However, yogis had worked with sound for thousands of years before any such researches were thought of or undertaken. The school of Mantra Yoga is concerned with this science. The one belief that started this was that vibration is creative and that the whole universe was produced by sound, by the Word; as it says in the Bible, first was sound and then was light. This contains the mystical thought that one may understand vibrations as spreading in two directions; when audible they become intelligible, and coming from the form of the Being they become visible. But even if the Word were neither audible nor visible it would have the capacity of being both. If our power of sight and hearing is not enough to help us it is because the reality is beyond and above the range of our sight and hearing, and therefore it is not intelligible to us; we are not aware of it. But if our sight and heating allowed us to hear and see it we would know that all life is vibration.