In this paper, to clarify the significance of "putting oneself in another's shoes" in the context of morality, we examine the ethics of Hare, who places this act as a central subject in moral philosophy and argues minutely about it with respect to practical problems. Focusing especially on his study of "I," we demonstrate the originality of his theory and his critics' failure to grasp its significance and possibilities. On the other hand, we elucidate the fundamental problem inherent in the presupposition of his theory and the importance of perspectives such as "here" and "now" which he failed to address. Through these considerations, we aim to reveal the standpoints that enable us to comprehend more precisely the significance of "putting oneself in another's shoes."