There is an inner being in man of which he is not usually conscious; he lives in a superficial consciousness which he calls himself and which is normally concerned with outer things; one is aware of the inner being either not at all or only as something behind from which feelings, ideas, impulses, imperatives etc. come occasionally into the outer. When one ceases to be mainly concerned with outer and surface things one can go more inside nearer to this inner being and become aware of things other than the ego and the outer nature. One can become aware of the inner being and live in it and get detached from the hold of outer things, dealing with them from an inner consciousness (felt as separate from the outer consciousness) according to an inner truth of the soul and spirit and no longer according to the demands of the outer Nature.
Ref: Letters on Yoga – III