Speaking of Remi Brague, this interview was published along with the release of his very excellent The Legend of the Middle Ages. You should read the whole thing, but this one question and answer provides a key sample for the larger project:
Question: How do you imagine a harmonious coexistence among the three religions of the book, and is such a coexistence even possible, given that Christianity has never stopped presenting itself as the verus Israel, and that Islam, as a religion, presented Muhammad as the key to the prophets? Should the latter notion be modified in the light of the works of Christoph Luxenberg, who claims that the Qur’an was not intended to replace the Bible, but rather to furnish a version of it intelligible to Arabs of the time?
Brague: Let me begin by rectifying a small lapse or two, which seem interesting to me. First, the formula that states that the Church is verus Israel (“the true race of Israel”) does not appear in the New Testament, but only in the Fathers of the Church, beginning with Justin.
Judaism, Christianity, Islam
And after then, if the idea is accepted, how was it understood? Did it mean that the Church was to be the true Israel, which supposes that the Jewish people would no longer be so? Or did it mean that the Church is one true Israel, truly Israel, and that it is truly attached to the experience of the God of Israel, because it sees itself, so to speak, as the resuscitated body of a Jew?
Next, the Qur’an does not speak of Muhammad as the key to the prophets, but rather as their seal (33:40). In context, the meaning of that expression is not totally clear, but it was interpreted as signifying that the message of Muhammad sealed the preceding messages, both because it confirms their content and because it brings prophecy to a close. If there is a key, it does not open anything (even in the sense of a hermeneutic key—such as a “key to dreams”); it closes. Behind this thought there is a claim to return to the series of the prophetic revelations of the past and to end it—a claim that Manes (or Mani, from whom we get the term “Manichaeism”) had perhaps already made in the early third century.
Christoph Luxenberg is just beginning to publish works to which I have tried to call the attention of a non-German-speaking public. For the time being, they remain dryly philological. He attempts to show that certain obscure passages of the Qur’an can be explained by the Syriac and involve Christian hymns. According to him, the Qur’an is, at least in part, what its title means in Syriac—a “lectionary,” or collection of biblical texts translated and adapted for liturgical use. I am not a specialist in this field, but this hypothesis seems extremely plausible, and its fertility speaks for it: many a mysterious passage becomes transparent. But we will have to wait for the true connoisseurs to give their opinions.
As for the problem of the basis for coexistence, you have put your finger on a fundamental difficulty. It contains a paradox: what is troublesome is not that any one religion finds another strange, but rather a certain manner of interpreting a real proximity. What exasperates Jews is that Christians claim to understand “their” book better than they do themselves. In similar fashion, what perplexes Christians—and why they often refuse to recognize Islam—is that Islam sees itself as a post-Christianity destined to replace that religion.
Recognizing or Refusing Filiation
For Islam, the survival of the Christian religion is an anachronism. Islam presents itself even as the true Christianity, given that, according to Islamic thought, Christians have disfigured the authentic Gospel, just as the Jews, for their part, have sold out the authentic Torah. Thus it is out of the question to appeal to common Scripture. This means that, from the Muslim point of view, the “Islamo-Christian dialogue” is a dialogue between true Christians (that is, the Muslims themselves) and people who imagine themselves to be true Christians but are not. This is why dialogue interests Christians more than it does Muslims.