Length and shortness create each other, from each other. The ideas of height and lowness arise from a contrast between the two. The musical notes of the scale become harmonious melodies and chords through the relation of one with another, and the spaces in between. Anything which is in front of, has something behind it. Therefore, the sage manages affairs without doing anything, and conveys his ideas and instructions without the use of speech. The Tao te Ching.