Law is the set of rules that governs a community and is enforced by a controlling authority through penalties. In most countries, laws are the product of a combination of legislative statutes and judicial decisions. Legislative statutes are created by legislatures, while judicial decisions are made by judges in courts. There are two main systems of law, common and civil, with each originating from different historical influences. Most nations today follow a legal system based on either of these, but some also have laws based on religion.
The concept of Law has been debated since antiquity, with a variety of approaches to understanding it. Some scholars have focused on the formal definition of Law, such as jurisprudence or legal theory, while others have explored its moral dimensions. The latter approach draws on ideas from philosophy, ethics and religion to develop a normative theory of Law that can guide the development of laws and the application of them in practice.
Most of the laws of today are based on an understanding of natural phenomena, such as the laws of gravity or Mendelian inheritance. These laws are based on empirical evidence, and they help to unify and explain a wide range of observations. Other laws, such as those governing human behavior, are based on theories that describe why and how they work, rather than what they are. Examples include the utilitarian approach of John Austin and the natural law theory of Jean-Jacques Rousseau, which posits that law reflects innate principles of morality.