Are Civil Law and Common Law Families Converging?

Last week, I discussed whether all legal systems are mixed. Today, I am taking this thought a little bit further by examining whether there is a de facto convergence of civil law and common law families. In a world where people are coming together through travel, trade and internet, would it not be normal for legal systems to merge as well? Is not the consequence of international relations and treaties, that laws assimilate? Is the classical divide between civil law and common law becoming less and less pronounced? In order to be able to answer these questions, let us first look at the basic characteristics of common and civil law and then examine how they have changed in recent years and whether these changes suggest a convergence.

What Characterizes Civil Law and Common Law?

The civil law tradition goes back to the Corpus Iuris Civilis, a codification of Roman law. Civil law is mainly based on codes that are then interpreted by courts in individual cases. A main characteristic of these codes is that the rules are formulated in a very broad, general way and need to be applied in a strict, logical way.

Common law evolved in England from the 11th century onward. Its basis are court decisions of individual cases from which more general rules are drawn. These rules are usually much more specific and fact-driven than the ones in civil codes.

So Is There a Convergence?

Proponents of a merger of civil and common law point towards international legal communities and suggest that both legal systems have to come together in order for such meta-systems to work. The European Union (EU) might serve to illustrate this point. Thus, one could say that the EU issues written laws and has courts that make binding decisions. Yet, the EU statutes do not share the typical attributes of civil codes. And the way binding EU court decisions are handled by civil law courts falls short of the usual handling of precedents by common law courts. So while common law lawyers may increasingly have to deal with civil law issues and vice versa, the two systems are too fundamentally different in order to completely merge.


William Tetley, Mixed Jurisdictions: Common Law vs. Civil Law (Codified and Uncodified), 60 LOUISIANA L. REV. 618-738 (2000).

Clustering Legal Systems

In comparative law, there seems to be a general consensus that clustering legal systems is more practical – especially for macro-level comparisons. The prevalent method is to group legal systems into legal families. The notion of family has the advantage that the metaphor is expandable, i.e. parent-, sibling-, or cousin-laws. 

How are Legal Families Defined?

Different approaches, however, exist as to how a group of legal systems shall be defined. The challenge is to develop a classification method that merges similar legal systems in a most comprehensive way without being random or fragmented. This post will present five common criteria for grouping the legal systems of the world: (1) sources of law, (2) ideology and legal technique, (3) substance of the legal system, (4) legal style, and (5) tradition.

(1) Sources of Law

A straightforward way of classification is to divide the legal systems into groups that differ in terms of  sources of law. Usually, this method leads to the distinction of two groups:

  • common law countries and
  • civil law countries.

Common law countries base their legal systems on the English common law tradition, whereas civil law countries have codified law. Such a distinction is, of course, easy to do and avoids too much fragmentation. It is, however, very coarse and does acknowledge neither indigenous law nor the large diversity among the individual common and civil law systems.

(2) Ideology and Legal Technique

Another classification method looks primarily at a country’s ideology and, complementarily, at its prevailing legal technique. The ideology of a country is derived from looking at religion, philosophy, and political/economic/social structure. Originally, this methodology led to five legal families

  • Western systems,
  • Socialist systems,
  • Islamic law,
  • Hindu law,
  • Chinese law.

It was subsequently modified to include only three legal families:

  • Romanistic-German family,
  • Common law family, and
  • Socialist family

… plus a miscellaneous group of other systems that did not fit into these three groups.

This method is very comprehensive and considerably facilitates the comparative task. It does, however, not sufficiently recognize indigenous legal systems. In addition, it requires sometimes detailed knowledge of the law in order to know into which family a certain legal system fits.

(3) Substance of the Legal System

A different way of grouping legal systems is to focus on their substance, in particular their originality, derivation, and common elements. This classification method arrives at seven legal families:

  • French family,
  • German family,
  • Scandinavian family,
  • English family,
  • Russian family,
  • Islamic family,
  • Hindu family.

Again, grouping legal systems according to their substance avoids fragmentation and therefore facilitates the comparative task. It represents, however, a very subtle classification and leaves out certain (indigenous) systems.

(4) Legal Style

The idea of style is derived from the arts. In law, style is characterized by historical background and development, mode of legal thought, distinctive institutions, recognized legal sources, and ideology. From this follows a division into eight legal families:

  • Romanistic family,
  • Germanic family,
  • Nordic family,
  • Common law family,
  • Law of the PeoplesRepublic of China,
  • Japanese law,
  • Islamic law, and
  • Hindu law.

Using style for the classification of legal systems brings similar benefits and challenges as the use of substance as a tool: it facilitates the comparative task by grouping legal systems into few families, yet classification can be very subtle and some (indigenous) laws is not given sufficient credit.

(5) Tradition

A rather new way of grouping legal systems is to look at how they transmit information from the past to the present. From this follows the distinction of seven legal traditions:

  • Chthonic legal tradition,
  • Talmudic legal tradition,
  • Civil law tradition,
  • Islamic law tradition,
  • Common law tradition,
  • Hindu legal tradition, and
  • Asian legal tradition

This grouping method still avoids fragmentation, while at the same time being very comprehensive and including indigenous systems. Its classification criteria are, however, very subtle and therefore this method requires excellent knowledge of the legal systems and their cultures and traditions.

Assessment of the Different Methods

The preceding presentation shows that neither of the described methods is perfect in an absolute sense. Rather, it depends on the context which of the above-explained methods – if any – should apply. For a comprehensive, but general comparison of laws, the traditions approach (5) seems appropriate. For a coarse confrontation of basic principles of private law in Europe and the United States, the simple distinction between common law and civil law may suffice. For a global functional analysis of a specific aspect or area of law, some variation of approaches (2) – (4) could be workable. If you are only interested in how an issue is addressed in a handful of countries, you do not really need to resort to clustering at all. Although a basic understanding of how legal systems relate to each other is always helpful. Finally, some areas of law need other differentiating factors. (E.g. in constitutional law, there are quite different interrelationships of legal systems). In sum, the above-described approaches provide a useful working basis for everyone who is interested in comparative law, though they may need to be adapted for each individual case.


  • Jaakko Husa, Legal Families, in ELGAR ENCYCLOPEDIA OF COMPARATIVE LAW 382-393 (Jan Smiths ed., 2006).