On October 11, at the end of Islam's holy month of Ramadan, 138 Muslims from around the world addressed a letter to Pope Benedict XVI and numerous other Christian leaders. Entitled "A Common Word Between Us and You," the letter was released in a media-savvy rollout in several world capitals and was welcomed with enthusiasm by one of the addressees, Canterbury's Rowan Williams. Cardinal Jean-Louis Tauran, president of the reconstituted Pontifical Council for Interreligious Dialogue, was cordial but cautious, suggesting that while there were certainly things to talk about based on a shared commitment to the two Great Commandments of love of God and love of neighbor, there were also many difficulties.

Something else struck me about "A Common Word" and the media commentary on it: both the letter's signatories and the reporters writing about it seemed unaware of the proposal for framing a new dialogue between Christianity and Islam made by the Holy Father last December, in his Christmas address to the Roman Curia. There, Benedict XVI proposed that the dialogue focus on the question of how religious traditions assimilate the positive achievements of the Enlightenment. Those achievements include the victory of the idea of religious freedom as an inalienable human right -- a human right that, acknowledged in law and thus erected into a civil right, leads to distinctions between religious and political authority in a just state.

Catholicism, the Pope reminded the Curia, had spent the better part of two centuries trying to find solutions to the questions of faith, freedom, and governance posed by the Enlightenment, a process that bore fruit at the Second Vatican Council. Might there be something in this Catholic experience of retrieval-and-renewal for a Christian-Islamic dialogue to ponder?

These do seem to be the most urgent questions. For unless Islam can find within its own spiritual resources a way to legitimate religious freedom and the distinction between religious and political authority, the relationship between two billion Christians and a billion Muslims is going to remain fraught with tension. "A Common Word" speaks at length about the two Great Commandments; it says nothing about their applicability to issues of faith, freedom, and the governance of society: issues posed, for example, by the death threats visited upon Muslims who convert to Christianity and by the refusal to allow Christian public worship in Saudi Arabia. "A Common Word" also seems rather defensive, as if it were 21st century Christians who, in considerable numbers, were justifying the murder of innocents in advancing the cause of God. But that is manifestly not the case.

Knowledgeable analysts of Islamic affairs have also raised questions about the composition of the "138," which includes a considerable number of government functionaries as well as figures with connections to Wahhabism, the fanatic sect whose teachings and financial influence inflame so much Islamist agitation around the world. Be that as it may -- and it's not an insignificant thing -- I would suggest that the better approach would be to ask the people who put "A Common Word" together why the Pope's invitation of last December was not addressed.