I wanted to show that there is a strong empirical evidence that obedience to the law is based rather on procedural justice than on substantive justice, because the assessment of substantive justice of the law requires a very sophisticated normative reasoning. Procedural justice is comprehensible by a common sense based on practical experience of citizens who deal with the law executing institutions such as the police and the courts. The intermediary variable is the legitimacy of the law executing institutions such as the police and the courts. Due to a low level of trust and approval of the law-making institutions such as parliaments and governments their legitimacy is questionable, and thus the law makers cannot foster the moral duty to obey the law among subjects to the law.