Existential Rationalism: Handling Hume's Fork

​​

Author’s note

I was wrong about quantum computers in this book.

Entirely, embarrassingly so. I wanted them to illustrate something about the foundations of science. I believed the orthodox Copenhagen interpretation of quantum mechanics was wrong and that something on a Riemann surface couldn’t be operated before measurement.

The former still stands, but the latter does not: Quantum phases can be controlled with remarkable precision, for example through what is known as quasi-energy in Floquet qubits. This intriguing fact points toward as-yet-unknown deterministic phenomena that could underlie quantum probabilities. Such a possibility challenges the orthodox Copenhagen view, which categorically denies any underlying determinism.

While dualistic scientists may dismiss this as a metaphysical or even unscientific concern, within a nondualistic framework, it becomes central. By rejecting the notion of a mind-independent reality, nondualism crowns reason as the arbiter of science. And the very structure of rational inquiry—rooted in the principles of identity, non-contradiction, excluded middle, and sufficient reason—depends on the assumption of a deterministic order beneath appearances.

I thought I saw deeper because of the nondual awakening I had experienced. But it wasn’t me who woke up. It was something before the conception of space and time, and my self—as a working title for this pre-cognitive existence—did what it could to make sense of what had happened.

I was thrilled, inspired. Wanted to share what I had seen and help others see it too. But I didn’t have the skills—neither the words nor the understanding. And so I failed. People around me couldn’t see what had been shown to me.

Now I realize this is common. Everyone who’s had this kind of experience seems to go through the same thing. You can’t point out what can only be revealed by something pre-conceptual.

And yes, I was vain. My ego wanted to be seen and heard. So I overstepped and over-shouted myself. I wanted to explain why nonduality matters so deeply. Something dramatic could carry this message, so I turned to quantum computers.

I just couldn’t believe they could work because I didn’t understand their principles. And I assumed others were deceived because they lacked nondual awareness: a convenient conflation. But two wrongs don’t make a right: Just because the world is nondual and the ultimate truth is beyond conceptual grasp doesn’t mean we cannot aim our devices beyond the apparent Euclidean form in which the world presents itself.

So I had bitten off more than I could chew. Because quantum computing is possible—at least in principle. I just didn’t fully appreciate the physics.

As I write this in 2025, I find myself—echoing Wolfgang Pauli—misunderstanding quantum mechanics at a deeper level. The journey has been strange and beautiful. What once looked like a clean, Euclidean world now reveals itself as something richer: curved, folded—Riemannian.

I’ve come to appreciate Plato in a new light: how he urges us to use reason and geometry to move beyond the flickering shadows toward the true sun. The eyes of truth see the shadows as the veil.

So what about this book? Should you read it?

That’s up to you.

It more boldly and comprehensively unifies nondualism and Western thought than anything I could find. But it’s neither conventional nor polished; there may be more inaccuracies, even though I gave it my utmost. I’m just someone who writes to learn, finding out what I don’t know by putting my thoughts on the page. To me, sincerity is the starting point of originality, creativity, and insight. And I still believe the central discovery here stands firm: that nonduality, the all-encompassing truth, resonates deeply with reason.

Whatever speaks through this book—it wasn’t just me. And what it showed me was the discovery of a lifetime. I don’t regret following it unconditionally, as I still do today. These words of Plotinus, later recognized as the founder of Neoplatonism, encourage me:

Let him who can, arise, withdraw into himself, foregoing all that is known by the eyes, turning away forever from the material beauty that once made his joy . . . he must know them for copies, vestiges, shadows, and hasten away towards That they tell of.

As for the physics, I’m working on a new book that reflects a better understanding of quantum mechanics. The nature of our nondual world is sublime. And hidden in the Riemannian cracks of spacetime and the quantum world are even more compelling pointers to that truth.

In the meantime, maybe this imperfect beginning of a journey I started nine years ago can help or inspire you in ways I can’t fully express.

