Full disclosure, up front: Archbishop Charles Chaput of Denver is an old friend; the Archdiocese of Denver syndicates this column to Catholic papers throughout the country; I played a (very) minor role in introducing Archbishop Chaput to my friends at Doubleday.

So I'm not exactly a disinterested party in the matter of the archbishop's new book, Render Unto Caesar: Serving the Nation by Living Our Catholic Beliefs in Political Life. I trust that doesn't preclude my suggesting that it's essential reading for serious Catholics in an election year fraught with consequence for core Catholic issues in 21st century America.

Archbishop Chaput is a pastor, first and foremost; his book is a pastor's book. It's informed by scholarship, and by the archbishop's extensive experience in wrestling with issues at the intersection of morality and public policy.

At the same time it's a book for ordinary Catholics who want to be faithful to the Church and faithful to the first principles of justice in their civic lives. Here's the argument, concentrated into nine key points.

1. Schizophrenic Catholicism is neither Catholic, nor responsible, nor patriotic. "We have obligations as believers," the archbishop writes. "We have duties as citizens. We need to honor both, or we honor neither."

2. Postmodern secularist skepticism about the truth of anything is soul-withering; in C.S. Lewis's phrase, it makes "men without chests." The current social, political and demographic malaise of aggressively secularist Europe is an object lesson, and a warning, for America: "A public life that excludes God does not enrich the human spirit. It kills it."

3. The new anti-Catholicism in the U.S. is not built around antipathy to the papacy, the sacraments, consecrated religious life, or the other bugaboos of those who once ranted about the "Whore of Babylon." Rather, it's an assault on religiously informed public moral argument of any sort, an attack against "...any faithful Christian social engagement." So we can't rest easy with the fact that the Catholic Church plays a considerable role in American society. There are forces in the land that would banish Catholicism, and indeed classic biblical morality, from a place at the table of democratic deliberation.

4. Because the Catholic Church's defense of the first principles of justice -- principles that can be known by reason -- has specific policy implications for public life, the Church's teaching has political "side-effects." Anyone who considers this partisan meddling is simply mistaken. The most powerful "political" statement Catholics and other Christians make is to acknowledge the sovereignty of Christ as the first sovereignty in our lives. This confession of faith in fact helps make democracy possible, by erecting a barrier against the modern state's tendency to fill every nook and cranny of social space.

5. America was founded on the convictions that there are moral truths that we can know by reason, and that the state has no business doing theology. The result was the vibrant, religiously informed public moral culture that amazed Alexis de Toqcueville in the 19th century. That distinctive American experience later shaped Vatican II's teaching on religious freedom and the limited, constitutional state.

6. Work for social progress, however noble, is no substitute for ongoing personal conversion to Jesus Christ. True conversion will almost inevitably extract costs in politics. Catholic politicians who seek to avoid these dilemmas by hiding in the underbrush of a public square stripped of religious and moral reference points should reflect on the lives of Thomas More and Martin Luther King.

7. There is a bottom line in all this: the life issues are "foundational ... because the act of dehumanizing and killing the unborn child attacks human dignity in a uniquely grave way."

8. Responsible citizenship means making choices, not simply voting the way our grandparents did. Citizenship is an exercise in moral judgment, not in tribal loyalty.

9. Nothing in politics is perfect, including candidates. Yet unless we fight for the truth, "we become what the Word of God has such disgust for: salt that has lost its flavor."

Good stuff. Buy one yourself; buy another for a friend.

-- George Weigel is Distinguished Senior Fellow of the Ethics and Public Policy Center in Washington, D.C.