On the theory of human nature, Dong Zhongshu also changed the philosophical view of predecessors and put forward a unique and direct and practical theory of "three qualities of sex". He divided human nature into three categories, one of which was "the nature of saints". People with this kind of humanity are kind to life, and do not need the education and edification of the day after tomorrow. Only emperors and sages have it. He further pointed out that "Heaven" endowed the supreme rulers with "the nature of saints" and made them noble and pure, because they were responsible for educating and ruling the people. Obviously, consistent with his other theories, Dong Zhongshu's theory of human nature also serves to classify and strengthen imperial power.