Chapter 1, in its subsection on objectivity qua invariance, has contended that we cannot correctly ascribe either unchangingness or ubiquity to the substance of law. As was remarked at the end of that subsection, however, the formal features of law are quite different from the substance. Certain formal features are present whenever and wherever law exists. No legal system can operate without those essential attributes, regardless of the time or the place.

Even in connection with the formal side of law, nevertheless, any ascription of unchangingness and ubiquity would be more misleading than illuminating. One of the salient themes of this chapter is that, although the fundamental characteristics of the rule of law are always present when a functional legal system exists, their substantive significance can vary considerably. On the one hand, those fundamental characteristics are content-independent in that they structure every legal regime regardless of the benignity or malignity of its norms. A legal system as a legal system partakes of those characteristics, whether the contents of its laws and the purposes pursued by its officials are commendable or deplorable. On the other hand, the substantive import of the essential properties of law is hugely affected by the substance of each legal system in which they are instantiated. Although those properties do not have any inherent moral bearings, they acquire moral bearings from the character of any regime in which they exist.