哈贝马斯对法政治学的一个重要贡献是阐释现代社会中法律的合法性来源和危机问题。在他看来,法律不能离开道德正确性问题,亦即合法性问题。在哈贝马斯的行动主义社会理论中,合法性是正当程序下主体间“理性辩论”这样的政治过程的可能结果;也就是说,只要主体间的交流、讨论、争论、谈判、协商和达成一致符合“理性的辩论伦理”,现代社会中法律的合法性是可以重塑和再塑的。换句话说,合法性成了程序的可能结果。哈贝马斯的这个“辩论伦理学”是建立在他的宏大的社会理论基础上的。本文的重点就是要在他的“交往行动理论”的框架内,围绕他关于法律的合法性问题,剖析他对法政治学(民主理论)的贡献及不足。 One important contribution Habermas made to law and political science is to explain the source of lawfulness and crisis in modern society. In his view, the law can not leave the question of moral correctness, that is, the issue of legality. In Habermas’s activist theory of society, legitimacy is the likely result of a political process such as “rational debate” among subjects under due process; that is, as long as the communication, discussion, debate, negotiation, negotiation and Agreement is reached in line with “rational ethics of debate,” and the legitimacy of law in modern societies can be reshaped and remodeled. In other words, legitimacy is a possible result of the procedure. Habermas’s “ethics of debate” is based on his ambitious social theory. The main point of this essay is to analyze his contribution and deficiency of law and political science (democratic theory) in the framework of his “theory of communicative action” and around his question about the legality of law.