During the time of Muhammad and later in Middle Ages, Jewish writers commonly referred to Muhammad as ha-meshuggah ("the madman" or "possessed"), a title contemptuously used in the Hebrew Bible for impostors who think of themselves as prophets.
Christians were also often dismissive of Muhammad, with some producing highly critical accounts of his life. Some reports on Muhammad's life and death include claims circulated by Christian writers that Muhammad died while being drunk, or was killed by pigs. Such stories and opinions were circulated with the knowledge that Islam forbids both alcohol and pork. Such caricatures of Muhammad extended to works of literature and poetry. In Dante's Inferno, Muhammad and Ali are portrayed as being in Hell, subject to horrifying tortures and punishments for their sins of schism and sowing discord. In the Middle Ages Islam was widely believed to be a Christian heresy. In other works, he is described as a "renegade cardinal of the Catholic Church who decided to start his own false religion". A less belligerent depiction occurs in 13th century Estoire del Saint Grail, the first book in the vast Arthurian cycle, the Lancelot-Grail. Here, Muhammad is portrayed as a true prophet sent by God to bring Christianity to the pagan Middle East; however, his pride causes him to alter God's wishes and he deceives his followers, though his religion is viewed as vastly superior to paganism.
Martin Luther referred to Muhammad as "a devil and first-born child of Satan". Gottfried Leibniz, while praising Muhammad and his followers for spreading monotheism and "abolishing heathen superstitions" in the remote lands where Christianity had not been carried, held that belief in Muhammad, Zoroaster, Brahma, or Gautama Buddha is not as worthy as belief in Moses and Jesus.
In the early 20th century Western scholarly views of Muhammad changed, including critical views. In the 1911 Catholic Encyclopedia Gabriel Oussani states that Muhammad was inspired by an "imperfect understanding" of Judaism and Christianity, but that the views of Luther and those who call Muhammad a "wicked impostor", a "dastardly liar" and a "willful deceiver" are an "indiscriminate abuse" and are "unsupported by facts: Instead, nineteenth-century Western scholars such as Sprenger, Noldeke, Weil, Muir, Koelle, Grimme and Margoliouth give us a more correct and unbiased estimate of Muhammad's life and character, and substantially agree as to his motives, prophetic call, personal qualifications, and sincerity." Muir, Marcus Dods, and others have suggested that Muhammad was at first sincere but later became deceptive. Koelle finds "the key to the first period of Muhammad's life in Khadija, his first wife," after whose death he became prey to his "evil passions." Zwemer, a Christian missionary, criticised the life of Muhammad by the standards of the Old and New Testaments, by the pagan morality of his Arab compatriots, and last, by the new law which he brought. Quoting Johnstone, Zwemer concludes by claiming that his harsh judgment rests on evidence which "comes all from the lips and the pens of his [i.e. Muhammad's] own devoted adherents.
Scholar William Montgomery Watt says that there is no solid ground for the view of 19th century western scholars that Muhammad's character declined after Muhammad went to Medina. He argues that "in both Meccan and Medinan periods Muhammad's contemporaries looked on him as a good and upright man, and in the eyes of history he is a moral and social reformer."
In the 20th century non-scholars sometimes remained more critical. In 2002 Evangelical Christian leader Jerry Falwell called Muhammad "a terrorist," though he later apologized for the comment, saying that he had made a mistake when responding to a "controversial and loaded question. Contemporary critics have criticized Muhammad for preaching beliefs that are incompatible with democracy; Dutch feminist writer Ayaan Hirsi Ali has called him a "tyrant" and a "pervert". American historial Daniel Pipes sees Muhammad as a politician, stating that "because Muhammad created a new community, the religion that was its raison d'etre had to meet the political needs of its adherents.
The age of Aisha is cited by some critics who denounce Muhammad for having sexual relations with her. American Baptist pastor Jerry Vines called him a "demon-possessed pedophile". Jewish leaders and mainstream Protestant groups joined Muslims in denouncing the comments made by Vines. Abraham Foxman from the Anti-Defamation League described Vines' comments as "deplorable", adding that they were "not surprising coming from the leadership of the Southern Baptist Convention, which has a track record of denigrating and delegitimizing other religions."
Colin Turner, a professor of Persian language and Islamic history, states that Muhammad's marriage, in its historical context, would not have been considered the least improper. Such marriages between an older man and a young girl were customary among Bedouins. Turner further writes that Arabs in the 7th century tended to reach adulthood at an earlier age.
