One of the big problems in this field is that there's so much mystification that surrounds talk of the Shari'a, whether its saying that Islam is all about peace or whether its people saying that Islam is all about Jihad and all about suicide bombs. People will make statements which don't seem to be backed up by any sort of historical context.

I was a teenager when General Zia took power in the Pakistan; I was in my twenties when I went there during the late 1980s and I saw then not only the novel punishments that he was introducing - because they were novel, and this is again something that's very important to understand, it's only in the last thirty, forty years, since 1979 in fact, that these penalties have been revived anywhere in the world apart from Saudi Arabia.

The one fatwa that everyone here is probably familiar with is the Salman Rushdie fatwa, but a fatwa doesn't have to be a violent thing at all. A fatwa is simply a ruling on Islamic law; there can be fatwas on clothing.

In 1979, you had the revolution in Iran. You had the Hudood Ordinances in Pakistan, which are the laws that are notoriously used against women, which are theoretically used against thieves although they're never carried out - an actual amputation or an actual stoning. The blasphemy laws, again, never actually carried out, though they're there, heavy with menace on the statute books.

People are coupling and decoupling all the time in Great Britain. The fact that Muslims choose to precede it with a certain formula of words, shouldn't bar them from anything. But, no one's saying that polygamy should be institutionalized in this country. That Muslim's uniquely should be allowed to have two or three or four marriages.

One of things that surprised me when I was in Iran was to find out that the country finances seven times as many sex change operations as the entire European Union. And the reason for that is because Ayatollah Khomeini himself, in the early 1960s, in the same time that he was developing this other idea of an Islamic state, also hit upon the idea that if a person is born into the wrong sex, it was entirely proper for them to change sex.

There's crucial distinction that has to be drawn between the Shari'a, which is this hugely expansive vision of cosmic order that I've been describing, and principles of Islamic law, known in Arabic as "Fiqh" - a word that means understanding. If you're a devout Muslim, you don't argue against the Shari'a; the Shari'a is the path that God has laid down. But what you can do, and what people are doing all the time, is arguing over the correct interpretation of the Shari'a, arguing over the Fiqh. That's something that has been going on throughout Islamic history.