There were two opposing views of development in the 19th century. A push performance degradation is based on the second law of thermodynamics system, it argues that, due to the dissipation of energy, the world tends to be weak, the universe tends to "heat death", the structure of the retreat, disorder tend to the maximum, the whole world over time and the process of dying; Another is based on Darwin's theory of evolution of the evolution of the concept system, it points out that social evolution is the result of the increasing division of species, the evolution and increased, structure complex and orderly, and constantly reinforced by functional evolution, all nature and human society are to develop more advanced, more orderly organization structure. Accounting earnings include only realized gains, and exclude unrealized gains and losses, the economic benefits will be enterprise's operating earnings and are favorable to the same treatment, regardless of whether they have been implemented. Thus, in general, accounting gains are less than economic gains, and the difference is mainly in the interest. Interest rates are an important tool for regulating monetary policy, and they are also used to control economic growth, such as investment, inflation and unemployment. Reasonable interest rate plays an important role in the economic leverage of social credit and interest rate. As hicks income concept did not specify what is called "equal wealth", and thus the income concept formed the basis of many debates concept, and the theory of accounting earnings, especially the capital preservation theory has a great influence. In accounting, people used to call "maintaining the same level of affluence" as capital preservation.