John Paul II's papal rule was largely defined by his relationship with a global conflict between West and East. On Tuesday 12 September 2006, in a badly judged speech before a home crowd of Bavarian academics, Benedict XVI may well have set the parameters of his own period as Pope, pitching himself into a debate over Islam that has prompted outrage throughout the Muslim world.
"Show me just what Muhammad brought that was new and there you will find things only evil and inhuman, such as his command to spread by the sword the faith he preached." These were not the Pope's words, but those of an obscure Byzantine emperor, Manuel II Paleologos, back in the 14th century.
And yes, the Pope did make it clear he was offering a quotation. Even so, these words fell from the lips of the spiritual leader of a billion Christians without anything like enough qualification. There was no phrase distancing himself from the claim that Muhammad was responsible for evil. It's little surprise, therefore, that the remarks have roused anger and demands for a personal apology.
Christopher Tyerman's latest book on the Crusades, God's War, argues persuasively that analogies between the Crusades and the present global conflict are often overdrawn and historically dubious. That may be so. But it's an argument that doesn't cut much ice with millions of Muslims. After all, it was one of Benedict's predecessors, Urban II, who first summoned a Christian jihad against Islam. And it's born-again Christians who have been at the forefront of support for the invasion of Iraq, the occupation of Palestinian lands by Israel, and the whole "reorganisation" of the Middle East - a catastrophe in which many thousands of Muslims have lost their lives.
Any comments by a Christian leader that touch upon this wound are bound to be interpreted from every possible angle. The Pope must have known this. If millions of Muslims were offended by the scribblings of a few unknown Danish cartoonists, it's pretty obvious the enormous potential for harm that might flow from a few ill-timed comments by the vicar of Rome.
Furthermore, the Pope has form on all of this. Just a few months before he was elected, he spoke out against Muslim Turkey joining the European Union. Christian Europe must be defended, he argued. It didn't go down well at the time with Muslim leaders.
But what makes his comments from Bavaria doubly insensitive is that Munich and its surrounding towns are home to thousands of Gastarbeiter, many from Turkey, who are often badly treated by local Germans and frequently subjected to racism. It won't be lost on them that Manuel II ran his Christian empire from what is now the Turkish city of Istanbul. And reference to that time, in circumstances such as these, has the unmistakable whiff of Christian triumphalism.
For the most part, the Pope's address was a scholarly exercise that sought to challenge the idea that rationality is intrinsically and necessarily secular. We must "overcome the self-imposed limitation of reason to the empirically verifiable", he insisted. Most Christians would agree. But even here there was a sharp criticism of Islam buried beneath the scholarly rhetoric.
For the Pope argued that in Muslim teaching, because "God is absolutely transcendent", He is "not bound up with any of our categories, even that of rationality". In other words, there is no reasoning in or with Islam. Which, surely, is another way of the Pope saying how dangerous he thinks Islam is.
This is why the Pope's remarks look rather more than just a slip or a casual mistake. The speech concludes with a further reference to the views of the Byzantine emperor: " 'Not to act reasonably, not to act with logos, is contrary to the nature of God,' said Manuel II, according to his Christian understanding of God, in response to his Persian interlocutor. It is to this great logos, to this breadth of reason, that we invite our partners in the dialogue of cultures."
Weblogs have been buzzing with the thought that the Pope may have the president of Iran in mind when he speaks of Manuel's Persian interlocutor. But we don't need to speculate upon a contemporary casting for this speech to recognise its dangers. For in claiming that Islam may be beyond reason, and then to claim that to act without reason is to act contrary to the will of God, is pretty close to the assertion that this religion is godless. And that's not how different faiths ought to speak to each other - especially when we all have each other's blood on our hands.
As it is written in the Gospels: "Why do you look at the speck of sawdust in your brother's eye and pay no attention to the plank in your own eye? How can you say to your brother, 'Let me take the speck out of your eye,' when all the time there is a plank in your own eye?"