Almost everything most people know about art, they know from reproductions. Not from standing in front of the object, but from a plate in a book, a slide in a lecture hall, a poster on a wall, a screen. André Malraux gave that condition a name in 1947 and called it the museum without walls: a collection nobody owns, assembled out of photographs, in which a Sumerian seal and a Gothic tympanum and a Florentine marble sit on facing pages as equals.