A vessel is formed from a lump of clay with care, however, it is the empty space within the vessel that makes it useful.
LaoziTherefore the Sage embraces Unity, and is a model for all under Heaven. He is free from self-display, therefore he shines forth; from self-assertion, therefore he is distinguished; from self-glorification, therefore he has merit; from self-exaltation, therefore he rises superior to all. Inasmuch as he does not strive, there is no one in the world who can strive with him.
Laozi