This dissertation analyzes gender constructions and notions of moral gender relations in three widely influential medieval Persian treatises of Islamic ethics (akhlaq), Kimiya-i Sa`adat by Abu Hamid Muhammad al-Ghazali (d. 1111), Akhlaq-i Nasiri by Nasir-ad Din Tusi (d. 1274), and Akhlaq-i Jalali by Jalal ad-Din Davani (d. 1502). In examining these prescriptive works that instruct Muslims on how to live ethical lives, the main question I ask is how have medieval Muslim ethicists constructed morally guided notions of masculinity, femininity, and marriage and male homosocial relations. I argue that these texts reveal a metaphysical tension between an ethical principle that all human selves (nafses) are created equal and a hierarchical organization of humanity based on intellect and spirituality, in which some men are above others based on ethical and rational capacity and all men are above women. The ethicists define ultimate masculinity in terms of power, intellectual potential, and ethical comportment in the domestic realm as well as in homosocial structures of court, civic, and community life. They define women as instrumental to men's ethical activities since they view women themselves as lacking full rationality and limited by their biological functions.