Sri Aurobindo
Letters on Yoga
5. Planes and Parts of the Being
Fragment ID: 337
See largest or earliest found fragment here
Sri Aurobindo — Unknown addressee
November 8, 1936
In the experience of yoga the self or being is in essence one with the Divine or at least it is a portion of the Divine and has all the divine potentialities. But in manifestation it takes two aspects, the Purusha and Prakriti, conscious being and Nature. In Nature here the Divine is veiled, and the individual being is subjected to Nature which acts here as the lower Prakriti, a force of Ignorance, Avidya. The Purusha in itself is divine, but exteriorised in the ignorance of Nature it is the individual apparent being imperfect with her imperfection. Thus the soul or psychic essence, which is the Purusha entering into the evolution and supporting it, carries in itself all the divine potentialities; but the individual psychic being which it puts forth as its representative assumes the imperfection of Nature and evolves in it till it has recovered its full psychic essence and united itself with the Self above of which the soul is the individual projection in the evolution. 
This duality in the being on all its planes – for it is true in different ways not only of the Self and the psychic but of the mental, vital and physical Purushas – has to be grasped and accepted before the experiences of the yoga can be fully understood.
The Being is one throughout, but on each plane of Nature, it is represented by a form of itself which is proper to that plane, the mental Purusha in the mental plane, the vital Purusha in the vital, the physical Purusha in the physical. The Taittiriya Upanishad speaks of two other planes of the being, the Knowledge or Truth plane and the Ananda plane, each with its Purusha, but although influences may come down from them, these are superconscient to the human mind and their nature is not yet organised here.
Current publication:
Sri Aurobindo. Letters on Yoga // SABCL.- Volume 22. (≈ 28 vol. of CWSA).- Pondicherry: Sri Aurobindo Ashram, 1971.- 502 p.
Other publications: