The self-ownership proviso

Introduction

Right-libertarians (libertarians for short ¹ ) are united in the view that persons are self-owners, that being self-owners, persons have rights over their talents and abilities, and that these rights justify property rights over whatever external resources their talents and abilities enable them to acquire. That said, libertarians are divided over what constraints, if any, apply to the acquisition of property. Robert Nozick (1974: 174–182) endorses Locke’s proviso that any acquisition of natural resources must leave ‘enough and as good’ for others (Locke, 1960: 288). Nozick takes this to mean that a person’s acquisition must not leave others worse off than they would have been prior to that acquisition. Nozick, however, is somewhat of an outlier. Many, if not most, libertarians reject any proviso on the acquisition of private property (Machan, 2009; Narveson, 1999, 2001; Paul, 1988; Rasmussen and Den Uyl, 1991; Rothbard, 1998, 2006; Sanders, 1987). As these libertarians see it, if what a person takes is truly in ‘the state of nature’, then how much a person takes, and what condition that leaves someone else in, is entirely irrelevant.

Both of these views have problems. Nozick’s endorsement of Locke’s proviso, given the rest of his views on justice, is at best, unmotivated, and at worst, inconsistent with those views. ² Alternatively, the no-proviso view has implications which are hard to swallow. According to this view, it would not be unjust for a person to acquire all the land surrounding another person, leaving the second person within the same confines as a typical jail cell. Any attempt by the second person to walk out of this ‘jail cell’ would be considered unjust trespassing. Can something like Locke’s proviso be motivated on libertarian grounds in a way that is both consistent and plausible?

Recently, Eric Mack (1995, 2002a, 2002b), Edward Feser (2005a, 2005b), and Daniel Russell (2010) have answered yes. ³ On their view, self-ownership justifies a constraint on the use of property: an owner’s use of property may not severely negate the ability of others to interact with the world. This constraint has been labeled by Mack the self-ownership proviso (SOP). The idea behind the proviso is that self-ownership requires that one be able to exercise her talents and abilities to some extent. And being able to exercise one’s talents and abilities requires access to external resources.

This view differs from Nozick’s view in a couple of ways. First, the SOP is only a restriction on property use, not acquisition (Feser, 2005a: 71; Mack, 1995: 191, 2002a: 98–103, 2002b: 245, 247; Russell, 2010: 161–162). The SOP is supposed to limit ownership in the sense that it limits the bundle of rights that are included in one’s ownership of a thing. A mere limit on ownership is not the same as a restriction on acquisition. If a restriction on acquisition is violated, that calls into question, entirely, a person’s title to a thing. However, when a person’s use of her property violates the SOP, her title to her property is not called into question.

A more significant difference between this view and Nozick’s is that this view endorses a proviso that is motivated by the libertarian’s core commitment to self-ownership. ⁴ In what follows, I will argue that this attempt to use self-ownership to ground a proviso similar to Locke’s fails. To be clear, what I will not be arguing is that such a proviso cannot be justified. Nor will I be arguing that there is no right against the severe negation of one’s ability to interact with the world. All I will be arguing is that any such proviso, and any such right, is not grounded in self-ownership. Libertarians must either adopt the no-proviso view or accept a proviso that is not grounded in self-ownership. The latter alternative, however, threatens to undermine the libertarian’s view.

The SOP

The bedrock of the libertarian theory of justice is the self-ownership thesis. ⁵ The self-ownership thesis states that each person is the rightful owner of herself, including her body and her mind. ⁶ The ownership involved includes all the components that attend the full ownership of an object: the right to use it and exclude others from using it, the right to dispose of it, immunity from others expropriating it, and the right to transfer ownership of it to someone else. This means that if I am a self-owner, I have the right to use my body and mind as I see fit, the right to exclude others from using my body and mind, the right to dispose of my body and mind if I so wish (if I wish to take my own life, you may not coercively prevent me), I am immune from others expropriating my body and mind (no one may force me into slavery), and I have the right to transfer ownership of my body and mind to someone else (I may voluntarily make myself someone’s slave). ⁷

