In some cases, Islamist extremists despise paintings, photos and movies representing the Prophet Muhammad, although the Koran does not clearly ban such images. The Muslim holy book does state that God created humans and all other living beings, adding that even if humans were to attempt to reproduce living creatures, they would never be able to breathe life into them.

Rudi Paret, an Islam expert from Tübingen University and translator of the authoritative German version of the Koran, explains that a "ban on images" appears much later, in the hadith literature. Hadiths - there are an estimated 100,000 in the canon - collect reported sayings and traditions from the Prophet Muhammad. In these texts, some passages are critical or even hostile towards pictures.

In fiqh, the Islamic jurisprudence, there is also a debate surrounding picture bans. A reference often used in the discussion comes from hadith author al-Bukhari, who attributes this aphorism to Muhammad: "I have heard the Messenger of God say, 'Angels do not enter a house in which there is a dog or a picture.'" Did the Prophet fear that humans wanted to "imitate God" through representations of living beings? Dogs are considered impure in Islam, as are icons representing idols. Therefore, one should not pray in a room with images.

No ban on images in Islam

There is nevertheless no clear ban on images written in the hadiths published up to 200 or 300 years after the death of Muhammad. Like the Koran itself, the hadith texts do not convey a uniform message, as chapters added later on complement, correct or replace earlier ones. Islamic scholars still have heated debates surrounding the authenticity and the theological meaning of these texts.

The fear is that images may become the subject of worship, rather than God himself. It was likely for this reason that Muhammad required all idols to be removed from the Kaaba when he triumphantly entered Mecca in 630 AD. The Kaaba was already a pre-Islamic holy site, but through this action it became the central shrine of Islam. No more space would be dedicated to other gods in this building. According to the Swiss Islam expert Silvia Naef, the aim was to get rid of the idolatry of the pre-Islamic Arabs in order to replace it with this monotheistic faith.

Can the Mecca iconoclasm of the time explain the apprehension regarding the power of images that still exists? In Sunni Islam, figural representations were indeed prohibited to a large extent. But not all Muslims oppose religious icons and Islamic paintings do exist. Illustrations and miniatures in books depict the Prophet Muhammad and his mother Amina, both with and without a veil covering her face. Ibrahim was also represented, as were other figures mentioned in the Koran. Persian book illustrations depicting religious and secular subjects blossomed, just like the miniatures painted by the Mughals, a Muslim culture in 16th- and 17th-century India.

The invention of photography and television in the 19th and 20th centuries has further fueled the Islamic debate on the representation of living beings.

Christian conflicts

A similar controversy, however, persists in Christianity as well. "The Old Testament expressly prohibits representations of God," recalls the Islam expert Naef. The Byzantine interpretation of the Second Commandment - "Thou shalt not make unto thee any graven image" - led to iconoclasm periods in the eight and ninth centuries. A focal point of the dispute at the time was whether it was acceptable to depict Jesus and the Virgin Mary. The Eastern Orthodox Church eventually determined that it was appropriate to do so, and a rich tradition of icon painting emerged.

Further western churches feared that pictures could lead to idolatry. But around the year 600 AD, Pope Gregory the Great spoke out against iconoclasm, while warning against the excessive veneration of images. He saw an educational value in images depicting Christianity. The Frankfurt Council argued similarly in 794. In the 12th and 13th centuries, the Catholic Church accepted such images unconditionally. Then the Church Reform in the 16th century led once again to iconoclasm: Reformers Calvin and Zwingli banished imagery from their churches. Martin Luther warned that images could "promote blasphemy and cause loss of faith."

This rejection of visual depictions in the history of religion protected early monotheism. All three Abrahamic religions - Judaism, Christianity and Islam - feared the wrath of God if they did not apply it. At the same time, many events occurred which undermined it. Nowadays, extremists claim to be rectifying this in the name of Allah, stirring up hatred in response to drawings of the Prophet.

As art historian Horst Bredekamp said in an interview with the German daily "Süddeutsche Zeitung," "killing people because of illustrations, as happened in Paris, is the political strategy of Islamist groups who do not want to distinguish between image and God.