Ring of Gyges

Using the ring as an example, this section of the Republic considers whether a rational, intelligent person who has no need to fear negative consequences for committing an injustice would nevertheless act justly.

In the recounting of the myth by Glaucon (Plato's older brother, as a character of the Republic), an unnamed ancestor of Gyges[4][5] was a shepherd in the service of the king of Lydia.

Glaucon asks whether any man could be so virtuous that he may resist the temptation of killing, robbing, raping, or generally doing injustice to whomever he pleased if he could do so remaining undetected.

Glaucon posits: Suppose now that there were two such magic rings, and the just put on one of them and the unjust the other; no man can be imagined to be of such an iron nature that he would stand fast in justice.

If you could imagine any one obtaining this power of becoming invisible, and never doing any wrong or touching what was another's, he would be thought by the lookers-on to be a most wretched idiot, although they would praise him to one another's faces, and keep up appearances with one another from a fear that they too might suffer injustice.