Muhammad has been often criticized in West for his treatment of the Jewish tribes of Medina. Moroccan author Abdelhamid Assassi writes: "At first, Muhammad used to pray in the direction of Jerusalem, in order to seek the sympathy and support of the Jews in the Peninsula, who carried great economic and social weight. Then he traded the Jews' direction of prayer for that of the pagans, in order to rally the Arab tribes to his preaching. For this reason he later took revenge on the Jews by expelling them, slaughtering them, robbing them, and taking their women as wives. Fazlur Rahman rejects what he sees as exaggeration of the role of Medinan Jews on the development of Islam. He states that the original change of the direction of prayer from Kaaba to Jerusalem certainly did not happen on Muhammad's arrival to Medina so that it could be interpreted as an attempt to entice the Jews. Rahman argues that the change most likely occurred when Muslims, as a result of persecution, were not allowed to go to Kaaba for worship: The reason indicated in the Qur'an was to emphasize the distinction between Muslims and Pagans. If the idea was to keep the Jerusalem as the qibla permanently, Rahman says, Jerusalem could have been religiously disassociated from the Jewish claims (similar to what the Qur'an did with respect to religious figures such as Moses and Abraham).
Muhammad is also criticised for the death of the men of Banu Qurayza, a Jewish tribe of Medina. The tribe was accused of having engaged in treasonous agreements with the enemies besieging Medina in the Battle of the Trench in 627. Ibn Ishaq writes that Muhammad approved the beheading of some 600-900 individuals who surrendered unconditionally after a siege that lasted several weeks. (Also see Bukhari ) (Yusuf Ali notes that the Qur'an discusses this battle in verses ). The women and children were sold into slavery. According to Norman Stillman, the incident cannot be judged by present-day moral standards. Citing Deut. 20:13-14 as an example, Stillman states that the slaughter of adult males and the enslavement of women and children, though bitter, was common practice throughout the ancient world. According to Rudi Paret, the adverse public opinion was more a point of concern to Muhammad when he had some date palms cut down during a siege than after this incident. Esposito also argues that in Muhammad's time traitors were executed and alleging similar situations in the Bible. Esposito says that Muhammad's motivation was political rather than racial or theological; he was trying to establish Muslim dominance and rule in Arabia.
A few Muslim scholars, such as W. N. Arafat and Barakat Ahmad, have disputed the historicity of the incident. Ahmad, argues that only the leaders of the tribe were killed. (see his thesis) Arafat argued that Ibn Ishaq gathered information from descendants of the Qurayza Jews, who embellished or manufactured the details of the incident. Watt finds Arafat's arguments "not entirely convincing."
Muhammad is criticized for apparently having had a child by a slave girl called Maria or Mariyah, who was a present from the Byzantine ruler of Egypt. By some accounts Muhammad did not marry her because she would not convert to Islam.
However, some defend Muhammad by arguing he treated slaves fairly. For example, there was a slave called Zayd ibn Harithah, whom Muhammad freed and adopted. Zayd later became a trusted companion to Muhammad. One early biography relates Muhammad as having said that "he (Zayd b. Harithah) was one of the dearest to me of all men.
According to Temkin, the first attribution of epileptic seizures to Muhammad comes from the 8th century Byzantine historian Theophanes who wrote that Muhammad’s wife "was very much grieved that she, being of noble descent, was tied to such a man, who was not only poor but epileptic as well." In the Middle ages, the general perception of those who suffered epilepsy was an unclean and incurable wretch who might be possessed by the Devil. The political hostility between Islam and Christianity contributed to the continuation of the accusation of epilepsy throughout the Middle ages. In 1967, The Christian minister, Archdeacon Humphrey Prideux gave the following description of Muhammad's visions:
He pretended to receive all his revelations from the Angel Gabriel, and that he was sent from God of purpose to deliver them unto him. And whereas he was subject to the falling-sickness, whenever the fit was upon him, he pretended it to be a Trance, and that the Angel Gabriel was come from God with some Revelations unto him.
