A key work for research on the arts of the High Middle Ages is a book handed down under the pseudonym Theophilus Presbyter titled Schedula diversarum atrium (On Divers Arts), which furnishes a reflection on the artes mechanicae together with a comprehensive overview of all aspects of knowledge. Included in this work is a review of the textual history of the Schedula diversarum atrium as well as new hypotheses on the identity of its author.