Nirvikalpa samadhi is different. It is the different degrees of meditative absorption and depths of absorption in the pure presence and pure consciousness of Self, which makes up the different levels of nirvikalpa samadhi. That is to say, even after I AM, there is the different degrees and intensities of the oceanic, blissful qualities of Self that are especially deep when one is able to develop the mastery of meditative strength and stability in absorption of Self. So as I wrote in the AtR guide, meditative samadhi and absorption is one area that one can develop after the I AM realization.

However, the path to the effortless total presence and the self-liberating nature of empty clarity lies not just in the development of samadhi. It lies in attaining key insights and wisdom into anatman (no-self), dependent origination and emptiness. Therefore I also wrote, for those that attained the realization of I AM, they should look into the four aspects of I AM, the nondual contemplations, the two stanzas of anatta. These will bring the practitioner into further breakthroughs and insights. There is a chapter on samadhi post-I AM in the longer AtR guide ( https://www.dropbox.com/scl/fi/r7ttb5ajovu7yjdrl9t9c/Awakening-to-Reality_-A-Guide-to-the-Nature-of-Mind-3-SEPTEMBER-2023_DRAFT.docx?rlkey=dica15mskmj4v3atiqrpo0zn0&dl=0 ). But in general for most people I recommend starting with the shorter AtR practice guide https://www.awakeningtoreality.com/2022/06/the-awakening-to-reality-practice-guide.html .

Edmond cigale wrote a document detailing his experiences with different levels of nirvikalpa samadhis prior to his realization of nondual and anatman ( https://app.box.com/s/7u47emus4osjxzpnqs03 ), I helped to point out anatman to him many years ago. His document is a good read detailing his own journey and experiences.

As for the realization of anatta..  The realization of anatta is not a samadhi state. As someone wrote very long ago, asking whether his indepth experience with nirvikalpa samadhi was related to Thusness’s insights into no-self. Thusness replied then, in 2007, “So persistent, it might not be fruitful but so be it! 

It will be quite misleading if I tell you yes. As it is not quite the same as the Sahaja Nirvikalpa Samadhi you are referring too. ‘No-self’ (in Buddhism and in reality) is not a state to be attained nor is there a state to reside, it is the ‘nature’ or a characteristic that is exhibited in phenomenon arising at all time. Always so and truly so. 

…

Unless the fabric and texture of awareness as 'forms', as 'things' is sufficiently experienced, we might not be talking the same stuff. “

One key insight into effortless total presence is the insight into anatman. In the anatman realisation, it is seen that the so called 'background' consciousness is that pristine happening. There is no a 'background' and a 'pristine happening'. During the initial phase of non-dual, there is still habitual attempt to 'fix' this imaginary split that does not exist. It matures when we realized that anatta is a seal, not a stage; in hearing, always only sounds; in seeing always only colors, shapes and forms; in thinking, always only thoughts. Always and already so.

Over a decade ago, someone at the I AM stage commented that the Thusness stages sounded like different levels or absorption or jhana.

John Tan/Thusness and I wrote back then,

PasserBy

Dec 30, 2007, 9:37:00 PM

Hi Jhanananda,

Thanks for dropping by your comments. I have a somewhat different understanding on how they are mapped to the Buddhist Anatta experience and will thus be sharing my understanding. 

Thusness six stages of enlightenment are short summaries of his gradual insights into the non-dual (aka Anatta/no-self in Buddhism), emptiness (dependent origination) and self-liberated nature of our pristine awareness. As spontaneous self-liberation is commonly misunderstood, Thusness has always stressed that before the arising of the intuitive insights into our non-dual and emptiness nature, it is best not to discuss about it. For the purpose of this comment, I will only discuss the Anatta and the strength of propensity that blinds.

Indeed self-liberation cannot be understood before the experience of non-duality and emptiness nature of our pristine awareness. However after the stability of these 2 insights, nothing needs to be said as the ‘mere manifestations of these inseparable characteristics as arising phenomena’ is itself liberation.

First I do not see Anatta as merely a freeing of personality sort of experience as you mentioned; I see it as that a self/agent, a doer, a thinker, a watcher, etc, cannot be found apart from the moment to moment flow of manifestation or as its commonly expressed as ‘the observer is the observed’; there is no self apart from the arising and ceasing. A very important point here is that Anatta/No-Self is a Dharma Seal, it is the nature of Reality all the time -- and not merely as a state free from personality, ego or the ‘small self’ or a stage to attain. (related article: http://awakeningtoreality.blogspot.com/2007/07/bernadette-roberts-interview.html) This means that it does not depend on the level of achievement of a practitioner to experience anatta but Reality has always been Anatta and what is important here is the intuitive insight into it as the nature, characteristic, of phenomenon (dharma seal). 

