This can be its own thread - I'm actually surprised there isn't one already.
As there isn't a pertinent thread, beyond the discussion Wilshire already linked, I thought I'd drag a couple other pieces of speculation - not necessarily stuff I agree with but Thorsten offers a valid stab.
Thorsten's Metaphysics of Earwa - Pre-TJE
The Chorae
The Trinkets fall rather nicely into this concept. If sorcery is a Onefold Thought where an insinuation of more in the perceived reality is turned into perceived reality by creating absolute meaning, the Chorae would prevent this by removing the insinuations of more. That is precisely why they are felt by a sorcerer as an absence in the onta (DB, Ch.1). The name is presumably derived from
χωρη - proper place
and this is literally what the Trinkets do - they locally force true reality to be in its 'proper place', i.e. to equal perceived reality. In other words, they destroy reality in order to reinforce an illusion of perception. Small wonder a sorcery based on contradiction like the Aporos was necessary for their creation!
Interestingly enough, it seems the Chorae must touch skin to offer protection from sorcery (WP, Ch.18). The question remains as to why Chorae destroy sorcerers as soon as they have actually used sorcery. It seems in most cases sorcerers touched by a Chorae turn to salt (e.g. TT, Ch. 16), but in some cases, cf. the end of Moënghus, this does not seem to happen. Partially, the explanation may be that Chorae are needed by RSB as a device for the story - without their threat, given the power of sorcery, there would be no need for conventional warfare with armies. It is chiefly the threat of Chorae bowmen which prevents sorcery from becoming the chief means of warfare, so this property of the Chorae is rather needed.
But (leaving aside the salt as a nice dramatic touch) it would also fit into the pattern outlined here. A sorcerer using sorcery leans out of the reality perceived by other people by creating absolute meaning. This other reality (created by the super-consciousness of the Thousandfold Thought) adjusts and is forced locally to agree with the sorcerer's reality. But this adjustment may not be perfect, so in a sense a sorcerer after using sorcery never quite remains in the same reality as other people. Given that true reality is sufficiently indefinite, that doesn't matter. The Chorae however force true reality to agree with perceived reality and hence leave no place for the slightly different reality of the sorcerer, therefore destroying him.
There are also mentions of 'anarcane ground' (TT, Gl. 'Arithau') in the text on which renders sorcery impotent. This may or may not fall into the ideas developed here, there's simply not enough information to judge how anarcane ground works.
Thorsten's Metaphysics of Earwa II - Post-TJE
The Judging Eye
The strongest evidence that Kellhus does in fact not represent the God is given by what Mimara's Judging Eye sees in Achamian. Supposedly the Judging Eye should show an objective moral judgement (we have at present no way of really knowing if that is the case, but I'm willing to accept the idea for the moment). Since Kellhus claimed he can rewrite the holy texts and in doing so save the sorcerers from damnation, but Mimara continues do see the damnation of sorcerers, it would follow that Kellhus' claim is wrong. And if Kellhus' claims to spiritual matters are wrong, he cannot be a prophet or represent the God. This would make him appear as someone who poses as a prophet to make use of the belief of others for his own ends - just what he started out to do back in DB.
The truly interesting question is - what does Mimara see when she looks at Kellhus with the Judging Eye? If he is a prophet who just happens to be using the Gnosis, then he may not be damned, but if he is a sorcerer who would like to appear as a prophet, then the Judging Eye would show him as damned just like other sorcerers. Unfortunately, we don't know (although it's a bit of a stretch that Mimara who spent time close to Kellhus wouldn't know and Achamian wouldn't ask her).
In the terminology developed before, what actually is the Judging Eye? It would be something like the ability to see the world while tapping the super-consciousness that is the God, i.e. to see more than one's own judgement, but rather a collective judgement.
The Chorae
Previously I argued that Chorea 'force true reality to be in its 'proper place', i.e. to equal perceived reality [i.e. the God]' and that they can therefore be used to 'anchor' something in reality (in fact, I argued that this is their function for the No-God). This idea is confirmed rather nicely in JE.
At the beginning of the key scene in Ch. 16 Mimara observes how reality seems to move whereas the Chorae remains steady: 'a sense that it is not theTrinket that moves so much as it is the whole of creation about it'. Later she uses the Judging Eye to see 'through' the Chorae, and she finds a light, a 'point of luminous white certainty' which she sees as a Tear of God. That is precisely what one would expect to happen in my theory of Chorae. The Judging Eye shows the objective moral judgement of something. The God is emergent from reality perceiving itself in the minds of people. The Chorae forces true reality to be perceived reality, i.e. it shapes the reality of the God out of chaos - of course that act is identical to the nature of the God, and that is what the Judging Eye perceives. This, in fact, is my main argument why the explanation of what the Judging Eye is is correct - it agrees with everything we can deduce about Chorae.
Achamian is astonished at what Mimara does with the Chorae - he is of the opinion that Hell should have swallowed them whole, Chorae or not. But I don't think that could happen - a Topos, the Outside, should be no more able to swallow a Chorae as a sorcerer should be able to use it. Thus, my conclusion is that Achamian is in error here. After all - how could he know?
I think we simply don't know enough, Deliverator.
A friend of mine and I tried to narrow it down to a specific linguistic statement: Anyone looking at
any Chorae
with the Judging Eye would see what Mimara saw.
Does that reflect aspects of Aporetic sorcery? Aporos is only historically considered a forbidden branch of sorcery among the Nonmen because of their Quyan Civil Wars before the Fall of the Ark.
Is the Judging Eye actually the perception of righteous Judgment in Earwa?
Do Mimara's
words about
guarding the Gates actually make the difference and persuade the Wight, rather than the obvious Chorae/Judging Eye phenomenon?