—Marcel Eschauzier, May 2025

1

​

When reason defeats dualism, it becomes personal

The vile grey of a Sunday morning had blossomed into full daylight. High up on my balcony, I saw how the tall buildings still trapped a veil of mist on the lake. The distant howling of a police car. A street dog barking. Almost twenty years earlier, I had left the Netherlands. My restlessness and curiosity had propelled me into a nomadic lifestyle, searching for existential clarity in the four corners of the world. A consultant job was my vehicle to live in several Asian, Latin-American, and Western countries.

​Traveling allowed me to patch some of my ignorance with real-life experience. My favorite learning method was making mistakes: painful but effective. Practical experience is an excellent starting point to answer, arguably, the most pressing existential question: How should I live life? The question raises related metaphysical and psychological issues. Who am I, and why do I experience life as I do? What can people know about the world anyway?

I also looked for answers in other ways, like reading about philosophy, psychology, neuroscience, and even physics. Curiosity with a low tolerance for cognitive dissonance is a taxing combination. What control do I have over my existence? What is the nature of my free will? How to live deliberately and suck out all the marrow of life?​[1] How to love? How to deal with disappointment? I found life thoroughly confusing. Until that moment on the balcony: The journey finally paid off when I got the clarity I had hoped for. I came home.

This book is about what I found.

As an engineer, I was pleased to learn from Western philosophy because it uses reason to seek answers. Engineers must be rational because the world is unforgiving for those who are not. I was particularly impressed by the philosophical work of David Hume (1711-1776). With inevitable logic, Hume shatters our hopes for certainty about anything in the world. He refutes the rationalist views of Plato and Descartes before him. Still, many illustrious thinkers after Hume could not relinquish the dream of conceptual certainty about the world. We will meet some of them in Chapter 9 Tall tales of higher truth. Hume sent rationalism into hibernation—but it isn’t dead, as we will find out.

It struck me that there is little consensus in Western philosophy’s answers to life’s great questions. As people, we are creatures of a single species inhabiting the same world. Why do our existential answers lack finality, and are they instead presented as if they were merely matters of discourse?

I extended my search to what Eastern philosophy had to offer. I must admit that, to this day, I remain a novice in this field. I have a thoroughly Western mindset. Even so, I found the relatively popular work of Alan Watts (1915-1973) highly instructive. He explains the essence of Oriental philosophy with British articulateness so that my Occidental mind could get it. Watts’s voice has been instrumental in familiarizing the West with Zen philosophy.

A pivotal moment was the insight I got that Sunday morning, standing on my balcony. It was a moment of absolute clarity. There was nothing supernatural or mystical about it, yet it was spiritual and life-changing. The Japanese Zen-Buddhist term for this experience of insight is satori. Suddenly I could answer the questions of who I am and why I experience life as I do. I resolved what philosopher David Chalmers (born 1966) calls the hard problem of consciousness.​[2]

A brief word to outline Chalmers’s position: He subscribes to the academically popular distinction between phenomenal consciousness and access consciousness. The former contains qualia, being the experiences from the immediate perspective of the subject, while the latter holds information that is not immediate and subjective. Access consciousness content is therefore accessible for cognition, communication, and behavior control. Chalmers considers that we understand the mechanics of access consciousness since they are merely easy problems of consciousness. The phenomenal experience remains unexplained, making it his hard problem of consciousness. We will return later to this topic.

Shortly after my satori experience, I also realized how to answer other existential questions. What can we know about the world? How to live life? Like satori, it was an experience of insight, and with this insight came all the answers. Later, when reading about it, I discovered I had found something known as Tao.

It became clear that I had been chasing my tail by searching for existential clarity. The answer was, as it were, my tail, and the harder I pressed to find it, the more it eluded me. I did not realize that the answer to my existential questions had been with me all along: in the search instead of separate from it.

