The Republic is Plato’s most famous work. It focuses on a crucial ethical question: is justice good in itself, or is the fear of retribution our only reason to be just? The question is examined through a conversation between Plato’s teacher, Socrates, and a number of other characters, including Plato’s brother Glaucon. Glaucon uses the story of Gyges to put the question in its starkest terms: if you had the opportunity to grab wealth and power at everyone else’s expense, without any chance of retribution, what reason could there be to pass it up?
The Republic, like most of Plato’s works, is written as a dialogue. This is not simply a matter of literary style - it goes to the heart of Plato’s views about the practice of philosophy. You cannot obtain philosophical knowledge, Plato thought, by accepting the pronouncements of expert philosophers. You need to do philosophy - to engage in debate, examining the questions, looking for objections, and puzzling things out for yourself. The role of the teacher is not to impart knowledge, but to help the student to generate and criticise his or her own ideas. This conception of education has been crucial in the philosophy of education and in the teaching of philosophy since Plato’s time.
The Republic, admittedly, is not the best example of this - the speeches are long and Socrates is allowed to present his views almost unchallenged. But Plato certainly does not intend his readers to turn off their critical faculties, but to engage with Socrates’ arguments in a spirit of joint inquiry.
Perhaps the most astounding feature of The Republic is the range of issues that it covers. Socrates begins with an ethical question, but his discussion ranges over politics, knowledge, the nature of reality, education, mathematics, art and psychology. But the dialogue is not a hotchpotch of loosely related topics - Socrates has a clear conception of how these issues intermesh. In particular, he argues, we cannot understand the value of justice - personal or political - unless we understand what goodness is in reality, and how we come to know it.
So how does Socrates’ answer Glaucon’s question? He begins with an account of the soul. The soul, he suggests, contains three elements: desire (desire for food, sex and so on); spirit (in the sense of spiritedness or feistiness); and reason. In the healthy soul, reason will rule desire, with the assistance of spirit. Someone who has a healthy soul will be just inside and out: just on the inside, because it is right that reason should rule; and just on the outside, because someone who is ruled by reason will not be the sort of person to rob and cheat. Finally, Socrates suggests, we should want to have a healthy soul, just as we want to have a healthy body. We would not want to be like Gyges - a chaotic individual, ruled by his desires.
Is it true that someone who is ruled by reason will act justly towards others? We can easily imagine a rational villain. But Socrates has an answer to this objection. According to Socrates, the rational part of the soul loves truth; it aims at, above all, knowledge of the good. The person who is ruled by reason will be a philosopher who seeks knowledge of the good. Socrates also assumes that to know the good is to prize it. So the philosopher will understand how to act well and justly, and will wish to do so.
What does this imply about trust? Not much, it seems. We can trust the philosopher not to rob or cheat. But not many people are philosophers in Socrates’ sense. For security, we will still have to rely on laws, and that presupposes a political system.
In The Republic, Socrates offers an account of the just state, alongside his account of the just soul. Whether the account of the state is intended as a piece of political philosophy or only as an analogy for the soul is highly controversial. But it has certainly been interpreted as a blueprint for utopia by other thinkers.
Socrates suggests that the state, like the soul, can be divided into three: the philosophers, who represent reason; the auxiliaries or soldiers, who represent spirit, and the artisans, traders and farmers, who represent desire. The just state is ruled by the philosophers, with the auxiliaries in support. The result is a deeply authoritarian state, in which only the philosophers have a say in government. This is justified, Socrates argues, because it is only the philosophers that care impartially for everyone and know what is for the best. Only the philosophers can deliver the security that the ordinary citizens need to pursue their individual interests.
Plato’s ideal state is founded on trust; but it is a trust that runs only one-way. The questioning, challenging attitude of the philosophers is not required of the ordinary citizens: they are expected to trust their rulers without question. Indeed, Socrates suggests that the rulers would be justified in lying to the other citizens, provided that this is for the good of all. The trust that Socrates asks of the ordinary citizens seems more like the trust of a child for its parents than the mutual reliance of adults.
Plato does not ask us to accept this vision - he presents it to us as philosophers to question and to challenge. And indeed it raises some unsettling questions. Many find Plato’s just state deeply unattractive - they resist the idea that we should be ruled by people who know what is best for us. But if we could choose between a democratic system, which might produce as many bad decisions as good ones, and rule by experts who are guaranteed to make the right decisions, would it be rational to chose democracy? Would anything of real importance be lost to us in Plato’s ideal state?