Guan Zhong's being appointed as Prime Minister by Duke Huan of Qi can be understood in politico-economic, ethical, and cultural terms. Although serving two sovereigns was not approbated in the Spring and Autumn Period, Confucius thought that Guan Zhong had demonstrated his "benevolence (ren)". It is related to the period's interpretation of rites and propriety (li), faithfulness and sincerity (zongxin), and benevolence and righteousness (renyi). "Without an acquaintance with the rules of propriety" indicates the cultural difference between Hua and Yi. Faithfulness and sincerity (zongxin) solidifies the country and its people, and further protects rites and music (liyue); ruler-minister righteousness (yi) coordinates li, ren, and zongxin, and illuminates the ideal relationship between ruler and minister, in response to the perception of ethics and social expectations of the period.