2022 年 71 巻 p. 145-158
The aim of this study is to clarify the essence and meaning of the duality of human existence that Karl Löwith often refers to in his book The Individual in the Role of Fellow Man（1928）. Löwith regards the structure of human existence as the equal and fundamental unity of “personality” and “naturality.” First, this dual structure of human existence is superimposed on the duality of rational beings（person as a selfpurpose and thing as a means to an end）in Kant’s practical philosophy; then Löwith attempts to reinterpret Kant’s practical philosophy based on the principle of being-with-others. However, in his theory of being-with-others, Löwith recognizes the positive meaning of human naturality, which does not limit character to a thing of a person in Kant’s practical philosophy. This positive meaning is a potential basis for mutual understanding in dialogue with others. Involuntary communication based on human naturality brings more of human nature into expression than voluntary communication through words. It also builds appropriate dialogical relationships. By defining human personality not merely as self-purposiveness, but also as responsiveness to others, the construction of personality based on dialogical relations becomes essential for human beings. This inevitably leads to the evaluation of human naturality, which is the basis of mutual understanding ─having positive value. In addition, Löwith mentions that the fact that we have a dual structure of existence in itself makes human life possible. In other words, human beings are, by their very nature, conflicted beings with a dual structure; this makes it possible for them to question their own life. Löwith’s theory of being-with-others, which emphasizes the meaning of human naturality in dialogue, is significant as an attempt to overcome modern Western philosophy, which places value only on personality（autonomous ability）.