Pavlov-trained dog thought of food when it heard a bell, it thought yesterday's bell was the same as today's bell, and it didn't know that the bell that sounds the same might come from a different person, or the same person for a different purpose. If the bell is set to A, the animal will think that A always equals A. If this kind of thinking can make it eat enough every day, then it thinks it is the truth.
Man came from animals, and man's thinking came from animals' thinking. The way of thinking of animals is conditioned reflex, and the basic type of human thinking (the instinctive form of thinking) is also conditioned reflex. Since formal logic could solve most problems in life, this kind of conditioned reflex was reinforced and became a fixed thinking of people. Later, people found that some things did not conform to formal logic, and this way of thinking had to be modified, so dialectical logic was born. Objective relations contain contradictions. But formal logic is useful, it can reason, it can draw useful conclusions, so formal logic seems objective.
There are contradictions between objective things, which do not conform to formal logic. Therefore, dialectical logic negates the rules of formal logic and makes the sentences contain contradictions in order to conform to the characteristics of objective things.
Definition: Formal logic is the rules of rational relations between sentences that do not contain contradictions. Dialectical logic is the rules of rational relations that contains contradictions between sentences.
The objective world is composed of Wu, Shi, Dao, Li and relations. Wu is material, Shi is event, the movement and change of substances and relations. Li is Plato's idea, the commonness of material, and Dao is the law, the commonness of events and relations.[2] Compared with formal logic, dialectical logic is closer to Dao. In the subjective world there are Xin, Xing, Qing, Yi and thought products. Xin is thought, Xing is nature, interests and needs, Qing is mood, emotion and vision, Yi is manner, will and decision. Formal logic is not law, it is rules, and a rule is a decision.