Box 1. A long tradition

Seen in its historical context, the return of Islam to politics in countries with large Muslim populations is not surprising. It is a form of government that many experienced with few interruptions for nearly 1,400 years. Until the end of the First World War, most countries in the Middle East were provinces in the Ottoman Empire, and provincial governors applied variants of laws based on the Koran and on the life of the Prophet Muhammad.

The Ottoman Empire was the most recent incarnation of the Islamic caliphate, whose rule began shortly after Muhammad's death in the seventh century, spreading Islam and Islamic government into Africa, Asia, the Middle East, and eastern and southern Europe.

Islamic law (sometimes called sharia law) is based on two principal sources: the Koran and a record of Muhammad's daily life known as hadith. These are complemented by consensus among religious scholars, and independent reasoning by analogy. Among the Sunni and Shia schools of Islam, the latter gives more weight to reasoning and critical thinking, which goes some way to explain the differences between Shia Iran and Sunni Saudi Arabia in bioethics, for example. E.M.

 N. ISHTAYEH/AP/EMPICS