Pope Benedict XVI has drawn a collective response from the Muslim world, in the form of an open letter from 38 Islamic leaders regarding his September 12 address in Regensburg. “All the eight schools of thought and jurisprudence in Islam are represented by the signatories,” according to a press release hailing the letter as “unique in the history of interfaith relations.”  The pope provoked outrage by suggesting that Islam rejects reason: the open letter proves him right. They argue that there is no dichotomy in Islam between reason and faith, which turns out to mean that there is no role for reason.
Some of the issues raised in the Muslim response are bit abstract, but the practical implications are quite stark. Theology, as Benedict stated on September 12, is “inquiry into the rationality of faith.” Its most important function is to reject purported revelation that cannot possibly be true, such that faith may acknowledge revelation that might be true. Christianity and Judaism have endured two centuries of withering criticism from scientific study of their sacred texts. To perform the same function in the case of the Koran puts a scholar’s life at risk. I do not know whether the scholars who question the Koran’s authenticity are correct – I am not a specialist in such matters – but I am quite sure that their conclusions are reasoned. If reason might demonstrate the founding premises of a religion to be false, it is nonsense to argue, as the clerics do, that reason itself can be subsumed into a system of religious belief.
Reason and faith need each other, the pope argued in Regensburg. At the same time, modern science requires philosophical, and even theological premises which it cannot itself provide. Kurt Goedel, the 20th century’s greatest mathematician, proved that no mathematical system can prove its own axioms, which must be accepted as if it were a matter of faith. As Benedict said: “Modern scientific reason quite simply has to accept the rational structure of matter and the correspondence between our spirit and the prevailing rational structures of nature as a given, on which its methodology has to be based. Yet the question why this has to be so is a real question, and one which has to be remanded by the natural sciences to other modes and planes of thought – to philosophy and theology.”
But the pope added, “For Muslim teaching, God is absolutely transcendent. His will is not bound up with any of our categories, even that of rationality … God is not bound even by his own word, and that nothing would oblige him to reveal the truth to us. Were it God’s will, we would even have to practice idolatry.” Conversion by force through jihad is the consequence of irrationality.
Here is the response of the 38 Muslim clerics in the open letter:
[T]he dichotomy between “reason” on one hand and “faith” on the other does not exist in precisely the same form in Islamic thought. Rather, Muslims have come to terms with the power and limits of human intelligence in their own way [emphasis added], acknowledging a hierarchy of knowledge of which reason is a crucial part … [I]n their most mature and mainstream forms the intellectual explorations of Muslims through the ages have maintained a consonance between the truths of the Koranic revelation and the demands of human intelligence, without sacrificing one for the other. God says, We shall show them Our signs in the horizons and in themselves until it is clear to them that it is the truth (Fussilat 41:53). Reason itself is one of the many signs within us, which God invites us to contemplate, and to contemplate with, as a way of knowing the truth.
Reason, the Muslim clerics aver, is one more of the “signs in the horizon” that God sets before us to reveal His presence, like sunsets and rainbows. Now, I suppose that sunsets, rainbows, cellular mitosis and one’s capacity to bisect an angle all might serve as inspiration. Reason in the West, though, is something quite different. Reason first of all is the capacity to doubt, to subject belief to the sort of merciless questioning that made Socrates so unpopular in Athens. Benedict drew a parallel between Socratic reasoning and Hebrew revelation to which I objected (Not what it was, but what it does, October 3, 2006). Socratic reasoning is ironic and destructive in Kierkegaard’s reading, not affirmative of faith.  But that is a secondary matter here.
Reason, in the Muslim clerics’ view, is a sign from God, an object that God has created and planted in our brains to show us God’s presence. For example, if I say that as a reasoning fellow I don’t believe in Allah, the answer must be, “Aha! You are using your reason to doubt the existence of Allah, and the fact that you have reason demonstrates the existence of Allah, because if you have reason, someone must have given it to you, and that only could be Allah.”
To state that the dichotomy between faith and reason simply doesn’t exist in Islam is another way of saying that Islam does not admit reason. The modern concept of reason, Benedict observed in his September 12 address, begins with Rene Descartes in the 17th century, who shifts the subject to the individual man away from God.
Descartes’ most famous dictum, “I think, therefore I am,” changes the subject from the Scholastic question, that is, the existence of God. Rather than ask, “How do I know whether God exists?”, Descartes asks, “How do I know that I exist?” To which the simple answer is: if I don’t exist, then who’s asking the question? Following our 38 Muslim clerics, the Muslim reply must be: “Aha – you believe that you have thoughts, but those thoughts must come from somewhere, and where could those thoughts come from, except for Allah? It is not ‘I think, therefore I am’, but rather, ‘I think, therefore Allah is.'”
If God simply has planted reason in our brain the better to demonstrate to us His presence, then we have no thoughts that God does not send us. God as it were has placed a radio transmitter in our brain and is sending us signals.
