The education will hone these skills to become. The Guardians will be carefully selected from the children of the city who show a natural talent for the skills required for the job.The size must be large enough to be unified but not so large as to be unstable. The size of the state will need to be determined by the Guardians to maximize strength & wealth to the point where it’s most productive (& not yet destructive).Our army may even be able to convince another army either into not fighting us because we don’t have any spoils for them to take home, or into fighting a common enemy by promising them the spoils of the war.The Guardians should be able to handle an army 2x or 3x their size (see the Persian War). But it may be easier to fight such an enemy because it’ll be rich, fat & lazy, & therefore ineffective. A barebones state ordinarily wouldn’t be able to wage war without wealth, especially against a large & rich enemy.Poverty produces meanness, bad workmanship & desire for revolution. Wealth produces luxury, idleness & a desire for novelty.His skills will deteriorate until they’re nonexistent & then he won’t have any work, his children will learn nothing from him & the product or service he provided doesn’t get produced. If a worker is too poor, he won’t have any tools to ply his craft. There are 2 things that can ruin & corrupt the workers: wealth & poverty.

We can’t please one group at the expense of another.

We’re trying to construct a happy community, not happy rulers. They will be happy that the whole community is doing well – that’s where you’ll find the most justice.

The answer was that they only work for their keep.

Furthermore, rulers of other countries are rich & the Guardians may want what they have. They seem more like robotic sentries than actual people. They might be in control of the state but there’s nothing in it for them.

Adeimantus asked if these restrictions wouldn’t make the Guardians unhappy.

Plato the republic book 4