This is the crux of the issue. As Robert Reilly points out in his recent essay on the subject, there were voluntarist tensions in both Christianity and Islam. The pope himself criticized medieval Catholic theologian Duns Scotus for promoting voluntarism. But the temptation was a little stronger in Islam, owing it the nature of its revelation. Specifically, its belief that the word of God is encapsulated in a text, dictated to the prophet, lends itself naturally to voluntarism. Catholicism's approach to revelation is fundamentally different, seeing the Word of God as not a book, but a person (Jesus) who is also the wisdom and reason of God. In this context, the role of the Church is to preserve the memory of Christ, not appeal to a timeless text. But it is not so black and white. Catholics such as Duns Scotus flirted with voluntarism, while there was once a flourishing rationalist school in Islam that dominated its golden age. As Reilly notes, the Mu'tazilites believed God is reason and that God's laws are laws of nature, manifested in Sharia. And during this period, there was much mutually beneficial cross-fertilization between the Christian and Islamic civilizations. The most well known example is the debt Thomas Aquinas owes to prominent Muslim intellectuals such as Averroes and Avicenna.
But the Mu'tazilites lost prominence in the development of Islam. Reilly argues that the most influential Islamic thinker after Mohammed was Hamid al-Ghazali (1058-1111), who utterly rejected Greek philosophy. Al-Ghazali was a voluntarist, arguing that God is not bound by what we perceive as the rational order, and that "things do not act according to their own natures but only according to God's will at the moment." Reilly quotes a Jewish follower of al-Ghazali, Judah ha-Levi, noting that "I consider him to have attained the highest degree of perfection who is convinced of religious truths without having scrutinized them and reasoned over them." Taking this argument to the frightening extreme, Reilly concludes:
"Today's radical Muslims embrace the "unreasonableness" of faith in an unreasoning God and translate it into a politics of unlimited power. As God's instruments, they are channels for his omnipotence. Once the primacy of force is posited, terrorism becomes the next logical step to power, as it did in the 20th-century secular ideologies of power, Nazism and Marxism-Leninism. This is what led Osama bin Laden to embrace the astonishing statement of his spiritual godfather, Abdullah Azzam, which Osama quoted in the November 2001 video, released after 9/11: "Terrorism is an obligation in Allah's religion." This can only be true - that violence in spreading faith is an obligation - if, as Benedict XVI said in Regensburg, God is without reason."Did the Islamic civilization suffer because a bankrupt voluntarism became the predominant philosophy and theology? And does this explain the sway that religious compulsion and violence holds over an significant minority of Muslims today, the very ones that were baying for the pope's blood after his speech? These are subtle concepts, easily misunderstood. This is brought out clearly in a recent New Republic essay by David Nirenberg, who criticizes the pope for saying that Catholicism is better than all other religions:
"The pope's "invitation" at Regensburg was not to a "dialogue of cultures" at all. What he was advocating was a kind of conversion, or at least a convergenceThis completely misses the point. There is indeed a strong rationalist tradition in Islam, just as in Catholicism, despite very different views on the nature of revelation. It just has not come to the fore in a very long time. But it can be done. Christianity needed to wrestle with difficult texts in the bible, much as Muslims wrestle with the Qu'ran. For Catholics, the support provided in the Old Testament for the practice herem, the curse of destruction (basically genocide) is probably the most troublesome. Today, few Christians believe that God supports genocide, as this would contradict the logic of who God is. Muslims face similar challenges. A recent article in the New Yorker by George Packer gives some clues about how the Islamic community might deal with these issues, focusing on the teachings of Sudanese thinker Mahmoud Muhammad Taha. Taha distinguished between the harsh Medina verses and the more lofty Meccan verses in the Qu'ran, arguing that the former are only temporary, and will be abrogated in favor of the latter when Islam was ready. For his efforts, Taha was executed by the Sudanese authorities.
of all religions and cultures toward a logos that is explicitly characterized as
Catholic and European."
In sum, despite Nirenberg's best efforts to show otherwise, the pope is most definitely not calling for Muslims to convert to Catholicism. He is merely appealing to the Islamic community to recover what is best about itself. What exactly is wrong with that?