I feel like I pierced through to some observations about Plato today that may be obvious to other people but which I was pretty pleased with.

So following Whitehead, it's appropriate to think of Plato as a philosopher of Organism.

Specifically, Plato wants explanations to have recourse to actual things that have a self-contained, internally harmonious composition. This is distinctive in comparison to presocratics who accepted explanations with recourse to the tropes or myths of popular speech (neither actual nor self-contained), or to elemental ontologies (these are explanations about emergent character, & so aren't self-contained).

(Note: In this reading, I'm going to ascribe to Plato an understanding of psyche that I've rolled together from my reading of Aristotle's De Anima, but I also think you can eschew this if you don't like it. My reading from Aristotle is of the psyche as the sphere of ultimate recourse of potential, and potential-of-potential, and so on in infinitum.)

SO Plato wants to say that among the presocratics, the Sophists are especially reprehensible, because they view the human psyche as this public thing that can be trans/formed by dialectic. And the problem for Plato is that this is very visibly demonstrated every day in the Assembly and courts of Athens. So Plato needs to respond to this with an account that covers a few bases:
* the role of rhetoric/language as something that shapes the individual and public
* a republic's nested sovereingty