If only Plato had lived to witness the arrival of the internet, he would have realized that the twenty-fi rst century has given an entirely new signifi cance to a story he told in Book 2 of his Republic: the story of the Ring of Gyges. Gyges is a shepherd in the service of the king who, following a storm and earthquake where his fl ock is feeding, looks down into a chasm that has opened up in the ground, and sees there a bronze horse and within it the body of a man, wearing nothing but a ring. He takes the ring, puts it on and, by chance while at a meeting with his fellow shepherds, fi nds that by turning it he becomes invisible and then by turning it back becomes visible again. Arranging to go to the court as a messenger, he uses this new power of invisibility to seduce the queen (we are not told how this is achieved, but it would be intriguing to know the sexual attractiveness to be found in invisibility!) and, with her help, to kill the king and take the throne. Plato’s point in recounting this story is to compare the just and the unjust person, supposing that there were two such rings and one were given to each. e fundamental question is this: would you retain your moral principles if you knew that you could take whatever you liked with impunity? Would you resist the temptation to use that power to enhance your own position? Are we kept moral only by fear of consequences?