( 1724~ 1777)
Textual research scholar and thinker in Qing dynasty. The word Dongyuan was born in Long Fu, Xiuning, Anhui (now Tunxi). Jinshi, a former editor of the Hanlin Academy, Jishi Shu. Philosophically, he believes that the material qi is the origin of the universe, and the yin and yang, the five elements and the Tao are all material qi. It is believed that reason is the order and law of things, and it cannot exist without concrete things. Reason lies in things and is "materialized gas". He also believes that the universe is a general process of gasification and popularization, "heaven and earth gasification and popularization, endless." In epistemology, he believes that human cognitive ability is "the change of heaven and earth". Through the contact with foreign objects, the mind can discover the laws of foreign objects, and knowing things is to investigate and study things. Only through observation and analysis can we know the truth of the matter.
He also put forward the theory of "illumination", thinking that the understanding of the mind is like a fire illuminating things, illuminating near and illuminating far, which is essentially a simple and intuitive reflection theory. In ethics, it is considered that human's "desire, emotion and knowledge" are human nature. To deny lust is to deny being human. He advocates distinguishing between desire and private, and thinks that private is "the loss of desire" and cannot "blame desire on private". It is necessary to "preserve reason and restrain desire" so that people's natural lust can be reasonably satisfied, not just "preserve reason and restrain desire". He also put forward the idea of "washing feelings with feelings" and opposed the hypocrisy of Taoism and "killing people with reason". He wrote a lot in his life, including mathematics, astronomy, geography, phonology, exegetics, textual research, philosophy and many other aspects. There are Collected Works of Dai Zhen (Zhonghua Book Company Edition, 1980) and Dai Zhen Ji (Shanghai Ancient Books Publishing House Edition, 1980).