Cheng Hao
Zhu Xi, Cheng Ho, and Cheng Yi perceived the Dao in the context of li (Principle) and t'ien li (the Principle of Heaven). Cheng Hao regarded the fundamental matter of li, and thus Dao, to be humaneness. Developing compassion, altruism, and other humane virtues is following of the Way. Cheng Yi followed this interpretation, elaborating on this perspective of Dao through teachings about yin-yang interactions, the cultivation and preservation of life; and the axiom of a morally just universe.