正義感的優先性問題，關注的是理性個體為何及如何有足夠的動機去服從正義的要求。本文將指出，羅爾斯採納了正當與「好」彼此契合的論證回答此問題。契合論之所以必要，是因為羅爾斯對義務論的說明，以及正當優先於「好」的解釋，均沒有正式處理道德動機的優先性問題。要證成這種優先性，我們必須提出充足的理由，彰顯正義感乃我們人生計畫中最重要的「好」。羅爾斯的做法，是訴諸一個康德式的對公平式正義的詮釋。我將指出，契合論的最大問題，是在現代多元社會，人們各有不同的終極人生目標，羅爾斯的慎思理性觀無法保證所有理性者都接受康德式的對人性的詮釋。正是這個內部論證的不一致，迫使羅爾斯後期作出政治自由主義的轉向。

The question of the priority of the sense of justice is concerned with why and how rational individuals can have sufficient and effective motivation to comply with the demand of justice. This essay argues that John Rawls has adopted a theory of congruence of the right and the good to answer the question. This theory is necessary because Rawls's account of deontology and the notion of priority of the right over the good do not really deal with the problem of motivational priority. To justify this kind of priority, we must provide sufficient reasons to show that the sense of justice is the most important good in one's rational plan of life. Rawls's solution is to appeal to a Kantian interpretation of justice as fairness. I point out that the biggest problem of congruence is that in a modern pluralistic society, Rawls’s account of deliberative rationality cannot assure that all rational individuals would accept this Kantian interpretation of human nature given the diversity of ultimate ends. It is this internal inconsistency that forces later Rawls to make a turn to political liberalism.