The following text is based on a transcript by V. S. of a lecture  on Plato’s Republic. As usual, I have edited his transcript to remove excessive wordiness and corrected a couple of small mistakes.
Plato writes in his Seventh Letter that he never set forth his own philosophy in any of his writings. That’s a pretty extraordinary statement for one of our greatest philosophers to make. But the question is: If Plato never wrote down his philosophy, then why in the world are we reading these dialogues?
Well, he never wrote it down, but you can infer his philosophy from the dialogues not just by reading what he says, but also by looking at what he does. The dialogues are not doctrines or compendia of doctrines, but they are psychagogical or spiritual dramas.
If you read the dialogues as compendia of positions, you find that Plato seems like a rather extravagant and goofy fellow. Plato believes in communism and in eugenics and in censorship, and things like that. How disreputable. “Thank God we’ve progressed beyond Plato!” Plato becomes an odd sort of footnote, essentially irrelevant to the modern consciousness, because we are all so sure that we’ve progressed beyond him, and he’s a sort of intellectual pygmy compared to anybody who lives today who happens to be in tune with our superior culture. So, any second-rate mind who’s in tune with our modern culture can feel superior to Plato. Frankly, I find this sort of attitude irritating. But you get this with college undergraduates, who patronizingly suggest, “Well, wasn’t Plato just a product of his time?”
Well, yes, but nothing important about anybody is really a product of his time. If Plato were merely a product of his time no one should read him. And insofar as Plato was a product of his time, he fails to be a philosopher, because what is essential about the philosophical ambition is precisely to become untimely, to transcend one’s time and place and make statements that are true universally.
Plato’s dialogues, if read as spiritual or psychagogical exercises, can lead us to an understanding of Plato’s views if we can follow where he’s leading our souls. Because the effect of the Platonic dialogues, the state of mind the dialogues lead us to, is Plato’s real philosophy.
There are four dimensions of Plato’s dialogues that must be taken into account to understand Plato’s teaching: the words, the events, the characters, and the spiritual effect. We don’t fully know Plato’s philosophy by treating the dialogues as mere compendia of arguments and myths. The dialogues are also stories, with characters and events, which the reader must also take into account. Moreover, as the dialogues unfold, the arguments and stories within them have an effect on the characters. The dialogues don’t just change the participants’ thinking. They also reorient their souls. And when the reader grasps the spiritual transformation taking place within the characters in the dialogue, that brings about spiritual changes in the reader as well.
The meaning of Plato’s dialogues cannot be grasped through any of these elements taken in isolation. The meaning is, rather, the total effect of all these aspects of the dialogues on the soul of the reader. Once you put this total effect into words, you have arrived at Plato’s teaching.
So, what would be the best soul for Plato? The best soul for Plato isn’t a soul simply ruled by reason, spirit, or desire. The best soul is ruled by a kind of fusion of rationality and spiritedness. What does that mean?
Spiritedness for Plato is directed towards values or ideals. But in the simplest forms, spiritedness is directed towards values. There are many things that humans can value. Our ability to value is extremely fluid and polymorphous. But the first thing that anybody seems to value is one’s self.
A spirited attachment to the self is not, however, what one would call an instinct for self-preservation. Why is that? Such an instinct would be a desire. Desire is the prompting to maintain life, to gain the necessities of life. You could talk about a life instinct, but spiritedness isn’t a life instinct. A spirited attachment to the self is not an attachment to one’s physical existence. It’s an attachment to the idea of the self. Spirit is an attachment to ideal values, unreal, non-concrete ideal values.
What is the idea of the self? It’s one’s self-image. When one forms an attachment to one’s self-image one can call that one’s sense of honor, one’s self-esteem. But along with this notion of self-esteem comes the concept of honor.
The clearest example of this is when someone treats you in a way that doesn’t fundamentally accord with your image of yourself. What happens when somebody does that to you? If you think well of yourself, and somebody cuts you off in traffic or barges in front of you at a movie theater or pushes you aside with his overladen basket in the grocery store, what’s the reaction that you have? Anger. You feel dishonored, disrespected, and you get angry. So, anger is always connected with the spirited part of the soul. It gets angry over ideals that are not properly respected, including the ideal of one’s self.
The trouble with spiritedness is that it’s a somewhat undiscerning capacity to value. So, for instance, even murderers and psychopaths have a certain attachment to themselves, a certain fondness for their selves that goes over and above their self-preservation instincts. You also form spirited attachments to things that are close to you like your family and your friends.
What we call sentimental attachments are spirited attachments because they are affixed to things that are intimately connected with and almost definitive of one’s identity. So, there’s a broadened sphere of the self. One gets upset when somebody attacks a member of one’s family. If somebody disrespects your sister, you get angry over that. If somebody says “Your momma wears army boots,” you might want to knife them.
But sadly some families are just packs of wolves. Some people would be better off being raised by wolves than by their own parents. And yet people still form attachments to them. Or attachments to one’s hometown. Or one’s native tongue. Or one’s homeland. Spiritedness forms attachments that are somewhat undiscriminating as to the true and proper things that one really ought to value.
