 Following Martianus Capella’s (fl. c. 410) The Marriage of Philology and Mercury, medieval thinkers classified music as one of the liberal arts. These were divided into the arts of the trivium (grammar, logic and rhetoric) and the quadrivium (arithmetic, geometry, astronomy and music). The arts of the trivium were referred to as artes sermocinales, because they are related to discourse and language. The arts of the quadrivium were instead the artes reales, studying the mathematical and physical constitution of the universe. The classification of music as one of the artes reales is unsurprising in light of the Pythagorean-Boethian view of music as primarily concerned with proportions and harmony.