Thus spake the master of charcoal: "Tao never sleeps, but those with the Tao may." A novice said to the master,"There is a master who uses a magic device to monitor and maintain the temperature of his charcoal fire when the fire must burn overnight. He tells this magic device what temperature he wants, and the fire stays at that temperature until the charcoal is exhausted. Surely, this is not of the Tao?" The master replied, "Even masters need their sleep."