Abstract: Lyotard’s call for witnessing “the differend” is an attempt to defend the right to debate and to prevent plaintiffs from being victimized by the denial of this right.To bear witness to “the differend” is to question and rewrite the rational principles of the Enlightenment,and not to accept the “consensus” of grand narratives based on the rational principles of the Enlightenment as the basis for the legitimization of knowledge.Lyotard,drawing on Kant’s critique of reason and Wittgenstein’s critique of language,has implemented a critique of grand narratives,hoisted the banner of “the differend”,and engaged in a heated debate with Habermas’ communication theory and Rorty’s consensus theory.In this paper,we intend to explore the philosophical politics of Lyotard’s witnessing of “the differend” and its theoretical gains and losses from the relationship between theory and practice,the differend and consensus,and philosophy and politics,and to emphasize the sense in which this theory is neither a postmodernist politics nor a “the differend” politics.Given that，in Lyotard’s view,“politics will always be only about the art of the possible”,what he calls witnessing “the differend” is also witnessing the possibility that the unexpressed can be expressed.