The practice of Yoga is not an exercise in philosophy or religion; rather, it is a work that seeks to effect a change in consciousness. Along the way, as the process unfolds, new experiences and perceptions take hold in the inner being of the seeker. While the realization may begin in the mind, eventually the repeated and habitual adjustment to the standpoint leads to something deeper, something that transforms the very inner nature of the conscious existence. The key step is to work at dissolving the ego-sense, thereby liberating the consciousness from its bondage to the fragmented and limited conscious existence of the human personality, so that it may widen and partake of the nature of the universal and transcendent aspects of existence.
Sri Aurobindo identifies the methodology: “In the path of Knowledge one attempts this abolition, negatively by a denial of the reality of the ego, positively by a constant fixing of the thought upon the idea of the One and the Infinite in itself or the One and Infinite everywhere. This, if persistently done changes in the end the mental outlook on oneself and the whole world and there is a kind of mental realisation; but afterwards by degrees or perhaps rapidly and imperatively and almost at the beginning the mental realisation deepens into spiritual experience–a realisation in the very substance of our being. More and more frequent conditions come of something indefinable and illimitable, a peace, a silence, a joy, a bliss beyond expression, a sense of absolute impersonal Power, a pure existence, a pure consciousness, an all-pervading Presence.”
This new state of consciousness eventually finishes the process of dissolving the ego-sense as it takes hold, repeats itself and becomes constant. During the process, there come experiences such as “…first a sudden sense of a cosmic consciousness, a casting of oneness into the universal; from that universality one can aspire more easily, aspire to the Transcendent. There is a pushing back and rending or a rushing down of the walls that imprisoned our conscious being; there is a loss of all sense of individuality and personality, of all placement in Space or Time or action and law of Nature; there is no longer an ego, a person definite and definable, but only consciousness, only existence, only peace and bliss; one becomes immortality, becomes eternity, becomes infinity. All that is left of the personal soul is a hymn of peace and freedom and bliss vibrating somewhere in the Eternal.”
Sri Aurobindo, The Synthesis of Yoga, Part Two: The Yoga of Integral Knowledge, Chapter 9, The Release from the Ego, pp. 347-349