When writers like Adam Smith talk about moral sentiments, they are really referring to is this part of the soul. Let’s not treat it as mere sentiment, though, because there are some sentiments that are good. When you talk about sentimental attachments you are talking about attachments to things that are familiar and old. These things are very much caught up with your sense of self, your personal history. But sentimentality can easily take on a negative, dark quality because is often connected to a false sense of innocence, including one’s own innocence.
But, on the other hand, the last thing you want is a human being who is not fundamentally oriented towards values—values over and above creature comforts and self-preservation. Human beings can be turned into very mean animals by devoting themselves to creature comforts and self-preservation. People can be enslaved by their desires.
The lack of values is nihilism. The rule of pure reason in the soul is in danger of becoming nihilistic. A concern simply with facts, with the logical, with the mathematical, with the rigorous, leads to scientists who say, “This is just a morally neutral activity. We’re just hired brains, and we’ll work for anybody. We’re not concerned with ethics. We’re concerned with simply getting to the facts.” This morally cowardly or nihilistic attitude has been transformed into a kind of moralistic mission, a high calling and purpose, a kind of religion of science.
The possibility of a Mr. Spock strikes me as deeply disturbing. Since pure reason—reason understood as a mere calculative faculty—doesn’t give rise to values, but people still have to act, the Mr. Spocks end up being ruled, oftentimes, by their basest desires. There’s an alliance between amoral, scientific rationalism and hedonism.
Here, again, I will lapse into Star Trek. Just think of Mr. Spock. What makes Mr. Spock tick? It’s kind of hard to understand what motivates him. Being in a ship that explores the cosmos and collects facts is the perfect place for a Vulcan. But every seven years Mr. Spock goes insane and runs amok when his desires take over. He oscillates between a distracted scientific rationalism and an unhinged hedonism.
Another example of this from pop culture is an episode of The X-Files that I call “The Robot Cockroaches from Outer Space” episode, because I forget the episode’s real name.  In one scene a sexy female entomologist, a bug scientist, is talking to Fox Mulder in a darkened lab at night. She says, “I admire insects. They don’t have any pretensions. They just eat and sleep and breed, and that’s it.” At that point, you expect the two of them to tear one another’s clothes off. Because that’s what it’s leading up to.
Here again we have a scientific mind that sees values as essentially subjective and arbitrary and thus unworthy of any respect, teamed up with a kind of hedonism that thinks that animals are superior because they lack morality and self-consciousness. Human beings have this strange tendency to erect systems of values that tamp down on purely physical impulses like sex. Cockroaches don’t write love sonnets or commit suicide over broken hearts. They just reproduce and die in a sort of blissful unconsciousness. Wouldn’t we all be better off if we were that way?
We live in a culture where there’s a tag-team routine between pure science, which sees through values and creates an atmosphere of cynicism, and a carnivalesque, hedonistic popular culture that’s all too happy to have all these pretenses torn away, because after all these things get in the way of our satisfaction.
There’s something deeply disturbing about a mind that’s ruled by pure reason, because pure reason needs to be ruled itself. It needs to be ruled by an orientation towards what is good. Nothing we excogitate is unconditionally good. There are all sorts of ideas and inventions that maybe shouldn’t exist, if we think in terms of oughts, of what is good. The activity of reasoning itself needs to be governed by an orientation towards the good, towards values.
The Platonic view is something like this: The mind that is ruled by an orientation towards ideals, bereft of reason, could be swept up by irrational enthusiasm. But at least it’s idealistic. At least it’s open to the good, however mistaken it might be about it. Whereas the mind that is exclusively rational without a value orientation is capable of seeing through the difference between truth and falsehood, but it has no values to guide its activities. So one needs a kind of fusion of value orientation with rationality. One needs, in short, knowledge of the good. One needs an orientation of the rational soul towards the good and by the good.
The whole reproductive regime of the Republic is a picture of a world where human attachment is annihilated except for attachment to the city. It’s an inhuman and unrecognizable world, based on the rule of a pure functional rationality that insists that human beings have one aim, which is to perform their function in society, and everything that competes with that aim has to be eliminated in the name of mechanical perfection. Thus natural human love of one’s own, our preferences for things other than society as a whole—our families, our friends—must be uprooted. It’s a kind of engineering mentality. There’s something insane about that. Especially when you apply it to human beings.
The proposal about sexual equality is made in total abstraction from the body. We’re talking about putting women in the military, and the first thing that Socrates proposes is that physical differences are absolutely irrelevant. Only mental faculties should be taken into account. What a preposterous notion! We’re talking about soldiers and the police. Why would one abstract away from the body? Well, if one has a kind of autistic bloodless logicality, these aren’t differences that make any difference.
Then there’s the discussion of wives and children in common and community of property: the communist proposals. Again, these illustrate the impropriety of abstracting away from natural human partiality. Such partialities are just part of human nature. They could be good or bad, but they can’t be gone. All of these weird proposals are there precisely to illustrate the limits of a kind of bloodless rationality in ruling over of life.
