Abstract: The motive of the existentialism of Sartre based on the theory of conciseness is to object the essentialism, the thought of “being with others” based on the existentialism is meaningful to object the traditional ethics; But the claim to build the ethics resulting from the existentialism is impossible for its metaphysical foundations which will necessarily result in paradox.

Key words: Existence, Mitsei, Existentialism, Ethics, Paradox, Praxis Philosophy

摘要： 萨特从“意识的意向性“出发建构的实存主义,具有反对本质主义的显赫动机;由实存主义出发得出“他人就是地狱”、自我与他人正相冲突的结论,也具有反对规范伦理学的典型意义;但以此出发构建一种伦理学的理论主张却是不可能实现的。根本原因在于:作为其理论基石的实存主义依然是一种形而上学的致思路径,以此为视点无法与具体的伦理经验相兼容,而且必然陷入悖谬。

关键词: 实存, 共在, 实存主义, 伦理学, 悖谬, 实践哲学