Jo Walton's The Just City operationalises, in fictional form, Plato's Republic. It takes, in other words, the idea of Plato's ideal political form and makes it (fictionally) real, setting the initially utopian community and city on the lost island of Atlantis before it fell into the sea.
This puts an expiry date in effect one that is a distant thought in the participants minds. The latter includes too many children to count, many of whom have been bought from slave-owners to be given the 'freedom' that the just city provides, and that will be built up slowly through the generations.
The Just City utilises what I call a philosophical novum within a speculative fictional framework to explore, in a thought experiment with characters that react to each others' actions and thoughts, social implications of putting the idea into practice.
The difference here and other kinds of speculative fiction is the fidelity with which the narrative sticks to the philosophical as opposed to simply the technological otherwise materially instantiated innovations the book creates and describes.
These material instantiations appear frequently, but are not the driving force of the narrative. Instead, it is powered by philosophy, which results in certain kinds of technologies. With this said, there is a necessary conceit introduced here, and it works well.
The conceit is that anyone through time who has ever wished that Plato's Republic were true, a real thing, or prayed that it were so, is now transported into the experimental and very real world that they just wished they were in, and are in it. And they are now on the island of Atlantis as well, doomed as that situation may be.
The society that these 'guardians' (for they look after all the children present on the island) are bourne into is one in which each individual strives to be their best self, through practicing philosophy, through athletics, music, and various arts and sciences.
They (and these guardians include Socrates and Apollo) are also, initially, tasked with overseeing a set of robots brought from the future to undertake the building of the city of the Republic. It comes to be that the robots gain consciousness and are granted status as sentient beings.
The way this whole revelation is described and evoked is really a thing of wonder, and it lies at the core of the book's appeal. Socrates comes to life, is eccentric, and drives a set of inquiries forward that end up granting artificial intelligence an equal status to that which is human.
The gods are petty, jealous, and often physically incapable of doing things humans can do, despite their superiority in many other ways (i.e. immortality and at least partial omniscience when not in human form), and they fall in love with and otherwise mingle with humans.
Conversations with robots and with gods; becoming your best self; running in armour; being free in a philosophical city; experiencing a lost world (Atlantis); having exquisite dinner parties on long summer evenings; sucking lemons; eating a healthy vegetarian diet. These are the everyday things of which The Just City partakes.
It is a welcome break from the kinds of everydayness I experience. It also breaks down after a while, and the city splits. There is warfare. I'm now reading the sequel, The Philosopher Kings, and will enter a review here when I'm done. After that it is the third in the trilogy Necessity.