THE OLD ORDER changeth -- even at the Vatican

Despite denials that a major cultural offensive is underway, an exhibition of Vatican treasures is opening in New York at the Metropolitan Museum on Feb. 26--and it took a lifting of Pope Paul VI's 1965 ban on all loans of "monuments and works of art" abroad to do it.

"This is an exception," says Walter Persegati, secretary-treasurer of the Vatican Museums.

If so it is a most exceptional exception to a rule established in the furor following the shipment of Michelangelo's "Pieta" to the 1964 New York World's Fair. At the time, art historians all over the world joined angry Italians in arguing that such a risk was not worth taking.

This exhibition contains no Michelangelo, but it does put at risk 237 treasures spanning the ages, from the splendid Belvedere Torso from 1st century B.C. Athens to paintings by Leonardo da Vinci and Caravaggio.

Have the dangers of shipping 54.7 tons of art in 11 Pan Am planes--and repeatedly unpacking and repacking them--suddenly disappeared?

Says Persegati, "The "Pieta" traveled more than 15 years ago, and since then packing, handling and shipping systems have improved materially, and relative humidity can be kept under control. An airplane could still go down, but even airplanes are better."

Besides, he says, the ultimate responsibility was not his. "The final decision was made by the pope."

Given the risks, exceptions and history of controversy, does this represent a campaign to introduce the Vatican's art treasures to the world?

"It is part of changing moods in the Vatican," says Persegati. "There is, in the present pope, the need to reach out and touch people, to communicate, and this is a natural way to do it. After all, this exhibition will speak not only about art, but about the popes and the church and religious values."

If this is not a policy change, many people have perceived it as such. Persegati says that news of the show has prompted requests for similar loans all over the world. Rumors abound.

"We don't know what the future will bring," he says. "At the moment there is a lot of talking, but nothing cooking. We shall see."

Last summer 78 modern works from the Vatican collections were loaned to Helsinki, a show that Persegati says "had tremendous success," bringing in more than 60,000 people.

"That was an exception, too," he says.

Clearly something has changed in Vatican City, where art activity has been accelerating rapidly over the past few years:

* A stepped-up exhibition program at the Vatican, including shows on Bernini, Vatican restoration projects, American paintings and American crafts.

* A series of symposiums and lectures to accompany these shows.

* A stepped-up educational program, including audio-visual aids for the visiting public, to be launched within the next few months.

* The premier showing, next September, of the American paintings collection of Baron Hans Heinrich Thyssen-Bornemisza. This will be the first stop on a tour of several European and American museums.

* A deal with the Nippon Television Network Corp. of Japan, under which Nippon provided $3 million for cleaning the walls and ceilings of the Sistine Chapel in exchange for first rights to film the 12-year restoration project.

Monsignor Eugene V. Clark, aide to Terence Cardinal Cooke, archbishop of New York and liaison with the Vatican for the Met show, suggests an entirely earthly reason for the exceptional change of heart: "The Vatican Museum is in the red and the Vatican altogether is having fiscal problems, so you can imagine what a problem the museum has getting funds. There are 10 different museums there--a great burden they've carried alone all these years.

"But mostly it's not the money but the good will, and part of their traditional policy of preserving and sharing," Clark says. "They know what they have, and are pleased for a chance to let others see it; so many countries have destroyed art in civil wars and other horrors. Nothing given to the Vatican has ever been destroyed. Napoleon hauled off some treasures, but they came back. There never has been an ideology in Rome that would destroy these things; they took as good care of pagan Roman art as Christian things.

"They are aware that there is some danger in moving a piece, but my guess is that if you asked 'Is it worth losing a piece once in a while to share with millions of people?' they might say yes. I don't know."

The cost of the exhibition is a reported $8 million. But Clark says, "The whole enterprise will cost the Vatican virtually nothing, except the risk. The Met took full responsibility for the cost. Philip Morris has contributed $3 million--the largest corporate gift ever made to an art exhibition. Pan Am gave free transportation valued at $500,000 . I know the people at Pan Am, and said, 'Here's a great idea for you.' Within a week, they agreed."

Other donors for the New York showing include: Manufacturers Hanover Corp., Merrill Lynch, Pierce, Fenner & Smith Inc. and the Robert Wood Johnson, Jr. Charitable Trust. Still others have underwritten the showings in Chicago and San Francisco.

What does the Vatican get to keep?

"They get a percentage of catalogues, posters and other items being sold, but it won't amount to $1 million or anything like that," Clark says. "They also got over $500,000 toward the cost of getting all those pieces restored--something the Vatican museums didn't have the money to do."

The restoration money is clearly of major importance to Persegati, who says the Vatican used it to "restructure the restoration laboratories and to buy a lot of equipment. Actually, we spent double that."

The source of the additional funds is "my secret," Persegati says, though he acknowledges that Thyssen-Bornemisza was among the contributors. (Oddly enough, the thrice-married baron is an excommunicated Catholic.)

"We had a very competent staff, but we needed equipment," says Persegati. With the money from the Met, the Vatican restoration labs--including those specializing in paintings, sculpture, textiles, ceramics, bronze and wood--purchased an environmental chamber to accustom wood panels to the air-conditioned setting of American museums; and X-ray equipment and microscopes. "We had the people; what we needed was the technical means. We hope to continue to expand these efforts."

It is ironic that the travel ban on art was issued by the art-loving Pope Paul VI, who set the stage for this subsequent activity.

After a 1964 papal announcement that the Vatican would welcome modern art with spiritual--but not necessarily religious--content, a committee called The Friends of American Art in Religion was founded to help the Vatican acquire American pieces.

The American committee, especially its president, Cardinal Cooke, played a crucial role in preparing the way in high places for the loan to the Met. The committee also hosted the preview dinner at which Nancy Reagan pronounced the show "spectacular."

"Paul VI was very interested in art, and wanted to build a bridge between living artists and the church again," says New York art dealer Lawrence K. Fleischman, vice president of the Friends panel--which he says he dreamed up. "Paul VI commissioned Manzu to do a beautiful little chapel, and new bronze doors for St. Peter's. I met Paul VI many times. In fact he knighted me: I'm a Jewish Knight of the Order of St. Sylvester.

"I'm not Catholic--a lot of us aren't," Fleischman says, "but the interest was in promoting American art, and the Vatican took the broad approach--not trying to push Catholicism or anything. Together the group has helped the Vatican acquire many American works by Leonard Baskin, Lipchitz, Feininger, Evergood, and a whole room of Ben Shahn. Some things I gave personally. No funds came from the Vatican; private funds were always found."

Now the Vatican's traditional holdings have come to America. A month of previews has been set aside for the 70,000 members of the museum, prior to the Feb. 26 public opening.

"We want our collections to be more known, and our message to be more understood," Persegati says. "We have sent all prima donnas, and together they are not just individual beauties, but a whole choir. At the Vatican, 1.7 million visit the museums in one year. During this tour, we expect 3 million. Americans may or may not have the chance to come to Rome, but I think more will come, and they will realize that the Sistine Chapel is not the only thing to see."

Explicit or not, a decision obviously has been made somewhere in the Vatican to risk a bit of the past to guarantee the future of its museums.