​​​Satori’s knowledge theory (epistemological) aspect is that mind-independent knowledge is beyond human reach because we are not separate from reality. Satori is the counterintuitive discovery that the differences we conceive from the present change flow of our subjective conscious experience aren’t real. ​Multiplicity is an illusion. The notions we use to distinguish between people, objects, events, etc., such as time, space, cause, and effect, only exist in our minds. We cannot know what exists—we only know existence. The human world is nondual because we lack the extrasensory perception required to cross over to a mind-independent world.

Satori implies abandoning the hope of discovering reality. Finding Tao involves the subsequent inversion of the metaphysical model based on realizing that we have complete knowledge of our unconceived, immediate—so undeniable—subjective experience. We are at liberty to marvel at our experience for its own sake. We may rationally or otherwise explore its elements and patterns and share our findings.

So, the case seemed closed. I could be pleased to have found what I had been looking for. Surely, I wasn’t the first to experience satori and find Tao. Besides, Easterners are better culturally equipped to explain them than Westerners like me. I could continue my everyday life with an added touch of agreeable enlightenment.

However, something was puzzling me. Engineers like to understand how things work and solve problems. Why is the West unaware of nonduality? My satori experience awakened a latent wish to express myself creatively. I could investigate why this fundamental insight is missing from the Western collective consciousness and write a solution-driven book to explain it.

You are reading the result, but I must warn you that it may be unfamiliar. It is more personal than Western philosophy because nondualism insists on a first-person perspective. Yet, my engineer approach relies more on Western reason than traditional Eastern spiritual practice. Nondualism is also a vast subject because it is literally about . . . everything.

This first chapter’s personal story, interlaced with preliminary comments about nonduality, is meant as an introduction. The following chapters deal more systematically and thoroughly with nonduality and substantiate my claims. Please forgive me for my unorthodox approach: I wouldn’t have written this book if what I had to say was a common outlook.

✵

Dualistic metaphysics, meaning ontology (the study of what exists) and epistemology (the study of knowledge), not based on satori, is inaccurate because it is irrational. This affects us in seemingly unrelated areas and is more than just an academic discussion. The quantum computer may serve as a telling example of how deeply dualistic assumptions shape our technological ambitions.

Quantum computers seem to rest on a non-deterministic interpretation of quantum mechanics. If this interpretation turns out incompatible with nonduality, we may have to reassess the feasibility of such devices. Nondual metaphysics could require us to reconsider whether quantum information technology, as currently conceived, is grounded in a coherent understanding of nature. Will quantum computers go the same way as the once-hopeful perpetual motion machine?

I had assumed that something was out there that could solve my existential puzzle. I wanted to find a higher truth. Satori and Tao, instead, are predicated on our existence being one with reality. Searching for existential clarity distracts us from experiencing it. It has an inner-truth paradigm.

It became clear why my traditional Western thinking couldn’t provide answers. Through Watts, I understood what it truly means that we are one with reality. It follows that any attempt to describe reality is futile. Unlike real experience, reality implies a separation from the conscious mind. We don’t have access to a mind-independent truth because we are the experience of our participation in reality.

This seemingly reasonable belief in our ability to put at least some reality into words, equations, or measurement data is at the heart of Western dualistic confusion. It equals the assumption that objective knowledge beyond experience can be found. Such objective knowledge is a form of higher truth. But it is irrational to claim that we can know anything real at all because no mind can wrap itself completely around something it is an aspect of.

The Western world prides itself on being rational and has certainly been exemplary in achieving scientific and technological progress. However, it is struggling to apply rational thought to the subjective consciousness. It considers subjectivity a distraction from finding objective knowledge and exempts it from rational consideration.

With some notable exceptions that we will discuss, Western thought is inherently dualistic this way: The mere belief in our ability to have some knowledge of reality is evidence for understanding our conscious mind to be detached from reality. Accepting the principles of the evolution theory and a material explanation of the mind doesn’t yet demonstrate a truly nondualistic worldview.

