Sa'd ibn Mansur Ibn Kammuna (died 1284) was a 13th Century Jewish physician

Physician

A physician is a health care provider who practices the profession of medicine, which is concerned with promoting, maintaining or restoring human health through the study, diagnosis, and treatment of disease, injury and other physical and mental impairments...

 (ophthalmologist

Ophthalmology

Ophthalmology is the branch of medicine that deals with the anatomy, physiology and diseases of the eye. An ophthalmologist is a specialist in medical and surgical eye problems...

), philosopher and critic

Critic

A critic is anyone who expresses a value judgement. Informally, criticism is a common aspect of all human expression and need not necessarily imply skilled or accurate expressions of judgement. Critical judgements, good or bad, may be positive , negative , or balanced...

 of Islam

Criticism of Islam

Criticism of Islam has existed since Islam's formative stages. Early written criticism came from Christians, prior to the ninth century, many of whom viewed Islam as a radical Christian heresy...

 who lived under the rule of the Mongols

Mongols

Mongols ) are a Central-East Asian ethnic group that lives mainly in the countries of Mongolia, China, and Russia. In China, ethnic Mongols can be found mainly in the central north region of China such as Inner Mongolia...

 in Baghdad

Baghdad

Baghdad is the capital of Iraq, as well as the coterminous Baghdad Governorate. The population of Baghdad in 2011 is approximately 7,216,040...

.

As a prolific scholar he played an important role in the diffusion of new thought in the Middle East

Middle East

The Middle East is a region that encompasses Western Asia and Northern Africa. It is often used as a synonym for Near East, in opposition to Far East...

. Much of his legacy, contained in the form of commentaries, correspondence, and treatise still survives today and makes up part of the historical remnants of his time.

Works

Ibn Kammuna's commentary on Shahab al-Din Suhrawardi's

Shahab al-Din Suhrawardi

Other important Muslim mystics carry the name Suhrawardi, particularly Abu 'l-Najib al-Suhrawardi and his paternal nephew Abu Hafs Umar al-Suhrawardi."Shahāb ad-Dīn" Yahya ibn Habash as-Suhrawardī was a Persian...

 Talwihat, the core text of Illuminationist philosophy is deemed as one of the most thorough examination of that branch of thought.

His comparative treatise on the three monotheistic religions Christianity

Christianity

Christianity is a monotheistic religion based on the life and teachings of Jesus as presented in canonical gospels and other New Testament writings...

, Judaism

Judaism

Judaism ) is the "religion, philosophy, and way of life" of the Jewish people...

 and Islam

Islam

Islam . The most common are and .   : Arabic pronunciation varies regionally. The first vowel ranges from ~~. The second vowel ranges from ~~~...

, titled Examination of the Three Faiths challenged the legitimacy of Islam where he reasoned that incompatibility of sharia

Sharia

Sharia law, is the moral code and religious law of Islam. Sharia is derived from two primary sources of Islamic law: the precepts set forth in the Quran, and the example set by the Islamic prophet Muhammad in the Sunnah. Fiqh jurisprudence interprets and extends the application of sharia to...

 with the principles of justice undercuts Muhammad's claims of being a perfect man and stated that people convert to Islam from ulterior motives.

"That is why, to this day we never see anyone converting to Islam unless in terror, or in quest of power, or to avoid heavy taxation, or to escape humiliation, or if taken prisoner, or because of infatuation with a Muslim woman, or for some similar reason. Nor do we see a respected, wealthy, and pious non-Muslim well versed in both his faith and that of Islam, going over to the Islamic faith without some of the aforementioned or similar motives."

He goes on to regard the Prophet Muhammad "unoriginal" and "imperfect".

"We will not concede that Muhammad added to the knowledge of God and of obedience to him anything more than what was found in the earlier religions."

"There is no proof that Muhammad attained perfection and the ability to perfect others as claimed."

The publication of the book caused rioting in Baghdad

Baghdad

Baghdad is the capital of Iraq, as well as the coterminous Baghdad Governorate. The population of Baghdad in 2011 is approximately 7,216,040...

, forcing Ibn Kammuna to flee that city in secret and was recorded by the thirteenth century historian Ibn al-Fuwati.

"In this year 1284 it became known in Baghdad

Baghdad

Baghdad is the capital of Iraq, as well as the coterminous Baghdad Governorate. The population of Baghdad in 2011 is approximately 7,216,040...

 that the Jew Ibn Kammuna had written a volume in which he displayed impudence in the discussion of the prophecies. God keep us from repeating what he said. The infuriated mob rioted, and massed to attack his house and to kill him. The amir...and a group of high officials rode forth to the Mustansiriya madrassa, and summoned the supreme judge and the law teachers to hold a hearing on the affair. They sought Ibn Kammuna but he was in hiding. That day happened to be a Friday. The supreme judge set out for the prayer service but as the mob blocked him, he returned to the Mustansirya. The amir stepped out to calm the crowds but these showered abuse upon him and accused him of being on the side of Ibn Kammuna, and of defending him. Then, upon the amir’s

Emir

Emir , meaning "commander", "general", or "prince"; also transliterated as Amir, Aamir or Ameer) is a title of high office, used throughout the Muslim world...

order, ii was heralded in Baghdad that, early the following morning outside the city wall, lbn Kammuna would be burned. The mob subsided, and no further reference to Ibn Kammuna was made. As for lbn Kammuna, he was put into a leather-covered box and carried to Hilla where his son was then serving as official. There he stayed for a time until he died."