The Universality of Contradiction

Mao says that everything contains within itself its own particular contradiction. He notes that everything is interdependent and interconnected. Nothing can be separated from the whole, but each thing is distinct from every other thing via its particular contradiction. Every form of society, every form of ideology,. every form of struggle has its own particular contradictions. It's the particular contradictions in different objects of study, which differentiate branches of science. In mechanics, there is the contradiction between action and reaction, while in physics, the contradiction consists in positive and negative electricity.