subjective idealism. When one of them develops itself without denying the other, it advances. When it opposes the extreme theory of the other, it progresses. When it goes into the extreme and wants to put the other side to death, it is reactionary.

The development of ontology of world philosophy is divided into three phases. Ancient philosophy is the stage of objective idealism and materialism. Subjective idealism is in the bud. Objective idealism and materialism are simultaneously produced and developed. They are indepen- dent and basically do not interfere with each other. Pythagoras, Parmenides, Plato, and Aristotle are all objective idealists.

Why were the ancient philosophers interested in studying the origin of the world? Because philosophers looked for the commonality of everything. We can deduce from common things to concrete things. Deduction requires a major premise (big premise). It requires a bigger premise to get this big premise. The biggest premise is called the origin. The origin of philosophy is not the source of the world. The source of the world is physics problem, the origin is philosophical problem, philosophy is the basis of science, they need laws of deductive relationship. 

This deductive process is a thought process from simple to complex. Because the material world is also a development process from simple to complex, much like a deductive process, so people study how to deduce from the material world, which becomes the study of the origin. People want to find one thing, and with it they can make everything else. At first, water, fire, earth and other materials were considered the origin. And then, elementary particles such as atoms and quarks were discovered. It is true that the universe was originally made up of only elementary particles, but these materials are not able to evolve into the world now. The difference between substances is structure. Structure determines function, which includes various forces and complex interactions. So the world evolves from simple to complex with both basic particles and structure.

Basic particle and structure are matter. But the search for the origin is not for the material source of the world, but the logical starting point. This logical starting point is the beginning of the conscious world, not the material world. Pythagoras noticed that abstract things such as numbers could reflect commonality of things, and later Plato invented the Idea, which then dominated philosophy. Although people wanted to find the origin of the objective world, and they don't know the origin is the logical starting point, but people need commonality and theory to support practice every day, so people felt that the abstract concept is more philosophical than atoms. An idea is a dead thing, Hegel makes it a