In the Pool Room at The Four Seasons, August 1959. Photo: Bettmann/Corbis

Holy moly! Aby Rosen, the owner of the Seagram Building, was about to despoil the pristine interior of The Four Seasons Restaurant when the Landmarks Preservation Commission yanked the sledgehammer from his fist. Or: Argh! Aby Rosen, hoping to nudge a venerated but tired restaurant back to life, asked to make a few design tweaks, but intransigent bureaucrats shackled him to the status quo.

Disputes over landmarks usually present themselves as a conflict of caricatures. Preservationists decry barbarian businessmen plundering the past. Those seeking to alter or demolish a venerable building dismiss objectors as fusty antiquarians willing to sacrifice prosperity and jobs for a bit of crumbling plaster. Unfortunately for simple narrative, the moral dichotomies of preservation are often bogged down in technical minutiae. The most important decisions are made in a swamp of ambiguity.

In the most recent battle, Rosen petitioned the Landmarks Preservation Commission to make several changes to The Four Seasons, the Seagram Building’s lobby-level restaurant designed by Philip Johnson in 1958 and accorded landmark status in 1989. Rosen wanted to change the carpeting, which the LPC allowed. He also wanted to remove a crackle-glass partition and make another walnut-paneled partition movable. The commission wisely said no.

Photo: Jemal Countess/Getty Images

That conclusion was not self-evident. Would the changes have ravaged the space, destroyed its historical value, or made a mockery of preservation? Not really. But the ruling matters precisely because Rosen made relatively modest requests, and still the commission saw them as violations of its trust: to protect design that has outlived its most efficient self. The case was a test of the commission’s willingness to stand up to an influential and relentless developer who acts as though the very fact that he’s chosen to spend his money on something makes it by definition good.

To the 99.99 percent of New Yorkers who never have and never will have a meal at The Four Seasons, these questions seem like the precious, fussy quibbles of an irrelevant elite. There are, after all, more urgent and sweeping questions about the city’s ability to retain its old imperfections in the face of aggressive “improvement.” Also, those who believe that good design should be flexible have little patience with intransigent purists. Architecture, unlike less practical forms of art, is subject to constant revision, long after its creators have vanished. What is original does not always remain useful; what no longer works must be defended on subjective aesthetic grounds, which is never a powerful strategy. It’s precisely because there are so many arguments in favor of abusing the past that preservation becomes so crucial.

This spring we celebrate the 50th anniversary of New York’s landmarks law, which takes as its creation myth the outrage visited upon Penn Station in 1963. Today, preservation is usually a murkier business. The city’s 114 protected interiors are especially vulnerable to renovation creep, for several reasons. The LPC cannot dictate how a building is used, spaces can be adapted to a business’s practices more easily than the other way around, and the law is a Swiss cheese of loopholes. To see exactly how permeable the statute is, pop into 374 Fulton Street in Brooklyn, where the interior of the restaurant Gage & Tollner, with its wood paneling, velvet walls, and soft gaslight glow, has been a landmark for 40 years. Except that the restaurant is long gone (it’s now a cheap-clothing-and-costume-jewelry store), the space is luridly lit, and the luxuriant walls are hidden behind gimcrack panels. In a small consolation to anyone who treasures its Gilded Age glories, the interior remains technically intact, in the same way a Mayan city lies undiscovered in the jungle.

The Four Seasons is a modernist landmark, which raises another bramble bush of thorny questions. For a modern building to remain functional, its substance must sometimes be scrapped. Woe betide the restorer who strips antique wood paneling from a landmarked 19th-century room, but a leaky glass curtain wall from the mid-20th century can’t be patched with epoxy; it must be replaced with its technologically superior equivalent. In that gap between the sanctity of the design and the provisional quality of the stuff itself, uncertainty flourishes like mold.

The LPC’s rejection of Rosen’s changes is a shot of disinfectant clarity. He may control The Four Seasons but the public owns it, and if the restaurant is a relic of superannuated fanciness, then that’s precisely why we value it. The city evolves all around, customers have ever-more specific desires, the economy imposes fresh pressures, and chefs sport new sets of needs. But while Gage & Tollner is a sad monument to expediency, the commissioners saw that, at least for now, The Four Seasons can endure as a beautiful repository of memory and a reminder of inalienable glamour.