《老子道德经(英译本)Lao Tze》第十二章 11. Tools· 李耳

Thirty spokes meet at a nave;

Because of the hole we may use the wheel.

Clay is moulded into a vessel;

Because of the hollow we may use the cup.

Walls are built around a hearth;

Because of the doors we may use the house.

Thus tools come from what exists,

But use from what does not.