The Ring of Gyges . It grants its owner the power to become invisible at will. Through the story of the ring, Republic considers whether an intelligent person would be just if one did not have to fear any bad reputation for committing injustices.
The legends
was a historical king, the founder of the Mermnad dynasty of Lydian kings. Various ancient works—the most well-known being The Histories of Herodotus—gave different accounts of the circumstances of his rise to power. All, however, agree in asserting that he was originally a subordinate of King Candaules of Lydia, that he killed Candaules and seized the throne, and that he had either seduced Candaules' Queen before killing him, married her afterwards, or both. In Glaucon's recounting of the myth, an unnamed ancestor of Gyges was a shepherd in the service of the ruler of Lydia. After an earthquake, a cave was revealed in a mountainside where he was feeding his flock. Entering the cave, he discovered that it was in fact a tomb with a bronze horse containing a corpse, larger than that of a man, who wore a golden ring, which he pocketed. He discovered that the ring gave him the power to become invisible by adjusting it. He then arranged to be chosen as one of the messengers who reported to the king as to the status of the flocks. Arriving at the palace, he used his new power of invisibility to seduce the queen, and with her help he murdered the king, and became king of Lydia himself.
In Republic, the tale of the ring of Gyges is described by the character of Glaucon who is the brother of Plato. Glaucon asks whether any man can be so virtuous that he could resist the temptation of killing, robbing, raping or generally doing injustice to whomever he pleased if he could do so without having to fear detection. Glaucon wants Socrates to argue that it's beneficial for us to be just apart from all considerations of our reputation. Glaucon posits: Though his answer to Glaucon's challenge is delayed, Socrates ultimately argues that justice does not derive from this social construct: the man who abused the power of the Ring of Gyges has in fact enslaved himself to his appetites, while the man who chose not to use it remains rationally in control of himself and is therefore happy.
Cultural influences
Cicero retells the story of Gyges in De Officiis to illustrate his thesis that a wise or good individual bases decisions on a fear of moral degradation as opposed to punishment or negative consequences. Cicero follows with a discussion of the role of thought experiments in philosophy. The hypothetical situation in question is complete immunity from punishment of the kind afforded to Gyges by his ring.
In the first canto of Orlando Innamorato, Galafrone, king of Cathay, gives his son Argalia a ring which makes the bearer invisible when carried in one's mouth and which protects against enchantment when worn on one's finger.
Jean-Jacques Rousseau, in his "sixth walk" from his 1782 Reveries of a Solitary Walker, cites the Ring of Gyges legend and contemplates how he would use the ring of invisibility himself.
H. G. Wells' The Invisible Man has as its basis a retelling of the tale of the Ring of Gyges.
The One Ring from J. R. R. Tolkien's The Hobbit and The Lord of the Rings grants invisibility to its wearer but corrupts its owner. Although there is speculation that Tolkien was influenced by Plato's story, a search on "Gyges" and "Plato" in his letters and biography provides no evidence for this. Unlike Plato's ring, Tolkien's exerts an active malevolent force that necessarily destroys the morality of the wearer.
