The mind operates to receive sensations, interpret and provide direction for action to the emotional nature, the vital and nervous being and the physical instrument. It does so within the limitations of its own fragmented and divided understanding and the reflected nature of its light. The spiritual reason, starting from a different standpoint that is in unity with the wider truth and oneness of all existence, also acts upon these lower members, but does so from this higher standpoint, thus raising up the action of the emotions, vital being and physical body.
Sri Aurobindo describes this action: “The spiritual reason takes also the emotions and psychic sensations, relates them to their spiritual equivalents and imparts to them the values of the higher consciousness and Ananda from which they derive and are its modifications in an inferior nature and it corrects their deformations. It takes similarly the movements of the vital being and consciousness and relates them to the movements and imparts to them the significances of the spiritual life of the self and its power of Tapas. It takes the physical consciousness, delivers it from its darkness and Tamas of inertia and makes it a responsive recipient and a sensitive instrument of the supramental light and power and Ananda. It deals with life and action and knowledge like the mental will and reason, but not starting from matter, life and sense and their data and relating to them through the idea the truth of higher things, but it starts on the contrary from truth of self and spirit and relates to that through a direct spiritual experience assuming all other experience as its forms and instruments the things of mind and soul and life and sense and matter. It commands a far vaster range than the ordinary embodied mind shut up in the prison of the physical senses and vaster too than the pure mentality, even when that is free in its own ranges and operates with the aid of the psychical mind and inner senses. And it has that power which the mental will and reason do not possess, because they are not truly self-determined and originally determinative of things, the power of transforming the whole being in all its parts into a harmonious instrument and manifestation of the spirit.”
Sri Aurobindo, The Synthesis of Yoga, Part Four: The Yoga of Self-Perfection, Chapter 21, The Gradations of the Supermind, pg. 791