Zou Yan

Zou Yan was the representative thinker of the School of Yin-Yang during the Hundred Schools of Thought era in Chinese philosophy. Joseph Needham, a British sinologist, describes Zou as "The real founder of all Chinese scientific thought."

Zou Yan is commonly associated with Daoism and the origins of Chinese alchemy, going back to the Book of Han that calls him a ''fangshi'' . Holmes Welch proposes the ''fangshi'' were among those whom Sima Qian described as "unable to practice" Zou Yan's arts, and says while Zou "gradually acquired alchemistical stature, he himself knew nothing of the art. It was probably developed by those of his followers who became interested in physical experimentation with the Five Elements."