What is "Self"?

3+ years ago, Thusness/Passerby wrote this to explain a text to someone:

Life (Self) is nothing other than the continuous flow of the Now Moment.
The Now Moment ceases as it arises. This moment must completely ceased
and serves as the CAUSE for the next moment to arise.
Therefore Self is a process of series Self1, Self2, Self3, Self4, Self5, Self6...etc
A fixed entity 'Self' does not exist, what really exists is a momentary Self.
Under deep meditation, one is able to observe and sense the karmic and mental factors from moment to moment,
it is these factors that are succeeded from moment to moment and life and life but not a fixed entity.

He further adds a clarification two weeks ago:

After cycles of refining and stabilizing non-dual experiences,
karmic propensity too reveals itself as empty.
Momentum arises spontaneously and subsides instantaneously;

Yet has never in anyway obscured its own luminosity.
All experiences though diverse are always so,
this is the unborn always found present in all diversities.
Never personify or objectify 'unborn' into an entity,
but see all phenomena that dependently originates as luminous and empty.
If any non-dualist finds difficulty in sustaining non-dual experiences,
this the pathless path of spontaneous presence and natural clarity.

As Thusness mentioned, do note that an equal emphasis must be place on its 'empty nature' apart from its luminosity.

Another great article on "What Is The Me?" by Toni Packer can be found at http://www.springwatercenter.org/teachers/packer/articles/whatisme/.

Regarding the link between how we perceive a separate self and our karmic propensities (deep conditionings/momentum), please read The Spell of Karmic Propensities.
Related: The Breakthrough

(The following is written by Ajahn Amaro on the teachings of Non-Duality, Anatta and Emptiness by Buddha. Also see: Thusness/PasserBy's Seven Stages of Enlightenment)

Ancient Teachings on Nonabiding


This principle of nonabiding is also contained within the ancient
Theravada teachings. It wasn’t just Ajahn Chah’s personal insight
or the legacy of some stray Nyingmapa lama who wandered
over the mountains and fetched up in northeast Thailand 100
years ago. Right in the Pali Canon, the Buddha points directly
to this. In the Udana (the collection of “Inspired Utterances”
of the Buddha), he says:

There is that sphere of being where there is no earth,
no water, no fire, nor wind; no experience of infinity
of space, of infinity of consciousness, of no-thingness,
or even of neither-perception-nor-non-perception; here
there is neither this world nor another world, neither
moon nor sun; this sphere of being I call neither a coming
nor a going nor a staying still, neither a dying nor
a reappearance; it has no basis, no evolution, and no
support: it is the end of dukkha. (ud. 8.1)

Rigpa, nondual awareness, is the direct knowing of this. It’s
the quality of mind that knows, while abiding nowhere.

Another teaching from the same collection recounts the story
of a wanderer named Bahiya. He stopped the Buddha on the
street in Savatthi and said, “Venerable Sir, you are the Samana
Gotama. Your Dharma is famous throughout the land. Please
teach me that I may understand the truth.”

The Buddha replied, “We’re on our almsround, Bahiya. This is
not the right time.”

“Life is uncertain, Venerable Sir. We never know when we are
going to die; please teach me the Dharma.”

This dialogue repeats itself three times. Three times over, the
Buddha says the same thing, and Bahiya responds in the same
way. Finally, the Buddha says, “When a Tathagata is pressed
three times, he has to answer. Listen carefully, Bahiya, and
attend to what I say:

In the seen, there is only the seen,
in the heard, there is only the heard,
in the sensed, there is only the sensed,
in the cognized, there is only the cognized.
Thus you should see that
indeed there is no thing here;
this, Bahiya, is how you should train yourself.
Since, Bahiya, there is for you
in the seen, only the seen,
in the heard, only the heard,
in the sensed, only the sensed,
in the cognized, only the cognized,
and you see that there is no thing here,
you will therefore see that
indeed there is no thing there.
As you see that there is no thing there,
you will see that
you are therefore located neither in the world of this,
nor in the world of that,
nor in any place
betwixt the two.
This alone is the end of suffering.” (ud. 1.10)

Upon hearing these words, Bahiya was immediately enlightened.
Moments later he was killed by a runaway cow. So he was
right: life is uncertain. Later Bahiya was awarded the title of
“The Disciple Who Understood the Teaching Most Quickly.”

