Breath is likened to water. The flowing of the breath is like the flowing of a stream. Inhalation and exhalation show ebb and flow. Parts of the earth which water does not touch remain barren; so the centers in the body, with all their intuitive, innate capacities, remain unproductive if the breath does not reach them. Besides, various diseases, in spite of all their apparent causes, often have one principal cause, and that is the lack of free flow of the breath. Many operations could be avoided and several diseases could be cured by the knowledge of the phenomena of breath.