In a Roman recycled version of a Greek myth, the Sicilian tyrant Dionysius II has the fawning courtier Damocles enjoy the luxury of a fancy banquet, but with a sword hanging over his head, tied to the ceiling with a single hair from a horse’s tail.1

1. Taleb, Nassim. Antifragile: Things That Gain From Disorder. New York: Random House, 2012.