Among those who subscribe to the self-ownership thesis, some (right-libertarians as opposed to left-libertarians ⁸ ) think that self-ownership justifies rights of external ownership (Feser, 2004: 34, 2005a: 66; Mack, 1983: 132, 2002a: 76, 2009: 101–102; Narveson, 2001: 81–85, 2010: 103–105, 115; Rasmussen and Den Uyl, 1991: 125–128; Rothbard, 1998: 48, 2006: 37; Russell, 2010: 136). Within this group, many (most?) are no-proviso libertarians. No-proviso libertarians think that justice places no restrictions on acquisitions of the (unowned) external world. And they believe that justice places no restrictions on how people may use what they acquire that go beyond those imposed by other people’s rights over their bodies and property. In contrast, those who endorse the SOP (SOP-libertarians), while also believing that justice does not place any restrictions on acquisitions of the (unowned) external world, do think that justice places restrictions on property use that go beyond those imposed by other people’s rights over their bodies and property. The point of departure for the two groups is over what count as violations of self-ownership. For no-proviso libertarians, a person’s self-ownership can only be violated invasively. Invasive violations of self-ownership include such things as assault, kidnapping, trespassing, and theft. All these things count as invasions of the ‘sphere’ around one’s person and property. SOP-libertarians, on the other hand, believe that self-ownership not only can be violated invasively but also noninvasively.

An example of what the SOP’s defenders have in mind by a noninvasive violation of self-ownership is presented by Mack (1995: 187–188) in a hypothetical case he refers to as Adam’s Island. In that scenario, a woman named Zelda has been shipwrecked and struggles to come ashore on an island, the whole of which belongs to Adam. ⁹ Adam, however, refuses to let Zelda ashore, asserting his property right over the island. By denying her access to his island, Adam severely negates Zelda’s capacity to exercise her talents and abilities. And by doing that, says the SOP-libertarian, Adam noninvasively violates Zelda’s self-ownership. Any property use that severely negates a person’s capacity to exercise her talents and abilities is a violation of that person’s self-ownership according to the SOP-libertarian. The SOP forbids this type of self-ownership violation.

‘Severely negates’ is clearly a vague notion, as the SOP’s defenders will admit. However, we can get some idea of what that notion refers to and, by implication, what counts as a SOP-violation. For instance, Adam’s Island suggests that blocking someone’s access to something they need in order to avoid impending death counts as severely negating a person’s ability to interact with the world and, hence, is a SOP-violation.

But the SOP is meant to rule out more than just blocked access which leads to someone’s immediate death. For example, the SOP is meant to prevent a certain kind of imprisonment. As an illustration, Mack presents another scenario where Adam noninvasively violates Zelda’s self-ownership, one that he calls Disabling Property Barrier:

While Zelda sleeps, Adam employs some of his rightfully held plastic…to construct a porous shell around her. Upon waking, she discovers that she is unable to break through this shell. When she attempts to free herself, Adam accuses her of trespassing on his plastic. (Mack, 1995: 195)

The SOP is intended to rule out additional forms of blocked access as well. According to Mack, if a cartel of property owners agrees ‘never to hire any black person for a nonagricultural job, and never to enter into any leasing arrangements or sales which would enable any black person to engage in nonagricultural endeavors’, then any black person who, as a result of this cartel’s agreement, is confined to agricultural work, suffers a SOP-violation (Mack, 1995: 215). As a guiding heuristic for identifying SOP-violations, Mack suggests checking whether or not the market is working out as well as market advocates expect markets will, in general, work out for people. He explains that market advocates expect that the market will generally increase a person’s ‘opportunities to bring her powers to bear on the world’ (Mack, 2002b: 249). But if the fact that a person’s opportunities are not increasing is supposed to raise a red flag, then the SOP appears to be a stronger requirement than one would have initially thought. A quote from an earlier piece by Mack better captures what I gather is the spirit of his proposed market heuristic:

