Criticism of Muhammad

The first to criticize the Islamic prophet Muhammad were his non-Muslim Arab contemporaries, who decried him for preaching monotheism, and the Jewish tribes of Arabia, for what they claimed were unwarranted appropriation of Biblical narratives and figures and vituperation of the Jewish faith. For these reasons, medieval Jewish writers commonly referred to him by the derogatory nickname ha-Meshuggah (Hebrew: מְשֻׁגָּע‬, "the Madman" or "the Possessed").

During the Middle Ages, various Western and Byzantine Christian polemicists considered Muhammad to be a false prophet, the Antichrist, a heretic, Satan possessed by demons, a sexual deviant, a polygamist, and a charlatan. Thomas Aquinas criticized Muhammad's handling of doctrinal matters and promises of what Aquinas described as "carnal pleasure" in the afterlife.

Modern criticism by some Western scholars has raised questions about Muhammad’s prophetic claims, personal conduct, marriages, slave ownership, and mental state. Criticism has also focused on his treatment of enemy captives, particularly the case of mass killing of men of the Banu Qurayza tribe in Medina. Muslim scholars often respond by emphasizing the historical context of 7th-century Arabia and Muhammad’s role in promoting justice and social reform. Some historians say the punishment of the Banu Qurayza reflected the norms of the time and was ordered by Sa'd ibn Mu'adh, though others question Muhammad’s role or the scale of the event.

Points of contention

Ownership of slaves

According to sociologist Rodney Stark, "the fundamental problem facing Muslim theologians vis-à-vis the morality of slavery" is that Muhammad himself engaged in activities such as purchasing, selling, and owning slaves, and that his followers saw him as the perfect example to emulate. Stark contrasts Islam with Christianity, writing that Christian theologians wouldn't have been able to "work their way around the biblical acceptance of slavery" if Jesus had owned slaves, as Muhammad did.