We begin with a narrow question: what is the simplest possible description of nondual experience? And how might one cultivate it?

David Loy’s 1988 book – Nonduality: A Study in Comparative Philosophy – offers a starting place. His project is to show how nondual traditions of Advaita Vedānta, Mahāyāna Buddhism, and Taoism, despite their disagreements, essentially allude to the same thing.

Loy’s approach is comparative. He studies these traditions side-by-side, finds the essentials they commit to, and notes where they agree and disagree.

We should note that “nonduality” is not confined to these traditions, and these traditions have no special authority. But they are among the oldest, most established, and most influential instances of nondual reports and philosophy. Their ideas can be triangulated to find common ground.

Phenomenal vs Metaphysical

For our purposes (not Loy’s) – one distinction is necessary:

A phenomenal claim describes what someone’s experience is like from the inside: “I felt totally absorbed in the music.” A metaphysical claim says what reality is for everyone: “we are all part of one consciousness.”

The trouble is that “nondual” experiences often arrive with a feeling of truth attached, and drift from “phenomenal report” to “metaphysical doctrine” in the same sentence.

While Loy examines metaphysical claims, we exclude them for two reasons. First, this is where the traditions diverge, and we are looking for agreement. Second, and most importantly, metaphysical claims aren’t necessary for grasping the experiential nature of nonduality and its implications for everyday life.

Here are examples of common metaphysical claims:

• Consciousness is fundamental / primary – the ground of reality, that from which matter and world derive.
• All is one / There is one universal consciousness – a single mind or awareness that everything is part of.
• The world / matter is illusory (māyā) – physical reality doesn’t really exist; only awareness is real.
• Universal mind is God / Godhead – consciousness is divine intelligence.

Any such claims are unnecessary for our inquiry.

If any terminology feels strange or hard to understand, hang in there – nonduality is counterintuitive by nature. We’ll summarize everything in the simplest possible terms at the end.

What Is Nonduality?

“Nonduality” is used loosely by many people to describe many things. Loy’s first chapter distinguishes three of the most common cases:

The negation of dualistic thinking. Our concepts come in opposed pairs – good/bad, being/nonbeing, success/failure, pure/impure – and the pairs are interdependent: each term is only intelligible relative to its opposite, so affirming one quietly maintains both. (The practical version: a life organized around purity is a life preoccupied with impurity.)

The nonplurality of the world. Drop the “representational overlay” (explained shortly) and the world stops presenting as a warehouse of discrete, self-standing objects. What the traditions call Brahman, Dharmakāya, or Tao is, at minimum, this: the world experienced whole rather than parsed.

The nondifference of subject and object. The deepest part of the representational overlay is the sense of a self – a subject standing apart from what it experiences. A whole world isn’t whole if the experiencer stands outside surveying it. So the deepest claim is that seer and seen are not two. Loy describes this as one of the most “striking and counterintuitive” claims in philosophy, illustrated with a quote from Plotinus:

“There were not two; beholder was one with beheld; it was not a vision compassed but a unity apprehended”.

Each type of duality collapses into the next. Dualistic thinking, then the separateness of the world, then the split between experiencer and experienced. Loy then moves to a core theory.

The Core Nonduality Theory

Loy pulls assertions from each tradition. Examples:

• Bṛhadāraṇyaka Upaniṣad: everything was undifferentiated, and became differentiated by “name and form.”
• Chuang Tzu: the ancients first didn’t know there were things; then knew, but made no distinctions; then distinguished; and “when judgements were passed, Tao was destroyed.”
• Padmasaṃbhava: as a thing is viewed, so it appears – to see multiplicity and cleave to separateness is to err.
• Śaṅkara: the universe is “an unbroken series of perceptions of Brahman” – hence nothing but Brahman.
• Yasutani, a twentieth-century Zen teacher, relaying an older master’s enlightenment line: hearing the bell, “there was no bell and no I, just sound.”

Several voices, spanning two thousand years and distant cultures. Finally, Loy arrives at his shared skeleton:

The world can be experienced two ways. In the dualistic mode, it shows up as a collection of discrete objects (one of which is “me”) interacting in space and time. In the nondual mode, the same world shows up undivided, with no experiencer standing apart from it. The bridge between the modes is superimposition: the dualistic world is the nondual world with a representational overlay.

We can now explore this core theory.

One Experience, Four Interpretations

At this point, we must grant that “experiencing the world in nondual mode” is possible, meaning, perception can feel like some unified experience and a sense of self fades.

