The mind, which is in the form of universe, is unreal because it is the "Seen", like a dream. The reality and existence of the soul, which is in the form of consciousness, the most fundamental substance of the mind, which is in the form of universe, cannot be questioned, for this truth is self-evident. The consciousness is the true self. In fact, the self does not need any proof.
The self is self-evident, and no one can deny its existence for it is the basis of all the three states. Everyone is conscious of the existence of his self and never thinks that it is in the form of consciousness.
To doubt the existence of the self would be a contradiction in terms because then one would doubt the existence of the very doubter who engages in doubt. The existence of the doubter itself is based on the consciousness. Thus he has to find the reality of his own existence.
Without the existence of the self, which is in the form of consciousness it is impossible for us to entertain the idea or even to be capable of refutation. Because the knowledge of the self is not established through the so-called means of right knowledge, it is self-established.
Thus, the very existence of understanding and its functions presuppose the intelligence known as the self, that is self-established, different from these functions and on which they depend.
Both the possibility of knowledge and the means of knowledge have relevance if there would be the self that is the source of all knowledge. Therefore, consciousness, which is the true self, is beyond all doubt, "for it is the essential nature of him who denies it. Therefore, it is the nature of the self, not its reality or existence, which is to be proved. The self must seek itself in order to find what it is, not that it is.
Consciousness pervades all the three states as their formless substance and witness. It is formless without any parts, without qualities, spotless, having no abilities like going and coming, etc., devoid of ideas of `me' and `mine' and also of desire, aversion and effort.
It possessing no organs like the intellect, etc., free from attributes. It is neither the breath nor the breather. It is untouched by the individual experiences of birth, life and death, which happens within the universe. The self, pervades all the three states. It is within the three states and it is the apart from the three states. It is apart because it is not and entity of identity within the three states.
Consciousness is the deathless, birthless, eternal and real substance in all the three states. It is the unchanging reality behind the changing mind, which is in the form of universe. It is pure consciousness and it not affected by time, space and causality. It is limitless and without a second. In order to understand the true nature of consciousness one must discriminate the formless witness from three states.