Shelby White, wearing a pale green suit and a slightly tense smile, welcomed a reporter to the Park Avenue offices of the Leon Levy Foundation for an interview about the antiquities collection that has made her famous. Choice pieces are now on view, amid 7,500 other works from institutional and private lenders and the museum's own collection, in the Metropolitan Museum of Art's new Greek and Roman Galleries. The central atrium of the galleries, which opened this month, is named for Ms. White and her late husband, Leon Levy, in recognition of a $20 million gift they made to the museum.

Ms. White has rarely granted interviews about her collection. In November, Italy asked Ms. White to return more than 20 objects that it claims were looted from Italian soil, according to the New York Times. Two objects from the Levy-White collection that the Italians have sought in the past — a Euphronios krater depicting Hercules slaying Cycnos and a krater attributed to the Eucharides Painter, which depicts Zeus and his cupbearer Ganymede — are currently on view at the Met.

The Met has not been the only recipient of the couple's philanthropy: Through the years, they sponsored excavations in Ashkelon, Israel, established a fund at Harvard to support archaeological publications, and donated $200 million to start an ancient studies institute at New York University, which recently named its first director. In the interview with The New York Sun — granted on the condition that her quotes had to be approved afterward by her and her spokesman, Fraser Seitel — Ms. White shared her thoughts about the Met opening and questioned the arguments of the archaeologists who have criticized her.

Asked when she became aware that standards of due diligence in the antiquities world were changing, Ms. White responded that it was hard to say. "In the '90s, there was talk about provenance, but that meant different things" to different people, she said. "Even today, what is considered an acceptable provenance is unclear and changing."

In a study published in 2000 in the American Journal of Archaeology, the journal of the Archaeological Institute of America, the British archaeologists David Gill and Christopher Chippindale found that of the works displayed at the Met in the 1990 exhibition "Glories of the Past: Ancient Art From the Shelby White and Leon Levy Collection," 84% first surfaced after 1973. That was the year that the AIA adopted the 1970 Unesco convention on preventing illicit trade in cultural property, and, at that point, Mr. Gill said in an e-mail, museums and collectors were on notice about the problem of looting in source countries.

Ms. White questioned the basis for using the Unesco convention as a benchmark of legality. Asked what date she would suggest as a cut-off for collectors or museums, she said she didn't really have an opinion. "You could choose a date today, but would that be appropriate in 30 years? I don't know, I'm not a legal scholar."

The director of the Met, Philippe de Montebello, last year made a deal with Italy to return several disputed objects, including the Met's own Euphronios krater, in exchange for long-term loans of similar objects. But he seems to have done so reluctantly, and in his public comments, he has vigorously defended the right of museums to continue collecting antiquities. He emphasizes that museums make their collections available to many more people than governments do and that art is best seen as it is at the Met, in the context of many cultures. "We are a world museum with an international audience," he said last week, standing in the Leon Levy and Shelby White Court. "This is the patrimony of all of our visitors."

Some collectors and museum officials argue that if uncertain provenance had in recent decades kept them from purchasing works that were offered to them these objects would simply have been snatched up by other collectors, who had fewer moral qualms, and perhaps less interest in sharing their collections with the public.

The Princeton philosopher and author of "Cosmopolitanism: Ethics in a World of Strangers," Kwame Anthony Appiah, said this is a valid concern as, he said, is the argument of archaeologists that buying unprovenanced objects encourages further looting. "These are both genuine considerations: disincentivizing further looting and protecting objects that have already been looted," he said. "It's hard to do both; it's a complicated trade-off."

Now that the market for looted or unprovenanced cultural property in America has largely disappeared, Mr. Appiah said, "we have to accept that a lot of this stuff — say, in Iraq — is just going to go into Middle Eastern collections, or Japanese collections, or collections in other places where they don't have these scruples."