the supermind is a Truth-Consciousness in which the Divine Reality, fully manifested, no longer works with the instrumentation of the Ignorance; a truth of status of being which is absolute becomes dynamic in a truth of energy and activity of the being
This passage identifies the supramental plane as the locus where Divine Reality manifests in its fullness, free from the distortions of Ignorance, making every finite act an expression of the Eternal.
, The Synthesis of Yoga, 1948thesis