In order to contract, It is necessary first to expand. In order to weaken, It is necessary first to strengthen. In order to destroy, It is first necessary to promote. In order to grasp, It is necessary first to give. This is called subtle light. The weak and the tender overcome the hard and the strong.
LaoziWe put thirty spokes to make a wheel: But it is on the hole in the center that the use of the cart hinges. We make a vessel from a lump of clay; But it is the empty space within the vessel that makes it useful. We make doors and windows for a room; But it is the empty spaces that make the room livable. Thus, while existence has advantages, It is the emptiness that makes it useful.
Laozi