1. What is the concreteness and historicity of the unity of subject and object? 1. The concreteness of the unity of subjectivity and objectivity means that the coincidence of subjectivity and objectivity is realistic, not arbitrary and false. This unification is limited by specific conditions such as time and place. The reality of the unity of subject and object requires people to truly realize this unity, rather than replacing the objective reality with their own imagination. Analyze the historical conditions of realizing this unification in detail. Lenin clearly pointed out: "We do not deny the general principles, but we demand a special analysis of the specific application of these general conditions. Without abstract truth, truth is always concrete. " The unity of subjective and objective means that the subjective should be consistent with the objective reality, that is, we should proceed from reality and seek truth from facts. 2. The historicity of the unity of subjectivity and objectivity means that the unity of subjectivity and objectivity is changing and developing, not static. This unity changes with the movement of the objective material world, and it is the unity in the process of change and development, not static or dead. Lenin once pointed out that the consistency of thought and object is a process, and thought should not think that truth is dead and static. It is like an elf, a figure or an abstract thought, with no trend, no movement and no light.