Plato, Mathematician and Myth-Maker

Pisano, Giovanni, 1240?-1320?. c.1284. Siena Duomo: det.: Plato. Place: Museo dell’Opera del Duomo (Siena, Italy).

The Republic, The Symposium, The Phaedrus, The Apology, and The Phaedo––these are just a few of the works of Plato that were not widely available throughout most of the Middle Ages. No extended depiction of the most just city in the Republic. No discussion of love in The Symposium and The Phaedrus. No self-defense for Socrates at his trial as found in The Apology, and no final dialogue before his suicide as found in The Phaedo. For lovers of great texts, especially Plato, such news can be shocking. What kind of Plato does a person know if they don’t have these key works? How much of Socrates’ life and Plato’s philosophy could even be known? These are the questions that many medieval scholars of the Latin Platonist tradition have dedicated their lives and careers to answering, and the answers can be quite surprising.

One aspect of this research that ought to be appreciated by the wider reading public (outside of the narrow confines of medievalists) is that Plato’s Timaeus wasthe most widely available Platonic work throughout most of the Middle Ages. In fact, examining the text of the Timaeus and why itwas such one of the few Platonic texts preserved reveals how peculiarly modern our current canon of Platonic literature is.

What we value in Plato was not necessarily what late antique or medieval readers valued, and yet, their ability to read well meant that they understood a lot more than might be supposed. An attention to the reception history of Plato’s Timaeus can give modern readers of Plato a better appreciation for the importance of both mathematics and poetry in Platonic philosophy.

The Timaeus is Plato’s work on the origins of the universe. It begins with a dialogue between Timaeus, Socrates, Hermocrates, and Critias, in which Socrates expresses a desire for a “moving image” of the city they had been talking about the day before. The summary of the previous day’s discussion appears to bear some resemblance to the conversation found in the Republic although scholars are divided over whether this summary perfectly matches the Republic that we now possess. Regardless of its accuracy, this summary would have been the closest a medieval reader would have had to a taste of the Republic. The opening dialogue covers all sorts of fascinating topics from Solon’s visit to Egypt, oral culture, the mythic origins of writing, and the myth of Atlantis, but the bulk of the work features a narration about the origins of the universe recounted by the Pythagorean, Timaeus.

The Timaeus was received in the Middle Ages through three main channels of Latin translations: the translation of Calcidius (which ends at 53b), the translation of Cicero (available but not widely used or even known, which ends at 42b), and the excerpts from the Ciceronian translation of the Timaeus that can be found in Augustine’s City of God. Although it does not contain the whole text of the Timaeus, Calcidius’ translation is much more complete than Cicero’s: rather than giving merely the speech of Timaeus like Cicero’s translation does, it includes the opening dialogue (even though the commentary itself ignores it).

Most modern Plato scholars would probably not choose The Timaeus as theone and only work they could save from destruction for all time. But, a better understanding of who Calcidius was and why he wrote the commentary on the Timaeus suggests that the preservation of the Timaeus in the Latin West was not an accident of fate. Rather, the results of Gretchen Reydams-Schills’ lifelong study of Calcidius give a plausible reason for why Calcidius’ commentary may have been the Platonic work of choice for many late antique philosophers.

Reydams-Schils argues that Calcidius wrote his commentary as an introduction to the Platonic corpus, essentially reversing the Middle Platonic curriculum, which traditionally ended with the Timaeus. One major piece of evidence for this theory is that Calcidius’ commentary often reserves discussion of harder philosophical concepts for the end of the commentary.Furthermore, unlike the Neoplatonists, Calcidius did not read the Timaeus synoptically and believed strongly in the importance of sequential reading of the Platonic corpus. In Calcidus’ Platonic curriculum, the Timaeus came first with its teachings on natural justice, then the Republic with its teaching of positive justice, and finally, the Parmenides came with its teaching of the forms and intelligible realities. Calcidius believed that a thorough understanding of mathematics was necessary for understanding of almost all of the Platonic works, which is why his commentary on the Timaeus turns out to be something like a crash course in Pythagorean mathematics.

Thus, although the Timaeus was one of the only Platonic works available throughout the early Middle Ages, Calcidius’ commentary gave readers some introduction to the entire Platonic corpus as well as a great deal of Pythagorean mathematics. Perhaps there might be good reason for a philosopher to save The Timaeus (especially a copy with Calcidius’ commentary)from a burning building!

Plato; Chalcidius (translation). Timaeus. Manuscript. Place: Bodleian Library, University of Oxford, <a href=’’></a>.

Medievalists who study the textual reception of the various translations of The Timaeus have been able to identify a shift in kinds of interest in Plato over time. The primary Latin translation of the Timaeus used until the eleventh century was Cicero’s. Medieval scholars used to assume that the revival of Calcidius began with the twelfth century Platonists, but Anna Somfai has demonstrated that the proliferation of copies of Calcidius’ text and commentary began in the eleventh century when championed by Lanfranc of Bec (c.1050). The late twelfth-century actually experienced a decline of copying the Timaeus as interests shifted towards other texts.

What motivated the eleventh-century interest in Calcidius appears to have been the mathematical content of the Calcidian commentary because, by the Carolingian period, much of the actual content of the quadrivial arts had been lost, and scholars in the Middle Ages attempted to piece together what scraps of it remained from a variety of sources. Calcidius’ commentary on the Timaeus appears to have been particularly valued as a source text for the quadrivial (or mathematical) arts. As my two previous MI blogs have explored here and here, medieval thinkers in the traditional liberal arts tradition recognized that the quadrivial arts were the foundation for philosophical thought, even if they had few textual sources for actually studying them.

And although some of the interest in the kinds of mathematics found in the Timaeus and Calcidius’ commentary may have declined after the twelfth century, it was by no means lost completely. As David Albertson has demonstrated, the mathematical interest in Plato found in the work of the twelfth-century scholar, Thierry of Chartres, would eventually be picked up by the fifteenth-century scholar, Nicholas of Cusa, and many scholars have noted resonances of Cusa’s quadrivial agenda in the thinking of Leibniz, the founder of calculus:

It seems that God, when he bestowed these two sciences [arithmetic and algebra] on humankind, wanted to warn us that a much greater secret lay hidden in our intellect, of which these were but shadows. (Leibniz as quoted by Albertson, p.2)

Bernardus Silvester. Liber fortunae, also known as Experimentarius.. Manuscript. Place: Bodleian Library, University of Oxford, <a href=’’></a>.

Even though the interest in scribal copying of the Timaeus seems to have declined somewhat by the twelfth-century, another kind of imitatio or translatio studii was being enacted by a different kind of scholar, Bernard Silvestris. He wrote a prosi-metric telling of the creation of the world that emulates Plato’s Timaeus. The title of his work, Cosmographia, roughly translates as “universe writing,” and Bernard delivered an oral performance of itbefore Pope Eugenius III in 1147. Bernard’s creative retelling of the Timaeus poetically depicts the role of imitation in the divine creation of the world in the form of “divine writing.” Performatively, the Cosmographia demonstrates that this divine writing is then imitated by poets in the form of human writing. In other words, Bernard values Plato’s Timaeus here not merely for its insights into mathematics or even the structure of the universe, but also what this mathematics in the universe implies about the mimetic nature of poetry itself.

As many literary scholars have demonstrated, much of the European literary tradition follows suit in seeing the value of Timaean Platonism for the production of literature. This interest can be seen in such diverse authors as Alan of Lille, Chrétien de Troyes, and Dante.

While I would personally be loath to give up the access to the Platonic corpus that I possess, the medieval reception of the Timaeus constantly pushes me to reconsider how I am reading that corpus. Having a large corpus of texts actually places an onus on the modern reader to ask the question of where to place the textual emphasis: Which texts of Plato should be considered central (and which ones periphery) and why? For example, should Plato’s Republic be considered his last word on poets and poetry? What would happen if Plato’s Timaeus were given more weight?

