Law is a system of rules a society or government develops to deal with such things as crime, business agreements and social relationships. It is often defined in terms of its function as a means of social control and the satisfaction of social wants, against the background of cultural tradition, history and legal technique.
The nature and function of laws is debated by philosophers and political theorists. For example, utilitarian theories argue that law provides a mechanism to ensure social harmony and imposes an order on human actions. Others, such as natural lawyers, such as Jean-Jacques Rousseau, argue that laws are derived from an innate morality and unchanging principles of nature. The role of the state in making and enforcing laws is also debated. Max Weber reshaped thinking on the extension of state power that earlier thinkers such as John Locke and Montesquieu could not have envisaged.
Some countries use a common law system, which relies on decisions of judges and is not explicitly codified, while others, such as Japan, have civil law systems that are written out in statutes. Other areas of the law include:
Contract law governs agreements to exchange goods or services; tax law deals with paying taxes and other duties; family law deals with marriage, divorce and children; and constitutional law covers the basic tenets that underlie society. There is even a branch of law called biolaw, which looks at the intersection between law and the life sciences.