ROME — Forty years after the Second Vatican Council, Zenit news service is asking Church leaders and prominent laity to reflect on some of the main documents of the council.

George Weigel, a senior fellow who holds the John M. Olin Chair in Religion and American Democracy at the Ethics and Public Policy Center in Washington, D.C., regularly comments on issues of religion and public life. The papal biographer's most recent book is The Courage to Be Catholic: Crisis, Reform and the Future of the Church (Basic Books).

In the following interview, Weigel shares his thoughts about Gaudium et Spes, the pastoral constitution on the Church in the modern world.

What were the most important contributions to Gaudium et Spes?

Gaudium et Spes opened new conversations between the Church and democracy, the Church and science, and the Church and nonbelievers. Its description of the free society as having three parts — democratic political community, free economy and vibrant public moral culture, the last being the most important — was picked up and developed brilliantly by Pope John Paul II in [his 1991 encyclical] Centesimus Annus.

It's also striking that Gaudium et Spes 22 and 24 are the two most cited conciliar references in the voluminous magisterium of the present Pope. Gaudium et Spes 22 — which teaches that Jesus reveals both the face of the merciful Father and the true meaning of our humanity — is the charter of an authentic Christian humanism.

Gaudium et Spes 24 — which teaches that the fulfillment of our lives is found in self-giving, not self-assertion — is the Church's response to the selfishness and solipsism of so much of modern culture.

What was the most misunderstood part of the constitution?

It's not so much a question of misunderstanding the text as the context. Gaudium et Spes was taken to be the document in which the Church “opened its windows to the modern world.” Fair enough.

But there's another side to this: Gaudium et Spes also challenged the modern world to open its windows to the world of transcendent truth and love. A real dialogue is a two-way street. Some people forgot that in the aftermath of Gaudium et Spes.

In light of the current plague of postmodernism and deconstruction, and the demolition of any notion of “truth” with public traction, one might also ask whether Gaudium et Spes was a bit too sanguine about the main currents of late 20th-century intellectual life.

The Church is growing in the Third World but stumbling, it seems, in the West. What must the Church do in the decades ahead to win the world for Christ?

Be the Church — that is, be an evangelical movement that tells the world of God's passionate love for humanity. That, not institutional maintenance, is what the Church is for. When the Church is that, and does that, it flourishes, even in the West.

Have the scandals in the United States affected the Church's credibility?

They certainly haven't helped. But the overwhelming majority of Catholics know that the overwhelming majority of priests are good men and good servants of the Church and society.

In the post-Sept. 11 era, what particular parts of Gaudium et Spes come to the fore?

Gaudium et Spes correctly intuited that religious conviction would shape the 21th-century world. But it could not have anticipated the rise of a radical form of Islam, better styled “Islamism,” that is not interested in dialogue but in conquest — first cultural, then political.

The most comprehensive, religiously grounded counterproposal to Islamicist totalitarianism is the three-part free society mapped out by Gaudium et Spes and amplified by Pope John Paul II in Centesimus Annus.