The use of the usefulness (Chuang Tzu)

Source: Emmanuel Tronquois: Poésie chinoise antique

When Confucius visited Ch'u, Chieh Yu, the madman of Ch'u, wandered by his gate crying, "Phoenix, phoenix, how his virtue failed! The future you cannot wait for; the past you cannot pursue. When the world has the Way, the sage succeeds; when the world is without the Way, the sage survives. In times like the present, we do well to escape penalty. Good fortune is light as a feather, but nobody knows how to hold it up. Misfortune is heavy as the earth, but nobody knows how to stay out of its way. Leave off, leave off - this teaching men virtue! Dangerous, dangerous - to mark off the ground and run! Fool, fool - don't spoil my walking! I walk a crooked way - don't step on my feet. The mountain trees do themselves harm; the grease in the torch burns itself up. The cinnamon can be eaten and so it gets cut down; the lacquer tree can be used and so it gets hacked apart. All men know the use of the useful, but nobody knows the use of the useless!"

The Complete Works of Chuang Tzu, translated by Burton Watson. Chap.IV, 18.