Prideux, Frank R. Freemon says, thinks Muhammad had "conscious control over the course of the spells and can pretend to be in a religious trance. He sees epilepsy as related to malingering." During the nineteenth century, as Islam was no longer a political or military threat to Western society, and the views regarding epilepsy was changed, the theological and moral associations with epilepsy was removed; epilepsy was now viewed as a medical disorder. Nineteenth century orientalist, D. S. Margoliouth claims that Muhammad suffered from epilepsy and even occasionally faked it for effect. Sprenger attributes Muhammad's revelations to epileptic fits or a "paroxysm of cataleptic insanity." The most famous epileptic of the 19th century, Fyodor Dostoevsky (d.1881) wrote that epileptic attacks have an inspirational quality; he said they are “a supreme exaltation of emotional subjectivity” in which time stands still. Dostoevski claimed that his own attacks were similar to those of Muhammad: "Probably it was of such an instant, that the epileptic Mahomet was speaking when he said that he had visited all the dwelling places of Allah within a shorter time than it took for his pitcher full of water to empty itself." In an essay that discusses views of Muhammad's psychology, Franz Bul (1903) is said to have observed that "hysterical natures find unusual difficulty and often complete inability to distinguish the false from the true", and to have thought this to be the "the safest way to interpret the strange inconsistencies in the life of the Prophet." In the same essay Duncan Black Macdonald (1911) is credited with the opinion that "fruitful investigation of the Prophet's life (should) proceed upon the assumption that he was fundamentally a pathological case.
Modern western scholars of Islam have rejected the diagnosis of epilepsy. Tor Andrae rejects the idea that the inspired state is pathological attributing it to a scientifically superficial and hasty theory arguing that those who consider Muhammad epileptic should consider all types of semi-conscious and trance-like states, occasional loss of consciousness, and similar conditions as epileptic attacks. Andrae writes that "[i]f epilepsy is to denote only those severe attacks which involve serious consequences for the physical and mental health, then the statement that Mohammad suffered from epilepsy must be emphatically rejected." Caesar Farah suggests that "[t]hese insinuations resulted from the 19th-century infatuation with scientifically superficial theories of medical psychology. Noth, in the Encyclopedia of Islam, states that such accusations were a typical feature of medieval European Christian polemic. Maxime Rodinson says that it is most probable that Muhammad's conditions was basically of the same kind as that found in many mystics rather than epilepsy. Fazlur Rahman refutes epileptic fits for the following reasons: Muhammad's condition begins with his career at the age of 40; according to the tradition seizures are invariably associated with the revelation and never occur by itself. Lastly, a sophisticated society like the Meccan or Medinese would have identified epilepsy clearly and definitely. William Montgomery Watt also disagrees with the epilepsy diagnosis, saying that "there are no real grounds for such a view." Elaborating, he says that "epilepsy leads to physical and mental degeneration, and there are no signs of that in Muhammad." He then goes further and states that Muhammad was psychologically sound in general: "he (Muhammad) was clearly in full possession of his faculties to the very end of his life." Watt concludes by stating "It is incredible that a person subject to epilepsy, or hysteria, or even ungovernable fits of emotion, could have been the active leader of military expeditions, or the cool far-seeing guide of a city-state and a growing religious community; but all this we know Muhammad to have been."
Frank R. Freemon (1976) thinks that the above reasons given by Modern biographers of Muhammad in rejection of epilepsy come from the widespread misconceptions about the various types of epilepsy. In his differential diagnosis, Freemon rejects schizophrenic hallucinations, drug-induced mental changes such as might occur after eating plants containing hallucinogenic materials , transient ischemic attacks , hypoglycemia , labyrinthitis, Ménière’s disease, or other inner ear maladies . At the end, Freemon argues that if one were forced to make a diagnosis psychomotor seizures of temporal lobe epilepsy would be the most tenable one, although our lack of scientific as well as historical knowledge makes unequivocal decision impossible. Freemon cites evidences supporting and opposing this diagnosis. In the end, Freemon points out that a medical diagnosis should not ignore Muhammad’s moral message because it is just as likely, perhaps more likely, for God communicate with a person in an abnormal state of mind. From a Muslim point of view, Freemon says, Muhammed’s mental state at the time of revelation was unique and is not therefore amenable to medical or scientific discourse. In reaction to Freemon's article, GM. S. Megahed, a Muslim neurologist criticized the article arguing that there are no scientific explanations for many religious phenomena, and that if Muhammad's message is a result of psychomotor seizures, then on the same basis Moses's and Jesus's message would be the result of psychomotor seizures. In response, Freemon attributed such negative reactions to his article to the general misconceptions about epilepsy as a demeaning condition. Freemon said that he did have the plan to write an article on the inspirational spells of St. Paul, but the existence of such misconceptions cancels his plan.
