Zhu Xi’s engagement with the Great Learning reshaped it from a relatively practical manual into a carefully ordered roadmap of moral and political life. By reorganizing the work into a concise “classic” and an extended commentary, and by distinguishing a main text from appended chapters, he clarified its internal architecture and made its movement from inner cultivation to outer order unmistakable. This re-editing also involved arranging the material so that the sequence of self-cultivation, family regulation, statecraft, and peace under Heaven appears as a coherent progression rather than a loosely connected set of teachings.

Within this new structure, Zhu Xi articulated what later came to be known as the “Three Guidelines” and “Eight Steps,” thereby turning the text into a systematic program of ethical and political practice. The Three Guidelines—manifesting luminous virtue, loving or renewing the people, and resting in the highest good—frame the overarching aims of the path. The Eight Steps then trace the concrete process: investigating things, extending knowledge, making intentions sincere, rectifying the mind, cultivating the person, regulating the family, ordering the state, and bringing peace to all under Heaven. This stepwise reading emphasizes that broad social harmony grows organically out of disciplined inner work.

Zhu Xi’s commentary is also marked by a distinct Neo-Confucian metaphysical and epistemological lens. He interprets “investigating things” as the investigation of the principles (li) inherent in all things and events, making careful inquiry into the world the starting point of moral development. In this view, inner sincerity and rectification of the mind are not merely psychological adjustments but ways of aligning oneself with universal moral principle. Moral cultivation thus becomes a process of discerning and embodying li through engagement with the natural and social world, rather than relying solely on spontaneous intuition.

By emphasizing investigation, rational understanding, and a gradual, ordered path, Zhu Xi presents self-cultivation as the indispensable root of sound governance. The Great Learning, under his hand, becomes a bridge between personal spiritual refinement and the ordering of family, state, and “all under Heaven,” insisting that political order cannot be separated from the moral clarity of those who govern. Elevating the text to the status of one of the Four Books and making it foundational for education and official examinations, he ensured that this interpretation became orthodox across East Asia, shaping how generations understood the intimate link between inner virtue and outer harmony.