Our brain capacity is limited, and the objective and concrete world contains infinitely complex and numerous information. We must simplify the world to understand it. Therefore, all scientific theories can only be composed of abstract concepts and abstract theories.

Only abstraction can lead to prediction. For example, foreigners see that they can make money in Beijing, Shanghai and Shenzhen, so they abstract it and conclude that there is a high probability of making money in other place in China. This abstract understanding can produce scientific predictions to guide future investments. On the contrary, if we only stay in the specific individual things, no matter how accurate it is, it can not lead to scientific prediction. Without prediction, we can’t make decisions, and can’t seek benefits in practice.

Abstraction is the way of thinking that we must use, the colored glasses that we have to wear. The abstraction inevitably brings contradiction and dialectical logic. Because the objective world is concrete, the concept is abstract. An abstract concept can be related to many concrete things, and a concrete thing can be related to many concepts. For example, the concept of life is an abstract generalization of all living things, so life is related to many specific living things, such as people, eggs, trees, bacteria, etc. At the same time an egg can be related to countless concepts, such as hard, oval, white, crisp, calcium, life and nutrition. This kind of relation is called dialectical corresponding relation.

Figure 5. Dialectical Correspond Relation.

This kind of dialectical corresponding relation inevitably brings many contradictions. For example, ancient Chinese philosopher Gongsun Long said that a white horse is not a horse. Because a horse is an abstract concept, a white horse is a concrete horse, not an abstract concept.

A piece of paper has two sides, we call the top side as “A”, the bottom as “-A”. If the top side could go on forever, any part of it would be A. But for the Mobius strip, the top side and the bottom are connected. So top can be equal to bottom, A=-A. The inside of Klein bottle can be equal to the outside. At the poles of the earth, south can