Although systems of higher education date back to ancient Greece, ancient Rome and ancient China, the concept of "postgraduate" education depends upon the system of awarding degrees at different levels of study, and can be traced to the workings of European medieval universities, mostly Italians. University studies took six years for a bachelor's degree and up to twelve additional years for a master's degree or doctorate. The first six years taught the faculty of the arts, which was the study of the seven liberal arts: arithmetic, geometry, astronomy, music theory, grammar, logic, and rhetoric. The main emphasis was on logic. Once a Bachelor of Arts degree had been obtained, the student could choose one of three faculties—law, medicine, or theology—in which to pursue master's or doctor's degrees.