WHEN PRESIDENT BUSH used the term ''crusade'' last week, his spokespeople quickly disavowed it, and with good reason. But far from being a long-ago history that we can blithely abjure, the Crusades created a state of consciousness that still shapes the mind of the West, and if Americans don't know that, many Muslims do. We should take the president's inadvertent remark as an occasion to think about that.
Scholars count eight Crusades as having taken place in the 200-year period between 1096 and 1291. They were wars waged against Islam for control of what Christians called the Holy Land, but they also involved fierce conflict between Latins and Orthodox, and ultimately within Latin Christendom itself. It is not only that the savagery of these wars remains unforgotten in vast stretches of the world today, but also that the lines they drew remain contested borders even now - as the Balkans wars of the 1990s reveal. There are at least four key pillars of the Western mind that the Crusades put in place.
The Crusades were the first time that violence was defined by the church as a sacred act. ''God wills it!'' was the battle cry with which Pope Urban II launched the First Crusade in 1095. Anyone ''taking the cross'' to fight the infidel was offered indulgences, and, if killed, assured a place in heaven. The energy for war came from the conviction that, as President Bush put it in his address to Congress, ''God is not neutral.'' Crusaders go to war certain of God's blessing.
The crusading mind divides the world between Us and Them. Indeed, the Crusades were a deliberate effort to get Europe's princes to stop making war against each other in favor of war against an enemy outside, and it worked. The Crusades established a binding ideological consensus among Christians that led ultimately to unifying structures of politics and culture. Indeed, Europe did not become ''Europe'' until it defined itself against Islam, and that negation remains embedded in the West's self-understanding today.
But a mobilization against an enemy outside inevitably led to a paranoid fear of enemies within. Anyone not participating in the new consensus was instantly in danger. The war against Islam abroad became a war against dissent at home. That is why ''schismatics,'' or Orthodox Christians, and Albigensian heretics were soon targets of Crusades, too.
But the ultimate enemy within, of course, was the Jew. The movement from religious anti-Judaism of the early church toward the lethal anti-Semitism of modernity took its most decisive turn with the First Crusade, which was the occasion, in the Rhineland in the spring of 1096, of the first large-scale pogrom in Europe's history. Church leaders repudiated violence against Jews in subsequent Crusades, but without ever repudiating the underlying theological assumptions that made it inevitable. Leaders today decry a generalized hatred of Muslims, but the character of their war against terrorism may make it inevitable. Here are the questions this history puts to us:
Can we respond to this crisis without once more dividing the world between ''Us and Them''? Is it wise, for example, for America to insist on a global choosing of sides, what Islam can hear as the same old call to arms? Can we not more subtly enlist the support of those caught in the middle, like Pakistan's Pervez Musharraf or other Arab leaders, without igniting their populations against them?
Must we define this conflict in the cosmic - and self-justifying - language of good versus evil? As is true of every human conflict, this one is morally ambiguous. There was no ambiguity about the evil of the Sept. 11 assaults, but they arose out of a complicated set of prior conditions, some of which involve our own moral culpability. America must act in this crisis in the full knowledge of its own capacity for deadly mistakes and evil acts. America must not define self-critical moral reflection as disloyalty.
Is war our only possible response to this crisis? In addition to bringing terrorists to justice, wouldn't we do well right now to initiate a massive, long-term effort to address the ultimate source of terrorism - the radical impoverishment of millions of people, especially in the Arab world, especially in the West Bank and Gaza? Can more come from America than cruise missiles and MTV?
The only way ''this crusade, this war on terrorism,'' in the president's phrase, will not be a replay of past crimes and tragedies is if we repudiate not just the word ''crusade,'' but the mind of the Crusader. We can start by acknowledging, above all, that when humans go to war, God in no way wills it.