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. No man would keep his hands off what was not his own when he could safely take what he liked out of the market, or go into houses and lie with any one at his pleasure, or kill or release from prison whom he would, and in all respects be like a God among men. Then the actions of the just would be as the actions of the unjust; they would both come at last to the same point. And this we may truly affirm to be a great proof that a man is just, not willingly or because he thinks that justice is any good to him individually, but of necessity, for wherever any one thinks that he can safely be unjust, there he is unjust. For all men believe in their hearts that injustice is far more profitable to the individual than justice, and he who argues as I have been supposing, will say that they are right. 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.Socrates answered that acting unjustly was not in the self-interest of an invidual because it would throw his tripartite soul (reason/appetite/spirit) out of balance. Socrates believed justice is balancing the three parts of the soul, and that unchecked pursuit of desires upset that balance,because material desires will be pursued at the expense of wisdom. In essence, Socrates argues that it is wrong to abuse the power of the ring, and that is in itself reason enough to not abuse power.
While many people would agree with Socrates, many people will also find it hard to resist the temptation not to use the power of the ring to their advantage. And despite ultimately agreeing with Socrates that actly justly is a good in itself, I must say that I also agree with Glaucon that that the concept of justice originated as a social construct. Morality likely developed as a consequence of man's evolutionary history as a social creature in which having a sense of right and wrong and a means of punishing/discouraging unfair behavior facilitated social cohesion and cooperation between individuals who might have conflicting interests (see the Nash equilibrium).
J.R.R. Tolkien picked up on this theme in The Lord of the Rings, with Sauron's Ring of Power being that tale's equivalent of the Ring of Gyges. In Tolkien's world, no one is able to resist the temptation of the ring, with every person who wears the ring eventually being corrupted by it, including even those who have no desire to act unjustly. The solution that Tolkien proposes is not to put the ring on in the first place; to instead destroy it, so that no one can abuse it or be tempted by it.
Can this parable teach us anything today?