Anne Curtis’s Silver Spring office is decorated with warm afghans and photos of her late parents, and her phone ring is set to a chime like something you’d hear in a spa. The 59-year-old nun with the blond highlights, who speaks amiably with a heavy Rah-chester accent, sounds more like the helpful minister she’s been much of her life than someone in a standoff with her pope.

Except when she’s asked how American nuns went from being the good girls of the Catholic Church — the very epitome of faithful — to the subject of headlines around the world calling them rebels.

“Well,” Curtis said, her tone curt for the first time in more than an hour of talking, “We are the church, we are the church. We are the church as much as the bishops are, as much as our lay colleagues are, as much as people who raise their children in the tradition are. That’s the church. We are all the church.”

But what exactly does it mean to be Catholic?

It’s come down to that core question in this angry year for the nation’s Catholics, with political debates about health care and the size of government jumbled up with religious ones about whether people can be good, faithful Catholics and totally ignore their bishop when he tells them to vote or pray or believe a certain way. The two sides represent seemingly incompatible visions of Catholicism, the country’s largest denomination, with one camp prizing openness and collaboration and the other championing unity of belief.

Sister Anne Curtis, of the Sisters of Mercy of the Americas. (Bill O'Leary/WASHINGTON POST)

Standing in for those visions Tuesday in a Vatican meeting room were two prominent American nuns and two prominent American bishops charged with “reforming” the Leadership Conference of Women Religious, which represents about 80 percent of the country’s 56,000 nuns.

Media across the globe have been riveted by the meeting, as are sisters who in recent weeks have been streaming to a new site, sister­, launched this spring amid a crush of news about them. After the meeting, the Vatican issued a statement that the conference “remains under the supreme direction of the Holy See” and that the goal is to channel the women toward “promoting a vision of ecclesial communion founded on faith in Jesus Christ and the teachings of the Church as faithfully taught through the ages under the guidance of the Magisterium.”

The conference said the women wouldn’t comment in detail until August, when their full membership has its annual meeting. Some close to the conference in recent months have said one option for the nuns is to form an unofficial organization that’s not directly under the Vatican.

The Vatican’s doctrine-enforcing arm released a report in April laying out the need to review, guide, and, “where necessary,” approve the work of the LCWR, which has hosted speakers who advocate against official church teachings on subjects including women’s ordination and the possibility of nondenominationalism, or “moving beyond the church.” The report also called the conference “notably silent” on abortion and same-sex marriage.

The conference’s 1,500 members represent orders including Curtis’s — the Sisters of Mercy of the Americas, which has 3,600 members. Conference leaders pushed back hard June 1, saying the report caused “scandal,” and asking for a meeting in Rome.

All sides recognize how sensitive and deep the disputes are. Catholics critical of the sisters, several experts on American Catholicism and many nuns and their leaders declined to speak publicly for this article.

As for Curtis, the idea that she’d be on the side of what European media this weekend called “the rebel nuns” is disorienting. She grew up in a big, devout Rochester, N.Y., family, was close to sisters and priests growing up and attended Catholic schools her entire life.

When she joined the Sisters of Mercy in 1975, in the years after the liberalizing Second Vatican Council, the Catholic Church seemed to her to be right in the thick of activism about every issue Americans cared about: civil rights, the Vietnam War, Watergate.

“There was this great sense for me of excitement of what it meant to be in the church — the activities, the possibilities,” she said. “The church was so much a part of looking at what was going on in society.”

And nuns were at the forefront.

Vatican II had dramatically opened Catholic life by saying laypeople, not just priests, should assume responsibility and leadership and by calling for prayer in English, not just Latin. Nuns were told to leave the security of their convents and habits and plunge into the wider culture to serve.

This meant an identity overhaul for American nuns, an army of more than 180,000 who had unique, protected status inside Catholic schools, hospitals and shelters. They were told to go back to the historic roots of their groups, or orders, and live the gospel as radically as they could.

Some historians of American Catholicism say the nuns went faster and deeper into a less doctrinaire faith because, while priests were being trained in theology, many sisters were being educated in secular subjects such as sociology and psychology.

“It was where our lives were placed — we were very much hands-on dealing with the joys and suffering of people,” Curtis said. “Our lives became intermingled with the day-in and day-out concerns of all kinds of people. That shaped us in a significant way.”

For Curtis, the council’s call led to work with pregnant young women in her home town and organizing the poor in Chile, and as a lobbyist on Capitol Hill advocating for more spending on housing and against the Iraq war. Since 2005, she has been on the small leadership team that guides the Sisters of Mercy, who work in North, Central and South America, as well as the Caribbean, Guam and the Philippines.

Leaders of her order, as well as many others, are under fire for giving platforms to ideas against the church hierarchy. While they have attracted grass-roots support across the country — a Twitter campaign with the hashtag #whatsistersmeantome has had more than 1,000 responses, and a bus tour of nuns is planned for next Monday — the nuns are standing as the most institutional symbols of a very different Catholicism than that posited by leading bishops and Pope Benedict XVI today.

“What are the Church’s pastors to make of the fact that the LCWR constantly provides a one-sided platform — without challenge or any opposing view — to speakers who take a negative and critical position vis-a-vis Church doctrine and discipline and the Church’s teaching office?” Toledo Bishop Leonard Blair, one of the priests involved in investigating the Leadership Conference, asked in a public letter on Friday. “Is it the role of a pontifically recognized leadership group to criticize and undermine faith in church teaching by what is said and unsaid, or rather to work to create greater understanding and acceptance of what the Church believes and teaches?”

To Curtis, the two sides might be too culturally different to find common ground. The women, she said, won’t do anything that’s not collaborative. “We are anything but hierarchical,” she said.

She and other sisters bristle at the idea that they are being unfaithful by exploring ideas not in line with official teaching.

“It’s our desire to learn and be open. That doesn’t mean you take everything or give up what you’re rooted in. If you know who you are, where you’re grounded — it’s the gospel, it’s God — there’s no fear. It’s actually very clarifying to do that,” she said. “The church called its people to be the church, and we’ve done that.

“You can’t put the toothpaste back in the tube.”