本文探討羅爾斯後期自由主義理論中，如何對現代多元社會的整合予以證成。羅爾 斯在《正義論》中，將正義原則立基於作為一種整全性學說的自由主義，在《政治自由主義》 中則予以重構，將其定位為一種獨立之政治的正義觀。據是，自由社會之整合並非基於特定 的整全性學說，而是各種整全性學說之交疊共識-亦即政治的正義觀。在交疊共識觀念之外， 羅爾斯提出公共理性觀念，據以探究政治的正義觀與各種整全性學說之間底複雜關係。本文 以為，儘管羅爾斯以政治地合理取代哲學地其理做為理論判準受到諸多批評，不過就解決現 代多元社會的整合難題而言，仍然是一個可行的進路。

　　　　　This paper explores Rawls's theory of social unity in a pluralistic society. I indicate that Rawls justifies social unity through recasting his early argument in A Theory of Justice. In Rawls's early argument, the principles of justice are based on liberalism as a comprehensive doctrine. But his later argument in Political Liberalism, they are presented as a freestanding view. From this viewpoint, a free society is not united in its basic moral beliefs but in its political conception of justice. Furthermore, Rawls regards the political conception of justice as the focus of an overlapping consensus of reasonable comprehensive doctrines. In addition to the idea of overlapping consensus, Rawls adopts the idea of public reason to explain the complex relationships between political conception of justice and various comprehensive doctrines. Despite of Rawls's theory of social unity is criticized by some scholars for his replacement of the philosophically true by the politically reasonable as the criterion of theoretical construction, I conclude that Rawlsian approach is feasible to solve the difficult problem of social unity in modem pluralistic society.