Human nature may be categorized as having three levels. This is a view of human nature held by ancient Chinese people. According to this theory, different people have different inherent natures, which can be divided into upper, middle and lower levels. People of the upper level have a good nature. People of the lower level have an evil nature. The nature of those in the middle level is either devoid of the distinction between good and evil, or is a mixture of good and evil. Some believe that human nature is inborn, particularly in those of the upper and lower levels, and is unchangeable. Others think that education can change human nature, allowing people to advance to the next level.

Mencius said that people were good by nature. I believe the people he referred to are those above the middle level. Xun Zi said that people were evil by nature. I believe the people he referred to are those below the middle level. Yang Xiong said that the nature of people was mixed with good and evil. I believe the people he referred to are those in the middle level. (Wang Chong: A Comparative Study of Different Schools of Learning)

Human nature can be divided into three levels, namely: upper, middle and lower levels. The nature of people in the upper level is innately good. The nature of people in the middle level can be guided towards good or evil. The nature of people in the lower level is innately evil. (Han Yu: An Inquiry into Intrinsic Nature)