I think what we are getting at here is the non-dual perspective, which does indeed seem to be the highest and most inclusive perspective that we have found, and it does actually solve the body/mind duality rather elegantly.
The most modern version of it that can be taught rationally (I would classify non-duality as trans-rational) would probably be integral holism. The basis of that is basically as follows (very, very simplified obviously):
EVERYTHING can be viewed as a “holon”.
A holon is simultaneously a whole and a part. Thus we avoid the pitfall of atomism (everything is just “stuff”, gross reductionism) and system theory (everything is just systems or wholes, subtle reductionism). An atom is (or can be) part of a molecule (while still being an atom) and is itself made up by sub-atomic parts. Every new level of the hierarchy adds novelty, meaning that molecules can do things that atoms can’t, and cells can do things that molecules can’t etc etc. This solved the modernist problem of “flatland” where everything is reduced to either/or. According to this perspective it’s both/and.
The other problem that needs to be solved is the post-modern issue of relativism, which basically ends up saying that since there are endless perspectives and contexts available, they are all equally valid. According to integral holism that is solved since something lower in the hierarchy is more fundamental (you need the lower levels in order to get the higher but not vice versa, we can have molecules without cells but not cells without molecules, hence cells are “higher”), and higher levels are more significant (or valuable). This way you get qualitative value as well as quantative. Matter is more fundamental than life, and has a bigger span (there is more of it), but life has more depth/height because it contains (and transcends) matter, and such has more qualities. Everything that matter can do, life can do, because matter is a part of life (all life has matter) but life is not a part of matter (you can take away all life in the universe and it would not influence matter at all).
This way you basically get three realms that build on each other but that also transcend each other. The physiosphere enables the biosphere that enables the noosphere. This hierarchy is clearly not arbitrary and gives us the ability to assign both span and depth, or quality and quantity, in a logical way that is backed up by both subjective experience and objective verification. It also becomes very obvious that the separation between spheres are vital. Biological life can not be reduced to matter because it has completely new properties. Physics does not explain biological behavior. And the mental realm can not be reduced to the biological, since thoughts, ideas and concepts can not be explained by neither physics not biology.
The problem for rationalists is that this is as far as they can go, and it still leaves us with the mind/body problem. How does the nonphysical mind interact with the physical? The non-dual sages clearly say that it is not possible for the rational mind to understand it, you have to develop your mind to a higher level in order to see it. Basically the psychological term for “rational mind” is “formal operational”, which is pretty much as high as “normal” people develop today in civilized countries. The collective evolution of formal operational cognitive functions was the evolutionary perquisite for western enlightenment, and became the celebrated goal, which is great. It’s a much better operating system than the mythical “concrete operational” that precedes it. But in order to fully understand the nature of the Kosmos, the sages say, you have to go one step further into what is today called “vision logic” or “network logic”. Then you need to use this new cognitive ability to investigate consciousness itself.
What they are getting at here is the basic subject/object split. There is an awareness/consciousness in you that is not an object, in fact it can not be experienced at all because it is what is experiencing. The sages basically instructs us to turn our attention inwards in an attempt to first identify the subject/object split (to firmly understand that you are not what you are experiencing, you are the awareness/consciousness where the experience is happening). Then by resting with full focus in that awareness, ignoring all distractions (i.e. objects/experiences) awareness will finally become fully aware of itself and reveal it’s true nature. This true nature is then described usually by words like “emptiness/source” and breaks the dualist spell. As Buddha puts it in the Heart Sutra “Form is exactly emptiness, emptiness is exactly form”.
Or as Ramana Maharshi puts it:
The world is illusory
Only Brahman is real
The world is Brahman
Or as some Zen monk put it:
Still pond
A frog jumps in
Plop!
What is supremely interesting is that all the non-dual sages say exactly the same thing, but with different cultural context. The Buddha, Ramana Maharshi, Nisargadatta Maharaj from the East, Plato, Plotinus and Meister Eckhardt in the West, and Jesus in the middle. Everyone say the same thing. The world only appears dual (mind/body) but is essentially non-dual, and the key to understanding this is consciousness itself.
But since actually realizing the truth of this takes both a very high level of cognitive development (beyond rational) and specific methods (forms of meditation essentially) it is in reality not available to everyone, though in theory it is available to most people today. Today the main problem stopping people from realizing this is the confusion between pre-rational (conop) and trans-rational (vision logic). Basically the enlightenment in the West decided that everything that was not rational was pre-rational, throwing out the spiritual baby with the religious/mythic bathwater. The western enlightenment also created a “flat world” only consisting of matter, basically stating that everything is an object (or physical system) and consciousness is just an illusion or byproduct, or the “clockwork universe”. Then post-modernism comes along and says no, everything is subjective, which gets us out of materialism but still doesn’t solve the problem. The next step is integral holism which finally manages to unite the two, but you essentially need to enter the realm of the “mystical” in order to get the final answer. Which many rationalists don’t like because they confuse words like “spirit” or “mystical” in this context with a personal God or “magic” (which are actually pre-operational ideas). Because (usually) rationalists can not differentiate between the pre-rational and the trans-rational, choosing to believe that formal operational is the highest cognitive level available.
This is not really a dig at modernists or rationalists because they just do exactly what all the other operating systems have done before them, declare everyone below them as evil and everything above them as crazy. Those with mythical beliefs (organized religion) thinks that those with magical beliefs (pagans and shamans) are evil, and that rational atheists are crazy (or worse), and that holds true all the way up to and including post-modernism.
I think the most pedagogical explanation of this whole system is the AQAL map which clearly maps the different levels of cognition or development with their respective world views, and also explains the importance of differentiating between the internal subjective and the external objective.
Ps. Sorry if the post is rambling or incoherent, didn’t get any sleep last night, will be happy to clarify later if there are any questions.