Republic Book 3 Section 1

Plato: "Wet streets cause rain."

"We have agreed, then, that the tales we teach the young will teach them to honor the gods and their parents and to value friendship with one another."

Reality: they can figure this out for themselves. Especially if they see their parents and their parents' peers acting out this honour and seeing the profits thereby. 

By honest error or biological ineptitude, some adults will be less honourable, and the children will see that their friendships are less valuable as a result. No explicit teaching is necessary. Turns out - not that gay men are apt to notice - children have eyes. They can see on their own.

The myths are largely for entertainment. As it happens, they will have elements of honour, but it's largely because the kids like that sort of thing. The children shape the stories, rather than the reverse. 

A myth, or any form of teaching tool, largely works by drawing the child's attention to more relevant details. They learn faster if they skip all the cruft.
Plato, ultimately, is proposing propaganda. Propaganda doesn't work. It directs the child's attention to unimportant cruft, and sooner or later they reject it. In a solidly Sophist regime they won't tell you they've rejected it, but they reject it nonetheless. Propaganda wastes time. Further, if they don't explicitly reject the propaganda, it multiply interferes with learning more. Plato makes you weak.

By contrast, if you tell the children the truth, they can build on that solid foundation. The faster they learn what you know, the more time they have to learn things you don't. An honest society is a knowledgeable society, and knowledge is power. Wisdom is strength.

"Furthermore, we must teach the future Guardians tales that will praise courage and that show fear and cowardice in a bad light."

Personnel is policy. If the lawgivers are honourable and courageous, then these things will be praised regardless of what you teach the "Guardians." If they are not, then injustice will obtain. Cooperation will be disparaged; defectors and their ill-gotten gains will be defended. 

It is a law of nature that lawgivers become corrupt. There's a ratchet: once corrupt they pick corrupt successors and remain corrupt forever. Purity has to win every time, while corruption need only win once. As such, it is necessary to replace your lawgiver. 

The lawgiver himself can't be replaced without contradiction. You can replace the lawgiver if and only if you have already replaced the lawgiver with yourself, and are capable of giving a law of replacement. Regime-complete problem.

Instead, replace your society. Exit the first system of law, in favour of another, headed by a lawgiver who isn't corrupt (yet). By Gnon's mercy, the ability to Exit applies discipline to the lawgiver. For fear of losing their lawtakers, they will mightily resist corruption. The more Exit you have, the more discipline is applied, and the less you need Exit. 

Personnel is policy.
Plato hated children. It's a common symptom of the sodomite disorder.
Platonic institutions are designed to painfully maim any children they come into contact with, to express Plato's hatred.
Public school is pure Plato.

It is clear that public schoolers hate children. I don't know if they saw a kindred spirit in Plato and therefore took his ideas, or, feeling the same hatred and thus the same incentives, derived the same solution as he did. Perhaps Plato is merely used as a buttress. Moldbug believes it was indeed lifted from Plato, but the idea that children/descendants can't think for themselves is itself a suspiciously Platonic idea. On the other hand, you don't have to work very hard to convince me child-haters are mental cripples.

Consciousness is important. In fact there are no material desires; all desires are pure mind. (See also: Hume.) 

Materialists wish you to look away from their non-base desires, so you don't detect their malice. Their envy, their resentment, and their sadism.

Personnel is policy. The body is chosen; the body shapes the mind. The mind is policy. The consciousness you empower determines the results of their actions.