Standard histories of Western medicine survey the Latin European appropriation of Arabic texts, and focus on works that impacted the development of Latin Western medicine: the Greek works in Arabic translation, and the systematization of Greek knowledge by Rhazes and Avicenna. They generate the false impression that there were no further developments in medicine in the Islamic world after Avicenna. This chapter sketches Avicenna’s contribution to ancient disputes on the nature of the female contribution, the make-up of seminal matter, the role played by the male semen, and the formation of the fetus, while locating his understanding of generation within his larger philosophical and theological system and the intellectual contexts of medieval Islamic societies. It then charts post-Avicennan, Mamluk-era medical debates on generation in the Islamic world, especially on the physiology of generation and notions of ensoulment in commentaries on Avicenna’s Canon of Medicine by Ibn al-Nafīs and his students. It demonstrates that the fourteenth-century Islamic religious discussions on generation and ensoulment were in direct conversation with these post-Avicennan debates, and brought these ideas to broader audiences. The possibility that Renaissance physicians appropriated ideas about generation from post-Avicennan commentaries is also considered.