I think you know the following quotation:
"All truths are "half" truths".
In my opinion this is heavily influenced from the "Pro-Socrates" state of mind, and there is a conversation of Protagoras (Sophistes) with Socrates, that the first tries to convince the second about the relativity of the "truth".
Can we discuss the statement of Kybalion, "While the Universe is not, Still it is", in the light of the above relativity of the truth? Would you also relate this, with the following:
"Nothing can exist outside the "whole".
You perceived and understand it completely different from me, but it's completely fine.
You maybe explained the "while the universe is not" with the part of our mind, that out of lack of knowledge, or "ignorance" is impossible to know all the mystery, but it doesn't mean that the mysteries, and the things we are ignoring, are not there. It is very interesting interpretation Kristian murray flory.
I perceive it though, completely different.
My perception on the matter is like the Cave of Plato: There is the idea of glass, and the glass. The idea of glass in the 3dimensional reality is very abstract (is not basically), however there is a glass in the 3dimensional reality.
What I try to perceive and acknowledge with this "key" the Kybalion is giving us, is that we may treat the 'universe' as real, but in the same time not forget that is the projection of our mind that we see, and this is subjective.. however im not sure if it's unreal..
It is a 'two-fold' law, like duality you are nicely describing.
You don't need to be scholar to have opinion :)
"All is in The Mind" - But Earth is real while you are on it as a human being. You can get hurt if you smash into a brick wall.
Who you are might vary your experiences not excluding lessons you should learn.
We exist purely in duality. Only the universe can know Unity. All manifestation, in all ways, even the comprehension of, especially the comprehension of it is founded in duality. Light cannot exist without a frame of reference, Nothing can. It is all Mind. The Kaballah is founded of this. The letter Q represents this. The trinities evolve from this.
In Not Being, it is still. Even in stillness it is Not.