Anarchist law is a body of norms regarding behavior and decision-making that might be operative in an anarchist community. The term is used in a series of ongoing debates within the various branches of anarchist theory regarding if and how norms of individual and/or collective behavior, decision-making and actions should be created and enforced. Although many anarchists would consider "anarchist law" simply synonymous with natural law, others contend law in anarchy would have additional, unique elements. Over the course of the last two hundred years as anarchism has grown and evolved to include diverse strains, there have been different conceptions of "anarchist law" produced and discussed, or used in practice by anarchist networks such as Peoples' Global Action or Indymedia.
The most fundamental maxim of many anarchist tendencies is that no individual has the right to coerce another individual. Including the state, capitalism, or systematic oppression and that everyone has the right to defend themselves against coercion (the non-aggression principle or zero aggression principle). This basic principle, like mutual aid, is built upon much of anarchist law, and indeed much of anarchist theory. Peter Kropotkin, a prominent anarcho-communist, stated it was "It is best summed up by the maxim 'do unto others as you would have them do unto you.'" In short, anarchist philosophy includes the "Ethic of reciprocity", but typically does not include "turning the other cheek" towards violence of forms of oppression (with the exception of Anarcho pacifism and sometimes Christian anarchism and other nonviolent/pacifistic movements).
Since the principle of non-coercion makes hierarchical state structures unfeasible, anarchist communities must find an alternative basis for setting the rules of engagement within a collective. Accordingly, virtually all anarchist legal models begin with the assumption that whatever rules are set in place must be freely agreed to by the entirety of the community that is to be governed by them in a setting free from coercion or intimidation. Such freely given consent constitutes a social contract, though the exact nature of such contracts is a matter of heated debate.[page needed]
However, many anarchist theorists completely reject natural law as capitalistic and man made. Natural law in this view is disguising authoritarianism but blaming it on an abstract entity so that the "anarchist" does not have to take credit for it. Social anarchists, mutualists and many individualist anarchists reject private property, which is the core basis of most natural law theories.
Free association (also called voluntary association) also implies the right of individuals to form those exact social contracts. This freedom to not associate means if the terms of a social contract become unacceptable to an individual member or sub-group(s) within a society, the discontented have the right to secede from the contract. They may also form new associations with others that more closely fit their needs.
The principle of mutual aid, originally identified by Peter Kropotkin as arising from natural law, is that since evolution occurs in groups – not individuals – it is evolutionarily advantageous for members of a community to assist each other. The anarchist approach to building power – and structuring power relationships – is derived from this evolutionary and biological imperative. In a nutshell the argument is that since individuals require the assistance of groups to self-actualize, individuals have a strong self-interest in the good of the community to which they belong. It follows that (freely associating) collectives of individuals working for mutual improvement and mutual goals must form the basis of any anarchist society, thus providing the sociological and economic imperative for the creation of social contracts capable of binding these self-selecting groups together.
In a pre-revolutionary situation, the principle of "mutual aid" is the moral imperative that drives efforts by contemporary anarchists to provide material aid to victims of natural disasters; those that are homeless or poor, and others who have been left without access to food or clean drinking water, or other basic necessities.
Enforceability is one of the most controversial areas of Anarchist law. Early writers such as Proudhon argued that it was legitimate for working-class people to self-organize against criminals who prey on the weak, a process which would unequivocally entail some degree of coercion.
Proudhonian mutualists (and many others) have argued that such use of force by a collective against individuals is justifiable since it is fundamentally defensive in nature. As a more coherent example, communities have a clear interest in tracking down and isolating rapists, murderers, robbers and others who regularly employ coercion against their victims. The right of ordinary people to not be victimized and coerced by such individuals legitimizes their use of coercive force to eliminate such threats. Some individualist anarchists (who argue that any collective action against an individual is illegitimate) hotly dispute this point.
The issue of mandate (on whose behalf an action is being carried out) is much more significant, however, when approaching larger-scale provisions for self-defense such as armies and militias. For individualist anarchists the right of individuals to not be coerced legitimizes the use of coercive violence for personal self-defense only, while for collectivists it is legitimized both for personal self-defense and for defense of ones community. This issue is critical since, while the individualist model makes warfare far less likely by eliminating the rationale for the creation of large bodies of armed men, the collectivist approach makes it much more likely that the community in question will be able to defend itself against a hostile invader should one appear.
Both schools, however, agree that the right and responsibility of self-defense cannot be delegated to a third party – such as a professional police department or standing army – since as soon as a third party becomes involved it is no longer self defense. A non-hierarchical militia composed of members of a community self-organizing for mutual self-defense against a hostile neighbor (such as that organized by the CNT during the Spanish Civil War) would thus be valid in a collectivist (anarchist-communist, social anarchist, anarcho-syndicalist, market-syndicalist, etc.) setting and deemed invalid in an individualist (free market anarchist, egoist, etc.) setting if involuntary. Both, by contrast, would reject a standing army or police department.
Common techniques for decision-making, including decisions about the de facto laws themselves, among non-hierarchical societies include various forms of formal consensus, supermajority voting, "consensus minus one" and direct democracy. Anthropologist David Graeber argues that any community that lacks a centralized mechanism of force (a state) will naturally gravitate toward some form of consensus decision-making.