Doctors of the medieval Church were theologians of outstanding merit and saintliness. The original four were Gregory the Great, Ambrose, Augustine, and Jerome. In scholastic times outstanding teachers were also given doctoral epithets. Aquinas is the angelic doctor, Bonaventure the seraphic doctor, Roger Bacon the marvellous doctor, Duns Scotus the subtle doctor, Albert the Great the universal doctor, Bernard the mellifluous doctor.