C.S. Lewis once wrote in his introduction to On the Incarnation by Athanasius:

Every age has its own outlook. It is specially good at seeing certain truths and specially liable to make certain mistakes. We all, therefore, need the books that will correct the characteristic mistakes of our own period. And that means the old books.

These words about reading the great books can also apply to reading the old books as they were read by past readers. Understanding medieval readings of Plato might very well be a good counterweight to modern presuppositions about who Plato was and what he was about. How might the idea of Plato as both a mathematician and myth-maker transform our modern understanding of Platonism and its history?

Lesley-Anne Dyer Williams is a Professor for Memoria College’s Masters of Arts in Great Books program and graduated with her doctorate from the University of Notre Dame’s Medieval Institute in 2012. She was also the founding director Liberal Arts Guild at LeTourneau University. Her research focuses upon twelfth-century Platonism and poetry, especially Thierry of Chartres and Bernard Silvestris.

Lesley-Anne Dyer Williams
Public Humanities Postdoctoral Fellow
Medieval Institute
University of Notre Dame

For Further Reading:

Albertson, David. Mathematical Theologies: Nicholas of Cusa and the Legacy of Thierry of Chartres. Oxford University Press, 2014.

Baxter, Jason M. The Infinite Beauty of the World: Dante’s Encyclopedia and the Names of God. Peter Lang, 2020.

Bernardus Silvestris. Poetic Works. Edited by Winthrop Wetherbee, vol. 38, Harvard University Press, 2015.

Caiazzo, Irene. “Teaching the Quadrivium in the Twelfth-Century Schools.” A Companion to Twelfth-Century Schools, edited by Cédric Giraud, translated by Ignacio Duran, vol. 88, Brill, 2019, pp. 180–202.

Calcidius. On Plato’s Timaeus. Edited by John Magee, vol. 41, Harvard University Press, 2016.

Chenu, M. D. “The Platonisms of the Twelfth Century.” Nature, Man and Society in the Twelfth Century: Essays on New Theological Perspectives in the Latin West, translated by Jerome Taylor and Lester K. Little, vol. 37, University of Toronto Press, 1997.

Dronke, Peter. The Spell of Calcidius: Platonic Concepts and Images in the Medieval West. SISMEL edizioni del Galluzzo, 2008.

Gersh, Stephen. Middle Platonism and Neoplatonism: The Latin Tradition. Vol 1 and Vol 2. University of Notre Dame Press, 1986.

Hoenig, Christina. Plato’s Timaeus and the Latin Tradition. Cambridge University Press, 2018.

Murray, K. Sarah-Jane. From Plato to Lancelot. Syracuse University Press, 2008.

Plato. Plato’s Cosmology: The Timaeus of Plato Translated with Running Commentary. Edited by F. M Cornford, Routledge, 1937.

Reydam-Schils, Gretchen. “Myth and Poetry in the Timaeus.” Plato and the Poets, edited by Pierre Destrée and Fritz-Gregor Herrmann, Brill, 2011.

Reydams-Schils, Gretchen J. Calcidius on Plato’s Timaeus: Greek Philosophy, Latin Reception, and Christian Contexts. Cambridge University Press, 2020.

Somfai, Anna. “The Eleventh-Century Shift in the Reception of Plato’s Timaeus and Calcidius’ Commentary.” Journal of the Warburg and Courtauld Institutes, vol. 65, 2002, pp. 1–21.

Stock, Brian. Myth and Science in the Twelfth Century. Princeton University Press, 1972.

Wetherbee, Winthrop. Platonism and Poetry in the Twelfth Century. Princeton University Press, 1972.

