Previous studies which relate education for humanity to philosophy of Toegye and Yulgok have a common problem that connection between theory and practice are loose. To solve this problem, this study firstly tried to show the relation between Toegye s self-expression of principle and education for humanity as well as practices based on that relation. Secondly, this study strives to examine Yulgok s transforming the temperament and self cultivation methods. Thirdly, this study listed the current messages from two great philosophers to modern education for humanity. Toegye, by the theory of self-expression of principle, asserted that good human nature is the driving force of morality and ethical behavior. He also said that establishment of morality should be based on the principle of human nature. When it comes to the practice of education for humanity, however, he focused on the issue of temperament. And he suggested reserving Reverence(居敬) based on his own theory. Yulgok tried to cultivate himself by transforming the temperament. He argued that in his theory of behavior, temperament expresses itself and the principle follows. The result is emotion, and it leads to the will and behavior in sequence. He focused on the junction between emotion and will, trying to making the will sincere. Although there seems to be a contradiction between the theory of Toegye and that of Yulgok, they have common belief that education for humanity should be pursued in the perspective of temperament in practice. Reserving Reverence(居敬) and making the will sincere(誠意) both seek to transform the temperament in good way. In conclusion, to these philosophers, the ground of education for humanity is concerned with principle whereas methodology of that education is in relation with temperament.