The ex-Muslim Sultan is undoubtedly a powerful voice in her native Arabic, and even in English she is impassioned and speaks with a memorable turn of phrase. In contrast, Pipes is measured and softly spoken, carefully and persistently making his case. I commend the debate to readers, not because one party won the day, but because the speakers were addressing important questions, which will exercise many minds for years-perhaps generations-to come. My concern here, however, is to focus on an important comparison between medieval Christianity and present-day Islam, which was raised by someone in the audience who asked: "I will suggest that this [radical Islam] is not that different from Christianity at the time of the Crusades, which was a very belligerent religion compared to what it is today. So look at that in terms of the evolution of a religious doctrine, and how long does that take?"

On countless occasions over the years I have heard this comparison: Christianity has undergone its reformation, so why not Islam? The European Reformation took centuries-why wouldn't an Islamic reformation also take time? Isn't it all a matter of time?

This line of thinking arises from a worldview that looks at ideologies through the lens of "progress" or "evolution," shaped by a kind of Darwinism. The underlying presupposition is that human societies evolve as time passes, progressing and becoming more humane and more advanced.

Time has become a yardstick to measure the ever-improving character of human social order. It is the embedding of the idea of progress into our everyday language which gives credibility to the question. "Can Islam not undergo its own reformation, too?"

There is another problem with comparing today's Islam with pre-Reformation Christianity, and this has to do with the meaning of "reformation" itself. It has become accepted by many thinking people today that "reformation" means some kind of softening, a "moderating" process, a manifestation of "progress." This far from the truth.

Throughout the whole medieval period the idea of reformation (reformatio) was prestigious, and many reform movements chased after this ideal. Reformation meant going back to one's roots. For medieval Christians, a reformed Christianity meant being more Christ-like, more apostolic, and more Pauline. The wealthy St. Francis read Jesus' words about giving away one's possessions to feed the poor, so he followed this teaching, and many flocked to join him. Thus the Franciscans were founded as a reform movement.

St. Francis was a radical reformer. He was not inspired by a vision of making Christianity more moderate and progressive. What moved him was a desire to follow the Jesus of the Gospels.

Likewise, Martin Luther recalled the words of Paul about freedom in the letter to the Galatians-"for freedom Christ has set us free"-to exhort the German nobles to claim their own freedom from ecclesiastical authority.

The European Reformation-so often invoked in comparisons with Islam today-was driven by a desire to reform Christianity a second time, taking it back to its roots. It sought to move ahead by going backwards. The Reformation was not a "progressive" movement in the modern sense, but one which sought to "regress," renewing the example of Christ and His apostles.

This is why Luther and other reformers encouraged believers to read their Bibles for themselves, in their own native tongue. Luther regarded it as the duty of every Christian to be constantly renewing his faith from the original sources. Like St. Francis, Luther was a Christian radical.

It is true that some changes brought in by the European Reformation had a moderating effect on Western intellectual life. There developed a greater emphasis on freedom and individual responsibility, for example. The Protestant work ethic was one byproduct of this emphasis. Yet these developments did not take place out of a desire to develop a more moderate form of Christianity, but because they were regarded as conforming more to the Bible.

Therefore, according to the core meaning of "reformation"-a return to one's roots-reforming Islam would mean making it more Muhammadan. An Islamic reformation would produce a religion which is closer to the Quran, and above all, closer to the example and teaching of its founder.

The hankering of some Westerners after an Islamic reformation begs the question: What would it mean to follow Muhammad's example more closely?

As it happens, such a movement has been underway for more than 100 years and is in full swing today. It is what we know as Islamic radicalism. The ideal of an Islamic reformation has produced, among many other results, the global jihad movement, the push for Shariah revival and reimplementation of the Caliphate. This is what a desire to revive the example and teaching of Muhammad has led to.

There are two main reasons why renewing the example of Muhammad leads to Islamic radicalism.

One is that Muhammad combined within himself the offices of king, judge, general, and religious leader, thus unifying politics, law, the military, and religion. To follow his example means creating a theocratic political order, where the laws of the land are controlled by Islamic theology.

In contrast, Christian tradition has always distinguished the secular from the ecclesiastical, based on the Hebrew distinction between priests and kings. This feature of medieval Christianity-separation between religion and politics-was severely criticized by famous Muslim scholar Ibn Khaldun. Muslim thinkers had always regarded it as one of the key weaknesses of Christianity.

The second reason why renewing Islam leads to radicalism is that many of the harsher elements of Islamic law-such as death for apostates, stoning adulterers, cutting off the hands of thieves, enslaving one's enemies, and killing nonbelievers-are firmly grounded in Muhammad's example.

Australian Muslim Waleed Aly was entirely correct when he said Islam has already had its reformation, and the outcome has been Islamic radicalism:

"Still, Western calls for an Islamic Reformation grow predictably and irrepressibly stronger, while those familiar with the Islamic tradition easily observe that radical and terrorist groups such as al-Qaeda and the Taliban, cannot be cured by Reformation for the very simple fact that they are the Reformation." In today's world, if what is needed is a more moderate manifestation of Islam, then the very last thing that could ever accomplish this would be an Islamic reformation.

----Mark Durie is an Anglican priest, human-rights activist, and scholar in Australia