Shams al-D?n al-Dhahab? (1274-1352/3), the noted scholar of traditions and history, spent most of his life in Maml?k Cairo and Damascus. The bulk of his extant work pertains to the science of ?ad?th criticism and historical works such as ?abaq?t, his famous history of Islam, and various other works in the same genre. Dhahab? also authored a highly influential and interesting collection of major sins, kab?’ir, that attempts to compile the principle Quranic, Prophetic, and traditional reports describing the most serious sins a Muslim can commit. This collection is therefore extremely rich in anecdotal material that sheds light on medieval Muslim conceptions of justice, evil, and ethics; it is particularly illuminating for its discussions of sexual deviance, most importantly its sections on zin? (adultery or fornication) and liw?? (“sodomy”). These two sections contain a wealth of detail that can tell us much about how Dhahab? construes human sexuality in general. Through an interpretation of Dhahab?’s prohibitions of certain types of sexual activity, this paper will attempt to get at Dhahab?’s theory of sexuality and how it relates to other relevant social and intellectual discourses in the Maml?k period. Dhahab?’s discussion of male homoerotic desire is particularly instructive in this regard, as he suggests that male homoerotic desire is so pervasive that it was even felt by Quranic prophets and even the Prophet Mu?ammad himself. By closely analyzing Dhahab?’s discussion of male homoerotic sexual desire in particular, this paper will argue that Dhahab? proposes a theory of human sexuality based on the concept of desire (shahwa), a theory that is situated between what are characterized in modern debates as “constructionist” and “essentialist” theories of human sexuality. Dhahab?’s theory of sexuality therefore may suggest a level of complexity in pre-modern notions of sexuality that cannot be fully described in either totally essentialist or constructionist terms, and may instead move simultaneously within discursive categories constitutive of both of these dimensions.