William Muir, a 19th century scholar, like many other 19th century scholars divides Muhammad's life into two periods — Meccan and Medinan. He asserts that "in the Meccan period of [Muhammad's] life there certainly can be traced no personal ends or unworthy motives," painting him as a man of good faith and a genuine reformer. However, that all changed after the Hijra, according to Muir. "There [in Medina] temporal power, aggrandisement, and self-gratification mingled rapidly with the grand object of the Prophet's life, and they were sought and attained by just the same instrumentality." From that point on, he accuses Muhammad of manufacturing "messages from heaven" in order to justify a lust for women and reprisals against enemies, among other sins. D. S. Margoliouth, another 19th century scholar, sees Muhammad as a charlatan who beguiled his followers with techniques like those used by fraudulent mediums today. He has expressed a view that Muhammad faked his religious sincerity, playing the part of a messenger from God like a man in a play, adjusting his performances to create an illusion of spirituality. Margoliouth is especially critical of the character of Muhammad as revealed in Ibn Ishaq's famous biography, which he holds as especially telling because Muslims cannot dismiss it as the writings of an enemy:
In order to gain his ends he (Muhammad) recoils from no expedient, and he approves of similar unscrupulousness on the part of his adherents, when exercised in his interest. He profits utmost from the chivalry of the Meccans, but rarely requites it with the like... For whatever he does he is prepared to plead the express authorization of the deity. It is, however, impossible to find any doctrine which he is not prepared to abandon in order to secure a political end.Late 20th century
According to Watt and Richard Bell, recent writers have generally dismissed the idea that Muhammad deliberately deceived his followers, arguing that Muhammad “was absolutely sincere and acted in complete good faith”. Modern secular historians generally decline to address the question of whether the messages Muhammad reported being revealed to him were from "his unconscious, the collective unconscious functioning in him, or from some divine source", but they acknowledge that the material came from "beyond his conscious mind. Watt says that sincerity does not directly imply correctness: In contemporary terms, Muhammad might have mistaken for divine revelation his own unconscious. William Montgomery Watt states:
Only a profound belief in himself and his mission explains Muhammad's readiness to endure hardship and persecution during the Meccan period when from a secular point of view there was no prospect of success. Without sincerity how could he have won the allegiance and even devotion of men of strong and upright character like Abu-Bakr and 'Umar ? ... There is thus a strong case for holding that Muhammad was sincere. If in some respects he was mistaken, his mistakes were not due to deliberate lying or imposture ....the important point is that the message was not the product of Muhammad's conscious mind. He believed that he could easily distinguish between his own thinking and these revelations. His sincerity in this belief must be accepted by the modern historian, for this alone makes credible the development of a great religion. The further question, however, whether the messages came from Muhammad's unconscious, or the collective unconscious functioning in him, or from some divine source, is beyond the competence of the historian.
Rudi Paret agrees, writing that "Muhammad was not a deceptor, and Welch also holds that "the really powerful factor in Muhammad’s life and the essential clue to his extraordinary success was his unshakable belief from beginning to end that he had been called by God. A conviction such as this, which, once firmly established, does not admit of the slightest doubt, exercises an incalculable influence on others. The certainty with which he came forward as the executor of God’s will gave his words and ordinances an authority that proved finally compelling.
Bernard Lewis, another modern historian, commenting on the common western Medieval view of Muhammad as a self-seeking impostor, states that
The modern historian will not readily believe that so great and significant a movement was started by a self-seeking impostor. Nor will he be satisfied with a purely supernatural explanation, whether it postulates aid of divine of diabolical origin; rather, like Gibbon, will he seek 'with becoming submission, to ask not indeed what were the first, but what were the secondary causes of the rapid growth' of the new faith
Watt rejects the idea of Muhammad's moral failures from Meccan period to Medinian one and contends that such views has no solid grounds. He argues that "it is based on too facile a use of the principle that all power corrupts and absolute power corrupts absolutely". Watt interprets incidents in the Medinan period in such a way that they mark "no failure in Muhammad to live to his ideals and no lapse from his moral principles."