The archetypal Neo-Confucian philosopher, Zhu Xi (1130–1200), worked out a compelling summation of Confucius’ humanistic ethics, centered on Ren (humaneness, humane) practice and cultivation. Faced with competing philosophies and religions, Zhu Xi strove to deepen and broaden Confucius’ ethics and core teaching of Ren. He drew on Zhou Dunyi’s “Explanation of the Diagram of the Supreme Polarity” to lay a naturalistic foundation for Confucius’ ethics, and on Zhang Zai’s “Western Inscription” to affirm the consanguinity between cosmos and humanity. He opened his “Treatise on Humanity” by linking Ren with the pervasive cosmic impulse to create, thus showing that the Way of Ren is not limited to the proper conduct of human affairs but springs from a pervasive beneficent creative impulse in the world. Zhu Xi also worked out a justification for Confucius’ Humanistic ethics centered on Ren cultivation and practice. This justification supports a sort of relational Humanistic ethics, the East Asian counterpart to Kant’s justification of an individual centered Humanistic ethics. Taken together, Zhu Xi’s mature comments and reflections on the formation of a moral exemplar (junzi) show that he, like Kant, set forth several conditions for the moral worth of ethical agency, decision, and action. For Kant, the moral agent must will to act from duty out of respect for reason (the Moral Law) which underlies the Golden Rule as the Categorical Imperative. Zhu Xi’s account is more practical and less theoretical than Kant’s. Zhu Xi’s aspiring moral exemplar undertakes his learning, cultivation, and practice in the spirit of reverence. Such reverence not only assures the concentration and seriousness of his dedication but purifies his mind-heart (xin) such that he becomes increasingly discerning of Heavenly pattern (tianli), which in turn sharpens his sense of appropriateness (yi). This deeper discernment also catalyzes his moral determination of will (zhuzai) to form within and to anchor his motivation to live by Ren, humanity. As Kant’s model incorporates the role of love and the Golden Rule, Zhu Xi’s centers on the cultivation of Ren and Confucius’ formulation of the Silver Rule, which are grounded in love and empathy. These teachings express a deeply emotional, relational, yet still rational form of Humanism that shows promise for a more salient Humanism by underscoring the unity of cosmos, nature, and humanity in a moral-ethical perspective.