Letter-magic and 'extremist' Sufism in high medieval Egypt: Ibn Khaldun, Ibn 'Arabi, and Ahmad al-Buni In his discussion of letter-magic (simiya) in the Muqaddimah, Ibn Khaldun names Ibn 'Arabi (560/1165-638/1240) and Ahmad al-Buni (d. 622/1225) as the leading theorists of this art, and 'extremist' Sufis (al-ghulat min al-mutasawwifah) as its practitioners. Modern scholars have had surprisingly little to say about Ibn Khaldun's close association of the great mystical philosopher Ibn 'Arabi with al-Buni, who primarily has been associated with talismans and other 'popular' occult practices, and whose importance in Islamic thought largely has been dismissed. Through a close reading of al-Buni's _Lata'if al-isharat fi 'ilm al-huruf al-'alawiyah_, selected writings of Ibn 'Arabi and his intellectual descendant Muhammad b. Ahmad al-Farghani (d. 700/1300-1301), and Ibn Khaldun's critiques of simiya and Akbarian (i.e. Ibn 'Arabi-derived) Sufism, this paper argues that al-Buni and Ibn 'Arabi and his students drew upon a shared, distinctive pool of cosmological concepts and metaphors that indicates origins in common. Based on these texts and on transmission data preserved in the margins of some Mamluk-era manuscripts of Lata'if al-isharat, this paper further argues that, at least through the Mamluk period, knowledge of Bunian letter-magic and of Akbarian writings and practices moved through shared social networks. Although al-Buni is one of the most famous Muslim occultists, and although Lata'if al-isharat fi 'ilm al-huruf al-'alawiyah survives in multiple early manuscript copies and is one of the most theoretically explicit and detailed of Islamic magical works, the text has never been given an extended scholarly treatment. The majority of modern scholars who have discussed al-Buni have dealt almost exclusively with late manuscripts and printed editions of a work called Shams al-ma'arif al-kubra, a text which even casual examination reveals as having been produced in the Ottoman period and beyond, and as having been heavily interpolated with extraneous materials. This paper is one of the first products of a larger attempt to systematically explore the earliest strata (Ayyubid and Mamluk-era manuscripts only) of the Bunian corpus and the social networks in which it circulated. This talk should be of interest to historians of Islamic knowledge production, medieval Cairo, Sufism, Islamic magic, Ibn 'Arabi, and Ibn Khaldun.