Sri Aurobindo
Letters on Yoga
5. Planes and Parts of the Being
Fragment ID: 372
The psychic being is the soul, the Purusha in the secret heart supporting by its presence the action of the mind, life and body. The vital is the prāṇamaya puruṣa spoken of in the Taittirīya Upaniṣad, the being behind the Force of Life; in its outer form in the Ignorance it generates the desire-soul which governs most men and which they mistake often for the real soul.
The Atman is the Self or Spirit that remains above, pure and stainless, unaffected by the stains of life, by desire and ego and ignorance. It is realised as the true being of the individual, but also more widely as the same being in all and as the Self in the cosmos; it has also a self-existence above the individual and cosmos and it is then called the Paramatma, the supreme Divine Being. This distinction has nothing to do with the distinction between the psychic and the vital: the vital being is not what is known as the Atman.
The vital as the desire-soul and desire-nature controls the consciousness to a large extent in most men, because men are governed by desire. But even in the surface human nature the 
proper ruler of the consciousness is the mental being, manomayaḥ puruṣaḥ prāṇa-śarīra-netā of the Upanishad. The psychic influences the consciousness from behind, but one has to go out of the ordinary consciousness into the inmost being to find it and make it the ruler of the consciousness as it should be. To do that is one of the principal aims of the yoga. The vital should be an instrument of the consciousness, not its ruler.
The vital being is not the I – the ego is mental, vital, physical. Ego implies the identification of our existence with outer self, the ignorance of our true self above and our psychic being within us.
In a certain sense the various Purushas or beings in us, psychic, mental, vital, physical are projections of the Atman, but that gets its full truth only when we get into our inner being and know the inner truth of ourselves. On the surface, in the Ignorance, it is the mental, vital, physical Prakriti that acts and the Purusha is disfigured, as it were, in the action of the Prakriti. It is not our true mental being, our true vital being, our true physical being even that we are aware of; these remain behind, veiled and silent. It is the mental, vital, physical ego that we take for our being until we get knowledge.
Current publication:
Sri Aurobindo. Letters on Yoga // SABCL.- Volume 22. (≈ 28 vol. of CWSA).- Pondicherry: Sri Aurobindo Ashram, 1971.- 502 p.
Other publications: