《道德經第十一章》

“The Doors of Obernewtyn” (c. 1999) by Donato Giancola

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。

Dao De jing Chapter Eleven — Alan B. Taplow 11 THE EMPTY

    While thirty spokes are the substance
    of the cartwheel,
    The empty space within the hub and between
    the spokes permits the wheel to be useful
    While clay is the substance of the vessel,
    The empty space within permits the vessel
    to be useful.
    While doors and windows are cut
    as the substance of the wall,
    The empty space within these enclosures
    permits them to be useful.
    Thus:
    Form is generated by what IS.
    Usefulness lies in what IS NOT.

Dao De jing Chapter Eleven — James Legge 11 (The use of what has no substantive existence)

The thirty spokes unite in the one nave; but it is on the empty space (for the axle), that the use of the wheel depends. Clay is fashioned into vessels; but it is on their empty hollowness, that their use depends. The door and windows are cut out (from the walls) to form an apartment; but it is on the empty space (within), that its use depends. Therefore, what has a (positive) existence serves for profitable adaptation, and what has not that for (actual) usefulness.

Dao De jing Chapter Eleven — Arthur Waley 11 

We put thirty spokes together and call it a wheel;

But it is on the space where there is nothing

That the usefulness of the wheel depends.

We turn clay to make a vessel;

But it is on the space where there is nothing

That the usefulness of the vessel depends.

We pierce doors and windows to make a house;

And it is in these spaces where there is nothing

That the usefulness of the house depends.

Therefore just as we take advantage of what is,

We should recognize the usefulness of what is not.