Why Do They Apostatize? Apostasy, Law, and Religious Argumentation in the Western Mediterranean (ca. 1200-1300)

In the Western Mediterranean, the relation between Christian and Muslim powers shifted drastically in the twelfth and thirteenth centuries. Militarily, the balance of power between the Christian kingdoms in the north of the Iberian Peninsula and the Muslim rulers in al-Andalus (Southern Iberia) and the Maghrib (North Africa) started to shift in favor of the Christians. Multiple successful campaigns, spread over a century and half, placed most of the Iberian Peninsula and the local Muslim populations under Christian control. Meanwhile, successive Berber dynasties in al-Andalus and the Magrib enacted social reforms which sought to promote the hegemony of first Maliki and then Almohad teachings. These changes also increased tax burdens and other oppressive measures against local dhimmi communities (non-Muslims permitted to live under Muslim Rule) which stressed the tenuous peace between these groups and the ruling Muslims. These reforms culminated in the Almohads forcibly converting many dhimmi groups. Intellectually, Muslim and Christian leaders simultaneously tried to address these social changes while also trying to apply new forms of rationalist argumentation to interreligious disputes. Interwoven into all these changes was an impetus to shift the religious demographics: convert members of the opposite religion and prevent the apostasy of coreligionists. This dissertation examines the concept of apostasy as it appears in Christian and Islamic legal and religious writing during this period. It investigates how authors of legal texts and religious polemics changed their understanding of the concept of apostasy in connection with their changing understanding of religious persuasion, and, correspondingly, how they adjusted their attempts to curb apostasy through normative social controls. Furthermore, it attempts to bring disparate sources into discussion. This study explores descriptions of apostasy to discern changes in the general understanding of the phenomenon over time and to clarify the distinctions between polemical and legal thinking about apostasy during the twelfth and thirteenth centuries. This exploration reveals a period in which the crisis of authority in religious argumentation drove both Christian and Muslim authors to newly acknowledge the potential for belief-driven apostasy and to reinforce social displays of religious affiliation. Both Christian and Muslim authors increasingly acknowledged the potential for rationalistic arguments to generate apostates. Moreover, these changes affected both legal and rhetorical responses to apostasy threats, which suggests an intimate connection between legislative and polemical conceptualizations of religious others.