This depiction of the seven liberal arts is taken from the manuscript Tübinger Hausbuch, a treatise on medicine and astrology (iatromathematical calendar) featuring numerous coloured ink drawings and compiled in the late middle ages. The arts are represented by symbols such as a set square (geometry, left) or a rod (grammar, centre). The "liberal" arts were so called because they were the preserve of "free" individuals, i.e. men who did not have to provide for their own income. They were defined in opposition to the Artes mechanicae or mechanical arts.
The seven liberal arts, from left to right: geometry, logic, artithmetic, grammar (centre), music, physics (instead of astronomy), rhetoric. Coloured ink drawing on paper, ca. 1430–1480, unknown artist; source: Tübinger Hausbuch: Iatromathematisches Kalenderbuch: die Kunst der Astronomie und Geomantie, Handschrift, ca. 1430–1480, Md. 2, 320v, digital copy Universitätsbibliothek Tübingen, http://idb.ub.uni-tuebingen.de/diglit/Md2/0643, CC-BY-SA 3.0 DE, http://creativecommons.org/licenses/by-sa/3.0/de/.