For the SOP to be satisfied with respect to Zelda, she must have before her an array of occupational opportunities that is not strikingly more narrow than what the fan of market processes would predict for someone of Zelda’s talents, energies, and adaptability. (Mack, 1995: 215)

Although someone being in any of the situations just mentioned may raise a red flag for the SOP-libertarian, it is not necessarily seen by her as a problem as far as justice is concerned if the person’s situation has not come about as the result of blocked access. This is because the SOP does not entail an automatic entitlement to any given set of opportunities, level of well-being, or quantity of resources. Just like the no-proviso libertarian, the SOP-libertarian rejects any justice-based duty of assistance. For instance, in a case Mack calls Adam’s Unreachable Island, Zelda is unable to come ashore, so Adam never needs to assert his property rights – he just watches her drown. In this case, Mack says the SOP is not triggered, though there may be much to question about Adam’s character (Mack, 1995: 193). A ‘threefold distinction’ Mack draws should help explain the SOP-libertarian’s position. According to Mack, there are ‘(a) interferences by way of interventions against persons; (b) interferences by way of blockages against persons; and (c) failures to provide resources to persons’ (Mack, 2002b: 250). Only categories (a) and (b) include violations of self-ownership and are ruled out as unjust. (No-proviso libertarians only count the first category as violations of self-ownership and as ruled out by justice.)

Why is the SOP something libertarians should endorse? Mack offers two arguments. Subsequent adherents of the SOP have argued along similar lines. The first argument Mack calls the ‘top-down case’ and the second he calls the ‘bottom-up case’ (Mack, 1995: 191). I will present and critique each argument in turn.

The top-down case

The top-down case for the SOP as presented by Mack starts with the thought that as a self-owner, each person has a right over her talents and energies. A person’s talents and energies, Mack stresses, are world-interactive powers; they are a person’s ‘capacities to affect her extra-personal environment in accord with her purposes’ (Mack, 1995: 186). With respect to these powers, ‘[t]he presence of an extra-personal environment open to being affected by those powers is an essential element of their existence’ (Mack, 1995: 186). This means that a person’s world-interactive powers can be negated by others when they remove from that person access to an extra-personal environment upon which she could have otherwise exercised her talents and energies. Given this, respect for self-ownership prohibits property use that would negate, albeit noninvasively, another person’s talents and energies. That is, respect for self-ownership requires the SOP.

A key idea in this argument is Mack’s claim that our talents and energies require for their existence access to an extra-personal environment which they can be applied to. This claim needs to be examined. It is obviously true that for someone like Zelda in Adam’s Island, her lack of access to an extra-personal environment with which to apply her talents and energies means the loss of those talents and energies. But that is only true because for someone in Zelda’s situation, such lack of access means death. As we saw in the previous section, the SOP is not merely intended to rule out blocked access which leads to someone’s immediate death. It is also supposed to prevent blocked access in the form of imprisonment. In addition, as Mack’s proposed heuristic suggests, a person who has a ‘strikingly narrow’ set of opportunities, as a result of blocked access, is someone who has suffered a SOP-violation.

But if we set aside the threat of death, then in what sense do one’s talents and energies depend for their existence on an extra-personal world with which to engage with? Certainly not all our talents and energies are dependent in this way. After all, a basketball player still possesses her talents when she lacks access to a basketball. A photographer still possesses her talents even when she lacks a camera. And most of us never forget how to ride a bike, even if we haven’t ridden one for years.

A more charitable reading of Mack’s argument is that if we are unable to use our talents and energies, then we don’t really own them, and we can only use our talents and energies if we have access to an extra-personal environment with which to engage with. If we understand Mack’s argument this way, then we can account for the SOP’s prohibition of blocked access that does not lead to anyone’s immediate death. I will proceed, therefore, with this reading of Mack’s argument. So any reference to the nullification, negation, or disablement of one’s powers should be understood as a reference either to their literal going out of existence, the imminent threat of their going out of existence, or merely one’s inability to use them.

