How did Hayashi Razan promote Zhu Xi’s Neo-Confucian ideas in Japan?

Hayashi Razan was instrumental in establishing the philosophy of the Chinese Neo-Confucian thinker Zhu Xi as the official doctrine of the Tokugawa shogunate. His promotion of these ideas occurred through several key channels:1

• Government Service and Tutoring: Beginning in 1607, Razan served the first four Tokugawa shoguns, acting as an advisor and tutoring them in Neo-Confucianism and history. He was deeply involved in drafting official diplomatic documents and formulating shogunal laws.12
• Institutionalization: In 1630, he founded a private academy in Edo (now Tokyo) with government support, which eventually became the official state school. This institution, led by his descendants, ensured the continuity of his teachings as the state-sanctioned ideology.1
• Ideological Justification: Razan utilized Neo-Confucianism to provide a moral and political framework for the Tokugawa regime. He emphasized loyalty (chū) and a rigid, hierarchical social order, arguing that the separation of the four classes was consistent with the "way of heaven" (tendō).12
• Intellectual Synthesis: He reinterpreted Shintō through a Neo-Confucian lens and used his historical writings to provide a philosophical justification for the legitimacy of the Tokugawa government, effectively countering the revolutionary ideas of the preceding era.12