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.

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.

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.

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.

There were periods in Islamic history when things like apostasy and blasphemy were made punishable. So you know it kind of depends - there's no argument, quite apart from the question of the divine or otherwise nature of the Qur'an, that huge swathes of Islamic law are man-made. Clerics here - in maintaining their power, will often try to elide that and say "Well no, actually this isn't man-made at all. Stoning is part of the divine revelation." It isn't in the Qur'an but the way this has been done over the years is to take the Hadith.

Whereas a man is entitled to marry three more times and that fosters great abuse, even scholars accept that. So certainly since the 1980s Shari'a courts have been established and they allow for women to go to them and they basically grant them annulment. It's not a civil divorce, they don't have the right to grant alimony or maintenance or custody.

I work in the human rights field and there are serious conflicts between certain interpretations of Islamic law and human rights. That's something which I don't make any bones about at all, it's something which I think is very important for everyone to address, including the Muslim community, and many Muslims are addressing that issue.