Monopoly on violence
In most systems of law, certain organisations are authorised to use violence against people who violate the law, and to imprison
those people. These organisations have different names such as police, security guards, paramilitary forces and secret services.
This principle is not universal, however.
External references
Use of violence
The most common theoretical constraint on the use of violence by members of these organisations is that they are only allowed to use a minimum of violence for self-defence or to prevent a violent action necessarily going to occur, and should be carried out using a "proportionate" amount of force. See also use of force[?] deadly force
Use of imprisonment - habeas corpus
In theory, any imprisonment is usually only allowed to be temporary, while the legal process[?] starts happening for the allegations against the accused to be written down, analysed and judged according to the written down law of the nation-state.
Is violence necessary for a legal system?
Some people claim that a de facto legal system is possible without the use of violence - see anarchist law.