Prehistoric painting is without regard for the horizontal or the vertical: one of the horses in Lascaux is jauntily upside down, drawn by some remote ancestor of Marc Chagall. With history came uprights on horizons. The Greek and Roman love of long rectangles enclosing bas-reliefs decided for Western painting that its finiteness would be consise and rational, bounded like property, like walls and floors. This convention is still a kind of low. The old Picasso superstitiously crammed his figures into rectangles.

Guy Davenport, The Hunter Gracchus, s. 99