The trouble is that not only Allah can plant a radio transmitter in our brain, but also Satan. Suppose I employ reason to conduct the most elementary sort of consistency check on the Koran. I will have trouble reconciling Sura 47:4 (“When you meet the unbelievers, strike off their heads,” etc) with 50:45 (“We well know what the infidels say, but you are not to compel them”), and hundreds of other verses on other subjects. Reason shows only a contradiction; reconciliation of such statements requires recourse to a tradition of “abrogation” of supposedly early verses by later verses for which no empirical demonstration exists.
Men of reason have argued for centuries that Judeo-Christian revelation must be a hoax, on the strength of such observations as:
1) The repetition of numerous stories in the Bible (for example, the two Creation stories in Genesis 1:27 and Genesis 2:7) suggests multiple authorship and the redaction of conflicting stories;
2) Unmistakable differences in style within books attributed to a single author (for example, the two or three Isaiahs);
3) Evident corruption of certain texts; 
4) Glaring differences among the four Christian Gospels (eg, two different lineages for the Virgin Mary), not to mention the existence of variant Gospels; 
5) Suspicious similarities between the Christian Eucharist and the pagan cult of Dionysus
And so forth. Christians and Jews have had to come to terms with these and countless other quite reasonable objections, with the understanding that reason is a different function than faith.
Muslims have yet to come to terms with similar objections, including such scholarly arguments as the following:
1) There are numerous variant versions of the Koran, making it quite unlikely that the Archangel Gabriel dictated the entire document to the Prophet Mohammed;
2) Approximately a fifth of the Koranic text is “just incomprehensible” according to Professor Gerd R Puin of the University of Saarbruecken;
3) Much of what is incomprehensible in Arabic makes good sense if one reads the text instead in Syriac, the liturgical language of pre-existing Christian communities in the Middle East, according to “Christoph Luxenburg”;
4) The archeological evidence (assembled by Yehuda Nevo) from the Koranic period strongly contradicts the notion that a finished text of any sort existed within a century of Mohammed’s death.
The scholarly arguments that the Koran had nothing to do with the Archangel Gabriel, but rather consists of a much later hodge-podge of poorly edited and contradictory material, much of it cribbed from easily-identified Jewish and Christian sources, are vast, and easily available.  They are matters for specialists, and I do not need to adopt a stance toward them. It is quite clear, though, that if the Koran is a 9th-century redaction rather than a 7th-century revelation, of course, Islam has a serious problem.
If the Pentateuch of the Old Testament was revealed to a handful of individuals, not just to Moses as tradition has it, Christians and Jews can absorb the damage. Not so Muslims if the Koran was revealed to (or redacted by) someone else than Mohammed. That is why some prominent text critics of the Koran publish under pseudonyms (“Christoph Luxenburg,” “Ibn Warraq”), or not at all.
In the Western tradition, Descartes’ man – rather than God-centered metaphysics – led first to a revolt against faith. But science, as Benedict argued on September 12, had to learn its own limitations. Creation ex nihilo, once derided as the most unreasonable of Biblical doctrines, does not seem so unreasonable now that the physicists concede that all the laws of nature cease to have meaning prior to the origin of the universe in the Big Bang. Mathematics, thanks to Kurt Goedel, now must admit its axioms depend on faith rather than proof. Modern reason began as the antagonist of faith, but in its best manifestation has been housebroken into its proper role as the Accusing Angel in the heavenly court.
The core of the issue is human freedom. Reason is a gift from God, to be sure, but it is a parent’s gift of love to a child: the capacity to doubt and even to rebel, in the hope that grace will overcome man’s obstinacy. The 38 clerics, by contrast, consider reason no more than another feature of nature to be contemplated on the horizon. That is what Benedict means when he characterizes Allah as “absolutely transcendental.” As Franz Rosenzweig explained, mainstream Muslim theology
… presumes that Allah creates every isolated thing at every moment. Providence thus is shattered into infinitely many individual acts of creation, with no connection to each other, each of which has the importance of the entire creation. That has been the doctrine of the ruling orthodox philosophy in Islam. Every individual thing is created from scratch at every moment. Islam cannot be salvaged from this frightful providence of Allah … despite its vehement, haughty insistence upon the idea of the God’s unity, Islam slips back into a kind of monistic paganism, if you will permit the expression. God competes with God at every moment, as if it were the colorfully contending heavenful of gods of polytheism. 
Doubt, that is, reason, will not find a place in Islam, if the 38 clerics are a fair representation of Muslim thinking.
 Click here for the press release. Scroll down to find a link to the full text of the letter.
 Socrates the destroyer, May 25, 2004.
 See the entry on the “Book of Job” in the Encyclopedia Judaica, for example.
 See for example Elaine Pagels, The Gnostic Gospels (Random House, New York, 2004).
 See Ibn Warraq, What the Koran Really Says (Prometheus Books: Amherst NY, 2002). Warraq, an apostate from Islam, republishes the most important scholarly arguments for the inauthenticity of the Koran.
 Oil on the flames of civilizational war, December 2, 2003.