Tracing back to the source, seeking truth from facts is the implementation of the pre-Qin Confucian concept of the mean (“Zhong Yong” in Chinese). The central word is “Zhong”, the initial meanings of the word “Zhong” are “inside” and “center”; the verb of the mean is “Yong”, the word “Zhong” also has the meaning of “cooperation” and “harmony”; When the term points to universal content, “Zhong” refers only to “real” or “honest”. The doctrine of the mean is to seek truth from facts. The historical source of the doctrine of the mean is the bow and arrow culture, and its modern form is the practical science culture. The essence of the concept of seeking truth from facts is “starting from reality” rather than “starting from the actual theory” or “starting from utility”. Otherwise, we will... return to the anti-moderation paradox of “the success or failure of the affair is all to moderation”.