In 522 B.C.（the 20th year of Zhaogong，Duke of the state of Lu），Confucius called himself"a man of accomplishment at the age of 30"（the Analects·Weizheng）.By now he had laid good foundations in the fields of learning，moral integrity and politics.According to the Records of the Historian，he also set up educational institutions for the common people and accepted a lot of disciples.Some of the disciples were quite famous such as Yan Lu，Zeng Dian and Zi Lu.While Jinggong，Duke of the state of Qi and Yanying were visiting the state of Lu，Jinggong asked Confucius why Mugong，Duke of the state of Qin，could assume hegemony.Confucius replied that he knew how to make proper use of personnel.（the Records of the Historian · Confucian Clan）