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Foreign, Comparative, and International Law: Definitions

What's the Difference?

The first step to FCIL research is figuring out which body of law or area of scholarship is relevant. Many of these terms sound very similar, but subtle differences in meaning make a world of difference in application.

Foreign vs. Comparative vs. International

Foreign Law: The law of another country. 

  • One nation's domestic law is another nation's foreign law. Speaking from the point of view of the United States, the laws of China, France, and Nigeria are all "foreign law."
  • Since this guide is for students in the U.S., "foreign law" will be used to refer to the laws of countries and states outside the U.S.

Comparative Law: The scholarly study of the similarities and differences between the legal systems of different jurisdictions.

  • A comparison between the civil law system of Quebec and the common law system of Ontario would be in the realm of comparative law.
  • Paradoxically, "comparative law" might be a deep dive into a single body of law. If it is a scholarly study of a legal system, it is considered comparative law.
  • Comparative law by necessity starts with foreign law (or U.S. law), in that it is the actual laws of jurisdictions being compared.
  • Note that Comparative Law differs from Conflict of Laws, which in the FCIL context is known as Private International Law.

International Law: General term that usually refers to Public International Law (which differs significantly from Private International Law).

  • Public International Law: The legal system governing the relationships between countries and other participants in international relations, including international organizations and individuals. Also known as "the law of nations."
    • Treaties, international agreements, and intergovernmental organizations like the United Nations, are all examples of public international law.
    • Involves laws outside the creation of a single jurisdiction.
  • Private International Law: Conflict of laws, as applied to jurisdictions across national borders.
    • Involves the laws of multiple particular jurisdictions, e.g., Chinese contract law and Turkish contract law, or Panamanian intestacy law and Indian intestacy law, and how those laws interact with each other.
    • Frequently applied in commercial and business legal practice.

Other Important Terms

Civil Law: Major legal system that gives precedence to a systematic, written codification of general law.

  • Civil law is the most widespread legal system in the world and is the primary legal system of countries such as France, Germany, Mexico, and Turkey. 
  • Historically, Civil Law in the Western world descended from Roman law and includes the Napoleonic Code.
  • Note that while the United States maintains a codification of statutory laws, it is a Common Law nation. Interestingly, Louisiana is the only U.S. state with a mixed system, combining common law with its Civil, Napoleonic Code tradition.
  • "Civil Law" in this sense encompasses both criminal law and "civil law" as the term is used in the U.S. (like torts and contracts).

Common Law: Major legal system that gives precedence to case law over legislation.

  • The United States is a Common Law jurisdiction, which can be understood if you consider the priority given to the Federal courts' interpretation of Congressional legislation.
  • Historically, Common Law is based on the English Common Law tradition. As a result, nations with Common Law systems are generally current or former British territories, including Canada (minus Quebec), Australia, Jamaica, and the United States (minus Louisiana).
  • "Common Law" in this sense differs from the "common law" which refers to the body of law derived from judicial decisions, rather than statutes or constitutions.

See more on Civil Law, Common Law, and other legal systems on the Legal Systems page of this guide.

Intergovernmental Organizations: Organization composed primarily of sovereign states, or of other intergovernmental organizations, established by treaty or other agreement that acts as a charter creating the group.

  • Also known as International Governmental Organizations or IGOs, examples include the United Nations, the European Union, OPEC, NATO, and World Bank.
  • While the treaties and agreements that create IGOs are based on principles of public international law, some IGOs are rooted in supranational law, including the governing tribunals of the EU and the UN.

Supranational Law: Form of international law wherein sovereign nations submit to the judicial decisions of a common tribunal.

  • In public international law sovereign states negotiate with each other, while supranational law involves a tribunal outside of and above the authority of any state.
  • The major supranational tribunals are the European Union's European Court of Justice, the United Nations Security Council, and other U.N. organizations like the International Court of Justice.
  • The European Union itself is considered a supranational political entity. America's pre-Constitution Articles of Confederation was a supranational agreement among thirteen independent states who submitted (theoretically) to the authority of a common governing body.

Transnational Law: Umbrella term for all law which regulates actions or events that transcend national frontiers, including but not limited to public and private international law.

  • This term was coined by Professor Philip Jessup to counter the inadequacy of the term "international law," which is tied to public international law, wherein nations/states interact with other nations/states. (See Philip Jessup, Transnational Law, p. 2).
  • Transnational Law is not an actual body of law, but a legal concept (like Comparative Law). 
  • A similar term is FCIL, or "Foreign, Comparative, and International Law," which describes the general area of legal concepts beyond domestic legal doctrines.

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