If there is any consensus among spokesmen and students of religion commenting on the events of Sept. 11, it is that those behind them do not in any way represent the Islamic faith. As the distinguished scholar of fundamentalisms, Martin E. Marty, put it in last week's New York Times Magazine, "this is not Islam." The desire to exculpate Islam is understandable, not only on grounds of toleration and good sense, but also given the very real dangers some of our Muslim citizens have faced in recent weeks. Yet a larger question looms: to what degree does any religion bear responsibility for those who speak in its name?

Here the specialists are clearly of two minds. Over the past decade there has been a growing movement to hold secular and religious institutions responsible for past harms they caused, either by apologizing or by providing restitution. The results have been mixed, and in some cases questionable. But certainly one good result is that the Roman Catholic church has been forced to confront its past in relation to European Jewry. The deep issue this confrontation has raised is not whether individual church authorities abused their powers or distorted church teaching, but whether there is something in traditional church doctrine — said or unsaid — that made official anti-Semitism possible for centuries.

It is all very well for Catholics today to insist that their faith, properly interpreted, does not condone anti-Semitism. But that does not get us closer to understanding how millions of Catholics over a millennium could have thought that it did. Any Catholic who is serious about his faith must pose this question to himself.

The Vatican can and should be held responsible for the history of the Roman Catholic Church because it has the sole right to determine doctrines of faith. Muslims, like Jews, recognize no central doctrinal authority, rendering it more difficult, even for believers, to distinguish orthodoxy from heterodoxy and heresy. Yet if any religion is to cope with these deviations it must recognize that they do not arise from nowhere but have roots, however twisted, in the faith itself. Christians who bomb abortion clinics appeal to the Christian Bible and persuade others to join them on Biblical grounds. That Islamic fundamentalism and its militant offshoots appeal to the Koran is therefore not an incidental matter. It means that they have found a way to breed in the religious space opened up by the revelation Islam presupposes.

Muslims the world over bristled when President Bush spoke of the campaign against terrorism as a "crusade," a word they still associate with the slaughters of medieval Christian incursions. And they are not wrong to do so: there is a plausible "crusading" interpretation of Christianity that appears periodically in Christian history, and which the Christian churches need to protect themselves against. The same temptation exists in Judaism today, as one sees in the more radical branches of the Israeli settlers movement, which is fired by the eschatological belief that reclaiming the land will hasten the coming of the Messiah. All the great monotheistic faiths have had, and continue to have, trouble reconciling their understanding of revelation with the reasonable demands of political life — yet reconcile it they must.

This is why those concerned with Islam's place in the world today are obliged to study seriously the theological sources of Islamic fundamentalism and the apparent absence of theological defenses against the spread of political extremism. Recent public discussions of Islam have been informed by a humane spirit of toleration, but they mark an abdication of intellectual responsibility among Muslims and non-Muslims alike. Reflection on this matter must begin with the uncomfortable fact that in religion, as in nature, there is no such thing as spontaneous generation.