What I now wish to discuss is an objection to the SOP. The objection is that insofar as the SOP is meant to be an extension of the concept of self-ownership, the SOP-libertarian is committed to saying, for instance, that the ownership of a corkscrew entitles you to bottles of wine that you can open with it. Call this the corkscrew objection (Mack, 1995: 201). ¹¹ The assumption behind the corkscrew objection is that whether we are talking about ownership of the self or ownership of an object, the concept of ownership is the same in both cases. So if ownership of the self includes a right against the nullification of the self’s powers, then ownership in the case of an object (for example, a corkscrew) includes a right against the nullification of that object’s powers. But as the objection goes, it is bizarre to say that the ownership of an object includes a right against the nullification of that object’s powers. Therefore, it is equally bizarre to say that the ownership of the self includes a right against the nullification of the self’s powers. Noninvasive nullification of powers doesn’t violate ownership. That’s not part of the concept of ownership.

The immediate reaction I suspect most readers will have to this objection is that there is a clear disanalogy between the self and external objects such that a right against the nullification of a person’s powers is justified but not a right against the nullification of an object’s powers. Clearly, an agent has a greater stake in being able to exercise her powers than in being able to exercise the powers of any particular object she has. This explains why a right against the nullification of the self’s powers is warranted, while a right against the nullification of an object’s powers is not. But SOP-libertarians don’t just defend a right against the nullification of one’s powers. They argue that such a right is a part of self-ownership. Because of that, the corkscrew objection goes, it is SOP-libertarians who cannot account for the intuitive line of thought just presented. They can’t say that you have a right against the nullification of your powers without being committed to saying that you have a right against the nullification of your corkscrew’s powers.

In response to the corkscrew objection, the SOP-libertarian might argue that it is false to assume that the concept of ownership in the case of the self and in the case of an object must be the same. And so it shouldn’t matter that ownership of the self includes a right against the nullification of one’s powers, whereas ownership of an object does not include a right against the nullification of that object’s powers.

But the assumption behind the corkscrew objection is warranted. This is because the very concept of self-ownership is understood in terms of extending the notion of full ownership of an object to the self. As Peter Vallentyne says, ‘The core idea of full self-ownership is that agents own themselves in just the same way that they can fully own inanimate objects’ (Vallentyne, 2000: 2). This core idea is what makes self-ownership unique, interesting, and controversial. The reason, then, for assuming that the concept of ownership should be the same in both cases is because the very concept of self-ownership assumes as much.

A second response to the corkscrew objection might be that, although the concept of ownership is the same in both cases, there is a difference between the self and worldly objects such that ownership of the former includes a right against the nullification of one’s powers, whereas the ownership of an object does not include a right against the nullification of that object’s powers. The difference is that a person’s talents and energies can flourish with use and atrophy with disuse. By contrast, external property, like a corkscrew, retains its powers even with disuse. This difference justifies judging, from the perspective of justice, nullification of powers differently in the case of a person than in the case of external objects (Feser, 2005a: 75). Now, as we saw earlier, it is not obvious that lack of access to an extra-personal environment will always lead to the atrophy of one’s talents and energies. But even supposing that it does, this second response assumes that there are never cases where the powers of one’s external property atrophy with disuse. That is hardly a plausible assumption, as anyone with a car that hasn’t been driven for a long time will testify.

