Xun Zi was an ancient Chinese philosopher in the Confucian tradition who disagreed with Mencius about human nature, teaching instead that people need education, ritual, and effort to become good. He believed strong institutions and careful teaching were what shaped a person's character over time. Two of his students, Han Fei and Li Si, went on to become key architects of the Qin dynasty's government, which unified China for the first time. His practical, disciplined ideas influenced Chinese thought and government for centuries.