The arches at the top of the Carmo Convent carry nothing. They spring, they curve, they meet at the crown, and then there’s sky. Everything they were built to hold came down on 1 November 1755, and nobody put it back. Look closely at the roofline and you’ll see scaffolding tucked between the bays, which is the detail that gives the game away: somebody is paying to keep this building broken.

The guide in the purple cardigan has a microphone curled against her cheek, and the young man in the grey hoodie has a receiver tucked in his ear. Between them hangs a painting that could have used her in 1893. When Paul Gauguin’s Arearea first went on show in Paris, it carried a Tahitian title almost nobody in the gallery could read. No one stood beside it to explain. Gauguin painted it in 1892, about a year after he sailed for Tahiti looking for a way of life he thought Europe had lost.

A man in a black jacket stands in front of it with his hands in his pockets. A woman walks past without looking. This happens all day, every day, in the French rooms on the second floor of the Met, and almost nobody stopping there knows they are looking at the most argued-over label in the building. The picture itself is calm enough. A young woman sits with a drawing board on her knees, in the white tunic every fashionable woman in Paris was wearing in 1801, red drapery bunched on a chair behind her.

Michelangelo Merisi da Caravaggio arrived in Rome around 1592, at approximately 21, with no money, no connections, and a technique nobody in the city had seen before. He was dead by 1610, at 38 or 39, on a beach in Porto Ercole, probably of fever, possibly of lead poisoning from his own pigments, possibly of something worse. In between, he produced roughly 80 paintings that broke Western art into a before and an after — and killed a man in a street brawl, fled Rome as a fugitive, killed or badly wounded at least one other person in Malta, and spent the last four years of his life on the run from a papal death warrant.

Thomas Bruce, the seventh Earl of Elgin, arrived as British Ambassador to the Ottoman Empire in 1799 and left, between 1801 and 1812, with approximately half the surviving sculptural decoration of the Parthenon. This is the basic fact around which everything else — the legal argument, the cultural argument, the moral argument, the counter-argument, and the occasional productive silence — has been organized for the better part of two centuries.

Johannes Vermeer lived 43 years, fathered fifteen children, worked as an art dealer to support them, and left behind approximately 36 paintings. The number is not certain — attribution disputes move a few canvases in and out — but the range has never extended far past 40 in either direction. For a professional painter of the Dutch Golden Age, this is an almost implausibly small body of work. His contemporary Jan Steen produced over 800 paintings.