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.

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.

My background is such that I am uneasy about religious laws, I think there's always a real danger when you start appealing to a higher authority. It's self-righteousness, it's not righteousness, it's self-righteousness that takes control. But I think that it's absolutely crucial that that's not confused with the debate that takes place over Shari'a law in Great Britain at the moment. Because as far as anybody is concerned, when you talk about Shari'a courts now you're talking about - I don't know what people think.

I think it's important to understand Shari'a to be rooted in history - what we know about the history and what we don't know about the history. So then, if people want to argue, at least they're arguing from the same point and we know what we know, and we know what we don't know.

There have been lots and lots of fatwas against violence. But it is an interesting question. A Mufti is the person that issues the fatwa and you'll find Muftis at all the Madrasas. Basically once you've studied for long enough you have the authority to issue a fatwa. But there are limits. I can bang on and on on the point but all I'm really saying is that there isn't a simple answer.

I realized that the ignorance was profound. I don't mean that in a pejorative sense, it's just that people didn't know what the Shari'a was, as such. They knew that it was something good. I should say perhaps that the Shari'a, etymologically in Arabic, means a desert path to water. It means a path towards salvation, in the seventh-century context, to the desert people. If you have a path to water, that's the path you want to take to get you where you want to get to; where you should get to. And that much was clear but beyond that people didn't know what the rules were.

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.