Stare decisis is a Latin term used in common law to express the notion that prior court decisions must be recognized as precedents, according to case law. The term means: "let the decision stand". This doctrine is not held within most civil law jurisdictions as it is argued that this prinicple interferes with the right of judges to interpret law and the right of the legislature to make law. Most such systems, however, recognize the concept of jurisprudence constante, which argues that even though judges are independent, they should rule in a predictable and non-chaotic manner.
In general, a common law court system has trial courts, intermediate appellate courts and a supreme court. The lower courts administer most day-to-day justice. The lower courts are bound to follow precedents established by the appellate court for their region and the supreme court. Appellate courts are only bound to follow supreme court decisions. The application of the doctrine of stare decisis from a higher court to a lower court is sometimes called vertical stare decisis.
A supreme court is not bound by any lower precedent and, today in most jurisdictions, a court of last resort may overturn its own precedents if warranted; see the Practice Statement made by the House of Lords, a well known example of such principle in Commonwealth countries. Stare decisis nonetheless operates in a supreme court as a discretionary principle by which the court will not overturn its own precedents in the absence of a strong reason to do so, in order to foster predictability of the law.
In the United States federal court system, the intermediate appellate courts are divided into "circuits". Each panel of judges on the court of appeals for a circuit is bound to follow the prior appellate decisions of the same circuit. Precedents of a United States court of appeals may be overruled only by the court en banc, that is, a session of all the active appellate judges of the circuit, or by the United States Supreme Court. When a court binds itself, this application of the doctrine of precedent is sometimes called horizontal stare decisis. The State of New York has a similar appellate structure as it is divided into four appellate departments supervised by the final New York State Court of Appeals. Decisions of one appellate department are not binding upon another, and in some cases the departments differ considerably on basic points of law.
And while lower courts are bound in theory by higher court precedent, in practice judges may sometimes attempt to evade precedents, by distinguishing them on spurious grounds. The appeal of a decision that does not follow precedent may also not occur as the expense of an appeal may prevent the losing party from doing so and thus the lower court decision may stand even though it does not follow the higher court decision as the only way a decision can enter the appeal process is by application of one of the parties bound by it.
Stare decisis also occasionally results in court decisions in which the judge explicitly states personal disagreement with the judgment he or she has rendered but that he or she is required to do so by binding precedent.
In the United States, stare decisis can interact in non-intuitive ways with the federal and state court systems. On an issue of federal law, a state court is not bound by an interpretation of federal law at the district or circuit level, but is bound by an interpretation by the United States Supreme Court. On an interpretation of state law, whether common law or statutory law, the federal courts are bound by the interpretation of a state court of last resort, and are normally required defer to the precedents of intermediate state courts as well.
Courts may choose to follow precedents of other jurisdictions, but this is not an application of the doctrine of stare decisis, because foreign decisions are not binding. Rather, a foreign decision that is followed on the basis of the soundness of its reasoning will be called persuasive authority--indicating that its effect is limited to the persuasiveness of the reasons it provides.
Stare decisis is not usually a doctrine used in civil law court system, because it violates the principle that only the legislature may make law. In theory therefore, lower courts are generally not bound to precedents established by higher courts. In practice, the need to have predictability means that lower courts generally defer to precedents by higher courts and in a sense, the highest courts in civil law jurisdictions, such as the Cour de cassation and the Conseil d'État in France are recognized as being bodies of a quasi-legislative nature.
The doctrine of stare decisis also influences how court decisions are structured. In general, court decisions in common law jurisdictions are extremely wordy and go into great detail as to the how the decision was reached. This occurs to justify a court decision on the basis of previous case law as well as to make it easier to use the decision as a precedent in future cases. By contrast, court decisions in civil law jurisdictions tend to be extremely brief, mentioning only the relevant legislation and not going into great detail about how a decision was reached. This is the result of the civil law view that the court is only interpreting the view of the legislature and that detailed exposition is unnecessary. Because of this, much more of the exposition of the law in civil law nations is done by academic jurists which provide the explanations that in common law nations would be provided by the judges themselves.
There is much discussion about the virtue and irrationality of using case law under such a system. Supporters of the system argue that it makes decisions predictable, that is, a business person can be assured of the same decision in the same sort of case. The argument most often used against the system is that it is undemocratic as it allows unelected judges to make law.
