The image of a young man running bare footed along a wall like a rampart, far, far above a busy street: "What time is it?" we call up from below. "Six o'clock," he returns, without looking at us, without missing a step.

For some reason this image keeps returning to me; I don't have Borges' story to hand, and what I remember is doubtless not quite what he wrote. But in the special case of this story, what he wrote is not important, because that story is "Funes the Memorious."