Duke Huan of Qi
This "qiqi" alludes to the ancient "Xunzi" (28.1), where it was a symbolic warning against complacency. When Confucius visited the ancestral temple of Duke Huan of Qi, he saw a "vessel that inclined to one side", which the caretaker called a "you zuo zhi qi" 宥坐之器 "warning vessel that sat on the right". Confucius said: "I have heard of such a warning vessel; if empty, it inclines; if half full, it is upright, and if completely full, it overturns". After watching a demonstration of the vessel's operation, he sighed: "Alas! How indeed could there be complete fullness and no overturning!"