Legalism is a philosophical and political theory that emerged in ancient China during the Warring States period. It emphasizes strict adherence to laws and regulations as a means of maintaining order and control within society. Legalists believe that human nature is inherently selfish, and therefore, a strong, centralized authority is necessary to enforce rules and punish wrongdoings. The most notable proponent of Legalism was Han Feizi, a scholar who argued that rewards and punishments should be clearly defined to ensure compliance. Legalism played a significant role in the establishment of the Qin Dynasty, which implemented harsh laws to unify and strengthen the state.