In the spirit of renunciation.
Thirty spokes together makes a wheel for a cart.
It is the empty space in the center which enables it to be used.
Mold clay into a vessel;
it is the emptiness within that creates the usefulness of the vessel.
Cut out doors and windows in a house;
it is the empty space inside that creates the usefulness of the home.
Thus, what we have may be something substantial,
But its usefulness lies in the unoccupied, empty space.
-Tao Te Ching