Behind, within, and around the physical body there is another and invisible body which we may call the vital body. This is a kind of archetype or pattern for the physical body. On several points they coincide, but not on others. This subtler etheric body comes into existence before actual birth and remains for a while after actual death. During incarnation it is closely connected with the physical body and especially with its vitality, health, and sickness. The part of it which surrounds the physical body and which we may call the vital aura should not be confused with the other and larger aura wherein emotions and thoughts are reflected. During experiments which I made with a group of London physicians before the war, it was found that this vital aura extended for about forty-five centimetres beyond the physical body. When the vital aura was in a devitalized, fatigued condition, there was less resistance to sickness; but when it was energized the resistance increased. The life-force which we draw from the universal life-force enters into the vital body. Resistance can be increased by deep breathing, by exercise, and by imagining the life-force as a white light entering through the head and penetrating downwards into every cell of the physical body. This also helps the healing process in sickness. Not only are the cells permeated by these methods, but they are also purified.
-- Notebooks Category 10: Healing of the Self > Chapter 2: The Universal Life Force > # 27
-- Perspectives > Chapter 10: Healing of the Self > # 15