As lawyers know, the legal systems of countries around the world generally fall into one of two main categories: common law systems and civil law systems. There are about 150 countries that can be described primarily as civil law systems, while there are about 80 common law countries. Constitutions are very different. Some address serious internal ethnic, linguistic, and religious differences, while others are written for a homogeneous population. Some are largely confined to a set of justified legal norms, while others contain manifest proclamations. Some do not appear in any text, notably in Andorra, Israel, New Zealand and the United Kingdom. The American legal system and other legal systems based on British rule are a common law system.44 Originally, the common law meant law made by judges that filled gaps where there was no written law. The judges looked at previous decisions to determine unwritten judicial law and apply it to new cases. Today, however, almost all laws are written and enacted by a legislator as laws. Many statutes codify, amend or abolish the established common law, depending on the purpose of the statute.
There are cases where an unwritten common law is still applied, but these are rare. The main difference between the two systems is that, in common law countries, case law — in the form of published legal opinions — is paramount, whereas in civil law systems, codified statutes predominate. But these divisions are not as clear as they seem. In fact, many countries use a mixture of features of general and civil law systems. To understand the differences between these systems, we must first understand their historical foundations. In these systems, judges are heavily involved in investigations and facts, and the adversarial litigation system and precedents – two important elements of other legal systems – are of limited importance. Summary of the differences between civil and common law legal systems As a general rule, there are few generalizations that can be made between different constitutions. First, constitutions seek to regulate the division of powers, functions and duties among various agencies and government officials, and to define the relationship between them and the public. Second, no constitution, no matter how good, can protect a political system from effective usurpation. Third, those in power in many countries are more or less completely ignorant of the constitution. Fourth, even when constitutions do, none is complete: each operates within a matrix of compromises, customary laws or jurisprudence. Fifth, most begin by identifying (at least on paper) the constituent authority (as “the people”) and often invoke the deity (i.e., Canada, Germany, Greece, Ireland, Pakistan, Switzerland).
Sixth, as a rule, they separate the legislative, executive and judicial organs of the State. Seventh, they usually contain or incorporate a bill of rights. Eighth, they often provide a method of repealing laws and other unconstitutional instruments, including the Bill of Rights. Ninth, they approach the international scene only in general terms and in practice confer extensive powers on the (federal) executive. Finally, they deal with the status of international law, either by giving it direct internal effect or by denying it. Whatever their origin, most legal systems agree on certain fundamental premises. First, no one can be guilty of a crime if the offence has not been previously defined as such and if the sentence has not been pronounced through a legal procedure. This implies the need to clarify criminal law, prohibit its retroactive effect and certain notions of “fair trial” and the availability of a lawyer. Second, no one can be prosecuted twice for the same thing. Third, it is a crime to attempt a crime or conspire with others to commit one. Fourth, an alleged criminal must have a certain mindset to be convicted of the crime. Civil law countries include all of South America (except Guyana), almost all of Europe (including Germany, France and Spain), China and Japan.
A common method is to require a special majority in the legislature – two-thirds in Germany, three-fifths in France, with similar systems in India and other Commonwealth countries (and this was the case in the Soviet bloc). Another parliamentary alternative is to ask for a second vote (Italy, Denmark, Finland). Finally, some systems divide the power of amendment between legislators and citizens by requiring a referendum either for certain types or methods of change (Denmark, France, Ireland) or for each (Japan). In both civil and common law countries, lawyers and judges play an important role. Here is a discussion of civil law systems versus common law systems: Lawyers still represent the interests of their clients in civil proceedings, but have a less central role.