Pluralism is one of the key challenges of constitutional law in the 21st century. It has been developed away from the reality of constitutional law. Modern constitutional law is historically linked to the concept of the nation-state, a political community formed by a homogenous society in which citizens share the same history, glory, hero and language, and feel a strong mutual sense of belonging. The 21st century societies are different from this model because they are made up of a heterogeneous population that often does not share a common history, nor have the same heroes and language. These are societies in which opinions differ on fundamental issues of social organization and citizens have different worldviews and lifestyles. Although Eugen Ehrlich lived in the late 19th century and early 20th century, he worked in a region, Bukovina, which was a symbol of diversity. Thus, Ehrlich had the opportunity to consider the law in a different way than was possible in the great centers of European legal culture. His observations of the living law of the various communities that had formed in Bukovina enabled Ehrlich to develop a very particular theory of law with different categories. The work of Ehrlich offers the opportunity to harmonize legal pluralism with constitutional law. Living law and association are two central concepts in this process, but just as valuable is the distinction between legal norm and legal precept, because legal validity makes a major difference in this double dimension of law. The legal form fundamentally influences empirical law, especially in cases of conflict. However, law as an order of ordinary behavior also has validity through its effect.