Ambrosiana MS B44 Inferiore and an Easter Homily of Maximus of Turin

MS B44 Inferiore of Milan’s Ambrosiana Library is an unstudied aestivial (summer season) homiliary from the thirteenth century. It is an exceptionally large manuscript, measuring approximately 40cm by 30cm. An eighteenth-century librarian of the Ambrosiana marked it as a homiliary of the “Ambrosian rite,” which is not a description meaningful for ascertaining the paradigms on which the homiliary’s structure is based. The invocation of the “Ambrosian rite” does, however, point to peculiarities in the Lombard region’s liturgical calendar which B44 might reflect. The homiliary’s reflection of local liturgical traditions could best be judged through a study of its “sanctorum” portion; this, however, was not the focus of my time with the manuscript. Despite its large size and length, the homiliary only spans the summer part of the liturgical year. Its de tempore section begins with the Easter Vigil and ends with the Feast of the Nativity of the Virgin. The Feast of Mary’s Nativity was locally important since the Milanese Duomo was dedicated, from at least the eleventh century, to the Blessed Virgin’s birth.

            To familiarize myself with the manuscript’s structure and homiletic content, I surveyed the sermons it included for the Easter season (1v-52r), noting sermon incipits from Easter until Pentecost. Though for the sanctorale section, there are a wide variety of authors, the Easter de tempore section largely consists of homilies from Sts. Ambrose, Bede, Gregory, and Augustine. The sermon choices are, however, eclectic, and do not match the arrangement of the paradigmatic homiliaries summarized by Réginald Grégoire in his still-unsurpassed Homéliaires Liturgiques Médiévaux. In short, MS Inf. B44’s Easter sermons do not match those included in the Roman and Toledan homiliaries, nor those in the collections of Pseudo-Fulgencius, Paul the Deacon, or Romain d’Agimond. As far as contemporary homiletic developments go, Inf. B44 also is far removed from the pocket-manuscript homiliaries popular among the mobile mendicants; more generally, the patristic collection of Easter homilies here does not reflect high medieval developments in preaching. No “scholastic” sermons based around themae are included, nor is there any trace of the politically and socially-charged “activist” preaching of mendicants like Giordano da Pisa (1255-1311) or Remigio de Girolami (d. 1319). In short, though Inf. B44 compiles an eclectic set of sermons, it is a conservative exemplar of the homiliary genre.

            The description of the eighteenth-century Ambrosiana librarian on the manuscript’s first folio also notes that B44 Inf. was acquired for the Ambrosiana in the seventeenth century, when it was removed from Milan’s cathedral. It is unknown if the homiliary had been a possession of the cathedral from the outset, and, if not, why or when it was moved to the cathedral. Judging by the highly moralizing and interior-focused content of the Easter sermons, it is possible that the homiliary had been used by the cathedral canons or a northern Italian monastic community. From its large size, it seems the homiliary likely would have stayed in one place, for use in private mediation or as an aid for the composition of monastic sermons. If we seek a more specific paradigm, it should be noted that B44 Inf. shares basic similarities with high-medieval Cistercian homiliaries copied in northern Italian and Burgundian monasteries, such as the house of Morimondo near Milan. These Cistercian homiliaries were usually fairly large, written in twelfth-century miniscule, and included sermons of Augustine, Bede, Ambrose, and Gregory—all characteristics that B44 Inf. shares.[1] However, further study of the Cistercian homiliaries of northern Italy is necessary to ascertain whether these and our manuscript conform to a common paradigm.

This image has an empty alt attribute; its file name is Maximus-of-Turin-Miniature-from-Medieval-Manuscript.jpg
Saint Maximus of Turin, Anonymous (Italian, Piedmontese), Carte Sciolte, n. 390, Archivio Storico della Città, Turin, from Codice degli Statuti di Torino o Codice della Catena,” 1360.

            Particularly interesting among Inf. B44’s Easter sermons is the second entry for the fifth day after Easter, located between ff. 16v and 17v. This homily, misattributed in the manuscript to St. Ambrose (probably as a result of local enthusiasm for that venerable bishop), is actually a probable composition of St. Maximus of Turin, and its main theme—defending oneself from lustful temptations—coheres well with the manuscript’s probable monastic origin. However, how the sermon conveys this theme is in no way typical, as it does so by extended engagement with the story of Ulysses and the Sirens. Though in Late Antiquity, scientific exegesis of Greek mythology was very common in neo-Platonic circles, Christocentric engagement with a mythological text is a rare phenomenon, even within Maximus’ own homiletic corpus.