These proposals are not Plato’s actual policy prescriptions, and he knows they are problematic if taken as such. They are instead offered as psychagogical exercises to help Glaucon. However, I wish to argue that reading the Republic as a psychagogical exercise still points to Plato’s true model of the best regime.
You find this claim in Socrates: To know what’s good is to do it. If you know what is right, and if there are no forces preventing you from acting on it, then you do it. Virtue is a kind of knowledge of the good. With virtue, it’s possible to bring knowing—rationality—together with the good. It’s possible to educate our sentiments, to educate our spiritedness, to imbue it with the capacity to distinguish between truth and falsehood in the realm of values. This is at the core of what Platonic philosophy is about.
The best kind of soul, therefore, is a soul that is primarily oriented towards values, but is purified by and educated by reason in such a way that it becomes discriminating between true and false values. It represents a kind of fusion of rationality and spiritedness.
But the ruling principle seems to be spiritedness. Spiritedness is the final ruling factor for the simple fact that reason has to be ruled by values. Yet, at the same time, your value orientation needs to be informed by reason, to be educated by reason, to be made subtle by reason, and to have its illusions purged away.
Now, let’s ask what kind of city would be analogous to that ordering of the soul. It would be a city ruled by spirited types, but these spirited types would be liberally educated. They would be educated by philosophers to be discerning about issues of truth and falsehood. It would be a city ruled by gentlemen, gentlemen who go to school and get liberal educations from philosophers.
Now let’s stand back and look at the whole drama of the Republic: That is exactly what we see. We see an ambitious young gentleman being educated by an older philosopher. The best kind of regime is not the rule of philosophers, nor the rule of mere spirited barbarians, but the rule of spirited men who are educated by philosophers.
The concept of spiritedness, thumos, first appears and is developed in Books II, III and IV. Thumos is located in the chest. In the Timaeus, Plato associates the three parts of the soul with three parts of the body. There’s reason which is in the head, spiritedness which is located in the chest where the heart and lungs are, and desire which is located in the belly.
Why is thumos associated with the chest? Because when you get angry your heart beats. When you hear stirring music, like a national anthem, you feel it in your chest. So, there’s actually a physiological meaningfulness to locating this capacity to value in the heart and lungs.
It turns out that whenever Glaucon is described he is characterized as being spirited. Glaucon is described as erotic, musical, and spirited, and when these topics come up, Glaucon is the one who discusses them.
The musical dimension of Glaucon is what makes him susceptible to liberal education, because as it turns out music refers to all the liberal arts, all of the things having to do with the muses. So, the best regime is a society where you have gentlemen who are educated in the liberal arts by the philosophers, but the philosophers don’t rule.
Alfarabi was a Medieval Arabic philosopher. This is Leo Strauss on Alfarabi’s commentary on Plato:
We may say that Alfarabi’s Plato eventually replaces the philosopher-king who rules openly in the virtuous city by the secret kingship of the philosopher, who being a perfect man precisely because he is an investigator, lives privately as a member of an imperfect society which he tries to humanize within the limits of the possible. 
The philosopher is a person who strives for spiritual perfection in the midst of a society that he doesn’t expect to become perfect, but he seeks to humanize that society as much as possible. How? Ultimately, by educating its rulers.
The Republic tries to make clear that the analogy between the city and the soul is extremely useful, but that it ultimately breaks down when you talk about philosophy, because there can be no city that’s analogous to the philosophical soul. There’s a kind of incommensurability of the interests of philosophy and the city. There’s never going to be a complete harmony between the interests of philosophy and the interests of society.
Why is that? There are two important reasons.
First, for Plato, every society is ultimately partial, parochial. Even the best societies are going to have an Us or Them quality to them, whereas philosophy can’t be limited by those kinds of considerations. Philosophy is cosmopolitan.
Second, every society needs to make some opinions authoritative. Every society has to have basic, unquestioned presuppositions that the average functioning citizen simply believes in if the society is going to work. But philosophy can’t have any unquestioned presuppositions. You can’t let certain things go undiscussed. So, the interests of political stability are always going to be inimical to the interests of philosophical investigation.
One of the things that the Republic tries to teach is precisely this disanalogy, the fact that there will never be a society analogous to the soul of the philosopher, and that philosophers will always, therefore, have to live in imperfect cities. But if you look at what Socrates does in the Republic, he’s trying to improve that imperfect city by educating the minds of its ruling class.
  I hate The X-Files because of the combination of cynicism and credulity that it tries to spread through our culture. It’s also boring and farcical. The characters never grow. After seven years of seeing aliens and all manner of vampires, Scully just couldn’t be the same sceptic that she was at the beginning.
  Leo Strauss, Introduction to Persecution and the Art of Writing (Chicago: University of Chicago Press, 1952), p. 17; cf. “Farabi’s Plato,” Louis Ginzberg Jubilee Volume (New York: American Academy for Jewish Research, 1945), p. 384.