Sri Aurobindo
Letters on Yoga
5. Planes and Parts of the Being
In physical mind there can be an action of intelligent reasoning 
and coordination which is a delegation from the Buddhi and would perhaps not be attributed to the Manas by the old psychology. Still the larger part of the action of physical mind corresponds to that of Manas, but it comprises also much of what we would attribute to vital mind and to the nervous being. It is a little difficult to equate this old nomenclature with that of this yoga, for the former takes the mixed action of the surface and tries to analyse it – while in this yoga what is mixed together on the surface gets separated and seen in the light of the deeper working behind which is hidden from the surface awareness. So we have to adopt a different classification.
The physical mind has first to open to the higher consciousness – its limitations are then removed and it admits what is supraphysical and begins to see things in harmony with the higher knowledge. It becomes an instrument for externalising that knowledge in the pragmatic perceptions and actions of the physical life. It sees things as they are and deals with them according to the larger Truth with an automatic rightness of perception and will and reaction to impacts.
Current publication:
Sri Aurobindo. Letters on Yoga // SABCL.- Volume 22. (≈ 28 vol. of CWSA).- Pondicherry: Sri Aurobindo Ashram, 1971.- 502 p.
Other publications:
1. 10073.
Sri Aurobindo. Letters on Yoga. I // CWSA.- Volume 28. (≈ 22 vol. of SABCL).- Pondicherry: Sri Aurobindo Ashram, 2012.- 590 p.