(1) On the issue of world unity, Marxist philosophy fundamentally opposes dualism and pluralism, and holds that there is only one origin in the world. Origin means that everything is made of it, and all things and phenomena originate from it at first and then return to it. On the issue of world unification, do everything have the same origin, essence or foundation? Different schools of philosophy have different answers: that everything in the world has a homologous philosophical view, that is, those who recognize the unity of the world are called monism; Dualism with two independent elements in the world (such as Descartes) denies the unity of the world; Pluralism recognizes that there are more than two primitive beings in the world. For example, the contemporary philosopher Popper put forward the theory of three worlds and denied the material unity of the world.

(2) Marxist philosophy and idealism are also fundamentally opposed, thinking that the world is material unity, not spiritual unity. Monism can be divided into materialism monism and idealism monism: the philosophical view that everything in the world is unified in matter is called materialism monism; On the contrary, the philosophical view that everything in the world is unified in spirit is idealism monism. Marxist philosophy adheres to materialism monism and opposes idealism monism.

(3) There are also differences between Marxist philosophy and mechanical materialism, which hold that the world is the unity of diversity and material movement. On the issue of world unification, Marxist philosophy and old materialist philosophy also have differences in principle; On the one hand, it is affirmed that all kinds of things and phenomena in the world are different manifestations of matter and its existing forms, and the real unity of the world lies in its materiality; On the other hand, it affirms that the unity of the material world is the unity of diversity, and all qualitatively different things and phenomena in the world are interrelated, moving, changing and developing.

Second, the proof of the principle of material unity in the world

(A) to rely on the long-term sustainable development of science to prove.

1, theoretical proof of the origin and evolution of celestial bodies;

Theoretical proof of biological origin and biological evolution; All celestial bodies in the universe are material objects that exist independently of human consciousness. They have their own history of formation and development and are by no means the product of God's will.

2. Theoretical proof of human origin and social development; Life is evolved from inanimate matter by chemical means, and it is not a mysterious thing.

3. The Theory of Human Origin and Social Development proves that human beings, as the "spirit of all things", were not created by God, but evolved from animals. The development of human society is driven by the basic social contradictions, in which the unity of productive forces and relations of production is the mode of production, which is the decisive force for social development.

In a word, the development of natural science has fully proved the basic principle that the world is unified in matter from all angles.

(2) It should be proved by the long-term and sustained development of philosophy.

1, philosophy should specifically ask this question; Whether the world is unified in substance or spirit or in God needs a clear answer. Dualism, skepticism and agnosticism deny or avoid this problem, which can only give idealism an opportunity. Marxist philosophy clearly answered this question.

2. Philosophy should think dialectically; We should dialectically think about the unity of the world from many aspects, such as one and many, abstract and concrete, * * and individuality, absolute and relative, infinite and limited, so as to avoid falling into metaphysical thinking.

3. Philosophy should make extensive philosophical argumentation on this issue; For example, Marxist philosophy demonstrates that material determines consciousness, social existence determines social will, and productivity and production relations determine superstructure. These all demonstrate the principle of material unity of the world from different angles.

In short, whether it is scientific proof or philosophical proof, it is a long-term development process, which is actually endless.