We talked about four questions:
Philosophers should rule because they know what is good. They both have the inclination to learn about what is really good and the ability to discover the answer. The other members of the city have neither the inclination nor the ability to know the good.
Plato’s explanation of what this involves took him on a long digression about knowledge and the forms. Plato, in The Republic, hoped that forms would solve a number of problems. I say “hoped” rather than “proved” because he didn’t think he was in a position to describe them. The most he could do is show what they might be like using an analogy. The forms are to our present mathematics as real objects are to reflected images of them.
His understanding of the Forms was heavily influenced by mathematics. When we use a diagram of a triangle to talk about the geometric qualities of triangles, we’re gesturing towards the form of the triangle: not the imperfect diagram drawn in chalk, but the abstract, perfect triangle that our proofs are about. But the forms go well beyond mathematical objects. In particular, there are forms of values: beauty, the good, and justice.
Philosophers are interested in forms. Unlike other people, they are not content to have a lot of knowledge of particular things that they get through their everyday experience of the world: “the many beautiful things are visible but not intelligible, while the forms are intelligible but not visible” (507b). This driving interest in that kind of knowledge, combined with their ability to acquire it, is what makes them exceptionally wise, according to Plato.
Going back to rule the city seems to be bad for the philosophers. Why would they do it? We did not get to this question, but since it is one of the paper topics, I thought I would note what I planned to say; we will return to this on Tuesday.
I think there are two broad reasons why the guardians would go back to rule.
There are advantages and disadvantages to each of these answers.
The first answer would explain why they would do it. But it isn’t informative: why is this is the just thing to do and how do they know that? Their acquaintance with the Forms would, presumably, make it self-evident to them that this is what they’re supposed to do. But that doesn’t explain much for us. It’s a kind of promissory note in place of an answer to Glaucon.
The second answer is more informative. But it appears to fall short of showing that justice is desirable “for its own sake.” As Plato described it, each guardian “will spend most of his time with philosophy, but, when his turn comes, he must labor in politics and rule for the city’s sake, not as if he were doing something fine, but rather something that has to be done” (540b). As I read it, each guardian’s best option is for some other guardian to rule the city. Of course, the guardians would not let one of their members off the hook: they each have to take their turn. But if that’s the way it is, then justice, defined as the guardians performing their roles, looks like a second best. It’s something that guardians do only because they have to.
The term “compulsion” is used in two different senses in our translation. The ambiguity almost certainly pervades the original greek text as well.
When Plato says that the study of mathematics “compels the soul to use understanding itself” (526b), he means that the metaphorical force of reasoning will lead to this outcome. Anyone who understands mathematics will think in this way (whatever it means to “use understanding itself”).
By contrast, when he describes the oligarchic person as holding his appetites in check “not by persuading them that it’s better not to act on them or taming them with arguments, but by compulsion and fear” (554d), he means something quite different. “Compulsion” here is not metaphorical. It involves force rather than persuasion.
Plato says that the philosophers will “go to rule as to something compulsory” (520e). Which sense does he mean there? I think that most scholars believe it is the first one: they go to rule because they are convinced that it is the right thing to do. But I am not convinced that Plato has shown that this is so.