The E.B. macro article on metaphysics says that the earliest of the Greek philosophers asked the question, "Ti to on?" What is existant? A new twist was given by Pythagoras who said that it was no material substance but structure, numerical structure. This is the origin of Plato's theory of Forms (eide), which are intelligible structure and not material. The doctrine of Heraclitus of flux made Plato assert that the world we see never is; everything is always coming into existence and passing away. The Form world is ordered through and through by the ultimate Form of Forms, the Good (which to the Neo-Platonist was the One, although Plato probably did not mean what they meant). Plato did not mean to deny existence to the world of flux; in Timaeus he presents the Demiurge (by which term he means God) copying the Forms to produce the sensible world out of space (which was the receptacle of being).
What impresses me in this account is:
1) Plato's theory of Forms arises from Pythagoras' view that the ultimate substance (substantia) is not material but is intelligible structure. This fits with what I saw.
2) Plato faced the fact of Heraclitus' flux world, and Plato brought forth the theory of Forms as a contradistinction to this flux world. This again is precisely what I saw.
3) There is this Form of Forms, the Good, which orders the Form world through and through. Therefore it is evident that the Form world, if apprehended by the intellect (of a man acting as percipient) would most likely be a kosmos such as Pythagoras describes. It would be a structure of structures, so to speak: a meta-structure that is intelligible, not material, not in space or time, and standing in opposition to the flux world in one sense and yet in another sense involved with the flux world as archetype to copy (Form world as archetype, flux world as copy).
The only place where my vision differs is that I saw the flux world feeding into the Form world (Valis' soma, the meta-kosmos) to further the development of reticulation and arborization. This may be the double emanation of Plotinus, from higher to lower to higher.