“Where” Does Not Apply

What does it mean to say, “There is no thing there”? It is talking
about the realm of the object; it implies that we recognize that
“the seen is merely the seen.” That’s it. There are forms, shapes,
colors, and so forth, but there is no thing there. There is no real
substance, no solidity, and no self-existent reality. All there is,
is the quality of experience itself. No more, no less. There is just
seeing, hearing, feeling, sensing, cognizing. And the mind naming
it all is also just another experience: “the space of the
Dharma hall,” “Ajahn Amaro’s voice,” “here is the thought,
‘Am I understanding this?’ Now another thought, ‘Am I not
understanding this?’”

There is what is seen, heard, tasted, and so on, but there is no
thing-ness, no solid, independent entity that this experience
refers to.

As this insight matures, not only do we realize that there is
no thing “out there,” but we also realize there is no solid thing
“in here,” no independent and fixed entity that is the experiencer.
This is talking about the realm of the subject.

The practice of nonabiding is a process of emptying out the
objective and subjective domains, truly seeing that both the
object and subject are intrinsically empty. If we can see that both
the subjective and objective are empty, if there’s no real “in
here” or “out there,” where could the feeling of I-ness and meness
and my-ness locate itself? As the Buddha said to Bahiya,
“You will not be able to find your self either in the world of this
[subject] or in the world of that [object] or anywhere between
the two.”

There is a similar and much lengthier exchange between the
Buddha and Ânanda in the Shurangama Sutra, which is a text
much referred to in the Ch’an school of the Chinese tradition.
For pages and pages the Buddha asks Ânanda, in multifarious
ways, if he can define exactly where his mind is. No matter how
hard he tries, Ânanda cannot establish it precisely. Eventually
he is forced to the conclusion that “I cannot find my mind anywhere.”

But the Buddha says, “Your mind does exist, though,
doesn’t it?”

Ânanda is finally drawn to the conclusion that “where” does
not apply.

Aha!

This is the point that these teachings on nonabiding are trying
to draw us to. The whole concept and construct of where-ness,
the act of conceiving ourselves as this individual entity living
at this spot in space and time, is a presumption. And it’s only by
frustrating our habitual judgments in this way that we’re forced
into loosening our grip.

This view of things pulls the plug, takes the props away, and,
above all, shakes up our standard frames of reference. This is
exactly what Ajahn Chah did with people when he asked, “If you
can’t go forward and you can’t go back and you can’t stand still,
where can you go?” He was pointing to the place of nonabiding:
the timeless, selfless quality that is independent of location.

Interestingly enough, some current scientific research has
also reached a comparable conclusion about the fundamental
nature of matter. In the world of quantum physics, scientists
now use such terms as “the well of being” or “the sea of potential”
to refer to the primordial level of physical reality from
which all particles and energies crystallize and into which they
subsequently dissolve. The principle of non-locality in this realm
means that the “place where something happens” cannot truly
be defined, and that a single event can have exactly simultaneous
effects in (apparently) widely separated places. Particles can
accurately be described as being smeared out over the entirety of
time and space.

Terms like “single place” and “separate places” are seen to
apply only as convenient fictions at certain levels of scale; at the
level of the ultimate field, the sea of quantum foam, “place” has
no real meaning. When you get down into the fine, subatomic
realm, where-ness simply does not apply. There is no there there.
Whether this principle is called nonabiding or non-locality, it’s
both interesting and noteworthy that the same principle applies
in both the physical and mental realms. For the intellectuals and
rationalists among us, this parallel is probably very comforting.

I first started to investigate this type of contemplation when I
was on a long retreat in our monastery and doing a lot of solitary
practice. It suddenly occurred to me that even though I might
have let go of the feeling of self—the feeling of this and that
and so on—whatever the experience of reality was, it was still
“here.” There was still here-ness. For several weeks I contemplated
the question, “Where is here?” Not using the question to
get a verbal answer, more just to illuminate and aid the abandonment
of the clinging that was present.

Recognizing this kind of conditioning is half the job—
recognizing that, as soon as there is a here-ness, there is a subtle
presence of a there-ness. Similarly, establishing a “this,” brings
up a “that.” As soon as we define “inside,” up pops “outside.”
It’s crucial to acknowledge such subtle feelings of grasping; it
happens so fast and at so many different layers and levels.

This simple act of apprehending the experience is shining the
light of wisdom onto what the heart is grasping. Once the defilements
are in the spotlight, they get a little nervous and uncomfortable.
clinging is the focus of our awareness, it can’t function properly.
In short, clinging can’t cling if there is too much wisdom around.
Clinging operates best when we are not looking. When
clinging is the focus of our awareness, it can’t function properly.
In short, clinging can’t cling if there is too much wisdom around.