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.

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.

If Muslims want to take their disputes to religious arbitrators because they genuinely believe that it's a matter of great spiritual importance that they do that, they shouldn't be the only community in this country that's denied the opportunity to do that. Because the Jewish population has been entitled to take their disputes to tribunals known as the Beth Din for over one hundred years, and the Church of England is integrated into the fabric of this country, and there are ecclesiastical tribunals where religious disputes can be dealt with.

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.

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.

Whenever one writes a book one should have a notional reader in mind.

My father's from Pakistan and he has been a secularist all his life. In the Pakistani context, there's no messing with religion. There's been a battle for the soul of Pakistan since 1947 and I have grown up without any illusions about the dangers of religious power in the context of a country like Pakistan.