Chapter 26, Part 7 - Chuang Tzu

Hui Tzu said to Chuang Tzu, "Your words are useless!"

Chuang Tzu said, "A man has to understand the useless before you can talk to him about the useful. The earth is certainly vast and broad, though a man uses no more of it than the area he puts his feet on. If, however, you were to dig away all the earth from around his feet until you reached the Yellow Springs, then would the man still be able to make use of it?"

"No, it would be useless," said Hui Tzu.

"It is obvious, then," said Chuang Tzu, "that the useless has its use."
~ Burton Watson translation via Terebess Asia Online ~

Go here to read the introductory post to the chapters of the Book of Chuang Tzu.