Mo Zhai, the founder of the Mohist School, opposed the transcendental theory of "knowing things from birth" and advocated the theory of sensory experience as the source of knowledge and the standard of truth for knowledge. He said: "The reason why the world knows everything is and The way of non-existence must be based on the facts of the ears and eyes of the public, and the ritual of knowing existence and death." Mo Zhai proposed the "three tables" or "three methods" for judging the authenticity of speech, advocating that "the ancient sage" "The king's affairs" is historical experience, "the reality of the people's ears and eyes" is the direct experience of everyone, and "it is regarded as a criminal administration and the benefit of the country and the people" is the actual effect of social politics, as the criterion for testing the truth of knowledge. The basic tendency of Zhai's epistemological thought is materialism, but he one-sidedly exaggerates the role of sensory experience and ignores the role of rational thinking. He even believes in erroneous experiences and absurd rumors, and even falls into the superstition of ghost theory. .The later Mohist work "Mo Jing" inherited and developed the materialist tendency in Mo Zhai's epistemological thought, and made simple materialism on the nature of knowledge, the source of knowledge, the process of knowledge and the truth standard of knowledge. The interpretation of doctrine. "Mo Jing" clearly states: "Knowledge, connection"; "Zhi, knowledge, can describe things because they have known them"; it is believed that knowledge is the "knowledge material" and "knowledge material" that people use to "know". The imitation and reflection of foreign objects that occur due to contact with foreign objects. This is a simple reflection theory point of view. The "Mo Jing" overcomes the error of Mo Zhai's narrow empiricism to a certain extent. It not only attaches great importance to the sensory experience of the five senses, but also attaches great importance to the sensory experience of the five senses. The discerning thinking of "heart" initially connects perceptual knowledge and rational knowledge. "Mo Jing" puts forward the argument that "name and reality are coupled and combined", and takes "Zhixing" as the unity of motivation and effect. "To test whether the name and reality are consistent. Some philosophers in German classical philosophy have seen the one-sidedness of empiricism and rationalism, and tried to combine perceptual knowledge and rational knowledge. Kant said: "Thinking without content is empty. Intuition without concepts is blind, and knowledge can only be produced when they are combined." In Kant's view, scientific knowledge should be knowledge that can add new things and have universal necessity, and all knowledge must be expressed as judgment. Judgments that can give people new things are synthetic judgments, and judgments that can give people knowledge of universal necessity are analytical judgments (see analytical judgments and synthetic judgments). Although acquired synthetic judgments have new things, they do not have universal necessity; although a priori analytical judgments have universal Necessity, but nothing new. Only when comprehensive judgments and a priori judgments are combined to form a priori comprehensive judgments can we have scientific knowledge. In fact, Kant only used a compromise method to combine the rationalist and empiricist views, and did not truly Overcome their shortcomings. Kant regarded the process of obtaining scientific knowledge as the synthesis process of perceptual materials by the cognitive subject in the form of transcendental categories, emphasizing the active role of the subject in the cognitive process. However, because he regarded the cognitive form as a priori It is empirical, so the subject's initiative is developed abstractly. At the same time, Kant separated the connection between essence and phenomenon, limited knowledge to the phenomenal world, denied the identity of thinking and existence, and came to the erroneous conclusion that "things in themselves" are unknowable. .The epistemology of dialectical materialism is different from the intuitive reflection theory of metaphysical materialism. It believes that the unique reflection of people is not in the form of passive intuitive external objects of a single person, but in complex social relationships and active Realized on the basis of practical activities. The reflection process is closely related to the material and conceptual creation process. Dialectical materialist epistemology is based on the historical development of active social practical activities, and scientifically reveals the reflection forms and characteristics unique to people in society. The dialectics of the reflection process. It is an active revolutionary theory of reflection and a new stage in the development of materialist epistemology. Metaphysical materialism has four characteristics, which are also limitations: first: mechanical, which attributes all movements to mechanical movements. It attempts to explain all phenomena from the perspective of mechanics, and even regards humans and animals as machines governed by mechanical laws. Therefore, metaphysical materialism is also called mechanical materialism; second: metaphysics, which regards all things as isolated from each other. It does not develop and change in nature; third: intuitiveness, it lacks a practical point of view in its treatment of the world and understanding; fourth: incompleteness: it only adheres to materialism in the view of nature and does not adhere to the view of history. Then they fall into idealism and regard spirit as the decisive force for social development.