[p. 223] As social practice continues, things that give rise to man’s sense perceptions and impressions in the course of his practice are repeated many times; then a sudden change[3-302]takes place in the brain in the process of cognition, and concepts are formed. Concepts are no longer the phenomena, the separate aspects and the external relations of things; they grasp the essence, the totality and the internal relations of things. Between concepts and sense perceptions there is not only a quantitative but also a qualitative difference. Proceeding further, by means of judgement and inference one is able to draw theoretical conclusions.[3-303] The expression in San Guo Yan Yi, “Knit the brows and a stratagem comes to mind”, or in everyday language, “let me think it over”, refers to man’s use of concepts in the brain to form judgements and inferences. This is the rational stage of knowledge, otherwise known as its logical stage. This is the second stage of cognition. When the members of the observation group have collected various data, and what is more, have “thought them over”, they are able to arrive at the judgement that the “Communist Party’s policy of the National United Front Against Japan and cooperation between the Guomindang and the Communist Party is thorough, sincere and genuine”. Having made this judgement, they can, if they too are genuine about uniting to save the nation, go a step further and draw the following conclusion, “Cooperation between the Guomindang and the Communist Party can succeed”.[3-304] This stage of conception, judgement, and inference is the most[3-305] important stage in the entire process of knowing a thing.[3-306] The real task of knowing is not perceptual knowledge, but rational knowledge. The real task of knowing is, through perception, to arrive at thought, to arrive[3-307] at the comprehension of the internal contradictions of objective things, of their laws and of the internal relations between one process and another, of the internal relations between objective processes, that is, to arrive at theoretical[3-308] knowledge. To repeat, logical knowledge differs from perceptual knowledge in that perceptual knowledge pertains to the separate aspects, the phenomena and the external relations of things, whereas logical knowledge takes a big stride forward to reach the totality, the essence and the internal relations of things and discloses the inner contradictions in the surrounding world. Therefore, logical knowledge is capable of grasping the development of the surrounding world in its totality, in the internal relations of all its aspects.
