Scholars from Tang Dynasty to Qing Dynasty generally evaluated Liu Yuxi as a writer. When talking about Liu Yuxi, Zhang Taiyan, a modern bourgeois democratic revolutionist and theorist, only said that "Liu Yuxi's Biography" (edited by Bian and Wu Ruyu, Shanghai Ancient Books Publishing House, 1980 edition, p. 38) in the Tang Dynasty did not involve his philosophical thoughts. Liu and Liu are rarely mentioned in China's works on the history of philosophy and thought since the May 4th Movement. It was not until the founding of New China that it gradually changed. Historically, Liu Yuxi played an important role in the history of ancient philosophy in China. On the basis of Xun Kuang's thought of "dividing people into tomorrow" and "controlling the destiny and using it", his theory of heaven put forward new ideas of "Heaven and man win each other" and "Man is obedient to heaven". He inherited Wang Chong's materialistic monism of qi, and expounded the idea that everything is transformed by qi, with ceaseless as the body and innovation as the Tao. Nothing can be "detached" and "overpowered", and both "number" and "potential" are attached to things ",which reflects that he has a deeper understanding of the regularity and inevitability of objective things than his predecessors and overcomes the limitations of Wang Chong and Fan Zhen's theory of accidental meeting. His materialistic explanation of "emptiness" and "nothingness" is an important contribution to the development history of China's materialistic thought. It is also better than the previous ones in the root analysis of the theory of destiny and the understanding of human characteristics. Lenin said: "The merits and demerits of history are not judged by the fact that historical activists have not provided what modern times require, but by the fact that they have provided something newer than their predecessors. "According to this principle to judge Liu Yuxi, it should be said that he made an important contribution to the development of ancient materialism in China, surpassing Xun Kuang, Wang Chong and Fan Zhen on some issues. To evaluate Liu Yuxi's philosophical thought, we can't help but involve his attitude towards Buddhism. Liu Yuxi's Buddhist thought is contradictory. He did not openly oppose Buddhism, but from the viewpoint of spontaneous materialism, he criticized the wrong view of ontology in Buddhist theory. He doesn't agree with the Buddhist saying that "Wukong leaves the phase, cherishes the emptiness and envies the existence", and says, "How can you realize nothing if you can't help yourself?" (Xinta, the first master of Zurong in Niutoushan) He also holds a negative attitude towards the "III" theory advocated by Buddhism. He said: "Sometimes, there are points after junior high school. In the sky, it is called yesterday and today. Physically, it has a period of youth and strength. Even if it is a voice, a ring, both Chinese and foreign, why ask for three different lives? " In Liu Yuxi's view, "Three" is an illusory thing and not worth pursuing. On the other hand, Liu Yuxi also spoke a lot of praise for Buddhism and Buddhists. As far as its content is concerned, it is mainly the idea of goodness and karma, such as "Buddha saves all sufferings with great compassion and broadens karma" (Mt.Yangqi Scenic Resort Monument in Pingxiang County, Aizhou) and "Gao Jie Wises Fire and Cleverly melts Jaken". Widen the toilet door and bypass the evil road. "("Farewell to the Prime Minister and Report to the Master ") These are undoubtedly wrong. When talking about the social function of Confucianism, Buddhism and Taoism, Liu Yuxi said, "Confucianism subdues the masses with the middle way" and "Buddhism saves all sufferings with great compassion", which means "taste is the same as morality" and "success is the same". Buddhism is a "yin education supplement", and "changing one's mind is between ignorance and ignorance, and losing love is between life and death ... beyond life and death, there is no cultivation, punishment is not as good as politics, and Song is gentle." This shows that Buddhism plays a special role in maintaining and consolidating feudal rule. Liu Yuxi's worship of Buddhism is not only the political need of the landlord class, but also the reflection of his thought. At the same time, Liu Yuxi approached the southern Sect of Zen Buddhism, introduced Confucianism into Buddhism, reformed Buddhist theory, advocated that everyone has the nature of becoming a Buddha, and adapted to the landlord in cloth clothes, opposing the requirements of privileged families. These are probably the political reasons why Liu Yuxi served the Buddha and the Buddha. Liu Yuxi relied on talent, but his career was bumpy and he was repeatedly hit. The social status of the landlord class made him see no other way out. So he turned to Buddhism to find spiritual sustenance and kill his will. He told himself the reason why he was close to Buddhism, saying, "Although there is no definite worry and joy in the world, there is a good reason for killing Shi." (Qiu Zhai sits alone and sends happiness to the doctor) However, just because Liu Yuxi really added some new contents to China's philosophy, we can't deny his position in the history of China's philosophy.