In order to reflect thought and feeling on another, man should observe the same rule as in voice and word. The louder a person speaks in an assembly the more attention he attracts, and all those present perforce give him a hearing. In the same way, if a Sufi sends forth the vibrations of his thought and feeling, they naturally strike with a great strength and power on any mind on which they happen to fail. As sweetness of voice has a winning power, so it is with tenderness of thought and feeling. Thought-vibrations to which the spoken word is added are double in strength, and with a physical effect this strength is trebled.