The Uses of Not
Thirty spokes meet In the hub. Where the wheel isn’t Is where it’s useful.
Hollowed out, clay makes a pot. Where the pot’s not is where it’s useful.
Cut doors and windows to make a room. Where the room isn’t, there’s room for you.
So the profit in what is is in the use of what isn’t.
Lao Tzu: Tao Te Ching: A Book about the Way and the Power of the Way
trans. Ursula K. LeGuin