大同主義者對羅爾斯「以民族為中心」的全球正義理論普遍感到 不滿，他們認為全球正義的主體應該是個人而不是民族或國家。不 過，根據Kok-Chor Tan的分析，此一爭論的更深層的原因是：羅爾 斯想追求一種獨立於整全式學說的政治正義觀，而Tan認為這不可能 成功。Tan認為唯有訴諸於整全式自由主義的個人自主性觀念，自由 主義才不會自我挫敗。本文作者認為Tan的批評是基於他對羅爾斯的 建構論方法的誤解。為了澄清羅爾斯的政治建構論，本文詳細地闡釋 羅爾斯的合理性的概念、迴避的方法、以及證立觀。透過此一分析， 本文試圖展現羅爾斯進路的內在一致性，由此襯托出何以訴諸整全式 的自由主義是不可行的，並透過這一方式間接地為羅爾斯的「以民族 為中心」的進路辯護。

Most cosmopolitan liberals are discontented with John Rawls’s theory of global justice. They believe that the basic unit of moral concern should be individuals not peoples, and Rawls’s “people-centric” approach is accountable for the flaws of The Law of Peoples. According to Kok-Chor Tan’s analysis, however, this debate has a deeper root. He argues that the flaws of Rawls’s The Law of Peoples are an accentuation of a problem inherent in political liberalism itself, i.e., Rawls’s aspiration for a conception of justice independent of comprehensive doctrines, which Tan contends impossible. Tan believes that only by appealing to comprehensive liberalism’s idea of individual autonomy can liberalism avoid being self-defeating. In this article I argue that Tan’s contention is based on misunderstandings of Rawls’s method of constructivism. In order to clarify the nature of Rawls’s political constructivism, I explain in details Rawls’s ideas of the reasonable, method of avoidance, and justification. Through this explication of Rawls’s ideas, I attempt to reveal the internal integrity of Rawls’s constructivist approach, which by contrast also helps to explain why appealing to comprehensive liberalism is implausible. By refuting Tan’s criticism of Rawls, I also mean to offer indirectly a defense of Rawls’s “people-centric” approach.