Finally, the SOP-libertarian might respond that it’s not so bizarre to attribute to the owner of an object a right against the nullification of that object’s powers. What could motivate that response is the thought that when others deny you access to things which your object’s powers could be directed upon, they are violating your right to use the object you own. No revision to our ordinary concept of ownership is even necessary – a right against the nullification of an object’s powers, or the self’s powers, is just an aspect of the right to use. But the right to use x which accompanies the ownership of x is commonly understood to prohibit invasive behavior on the part of others that prevents an owner from using her property, not noninvasive behavior. This explains why it is counterintuitive to think that someone’s refusal to sell you wine bottles is a violation of your right to use your corkscrew, whereas it is not counterintuitive to think of my snatching your corkscrew as you are about to open a wine bottle as a violation of your right to use your corkscrew.

But what if it were impossible for an owner of an object to secure access to things upon which her object’s powers may be directed? Suppose that all of the world’s wine sellers, grape-growers, and fertile land owners agree not to have any dealings with you. If, as this situation suggests, it is impossible for you to obtain wine bottles, maybe it is not all that bizarre to think that your ownership of your corkscrew has been violated. In this situation, the restrictions placed on the use of your corkscrew are noninvasive. So the thought that your ownership of your corkscrew is violated does necessitate revising our concept of ownership.

But perhaps our concept of ownership should be revised so as to include a right against nullification. There are two considerations that might motivate this move. One consideration is that the reason people acquire things in the first place is so that they can do things with them. No good comes from owning something if you can’t do anything with it. A second consideration concerns the justificatory grounds for ownership. Surely, the thought goes, whatever reasons we have for respecting the institution of ownership (on the unrevised understanding) are reasons for countenancing a right against nullification. An obvious reason for respecting ownership, one often invoked by libertarians, is our status as purposive agents. If that status justifies a person’s right against invasive interference with the use of the things one owns, it would also seem to justify a right against the noninvasive interference with the things one owns (at least to the point where I cannot use the thing or can barely make use of it). So both the point of ownership and the justification of ownership, one could argue, support revising our concept of ownership so that it includes a right against nullification.

As forceful as these considerations appear, I do not think that they justify revising the concept of ownership so as to include a right against nullification. ¹² Take for instance the point of ownership consideration. If the reasons people participate in an institution were enough to justify a right, then business owners must have the right to make a profit. After all, the point of owning a business is to turn a profit. No good comes from owning a business if one only incurs losses or breaks even. But clearly it would be absurd to revise our understanding of business ownership so as to include a right to make a profit. This means that the reasons why people participate in an institution do not determine what rights or advantages that institution ought to bestow.

The justification for ownership consideration also fails to justify revising the concept of ownership. It may be true that whatever value(s) justify ownership (ordinarily understood) also justify a right against nullification, but that does not entail treating the latter concept as part of the former. Two distinct concepts may have the same justificatory grounds: value A can justify rights X and Y. But it clearly does not follow that rights X and Y are the same or that one right falls, conceptually, under the other. ¹³

If one wants to capture the judgment that people have a right against the nullification of their world-interactive powers, it is not necessary that the concept of ownership be revised. There are already other concepts, or rather other values, that can capture that judgment. For instance, the value of autonomy, the idea that one’s choices ought to reflect the choices of an authentic self, can be understood to require that one’s choices not be limited in the way they are when one’s world-interactive powers are nullified. More straightforwardly, a minimal level of well-being, taken as a value, would mandate that people’s world-interactive powers not be nullified. ¹⁴

Turning to Russell, we see an argument very similar to Mack’s. Russell argues that embracing self-ownership while rejecting the SOP, as no-proviso libertarians do, is a failure to appreciate that the self, as Russell puts it, is ‘embodied’. The embodied view of the self, according to Russell,

has two central features: (1) the self is not just one’s psychology and power of choice, but extends also to one’s physical person; and, more provocatively, (2) the reasons that the self extends to one’s physical person are also reasons that the self extends into the world beyond one’s person. (Russell, 2010: 136)

Contrary to what Russell claims, there is no inconsistency between no-proviso libertarianism and the embodied view of the self. One can easily imagine a no-proviso libertarian appealing to the embodied view of the self as the reason for her view that self-ownership justifies external ownership. The disagreement between no-proviso libertarians and SOP-libertarians shouldn’t be seen as a disagreement over the embodied nature of the self but rather over what is entailed by ownership of an embodied self. For SOP-libertarians, ownership of an embodied self entails a right against the noninvasive nullification of the self’s powers, whereas for no-proviso libertarians, ownership of an embodied self entails no such right. Given the corkscrew objection, I think no-proviso libertarians are right on this issue.

