Are you ever going to get around to your proof of that btw?
I will try to provide one.
Evidence that there is one Truth using minimalist criteria.
The Idea that all things come from one thing was posited by both Vedantic seers and Thales of Greece. Current science suggests this is correct in the following way:-
Every process in our universe is an effect of a singular event, the Big Bang and hence are fully united as effects of one over-arching causal event. The event space of the universe could have been independent worldlines, but they are not. They are all convergent in the past.
Every matter in the universe are various manifestations of one matter. This has not been shown yet, but string theory and other QG theories are formulated in such forms. Similarly all force from one force.
Thus its highly likely that the apparent diversification of phenomena is an apparent diversity of groups and forms rather than of fundamental entity or force. This supports the fundamental postulate that "there is only one thing that has become many things through diversification of groups and forms"
Finally we (and other beings like animals, gods etc.) are perceiving this world by our awareness. Thus awareness has two aspects
1)Awareness of the world. This changes all the time and also between people. But if the earlier analysis is correct, this diversity is that of modes and not essence. So essentially all of us are perceiving the one thing in its various modes (blind men and elephant)
2) Reflexive self awareness. The feature of awareness that loops back on itself so that it knows that it is aware. While the content of awareness changes, all awareness contains this constant self-aware aspect that is contiguous over a series of awareness events hence serving as a glue to hold them together. While many features of this self changes with content of consciousness, it's self-aware aspect remains constant. But, removing the changing content, the self_luminous nature of awareness is an invariant feature of all aware beings.
3)So we have an invariant self sense coupled with an awareness of various phenomenon, which, even though they look different, are actually emergent of same material and causal unity. These two things are called Purusha and Prakriti respectively.
4) Now the final postulate is that the identity rule that keep the self sense (atman) invariant under all awareness events is the same identity rule (Brahman) that keeps the essence of the world invariant through all causal processes in the outside world. Through it all X==X is maintained for both by the same identity rule. Thus the self in the world is the same self in consciousness. Atman==Brahman
