It is highly useful for the seeker to have at least a general idea of the various levels of consciousness and their relation to one another, so as to be able to recognise the path and the steps to be taken to bring about the integration of consciousness sought in the integral Yoga.
Sri Aurobindo generally describes this as an upper hemisphere consisting of Sat-Chit-Ananda, Existence, Consciousness-Force and Bliss, which the human mind cannot conceive of in any real way because it is so far outside our frame of reference and experience, and a lower hemisphere consisting of Body-Life-Mind, the levels with which we are intimately familiar and by which we are generally circumscribed by their ignorance and limitations. Between the two hemispheres lies an integrating consciousness, which Sri Aurobindo has called the Supermind. There are of course intermediate stages between the Mental and the Supramental level, and our highest flights of non-linear experience, which we call intuition, revelation, illumination, or inspiration are the first strivings of the being to escape the limits of the mental consciousness and begin to relate to and experience these intermediate levels of ascent toward the true supramental consciousness.
The supramental consciousness itself acts as the power that relates the pure Sat-Chit-Ananda of the higher hemisphere. It acts as something of a “step-down transformer” to distribute this pure higher consciousness into the limited and limiting forms of mind-life-body and set up an interaction between these limited forms that can progressively manifest the intention of the Divine. There is thus a descent of consciousness moderated and mediated by the Supermind. This supramental consciousness also acts as the bridge for the ascent of consciousness as it evolves out of the limiting forms of mind-life-body to rejoin the pure Divine Consciousness in a comprehensive way.
Sri Aurobindo explains: Proceeding from the level of absolute divine Existence …”there is a sort of golden corona of Light, Power, Bliss and Truth–a divine Truth-Consciousness as the ancient mystics called it, a Supermind, a Gnosis, with which this world of a lesser consciousness proceeding by Ignorance is in secret relation and which alone maintains it and prevents it from falling into a disintegrated chaos. The powers we are now satisfied to call gnosis, intuition or illumination are only fainter lights of which that is the full and flaming source, and between the highest human intelligence and it there lie many levels of ascending consciousness, highest mental or overmental, which we would have to conquer before we arrived there or could bring down its greatness and glory here. Yet, however difficult, that ascent, that victory is the destiny of the human spirit and that luminous descent or bringing down of the divine Truth is the inevitable term of the troubled evolution of the earth-nature; that intended consummation is its raison d’etre, our culminating state and the explanation of our terrestrial existence.”
He concludes: “it is only by the ascent and victory of the Soul here in the body that the disguises can fall away and the dynamis of the supreme Truth replace this tangled weft of half-truth that becomes creative error, this emergent Knowledge that is converted by its plunge into the inconscience of Matter and its slow partial return towards itself into an effective Ignorance.”
Sri Aurobindo, The Synthesis of Yoga, Part One: The Yoga of Divine Works, Chapter 11, The Master of the Work, pp. 242-243