Judiciary

The judiciary is a complex system of courts.

Its primary role is to adjudicate legal disputes. This means the judiciary settles disagreements between people or groups. It also interprets, defends, and applies the law in legal cases. Under the doctrine of the separation of powers, the judiciary is distinct from other branches. The legislature is responsible for making statutory law. The executive branch is responsible for enforcing the law. The judiciary focuses on applying the law to specific facts.

In some countries, the judiciary can change laws through judicial review. This allows courts to annul laws that conflict with a higher norm, such as a constitution.

The history of the judiciary traces back to ancient Rome. During the Archaic period, between 650 and 264 BC, Romans used Ius Civile, or civil law. This included Mos Maiorum, which were social norms from ancestors. In 451–449 BC, these rules were written in the Twelve Tables. The legal process had two distinct phases. First, the In Iure phase involved a judicial process led by priests. Then, the Apud Iudicem phase brought the case before citizen judges. These judges were orators rather than legal experts. In the pre-classical period, the head of the system shifted from priests to praetors. These leaders issued edicts that created praetorian law.

The Roman Empire brought further changes to legal mechanisms. During the Principate, a new process called cognitio extraordinaria emerged. This was a single-phase process used because of the empire's vast size. A professional judge, representing the emperor, handled the case. Appeals were possible to an immediate superior. Legal experts also began to emerge during this era. They studied the law and acted as advisors to the emperor. Later, during the Dominate era, the leader Justinian oversaw a major event. He ordered the codification of Roman law into the Corpus Iuris Civilis.

This collection had four parts: the Institutiones, the Digesta, the Codex, and the Novellae.

In the Middle Ages, legal education expanded through new universities. These institutions had five faculties, including canon law and Ius Civile. Canon law, or ecclesiastical law, was created by the Pope. Secular law was mainly based on the rediscovered Corpus Iuris Civilis. The period of the Scholastics saw a renewed interest in these old texts. Early scholastics, such as the Glossators, worked to translate and recreate Roman law. They created Glossae, which were translations, and Summae, which were summaries. They also used Brocardica, or short mnemonic sentences, to help memory. Later, the Post-Glossators or Commentators analyzed law more systematically.

Church law also underwent significant organization during this time. A monk named Gratian was a well-known figure in this field. He organized church laws into a collection called the Decretum. This formed part of the Corpus Juris Canonici. This system was used by the Roman Catholic Church for centuries. By the 15th century, Roman law and canon law began to merge. This combined system was known as Ius Commune. It created a more systematic way to manage legal processes. This new process allowed for appeals and used different investigative methods. It was partially inquisitorial, where judges investigated evidence, and partially adversarial.

Modern legal systems use different methods to reach decisions. Common law jurisdictions rely heavily on precedent. This is known as stare decisis, or following previous court decisions. In these systems, courts can make law in limited areas, such as torts. For example, the tort of negligence often comes from case law rather than statutes. In contrast, other systems may be more inquisitorial. In the United States, the court system has a specific hierarchy. Cases begin in trial courts, such as US district courts. They can then move to appellate courts. The Supreme Court serves as the final authority on the federal Constitution.

Different countries maintain different structures for their highest authorities. In France, the Council of State handles administrative cases. The Court of Cassation handles civil and criminal cases. In the People's Republic of China, the National People's Congress is the final authority. Argentina uses a mixed system with various court levels. In the Argentine system, criminal cases involve four stages of litigation. This is one more stage than is required for civil law cases. Regardless of the specific structure, the judiciary remains a core pillar of organized society.