The common law and civil law systems are the products of two fundamentally different approaches to the legal process. In civil law, the main principles and rules are contained in codes and statutes, which are applied by the courts codes. Hence, codes and statutes prevail, while case law constitutes only a secondary source of law. On the other hand, in the common law system, the law has been dominantly created by judicial decisions, while a conceptual structure is often lacking. This difference is the result of different role of legislator in civil law and common law. The civil law is based on the theory of separation of powers, whereby the role of legislator is to legislate, while the courts should apply the law. On the other hand, in common law the courts are given the main task in creating the law.
The civil law is based on codes which contain logically connected concepts and rules, starting with general principles and moving on to specific rules. A civil lawyer usually starts from a legal norm contained in a legislation, and by means of deduction makes conclusions regarding the actual case. On the other hand, a lawyer in common law starts with the actual case and compares it with the same or similar legal issues that have been dealt with by courts in previously decided cases, and from these relevant precedents the binding legal rule is determined by means of induction. A consequence of this fundamental difference between the two systems is that lawyers from the civil law countries tend to be more conceptual, while lawyers from the common law countries are considered to be more pragmatic.
One of the main differences between the civil law and common law systems is the binding force of precedents. While the courts in the civil law system have as their main task deciding particular cases by applying and interpreting legal norms, in the common law the courts are supposed not only to decide disputes between particular parties but also to provide guidance as to how similar disputes should be settled in the future. The interpretation of a legislation given by a court in specific case is binding on lower courts, so that under common law the court decisions still make the basis for interpretation of legislation.
On the other hand, in contrast to common law, the case law in civil law systems does not have binding force. The doctrine of stare decisis does not apply to civil law courts, so that court decisions are not binding on lower courts in subsequent cases, nor are they binding on the same courts, and it is not uncommon for courts to reach opposite conclusions in similar cases. In civil law the courts have the task to interpret the law as contained in a legislation, without being bound by the interpretation of the same legislation given by higher courts; this means that under civil law, the courts do not create the law, but only apply and interpret it. In practice, however, the higher court decisions certainly have a certain influence on lower courts, since judges of lower courts will usually take into account the risk that their decisions would probably be reversed by the higher court if they contradict the higher court decisions. Judges normally try to avoid the reversal of their decisions by higher courts as if too many of their decisions are reversed their promotion may be adversely affected. Hence, even though in civil law systems the case law formally has no binding force, it is generally recognized that courts should take into account prior decisions, especially when the settled case law shows that a line of cases has developed.