The blurry snapshot catches Leon Trotsky in mid-sentence, in Frida Kahlo’s house sometime in 1937. To the left of the frame is Natalia Sedova, Trotsky’s wife. To the right is Kahlo and, half hidden behind her, a young woman listening intently: Trotsky’s secretary Raya Dunayevskaya.
We don’t know what the argument is about but we can be sure of the premise on which it is being conducted: everybody in the photograph is a Marxist. Their ideas about politics, economics, morality and art were shaped by the writings of a man born in Germany 200 years ago.