And the description of Manto, the “vergine cruda” of Inferno 20.82, dwells on her sexuality in crude and degrading fashion that is highly gendered. There are references to her “breasts” (“mammelle” [Inf. 20.52]), her “hairy parts” (“ogne pilosa pelle” [Inf. 20.54]) and to her “loosened braids”: “le trecce sciolte” (Inf. 20.53). The sexualization of hair, present also in the treatment of Thaïs in Inferno 18 and notably absent from the circle of lust in Inferno 5, is a typical misogynist trope employed to attack female transgression and sexuality.

This gendered treatment of false prophecy, emphasized in the figure of Manto, is reprised at canto’s end with the fascinating and depressing reference to anonymous contemporary female diviners:

  Vedi le triste che lasciaron l’ago,
la spuola e ’l fuso, e fecersi ’ndivine;
fecer malie con erbe e con imago. (Inf. 20.121-23)
  See those sad women who had left their needle,
shuttle, and spindle to become diviners;
they cast their spells with herbs and effigies.

There is no language that more confines females to their gendered niche than the words “ago”, “spuola,” and “fuso”: “needle,” “shuttle,” and “spindle” (Inf. 20.121-122). The point here is that these “triste”—sad and miserable females—should have stayed faithful to their needles and spindles, rather than branching out to “make themselves diviners” (“fecersi ’ndivine” [122]).

We note the contrast between the treatment of these unnamed contemporary witches to that of the male astrologers whom Dante mentions by name. Michael Scot was popularly considered a wizard (see the Encyclopedia Britannica entry cited above), a view that Dante clearly endorses: he uses the word “magic” in relation to Michael Scot, writing that “veramente / de le magiche frode seppe ’l gioco” (he certainly / knew how the game of magic fraud was played [Inf. 20.116-17]). This characterization is the more noteworthy in that the adjective “magiche” in “magiche frode” is the only form of the term “magic” to appear in the Commedia. It is a hapax and as such it draws extraordinary attention to the magical component of astrology and to Michael Scot’s status as a wizard.

But Michael Scot was a mathematician and a scholar, a translator of Aristotle from Arabic, and he maintains some of the dignity accorded to his (male) professional attainments in Dante’s Hell. So too for Guido Bonatti, despite the “fama di empietà e di oscura stregoneria” (fame of impiety and witchcraft) attributed to him by Vasoli in the biography cited above.

Even the lowly cobbler of Parma is referred to by his nickname, Asdente, in verse 118. However, Asdente is in one way connected to the unnamed women who follow him in Virgilio’s presentation. He is castigated for not having stuck to the tools of his trade, “his cord and leather”: “ch’avere inteso al cuoio e a lo spago / ora vorrebbe” (who now would wish he had attended to / his cord and leather [Inf. 20.119-20]). Asdente’s cuoio and spago introduce the list of  tools that the women foolishly left behind to become diviners: “l’ago, / la spuola e ’l fuso” [Inf. 20.121-2]). From cord and leather to needles, shuttles, and spindles—Asdente’s lower class status seems to position him as the pivot to the anonymous witches who “cast their spells with herbs and effigies”: “fecer malie con erbe e con imago” (Inf. 20.123).

Manto, a pagan female sorceress who has none of those offsetting male professional attainments to her credit, is treated in a harsh and degradingly sexualized manner in this canto, but at least she has a name, and a city named after her, however the story of its founding is negatively revised. The lowly status of the unnamed female witches in Inferno 20 compels us to think of the many women who would be condemned to cruel and gendered and even anonymous fates, as witches, in the centuries to come.

“Hardly nobody gets to live two genders in their life” (Caitlyn Jenner)

The figure of Tiresias is described in a way that explicitly recalls the Ovidian tale told in Metamorphoses Bk 3:316–36, conjuring the prophet as one who experienced life both as male and as female:

Vedi Tiresia, che mutò sembiante
quando di maschio femmina divenne 
cangiandosi le membra tutte quante; 
e prima, poi, ribatter li convenne
li duo serpenti avvolti, con la verga,
che riavesse le maschili penne. (Inf. 20.40-45)

And see Tiresias, who changed his mien 
when from a man he turned into a woman,  
so totally transforming all his limbs  
that then he had to strike once more upon  
the two entwining serpents with his wand  
before he had his manly plumes again. 

The story told by Ovid of Tiresias witnessing and striking two copulating snakes—and as a result being transformed into a woman until he sees them again seven years later, strikes them again, and is transformed back into a man—is here evoked by Dante in language that is highly gendered: “maschio”, “femmina”, “maschili” all occur in a five-verse span.

This story is further evoked in Inferno 25, where men and snakes copulate and where Cadmus is named in verse 97. Cadmus and his wife Harmonia are transformed in Metamorphoses 4:563-603 into two loving snakes, reminiscent of the copulating snakes struck by Tiresias.

The description of Tiresias in Inferno 20.40-45 is part of a discourse on gender that runs through the Commedia. Moreover, the copulating snakes of the Tiresias episode in Metamorphoses 3:316-36 (the passage evoked in this canto) is undoubtedly a key intertext that resonates in Dante’s extraordinary inventions in Inferno 25.

Recommended Citation

Barolini, Teodolinda. "Inferno 20 : Astrology and Determinism, Deflected." Commento Baroliniano, Digital Dante. Center for Digital Research and Scholarship. New York, NY: Columbia University Libraries, 2015.

Coordinated Reading