Understanding comparative constitutional law can be challenging for researchers only familiar with American domestic law or common law systems. This page covers basic knowledge that is helpful for beginning your research in comparative constitutional law, including basic definitions, how to distinguish foreign and international law, information on citations from foreign jurisdictions, and some unique challenges for researching in this area.
For legal researchers based in the United States of America, foreign law refers to the domestic law of other nations. Comparative law is the study of the differences between the laws of two or more countries, or between two or more legal systems.
The legal systems of most countries fit into the following categories of legal traditions, with many nations combining elements from multiple traditions to form their own unique systems:
| Legal System | Brief Description & Country Examples |
| Civil Law |
Based on Roman law, the civil law system is comprised of comprehensive codes governing specific areas of law (criminal, civil, commercial, civil procedure, criminal procedure, etc.). Commentaries written by legal scholars interpret, criticize, and develop the law, and these commentaries carry great influence as compared to the lesser weight given to judicial opinions. The civil law system is perhaps the largest legal tradition and characterizes the systems of most of the countries in continental Europe, Latin America, and parts of Asia and Africa. |
| Common Law |
Legal doctrine in the common law system is developed over time through judicial opinions, rather than from broad comprehensive codes. Judicial decisions are traditionally the most important source of new legal rules in the common law system. The common law system originated in England, and it can be found today in other nations with a connection to the British Commonwealth. These nations include the USA, Canada, Australia, New Zealand, and India. |
| Customary Law |
Customary law is rarely a standalone legal system and is instead typically melded together with elements from other legal traditions. Custom is often rooted in a nation's daily experiences and spiritual/philosophical traditions. Andorra and the Channel islands of Guernsey (UK) and Jersey (UK) are the only three areas that have what legal scholars today would consider "customary law monosystems," meaning legal systems that are truly derived from customary law and not mixed with other legal traditions. |
| Religious Law |
Religious legal systems are based largely on traditional religious texts. Similar to customary law systems, many nations today have mixed systems with elements of the religious legal system mixed with another legal system, typically civil law. The religious legal system is most frequently found in areas that practice Islamic or Talmudic law. An example of a religious law monosystem is Saudi Arabia. |
Note: Many modern jurisdictions have what are referred to as "mixed" legal systems. These legal systems combine elements from two or more legal systems to reflect the unique needs of that jurisdiction. For example, the Canadian province of Quebec has a mixed legal system that combines elements of both the common and civil law traditions. (For more information on Quebec's particular use of a mixed legal system, see this piece on the Canadian Department of Justice's website.)
If you are interested in learning more about the individual legal systems and the nations which practice those systems, the University of Ottawa's online database JuriGlobe: World Legal Systems is an excellent resource that provides maps, descriptions of the major systems, and lists of the countries practicing each legal system.
Before getting started with research in the area of foreign and comparative law, make sure that what you are seeking is not actually an international law topic.
Public international law can be generally defined as "the law of nations." It encapsulates a variety of different legal subjects, including diplomatic relations, treaties, international organizations, and customary international law. It largely governs and structures the interactions between nation states and international organizations.
The UNC Law Library has a separate research guide that explores public international law research. Please check out this guide for an overview of treaties research, international organizations, and international courts/tribunals.
Private international law describes the body of law which governs when there is a conflict between the citizens of different countries. While you will ultimately end your research process in the domestic law of a specific jurisdiction, you should begin by having a thorough understanding of the correct analysis to use.
The following research guides provide a basic overview of conducting legal research in the area of private international law:
The following are brief caveats for conducting legal research in a foreign nation. Keep these caveats in mind as you begin your research and recognize that foreign law research is different and oftentimes more complicated than researching in US law.
When in doubt, stop by the UNC Law Library Reference Desk! The librarians are happy to work with you in identifying and locating primary law materials for your jurisdiction of interest.
One of the biggest roadblocks in conducting foreign legal research is encountering materials in a language other than English. The following are some suggested machine language translation services that can be used to roughly translate legal materials. Be sure to approach machine translations of foreign legal materials with skepticism, as you have no way of assessing the accuracy or reliability of the translations.
If you encounter an unfamiliar or incomplete citation during your research process, there are several resources that you can use to identify the complete name of the resource.
