The forceful retention of breath used in the yoga of body control was found by Buddha to be most painful as well as exciting to the nervous system, and it was only when he sat under the tree where he attained Nirvana that he found and practised the superior method which harmonized well with his lofty aim. An exercise which is largely identical with the one practised by the Buddha has been given in The Secret Path and The Quest of the Overself. The essence of it consists in breathing as gently and slowly as possible as is consistent with comfort for a few minutes prior to the actual practice of meditation. Thus the taking in and giving out of the breath is brought under temporary control. During the operation, attention should be wholly directed towards it, so that the student is fully conscious of the entire breath movement and of nothing else. This exercise is particularly recommended to remove thoughts of depression, bitterness, and unhappiness. Its chief aim, however, is to help bring down the upspringing thought waves to a calm surface and thus merge the numerous separate thoughts in undifferentiated Thought. Students of the ultimate path can just as usefully practise it as a preliminary to their mental exercise and it will be just as valuable to them. Two points ought, however, to be added to the description given in those books: the first being the necessity of keeping the torso erect so as to help and not hinder the respiratory process, and the second being that the breathing is not to be done by raising and lowering the shoulders but by raising and lowering the diaphragm so that the muscular region affected lies between the stomach and the chest.
-- Notebooks Category 5: The Body > Chapter 6 : Breathing Exercises > # 25