No-proviso libertarians are right on this issue for another reason. Combining the embodied view of the self with the SOP has worrisome implications (certainly to libertarians, left and right) concerning the freedom to use one’s body. On the embodied view of the self, the self includes one’s body and things external to one’s body. If using parts of the self external to one’s body is restricted by the SOP, then why isn’t using one’s body parts similarly restricted by the SOP? Suppose that I need one of your kidneys to live, but you refuse to give me one of them, instead choosing to use both of them yourself. Are you not, then, choosing to use your kidney in such a way that my powers are negated? Call this the kidney objection. ¹⁵

Before going on to discuss Russell’s response to this objection and other possible responses, let me address an initial response that will probably occur to most readers. Most readers might think that Russell and like-minded SOP-libertarians could say that although the self includes both one’s body parts and things external to one’s body, nonetheless, one can distinguish between things that are more important and things that are less important to the self. The use of things that are less important to the self is subject to the SOP, whereas the use of things that are more important to the self is not subject to the SOP. And, the response continues, body parts are more important to the self and external parts are less important.

There are at least two problems with this proposal. First, it is not at all obvious that the distinction between things that are more important to the self and things that are less important to the self maps on to the distinction between body parts and external objects. However, we cash out ‘importance to the self’, it would be hard to see why a passionate musician’s guitar would be less important to her than any one of her toes. Second, the position that the distinctions are isomorphic is a position at odds with the embodied view of the self. That view is motivated by the idea that, as constituents of the self, there is a fundamental parity between our body parts and our external possessions. To take the view that external objects are less important, even if still parts of the self, is not to fully appreciate the self’s embodied nature.

Russell is aware of an objection to the SOP along the lines of the kidney objection. In response, he argues:

[T]his oversimplifies what the proviso actually does, which is to protect efforts to acquire not full stop, but in a way that is constrained by the fact that others are self-owners as well. Since the proviso protects opportunities to gain rights of use over things by appropriating them, the proviso protects opportunities only with respect to appropriable things, things that are not already owned. The thesis that persons own themselves, interpreted via the embodied conception of the self, automatically removes persons and what persons already own from the set of things that are appropriable and ripe for the picking. (Russell, 2010: 164)

The SOP-libertarian might respond that in the kidney case, and in similar cases, we need to be sensitive to the distinction between the constraints imposed by the SOP and those imposed by a duty of assistance. In the kidney case, only some duty of assistance could mandate that you offer me the use of your kidney, not the SOP. Perhaps this distinction is relevant if what were to occur in our scenario is that you don’t go out of your way to offer me the use of your kidney. This would be analogous to Adam’s Unreachable Island. However, suppose that in our scenario I actually attempt to get access to your kidney and you prevent me, while asserting your right to your body. This would be analogous to the original case, Adam’s Island, where Adam refuses to let Zelda come ashore. That case does involve a violation of the SOP. This shows that the SOP-libertarian can’t get around the kidney objection by appealing to the distinction between SOP-generated constraints and duties of assistance.