Even if you can’t imagine it, what follows still works – the point is how such an experience can be interpreted in different ways.

Loy imagines several people having a nondual experience and describing it:

(These are short characterizations of actual philosophies. Don’t worry about understanding their exact meaning.)

Person 1: two things are real. There’s the awareness, and there’s the stuff happening in it – and these are utterly different kinds of things, forever. The watching never becomes the watched; the sky never becomes the clouds. Reality is a pure witness on one side and everything else on the other, and freedom is telling them apart. That’s the dualistic account of Sāṅkhya-Yoga.

Person 2: only the space of awareness is real. Think about it – the weather comes and goes, but the sky was there before, during, and after, unmarked. Whatever comes and goes can’t be the real thing – whatever never comes or goes must be. So the aware space alone is real – unborn, unchanging, without a single feature – and all the happenings are just appearances it puts on, the way a screen puts on a movie. That’s the nondual account of Advaita Vedānta.

Person 3: you’ve got it backwards – only the happenings are real. A space with no features? Something with no color, no shape, no location, no qualities at all is not a subtle presence – it’s nothing. What actually shows up, moment to moment, is just the events themselves: this patch of red, this sound, this thought — not a flower (that’s a label), and not an “I” watching the patches (that’s a label too). Just the arisings — with, surprisingly, a deep peace where the “I” used to be. That’s the nondual account of early Buddhism.

Person 4: you’re all doing the same thing wrong. Each of you took something from the experience and promoted it to a “thing” that really exists. The first made two things, the second made the space a thing, the third made every little event a thing. But nothing in the experience stands on its own; everything leans on everything else, so nothing qualifies as ultimately real. That’s the nondual account of Madhyamaka.

A similar core experience with four incompatible interpretations.

We can read this divergence as something subversive: while the core experience seems common, it is describable in mutually incompatible ways. Which one is true is a question the experience never answers. The disagreement again suggests that exact interpretations were never the important part.

What have we learned?

If anyone wishes to explore nonduality, consider that these traditions (and many others) are littered with conflicting metaphysical claims and dogma that muddy the water. Beyond trying to filter out the mud from each, we can run an entirely different experiment ourselves:

Cultivate the experience and let it speak for itself.

But how?

Meditation: Disarming the “Representational Overlay”

Returning to our “core theory”, there are two ways to see the world. A nondual world, and a dualistic world, which is a view of the nondual world with a “representational overlay”.

What is this representational overlay and how do we disarm it?

The book’s second chapter shows how training our attention is the gateway, and why meditation is the relevant instrument – not merely a mood-regulator or relaxation aid, but a technology aimed at quieting this representational overlay.

In ordinary perception, the overlay is invisible: a patch of color is never experienced as a patch of color – it arrives pre-packaged as a cup, an object, out there, mine. Some hidden mental process shows the cup and builds a sense of ownership. Buddhism, for example, points to the alternative: train the mind so that “in the seen there will be just the seen; in the heard, just the heard.” William Blake puts it like this: “If the doors of perception were cleansed, everything would appear to man as it is, infinite.”

The objection here is obvious: perception is always laced with concepts!

Nobody hears “pure noise” – for example – we hear a motorcycle. Gregory (psychologist) and Popper (philosopher) show ordinary perception as automatic and need-driven. For example, a hungry animal sees the world as food. Loy concedes this is true, but then he shifts the question: the representational overlay is automatized, and what is automatized was once learned, and what was learned can, in principle, be unwound.

Meditation, on this account, offers a means of unwinding.

In the psychologist Arthur Deikman’s term, de-automatization – “the undoing of automatization, presumably by reinvesting actions and percepts with attention.” Sustained attention with no task, no need, no point of view is one condition under which the representational layer, built to save attention, has nothing to do – and thins. Meditation is not the only method here, but one of the most established.

Deikman conducted two small concentration studies from the 1960s, in which all subjects, over repeated sessions, sat in a room and focused on a vase. After a long enough period, subjects reported the vase’s properties changing:

The color of the vase shifted to a deeper and more intense blue, frequently described as “more vivid.” “The adjective ‘luminous’ was often applied, as if it were a source of light.” “It was as if light were coming from it.” “It started radiating. I was aware of what seemed like particles…[that] seemed to be coming from the highlights there and right at me.” Another effect was an instability in the shape of the vase. Its size and/or shape changed; it appeared to become two-dimensional; and there was “a diffusion or loss of its perceptual boundaries.” Often the vase appeared to move: “rocking,” “drifting,” “wavering.” “The outlines of the vase shift. At that point they seem almost literally to dissolve entirely…and for it to be a kind of fluid blue…a very fluid kind of thing…kind of moving.”

