The Non-Aggression Principle[a] (NAP) is a concept in which "aggression" – defined as initiating or threatening any forceful interference with an individual, their property[b] or their agreements (contracts) – is illegitimate and should be prohibited.
[4][5][6][7][non-primary source needed] The principle has been derived through various philosophical approaches, including: Libertarians who are pro-life and pro-choice both justify their position on NAP grounds.
They refer to the animal rights discussion and point out the argument from marginal cases that concludes the NAP also applies to non-sentient (i.e. mentally handicapped) humans.
[16] Objectivist philosopher Leonard Peikoff has argued that a fetus has no right to life inside the womb because it is not an "independently existing, biologically formed organism, let alone a person".
[17] Pro-choice libertarian Murray Rothbard held the same stance, maintaining that abortion is justified at any time during pregnancy if the fetus is no longer welcome inside its mother.
Libertarian theorist Walter Block follows this line of argument with his theory of evictionism, but he makes a distinction between evicting the fetus prematurely so that it dies and actively killing it.
][25] The debate centers on topics such as the age of consent for children,[26][27][28] intervention counseling (i.e. for addicted persons, or in case of domestic violence),[29][30] involuntary commitment and involuntary treatment with regards to mental illness,[31] medical assistance (i.e. prolonged life support vs euthanasia in general and for the senile or comatose in particular),[32][33] human organ trade,[34][35][36] state paternalism (including economic interventionism)[37][38][39] and foreign intervention by states.
In order to avoid having mere existence violate the non-aggression principle, Rothbard, Nozick, and others proposed less strict positions.
[2] Some libertarians justify the existence of a minimal state on the grounds that anarcho-capitalism implies that the non-aggression principle is optional because the enforcement of laws is open to competition.
[49][50][51] Therefore, anarcho-capitalists claim that in practice, and in more advanced societies with large institutions that have a responsibility to protect their vested interests, disputes are most likely to be settled peacefully.
[52][53] Anarcho-capitalists also point out that a state monopoly of law enforcement does not necessarily make NAP present throughout society as corruption and corporatism, as well as lobby group clientelism in democracies, favor only certain people or organizations.
Anarcho-capitalists argue that the protection of individuals against aggression is self-sustaining like any other valuable service, and that it can be supplied without coercion by the free market much more effectively and efficiently than by a government monopoly.
[56] Their approach, based on proportionality in justice and damage compensation, argues that full restitution is compatible with both retributivism and a utilitarian degree of deterrence while consistently maintaining NAP in a society.
Libertarian academic philosophers have noted the implausible results consistently applying the principle yields: for example, Professor Matt Zwolinski notes that, because pollution necessarily violates the NAP by encroaching (even if slightly) on other people's property, consistently applying the NAP would prohibit driving, starting a fire, and other activities necessary to the maintenance of industrial society.
[62][63][64][65][66][67][68] The NAP has been criticized as circular reasoning and a rhetorical obfuscation of the coercive nature of right-libertarian property law enforcement because the principle redefines aggression in their own terms.
In arguing against the NAP, philosopher Matt Zwolinski has proposed the following scenario: "Suppose that by imposing a very, very small tax on billionaires, I could provide life-saving vaccination for tens of thousands of desperately poor children.
Citing David D. Friedman, Zwolinski notes that the NAP is unable to place a sensible limitation on risk-creating behavior, arguing: Of course, almost everything we do imposes some risk of harm on innocent persons.
Thus a starving man may, in consonance with general morality, break into a hunting cabin and steal food, but nevertheless he is aggressing, i.e., violating the NAP, and (by most rectification theories) should pay compensation.
[71] Critics argue that the legal rights approach might allow people who can afford to pay a sufficiently large amount of compensation to get away with murder.
[50] Other critics state that the NAP is unethical because it does not provide for the violent prohibition of, and thereby supposedly legitimizes, several forms of aggression that do not involve intrusion on property rights such as verbal sexual harassment, defamation, boycotting, noninvasive striking etc.
Supporters cite the theoretical "tragedy of the commons"[clarification needed] and argue that free-market environmentalism will be much more effective in conserving nature.
[89] Consequentialist libertarian David D. Friedman, who believes that the NAP should be understood as a relative rather than absolute principle, defends his view by using a sorites argument.