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.

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.

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.

I didn't quite know whether I was writing for the non-Muslim or the Muslim, and at the end of the day I'm writing, I hope, for people who are interested, whatever their faith. Even if they don't have any faith. As a barrister I had certain advantages - I could think like a lawyer and I knew how all the laws were fitted together and all the rest of it. One of the things I realized pretty early on while I was writing book about Shari'a was that that was as much a hinderance as it was a help because the Shari'a isn't just a system of rules.

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.

Ayatollah Khomeini issued a fatwa to that effect, which was then given effect in the Islamic Republic of Iran, so in the Islamic Republic of Iran, it's flexible enough to allow for sex changes, and it encourages sex changes. But if you want to change your religion in Iran, you've got some serious problems. There are other problems. You're allowed to change sex, but if you want to be a homosexual, theoretically at least, you face the death penalty. Quite how often these penalties are carried out is a moot point, but it's there on the statute books.

The Shari'a itself - this is possibly a kind of verbal debate - is understood to be something different from the Fiqh, and the Fiqh is the man-made element and the Shari'a is theoretically the divine element but it depends on one's personal beliefs.