PARIS Sharia law is understood and applied in such varied ways across the Muslim world that it is difficult to say exactly what it is and how it could fit into a western legal context, according to experts on Islam.
Full Islamic criminal law, the harsh code most non-Muslims think of when they hear the word sharia, is applied in very few countries, such as Saudi Arabia. Islamic "personal law" for issues like marriage and inheritance is much more common.
Archbishop of Canterbury Rowan Williams sparked off a storm last week by suggesting Britain adopt some sharia law. British Muslims defending him stressed most of the Islamic world also rejected the ultra-orthodox model that he clearly ruled out.
"There are 57 Muslim countries in the world and only two or three of them impose full sharia criminal law. Why on earth would we want to have that here?" asked Sheikh Suhaib Hasan, secretary of the Islamic Sharia Council in Britain.
There are also widely differing interpretations of sharia, both within the four classical Sunni and one Shi'ite schools of jurisprudence and between traditional and modern thinkers.
"In the Muslim world these days, 'sharia' means a whole variety of different things," said John Voll, professor of Islamic history at Georgetown University in Washington.
Williams apparently had in mind a modern school of Muslim thinking that sees sharia as a system of essential Islamic values rather than a fixed code of harsh punishments, he said.
Most Muslim states limit the use of sharia to "personal law" on issues such as marriage, divorce, inheritance and child custody. Western critics say most Muslim personal law limits women's rights and introduces inequality before the law.
Egypt says sharia is the main source of its legislation but has penal and civil codes based mostly on 19th century French law. Hudoud, the corporal and capital punishment outlined in the Koran, has not been applied there in modern times.
Muslims cannot convert to other faiths and non-Muslims who convert to Islam are not supposed to leave it, but a court allowed this for 12 people in a landmark case last week.
Pakistan has a similar split between civil and penal codes carried over from the British colonial period and Muslim personal law. It also has a Federal Sharia Court to decide if laws passed by parliament conform to Islam.
Apart from a few public lashings since Islamisation started in the 1980s, harsh physical punishments have not been imposed. Nobody has been executed under a law banning blasphemy against Islam, but some accused blasphemers have been killed by mobs.
Lebanon has 18 recognized religious denominations among its Muslims, Christians and Druze and all have religious courts for personal law and civil courts for everything else.
In India, Hindus, Muslims, Sikhs, Jains and followers of other faiths can decide whether they want to be bound by secular personal law or their own religious code.
Indonesia is the world's largest Muslim nation and quite moderate in Islamic terms. Its western province of Aceh uses sharia law as part of a local autonomy deal granted by Jakarta and people have been caned for adultery, gambling and stealing.
Nigeria's northern states adopted a harsh sharia code in 2000, but punishments have been rare. A woman convicted of adultery, Amina Laval, was freed on appeal after her sentence of stoning to death caused an international uproar.
About a dozen other women convicted of adultery have also been freed on appeal.
In contrast to this traditional jurisdiction, modern Muslim scholars such as Swiss-born Tariq Ramadan interpret sharia more broadly as "the expression of the universal principles of Islam" and a way of thinking that helps express them in daily life.
This approach can accept secular laws as "sharia-compliant" if they reflect Islamic values. "Even simply by trying to respect Muslim ethics, one is already in the process of applying the sharia," Ramadan has written.
Thus Williams, who cited Ramadan in his speech, said Britain already had sharia in its legal system through laws that allowed Islamic no-interest mortgages and contracts.
Another leading thinker, French imam Tareq Oubrou, advocates a "sharia for minorities" respecting Islamic values as ethical guidelines for Muslims and civil jurisprudence as the law for all citizens in a country.
(For more on religion, see the religion blog FaithWorld blogs.reuters.com/faithworld)
(additional reporting by Reuters bureaus)