Humanistic instruction comprised grammar, rhetoric, dialectics, arithmetic, geometry, music, and astronomy (trivium and quadrivium). To the higher instruction belonged dogmatic and moral theology, whose source was the Scriptures and the Patristic Fathers. It was completed by the study of Canon law. The School of Saint-Victor arose to rival those of Notre-Dame and Ste-Geneviève. It was founded by William of Champeaux when he withdrew to the Abbey of Saint-Victor. Its most famous professors are Hugh of St. Victor and Richard of St. Victor.