Existence-Knowledge-Peace (Sat-Chit-Anandam) is the nature of 'I Consciousness'. Existence is the 'Presence' (Sat), the knowledge about the presence is 'Chit'. Existence and Knowledge bring in 'Peace'. This 'I Consciousness' only, permeates through the waking, dream and deep sleep stages, and at the same time, stands aloof as 'Thureeya'. This 'I-Consciousness' is known as 'Witness'. This I-Consciousness also denotes 'God', 'Presence', 'Sat', and 'Bhodam'. IT is like a mirror reflecting the three stages of waking etc, without being affected by the reflection. In the waking and dream stages, we see multiplicity whereas in the deep sleep what is reflected is the absence of multiplicity. Even this absence is a reflection in Consciousness.
The inquisitive mind wonders whether there is a Reality beyond I- Consciousness. Further, the non-dualists are not satisfied with the status 'Witness'which is assigned to I-Consciousness, for the reason that the I-Consciousness, as a Witness, brings in a duality, of 'witness' and the 'witnessed'. So, they contemplated whether there is a non-dual Reality beyond I-Consciousness. As a result, they declared that "Brahman" is the Ultimate Reality which is neither sat nor asat, neither chit nor jadam, neither a witness nor witnessed, neither consciousness nor unconsciousness, which has no outside, no inside, which is beyond seen, and cannot be grasped by the intellect. The Ultimate Reality is non-dual 'BRAHMAN', 'Awareness', 'Infinite'.
When we 'talk' of 'Brahman', we actually bring down the same to the level of Consciousness. Brahman is Pure Silence - nay It is beyond that. Brahman is Light as such. I-Consciousness is the first expression of the Ultimate Reality. I-Consciousness appears as I AM, a 'sense of presence'. While 'I'-Consciousness reflects space, 'I AM' reflects space as well as form. From 'I AM' all concepts arise. 'I AM' is the Universe with Elements and Gunas. From 'I AM', "I am the individual" arise. Thus, It is the I- Consciousness that alone appears as 'I AM" and reflects as 'I am the individual".
Whatever said, so far, are concepts - mere concepts arisen from 'I AM'. Where ego (a delusion of independent existence with a sense of 'doership') reigns the individual, Brahman, God and the Universe look apart. Where the ego is not, only Brahman remains - a non-dual Truth. "Just as Brahman and God - (the I-Consciousness), are non-different, the ''I-Consciousness and 'I AM' (the Universe) are same. Similarly, 'I AM' and 'I AM the individual', have no difference. The Great Truth "Jeevo Brahmaiva na aparah" declared by Sri Sankara, may be remembered in this context.
To sum-up: The Ultimate Reality is Beyond "I"-Consciousness; I-Consciousness is the expression of the Ultimate Reality. 'I AM' (the Universe) is an appearance on the surface of 'I-Consciousness'. 'I am the individual' is a reflection of 'I AM' as well as 'I'; The ego (individuality) is delusion. The 'individual' has to shed the ego, to realise oneness with Brahman. - "Jeevo Brahmaiva na aparah".
