Nirvikalpa, Savikalpa and Sahaja Samadhi. What’s the Difference?

Some books say nirvikalpa-samadhi is the best fame of mind to assimilate Self-Knowledge. Others argue it's savikalpa-samadhi. While Ramana Maharshi says it's sahaja-samadhi. Clarify please.

Nirvikalpa-Samadhi

Firstly, nirvikalpa-samadhi has two definitions:

1. Yogic definition (as explained in Patanjali Yoga Sutra):
   • This is the one we'll be describing below. Basically in the context, nirvikalpa samadhi refers to a state of deep meditative absorption where the mind becomes completely still, devoid of any mental modifications (vrittis). In this state, the practitioner experiences a profound silence and stillness, where the distinction between the observer (pramata, or subject) and the observed (prameya, or object) dissolves. The mind is free from all dualistic thoughts, and there is an experience of Self, untainted by any concept of having a body nor a mind, nor a life. Basically like deep sleep, but complete aware to the eternal truth that “I alone am”. This state is often considered the pinnacle of yogic practice, where the individual ego (sense of being an individual confined to the boundaries of the body and having a life story) temporarily dissolves, and the practitioner experiences a taste of the non-dual reality. However, it is important to note that in the yogic tradition, nirvikalpa samadhi is a temporary state. While it provides a profound experience of non-duality, it does not necessarily result in permanent liberation (moksha). The practitioner returns and once again is perturbed by sense of smallness or individuality.
   • Benefit: Nirvikalpa-samadhi can absolutely transform one's life in every positive imaginable way. Because all this time, you read about non-duality, and sort of related to it. But when it's tasted, it suddenly gives another layer of appreciation of what the scriptures are actually talking about. 
2. Advaita Vedanta definition: 
   • In the context of Advaita Vedanta, nirvikalpa carries a distinct and profound meaning. The term nirvikalpa is derived from the Sanskrit words “nir” (without) and “vikalpa” (differentiation or doubt). Thus, in Advaita Vedanta, nirvikalpa refers to a mode where the intellect (buddhi) is entirely free from any form of dualistic thinking or opposing thoughts regarding the nature of the Self (Atman). In this mode, the individual has attained a clear and unwavering understanding of their true nature as non-dual consciousness (Brahman). This understanding is not merely an intellectual conviction but a deep, and permanent recognition of Self as one who is free of all mental modifications (vrittis), this aging body, and this universe of forms. The intellect no longer entertains any opposing thoughts or doubts about the nature of “I.” This state of nirvikalpa in Advaita Vedanta is not a temporary meditative absorption, as it might be in the yogic context, but rather a continuous and spontaneous recognition of one's true nature.  In short, this is a jivanmukta (liberated or enlightened while living).

Answering Patanjali Yoga Sutras' Nirvikalpa-Samadhi…

Self-knowledge cannot be assimilated during nirvikalpa-samadhi because the buddhi (intellect) has basically resolved into a state of temporary dormancy within the causal body (karana-sharira).

Why can't self-knowledge be assimilated? Because intellect is all you have to discern or make sense of any experience. To extract insights and to assimilate them into permanent understandings that percolate through your entire being, in day-to-day living.

Furthermore, the buddhi is intwined with the memory (which is required to remember and contemplate later) and the ahamkara (I-sense) — the mechanism that localizes any learning to a single body-mind complex. 

Meaning when buddhi resolves, so does the memory and ahamkara resolve. Meaning, upon entry into nirvikalpa — the meditator hasn't remember nor understood anything, because there was no meditator or thinker or appreciator or learner (ahamkara) present in the nirvikalpa.

It's as good as a stranger having it, whose unable to pass on the benefits onto you (the meditator).

Moreover, during nirvikalpa, the intellect abides in a single, subtle, unmodified thought (“awake” to the anandamaya-kosha's bliss).

While this thought does offer a glimpse into our limitless nature — the mind perceiving it is in a state no different than dreamless sleep.

Though the “experience” of limitlessness is had — the knowledge is not consciously recognized, hence there's nothing valuable or long-term to take back into the ordinary waking experience that makes up majority of our life.

In short: The intellect is the instrument of knowledge, and thus if the intellect is not functioning, knowledge does not take place.

Savikalpa-Samadhi

In Savikalpa-samadhi — the intellect, memory and I-sense have not resolved into the causal-body.

They are available to the meditator (sense-of-I), thus the meditator is able to consciously appreciate one's nature — devoid of thoughts, of having a life, of having concerns. So there's still an identity of “I”, but that “I” is not referring to Brahman (your true nature), but to your sense-of-I (ego). Only difference is, that ego isn't listening to endless narratives of the mind of smallness, not-good-enough, being unlovable, being someone or nobody. 

In short:

Savikalpa-samadhi = Self (your true nature) still mistaking yourself for the ego (sense of being an individual), but that ego is devoid of any life story. 

Whereas normal waking state = Self (your true nature) still mistaking yourself for the ego (sense of being an individual), and on top of the ego, there is a life story that may or may not be pleasant.

Upon return to normal state — the meditator (ego) can further reflect, learn and transform one's life by the insights, since the entire experience was captured by the memory.

Savikalpa-samadhi can occur while one is transacting “business” with the world, but it is more likely to occur during sessions of formal or “seated” meditation.

Furthermore, Savikalpa-samadhi is the ideal platform for self-inquiry, and it was in a state of savikalpa-samadhi that ensued during Ramana Maharishi's near-death experience. It was a trigger summoning Ramana to begin questioning reality.

 

Sahaja-Samadhi

The term sahaja means “natural” or “effortless,”

Once the knowledge afforded through the experience of savikalpa-samadhi has been assimilated — then one is able to recognize and appreciate the underlying nirvikalpa (non-dual) nature of Awareness that is one’s true identity, even while engaged in one’s daily activities.

It is important to note that in Advaita Vedanta, sahaja samadhi is synonymous with the Advaitic definition of nirvikalpa samadhi as explained earlier. This is not to be confused with the yogic definition of nirvikalpa samadhi, which is often seen as a temporary state of deep meditative absorption. In the Advaitic sense, nirvikalpa samadhi refers to the continuous and effortless awareness of non-dual reality, which is precisely what sahaja samadhi embodies.