  The notion of justification is very different on this view.  Moral facts fix the relevance of other factors. The moral principles that reflect those facts do not add content to the law, which needs to be combined with  content otherwise contributed by institutions. They determine which precise aspect of institutional practice is relevant to the practice’s contribution to the law. The moral facts are therefore fundamental to the constitutive explanation of law, but do not directly determine its content. They determine how institutional practice determines the law.