Stare decisis has been translated variously but it stands for the idea that the case at hand is to be decided according to the decisions of similar cases in the past. In other words, precedents shall rule the future. It's important because it gives stability, predictability, and integrity to the law. Indeed, it is one of the foundational principles for the very idea of the rule of law as opposed to the rule of man. The origins of stare decisis can be found in the idea of law itself but we find it especially in the English and American common law. The origins of the common law are rooted in the third quarter of the twelfth century under Henry II who established a series of circuit courts and one central appellate court. When you have a system like that, you have the appellate court sometimes adjudicating conflicts that occur in the lower courts and then establishing a precedent which enables stare decisis to take hold because subsequent cases will then be decided under that precedent. In the American legal system, stare decisis is of particular importance in the common law, which is usually enforced, for the most part, by state courts. This is especially important in the business world, the commercial world, because businesses need to know what the law is so that they can plan accordingly. Judges are bound by the precedents in their own circuit and they are often persuaded by precedents in other circuits that may be instructive for a case before the court that is one of first impression. And the judges, of course, are bound by the precedents that come from the court above them. And that is especially the case in our 50 states where you have a supreme court and lower courts and also at the federal level with the US Supreme Court, appellate courts, and then trial courts. Stare decisis plays a prominent role in constitutional law as well. It turns out that the Supreme Court overturns its precedents rather less than is commonly believed. Moreover, the concept of stare decisis is consistent with the Constitution's being the supreme law of the land. Once again, because the rule of law requires stare decisis. If a court was free to decide every case on its own merits, irrespective of similar cases having been decided a certain way in the past, then we'd never know, really, what the law was. Stare decisis is not an absolute principle. Stare decisis has enabled American law to be an example for the rest of the world about a system of law that can truly be called law because it enables us to know what behavior is or is not acceptable, to plan accordingly, and therefore to flourish both personally and economically.