本文探討羅爾斯對於多元社會政治共識的證成。羅爾斯主張在面對憲政核心爭議與基本正義問題時，講理的公民能夠擱置具爭議性的整全性學說，遵循公共理性的理念，根據同一套政治性正義觀所提供的政治價值與正義原則來解決爭議、凝聚共識、證成決策。不過，羅爾斯的公共理性論至少面臨「完備性」、「公平性」、「單一性」「公共性」四方面的質疑，針對這些挑戰，羅爾斯對其理論進行了三項主要修正：第一，以「寬觀點公共理性」與「包含式公共理性」補充「排除式公共理性」。第二，公共理性的內容是由一整套「自由主義政治性正義觀之族系」所給定，「作為公平的正義」也只是諸多合理的政治性正義觀之一。第三，羅爾斯承認公共理性的侷限，然而在必要時，得以「基於公共理性的投票」做出決策。根據這些修正，筆者認為羅爾斯的公共理性論能夠回應「完備性」、「公平性」、「單一性」三方面的挑戰，但是仍無法完全解決「完備性」的問題。因此在本文中，筆者試圖以「寬觀點公共理性」與「廣泛的反思均衡」證成「羅爾斯式審議理論」，以突破公共理性的限制。筆者認為，以公共審議詮釋公共理性，將有助於強化羅爾斯公共理性論的功能，也有助於多元社會中政治共識的證成。

This paper explores Rawls’s justification for political consensus in a pluralistic society. Rawls argues that although value diversity is the fact of a modern democratic society, reasonable citizens would follow a political conception of justice endorsed by the overlapping consensus between different kinds of comprehensive doctrines to resolve fundamental constitutional conflicts and conflicts about basic justice. However, his idea of public reason could be challenged from four aspects, namely completeness, fairness, uniqueness and publicity. Facing these criticisms, Rawls has revised his theory in three aspects. First, he supplemented his idea of exclusive view of public reason with an inclusive view of public reason and a wide view of public reason. Secondly, he argued that public reason is determined by a family of liberal political conceptions of justice, and fairness is just one of them. Finally, in accordance with the idea of public reason, he asserted that we can make a political decision by voting if it is necessary. By reviewing the challenges to and revisions of Rawls’s public reason theory, this paper argues that Rawlsian deliberative theory, justified by the wide view of public reason and the wide reflective equilibrium, could further amend Rawls’ revisions. It could enhance the capability of Rawls’s public reason theory and the justification of public consensus in a pluralistic society by interpreting public reason through public deliberation.