Xunzi (3rd century BCE) is the great Confucian counterweight to Mencius, and their disagreement over human nature is one of the classic debates of Chinese philosophy. Against Mencius, Xunzi held that human nature is bad, or, more precisely, that people are born with self-interested desires that, left to themselves, lead to conflict and disorder. Goodness is therefore not the flowering of an innate seed but a human achievement, the product of deliberate effort (wei).
The instruments of that achievement are ritual (li) and the accumulated wisdom of the sages: culture, education, music, ceremony and the moral order of society are the tools by which crooked human material is straightened, as a warped board is steamed and pressed into shape. Xunzi did not think people irredeemable, anyone, he insisted, could become a sage through study and practice, but he located morality firmly in cultivation and transformation rather than in nature. His is a demanding, this-worldly, deeply intellectual Confucianism that puts enormous weight on learning and on the civilising institutions of ritual.