Chapter 5 reviews the debate within Christian apologetic and Western scholarly publications over whether Islam’s founder Muhammad was epileptic. Islam’s territorial and religious challenges to Christianity motivated Christian writers to discredit the prophet and his visions, and around the year 815 C.E., the Byzantine monk Theophanes wrote that Muhammad’s revelations were epileptic fits rather than godly revelations. Polemical attacks of this nature appeared in European religious literature throughout the Middle Ages and into the early modern era. Challenges, however, to this epileptic interpretation appeared by the early eighteenth century, but in the mid-nineteenth century, linguistic scholar Gustav Weil used Islamic texts to argue that in fact Muhammad had been epileptic. In 1873, English psychiatrist James Howden referred to the “strong evidence” in favor of Muhammad’s epileptic interpretation, and in doing so introduced the diagnosis into Western psychiatric discourse. Islamic specialists and psychiatrists in the twentieth century divided over the issue, but a 1976 article by Frank Freemon cautiously concluded that Muhammad had epileptic seizures, which then became the established (but not universally accepted) interpretation in English language psychiatric literature. Among Islamists and some psychiatrists into the twenty-first century, opinions continue to differ on Muhammad’s epilepsy question.