What is the origin of "Five Elements Theory"? Who is its founder?

The emergence of the five elements theory is still an unsolved problem in academic circles, and the opposition of the three opinions is extremely obvious. Yi scholars believe that the emergence of the Five Elements Theory is likely to be synchronized with the Yin and Yang Theory. However, some historians believe that the founder of the Five Elements Theory is Mencius. For example, Fan Wenlan said in "A Brief History of China": "Mencius is the founder of the Five Elements Theory. Mencius must have a king in five hundred years, from Yaoshun to Tang for more than five hundred years ... from King Wen to Confucius for more than five hundred years ... and so on. Zou Yan, who was later than Mencius, expanded his Five Elements Sect and became a Yin and Yang Sect. " The theory of five elements was invented by Mencius, and there is no definite evidence. Fan Wenlan himself denied it. In the same book and article, he said: "Mozi does not believe in the five elements, and refutes the five-color dragon divination to determine good or bad luck." The theory of five elements has been very popular in the Eastern Zhou Dynasty, and it has been used a lot in Zou Yan. " Mencius was a native of Shandong during the Warring States period, and the theory of five elements was introduced from the Eastern Zhou Dynasty. Obviously, the five elements were not invented by Mencius. Some history books say that Yang Yang's Five Elements Theory was founded by Dong Zhongshu in Han Dynasty, which is even more wrong. Philosophers such as Wu Baihui and Wang Lian think: "The plain text of the five elements can be found in Shang Shu Hong Fan (it is said that it was written in the early years of the Western Zhou Dynasty, and it can be written in the Warring States according to recent tests). Five elements, one day water, two days fire, three Tian Mu, four days gold, five days earth; Moist, flaming, wooden bends, golden sun paintings, and soil loves crops. " See the influence of Yin-Yang and Five Elements Theory on China's traditional science). It can be seen that the origin of the five elements theory is still a mystery.