where nothing exists

“Thirty spokes share the hub of a wheel;
yet it is its center that makes it useful.

You can mould clay into a vessel;
yet, it is its emptiness that makes it useful.

Cut doors and windows from the walls of a house;
but the ultimate use of the house
will depend on that part where nothing exists.

Therefore, something is shaped into what is;
but its usefulness comes from what is not.”

—Tao Te Ching: Chapter 11

translation by Kari Hohne (2009) source