There is, however, another response that the SOP-libertarian might offer. She might argue that your keeping me from using your kidney does not violate the SOP because I would be just as badly off with respect to my powers if you had never existed or we had never come across each other. Mack appears to think that it is relevant for assessing whether or not a person in any situation has suffered a SOP-violation that that person would have been just as badly off with respect to her world-interactive powers if the property owner had been absent from that situation. For instance, Mack presents the following case, Adam’s Made Island, as an example where Adam’s treatment of Zelda does not violate the SOP:

Since his arrival at the previously unowned and uninhabited island, Adam has engaged in actions that, according to liberal theory, confer upon him sole dominion over all of the island. Indeed, he has so labored on the island – by building retaining walls, planting protective trees and grasses, and so on – that he has prevented the island from disappearing entirely into the sea. Now the innocent, shipwrecked Zelda struggles toward the island’s coast. But Adam refuses to allow Zelda to come ashore. (Mack, 1995: 193)

The view that Adam does not violate the SOP if Zelda would have been unable to exercise her powers in his absence leads to some unwelcome results for the SOP-libertarian. Imagine that Adam sees Zelda struggling to make it to shore. Upon seeing that she is not going to make it, he ventures out on a boat to rescue her and brings her back to his island. Once on his island, however, any time Zelda attempts to acquire food (for example, fruit hanging from trees) or use objects (for example, sticks to start a fire), Adam immediately stops her, claiming she is violating his property rights. On the face of it, this seems like a clear-cut case of a SOP-violation. But notice that if Adam had not been on the scene, Zelda would have been worse off with respect to her powers because she would have drowned. This entails that Adam’s treatment of Zelda is not a SOP-violation. I doubt any SOP-libertarian would be comfortable with that conclusion. So the SOP-libertarian may avoid the kidney objection by appealing to the requirement that a SOP-violation must make one worse off with respect to one’s powers than one would have been had the SOP-violator never existed. But that requirement itself includes unwelcome implications.

The bottom-up case

The intent of Mack’s bottom-up case is to demonstrate that the right of self-ownership should be understood to rule out noninvasive as well as invasive disablements of a person’s powers. Mack attempts this demonstration by trying to show similarities between violations of self-ownership, traditionally construed, and what would be violations of the SOP through several creative thought experiments. The first of these, Adam’s Island, has already been mentioned. Mack goes on to provide several other variants of Adam’s Island, each involving Zelda and each meant to blur the distinction between invasive and noninvasive disablement. For instance, in another case we’ve looked at, Disabling Property Barrier, Adam constructs a porous plastic shell around Zelda. Each time Zelda attempts to escape, Adam asserts that his property (his plastic) is being trespassed on. In Disabling Property Barriers, instead of placing her in a plastic shell, Adam encases all the objects that Zelda would otherwise use in plastic shells (Mack, 1995: 196). In Disabling Denial of Use without Barriers, whenever Zelda attempts to use an object, Adam uses a device to propel the object beyond her grasp (Mack, 1995: 197).

Again, the point of presenting all these cases is to blur the distinction between invasive and noninvasive disablement. Mack is arguing that there is no relevant difference between Adam’s treatment of Zelda in these cases and a case where Adam were to directly invade her ‘sphere’ by, say, grabbing her and placing her in a cage, or by assaulting and crippling her, or by destroying all her property. The right of self-ownership should rule out kidnapping, assault, and property destruction, as well as ruling out the way Adam treats Zelda in Adam’s Island and the other cases just mentioned. But on a narrow construal of self-ownership – one that prohibits only invasive disablements – the right of self-ownership wouldn’t prohibit such treatment. Only if the right of self-ownership rules out noninvasive disablements (and so includes the SOP), can self-ownership do the work it is supposed to do.

For reasons I gave in the last section, I believe it is mistaken to think that Zelda’s self-ownership is being threatened by Adam in Mack’s cases. But one might argue that the reasons I gave are outweighed by the intuitive support Mack’s cases provide for the claim that self-ownership can be violated noninvasively.

