Political Philosophy Fall 2019

Justice in the Soul


Plato’s chief claim is that the virtues for individual people come “in the same way and in the same part” (441c) as the virtues of the city do.

In order to make good on this claim, he first has to show that the soul has parts (463a-439b) and also that the parts of the soul correspond to the three parts of the city (439c-440c).

We discussed the analogy between the city and the soul. We were particularly concerned with his description of the members of the productive class. Can they be just or not?

The City-Soul Parallel

Plato says that both the city and the soul have three parts and that those parts parallel one another.

City Part Soul Part
Guardians Rational
Auxiliaries Spirited
Productive Appetitive

But the relationship between the parts of the city and the parts of the soul goes even deeper than this. Plato says that people belong to the classes they do by virtue of which part of their soul is the predominant one. He says that “the reason we say there are three primary kinds of people” is that the rational part rules “in some people’s souls while one of the other parts … rules in other people’s” (Plato 1997, 581c). So there is more than an analogy here. Plato uses the parts of the soul to explain the division of the city into three classes. (See table 3 on the handout.)

Can the Productive Class be Just?

A thing is just, according to Plato, if all of its parts play their proper role. For instance, he says that, “the city was thought to be just when each of the three natural classes within it did its own work” (435b).

The natural parallel for individuals is to say that an individual is just if the parts of her soul all do their own work. But can this be true of a member of the productive class? That’s what we spent a fair amount of time talking about.

If we just look at the souls of the members of the productive class, we would have a hard time seeing that the parts do play their appropriate roles. In these people, the appetitive part controls the soul and the rational part is subordinate even though the rational part should govern the soul with the appetitive part being subordinate.

If we look at the way the members of the productive class participate in the city, we can see how it could make sense to describe them as being just. August, Cathy, and Tony all gave plausible descriptions of how it might work. August said that the members of the productive class could recognize the guardians as the appropriate rulers. Cathy said that the members of this class could be so focused on making money that they were not interested in usurping the guardians; as evidence, she could point to Cephalus and Polemarcus, the two merchants we met at the beginning who were happy to stick to business and avoid politics. Tony said the way Plato has described the city, each class is doing what it most wants to do, so there would be no incentive to switch into another class’s lane.

Katya raised a question about what would maintain the system. She did not think that Plato could count on the members of the productive classes to stay in their roles on their own. Rather, she thought, the guardians would need to rely on devices like the myth of the metals or brute force to do so.

Plato vs. Thrasymachus

Plato’s case for political authority rests on the inferiority of the productive class. Their souls are governed by their appetites rather than their rational part. Even if their reason were in charge, they would not have the kind of knowledge about what to do that the guardians have.

The guardians, by contrast, are governed by their rational part and they do know what is best for the city. The idea is that they act as a kind of rational part for the members of the productive class when they are in charge of the city.

At this point, Plato compares his picture of the city with Thrasymachus’s in a way that I think is revealing. Here’s what he says.

to insure that someone like that [a manual worker] is ruled by something similar to what rules the best person, we say that he ought to be the slave of that best person who has a divine ruler within himself. It isn’t to harm the slave that we say he must be ruled, which is what Thrasymachus thought to be true of all subjects, but because it is better for everyone to be ruled by divine reason, preferably within himself and his own, otherwise imposed from without, so that as far as possible all will be alike and friends, governed by the same thing. (590d)

What’s interesting is that Plato is saying that political hierarchy is good for those who are subject to it, at least, it is in a just city ruled by wise guardians. Thrasymachus had said that political rule had to be exploitative.

Whether you find Plato’s story persuasive or not, it’s noteworthy that he thought it was important to show that this is so. Thrasymachus, by contrast, either believes it’s impossible to have a non-exploitative political system or that it’s undesirable to try. Either way, he puts no weight on showing that the people at the bottom of the hierarchy benefit from it. That’s a significant difference between Plato and Thrasymachus, in my opinion.

Main Points

These are the things you should know from today’s class.

  1. What is the relationship between the parts of the city and the parts of the soul?
  2. Why is Plato inclined to say that the productive class can be just?
  3. Why is Plato inclined to say that the productive class cannot be just?


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.


There was a handout for this class: 04.PlatoJusticeSoul.handout.pdf