The changes were not confined to the vase. Deikman’s own summary notes that the alterations ran “in the direction of fluidity and breakdown of the usual subject-object differentiation.” One subject described it directly: it felt “as though the blue and I were perhaps merging.” Another, gazing out a window after a session, reported “I wasn’t watching myself watching” – the antithesis, he said, of being self-aware.

Notably, these shifts were temporary, and could not be summoned on demand. When Deikman’s subjects tried to repeat an experience, the trying itself interfered. The representational overlay quiets when attention rests – and reasserts the moment the shift becomes the goal. Nondual perception, on this evidence, is not a switch that stays flipped. It comes in glimpses.

Deikman’s thread has since been picked up: the adjustability of the self/world boundary is now an active research program, from predictive-processing models of meditation to neuroimaging studies of meditators dissolving the sense of self.

What does all of this suggest?

What the studies establish is narrow but remarkable: the representational overlay is adjustable. The larger suggestion is that nondual perception is not some exotic attainment bolted onto the mind. It is what perception feels like when that learned overlay goes quiet. No study can settle this. It is checkable only in the first person – and it requires no metaphysical position whatsoever.

The “Representational Overlay” In Buddhist Terms

Here is more about the idea of “representational overlay”, directly from the book:

The Pāli sutras contain a wealth of material relating directly to perception, and, the distinction between perception with and without thought-construction is clearly critical.

A good account of this material is given in Edward Conze’s Buddhist Thought in India. Conze summarizes the analysis of perception found in the Pāli Canon into “three levels of the apperception of stimuli, to which three kinds of ‘sign’ correspond—the sign as (1) an object of attention, as (2) a basis for recognition, and as (3) an occasion for entrancement.

In the first stage, one “turns towards a stimulus”; attention is directed to what I call the “bare percept,” an act both active and passive because one chooses to turn toward it but one cannot determine what the sensation will be.

In the second stage, what has been perceived is recognized, “as a sign of its being such and such a part of the universe of discourse, and of habitually perceived and named things.” So the “bare” visual percept is now seen as a woman, or a table, or whatever, with all the respective connotations.

These connotations are elaborated in the third stage, which “is marked by the emotional and volitional adjustment to the ‘sign.’” The sign is now interesting to us and awakens volitional tendencies; I am attracted to the woman and wonder how I can meet her.

Of course, the whole sequence usually occurs so quickly that one is unable to distinguish one stage from another. So we take this tripartite series of distinct impersonal processes to be one simple mental event: seeing an attractive woman. Normally we are not aware of what it is like to experience just the first stage, for we never have experienced just that by itself. But to build upon sense-perceptions in this way is undesirable, according to the Buddha, and in the Majjhima Nikāya he describes various methods for “restraining the senses.” Conze summarizes: The task is to bring the process back to the initial point, before any “superimpositions” have distorted the actual and initial datum.

Why Bother? Peace. Clarity.

Loy’s conclusion turns to values, and here we focus on two points.

The first benefit is peace. It seems the representational overlay can produce suffering, and that suffering can disappear when the overlay quiets. Loy paraphrases Spinoza: “blessedness is not the reward of virtue but virtue itself. The other side of this is that suffering is not the punishment for evil, but evil itself.” Trimmed of metaphysics, the claim is modest and testable: a baseline of peace is available that does not need to be manufactured, because it is what remains when attention rests. Loy illustrates it this way: “life is nothing but a series of such timeless experiences: a sip of coffee, a few words with a friend, a walk down a path” – and someone who cannot trust the world enough to forget himself into such moments “condemns himself to watch his life ooze away.”

The second benefit is clarity over what we don’t control – which, on inspection, includes most of the mind. Loy’s chapters on action and thought converge on one finding: thoughts and intentions arise on their own, no orchestrating self is discoverable behind them, what we call the thinker is assembled after the fact. His conclusion reframes the entire problem from a war of will against unwanted contents to a question of how clearly the contents are seen. Practically: once the mind is seen to run itself, its productions lose their automatic authority. They can be engaged, declined, or left alone – related to, rather than obeyed or fought.