I do not, however, think it is so obvious that Mack’s Zelda cases do provide intuitive support for the claim that self-ownership can be violated noninvasively. What is intuitively obvious is that Zelda’s freedom to act is severely diminished in each case. But that is not necessarily a judgment that Zelda’s self-ownership is violated. Of course, there are several explanations for why one may be inclined to make that judgment. Nearly, every infringement of a person’s self-ownership diminishes that person’s freedom to act. The archetype of a person whose self-ownership is violated, a slave, is also the archetype of someone who isn’t free to act as she chooses. In addition, writers will often appeal to the same principle in order to justify self-ownership and calls for greater freedom (for example, the inviolability of persons). The reverse is also true. Writers will often appeal to either self-ownership or freedom in order to justify the same principle (for example, a right to private property). On top of all of this, libertarians frequently use ‘freedom’ or ‘liberty’ to mean self-ownership. ¹⁶

In light of the foregoing, it is easy to see why a person would draw the conclusion that the intuition that Zelda’s freedom to act is severely diminished is also an intuition that Zelda’s self-ownership is violated. Nonetheless, the judgment that someone’s freedom of action is severely diminished and the judgment that her self-ownership is violated are not identical. That is why the intuition that we all share, namely that Adam severely diminishes Zelda’s freedom of action, is consistent with the judgment that Adam does not violate Zelda’s self-ownership.

Conclusion

I have argued in this essay that the concept of self-ownership cannot plausibly be extended to include the SOP. One reason is because extending that concept to include the SOP has bizarre implications with respect to the concept of ownership broadly speaking. Another reason is that, when taken in conjunction with a view of the self (the embodied view of the self) intended to motivate it, the SOP has troublesome implications concerning the freedom to use one’s body parts. These objections are not overriden by appeals to intuitions in certain cases (for example, Mack’s Zelda cases) because it is not obvious those intuitions are about self-ownership as opposed to freedom.

Surprisingly, at one point Mack says, ‘nothing essential hinges on categorizing the claim against severe noninvasive nullification as a claim of self-ownership’ (Mack, 1995: 202). This quote suggests that Mack would be willing to concede to the argument of this essay, but in his view, nothing would be lost by the SOP-libertarian in doing so. In one sense, I agree with him. As I’ve said, nothing I argue here means that a right against nullification cannot be justified. Other values besides self-ownership can ground a right against nullification. Perhaps the same value justifies self-ownership (including property rights) and a right against nullification. On this view, although a right against nullification is no longer considered a part of self-ownership, the two come together as part of a package deal, so to speak.

But for all that, I do think the SOP-libertarian loses something if she were to concede that self-ownership does not justify a right against nullification, while clinging to the idea that such a right exists nevertheless. Adopting the view would mean abandoning the quest for a unified libertarian theory of property acquisition and use. As Mack himself says, the self-ownership thesis provides ‘a deep and unifying explanation for why all…sorts of actions ought to be condemned’ (Mack, 2002b: 262). Although the alternative route under consideration does not abandon the self-ownership thesis, it does abandon it as a ‘deep and unifying explanation’. That, however, is a minor point. The real worry is that by including a right against nullification along with self-ownership, it would involve including a right that could sometimes override self-ownership. (This is true insofar as one believes, as right-libertarians do, that external property rights are grounded in some way in self-ownership.) To illustrate, how Adam’s Island would be described on the alternative view. Zelda’s right against nullification would be seen as overriding Adam’s property right, and by extension, his self-ownership. It is in order to avoid such a view that Mack, Feser, and Russell argue on behalf of the self-ownership proviso. ¹⁷

But suppose the SOP-libertarian were willing to bite the bullet and come to terms with holding a view that countenanced instances where self-ownership can be overridden (by a right against nullification). The problem is that this would put the SOP-libertarian in a rather awkward position. Whereas before she had always been able to reject competing political values (for example, equality, community, and aggregate happiness) simply on the grounds that they conflict with self-ownership, now she would no longer be able to do so. Granted, believing that self-ownership can be overridden by one set of considerations does not commit one to believing that it can be overridden by any other set of considerations. But whatever story were told, there would need to be some explanation for why self-ownership can be overridden by a right against nullification and nothing else (not even a right to rescue). For my part, I’m skeptical that such an explanation could be provided.