Both nature and human society are restricted by the law of Yin and Yang. There are yin and yang in nature, which are interdependent and interact with each other. All yin and yang don't exist.

Human society is in nature, people are kind to beauty, people are kind to goodness, people want this world to be perfect and ugly, and people want this world to be intact and bad. This is only human rational imagination, this is only the goal that people pursue, and the ideal thing is only the direction to pursue, and it is not necessarily to be realized.

There is no all-good world, and there is no all-bad world. If there is a world full of goodness, all the evil words of human beings will disappear, and people's psychology and behavior towards evil will also disappear. People live a monotonous life without waves, and a completely good world is not a good world.

If human beings live in a world where everything is bad and nothing is good, then not only words and expressions with good words will disappear, but also the psychology and behavior of being good will disappear. People don't think it's delicious, and they don't even know who is delicious and who is not. It is impossible to know which dish is good or not. Things are different, things can be compared.

Good and bad are all compared. In the first 50 years, people compared the quality of straw houses. In the first 30 years, people were better than tile houses. Now people compare the quality of buildings, and the quality will always exist.