There is a subtle but crucial difference between aspiring to find objective knowledge and striving for impartiality by filtering out overly personal biases and empathically imagining being in another person’s shoes. Their difference: Ultimate impartiality considers all individuals, ultimate objectivity none. Truth is essential in our lives but resides in our being, not beyond it. All knowledge we will ever have comes from our subjective experiences. Methods and experiments don’t answer questions; people do—even when we use tools like computers.

Paradoxically, the belief that we can know reality impedes a rational consensus about what we may consider true. Dualism provides an alibi for philosophical timidity. We have difficulty formulating philosophical answers since we cannot find rational arguments for making subjective judgments. The Western collective consciousness doesn’t know how to reconcile reason with subjectivity. Instead, it searches for deliverance from the stern gaze of reality and suspects to find it by warning the flocks about the temptations of treacherous perception.

People deny themselves sovereignty over the assessment of truthfulness by positing the possibility of objective knowledge. It annuls the prospect of any positive rational decision: No argument can ever tell what is right, and we may only provisionally suggest what could be wrong. The solution of choice is to ask for counsel from experts and invoke empirical evidence. I fully agree that evidence-based science has brought us a long way: It should continue to be cherished. Still, in its pure form, it can only falsify (and even that is problematic, as we will see) and not provide positive guidance. What if no empirical evidence is available or even feasible? Decisions of war and peace. Ideological dogma. Is our only hope to trust the experts?

Should not the experts still answer to reason, even when they have climbed higher than us on the Olympus of objective knowledge? Peer reviews are remarkably useful but do not turn theories into objective knowledge. Belief in the objective knowledge myth paralyzes us from arguing against irrational decisions before their disastrous consequences become empirically evident. It even beckons extremism because idealistic objective knowledge is deemed superior to subjective human life.

We yearn for an audience with reality, but she hides in her mirror palace. The reflections seem to extend an invitation to meet her. Alas! Looking behind the mirror, we must always conclude that we saw ourselves. Our guilt for not knowing reality is irredeemable because we cannot escape our subjectivity. The quest for objectivity ends in confusion. That confusion starts in the mind and should also be remedied by it.

The human susceptibility to the illusion of duality can be traced back to how evolution has shaped our minds. So, psychology and natural science are related topics: A better understanding of the workings of the mind improves our grasp of the physical world.

Cognitive science studies the mind interdisciplinary, combining scientific research of philosophy, psychology, neuroscience, and other areas. There are signs of a metaphysical mix-up in conventional, legacy cognitive science. Disentangling the notions can turn the vicious circle of confusion into a virtuous one of insight. Understanding the mind leads to existential clarity and vice versa.

Legacy cognitive science shares an issue with the natural sciences: It tends to objectify the subjective. I already mentioned Chalmers implying that not all consciousness is phenomenal: He distinguishes phenomenal consciousness from access consciousness. In his interpretation, the information in access consciousness is available for cognition and communication because, unlike the qualia in phenomenal consciousness, it also has relevance from a third-person point of view.

From the relevance in communication follows that the information in access consciousness corresponds between the sender and receiver. Hence, the context and meaning in the receiver’s access consciousness must come from the receiver’s memory.

However, it would be incorrect to consider all our memories part of our consciousness since we can only remember a minute amount of them at any given moment. And the memories that we presently do remember most definitely cause a first-person, phenomenal experience. When I imagine the color yellow from memory, I may vividly experience that color, even without seeing it.

So, should we entertain the possibility of experiencing anything that is not phenomenal? How do we solve the paradox of third-person experience when experience has, by its definition, a first-person perspective? Adequate metaphysics gives solace. We lack access to reality but not to real experience. Accurate integration of the philosophical and psychological mind models avoids suggesting an objective consciousness as terms like qualia and access consciousness implicitly do.

This book unmasks phenomenal consciousness as a pleonasm and proposes a model in which long-term memory renders the term access consciousness redundant. The distinction between easy and hard problems of consciousness is obsolete: There is only a single problem of consciousness. Existential rationalism settles this problem.

The proliferation of technical terms in psychology and the philosophy of mind is another sign of contemporary Western confusion. A belief