When justifying the rule of morals, the advocates usually appeal to the vital functions of morality which are derived from the various comparisons between law and moralityBut this line of thought oversimplifies the complicated problems involved, and does not fully realize the huge gap between the premise and the desired conclusionGenerally speaking, this line of thought faces some important challenges, for example, how to derive value judgments from fact judgments, how to interpret the importance of moral construction, how to justify the necessity of states involvement into moral construction, and how to delineate the boundary of states powerFurthermore, when we try to examine the specific relationships between law and morality which are used by the advocates to justify the rule of morals, it shows that these relationships are either not relevant to the justification at all, or are still far away from the conclusionSome relationships even illustrate the importance of the rule of lawThis means that the advocates of the rule of morals either abandon this line of thought completely or can respond to the various problems appropriately