Political Philosophy Spring 2019

Justice in the City


We set out to answer a question about individual people: why should someone be just? But immediately after formulating the question, Plato takes up what appears to be a different subject: justice in a city.

Plato’s assumption is 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.

So Plato is going to try to answer four questions.

  1. What is a just city?
  2. Why is it good for a city to be just?
  3. What is a just person? (“individual” or “soul” are equivalent terms)
  4. Why is it good for a person to be just?

And he is going to try to answer these questions while also maintaining this assumption:

  1. Justice in the city is the same as it is in the individual soul.

Can he keep all five balls in the air? He comes surprisingly close! Plato is awesome.

In today’s class, I summarized the readings from Books II and III. Then we discussed the first part of Book IV.

A split among the virtues

The good city would have the four virtues of wisdom, courage, moderation, and justice. It has the first two virtues 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 the city is not courageous because everyone is courageous; it’s only the auxiliaries who are courageous (see 429b). Nor is the city wise because everyone is wise (428e). The city has these qualities because a particular class plays its role: the guardians run the city and the auxiliaries defend it. These virtues follow what I called the predominant part rule: the city has virtue V because the relevant predominant part of the city has the virtue V.

Moderation and justice are different. The city is moderate and just because, in some sense, everyone in it is moderate and just. These virtues follow what I called the part-whole rule: they whole city has virtue V because all of its parts (the individual members) of the city have virtue V.

This poses a problem for Plato. The guardians have a special role in making the city moderate and just. The whole point of the theory is that they have special ethical knowledge by virtue of their nature and training that the others lack.

This is a point where the analogy between the city and the soul seems to break down. The members of the productive class are supposed to be analogous to the desires and appetites in an individual mind. But while people can defer to the authority of the city’s “reasoning” part (the guardians), that isn’t the sort of thing that an appetite can do.

But, at the same time, Plato’s case for the guardians having authority rests on the analogy between reason and appetite in an individual mind. The city needs its rational part to be in charge of its appetitive part just as individuals need their rational part to be in charge of their appetites if they are to lead coherent lives.

Obviously, Plato needs to walk a pretty fine line in order to maintain the analogy. That is what we are going to focus on next time, when our main question is going to be whether the members of the productive classes could really be moderate or just.

Two Questions

There were two objections to Plato’s points that I wanted to make note of.

Bex asked how Plato’s myth of the metals is supposed to work. The Guardians are in charge and they are supposed to know the most. But the myth of the metals is supposed to be addressed primarily to them. It is supposed to convince them that they would not want to mix the metaphorical gold in their natures with the real stuff. So despite their power, they will remain poor rather than pursuing wealth. I think Bex is right to wonder how this is supposed to work. Are the guardians supposed to tell this story to themselves? If they know it’s a myth, it won’t work. But it’s hard to imagine that they wouldn’t know.

So it’s different from the tales that parents tell the children, such as Dylan’s example: drinking coffee will stunt your growth. The parents know it isn’t really true, but the myth can still work because they don’t have to believe it for it to work. Only the kids have to believe it. Plato’s myth would be like a story that parents tell themselves despite knowing it’s false. That doesn’t make a lot of sense.

Mary expressed doubt about an assumption that Plato is making, namely, that there could be a guardian class with superior knowledge about the best way to run the city. After all, history teaches us that most ruling classes have self-serving beliefs about how society should be run. If they believe that what they want is what is best for everyone, they are often wrong.

This kind of point can be taken in one of two ways. It might mean that even if there is a best way to run society, there is no reason to think that any ruling class would have special knowledge about what it is. Or it might mean that there is no best way to run a society. Rather, societies serve the interests of those who are in charge. (This is something Thrasymachus thinks, for what it’s worth; he might be right!) Either one poses a significant challenge to Plato.

Main points

These are the things you should know.

  1. What are the parts of the city called?
  2. What are the parts of the soul called?
  3. What is the difference between wisdom and courage, on the one hand, and moderation and justice, on the other hand, as virtues of the city?


Plato. 1997. “Republic.” In Complete Works, edited by John M. Cooper, translated by G. M. A. Grube and C. D. C Reeve. Indianapolis, IN: Hackett Publishing Company.