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Medieval Platonism

Plato, Mathematician and Myth-Maker

Pisano, Giovanni, 1240?-1320?. c.1284. Siena Duomo: det.: Plato. Place: Museo dell’Opera del Duomo (Siena, Italy). https://library-artstor-org.proxy.library.nd.edu/asset/ARTSTOR_103_41822000532257.

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=’http://www.bodley.ox.ac.uk/’>http://www.bodley.ox.ac.uk/</a>. https://library-artstor-org.proxy.library.nd.edu/asset/BODLEIAN_10310768399.

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=’http://www.bodley.ox.ac.uk/’>http://www.bodley.ox.ac.uk/</a>. https://library-artstor-org.proxy.library.nd.edu/asset/BODLEIAN_10310765350.

This blog post is excerpted from the University of Notre Dame’s Medieval Institute Research Blog.

Categories
Medieval Platonism Quadrivium

The Quadrivium and the Stakes for Ordering the Mathematical Arts

 Fyodor Bronnikov, Pythagoreans’ Hymn to the Rising Sun, 1869. Oil on canvas.

Legend has it that Pythagoras sentenced the first person to discover irrational numbers, Hippasus of Metapontum (c.530-450 BC), to death. He was tossed overboard a ship to drown. Why? Pythagoras taught that number was the essence and cause of all things, and for Pythagoras and his followers, numbers meant integers. Hippasus’ discovery of irrational numbers appeared to undermine the very core of Pythagoras’ teachings about the numerical nature of the universe. The secret could not get out. Hippasus had to die.

Imaginary engraving of the philosopher Hippasus of Metapontum. From the 1580 book Illustrium philosophorum et sapientum effigies ab eorum numistatibus extractae, by Girolamo Olgiati. Reprinted 1583.

The existence of irrational numbers became a Pythagorean secret. They were called “unutterables” because in Greek, the ratio between two integers was called logos, and so, irrational numbers were called, alogos, which can be translated as either “irrational” or “not spoken.” The worry caused by this secret knowledge was somewhat alleviated by Eudoxus of Cnidos (408-355 BC) when he argued that the basis of reality was a ratio of magnitudes. In effect, Eudoxus made geometry replace arithmetic as the highest mathematical discipline, the foundation of all others. Geometry and arithmetic were hardly even separate disciplines at the time. This change of emphasis allowed Pythagorean teachings about the numeric nature of the universe to continue.

Philosophia et septem artes liberales (Philosophy and the Seven Liberal Arts), as illustrated in the Hortus deliciarum. The order of the arts here are: grammar, rhetoric, dialectic, music, arithmetic, geometry, and astronomy. A more detailed study of this image can be found here and here.

         The idea that the mathematical disciplines have some orderly relationship between each other is essential for understanding the medieval concept of “quadrivium.” While it is well known that the medieval liberal arts curriculum, at least in its ideal established by Boethius, taught that a student must study both the trivium and quadrivium before progressing to philosophy and theology, the exact nature and rationale for the quadrivium is often less understood. Lists of the arts comprising the quadrivium (arithmetic, geometry, astronomy, and music/harmony) are consistent, but the exact order for these lists can vary. While there is no doubt that sometimes there is truly no rationale for a given order of the mathematical arts, attention to the mathematical art considered the principle or highest can reveal at least three identifiable streams of quadrivial traditions coming from the ancient world (similar to Chenu’s identification of different kinds of Platonism): the Boethian, the Calcidean, and the Capellan. The mathematical art considered “principle” is the one closest to metaphysical reality of the universe and serves as the foundation for all other mathematical disciplines. While the problem of irrational numbers may not have been on the forefront of anyone’s mind in the Middle Ages…it was a closely guarded Pythagorean secret after all…the problem of the principle mathematical art, inherited from Pythagoreanism, was readily available in the source texts.

This content is excerpted. Read the full article here at the University of Notre Dame’s Research Blog