Law is a social system that regulates human behavior, provides protection for individuals and property, and promotes fairness and equity. The law encompasses a broad range of subjects, such as contracts; the carriage of goods; air, water, and maritime law; intellectual property rights; and criminal law. Its scope and influence vary from country to country. The law’s most basic functions are establishing standards, maintaining order, resolving disputes, and protecting liberties and rights. It is the underlying structure that distinguishes nation-states (as countries are called in international law). The law is the product of political action; therefore, it differs greatly from one polity to another. The political landscape also shapes the law; it is not uncommon for revolutions to occur against existing regimes in order to alter the political-legal environment and to bring about a different set of laws.
The notion of the rule of law is central to legal philosophy and jurisprudence. The idea was first developed by Aristotle and later elaborated upon by Montesquieu, who distinguished between the rule of law and other forms of government such as absolutism, tyranny, or totalitarianism. The notion of the rule of law is designed to ensure that both the government and private actors are held accountable under the law. This entails that laws are open, clear, publicized, stable, and applied evenly. It also ensures that citizens are equal before the law and are not subject to arbitrary power by any entity at the top of the government hierarchy.
This concept is a crucial element of Western liberal thought and has profoundly shaped the modern world. However, critics of the idea argue that excessive attention to the law and legal procedures can generate significant vices of its own in the form of exaggerated legalism and neglect of the political or real-world dimensions of legal conflicts. Some of these vices can even undermine the very integrity of the legal system by obscuring the societal benefits and costs of specific policy proposals or giving legitimacy to actions that most people would not want.
The law in each polity is defined by a combination of many factors, including its history and culture. It is important to understand these differences in order to appreciate the role that law can play in a given society. For example, in civil law societies that are former colonies of continental European nations, the laws may have been influenced by the Roman-Dutch legal tradition or by Islamic law. However, in mixed jurisdictions (such as those found in the Americas, Africa, or Asia), the laws have been a mix of common law and civil law traditions or other legal systems. See individual articles on these topics for further discussion of the law in each region. For articles that delineate the relationship of law to governmental structures, see constitution; ideology; political party; and political system. For articles that discuss the impact of the law on social justice issues, see human rights; land reform; and social service.