Mary Renault was a great writer who set her novels mainly in ancient Greece. I think her best work was the retelling of the Theseus cycle of legends, in The King Must Die and The Bull From the Sea, but The Mask of Apollo was also very nicely done.
The narrator is Nikeratos, an actor, in the 4th century BC. By chance he meets Dion, closely related to Dionysios the tyrant of Sicily, and through him Plato. Nikeratos is impressed by both, but especially by Dion, and is uncertain why. He has to think about the matter for awhile.
The novel is set at a time when Plato has gotten old, after Athens had reached a height of culture and power unprecendented in Greece, and then had thrown it away in the Peloponessian War. Humiliation had followed in Athens (Nikeratos is Athenian, as is Plato), the Spartans had briefly been the dominant military power in Greece until thrown down from that position by Thebes, and the 4th century is one looking backward at past glories, and wishing for them to come again. Nikeratos diagnoses his attraction to Dion as the wish for a king to lead Greece back to glory, a feeling that many others felt.
His acquaintence with Dion brings him the lead role that the tyrant Dionysios has written (writing plays was Dionysios’ hobby, one that he got pretty good at), and helps bring it first prize at a festival in Athens. When Dionysios learns of this, he throws a party, is stricken with a fever, and dies. His son, whom he has never allowed to learn anything about being a ruler, inherits, though Dion is far better qualified, being a military man and quite incorruptible. Dion’s friendship with Plato has introduced him to philosophy, and made him an even better man.
With Dionysios’ death there’s an opportunity for Plato to attempt to create the ideal city he wrote about in The Republic. Plato felt that only a philosopher king could hope to lead a city to virtue. The problem was to find a king willing to study and practice philosophy. Most powerful people are not interested.
The second Dionysios, on inheriting power, is mostly interested in using it for pleasure. He has little character, but is interested in Plato, a powerful personality who impresses him mightily. Becoming familiar with Plato’s writings, he sees the figure of Alcibiades, the brilliant and rash young man who becomes close to Plato, but doesn’t become a philosopher, and ends having squandered his talents. Dionysios sees himself as another Alcibiades (though by no means as handsome or intelligent) and yearns for the reputation of Plato’s best disciple–without having to work for it. Plato is willing to take many pains to try to persuade him, but it doesn’t work. Dionysios is jealous, and easily led by others hostile to Plato. Eventually, out of jealousy, he exiles Dion, sells his properties, and declares Dion’s wife (whom he has had to leave in Sicily) divorced, and marries her to a friend. Dion now has reason to overthrow Dionysios.
He does so, and is welcomed deliriously by the citizens of Syracuse, but having lived under a tyranny for 40 years, these have little judgment in politics. A demagogue manages to persuade them that Dion is a traitor, and they throw him out again. Eventually Dion does attain supreme power in Syracuse and the rest of Greek Sicily (part of the island is occupied by Carthaginians), but has shown that he doesn’t have the fiber to be a successful ruler.
The demagogue who had had him ousted is tried for treason (he was power-hungry, but incompetent), but Dion asks the Syracusans to forgive him. Restored to freedom, he continues with the same tricks, and Dion allows someone to murder him. The forgiveness was compatible with philosophic principles; the murder was not.
In the end Dion is assassinated by someone he trusts, who thinks he’s become a tyrant. From there Syracuse descends into chaos. The citizens, having lived so long under tyranny, are irresponsible, willing to follow any demagogue anywhere. There are repeated coups, trade and population decline, and don’t revive for quite some time. If Plato’s prescriptions were to work, one suspects that he needed a higher-quality citizenry to work with.
Meanwhile, Nikeratos is back at work as an actor, after having witnessed much of what had happened in Sicily. He is beginning to get old, but happens to meet the young Alexander, before he became the Great. He sees someone with perhaps as much intelligence as Dion had had, but with less philosophic background, though Aristotle is his tutor. Aristotle was somewhat less than interested in Plato’s view on government.
Nikeratos also sees in Alexander a young man hungry for honorable achievement, and doubts that he can find the food he needs for that aspect of his ambition in the world of that day. In hindsight we can admire Alexander’s leadership skills, his attempts to get Greeks and Asians to live together amicably (though not extremely successful), but wonder at his mourning that he had nothing left to conquer. Had he been more of a ruler, and perhaps less of a military man, he might have been an earlier Augustus, who administered an immense empire that had been torn by civil war, and made it rich and peaceful again.
The Greeks got the king they were looking for, but how much of what Alexander accomplished worth accomplishing? There will probably be as many answers to that question as points of view. It does seem that Renault is right in saying that humans periodically want kings. Charisma is exciting, but what makes a really good king often is not. She has Nikeratos encapsulate this in commenting on how much wisdom the philosophers had, but that they didn’t know a crowd.