The controversial restoration of the interiors of a sacrosanct cathedral elicits a call to action.

Among modern architects, Chartres Cathedral, largely built in the first half of the 13th century, holds a special place. Philip Johnson famously said, “I would rather sleep in Chartres Cathedral, with the nearest toilet two blocks away, than in a Harvard house with back-to-back bathrooms.” (He first visited Chartres at age 13 with his mother, but the comparison came after he attended Harvard.) Much later, Johnson remarked, “I don't see how anybody can go into the nave of Chartres Cathedral and not burst into tears.” Frank Gehry agreed, saying in the 2005 documentary Sketches of Frank Gehry, “If you go into Chartres, it drops you to your knees.”

The cathedral is remarkable for its siting—rising like a mirage above the flat agricultural plains surrounding the town not far from Paris—and for its robust exoskeleton of flying buttresses, its striking facade of mismatched early- and late-Gothic towers, and its extraordinary collection of stone figures carved into the columns of the exterior. Its sublime interior, dark and cavernous, with jewel-like stained glass emerging from the gloom, has what Sir John Soane called the lumière mysterieuse, which he sought to emulate in his own architecture.

But today there is another reason to weep. A misguided “restoration,” under the auspices of the French government's division of Monuments Historiques, is erasing the patina of age by painting the ancient stones with white lime wash and beige paint, allegedly to recreate the 13th-century interiors. Research revealed that originally the stone was covered with a plaster surface, then painted to articulate the walls and columns, with faux stone joints that intentionally did not match the actual ones.

What constitutes proper historical restoration is not engraved in stone. While Auguste Rodin referred in 1914 to Chartres as “the Acropolis of France,” no one has repainted the Parthenon in its original gaudy blues and reds. John Ruskin avowed in 1849 it was “impossible . . . to restore anything that has ever been great or beautiful in architecture,” adding that restoration “is a Lie from beginning to end.” About the same time, Viollet-le-Duc was rebuilding many French monuments from ruins, introducing contemporary materials, such as iron, so that the new was distinct from the traces of the past. Why not leave alone the layers of history at Chartres? To erase the marks of time from the interiors—to attempt to go back to the beginning—is to destroy the poetic effect of hundreds of years of aging.

Until the cathedral's current restoration began, the interior was all of a piece, as if carved from a single rock; its power derived from the ancient floors whose stone grew like trees into massive columns, then flowed upward into the interlocking ribbed vaults. This unity is now shattered at the juncture of the antique stone floor and freshly painted columns. The juxtaposition of white columns rising just above the existing bases is an aesthetic disaster: the white makes the floor and base look dirty, jarring with the antique. Perhaps the restorers should go all the way and remove the floor and install newly cut limestone paving. After all, ancient stone floors excised from old French houses go for top dollar at high-end decorator shops in New York or London. Imagine what the original stone floors of Chartres Cathedral would fetch!

This could be the revenge of the spirit of Le Corbusier in his book Quand les Cathédrales étaient Blanches (When the Cathedrals Were White). That 1937 polemic was meant as a metaphor, to show that the rise of modern architecture was a promise of a better life, comparable to the medieval era in France, when all society worked toward a single goal, and “the cathedrals were white because they were new.” But now that Chartres Cathedral is some 800 years old, do we really need to go back to the 13th century?

To correct this travesty will require the world's attention. Critics such as Adrien Goetz in Le Figaro and Martin Filler in the New York Review of Books have pointed this out. Though Chartres is a Unesco World Heritage site, to get another organization such as the World Monuments Fund to take action, you have to nominate the monument to its watch list of endangered cultural heritage sites. So let's do it! This is a call to arms.

Alexander Gorlin is an architect with a New York City practice who writes frequently on design.