Judicial review is a principle of democratic political theory concerning the authority of courts over non-judicial branches of government. Specifically, judicial review is the examination of the actions of the executive, legislative and administrative branches of government by a country’s court system to determine whether those actions conform to the dictates of some previously established higher authority. In the case of a democracy, the higher authority most likely would be a written constitution, but in a theocracy, that authority would reside in a religion. If the laws or actions are found incompatible, then they might be subject to invalidation by the court system.
The origin of the doctrine lies in the philosophy behind the separation of powers seen in modern structures of government where the courts are enumerated as one of the branches of governance. Differing national political histories have caused divergent views to evolve concerning what the hierarchy among government branches should be. Consequently, the scope and procedures of judicial review law vary from country to country.
Civil law and common law are two connected but different legal systems that provide the basis for the diverging views of judicial review. The evolution of civil law was affected by the French Revolution in the 18th century and the eventual codification of law into the 1804 Napoleonic Code with its emphasis on the supremacy of the legislative body elected by the people. In legal systems that developed from civil law, the court system usually is specifically prohibited from making law as well as from challenging laws made by the legislative branch. The legal systems in Switzerland and the Netherlands are examples of this system.
Legal systems in countries that evolved from common law have a different view. In those systems, judicial review is considered to be a necessary check on legislative power and the determining of law by courts is commonly accepted. Countries that are based on common law and emphasize the separation of powers are the most likely to permit judicial review. The legal system in United States is an example of this type of system.
A hybrid view of judicial review also exists. Although its legal system is based on common law, in the United Kingdom, some types of laws can be reviewed by the courts, but primary legislation passed by Parliament cannot be reviewed. Interestingly, this seemingly dry subject is a flash-point of international tension in the European Union. Within the Union, judicial review powers reside in its Court of Justice, but many member states remain adamantly opposed to it as a legal doctrine.