Then when we consider the mind, we find that breath has to do with mind also. The mystic knows that the breath which we perceive by exhaling and inhaling through the nostrils is not the essential breath, but only the result of a current which runs not only through the body, but also through all the planes of man's existence. That which the nostrils feel is the result of the activity of breath. Were it not so we could not explain how the mind, which is so much vaster and finer than the body, and is a separate element, can possibly exert an effect on the body, and the body on the mind.