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.

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.