Martianus Capella (fl. 450), De nuptijs philologie [et] Mercurij (Vicenza, 1499), 1st printed ed. “On the Marriage of Philology and Mercury.”
Capella described the seven liberal arts. The first three are grammar, logic or dialectic, and rhetoric. Then come the mathematical sciences, geometry and arithmetic. Geometrical circles in motion make astronomy. Numbers in motion make music.
Capella also argued that Venus and Mercury revolve around the Sun. Capella’s cosmic system was consistent with Galileo’s later discovery of the phases of Venus.
Mathematics in the Liberal Arts Tradition
The strange title, The Marriage of Philology and Mercury, refers to a wedding of the swiftest god and the most learned goddess. Its meaning is the joining of speech and insight, as if our thoughts and language were as agile as a spherule of mercury rolling around on a sheet of glass.
| Quadrivium | Numbers | Magnitudes |
| Entities | Arithmetic | Geometry |
| Entities in motion | Music | Astronomy |
Capella (5th century C.E.) described the seven liberal arts, i.e., the education appropriate to a free citizen rather than a slave.
According to the opening page, the first three liberal arts are grammar, how to write well; logic or dialectic, how to think well; and rhetoric, how to speak well. These three became known as the trivium.
Next come the last four liberal arts, the quadrivium. These are all mathematical sciences, beginning with geometry, the study of magnitudes, like lines and circles; and arithmetic, the study of numbers. If magnitudes are put in motion, we then have astronomy, a branch of geometry. If numbers are put in motion, we then have music, a branch of arithmetic. So music and astronomy, for the liberal arts tradition as for the ancient Pythagoreans, are sister sciences.
