The Greeks “systematized...

The Greeks “systematized, generalized, and theorized,” but the accumulation of positive knowledge based on patient, detailed, and prolonged observation was altogether “alien to their temperament.” This weakness of the Greek genius was removed by a rather practical and penetrating mind of the Muslims,[^5] who classified ethics as a “part of practical philosophy.” With ibn Miskawaih, the first Muslim moralist, the emphasis shifted from broad generalizations to individual differentiation and specification of virtues.

He not only determined seven, 11, 12 and 19 species[^6] of wisdom, courage, temperance, and justice respectively – the four cardinal virtues of Plato – but also developed an attractive theory of the causes and cures of mental diseases, a process which culminated in al-Ghazālī with a shift from an intellectual to a mystic outlook.[^7] Ibn Miskawaih had worked out the details of Plato’s theory of virtue, but with Tusi the problem was that of improving and completing the Aristotelian theory of vice.

He emphasized for the first time that deviation from the equipoise is not only quantitative but also qualitative, and, thus, added perversion (rada’at) as the third generic cause of vice[^8] to the Aristotelian excess and deficiency of a state. Tusi also…