Thirty spokes share the wheel's hub,
It is the center hole that makes it useful.
Shape clay into a vessel,
It is the space within that makes it useful.
Cut doors and windows for a room,
It is the holes which makes it useful.
Therefore profit comes from what is there,
Usefulness from what is not there.
三十輻,共一轂,當其無,有車之用。
埏埴以為器,當其無,有器之用。
鑿戶牖以為室,當其無,有室之用。
故有之以為利,無之以為用。 」