Self is a good model at the right level of abstraction
Non-dualism is central to many eastern contemplative traditions. And as a long time practitioner of Vipassana and as someone who subscribes to the idea of nothingness as a manifestation of a single overarching unity, or the lack of loci, or more appropriately lack of differentiation, I have no reason to doubt non-dualism as the be-all and end-all theory of everything. But in the last couple of months, especially after having read certain books(A world beyond physics by Stuart Kauffman, Fabric of Reality by David Deutsch, Book of why by Judea Pearl, Notes on the synthesis of form by Christopher Alexander), I have come to realize that there is more to it than meets the eye. Let me explain.
Abstractions play a vital role in our lives. In fact, it has been central in bringing about the cognitive revolution that we know of today. Abstractions allow us to think beyond irreducible states, and it is abstractions that help us understand the validity of a concept with respect to the level (of emergence/abstraction) it is being used in. Although we have always had abstractions in nature, I am talking specifically about the abstraction in the human communication systems(languages, ideas, symbols, etc). I mean what is stopping us from referring to each other by our uniquely identifiable DNA sequence, or for the matter reducing the validity of humanness to its bare minimum i.e., atoms/sub-atomic particles. What is so special about you or me that we deserve a name? Why should I respect you, aren't you just a bunch of atoms in a particular configuration?
These are the classic examples of reductionism-based thinking. Also a cause for nihilism. But what most people fail to understand is that most concepts acquire any meaning only at a particular level of abstraction/emergence. Take, for example, the idea of causality. Reductionism would have you believe that the idea of causality is just hokum. People who espouse reductionism will reason all the way back to the big bang and pre-big-bang to prove the constructed nature of space-time. But at a particular level of emergence, causality does have predictive powers. For eg. If you have a light source at a particular height and distance from an object, you know it will cast a shadow of a certain length. You can find the length of the shadow using high-school trigonometry, but so can you find the height of the object using the length of the shadow. So does it mean that in the latter case, the shadow is causing the object to materialize?
This is to show that almost every concept that has any explanatory/predictive power must be evaluated in the right context instead of expecting it to be valid across all levels of abstractions at all times. And this is very essential to understanding the false-dichotomy that non-dualism invokes. That is, if the appeal to atoms and big-bang is downward reductionism, shouldn't appeal to an overarching unity or nothingness as the ultimate reality be considered a form of upward reductionism. In a non-dualistic ontology, there is never a differentiation. The truth is always "this" and nothing more. Note that I am not saying that this is wrong. I see the motivation here. "This is and this cannot be known" is a very powerful idea, but the problem here is there is no way to reconcile the real-world developments as we know and experience them with an all-encompassing and ever-present truth. The notion of an overarching unity reduces everything by terming them as contents of an all-encompassing space of awarness(a.k.a consciousness)Note: By awareness, we are not talking about your ability to be aware, but the notion of pan-awareness or consciousness. How is it any different from reducing everything to atoms or dragging things back to pre-big-bang times?
Another advantage to abstraction is the ability to embrace fallibilism. All knowledge is conjectural, so what is to say that one theory is correct and the other isn't. Deutsch explains this particularly well in his book The Beginning of Infinity through the idea of Hard to Vary explanations. Deutsch claims that all knowledge creation simply follows the process of conjecture and criticism. It is the error-correcting mechanism that makes an explanation a good explanation vs a not-so-good explanation. This is to say that something like the Darwinian idea of natural selection is just a better explanation compared to say Lamarckism, and it is perfectly possible that there might come a time in the future when we can explain evolution much better, but it must be understood that error correction has to be a fundamental moral obligation no matter the field of inquiry.
The beauty of this line of thinking is that it fits perfectly well with the idea of reconciling concepts with the level of emergence. Let's take again the example of Darwinian natural selection. If you think about it you could just explain(handwave?) away the entire process of evolution in terms of electrons and protons doing what they do. You could even attribute the cause to the complexity of interactions between these particles, but does it really explain anything though? It seems to me that for an explanation to be a good explanation, it should not just embrace fallibility and error correction, it should also pay attention to the level of abstraction in which it has any explanatory powers. And I think this is something both the downward reductionists and upward reductionists fail to incorporate in their philosophy.
FWIW, as someone who has practiced both Vipassana and Dzogchen for a long time, I think I have a pretty good understanding of the (subjective?) experiential aspects of the teaching. And yes, upon closer inspection the self or the center disappears in pretty much all the traditions I mentioned above, but whether you take a look at the pointing out instructions(a.k.a intellectual exercises) of Dzogchen or the grueling body scans of vipassana, you will notice that there is never a question of fallibilism. What is to say that this interpretation of your subjective awareness is the correct interpretation? What about the possibility of misinterpretations?
Another major issue is the emphasis on the persistence of these states without paying attention to the emergent aspects of life i.e., even if we conceded that there is no self as we experience prior to the realization of this all-encompassing awareness, what is to say that the constructed nature of self isn't of any value. Isn't it like causality all over again?
My updated view after having read all the aforementioned books is that fallibilism has to be central to one's worldview, whether it is subjective or objective. And "self" upon a deeper examination seems to me like a good model that helps you navigate the "real world" as you experience it. To conflate the idea of self with centerlessness is to conflate two different levels of abstractions. Yes, there is a subjective sense of non-differentiation when you meditate deeply, but also understand that self isn't meant to explain that, just like causality isn't meant to explain why you can use shadow length to determine the height of the object but cannot say that the existence of shadow is what creates the object. Also, this doesn't really say anything about whether this centerless, undifferentiated, overarching unity is indeed all there is to it, meaning, if you really follow fallibilism there is no ultimate truth to be found. There are only error-corrected explanations!
"All life is problem solving" — Karl Popper