Glaucon’s challenge

Notes for January 23

Main points

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, what it means to value something “for its own sake,” and Glaucon’s description of the perfectly just 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 a second-best alternative. 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.

Glaucon and Thrasymachus

I raised two questions about Glaucon’s challenge. The first was: why do all the participants 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?

Ziqi and Adam both noted that Thrasymachus and Glaucon both describe justice as an artificial creation.

Mikayla and Adam also pointed out that they share the opinion that it makes the most sense to be unjust, that is, to look to cheat whenever you can get away with it.

It’s an interesting question just how much of a threat that is. Plato evidently thought it was a tremendously important one.

Finally, Dixie pointed out that neither has much use for conscience, an internal source of motivation to do the right thing. Plato, as we will see, will propose something like that when he describes the rational part of the soul (his word for ‘mind’). The rational part is supposed to regulate the parts and get them to do the right or just thing. In that respect, it is like what we call ‘conscience.’ I’m not sure that Plato saw the rational part of the soul as a source of guilt for wrongdoing, however; that may be a way in which it is different from our conception of a conscience.

Why make the effects of justice negative?

I also asked why Glaucon’s test is so severe. We are trying to see whether justice is ever desired for its own sake as opposed for its effects on one’s reputation. But why do we need to compare the life of a just person whose reputation is negative with the life of an unjust person whose reputation is positive? Why wouldn’t it be enough if the effects of being a just or unjust person were neutral? Then we could see whether one sort of life is truly better than the other.

I suspect Plato could have accepted this suggestion. The fundamental question would be the same. Why is justice desirable, apart from positive effects on one’s reputation? Suppose you would have the same reputation whether you were just or unjust. The unjust person would still reap all the benefits of injustice. What is so good about being just to counterbalance that? That’s Plato’s question.

Things you should know

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.

This page was written by Michael Green for Social and Political Philosophy, Philosophy 33, Spring 2014. It was posted January 25, 2014.
Social and Political Philosophy