Sri Aurobindo, The Life Divine, p.906
..."there is even a self of body of which, by standing back from the body and its demands and activities and entering into a silence of the physical consciousness watching the action of its energy, it is possible to become aware, a true and pure physical being, the Purusha. So too, by standing back from all these activities of nature successively or together, it becomes possible to realise one's inner being as the silent impersonal self, the witness Purusha. This will lead to a spiritual realisation and liberation, but will not necessarily bring about a transformation; for the Purusha, satisfied to be free and himself, may leave the nature, the Prakriti, to exhaust its accumulated impetus by an unsupported action, a mechanical continuance not renewed and reinforced or vivified and prolonged by his consent, and use this rejection as a means of withdrawing from all nature. The Purusha has to become not only the witness but the knower and source, the master of all the thought and action, and this can only be partially done so long as one remains on the mental level or has still to use the ordinary instrumentation of mind, life and body. A certain mastery can indeed be achieved, but mastery is not transformation; the change made by it cannot be sufficient to be integral: for that it is essential to get back, beyond mind–being, life–being, body–being, still more deeply inward to the psychic entity inmost and profoundest within us, –– or else to open to the superconscient highest domains. For this penetration into the luminous crypt of the soul one has to get through all the intervening vital stuff to the psychic centre within us, however long, tedious or difficult may be the process. The method of detachment from the insistence of all mental and vital and physical claims and calls and impulsions, a concentration in the heart, austerity, self–purification and rejection of the old mind–movements and life–movements, rejection of the ego of desire, rejection of false needs and false habits, are all useful aids to this difficult passage: but the strongest, most central way is to found all such or other methods on a self–offering and surrender of ourselves and of our parts of nature to the Divine Being, the Ishwara. A strict obedience to the wise and intuitive leading of a Guide is also normal and necessary for all but a few specially gifted seekers.
As the crust of the outer nature cracks, as the walls of inner separation break down, the inner light gets through, the inner fire burns in the heart, the substance of the nature and the stuff of consciousness refine to a greater subtlety and purity, and the deeper psychic experiences, those which are not solely of an inner mental or inner vital character, become possible in this subtler, purer, finer substance; the soul begins to unveil itself, the psychic personality reaches its full stature.
The soul, the psychic entity, then manifests itself as the central being which upholds mind and life and body and supports all the other powers and functions of the Spirit; it takes up its greater function as the guide and ruler of the nature. A guidance, a governance begins from within which exposes every movement to the light of Truth, repels what is false, obscure, opposed to the divine realisation: every region of the being, every nook and corner of it, every movement, formation, direction, inclination of thought, will, emotion, sensation, action, reaction, motive, disposition, propensity, desire, habit of the conscious or subconscious physical, even the most concealed, camouflaged, mute, recondite, is lighted up with the unerring psychic light, their confusions dissipated, their tangles disentangled, their obscurities, deceptions, self–deceptions precisely indicated and removed; all is purified, set right, the whole nature harmonised, modulated in the psychic key, put in spiritual order. This process may be rapid or tardy according to the amount of obscurity and resistance still left in the nature, but it goes on unfalteringly so long as it is not complete. As a final result the whole conscious being is made perfectly apt for spiritual experience of every kind, turned towards spiritual truth of thought, feeling, sense, action, tuned to the right responses, delivered from the darkness and stubbornness of the tamasic inertia, the turbidities and turbulences and impurities of the rajasic passion and restless unharmonised kinetism, the enlightened rigidities and sattwic limitations or poised balancements of constructed equilibrium which are the character of the Ignorance".
So this is what happens when the psychic being is able to move forward and become the ruler of our nature.