A FAILING CIVILIZATION CAN'T BE argued out of its failing. It can be led, perhaps, or inspired, or converted and reformed. But argument requires the application of universal truths to the particular facts of the moment, and when a culture is tumbling downward, all its truths and facts--indeed, the whole idea of truth and fact and argument--are exactly what its people increasingly disbelieve.

Does anyone doubt that Western Europe is tumbling downward? It cannot summon the will to reproduce itself. It has aborted and contracepted its birthrate down toward demographic disaster: perhaps 1.4 children per couple across the western end of the continent, when simple replacement requires a rate around 2.1. It can discover neither how to absorb nor how to halt the waves of Islamic immigrants swamping its cities, and it has proved supine in the face of those immigrants' anti-Semitism, anti-Christianism, and even anti-Europeanism.

Meanwhile, Western Europe's economies are soft, its unemployment rates are shocking, and its emerging continent-wide government is elitist and antidemocratic. Its people are hedonists and materialists, its soccer clubs are nativist militias in waiting, its churches are empty, and--well, that's the problem Joseph Ratzinger faces, isn't it? The newly elected Pope Benedict XVI has just inherited the world's greatest pulpit, but, on his home continent at least, there's hardly anyone in the pews to listen.

He can preach to the choir, of course: After nearly three centuries of enlightened disdain for religion, Europe is about as dechristianized as it's likely to get; everyone who's going to leave the Church already has, and still there are millions of believers scattered across the continent--to say nothing of the billion or so who don't happen to live a train ride away from Rome. In all likelihood, the European Union and the national governments will soon cave in and grant their Muslim immigrants the religious exemptions those governments have consistently refused to grant Catholics. And that will prove what the Vatican claimed all the way back in its struggles with the French Revolution: The European form of Enlightenment secularism and laïcité was never some purely philosophical stand on the necessary political separation of church and state; it always began and ended with anti-Catholicism.

It still does. As the refusal to mention Christianity in the historical preface to the new constitution of the European Union proves, Catholics in Western Europe are going to have to look out for themselves. They're only a remnant, but they're still a large one, and to them Benedict XVI can continue carrying the message of the Church--even though they live on a continent where the Italian conservative Rocco Buttiglione was not allowed to become a European commissioner because, it was argued, his Catholicism was incompatible with the office, and where influential French figures protested loudly when France's president dared to attend John Paul II's funeral.

And yet, the moral and intellectual force of the papacy derives from the fact that no one ever thought of Catholicism as merely preaching to the choir. People are fascinated by it, French secularists are anti-it, every newspaper in the world carried headline after headline these last three weeks about it--all precisely because, for good or for ill, the Catholic Church has never admitted that it is a sect. It always insists that it is a universal church--catholic, as Catholics like to say--and it claims to speak with a force that doesn't come just from the political power of its believers. It is a way of thinking and being: a reasoned moral argument about how human life might best be lived.