Breath is audible and visible, and when a spiritual person, by spiritual exercises, strengthens and purifies the breath, it becomes more intelligible, as a light and a sound. Life and light, in truth, are one; the breath is the life, and it is the same breath which is light. Breath in fact is the light of all senses; the senses of sight, smell, taste, hearing and touch perceive all things by the light of the breath. When the breath is absent from the body, the body with all its perfect mechanism becomes useless. It is natural, therefore, that every sense must become powerful and keen if the breath be developed and purified.