The present study explores the ways in which competing frameworks of knowledge sought to order society in early Islamic Mesopotamia (60–193 AH/680–809 CE). This research examines the conditions under which two frameworks of knowledge came into being; how they tried to maximize their power through forging alliance with the caliphate; how they established the legitimacy of their knowledge; and how they promoted their visions of social order. The first framework of knowledge is associated with the secretaries, as state bureaucrats, who helped transfer ancient administrative methods and practices to the emerging Islamic polity. Their immense assistance in tackling manifold problems of the Umayyad and Abbasid caliphates consisted not only in offering technical know-how, useful administrative practices, expertise, and political wisdom, but also in addressing the foundational problems of the polity. This research argues that the secretaries' solution to the caliphate's structural problems—particularly the crisis of legitimacy—might have run counter to the social order promoted by Muslim religious scholars (the 'ulamā'). The secretaries' framework of knowledge and its concomitant social order, then, posed a threat to the authority of the 'ulamā' who pursued an alternative framework of knowledge rooted in sacred sources of law. Delving into a number of treatises composed and/or translated by the champions of these knowledge frameworks (e.g., ‘Abd al-Ḥamīd b. Yaḥyā, Ibn al-Muqaffa‘, and Abū Yūsuf), this dissertation concludes that the validation of knowledge and expertise involved more than solving specific problems such as maximizing the government revenues and efficiently collecting taxes from subjects; it rather relied on the ability of knowledge and expertise to offer solutions to the problem of social and political order.