Ring of Gyges

Excerpts: Wikipedia & Freakonomics (book)

"Gyges of Lydia was a shepherd. One day after an earthquake, a cave was revealed in a mountainside where Gyges was feeding his flock. Entering the cave, Gyges discovered that it was in fact a tomb containing a corpse, which wore a golden ring, which Gyges pocketed. He discovered that the ring gave him the power to become invisible by adjusting it. Gyges used this new power of invisibility to seduce the queen, and with her help he murdered the king, and became king of Lydia himself."

Glaucon after hearing this story argued with Socrates that any man who could gain such a power would be incapable of being virtuous enough to resist any form of temptation. He said that morality is only a social construction, the source of which is the desire to maintain one's reputation for virtue and honesty. And hence, if that sanction were removed, one's moral character would evaporate. And adds that If anyone so happens to obtain this power, and that if with such power he/she never does anything wrong or touches what is another's, he/she would be thought by the on-lookers to be a most wretched idiot.

Socrates, however, explains that the man who abused the power of the Ring has become morally bankrupt and suffered irreparable failings of character, while a man that chose willingly not to use it is at least at peace with himself.