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.
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.
As Helena remarked, it is natural for us to see Plato as worrying about whether justice is merely self-serving rather than genuinely being done for the sake of others. 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. So justice, for Plato, is ultimately self-serving.
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?
Aaron said that he thought it was because they both portrayed justice as second best. The worry was that this would be tempting to someone who wanted the first best: the tyrant or completely unjust person.
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.
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.
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.