Law is a system of rules that governs social, economic and political activity. It imposes obligations and rights on people, defines property ownership, guarantees freedom of speech, prohibits certain types of discrimination, regulates commerce, establishes war-time restrictions, punishes crimes, and governs the activities of government. In addition, it reflects the customs and practices of societies and the responsibilities of the legal profession. Max Weber reshaped thinking on the extension of state power and its accountability, whilst the contemporary military, police and bureaucracy pose special problems that are not fully addressed by earlier writers such as Locke or Montesquieu. Law is a complex subject. For articles that explore particular branches of law see contract law; criminal law; family law; property law; tort law; and the legal profession.
Legal concepts include jurisprudence, legal theory, and methodology. Jurisprudence is the study of how courts decide cases, whereas legal theory is an academic discipline that seeks to understand why judges make the decisions that they do. Methodology is the process by which a judge or other person determines what the law means. This includes the principles of caselaw and precedent, a principle that states that when a court makes a decision in one case, it should be followed by future courts in similar cases.
In common law legal systems, the decisions of higher courts (e.g. the supreme court of a jurisdiction) are binding on lower courts in that same jurisdiction, and form what is known as the doctrine of stare decisis. In contrast, in civil law legal systems, the statutes that are passed through the legislative process and the regulations issued by the executive branch have greater priority than court decisions.
The scope of the law is vast and encompasses many areas of human life. For example, tort laws deal with the obligation to compensate others when they suffer harm, ranging from damage to cars and houses in an automobile accident to defamation of character. Other areas include immigration and nationality law, which concerns the right to live and work in a country other than one’s own; employment law; and family law, which covers divorce proceedings and rights to children and property after a separation. Commercial law covers the legal basis of business transactions, including agency, insurance, bills of exchange and insolvency and bankruptcy laws. The law of companies stems from the medieval Lex Mercatoria, which established the idea that a business could be considered a separate legal entity. In addition, there is a body of international law that is binding on all nations.