Glaucon’s Challenge

Book I tells us about Plato’s motivations for writing The Republic. He was worried that failure to reflect on questions about justice left his society open to ideas such as those expressed by Thrasymachus.

Glaucon formulated the official challenge that the work as a whole seeks to address at the beginning of Book II. We were especially concerned with how Glaucon’s challenge was related to Thrasymachus’s and Glaucon’s description of the perfectly unjust person.

What is the question?

The problem that Plato will try to resolve is set out by Glaucon and Adeimantus: showing that justice is worth valuing “for its own sake” rather than only being valued “for what comes from it.” Adeimantus puts the challenge in a way that tells us a lot about how Plato will try to meet it:

“No one has ever adequately described what each [justice and injustice] does of its own power by its presence in the soul of the person who possesses it, even if it remains hidden from gods and humans” (366e).

The question, in other words, is about how being just or unjust effects the soul of the just or unjust person. Plato’s answer will be that the just person’s soul is ordered while the unjust person’s is not. We will have to ask whether that is enough to show that it is better to be just than unjust.

It is natural for us to see Plato as worrying about whether justice is merely self-serving rather than being done simply because it is the right thing to do. However, I think that is not what he had in mind. Plato tried to show that the best life for you is the just life. Of course, just people will think it is self-evident that they should do what justice requires. They will say “I am doing this just because it is the right thing to do, without thinking further about my own interests.” But this makes sense, according to Plato, only if this way of thinking is part of the best life for the individual who thinks that way. We are not subject to a higher authority, so there is only the course of our own lives to consider. In that sense, justice, like everything else, is ultimately self-serving for Plato.

Glaucon and Thrasymachus

I raised several questions about Glaucon’s challenge. The most important concerned why the participants all think it is obviously a continuation of Thrasymachus’s point.

Justice, as Glaucon describes it, seems like a reasonable compromise. As Thrasymachus describes it, it’s an instrument of exploitation. Nonetheless, Plato thought it was obvious that they were both making the same fundamental point. What is it?

Will and James said that they thought it was because both Thrasymachus and Glaucon portrayed justice as second best. Audrey added one reason why Plato might have thought that was important. He was worried that injustice would be tempting to someone who thinks it is possible to get the first best by being unjust.

Still, it’s an interesting question just how much of a threat that is. Plato evidently thought it was a tremendously important one. But the rest of us might be content with something like Glaucon’s answer. It depends on what your question about justice is and what you need an answer to do.

What is a completely unjust person like?

Glaucon proposes a test to Socrates: compare the life of a completely just person with the life of a completely unjust person. Justice is vindicated only if Socrates can show that the just person’s life is better.

I asked a series of questions about the nature of this test at the end of class.

The one I spent the most time on concerned the nature of the completely unjust person. I said that I thought Glaucon characterized this person in two different ways.

  1. Someone who simply wants more or simply wants to be better than others. The unjust person, on this description, has “the desire to outdo others and get more and more” (359c, p. 35).

  2. Someone who is indifferent to the rules of justice. The unjust person “has no scruples about doing injustice” (362b-c, pp. 37-38).

I think that it makes a difference. I don’t think the first characterization is an attractive way of living to almost anyone. (I’m not even sure I understand what this sort of person even wants. Just wanting more, period, is odd.) The second characterization is much more attractive. I can see it as a real possibility for myself and so I have a question: why shouldn’t I be indifferent to justice?

At the end of the book, I am going to say that I think Plato’s arguments are successful in showing that the just life is better than the first kind of unjust life. I am also going to say that I do not think this settles the matter because he has to show that the just life is better than the second kind of unjust life as well.

Why are you spending so much time on Glaucon?

I am being fussy about Glaucon because he is the one who poses the question that the book sets itself to answer. Quite often in philosophy, the die is cast right at the beginning. The way that the question is formulated or the things that an author takes for granted at the outset lead to an answer.

You know that the magician is going to pull a rabbit out of the hat at the end. You have to be on your toes in order to see the rabbit getting stuffed into the hat. It usually happens near the beginning of the show.

Key points

Here is a list of key terms, ideas, and parts of the text. These are things that you should be able to explain after today’s class.

  1. Thrasymachus’s attack on justice
  2. Glaucon’s understanding of justice
  3. Glaucon’s division of goods
  4. The Ring of Gyges

And for fun

Glaucon’s point in three panels. And Herodotus told a similar story about a man named Gyges, without the magic ring, of course.

Finally, there is an audio version of the Republic that is available for free on iTunes as a podcast. It is surprisingly fun to listen to. More to the point, I found that listening to it helped me to understand it better.


Plato. 1992. Republic. Translated by G.M.A. Grube and C.D.C. Reeve. Indianapolis: Hackett.