The unification and harmonisation of laws are similar in the sense that both involve approximating several legal systems and both are also oriented towards establishing some level of integration from a previous situation characterized by diversity. On the other hand, unification and harmonisation have different fundamental aims. The former works towards complete unity in substance and detail whereas the latter avoids complete uniformity, and is primarily concerned with approximating the fundamental principles of national laws. In unification, for example, a new law completely replaces the national laws that have existed before. A harmonisation law on the European level does not exceed mere approximation and leaves the national differences in place as long as they are not expressly regulated by the harmonising law. Here, national laws merely become closer but not identical.