            To provide a brief analysis of the sermon: Maximus begins by recalling the passage of Ulysses’ ship past the isle of the Sirens, whose lusty song is irresistible to the sailors. Because Ulysses knows that the ship will be lost if it is captured by the siren song, he ties himself to the mast. For Maximus, the mast and the ship to which the sailors cling are figures of the cross of Christ, on which all sin is expiated. Maximus soon moves from the example of Ulysses—whose story he calls “fictive and not factual”—to Moses’ healing of his people by means of a snake affixed to a staff. Unlike the Ulysses example, the history of the Jewish people is factual, and so truly prefigures Christ’s sacrifice. It can be argued that Maximus’ Christocentric interpretation of Ulysses’ binding to the mast is inspired by Christian exegesis of the Hebrew Scriptures, the methods of which Maximus then applies to Greek myth. There is, after all, a strong exegetical tradition, beginning already with the second century Christian apologist Justin Martyr, which sees ships—specifically Noah’s ark—as a figure of the cross. From there, the paradigm might be easily transferred even to the ships of Greek myth. But transference is not all that Maximus is doing, notwithstanding his curt dismissal of Ulysses’ story. For later in the sermon Maximus encapsulates salvation-history thus: “Fittingly is he crucified on wood so that, since man was deceived in paradise by the tree of desire, he might now be saved by the same tree of wood; and the matter which was the cause of death might be the remedy of health.” In Maximus’ thought, nature itself—here instantiated in wood—constitutes the means of salvation, providing remedies for the bodily weakness of humankind. Since Ulysses’ salvation came directly through divinely-created nature, his tale is not just some forgettable fable. In this conception, however subtly stated, pagans and non-Christians are not outside the economy of salvation, for they, too, exist within a grace-filled nature which can proffer the remedies for their ailments.

For my transcription, translation and recitations (in Modern English and Latin), see my multimedia edition of Maximus of Turin’s homily for the fifth day after Easter in Ambrosiana MS B44 Inferiore.

Mihow McKenny
PhD Candidate in History
University of Notre Dame

[1] Mirella Ferrari, “Dopo Bernardo: biblioteche e ‘scriptoria’ cisterciensi dell’Italia settentrionale nel XII secolo,” in Pietro Zerbi, ed., San Bernardo e l’Italia. Milan, 1993, pp. 253-306.


D’Avray, D. L. The Preaching of the Friars: Sermons Diffused from Paris before 1300. Oxford: Clarendon, 1985.

De Lubac, Henri. Medieval Exegesis: The Four Senses of Scripture. 3 volumes. Translated by Mark Sebanc and E. M. Macierowski. Eerdmans, 1998-2009.

Ferrari, Mirella. “Dopo Bernardo: biblioteche e ‘scriptoria’ cisterciensi dell’Italia settentrionale nel XII secolo.” In Pietro Zerbi, ed., San Bernardo e l’Italia. Milan, 1993, pp. 253-306.

Grégoire, Réginald. Homéliaires liturgiques médiévaux : analyse de manuscrits. Spoleto: Centro italiano di studi sull’Alto Medioevo, 1980.

Longère, Jean. La Prédication Médiévale. Paris: Études Augustiniennes, 1983.

Maximus of Turin. Maximi episcopi taurinensis sermones.Edited by A. Mutzenbecher. Corpus Christianorum Series Latina, vol. 23. Turnhout: Brepols, 1962.

Rahner, Hugo, S.J. Greek Myths and Christian Mystery. Translated by Brian Battershaw. New York: Harper and Row, 1963.

Gawain’s Lying Laughter

The plot of Gawain and the Green Knight centers around agreements. Gawain’s search for the green chapel begins in an attempt to fulfil his vow to exchange blows with the Green Knight.

The Green Knight leaves, holding his decapitated head; Sir Gawain and the Green Knight, England, c. 1400; British Library, Cotton MS Nero A.x, f. 90v.