To illustrate further due to the importance of this seal, I would like to borrow a quote from the Bahiya Sutta (http://www.accesstoinsight.org/tipitaka/kn/ud/ud.1.10.irel.html) 
‘in the seeing, there is just the seen, no seer’, ‘in the hearing, there is just the heard, no hearer’… 
If a practitioner were to feel that he has gone beyond the experiences from ‘I hear sound’ to a stage of ‘becoming sound’ or takes that ‘there is just mere sound’, then this experience is again distorted. For in actual case, there is and always is only sound when hearing; never was there a hearer to begin with. Nothing attained for it is always so. 

Well said! Just a little more emphasis: This is the seal of no-self and can be realized and experienced in all moments; not just a mere concept.
For a non dualist that has gained sufficient stability, practice takes a very different role. This is due to the thoroughness of seeing through the illusionary views of the sense of self, the entire mechanism that causes the split and the mechanism of how it ‘blinds’. Therefore after knowing the real cause and conditions, a non-dualist cannot resort back to a dualistic approach towards liberation and practice and meditation take very different roles. It becomes instant, dynamic, spontaneous and direct. 

Before the awakening of prajna wisdom, there will always be an unknowing attempt to maintain a purest state of 'presence'. For this is how the dual mind works. This purest state of presence is the 'how' of a dualistic mind -- its dualistic attempt to provide a solution due to its lack of clarity of the spontaneous and emptiness nature of the unconditioned. It is critical to note here that both the doubts/confusions/searches and the solutions that are created for these doubts/confusions/searches actually derive from the same cause -- our karmic propensities of ever seeing things dualistically (also see my other friend Longchen’s article http://www.dreamdatum.com/meditation-spontaneous.html where I posted two of his articles including ‘How is nonduality like?’ in this forum)

‘Purest’ because it is the limit of the thought realm; beyond that is inconceivable by the conceptual mind. The mind conjures out this ‘state’ as it cannot penetrate its own depth. It does not allow itself to cease completely.


Within the Theravadin tradition, I understand the experience of (Thusness’s) Stage 4 which is the beginning of realising non-duality to be the beginning of the third path/stage of enlightenment (see http://awakeningtoreality.blogspot.com/2007/12/heart-sutra-model-of-four-paths.html
and http://awakeningtoreality.blogspot.com/2007/07/non-duality-models-of-enlightenment-by.html)  (Comments by Soh: this is MCTB model, not the Buddha’s fetter model) and also corresponding in terms of realisations to the beginning of ‘One-Taste’ in the Bodhisattva bhumi models. From here on it is a matter of how deeply the insights of nonduality/nonself and emptiness has penetrated into our consciousness and replaced our dualistic way of knowing due to karmic propensities.

This is known as the ‘turning point’ in Lankavatara Sutra.


The author of the two articles (a Theravadin teacher) mentioned above also said in the Heart Sutra Model of the Four Paths regarding the third path, “That said, the concept of Nirvana now seems to generally apply to the phenomenal world as well as the attainment of Fruition, though there is still something clouding the waters. Those of third path will have a direct understanding of what is meant by non-duality, the “intrinsic luminosity” of phenomena and of “interdependence” that is far more direct and clear than the somewhat intuitive understanding of those of first and second path. This holds up quite well until they get into another progress cycle.”, and, 

“It requires great deal of trust in reality as well as a fairly new realm of understanding. Paths that emphasize “surrender to the will of God” might well have an easier time with this transition. Simply emphasizing the Third Characteristic, that all things simply happen on their own, works just as well.”

Great insight by Dharma Dan!

That said, I never doubted the importance of “concentration & absorption” in spiritual practices. It is also true that the strength of uninterrupted concentration may not be there even for one with insights (especially when one have just begun to have nondual realisations and the insight into emptiness is not yet there), and it has to go hand in hand with their new found insight of nonduality for stability, and also move into various graduation of nonduality. As mentioned earlier, there are no stages/appearances that are purer than any others – every state is equally pure and non-dual in nature. When the mind grasps pure awareness as ‘formless’, ‘thoughtless’, ‘attributeless’, and as the background reality.... the ‘fabric’ and ‘texture’ of pristine awareness as ‘forms’ is then missed. Nevertheless, whatever you commented is crucial especially for the first 3 (Thusness’s) stages of experience, and in these stages the problem would certainly be the lack of sustained meditation concentration as well as the tendency of trying to grasp intellectually... which is also why Thusness often emphasizes the importance of sitting. 

The first 3 stages are before the arising of non-dual insight and the purpose of sustainability is to create sufficient gap between 2 moments of thoughts to allow the sensation of contrast between conceptual/non-conceptuality for the thinking mind to realize the possibility of going pre-symbolic thereby loosening its stubborn grips of a dualistic framework. 
Sustained bare attention also gave rise to the realization that ‘inner’, ‘outer’, ‘space’, ‘time’ and even ‘body’ and ‘mind’ are all mere constructs. Freeing from these constructs, also give rise to the condition for non-dual insight to arise. 
For the first 3 stages, practice takes the form of striving towards a certain stage of perfection whereas stages 4 onwards, practice moves from ‘efforting’ to natural luminosity and spontaneity. 

As to what led to jhanic bliss, I would like to say that regardless of samatha or vipassana practices, true blissful absorptive experiences are the result of dissolution of self and subject-object split. For non-dualists, this blissful absorptive experience takes a form of clarity-absorption which is mentioned in one of the Thusness posts in my friend Longchen’s forum (http://awakeningtoreality.blogspot.com/2007/05/different-degrees-of-non-duality.html). It is difficult to explain and I will not speculate further what that is beyond me. It should also be mentioned however at a deeper level of non-dual realisation, when true spontaneity is realised, and psychological death is complete, one will overcome the tendency of grasping on the conscious and the three states (waking, dream, deep dreamless sleep) becomes one. He will also realize that it is needless to maintain an uninterrupted state of conscious witnessing awareness when the true nature of Awareness is revealed, as Thusness and Longchen have said.

Well said! Speak no more and experience fully! 
Rest.

- the 2007 comments can be found in the commenters section of https://www.awakeningtoreality.com/2007/03/thusnesss-six-stages-of-experience.html 

——

Wrote in 2018：

"If someone talks about an experience he/she had and then lost it, that's not (the true, deep) awakening... As many teachers put it, it's the great samadhi without entry and exit.

John Tan: There is no entry and exit. Especially for no-self. Why is there no entry and exit?

Me (Soh): Anatta (no-self) is always so, not a stage to attain. So it's about realisation and shift of perception.

John Tan: Yes 👍

As John also used to say to someone else, "Insight that 'anatta' is a seal and not a stage must arise to further progress into the 'effortless' mode. That is, anatta is the ground of all experiences and has always been so, no I. In seeing, always only seen, in hearing always only sound and in thinking, always only thoughts. No effort required and never was there an 'I'.""

- excerpt from https://www.awakeningtoreality.com/2021/07/anatta-is-dharma-seal-or-truth-that-is.html

——-

The atr guide named four sub stages of Self. All these do not go beyond the I AM stage but are instead depths of samadhi within the I AM phase. Nondual and anatta are different varieties of insights.

———

Someone asked, “ different samadhis? that is interesting, are they abiding or non-abiding? effortful or without effort?”

Soh replied, 

“The different levels of nirvikalpa samadhi are expressed well by edmond cigale who realised anatman after some contemplation on the pointers i wrote to him. https://app.box.com/s/7u47emus4osjxzpnqs03?mibextid=Zxz2cZ

Supposedly, the highest level if nirvikalpa samadhi, called sahaja nirvikalpa samadhi, is supposed to be effortless. That is supposed the highest stage in hindu yogic systems.

However as Thusness wrote, 

“

[24/3/19, 11:17:05 PM] John Tan: From the perspective of clarity, it is true that Buddhism anatta and emptiness is more profound and deep… lol. But still good to caution about respecting all religions and practice. Why empty clarity is only pointed out in buddhism. So although it is true about all points to pure consciousness, it is realizing the emptiness that is the prajna eye to allow us to clearly see the empty nature of clarity. Otherwise we will most likely land in alaya or [be] required to still in deep stillness of samadhi.

(On this point, I was reminded of something John Tan said back in I think 2012:

"Every religion is talking about consciousness.  It is the nature of consciousness that is important.  It is like talking about “Soh'' from different people. Of course all is pointing to "Soh" but when someone say he is an American, has 10 sisters and is now studying in India… we cannot say that he is correct and it is the same because ultimately we are talking about "Soh".")”

“Yes sahaja samadhi but that remain as "experience".  Just like in taoism, it is all about naturalness 自然 and non-action (action without agent) though there are overlaps but they are different in praxis and view essentially.  There is no need to forcefully integrate the various religions into one, that is just more attachment.

Although there is no monopoly over truth as ultimately all is/are talking about one's primordial nature but there are those that much clearer and precise in their system of practice.  If the views and philosophies are 90% inherent and dualistic, the result from such a system will at best be a stage to be achieved albeit the emphasis of “natural state”.

As I said before, if someone were to say "Soh is a malay, a speckie, used to be a c# programmer, 1.9m tall and has a sister", obviously some informations are correct and some are misleading.  Even if you were to stand right in front of him, he will not be able to recognize you.  Therefore although all are talking about the natural condition of pristine consciousness, some are exceptionally clearer than others.” – John Tan, 2020”