Civil law is primarily contrasted against common law, which is the legal system developed among Anglo-Saxon people, especially in England. The original difference is that, historically, common law was law developed by custom, beginning before there were any written laws and continuing to be applied by courts after there were written laws, too, whereas civil law developed out of the Roman law of Justinian’s Corpus Juris Civilis (Corpus Iuris Civilis). In later times, civil law became codified as droit coutumier or customary law that were local compilations of legal principles recognized as normative.
Sparked by the age of enlightenment, attempts to codify private law began during the second half of the 18th century (see civil code), but civil codes with a lasting influence were promulgated only after the French Revolution, in jurisdictions such as France (with its Napoleonic Code), Austria (see ABGB), Quebec (see Civil Code of Quebec), Spain (Codigo Civil), the Netherlands and Germany (see Burgerliches Gesetzbuch).
However, codification is by no means a defining characteristic of a civil law system, as e. g.the civil law systems of Scandinavian countries remain largely uncodified, whereas common law jurisdictions have frequently codified parts of their laws, e. g. in the U. S. Uniform Commercial Code. There are also mixed systems, such as the laws of Scotland, Louisiana, Quebec, Namibia and South Africa. Thus, the difference between civil law and common law lies less in the mere fact of codification, but in the methodological approach to codes and statutes. In civil law countries, legislation is seen as the primary source of law.
By default, courts thus base their judgments on the provisions of codes and statutes, from which solutions in particular cases are to be derived. Courts thus have to reason extensively on the basis of general rules and principles of the code, often drawing analogies from statutory provisions to fill lacunae and to achieve coherence. By contrast, in the common law system, cases are the primary source of law, while statutes are only seen as incursions into the common law and thus interpreted narrowly. The underlying principle of separation of powers is seen somewhat differently in civil law and common law countries.
In some common law countries, especially the United States, judges are seen as balancing the power of the other branches of government. By contrast, the original idea of separation of powers in France was to assign different roles to legislation and to judges, with the latter only applying the law (the judge as la bouche de la loi; ‘the mouth of the law’). This translates into the fact that many civil law jurisdictions reject the formalistic notion of binding precedent (although paying due consideration to settled case-law), and that certain civil law systems are based upon the inquisitorial system rather than the adversarial system.
There are other notable differences between the legal methodologies of various civil law countries. For example, it is often said that common law opinions are much longer and contain elaborate reasoning, whereas legal opinions in civil law countries are usually very short and formal in nature. This is in principle true in France, where judges cite only legislation, but not prior case law. (However, this does not mean that judges do not consider it when drafting opinions.)
By contrast, court opinions in German-speaking countries can be as long as English ones, and normally discuss prior cases and academic writing extensively. There are, however, certain sociological differences. Civil law judges are usually trained and promoted separately from advocates, whereas common law judges are usually selected from accomplished and reputable advocates. Also, the influence of articles by legal academics on case law tends to be much greater in civil law countries.