Letters of Sri Aurobindo
Volume 1. 1933-34
Fragment ID: 16391
You asked, “What is the exact nature of this pressure?”
When I withdraw for concentration a pressure, sometimes very powerful and intense, is felt on the entire spinal cord. If the concentration is continued for a long time the back gets tired.
There is no need to concentrate on it, if it comes as a natural result of the general withdrawal and concentration. I suppose, it is simply that the effort brings a concentration in the centres of the vital and physical to share in the stillness which the will acting through the mind is trying to impose on the nature.