.Self -knowledge or Brahma Gnana or Atma Gnana is the end of the egocentric knowledge.

There is no man but mind. There is no world but mind.   There is no God but mind.  There is no waking but mind. Whole physical existence is nothing but mind. Mind mere illusion created out of soul or consciousness.  

The world is myth. Waking is myth. Mind is myth.  But the formless substance and witness of the mind or universe or waking is real and eternal. The formless substance and witness are one in essence and that essence is consciousness. The formless consciousness is the innermost self and it is ultimate truth or Brahman.   The soul as illusion is mind. The formless substance of the illusion is soul.  

Self -knowledge  or Brahma Gnana or Atma Gnana is the end of the egocentric knowledge. egocentric knowledge  is based on the waking entity ,which is false self within the false experience(waking). Self-knowledge or Brahma Gnana or Atma Gnana is universal knowledge.  self-knowledge is soul-centric knowledge which leads to  awareness of beginning -less existence. 

Orthodox non-duality is nothing more than set of beliefs and dogmas based on the ego or waking entity. orthodox non-dualist's blindly accept scriptures  as yardstick and there is no scope for inquiry whereas :

 

Sri, Sankara says in (VC) indicated that:-

 

56. Neither by Yoga, nor by Sankhya, nor by work, nor by learning, but by the realisation of one's identity with Brahman is Liberation possible, and by no other means. 

58. Loud speech consisting of a shower of words, the skill in expounding the Scriptures, and likewise erudition - these merely bring on a little personal enjoyment to the scholar, but are no good for Liberation.

59. The study of the Scriptures is useless so long as the highest Truth is unknown, and it is equally useless when the highest Truth has already been known.

60. The Scriptures consisting of many words are a dense forest which merely causes the mind to ramble. Hence men of wisdom should earnestly set about knowing the true nature of the Self.

61. For one who has been bitten by the serpent of Ignorance, the only remedy is the knowledge of Brahman. Of what avail are the Vedas and (other) Scriptures, Mantras (sacred formulae) and medicines to such a one?

Buddhism:-

Empty and calm and devoid of self Is the nature of all things. No individual being In reality exists. There is no end or beginning, Nor any middle course. All is an illusion, As in a vision or a dream. All beings in the world Are beyond the realm of words. Their ultimate nature, pure and true, Is like the infinity of space.

- Prajnaparamita

This Empty and calm and devoid of ‘I’ is the nature of the Self. The individual being or non being exists in reality. There is no end or beginning, nor any middle course. The diversity is an illusion or a dream. The formless substance and witness of the diversity, which is the Consciousness  or Christ  or Self  or Brahman or formless Buddha is beyond the realm of words. The ultimate nature of the experience of diversity is, pure and true, is like the infinity of space, which is God, Christ, Brahman.

2

If ‘Self’ is neither the physical body nor the ego, then  'Self' is without the body and without the ego.  If self is without the body and without the ego means it is without the world because the body, ego and the world they appear together as waking or dream and disappear together as deep sleep.  Therefore 'self is formless  Therefore, the self is nothing to do with the waking entity and waking world because it is ever formless.  Therefore,  one has to find out  what is that appears as waking and what is that appears as dream and what is it that disappears as deep sleep instead of inquiring WHO AM ‘I’? , which is limited only to the waking entity and waking experience.   Without inquiring into the nature of the all the three states the truth will be unfolded because the consciousness is not limited to waking experience alone but it pervades all the three states.  

Since the sense of ‘I’ is present only when the mind (universe or waking or dream) is present and it disappears along with mind. The seeker will come to conclusion after thoroughly verifying this fact through deeper self-search and then come to firm conviction that ‘I’ is mind and mind is universe and universe appears as waking or dream.  This ‘I’ is not the self. Holding ‘I’ as self is erroneous because ‘I’ (mind or universe or waking) is mere illusion.  

If one has understood what ‘truth ‘really is “than there is no necessity to know ‘Who am I? or ‘I am that’.   ‘WHO AM I?’ or ‘I AM THAT’ reveal only half-truth because they are limited to individuality and reveals only the unreal nature of the ego.   Ego is individuality whereas the self is not an individual because self is formless consciousness.  Thus the journey is incomplete.  Seeker has to go much deeper know the full truth about the ‘self ‘which is beyond form, time and space. 

The bookish knowledge is not wisdom. The knowledge accumulated from intellectual spoon feeding from the intellectual wise men is not wisdom.  The persons who are propagating only half-truth as absolute truth are playing with feelings of the seeker with ornamental words.   The people who are stuck with half-truth think they have already realized and think that they are realized truth and they try to snub others and expect to follow their own terms without realizing they have not yet completed the journey.