Abortion Propertarians/Right-libertarians who are pro-life and pro-choice both justify their position on NAP grounds. One question to determine whether or not abortion is consistent with the NAP is at what stage of development a fertilized human egg cell can be considered a
human being with the status and rights attributed to
personhood. Some supporters of the NAP argue this occurs at the moment of conception while others argue that since the fetus lacks
sentience until a certain stage of development, it does not qualify as a human being and may be considered property of the mother. On the other hand,
opponents of abortion state that sentience is not a qualifying factor. 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. Another question is whether an unwelcome fetus should be considered to be an unauthorized trespasser in its mother's body. The non-aggression principle does not protect trespassers from the owners of the property on which they are trespassing.
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".
Pro-choice propertarian/right-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. Similarly, other pro-choice supporters base their argument on criminal trespass. In that case, they claim that the NAP is not violated when the fetus is forcibly removed, with deadly force if need be, from the mother's body, just as the NAP is not violated when an owner removes from the owner's property an unwanted visitor who is not willing to leave voluntarily. 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. On the other hand, the theory of
departurism permits only the non-lethal eviction of the trespassing fetus during a normal pregnancy.
Pro-life libertarians such as
Libertarians for Life argue that because the parents were actively involved in creating a new human life and that life has not consented to their own existence, that life is in the womb by necessity and no parasitism or trespassing in the form of legal
necessity is involved. They state that as the parents are responsible for that life's position, the NAP would be violated when that life is killed with abortive techniques.
Intellectual property rights The NAP is applicable to any unauthorized actions towards a person's physical property. Supporters of the NAP disagree on whether it should apply to
intellectual property rights as well as physical property rights. Some argue that because intellectual concepts are non-
rivalrous, intellectual property rights are unnecessary while others argue that intellectual property rights are as valid and important as physical ones.
Force and interventions Although the NAP is meant to guarantee an individual's sovereignty, propertarians/right-libertarians greatly differ on the conditions under which the NAP applies. Especially unsolicited intervention by others, either to prevent society from being harmed by the individual's actions or to prevent an incompetent individual from being harmed by his own actions or inactions, is an important issue. The debate centers on topics such as the
age of consent for children,
intervention counseling (i.e. for addicted persons, or in case of domestic violence),
involuntary commitment and
involuntary treatment with regards to
mental illness,
medical assistance (i.e. prolonged life support vs euthanasia in general and for the senile or comatose in particular),
human organ trade,
state paternalism (including
economic interventionism) and
foreign intervention by states. Other discussion topics on whether intervention is in line with the NAP include
nuclear weapons proliferation,
human trafficking and
immigration.
Objectivist author Ronald Merill criticizes the anarcho-capitalist view of force. He states that the use of force is subjective, saying: "There's no objective basis for controlling the use of force. Your belief that you're using force to protect yourself is just an opinion; what if it is my opinion that you are violating my rights?"
Pollution Prominent propertarian/right-libertarian thinkers such as
Murray Rothbard considered pollution an act of aggression, mostly focusing on
air pollution, though in absolute terms
light pollution, sound, and anything that crosses a boundary into someone's property or person can constitute aggression. In order to avoid having mere existence violate the non-aggression principle, Rothbard, Nozick, and others proposed less strict positions. Nozick suggested that boundary-crossing is permissible up to a certain range as long as it is socially beneficial and compensation is paid for it. Rothbard suggested that a causal connection of objective harm needs to be demonstrated beyond reasonable doubt before prohibiting pollution. These approaches
appear to contradict the non-aggression principle by enabling a permissible amount of harm.
Anarcho-capitalists usually respond to this argument that this presumed outcome of what they call "coercive competition" (e.g.,
private military companies or
private defense agencies that enforce
local law) is not likely because of the very high cost, in lives and economically, of war. They claim that war drains those involved and leaves non-combatant parties as the most powerful, economically and militarily, ready to take over. 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. 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 aligned with the
Rothbardian philosophy generally contend that the state violates the non-aggression principle by its very nature because, it is argued, governments necessarily use force against those who have not
stolen private property,
vandalized private property,
assaulted anyone, or
committed fraud.
Taxation Some proponents of the NAP see
taxes as a
violation of the NAP, while critics of the NAP argue that because of the
free-rider problem in case security is a
public good, enough funds would not be obtainable by voluntary means to protect individuals from aggression of a greater severity.
Geolibertarians, who following the
classical economists and
Georgists adhere to the
Lockean labor theory of property, argue that private ownership of land violates the NAP, and therefore
land value taxation is fully compatible with the NAP.
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. 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. They extend their argument to all public goods and services traditionally funded through taxation, like security offered by dikes. == Support ==