bell and food is dog's interpretation of the world.

Lower forms of animals can only establish simple conditioned reflex, advanced animals can establish complex conditioned reflex, that is, the connection between multiple phenomena and changes in interest. If the dog observes that changes in self-interest do not occur at the same time as the phenomenon A, but at the same time as the phenomenon A+B, then in the dog's nervous system, A+B will be linked to the change in the interest. This is the earliest analysis.

For example, A is a ringtone, B is a breeder, and food is only available when the ringtone and the breeder appear at the same time; if there is only a ringtone, no breeder (the ringtone may come from a visitor), there is no food, then in the nervous system of the dog, A+B will be contacted with food. If the dog continues to observe that the food does not always appear at the same time as A+B, but always at the same time as the phenomenon A+B+C, then A+B+C will be contacted with food. This is called further analysis. Induction is the process of establishing conditioned reflexes, analysis is the process of establishing complex conditioned reflexes.

A newborn child does not have any concepts and knowledge, but he will slowly learn knowledge. This learning process is the process of gradually establishing conditional reflexes. For example, when learning to use chopsticks, he will be praised for doing it right and be punished if he do something wrong. There is no essential difference between this process and that of training dogs. The process to establish conditioned reflex is to strengthen associations of thinking. New conditioned reflex generate new associations that associate new stimuli (including images, words and sounds, etc.) with decisions, just as dogs associate ringtones with saliva. It produces science and technology to combine weeding and harvesting. Human complex decision-making, judgment, theory and social practice do not seem to have similarities to conditional reflex. In fact, all of these are complex conditional reflex.

The Materialism believes “Human cognition is a reflection of man's objective world.” This statement does not discover the nature of cognition. The reflection of the cell phone in the mirror is totally different from the reflection of the cell phone in the human eyes. After seeing the mobile phone, people can associate and act, and can pick up the mobile phone, and the reflection of the mirror will not cause any association and operation. Wittgenstein believes that the meaning is to use.

The so-called understanding mainly refers to the association of thinking. When you are too close to a painting, you often don't understand what it is drawn. When you are far away, it's easy to understand. Because what you see closely cannot make you association. Sometimes when you hear a word, you will immediately nod your head, “I have heard of it.” Actually, you do not understand its precise meaning. For example, even if you do not know the definition of life, you can understand what life is because you can associate this word to many things. The more association, the deeper the understanding is. Generally when people say, “I do not understand”, he just means that he cannot associate. Every time you read a book, you will get a new understanding. This mainly means that every time some new association