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