First published Thu Sep 5, 2002; substantive revision Tue Jul 20, 2010

Libertarianism, in the strict sense, is the moral view that agents initially fully own themselves and have certain moral powers to acquire property rights in external things. In a looser sense, libertarianism is any view that approximates the strict view. This entry will focus on libertarianism in the strict sense. For excellent discussion of the liberty tradition more generally (including classical liberalism), see Gaus and Mack (2004) and Barnett (2004).

Libertarianism is sometimes identified with the principle that each agent has a right to maximum equal empirical negative liberty, where empirical negative liberty is the absence of forcible interference from other agents when one attempts to do things. (See, for example, Narveson 1988, 2000, Steiner 1994, and Narveson and Sterba 2010.) This is sometimes called Spencerian Libertarianism (after Herbert Spencer). It is usually claimed that this view is equivalent to above self-ownership version of libertarianism. Kagan (1994), however, has cogently argued that the former (depending on the interpretation) either leads to radical pacifism (the use of force is never permissible) or is compatible with a wide range of views in addition to the above self-ownership libertarianism. I shall not, however, attempt to assess this issue here. Instead, I shall simply focus on the above self-ownership version of libertarianism.

Libertarianism can be understood as a basic moral principle or as a derivative one. It might, for example, be advocated as a basic natural rights doctrine. Alternatively, it might be defended on the basis of rule consequentialism or teleology (e.g., Epstein 1995, 1998; Rasmussen and Den Uyl 2005; or Shapiro 2007) or rule contractarianism (e.g., Narveson 1988 and roughly Lomasky 1987). Instrumental derivations of libertarianism appeal to considerations such as human limitations (e.g., of knowledge and motivation), incentive effects, administrative costs, the intrinsic value of liberty for the good life, etc. This entry will not address arguments for libertarian principles on the basis of other moral principles. Instead, it will simply address the plausibility of libertarian principles in their own right.

Although libertarianism could be advocated as a full theory of moral permissibility, it is almost always advocated as a theory of justice in one of two senses. In one sense, justice is concerned with the moral duties that we owe others. It does not address impersonal duties (duties owed to no one) or duties owed to self. In a second sense, justice is concerned with the morally enforceable duties that we have. It does not address duties for which it is impermissible to use force to ensure compliance or to rectify (e.g., punish) non-compliance (e.g. a duty to see your mother on her birthday). We shall here consider libertarianism as a theory of justice in each sense.

Libertarianism is often thought of as right-wing doctrine. This, however, is mistaken for at least two reasons. First, on socialrather than economicissues, libertarianism tends to be left-wing. It opposes laws that restrict consensual and private sexual relationships between adults (e.g., gay sex, extra-marital sex, and deviant sex), laws that restrict drug use, laws that impose religious views or practices on individuals, and compulsory military service. Second, in addition to the better-known version of libertarianismright-libertarianismthere is also a version known as left-libertarianism. Both endorse full self-ownership, but they differ with respect to the powers agents have to appropriate unowned natural resources (land, air, water, minerals, etc.). Right-libertarianism holds that typically such resources may be appropriated by the first person who discovers them, mixes her labor with them, or merely claims themwithout the consent of others, and with little or no payment to them. Left-libertarianism, by contrast, holds that unappropriated natural resources belong to everyone in some egalitarian manner. It can, for example, require those who claim rights over natural resources to make a payment to others for the value of those rights. This can provide the basis for a kind of egalitarian redistribution.

The best known early statement of (something close to) libertarianism is Locke (1690). The most influential contemporary work is Nozick (1974).

Libertarianism holds that agents are, at least initially, full self-owners. Agents are (moral) full self-owners just in case they morally own themselves in just the same way that they can morally fully own inanimate objects. Below we shall distinguish between full (interpersonal) self-ownership and full political self-ownership. Many versions of libertarianism endorse only the latter.

Full ownership of an entity consists of a full set of the following ownership rights: (1) control rights over the use of the entity: both a liberty-right to use it and a claim-right that others not use it, (2) rights to compensation if someone uses the entity without one's permission, (3) enforcement rights (e.g., rights of prior restraint if someone is about to violate these rights), (4) rights to transfer these rights to others (by sale, rental, gift, or loan), and (5) immunities to the non-consensual loss of these rights. Full ownership is simply a logically strongest set of ownership rights over a thing. There is some indeterminacy in this notion (since there can be more than one strongest set of such rights), but there is a determinate core set of rights (see below).

At the core of full self-ownership, then, is full control self-ownership, the full right to control the use of one's person. Something like control self-ownership is arguably needed to recognize the fact there are some things (e.g., various forms of physical contact) that may not be done to a person without her consent, but which may be done with that consent. It wrongs an individual to subject her to non-consensual and unprovoked killing, maiming, enslavement, or forcible manipulation.

Here is the original post:

Libertarianism (Stanford Encyclopedia of Philosophy)