Law is the system of rules and principles that governs a society and its members, often enforced by a controlling authority through penalties. Laws are generally based on social conventions and customs, but can also be written or enacted by a government body.
The practice of law involves the use of legal documents to settle a dispute, prosecute criminals or civil lawsuits and defend clients in litigation. It also covers the rights and responsibilities of citizens in their daily lives. It encompasses a wide range of areas including immigration and nationality, family and property law. Business and transactional law, environmental and intellectual property are other areas of the practice of law.
In the United States, federal law is largely created by statutes, duly enacted laws passed by Congress and compiled into the United States Code. Statutes can be amended by subsequent laws, and some statutes empower executive branch agencies to create regulations that carry the force of law. Judicial interpretations of laws and regulations are binding under the principle of stare decisis.
There is a theory of law called legal positivism that holds that the law is a set of written rules that reflect the will of the sovereign. Critics of legal positivism argue that it fails to recognize the ways in which laws reflect moral considerations and are designed to prevent injustice. For example, the prohibition against insider trading is a matter of fairness, and due process is a moral position against cruelty.
The practice of law requires extensive knowledge and understanding of the legal system, its institutions and procedures. Most practicing lawyers achieve their distinct professional identity by meeting specific legal requirements, completing a legal education that earns them a Bachelor of Laws or a Bachelor of Civil Laws, passing a bar examination and being admitted to the practice of law.
Many legal fields are heavily regulated. For example, banking law regulates the amount of capital that banks must hold, and rules about best practices for investment. This is in part to protect consumers against financial crises, like the Wall Street Crash of 1929. Environmental law is another heavily regulated area that deals with issues such as pollution, toxic waste and endangered species.
Competition law is a growing field that seeks to control businesses that manipulate prices and reduce consumer choice. It draws on older laws like Roman decrees against price fixing and English restraint of trade law. Similarly, intellectual property law is an ever-evolving field that addresses new technologies such as biotechnology and the Internet. However, some critics argue that regulating these fields is harmful to the free flow of ideas and stifles innovation. A more recent development is the concept of cultural law, which seeks to protect the right of indigenous peoples to maintain their own cultures. This has been controversial, especially when the law is used to appropriate culture for commercial purposes.