The Republic

Socrates believes he has adequately responded to Thrasymachus and is through with the discussion of justice, but the others are not satisfied with the conclusion they have reached. Glaucon, one of Socrates' young companions, explains what they would like him to do. Glaucon states that all goods can be divided into three classes: things that we desire only for their consequences, such as physical training and medical treatment; things that we desire only for their own sake, such as joy; and, the highest class, things we desire both for their own sake and for what we get from them, such as knowledge, sight, and health. What Glaucon and the rest would like Socrates to prove is that justice is not only desirable, but that it belongs to the highest class of desirable things: those desired both for their own sake and their consequences.

Glaucon points out that most people class justice among the first group. They view justice as a necessary evil, which we allow ourselves to suffer in order to avoid the greater evil that would befall us if we did away with it. Justice stems from human weakness and vulnerability. Since we can all suffer from each other's injustices, we make a social contract agreeing to be just to one another. We only suffer under the burden of justice because we know we would suffer worse without it. Justice is not something practiced for its own sake but something one engages in out of fear and weakness.

To emphasize his point, Glaucon appeals to a thought experiment. Invoking the legend of the ring of Gyges, he asks us to imagine that a just man is given a ring which makes him invisible. Once in possession of this ring, the man can act unjustly with no fear of reprisal. No one can deny, Glaucon claims, that even the most just man would behave unjustly if he had this