The consciousness is the true self and non-duality is pure nature of the consciousness. To capture the essence of non-dual reality, where witness and the witnessed are identical, it is only pure consciousness that by which its very nature is self-revealing and self-knowing.
True nature of the self is “without the three states”. It is the absence three states and presence of fullness of consciousness in its true form which allows for the clear recognition of the Self.
Consciousness is the true self and it is the Knower and the Known, the Seer and the Seen, without any duality. Self, being one without a second, is always self-knowing. There is no “other” for it to know. That is why it is refer to the Self as the natural. The reference to natural implies the non-dual nature of the Self.
While deep sleep is a state of complete unconsciousness. The true state is the state of full and complete consciousness. Deep sleep is still the state of ignorance. And a true state of consciousness is the state of self-awareness. In a very real and true sense the true state of the consciousness is the state of “deep awake”. The self is fully asleep to the world of perceptions and fully awake in its true nature, which is non-dual consciousness.
The true nature of consciousness cannot be understood without self-knowledge. But it is not impossible to understand it. People who speak about true nature of the self without the being aware of the fact that self is not physical can only speculate about its nature. Because such people are confused about nature of the self, their statements create confusion for others.
The three states can continue to exist and function after acquiring self-knowledge. But for Gnani all the three states are unrelated, because he has become one with the witnessing consciousness.
After Self-Realization, the duality is seen as existing but not separate from the Self. The Self knows itself even though the duality still exists. The duality exists as a condition that rises from the Self and then is absorbed back into it. It is due to the presence of the duality, (until it disappears by death), that Knowledge of the Self can be passed on by the Realized beings to others who seek such knowledge.