The quadrivium refers to the four mathematical disciplines of arithmetic, geometry, astronomy, and music. Boethius was a key proponent of these sciences and wrote, or intended to write, textbooks for the study of each. The earliest known use of the term quadrivium is found in Boethius's text De Arithmetica. Although the grouping of the four mathematical disciplines is found earlier, notably in the fifth century Wedding of Philology and Mercury by Martianus Capella, Boethius not only adopted the term, but also infused the study of these disciplines with a greater moral and philosophical purpose. It was through the study of the quadrivium that one could reach an understanding of true knowledge. The following manuscripts illustrate the four disciplines of the quadrivium and the history of their study.