Legge   11 
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.      Lau   11  Thirty spokes share one hub. 
Adapt the nothing therein to the purpose in hand, and you will have the use of the cart. 
Knead clay in order to make a vessel. 
Adapt the nothing therein to the purpose in hand, and you will have the use of the vessel. 
Cut out doors and windows in order to make a room. 
Adapt the nothing therein to the purpose in hand, and you will have the use of the room. Thus what we gain is Something, yet it is by virtue of Nothing that this can be put to use.      Feng/English   11 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 make it useful. 
Therefore benefit comes from what is there; 
Usefulness from what is not there.     Bill Porter (Red Pine)   11 Thirty spokes converge on a hub but it's the emptiness that makes a wheel work pots are fashioned from clay but it's the hollow that make a pot work
windows and doors are carved for a house but it's the spaces that make a house work
existence makes a thing useful but nonexistence makes it work     Jonathan Star   11 Wu is nothingness, emptiness, no-existence Thirty spokes of a wheel all join at at a common hub yet only the hole at the center allows the wheel to spin
Clay is molded to form a cup yet only the space within allows the cup to hold water
Walls are joined to make a room yet only by cutting out a door and a window can one enter the room and live there
Thus, when a thing has existence alone it is mere dead-weight
Only when it has wu, does it have life