Sri Aurobindo
Letters on Yoga
5. Planes and Parts of the Being
The phrase “central being” in our yoga is usually applied to the portion of the Divine in us which supports all the rest and survives through death and birth. This central being has two forms – above, it is Jivatman, our true being, of which we become aware when the higher self-knowledge comes,– below, it is the psychic being which stands behind mind, body and life. The Jivatman is above the manifestation in life and presides over it; the psychic being stands behind the manifestation in life and supports it.
The natural attitude of the psychic being is to feel itself as the Child, the Son of God, the Bhakta; it is a portion of the 
Divine, one in essence, but in the dynamics of the manifestation there is always even in identity a difference. The Jivatman, on the contrary, lives in the essence and can merge itself in identity with the Divine; but it too, the moment it presides over the dynamics of the manifestation, knows itself as one centre of the multiple Divine, not as the Parameshwara. It is important to remember the distinction; for, otherwise, if there is the least vital egoism, one may begin to think of oneself as an Avatar or lose balance like Hridaya with Ramakrishna.
Current publication:
Sri Aurobindo. Letters on Yoga // SABCL.- Volume 22. (≈ 28 vol. of CWSA).- Pondicherry: Sri Aurobindo Ashram, 1971.- 502 p.
Other publications:
1. 9839.
Sri Aurobindo. Letters on Yoga. I // CWSA.- Volume 28. (≈ 22 vol. of SABCL).- Pondicherry: Sri Aurobindo Ashram, 2012.- 590 p.
2. 22965.
Sri Aurobindo. Lights on Yoga [: Extracts from letters] / Reprint April 1977; First Edition: 1935.– Pondicherry: Sri Aurobindo Ashram, 1977.– 104 p.