Peter Vallentyne

Over the past few decades, there has been increasing interest in left- libertarianism, which holds (roughly) that agents fully own themselves and that natural resources (land, minerals, air, and the like) belong to everyone in some egalitarian sense. Left-libertarianism agrees with the more familiar right-libertarianism about self-ownership, but radically disagrees with it about the power to acquire ownership of natural resources. Merely being the first person to claim, discover, or mix labor with an unappropriated natural resource does not—left-libertarianism insists—generate a full private property right in that natural resource. Left-libertarianism seems promising because it recognizes both strong individual rights of liberty and security and also grounds a strong demand for some kind of material equality. It seems, that is, to be a plausible a form of liberal egalitarianism. In a recent review essay of a two-volume anthology on left-libertarianism (edited by two of us), Barbara Fried has insightfully laid out most of the core issues that confront left-libertarianism.1 We are each left-libertarians, and we would like to take this opportunity to address some of the general issues that she raises. We shall focus, as Fried does much of the time, on the question of whether left-libertarianism is a well-defined and distinct alternative to existing forms of liberal egalitarianism. More specifically, we shall address the following fundamental issues raised by Fried (and others): (1) Does the notion of self-ownership have any determinate content? (2) What is the relation between self-ownership and world ownership? (3) How is left-libertarianism different from other forms of liberal egalitarianism (e.g., those of Rawls and Dworkin)? First, however, we shall set the context by providing some general background on left-libertarianism.

Individuals who have not intruded, and who do not risk intruding, upon the rights of others, normally are wronged by harmful non-consensual neurointerventions. Nonetheless, this chapter argues that neurointerventions sometimes do not wrong the intervenee; namely, when (1) suitably valid consent has been given by the intervenee, or (2) the intervenee risks non-rightfully intruding upon the rights of others and the intervention is proportionate and necessary for suitably reducing the intrusion-harms she imposes, or (3) the intervenee is _not_ psychologically autonomous and the intervention is in her interests. Moreover, in the second case, it _wrongs_ an individual to impose harmful non-consensual _alternatives to neurointerventions_ (such as incarceration) when they impose greater intrusion-harm on the individual and do not achieve a greater reduction in the relevant intrusion-harm she imposes.

Chapter 5 discusses the implications of libertarianism for just taxation. Libertarianism holds that agents fully own themselves and have certain moral powers to appropriate natural or abandoned resources. Some versions of libertarianism preclude the possibility of just taxation, but the author claims that other versions can, under very limited circumstances, endorse two kinds of taxes as just: taxes on right-infringers for the cost of rights-enforcement and taxes on anyone with an excess share of the value ownership rights over natural resources. Other kinds of taxation, such as income taxes, human resource (talents) taxes, and artifactual resource taxation are not just on any version of libertarianism.

This chapter addresses the question of how false or incomplete beliefs affect agent-responsibility for outcomes. For simplicity, the agent is assumed not to be responsible for her false beliefs. One possible effect of false beliefs is that some outcomes will be unforeseen. It is generally recognized that agents are not responsible for unforeseen impacts and this chapter assumes that this is correct. A second possible effect of false beliefs is that the agent will falsely imagine there to be certain impacts. It is argued (with some qualifications) that imaginary impacts are excusing conditions that reduce or eliminate responsibility for outcomes but can never enhance responsibility for outcomes.

Whether justice requires, or even permits, a basic income depends on two issues: 1. Does justice permit taxation to generate revenues for distribution to others? 2. If so, does justice require, or even permit, equal and unconditional distribution for some portion of the tax revenues? I claim the following: 1. although all forms of libertarianism reject the nonconsensual taxation of labor and the products of labor, all but radical right-libertarianism allow a kind of wealth taxation for rights over natural resources, and 2. some versions of libertarianism allow the equal and unconditional distribution of such revenues and some do not.

This chapter develops an account of enforcement rights against nonculpable intruders, and extends it to include rights against culpable violators. It extends the discussion to include enforcement rights to defend others. The extended account holds that an agent has an enforcement right to intrude against another if the defensive intrusion suitably reduces nonjust intrusion-harm to the agent or others, is no more harmful to the other than necessary to achieve the reduction, and imposes intrusion-harm on the other that is proportionate in a specified manner to the reduction achieved. The crux of the theory comes from the proportionality conditions, which are sensitive to whether the individual will be intruding upon rights, the degree of responsibility for intrusion-harm, and the degree of culpability.