Abstract

Originally introduced by Plato and Aristotle, the doctrine of the mean is the most prevalent theory of ethics among Islamic scholars. According to this doctrine, every virtue or excellence of character lies in the observance of the mean, whereas vices are the excess or deficiency of the soul in his functions. Islamic scholars have been influenced by the doctrine, but they have also developed and re-conceptualized it in innovative ways. Kindi, Miskawayh, Avicenna, Raghib Isfahani, Nasir al-Din Tusi, and others are among the Islamic contributors to the subject. Some of their contributions are as follows: bringing together Aristotle's doctrine of the mean with Plato's psychology, dividing virtues into four higher geniuses, dividing vices into eight higher geniuses, setting various kinds of vices and virtues under these higher geniuses, adding the criteria of quality to Aristotle's quantitative evaluation of excess and deficiency, dividing various conceptualizations of justice, adding religious and mystical virtues into the existing list of virtues, and proposing a comprehensive model for curing diseases of the soul.