There have always been divergent opinions on what human naturerefers to. The elucidation of constitutionalism needs to revolve aroundthe theory of human nature, starting from people and then returning tothem. In terms of human nature theory, China and the West have differentunderstandings, and the foundation of human nature theory of good andevil nature also has different constraints on national constitutionalism. In thehistory of Chinese thought, the question of the good and evil of human natureoriginated from Mencius, and thereafter, the theory of good nature is oftenregarded as the foundation of authoritarian human nature theory. The theoryof evil in nature, as a systematic theory that emerged in the West and originatedfrom Christianity, is often regarded as the foundation of constitutional humannature theory, and these two views are also full of paradoxes.