From Chicago comes this story about an exhibit on Catholicism — and our religion’s powerful impact on the Windy City culture. But the news about faith in the Second City is decidedly mixed:

In John R. Powers’ Chicago of the mid-20th century, there were two religions in the city: Catholics and “publics.”

“Publics went to public school, were subjected to ‘what-can-you-expect-from-public-school-kids’ glares from adults and went to different churches, which were all the same anyway,” Powers wrote in his book Last Catholic in America.

“The world,” says Powers, “was very divided.”

Not any more.

For the largely white, postwar followers of the faith, life revolved around Catholic schools, Catholic mass and Catholic celebrations such as May crownings. At Catholic Youth Organization dances, Catholic boys met Catholic girls, whom they would marry “till death do you part” in Catholic weddings, followed by the baptism of their Catholic children.

Catholics “have made such a tremendous impact,” says Jill Thomas Grannan, curator of the new “Catholic Chicago” exhibit opening next weekend at the Chicago History Museum.

Warmly nostalgic — though it includes a filmed interview with a victim of clergy sex abuse — the exhibit will be a hit, museum officials believe, drawing on the estimated 2.9 million Catholics in the Archdiocese of Chicago and the Diocese of Joliet.

But the opening of the exhibit — a cornucopia of all things Catholic, from school uniforms to vestments to Mother Cabrini’s shoes — also illustrates that, while the Catholic church is in the DNA of Chicago, it is not the dominant gene it once was.

The shift from their city enclaves to more-diverse suburbs took Catholics out of their cocoon. And, with that, the church lost some of its impact on cultural life, Powers believes.

His Catholic novels — including the best-selling Do Black Patent Leather Shoes Really Reflect Up? — are chock full of nuns and school life. But when he last visited the South Side parish of his youth, St. Christina in Mount Greenwood, he found only one religious sister. Indeed, there are 65 percent fewer nuns in the archdiocese today than in 1975, down to 2,271 — a third of whom are retired.

In 1965, there were about 450 Catholic elementary schools in the Archdiocese of Chicago, with an enrollment of 304,000; for the 2006-2007 school year, there were 217 schools, with 98,000 students.

No longer raised on first Friday masses and monthly confessions, and removed from the religious influence that informed school subjects from science to history, more and more Catholic kids assimilated into the larger world populated by “publics.”

“It’s a very different world,” Powers observes. “Neighborhoods, in general, have lost their impact. People are proud now to say they don’t know their neighbors.”

The archdiocese, bolstered by Hispanics, counts 2.3 million Catholics today — about the same as in 1965. But it acknowledges that, on a typical Sunday, only about 490,000 attend mass. And among Illinois residents who say they were raised Catholic as children, a quarter no longer consider themselves members of the faith, according to a recent Pew Forum study.

“People today consider themselves more independent” in most respects, says Jac Treanor, vice chancellor for archives and records for the archdiocese. Voters switch political parties from election to election, for example.

“Catholics today are maybe less dogmatic in adhering to traditions,” Treanor says. “There’s an open argument as to whether they’re more or less Catholic.”

Other bellwether numbers reflect the changes in the position of the church in Chicago life: In 1965, there were 550 parishes in the city and suburbs of Cook and Lake counties; today, there are 364. There were 1,344 priests 40 years ago; there are now about 830 — and 30 percent of today’s priests are retired or sick.

There’s much more to mull over at the link, so check it out.

And there’s also this sobering assessment from Andrew Greeley in the same paper:

Everything has changed. The churches are two-thirds empty on Sunday. There is, at most, one priest in the rectory. Schools and parishes have been closed, and few, if any, new ones have opened. Seminaries and scholasticates have emptied out. Cana and CFM are moribund.

The immigrant church should have segued to a post-immigrant era with some ease. It did not. On the contrary, it imploded, collapsed from the inside. Conservative Catholics blame the Vatican Council and would like to repeal it, as would many of the curial cardinals who are more or less running the church. But you cannot repeal a council because fighting the Holy Spirit is even more difficult than fighting City Hall.

The Vatican Council changed the church. We had been taught that the church could not change, should not change and would not change. Then, it did change. Everything was now under question. Many of the structures of 19th century Catholicism collapsed, most notably the central role of hellfire and mortal sin to keep people in line. Many of the church’s leaders thought the only way to end the chaos was to restore the old rules. But it was too late.

Many bishops, like all leaders at a critical time, did not do good but did the thing they do well: They made new rules and “reinstated” the old ones. They tried to restrict the sexual lives of the laity, just as they had protected the sexual lives of the abusive clergy.

A cardinal once said to me, “If only Cardinal Meyer had not died.” He was right that Albert Meyer had the intelligence, the spiritual depth, the courage, the flexibility and the stubborness to have led the church in this country, and this city, through the crises. We did not see his like again. Laity and clergy decide for themselves what is morally wrong and what is not. Bishops insist on the rules, and no one listens. There does not seem in the short run any way out of the mess, though it is patent that rules and lists of sins will not do the trick.

For more on the exhibition at the Chicago History Museum, just visit their website.

Photo: Sisters of St. Joseph ride in a new car Dec. 10, 1966. The car was a gift of St. Barbara’s parish of Brookfield, which purchased the car with trading stamps. From the Chicago Sun-Times Library.