Too many people --- politicians and ordinary citizens alike --- continue to refer to the "war on terror" as if terrorism were the enemy. As a number of more careful commentators have pointed out, terrorism is simply the deadly means employed by the enemy; it is not itself the enemy.

The real and immediate enemy is Islamic fundamentalism. Not Islam as such, but Islamic fundamentalism. To be sure, the all-encompassing problem is fundamentalism of every kind, in whatever religious tradition it is found.

Religious fundamentalism flourishes, for example, within Shi'ite and Wahabist Islam, within ultra-orthodox and orthodox Judaism (the Haredim and Hasidim), within so-called Bible-belt Protestantism, and increasingly, in recent decades, within Roman Catholic traditionalist circles as well.

Of course, fundamentalism is a complex phenomenon, having been the subject of serious and sustained study by Martin Marty, emeritus professor of church history at the University of Chicago, and his former student and current Notre Dame professor, R. Scott Appleby, who co-edited a highly regarded five-volume series on the topic.

Given the general focus and audience of this column, however, its attention will be directed mainly to Catholic fundamentalism, with the hope that its broader ecumenical and inter-faith implications will be evident.

One of the best articles ever written on the subject of Catholic fundamentalism appeared over 17 years ago in the Jesuit weekly, America (April 11, 1987). It was entitled, "The Rise of Catholic Fundamentalism." Its author, Jesuit Father Patrick M. Arnold, has since died.

So impressive was his piece that I devoted an entire column to it. I think it worthwhile now, if only as a memorial to Father Arnold, to reproduce the main points of his article. It stands up very well indeed to the passage of years.

Like all careful and insightful observers of the fundamentalist scene, Father Arnold took care to distinguish between fundamentalism and conservatism, with which it is often confused, to the detriment of conservatism.

Conservatism, he insisted, fulfills a necessary and constructive role in the church and in society alike. It is concerned with preserving a community's historical heritage, especially in times of cultural change. It urges a cautious approach, as captured, for example, in the familiar saying: "Look before you leap."

Fundamentalism, on the other hand, is neither necessary nor constructive. Working out of an absolutist perspective, it sees the world as filled with evil forces conspiring against everything that it regards --- with unquestioned certitude --- as true and good.

Father Arnold identified five unhealthy characteristics of religious fundamentalism in general and of Catholic fundamentalism in particular.

First, it is marked by paranoia and self-righteousness. There is always some terrible enemy out there that has to be fought and ultimately destroyed.

Fundamentalism is marked, secondly, by fear and rage directed not only against the enemy outside the ranks but even more intensely against the enemy within, including bishops, priests, sisters and theologians.

Father Arnold called this "the most revealing and dangerous characteristic" of fundamentalists because it leads them to engage in divisive activities. They spend an inordinate amount of time and energy trying to purge people, to get them fired, to destroy their reputations and, therefore, their influence.

Fundamentalists are captivated, thirdly, by the "myth of the Golden Age." They imagine that Catholicism in the decades just before Vatican II was in its pristine and ideal state, exactly as God intended it to be, without problems or deficiencies of any kind.

For the fundamentalist, fourthly, all truth is to be found in a single source. For the Muslim, it is the Koran. For the Jew, the Torah. For Protestants, the Bible. And for Catholics, the pronouncements of the pope and the Roman Curia.

Fifthly, religious fundamentalists tend to link themselves with right-wing political regimes and movements in the hope of advancing their own theocratic policies. Accordingly, Catholic fundamentalists are unenthusiastic about Catholic social teaching. They tend instead to emphasize a limited range of other issues as if they were primary.

Less than two years later, another Jesuit scholar, Father John Coleman, addressed the same topic in Commonweal magazine, linking today's Catholic fundamentalists with the Integralist movement of the early-20th century. The Integralists also claimed that the most dangerous enemies of the church are within, and that the way to deal with them is through censorship, repression and even excommunication.

Father Coleman offered some examples: Comunione e Liberazione in Italy, Opus Dei in Spain and around the world, and Catholics United for the Faith and the Wanderer Forum in the United States.

Not since the pontificate of Pius X (1903-14), when the Integralists flourished, have groups of this type enjoyed such favor at the highest levels of the Vatican.

Father Richard P. McBrien is the Crowley-O'Brien Professor of Theology at the University of Notre Dame.