Justice in the city

We set out to answer a question about individual people: why should someone be just? But immediately after the question had been formulated, we took a detour and started talking about what justice in a city. The assumption was that justice is the same in the city and the individual soul, such that a description of justice in the city would help us to answer our original question about justice in the individual.

I summarized the readings from Books II and III. Then we discussed the first part of Book IV.

Wisdom and courage

The ideal city would have the four virtues of wisdom, courage, moderation, and justice. It has each virtue because of the roles played by the different classes. For instance, the city is wise because it is ruled by the class that knows the most about what is good and is the most dedicated to the city: the guardians. And it is courageous because the auxiliaries are in charge of their defense.

Note that it is not courageous because the auxiliaries make everyone courageous (see 429b, for example). Nor is it wise because everyone is wise. The city has these qualities because a particular class plays its role: the guardians run the city and the auxiliaries defend it. As we will see, Plato did not think the members of the productive class were especially wise or courageous.

We spent some time talking about why Plato might have thought that people who are good at business or military affairs would not be good leaders for the society as a whole.

Moderation and justice

The two big virtues are moderation and justice. Plato’s account of moderation in the city begins with the individual: moderate individuals control their desires such that the “naturally better part” of the soul “is in control of the worse” (431a). Similarly, in the city, “the desires of the inferior many are controlled by the wisdom and desires of the superior few” (431d). At the same time, he said that in the city “moderation spreads throughout the whole” producing “agreement between the naturally worse and the naturally better as to which of the two is to rule” (432a).

The city was thought to be just “when each of the three natural classes within it did its own work” (435b). It is not easy to see how justice and moderation differ from each other.

I said that I saw how Plato thought he had shown why the city he is describing is good: the people in a just city all do what they are best at and that has to be better than their doing what they are not so good at. But it is not obvious to me why this is a just city. Everyone in this city keeps to their place. But why does that mean they will do the things mentioned in Books I and II as examples of just behavior: telling the truth, performing their contracts, and so on?

Key terms

  1. The parts of the city
  2. The parts of the soul
  3. The virtues of city and soul


There was a handout for this class: 03.PlatoJusticeCity.handout.pdf