Legal doctrine refers to the established principles and rules that guide the interpretation and application of laws within a legal system. It encompasses the theories and philosophies that underpin legal reasoning, helping judges and lawyers understand how to apply laws to specific cases. Legal doctrines can evolve over time through court decisions and legislative changes. In many jurisdictions, legal doctrine is influenced by case law, which consists of past judicial decisions that set precedents for future cases. Additionally, legal doctrines can be shaped by statutory law, which is created by legislatures, and by constitutional law, which outlines the fundamental principles of a legal system.