Because one believes in oneself, one doesn't try to convince. Because one is content with oneself, one doesn't need others' approval. Because one accepts oneself, the whole world accepts him or her.
Sincere words are not fine; fine words are not sincere. Those who are skilled (in the Tao) do not dispute (about it); the disputatious are not skilled in it. Those who know (the Tao) are not extensively learned; the extensively learned do not know it.
Clay is molded to form a cup, But it is on its non-being that the utility of the cup depends. Doors and windows are cut out to make a room, But it is on its non-being that the utility of the room depends. Therefore turn being into advantage, and turn non-being into utility.