The law of mutual change of quality is also called the law of quantitative change and qualitative change, and the law of transformation from quantitative change to qualitative change. It is a universal law of the development of nature, society and thinking, and it is also one of the three basic laws of materialist dialectics. Marxist philosophy lays the law of mutual change of quality on the basis of materialism, and makes a comprehensive and scientific exposition of its position and function. This law reveals that things develop due to internal contradictory movements. Quantitative change is the increase or decrease of the number of things, which is meaningless and non-fundamental change; Qualitative change is a change in the fundamental nature of things, a mutation and a leap. Quantitative change is the preparation for qualitative change, which opens the way for new quantitative change. Quantitative change beyond a certain limit will inevitably lead to qualitative change, so that the old qualitative change will be transformed into a new quality, and then a new quantitative change will begin on the basis of the new quality. When the new quantitative change exceeds a certain limit, it causes new qualitative change, and so on, pushing things forward.

Commodity is the product of the development of human social productive forces to a certain historical stage, and it is a labor product for exchange. Engels made a scientific summary of this: commodities are "private products first", but these private products will only become commodities if they are produced for consumption by others, that is, for social consumption; They enter the consumption of society through exchange. "

The definition of commodities in accounting is all kinds of commodities purchased or entrusted by commodity circulation enterprises, accepted and sold in storage. In the compulsory political book of People's Education Edition, the definition is the product of labor used for exchange. The basic attributes of commodities are value and use value. Value is the essential attribute of commodities, and use value is the natural attribute of commodities.

* * * Common prosperity means that all the people will eventually reach a well-fed living standard through hard work and mutual assistance, that is, universal prosperity on the basis of eliminating polarization and poverty. It is one of the important contents of Deng Xiaoping's Socialism with Chinese characteristics Theory. China is vast in territory and abundant in resources, and * * * is not rich at the same time, but some people and regions get rich first, and those who get rich first help them, and gradually realize the goal of * * *. * * * Common prosperity with others is the essential stipulation and goal of socialism, and it is also the fundamental principle of socialism in China.