Who is Yu Qingji? What is the year of birth and death?

A famous Japanese sinologist in the 20th century, a professor at Nagoya University, whose date of birth and death is unknown, is the second generation scholar of Kyoto School, who inherited and developed Naito's theory of Hunan.

Yu Qing Ji tried to establish a new theory to further explain the history of China. He explained the law of China's historical development from the perspective of spiritual history. He believes that the times, like people, all have their own personalities, and the "style of the times" is not only the inheritance of the previous era, but also the characteristics of the times. He believed that the development of China society belonged to the ancient times before Qin and Han Dynasties, the Three Kingdoms was the beginning of the Middle Ages, and the ancient times ended in the late Han Dynasty.

He used the word "self-discipline" to express the epoch-making style of the Six Dynasties in the field of oriental medieval history. He defined the times style of Qin and Han Dynasties as "politics" and the times style of Six Dynasties as "self-discipline". He believed that Sui and Tang Dynasties were not only the development of the Six Dynasties, but also tended to return to Qin and Han Dynasties, which was a combination of "politics" and "self-discipline". The so-called "self-discipline" means that the opportunity to exist and exercise is hidden in it. Yu Qing Ji pointed out that China's medieval period began in Qin and Han Dynasties and ended in Sui and Tang Dynasties, and the most distinctive character in the Middle Ages was the "self-discipline" of the Six Dynasties, which was embodied by the aristocratic class. In this sense, the nobles of the Six Dynasties were different from the "political" operation centered on imperial power, and were based on independent authority.

He is the author of Fields in the History of the Middle Ages in the East and Oriental Light 2, 1947. Later, his Study on Social and Economic History of Han Dynasty was published in Hong Wen Hall.