The Soul is indeed the supreme Self but due to its association with ignorance it finds itself under the bondage of the illusory duality, which is the sole cause of experiencing birth, life , death and the world as a reality .
Sage Sri, Sankara says: - VC-47 All the effects of ignorance, root and branch, are burnt down by the fire of knowledge, which arises from discrimination between these two—the Self and the not-Self.
Sage Sri, Sankara says: - VC-162- There is no liberation for a person of mere book-knowledge, howsoever well-read in the philosophy of Vedanta, so long as one does not give up the false identification with the body, sense-organs, etc., which are unreal.
The false identification of the Self with the non-Self is considered to be the root cause of the universe. When through deeper self-search this false identification removed, it is called liberation.
The soul, the innermost self is of the nature of the objectless awareness. This truth is self-existent and cannot be denied, for to deny one‘s self is to actually prove its existence! The experiential realization of this truth is the goal of the seeker of truth.
There is no difference between self-knowledge and self-realization, for to know the true self is to realize the true self is not the waking entity (ego) but the formless soul, which is present in the form of consciousness.
Since the ultimate goal of the seeker of truth is to attain liberation from experiencing the duality as reality. Through Self-Knowledge, leads to the liberating the soul, the innermost self from experiencing the form, time and space as reality.
Self-knowledge or Brahma Gnana or Atma Gnana has been explored since time immemorial attests to its perennial interest and universal value.
Long before Socrates’ injunction: - “Know Thyself”, Indian sages have been exploring for long the question of the truth of the man and his experience of the universe. Self-knowledge or Brahma Gnana or Atma Gnana is fundamental since all other knowledge is dependent upon this knowledge. It is important for one to know “what is truth” to realize “what is untruth”.
Without first knowing the true self, one can never understand truly where he stands in the cosmic scheme of things. Ignorance of the innermost self is seen as the root cause of experiencing the birth, life, death and the world as reality.
Due to ignorance of our true self and consequent lack of correct valuation of things, one is stuck with the illusory reality of the universe because they take it as real.
Without knowing the true self —the truth of one’s existence—one can never overcome the ignorance.
Advaita only means negation of duality. The soul, which is present in the form of consciousness, is ultimate truth or Brahman. The consciousness is the cause of the origin, maintenance, and withdrawal of the universe is Advaita (i.e. non-dual), it means that the consciousness transcends all conceptions, positive and negative. Nothing positive can ever be imagined or said about it.
The consciousness is existence absolute, awareness absolute. Existence absolute means that consciousness is not unreal or non-existent. And it is not unconsciousness. Nothing positive can be stated about consciousness.
In one of the Upanishads the disciple says to the Master: "Lord, tell me the nature of Atman". The Teacher remains silent. Again the question is asked, and again the answer is silence. By his silence the Teacher indicated that the nature of Atman is in inexplicable, indescribable and unimaginable.
The soul, the innermost self is the One without a second. There is not the least shadow of multiplicity in the soul, which is present in the form of consciousness."