Libertarian theories of law build upon classical liberal and individualist doctrines.
The defining characteristics of libertarian legal theory are its insistence that the amount of governmental intervention should be kept to a minimum and the primary functions of law should be enforcement of contracts and social order, though social order is often seen as a desirable side effect of a free market rather than a philosophical necessity.
Historically, the Austrian economist Friedrich Hayek is the most important libertarian legal theorist.
[citation needed] Another important predecessor was Lysander Spooner, a 19th-century American individualist anarchist and lawyer.
Ideas range from anarcho-capitalism to a minimal state providing physical protection and enforcement of contracts.