Libertarianism is the view that agents initially morally fully own themselves and have certain moral powers to acquire property rights in external things. It can be understood as a basic moral principle or as a derivative one. For example, it can be advocated as a natural rights doctrine (e.g. Nozick 1974) or defended on the basis of rule consequentialism (e.g. Epstein 1998; Shapiro 2007) or rule contractarianism (e.g. Narveson 1988; Lomasky 1987). For concreteness, I shall here interpret libertarianism as a natural rights doctrine. For a full discussion of libertarianism, see Vallentyne (2010). For critical discussion of Nozick’s version of libertarianism, see Vallentyne (2011).

Although it has a long history (e.g. at least back to Locke 1960 [1689]), libertarianism was not widely discussed by political philosophers prior to Nozick (1974). Rawls, for example, does not explicitly discuss it at all in TJ and only briefly discusses it in PL (262–265). Nonetheless, Rawls’s discussion of the entitlement to one’s natural endowment is highly relevant to libertarianism’s assertion of self-ownership, and we shall focus on that issue.

Philosophers, unfortunately, use “justice” to mean several different things. Rawls used this term to mean, roughly, the moral permissibility (rightness) of basic structures, or social institutions creating profound and unavoidable effects on individuals’ lives (TJ 3–6, 93–98). By contrast, Nozick (1974, e.g. 52), and libertarians generally, tend to use “justice” to mean, roughly, infringes no one’s rights. Thus, it’s not clear that they are addressing the same topic.