NEW YORK — In the Morningside Heights section of Manhattan, near Columbia University, stands a blocky 19-story limestone tower known to some as the “God Box.”

Opened in 1960, the Interchurch Center (as it’s really called) stands today as a monument to the now-faded swagger of midcentury American liberal Christianity. These days, it houses a mixture of religious and secular offices, including one where people were gathered around a table on a recent afternoon debating the nature and fate of another midcentury phenomenon: the Commonweal Catholic.

Commonweal Catholics were educated, liberal-minded and middle-class, and aspired to assimilate into elite culture while bringing their Roman Catholic faith, education and sensibility with them.

And today?

“The term isn’t as definite as it used to be,” said Matthew Boudway, senior editor of Commonweal magazine, which gave the type its name. But to him, it means being liberal in politics and theology, while also “thinking too hard” about how faith and the rest of your intellectual life mix.

Dominic Preziosi, the magazine’s editor, also at the table, laughed. “Sometimes way too hard,” he said.

The old-style Commonweal Catholic may no longer quite exist. But Commonweal magazine, which describes itself as the nation’s oldest independent lay-edited Catholic journal of opinion, is still very much here. And this fall, it is celebrating its 100th birthday with a gala, an anthology of its interviews over the years with prominent figures (Jorge Luis Borges, Reinhold Niebuhr, Martin Scorsese) and a 100-page centennial issue.

But this being Commonweal, there are also tough, tangled questions, starting with a big one: What does it mean to be a leading intellectual voice of liberal Roman Catholicism at a moment of continuing loss of faith in both the church and liberalism?

Today, attendance at weekly Mass continues its decades-long decline. There are sharp political divisions in the pews and in leadership, while the ranks of newly ordained priests are trending overwhelmingly conservative, theologically and politically. And in the intellectual realm, conversation is dominated by conservative Catholic “postliberals” who argue that liberal individualism has eroded culture and community. Some call for a toppling of current elites — or even an end to the separation of church and state.

But to admirers, Catholic and not, the magazine remains a stalwart defender of a liberal Catholic intellectual tradition that is embattled but hardly dead.

“Commonweal stands for the common sense of American Catholics in the laity,” said Samuel Moyn, a professor of history and law at Yale who has contributed to the magazine.

“In the intellectual space, a few reactionaries have sucked up the attention,” Moyn continued. “But Commonweal is in a sense more representative of where American Catholics are by and large.”

Exactly where American Catholics are politically is a matter of much debate in this year’s election, where recent polls show Catholics overall (and white Catholics in particular) leaning toward former President Donald Trump. But Preziosi said he believes the magazine speaks for more people than its circulation of about 15,000 might suggest.

“We are a small voice among many voices,” he said. “But I think we do give voice to a certain kind of person who yearns for a Catholicism that recognizes the complexity of many issues, who knows they can’t be reduced to simple slogans or devotional pieties or visions of a better past.”

Commonweal was founded in 1924, as a kind of Catholic version of The New Republic. The first editor, a former socialist named Michael Williams, described the goal as representing “the Catholic outlook on life and the Catholic philosophy of living” to “the whole of the American people.” Over the decades, contributors have included such illustrious names as Dorothy Day, Thomas Merton, Hannah Arendt, Graham Greene, W.H. Auden and John Updike.

In the 1930s, during the Spanish Civil War, the magazine’s failure to side with Francisco Franco, who was strongly supported by American Catholics, cost it a fifth of its subscribers, an editor later estimated. Later, it took heat from some coreligionists for its criticisms of Sen. Joseph McCarthy.

Commonweal’s circulation peaked at nearly 50,000 in the late 1960s, when it championed the liberalizing reforms of the Second Vatican Council. Its editors also opposed the Vietnam War and pushed for greater redistribution of wealth. In 1973, on the eve of its 50th anniversary, the magazine’s editor, James O’Gara, described its mission as “nothing less than a total reorganization of the church and society.”

Status update? “Ask us in 100 years,” Preziosi said.

Commonweal’s spare, 800-square-foot office is dominated by a long table where staff members, by tradition, eat lunch together every day. On that recent afternoon, a half-dozen editors batted around more thoughts on what defines a 21st-century Commonweal Catholic: politically engaged, with social democratic views about politics and the economy, broadly committed to the legacy of the Second Vatican Council.

These days, the magazine runs plenty of articles about theology and church affairs, like a 2020 issue on the demographic and geographic shifts in American Catholicism and a recent group of essays supportive of ordination of women priests. (The magazine also published a dissent.)

The magazine has been broadly supportive of Pope Francis’ efforts to make the church more inclusive, and publishes a range of views on abortion. In 2022, after the Supreme Court overturned Roe v. Wade, it ran an editorial that did not directly praise or criticize the decision, but lamented how church leaders’ narrow, unbending approach had made the pro-life cause “a tool of the right.”

But there are also articles on art and culture that have no particular Catholic imprint. Among its most-read recent articles, Preziosi said, is a review by Dorothy Fortenberry of a recent memoir about polyamory, which she read (compassionately) as a narrative of sadness.

Fortenberry, a playwright and television writer whose credits include “The Handmaid’s Tale” and the climate-change drama “Extrapolations,” grew up only vaguely aware of Commonweal, as something her grandmother subscribed to. She said she appreciates its “unpredictability,” and the way it “avoids the temptation to dunk on anybody” or force conclusions.

“The commitments of Catholicism don’t line up very neatly on contemporary politics,” she said. “At its best, the magazine can create space for ideas to bounce around.”