On the question on Chitta & Consciousness by a disciple Sri Aurobindo wrote a letter to him describing an analytical explanation on the subject as below:
You seem to want to reduce everything to a catalogue and a scientific analysis. Nobody has ever been able to do that with the working of the consciousness. The elements of a condition of consciousness cannot be classified like the “elements” of Matter.
Consciousness is not, to my experience, a phenomenon dependent on the reactions of personality to the forces of Nature and amounting to no more than a seeing or interpretation of these reactions. If that were so, then when the personality becomes silent and immobile and gives no reactions, as there would be no seeing or interpretative action, there would therefore be no consciousness. That contradicts some of the fundamental experiences of Yoga, e.g., a silent and immobile consciousness infinitely spread out, not dependent on the personality but impersonal and universal, not seeing and interpreting contacts but motionlessly self-aware, not dependent on the reactions, but persistent in itself even when no reactions take place. The subjective personality itself is only a formation of consciousness which is a power inherent, not in the activity of the temporary manifested personality, but in the being, the Self or Purusha.
Consciousness is a reality inherent in existence. It is there even when it is not active on the surface, but silent and immobile; it is there even when it is invisible on the surface, not reacting on outward things or sensible to them, but withdrawn and either active or inactive within; it is there even when it seems to us to be quite absent and the being to our view unconscious and inanimate.
Consciousness is not only power of awareness of self and things, it is or has also a dynamic and creative energy. It can determine its own reactions or abstain from reactions; it can not only answer to forces, but create or put out from itself forces. Consciousness is Chit but also Chit Shakti.
Consciousness is usually identified with mind, but mental consciousness is only the human range which no more exhausts all the possible ranges of consciousness than human sight exhausts all the gradations of colour or human hearing all the gradations of sound—for there is much above or below that is to man invisible and inaudible. So there are ranges of consciousness above and below the human range, with which the normal human has no contact and they seem to it unconscious, —supramental or overmental and submental ranges .
When Yajnavalkya says there is no consciousness in the Brahman state, he is speaking of consciousness as the human being knows it. The Brahman state is that of a supreme existence supremely aware of itself, svayamprakāśa,—it is Sachchidananda, Existence-Consciousness-Bliss. Even if it be spoken of as beyond that, parātparam, it does not mean that it is a state of Non-existence or Non-consciousness, but beyond even the highest spiritual substratum (the “foundation above” in the luminous paradox of the Rig Veda) of cosmic existence and consciousness. As it is evident from the description of Chinese Tao and the Buddhist Shunya that that is a Nothingness in which all is, so with the negation of consciousness here. Superconscient and subconscient are only relative terms; as we rise into the superconscient we see that it is a consciousness greater than the highest we yet have and therefore in our normal state inaccessible to us and, if we can go down into the subconscient, we find there a consciousness other than our own at its lowest mental limit and therefore ordinarily inaccessible to us. The Inconscient itself is only an involved state of consciousness which like the Tao or Shunya, though in a different way, contains all things suppressed within it so that under a pressure from above or within all can evolve out of it —“an inert Soul with a somnambulist Force”.
The gradations of consciousness are universal states not dependent on the outlook of the subjective personality; rather the outlook of the subjective personality is determined by the grade of consciousness in which it is organised according to its typal nature or its evolutionary stage.
It will be evident that by consciousness is meant something which is essentially the same throughout but variable in status, condition and operation, in which in some grades or conditions the activities we call consciousness can exist either in a suppressed or an unorganised or a differently organised state; while in other states some other activities may manifest which in us are suppressed, unorganised or latent or else are less perfectly manifested, less intensive, extended and powerful than in those higher grades above our highest mental limit.
Sri Aurobindo, Letters on Yoga, Vol I.