The journey leads into a second set of agreements—in the three days that he stays with Bertilak (the green knight in disguise), he and Bertilak agree to exchange whatever winnings they gain by day when they meet again at night. Although Gawain successfully exchanges winnings two out of the three nights, kissing Bertilak for each kiss Bertilak’s wife gave him, he keeps a girdle that Lady Bertilak claims protects the wearer from blows: Þer is no haþel vnder heuen tohewe hym þat myȝt (1853).

Gawain’s girdle isn’t the only powerful girdle in medieval literature. Here St. Cuthbert’s girdle cures Aelfflaed. Bede, Prose Life of Cuthbert, Durham, last quarter of the 12th century; British Library, Yates Thompson MS 26, f. 48v.

Thomas D. Hill argues that Gawain’s failure to exchange the girdle is only a venial sin. He bases this argument on Augustine and Aquinas. St. Augustine says that jokes are not lies because the speaker’s disposition and tone are joking. Hill then proposes that tone and disposition must also apply to Thomas Aquinas’s much later concept of jocose lies, or lies that are told for pleasure, which Aquinas categorizes as venial sins.

Hill’s article points out that each exchange of gifts and vow to exchange them on the next day drips with the language of games, joking and laughter (283). Since the agreement to exchange winnings was made for entertainment under mirthful conditions, he suggests that Gawain’s decision to keep the girdle is a venial sin—St. Augustine argues that jokes are not lies. However, Augustine’s jokes use extralinguistic cues like tone of voice and demeanour to communicate the truth non-verbally.

Bertilak preparing to return Gawain’s blow; Sir Gawain and the Green Knight, England, c. 1400; British Library, Cotton MS Nero A.x f. 125v.

This doesn’t happen with Gawain and the girdle. At the exchange where he keeps the girdle, he is mirthful. The text calls him “Sir Gawayn þe gode, þat glad watz with alle” (1925), speaks of his joye, ‘joy’, and emphasizes that he and Bertilak “maden as mery as any men moȝten” (1953). Despite this display of gladness, joy and mirth, Gawain’s disposition does nothing to communicate that he has the girdle. In fact, it conceals his oath-breaking—Gawain blends into the mirthful atmosphere that Bertilak has established at each of the previous exchanges of winnings.

Lines 1935-1971 of Gawain, in which Gawain and Bertilak exchange winnings for the last time; Sir Gawain and the Green Knight, England, c. 1400; British Library, Cotton MS Nero Axx f. 117r.

This is the opposite of St. Augustine’s jokes—Gawain’s non-verbal communication assists his deception of Bertilak.

Bertilak’s laughter, mirth, and games also conceal lies of omission. He withholds information that he can survive a beheading, that he is also the Green Knight, and that he’s asked his wife to tempt Gawain. Yet, he controls the atmosphere of each exchange. He challenges Gawain to a Crystmas gomen, a Christmas game, and appears in the midst of a feast (283). This decision also places the exchange of winnings in the Christmas season—he tells Gawain to come a year afterwards. While Bertilak portrays both oaths as entertainment, their apparent levity both masks and contrasts Bertilak’s darker intentions. Unlike Augustine’s jokes, the non-verbal communication and mirth of Gawain aids in deception rather than revealing the truth.

Rachel Hanks
PhD Candidate
Department of English
University of Notre Dame

Works Cited

Andrew, Malcolm, and Ronald Waldron. The Poems of the Pearl Manuscript: Pearl, Cleanness, Patience, Sir Gawain and the Green Knight. Univ of California Press, 1982.

Hill, Thomas D. “Gawain’s Jesting Lie: Towards an Interpretation of the Confessional Scene in Gawain and the Green Knight.” Studia Neophilologica 52, no. 2 (January 1, 1980): 279–86. doi:10.1080/00393278008587778.

A medieval depiction of a feast; Speculum humanae salvationis, London, 1485-1509; British Library, Harley MS 2838, f.45r.