The peace of the first benefit funds the clarity of the second. It becomes obvious how much of what the mind serves up was never worth entertaining, and how much of life was spent entertaining it. That recognition reaches further than it first appears – into identities and long-held aims, not just passing moods – and it accumulates. While sudden glimpses may be vivid – lasting change is born from many glimpses, metabolized over years. The book’s word for the transition is liberation. We can describe it more humbly: a durable shift in what one takes seriously.

Summary: What Is Nonduality?

Let’s return to our question:

What is the simplest possible description of nondual experience?

When Loy scans the traditions for overlap, this is the gist:

The world can be experienced two ways. In the dualistic mode, it shows up as a collection of discrete objects (one of which is “me”) interacting in space and time. In the nondual mode, the same world shows up undivided, with no experiencer standing apart from it. The bridge between the modes is superimposition: the dualistic world is the nondual world with a representational overlay.

How can we experience nondual mode? Turn down our representational overlay.

How can we turn down this representational overlay? Attention and meditation.

Why would we do this? When we see so much of our mind (thoughts, feelings, assumptions, narratives, impulses, self) arises on its own, we don’t have to take it personally. In everyday life, we can engage with our mind more carefully.

Before: I feel this. I think this.

After: Here is a feeling. A thought. Are they true?

An Anecdote

I started meditation practice in 2020. My intentions were simple. Explore my mind and see what I find. I meditated 4-5 times per week, starting with guided meditations, then on my own.

I consider myself fortunate, because “nonduality” was not a target I was aiming for. Instead, I was simply meditating and taking stock of subtle changes over time.

Sometimes this change was during meditation. For example, noting the inherent peace when I stopped paying attention to all the clutter in my mind.

Sometimes this change was outside meditation. For example, watching myself getting distracted with things that didn’t really matter, and removing worries from my life that were wasting time.

Eventually, this culminated in some vivid experiences. For example, somewhat spontaneously, the nature of desire came into focus – how the happiness that comes from so many kinds of desire is fleeting. Or in another example, I was looking around at all the objects in the room, and realizing I was experiencing a mural inside perception – not necessarily a depiction of some “objective world”.

The point being, as the months passed by, my “representational layer” was flickering at different intensities, offering glimpses into nondual perception, and thus, impacting how I relate to myself, the world – and how I want to be.

This is approximately three years of my life distilled. It was not some “mega moment” of insight. It was a slow background practice of meditation and contemplation, and mini-moments, which gradually shifted perspective. Only later, searching for similar accounts, did I deliberately explore the nonduality landscape and attempt to reconcile it with what I had been experiencing.

What I learned: hold nonduality descriptions lightly. Beware of speculative metaphysics. Most of all, cultivate these experiences for yourself with meditation and contemplation.

Weaknesses

Nondual experience, by its nature, is perception prior to the representational overlay. This includes thoughts and language – the very things we need to describe it. Ironically then, any written account of nonduality must be skewed and incomplete.

A stronger objection goes further: training shapes the experience itself, so that practitioners tend to find what their tradition taught them to look for. If that’s right, the traditions never had one experience to describe in the first place.

However, the experience itself has been reported for over two thousand years, and those reports are approximately similar. To completely ignore this would miss something. Either way the conclusion is the same: look for yourself.

Loy is aggregating many imperfect accounts, and further admits his own imperfection. In his words, his selection is “unsystematic and intuitive.” Some claims were used while others were ignored. Similarities were emphasized while disparities were “seldom remarked.” This leaves ample room for scholars to debate his selection and conclusions.

Here we must return to the motivation for this article:

What is the approximate essence of the nondual experience, and how might one cultivate it?

In this regard, Loy’s distillation is rare and valuable.

Resources

This article distilled the nature of nonduality according to major traditions – and described a high-level approach to cultivate nondual perception – but did not provide specific tools. On that end, here are some places to start.

We cannot escape the skew of descriptions, but we can hold them as lightly as possible, and be our own authority. These projects explicitly support that view.

• The Waking Up App – A mindfulness meditation app. Start with the introduction course, and wander to lectures, talks, discussions.
• Mindful Glimpses – A mindfulness app that works with “pointers” or “glimpses” – short instructions designed to quiet the representational overlay.
• Why Buddhism Is True – Not an endorsement of Buddhism, but a tour of how so many aspects of Buddhism seem “true” – as witnessed by a non-Buddhist.
• Self-Investigation.org Discussion Forum – An online community to discuss this material and related experiences.