How can the unchangeable change?

James Carroll makes this challenging historical assertion (among many) in Practicing Catholic:

The psychological mechanism was basic: group identity followed from group threat. Humans know who they are by whom they oppose. From tribalism to nationalism, this polarity shaped human responses, with the dynamic taking extreme form in Europe after Charlemagne. What began in the Crusades [Europe learning to define itself in opposition to Islam] reached a tragic pinnacle with the wars of the twentieth century. That Europe was both the instigator and victim of those wars was the precondition of its astounding conversion, begun at the end of World War II and continuing through the end of the Cold War -- a conversion that amounted to a recognition that the East-West battle was unwinnable.

Pope Benedict saw moral rot in the fact that the magnificent churches of Europe were mostly empty, without asking why the world-historic European renunciation of violence (including the abolition of the death penalty, the condemnation of the abuse in marriage, the final end of colonialism, not to mention the Soviet empire's refusal to save itself through war) was accomplished by the generation that walked away from religion. Did that generation walk away from religion, and from Christianity in particular, because it was necessary if violence was to be fully left behind?

There's lots to quibble with in this; I imagine millions of Indo-Chinese and Algerians might have some questions about it. I could easily make a case that Europe abandoned empire only from exhaustion, ceding global hegemony to rising American power most unwillingly. Still, the idea deserves exploration that clamorous religious (ideological?) identification had to recede before more peaceful civilization became possible.

Practicing Catholic is that sort of book: thought-provoking for a wide variety of readers and ultimately gentle. By way of his personal story, Carroll makes a case that U.S. Catholics, despite the vigorous resistance of their religious authorities, have allowed their faith to evolve into a contemporary form that affirms the goodness of creation, creatures, and God Godself. It's been a tough ride, what with the Church's ongoing degradation of women, condemnation of birth control, and the hierarchy covering up for priests who abused children. But many have found liberation from a sin-obsessed self-hatred into a sustaining faith. Carroll's insistence that U.S. Catholic laity have managed this transformation is confirmed by recent polling. Despite the pope,

Catholics are more likely than non-Catholics to say that homosexual relations, divorce, and heterosexual sex outside wedlock are morally acceptable, according to an analysis by Gallup pollsters ...

There's a live and let live spirit in this.

Somehow these Catholics have lived beyond the contradiction that churns all religions that claim to offer authoritative teaching:

How does a church that claims to be unchanging change?

That's an important question for a lot of us who are not now and never have been Roman Catholic.