Thrasymachus' view about justice close to Callicles' in Gorgias: real justice is, a la Thucydides on Melos, for the 'stronger to do what they can and the weak to suffer what they must'.
Socrates' response: the virtue of justice must be the interests of the ruled, as shepherding is the interests of sheep, not shepherds.
But Glaucon unsatisfied: proposes justice as an agreement--if we could do what we could, we would and would act unjustly--but if we tried to, everyone would do worse, so we agree to laws, and those are just.
Glaucon's argument for justice as agreement, not something valued for itself: the ring of invisibility.
Socrates' response: parallel between soul and city: there's justice in soul of individual, and also in the city. The city, larger, helps us see the parallel justice in the soul, and that will help refute Glaucon's ring of invisibility argument.
Note: we're talking about the workings of a city here in the Athenian context.
So what's the just way to run a city? Socrates' method is to start with a blank slate, not to draw from real cities and their histories (as, e.g., Thucydides and to some extent Aristotle).
The first suggestion: a kind of agrarian commune of subsistent farmers.
Objection from Glaucon: this isn't a life fit for men.
The modified suggestion: introduce military, classes, etc. Question (from Popper) of how incipiently totalitarian this is. But (HoPwaG claim) Socrates in fact introduces this as a departure from the (apparent) agrarian ideal.
The picture: guardians, auxiliaries, everyone else (craftsmen). Since important to have the right folks in the right classes, get the other odd features: mating by lot, sharing children, etc etc.
Noble lie introduced as needed to keep class structure stable, keeping people in the right classes. Recall: justice consists in the right classes doing what they ought to. But seem
Recall: wanted justice in soul to reflect that of city.
First claim: soul is composite. Argument: can struggle against itself, so must be composite.
Second claim: soul like city has three aspects
- reason (directed to truth),
- spirit (directed to honor, gives anger and courage),
- appetite (drives for food, etc).
But again we have the pessimistic worry that souls can degenerate, as cities do.
(Just) -- timocratic -- oligarchic -- democratic -- tyrannic.
Versions for both cities and individuals.
Note when the demos in charge, total freedom exists, all desires satisfied and every conception of the good approved. The 'most beautiful' of constitutions, but defective in the ways spelled out: neither reason nor even spirit in charge.
In link between democratic and tyrannical society, again an echo of Athens after the defeat to Sparta.