In a brilliant lecture at the University of Regensburg last week, Pope Benedict XVI made three crucial points that are now in danger of being lost in the polemics about his supposedly offensive comments about Islam.

The pope's first point was that all the great questions of life, including social and political questions, are ultimately theological. How we think (or don't think) about God has much to do with how we judge what is good and what is wicked, and with how we think about the appropriate methods for advancing the truth in a world in which there are profound disagreements about the truth of things.

If, for example, we imagine that God is pure will, a remote majesty with whom our only possible relationship is one of unthinking submission, then we have imagined a God who can even command what seems to be irrational — like the murder of innocents. Pope Benedict reminds us, however, that mainstream Christian tradition, following its Jewish parent, has a different concept of God. The God of Abraham, Moses and Jesus is a God of reason, compassion and love, a God who comes searching for man in history, appeals to the human mind as well as the human heart and invites human beings into a dialogue of salvation.

This God cannot demand the unreasonable or the irrational. This God's revelation of himself, in the Hebrew Bible and the Christian New Testament, does not cancel out or abrogate human reason. That is why mainstream Christianity has always taught that human beings can build decent societies by attending to reason.

The pope's second point, which flows from the first, was that irrational violence aimed at innocent men, women and children "is incompatible with the nature of God and the nature of the (human) soul." If adherents of certain currents of thought in contemporary Islam insist that the suicide bombing of innocents is an act pleasing to God, then they must be told that they are mistaken: about God, about God's purposes and about the nature of moral obligation.

Responsibility for challenging these distorted views of God and the distorted understanding of moral duty that flows from them rests, first, with Islamic leaders. But too few Islamic leaders, the pope seemed to suggest, have been willing to undertake a cleansing of Islam's conscience — as Pope John Paul II taught the Catholic Church to cleanse its historical conscience.

We know that, in the past, Christians used violence to advance Christian purposes. The Catholic Church has publicly repented of such distortions of the Gospel and has developed a deep theological critique of the misunderstandings that led to such episodes. Can the church, therefore, be of some help to those brave Islamic reformers who, at the risk of their own lives, are trying to develop a parallel Islamic critique of the distorted and lethal ideas of some of their co-religionists?

By quoting from a robust exchange between a medieval Byzantine emperor and a learned Islamic scholar, Benedict XVI was not making a cheap rhetorical point; he was trying to illustrate the possibility of a tough-minded but rational dialogue between Christians and Muslims. That dialogue can only take place, however, on the basis of a shared commitment to reason and a mutual rejection of irrational violence in the name of God.

The pope's third point — which has been almost entirely ignored — was directed to the West. If the West's high culture keeps playing in the sandbox of postmodern irrationalism — in which there is "your truth" and "my truth" but nothing such as "the truth" — the West will be unable to defend itself.

Why? Because the West won't be able to give reasons why its commitments to civility, tolerance, human rights and the rule of law are worth defending. A Western world stripped of convictions about the truths that make Western civilization possible cannot make a useful contribution to a genuine dialogue of civilizations, for any such dialogue must be based on a shared understanding that human beings can, however imperfectly, come to know the truth of things.

Can Islam be self-critical? Can its leaders condemn and marginalize its extremists, or are Muslims condemned to be held hostage to the passions of those who consider the murder of innocents to be pleasing to God? Can the West recover its commitment to reason and thus help support Islamic reformers? These are the large questions that Pope Benedict XVI has put on the world's agenda. Men and women of reason and goodwill should be very glad that he has done so.

George Weigel, a senior fellow of Washington's Ethics and Public Policy Center, is the author of "God's Choice: Pope Benedict XVI and the Future of the Catholic Church." He wrote this commentary for the Los Angeles Times.